THE COMPLETE WORKS OF JOHN HUNTER, F.R.S.
Edited by James F. Palmer. Philadelphia: Haswell, Barrington, and Haswell; New York: J. & H. G. Langley, 1841.
Four volumes. OCR text from the U.S. National Library of Medicine, NLM Unique ID 56830590R.
====================================================================================================



====================================================================================================
VOLUME I
The Life of Hunter by Drewry Ottley; Lectures on the Principles of Surgery (notes by James F. Palmer)
====================================================================================================

IF* ARMY MEDICAL LIBRARY

JAMES F. PALMER, SENIOR SURGEON TO THE ST. GEORGE'S AND ST. JAMEs's'DISPENSARY, FELLOW OF THE HOTAL MEDICAL AND CHIRURGICAL SOCIETY OF LONDON, ETC., ETC. VOL. I. ILLUSTRATED WITH NUMEROUS ENGRAVINGS. THE LIFE OF HUNTER BY DREWRY OTTLEY.

LECTURES ON THE PRINCIPLES OF SURGERY; WITH NOTES BY JAMES F. PALMER. JiMu latf cIjjU fa : HASWELL, BARRINGTON, AND HASWELL. NEW YORK: J. & H. G. LANGLEY. 1841. wz 2<rT

m\ v./ i THE LIFE JOHN HUNTER, F.R.S. ^ «a«c*v " " DREWRY OTTLEY. ."""'LIBRARY 1 SURGEON GENERAL'S OFFICE

HASWELL, BARRINGTON, AND HASWELL, 393 MARKET STREET. 1841. / PREFATORY ADVERTISEMENT. Those who have traced the progress of modern surgery to its true source will not fail to have discerned, in the principles which Hunter established, the germs of almost all the improvements which have been since introduced. Like a wise ' master-builder, he laid the foundation of the profession upon so broad a basis that it has withstood the attacks of adversaries and the versatility of public opin«- ion not only uninjured, but with fresh accession of fame to himself, and (with few exceptions,) the most complete verification of his opinions. The strict T inductive method of reasoning Avhich he pursued, upon physiological subjects, I led the way to juster modes of investigation; the zeal which he evinced stimulated many ardent followers in the path which he had opened, and the principles which he inculcated became the fruitful source of an infinity of practical applications, which were capable of being worked out by inferior minds. Thus the fame of Hunter, after a lapse of nearly half a century, is rather augmented than diminished by each succeeding year: the country which gave him birth is justly proud of his name; and those who have shown the deepest insight into the principles of their profession, and made the greatest improvements in the practice of it, have ever been most forward in celebrating his merits. But it is unnecessary to enlarge further on the celebrity of this distinguished philosopher, of whom it has been truly said, that "he was the greatest man in the combined character of physiologist and surgeon that the whole annals of* medicine can furnish."* For a more full account of the character of Hunter's genius, and the peculiarities of his works, the Editor begs leave to refer the reader to the ensuing memoir, in which the language of indiscriminate panegyric, so freely employed by his preceding biographers, has given place to the voice of truth. His merits have been weighed in a just balance, and the less favourable parts of his character, as a man and as a philosopher, pointed out without disguise. The reconstruction and enlargement of the Hunterian Museum, together with the publication of well-digested catalogues of its contents, seem well calculated to extend the fame of its founder, as well as to fix it on a more rational foundatipn. To the Editor these circumstances have appeared to afford a favourable occasion for the re-publication of Mr. Hunter's writings, considering that as all his labours were directed to the elucidation of the laws of life, they can only be advantageously studied in their totality. Those, therefore, who have familiarized themselves with his style and mode of thought, as displayed in his writings, possess the best clue to his museum; as, on the other hand, those who have made themselves well acquainted with the contents of his museum, possess the best guide in the perusal of his works. The two may be regarded as forming necessary parts of that general undertaking in which the author was engaged; his writings forming the text to his museum,—his museum the appropriate illustration of his writings. It cannot but be a subject of deep regret to all those who have the interest of science or of their profession at heart, that no one should have undertaken to collect these, writings before. Dispersed through scattered volumes of the Transactions of the Royal and other learned Societies, many of his most valuable papers have been unknown or neglected, or at least have been inaccessible to the great bulk of the profession ; while of those which have been published separately, some are nearly out of print and scarcely to be obtained, others are extremely incorrect, and the greater number are excluded from general circula- * Lawrence. 4 ADVERTISEMENT. tion in consequence of their expensive form or inconvenient bulk. To remove these disadvantages, by presenting to the profession a cheap and correct edition of the author's whole works, has been one of the principal objects of the present edition. It was considered that the utility of the work would be greatly promoted by an incorporation of the most important results of modern discoveries, in the form of foot notes ; and in the prosecution of this part of his scheme the Editor has to acknowledge the able assistance of several distinguished friends, whose particular acquaintance with the subjects which they have respectively undertaken is well known to the public. As far as possible brevity has been consulted, and it is scarcely necessary to add, that each gentleman is alone responsible for the opinions contained in his own notes. The superiority of the present edition above all the preceding will appear from the following particulars :— 1. It embraces the whole of Mr. Hunter's published works. 2. It contains a full and collated copy of his Surgical and Croonian Lectures. 3. It is preceded by a new life of the author, containing original anecdotes, a critical disquisition concerning the character and writings of the author, and a summary exposition of his Museum; to which has also been added Mr. Hunter's correspondence with Dr. ,Jenner and Sir Joseph Banks. 4. It is illustrated by numerous engravings. 5. The whole work is accompanied by illustrative notes, with the purpose of supplying such deficiencies as the progress of science has rendered necessary. 6. The text has been corrected, the punctuation rectified, and the modern synonyms introduced. Obscurities (so far as they have appeared to depend on improprieties of expression,) have been obviated, and a copious index has been added to the whoje. 7. The work has been printed in a clear and legible type, at the same time that the size and price of the Edition, and the manner of its publication, have been accommodated to the convenience of purchasers. Having thus stated the design and object of the undertaking, it is hoped that the reader will not be disappointed in his expectations. The writer is well aware that the works of so great a master deserve a much more learned and critical Editor than he can pretend to be. He begs, however, that it may be borne in mind, that so far as he is concerned, the work is not designed for those who have completed, but for those who are commencing their profession, and if he has failed in the execution of his task, he at least will have the satisfaction of having attempted a good work, which ought, in his opinion, to have been loner since finished by a more able hand. J. F. PALMER. LIFE OF JOHN HUNTER, F.R.S. CONTENTS. Introduction to the Life ........ 9 CHAPTER I.

Mr. Hunter's birth and family;—his early habits.—Dr. Wm. Hunter's rise to fame;—his difficulties at the outset of life.—Mr. Hunter's arrival in London; —his rapid acquisition of anatomical knowledge;—becomes a,pupil ofCheselden.—Cheselden's mode of operating for stone;—his character and death.— Mr. Hunter's employments at this period ;—the advantages which he derives from his brother's society ........ 11 CHAPTER II.

Hunter becomes a pupil of Pott.—Pott's character as a Surgeon.—Hunter enters at St. Mary's Hall, Oxford;—enters as a pupil at St. George's Hospital;— discovers the mode of connexion between the placenta and uterus;—his conduct as a lecturer and demonstrator of anatomy.—Disputes of the Hunters with contemporaneous anatomists respecting the anatomy of the testes, the office of the lymphatics, and the hernia congenita.—Hunter traces the nerves of the nose;—his experiments on the subject of venous absorption;—commences the pursuit of comparative anatomy;—embarks for Belleisle;—is still ardent in the pursuit of science.—Jesse Foot and his Life of Hunter . 18 CHAPTER III.

Hunter settles in London.—Alienation between the brothers.—His straitened circumstances ;—his favourable position in other respects.—Patience and fortitude required of young surgeons.—Obstacles to Hunter's success;—his contempt of humbug;—his thirst for fame and knowledge greater than his o 6 THE LIFE OF JOHN HUNTER. love of wealth ;—delivers lectures on anatomy ;—his persevering industry.— The state of surgery at this period.—The plan of his vast future labours conceived and entered upon.—The Baconian philosophy—Earl's Court.—His encounter with a bull and two leopards ;—is made F.R.S.—His description of the Proteus ;—ruptures his tendo-Achillis ;—is elected surgeon to St. George's Hospital;—removes to Jermyn-street.—Dr. Hunter's liberal offer to the Government rejected.—Mr. Hunter's house-pupils.—The pupils of distinguished surgeons themselves become distinguished.—Dr. Jenner;—his immortal discovery of vaccination.—Mr. Hunter's treatise on the teeth;—his marriage. Mrs. Hunter...........95 CHAPTER IV.

Mr. Hunter's paper on the digestion of the stomach ;—his museum ;—his private practice;—his illness, attended with a cessation of the heart's action;—his correspondence with Dr. Jenner;—his paper on the torpedo ;—his lectures on surgery ;—his character as a lecturer.—Hunter effects a revolution in surgery ; —his paper on the receptacles for air in birds, and on the stomach of the gillaroo trout.—The general character of his monographs.—Mr. Bell,—Mr. Hunter's warmth of temper;—his method of employing his time ;—his punctuality.—Anecdote of Mr. Cline.—Dictates his various compositions ;—his domestic habits;—contemplates the establishment of a school of natural history ;—his paper on the heat of animals and vegetables;—is appointed surgeon extraordinary to the King;—his paper on the recovery of drowned persons ;— Croonian lectures;—correspondence;—is attacked with an alarming illness, attended with peculiar symptoms;—his visit to Bath;—his character as an experimentalist;—his second part on the teeth;—his expenses and difficulties ............37 CHAPTER V.

Mr. Hunter's paper on the hermaphrodite black cattle;—his anxiety for rare specimens to enrich his museum;—renewal of the disagreement between him and his brother.—Mr. Hunter's paper on small-pox during pregnancy;—his paper on the hen pheasant.—Trial of Sir T. Boughton.—Croonian lectures.__ His paper on the organ of hearing in fishes;—removes to Leicester square ;__ assists in forming the Society for the Improvement of Medical and Chirurgical Knowledge.—Charlatanism.—Correspondence.—Mr. Hunter's notion of the immateriality of matter from the theory of colours;—his paper on the inflammation of veins;—his fame and practice at this time;—his merits as an operating surgeon;—his illness returns ;—his second visit to Bath;—Mr. Home acts as his assistant.—Mr. Hunter's paper on the double-coned Terebella;__his operation for popliteal aneurism;—is appointed Deputy Surgeon-general to the Army;—his Treatise on the Venereal Disease;—his work on the Animal QSconomy;—prints his own works at his own house ;—his paper on the Wolf CONTENTS. 7 Jackal, and Dog ;—his paper on Whales—The giant O'Brien__Obtains the Copley medal;—opens his museum to the public—Mr. Home and Mr. Keate appointed assistant surgeons at St. George's Hospital.—Sits for his portrait to Sir Joshua Reynolds.—Sharpe's engraving.—Death of Pott;—comparison between him and Hunter__Pott's character . .57 CHAPTER VI.

Mr. Hunter's high station in the profession at this period ;—anecdote of his early rising—Mr. Thomas.—Sir A. Carlisle—Mr. Lynn.—Instance of Mr. Hunter's generosity ;—stands godfather to Dr. Jenner's first child ;—his paper on intussusception ;—his paper on paralysis of the oesophagus.—Mr. Home's paper on the formation of loose cartilages—White's New South Wales__Mr. Hunter's illness ;—his violence of temper ;—his style of living;—his fondness for bees ; —his Tory politics—Funeral of Sir Joshua Reynolds. Mr. Hunter's paper on bees ;—his letter to Sir Joseph Banks on this subject;—his surgical lectures ; —his work on the Blood and Inflammation.—Veterinary College established.— Mr. Hunter's disagreement with his colleagues at St. George's Hospital;—his death, and character as a private man and as a philosopher;—his will and effects —the purchase of his museum.—Correspondence between Lord Auckland and Sir Joseph Banks on this subject.—The terms on which this purchase was finally made.—Rebuilding of the College of Surgeons ... 82 CHAPTER VII. The Hunterian Museum.........102 Appendix 130 INTRODUCTION TO THE LIFE. Besides several brief memoirs of John Hunter which have appeared in various works of general biography, his life has already been written at considerable lensrth bv three different authors. Neither of these publications, however, furnishes us with more than a very imperfect account of his character, either as a private individual or as a Natural Philosopher. The memoir by Sir Everard Home, prefixed to the work on Inflammation, is a scanty outline, almost wholly devoid of those characteristic anecdotes which form so essential a part of biography, and which his near connexion with Mr. Hunter would have enabled him to introduce; whilst nearly a third part of the whole is occupied with a detailed account of his various illnesses. The memoirs by Dr. Adams, and Mr. Jesse Foot, stand in singular contrast to each other, the former displaying everywhere marks of indiscriminate and unbounded partiality towards Mr. Hunter, the latter of bitter hostility, leading to the most flagrant misrepresentations of facts. It appeared, therefore, if not necessary, at least appropiate and desirable, to prefix to this new and revised edition of his writings, a full and impartial account of this eminent man. It is known to most of those who have kindly furnished information for this work, that Mr. Palmer did at first intend himself to have^ undertaken the office of Mr. Hunter's biographer; and he feels that some apology is due to those from whom he received communications under this supposition, for transferring the task to another. A want of sufficient time to execute the task was the chief, if not the only reason, for his declining to fulfil his intention; and it was only when satisfied that such was the fact, that I consented to engage in an undertaking which I should gladly have seen continued in more able hands. In fulfilling the charge with which J have been entrusted, 1 have endeavoured to avail myself of all the information respecting Mr. Hunter to be found in preceding publications ; nor have I scrupled to adopt the opinions of others regarding him where I thought them correct. 3 10 INTRODUCTION. In addition to the materials gathered from these sources, I have been enabled to enrich this memoir with the whole of the letters written by Mr. Hunter to Dr. Jenner, during a friendship of more than twenty years' duration. The originals of these, many of which have already appeared in Dr. Baron's Life of Jenner, were liberally communicated to Mr. Palmer by Robert Fitzhardinge Jenner, Esq., of Berkeley. The letters of Hunter to Sir Joseph Banks, as well as the interesting correspondence between the latter and Lord Auckland, respecting the Museum, were obtained through the kind intervention of Dawson Turner, Esq., of Yarmouth, to whom were entrusted the whole of Sir Joseph Bank's papers, by his executor, Sir Edward Knatchbull. During the time that Mr. Palmer contemplated writing this life himself, he was at the pains to gather as much general information, and as many authentic anecdotes as possible, respecting the subject of this memoir, from his surviving friends and pupils. Of these anecdotes, many of which are highly characteristic, I have introduced by far the greater number; some which I have inserted may be thought so trivial as scarcely to have merited notice, but I have preferred rather to risk having this laid to my charge than to omit anything that might serve to illustrate Hunter's real character. It will be seen from what I have said that my duty has been greatly lightened by having the already accumulated materials placed at my disposal; in addition to this I have to acknowledge the receipt of many valuable suggestions from my friend Mr. Palmer, respecting the various parts of the work,—suggestions from which I have rarelydissented, but which have often madexne regret that circumstances prevented his being able himself to carry them into execution. How far I may have satisfactorily accomplished what I have undertaken, is not for me to judge, I will not pretend to indifference respecting the judgment that others may come to on the point; on the contrary, it would afford me much satisfaction to feel that my time had not been uselessly employed, but that I had succeeded in furnishing, what has been hitherto a desideratum in medical literature, a full and faithful account of the life of John Hunter. DREWRY OTTLEY. Exeter, March 3d, 1835. THE LIFE OF JOHN HUNTER, F.R.S. CHAPTER I.

Mr. Hunter's birth and family;—his early habits.—Dr. Wm. Hunter's rise to fame;—his difficulties at the outset of life.—Mr. Hunter's arrival in London ; —his rapid acquisition of anatomical knowledge ;—becomes a pupil of Cheselden.—Cheselden's mode of operating for stone;—his character and death.— Mr. Hunter's employments at this period ;—the advantages which he derives from his brother's society. %_ Johx Hunter was born at Long Calderwood, a small estate belonging to his family, situated about eight miles from Glasgow, in the parish of Kilbride East, Lanarkshire. His father, who appears to have been a small farmer living on his own estate,^was descended from the ancient family of Hunter of Hunterston, a part of which property they had received from Robert the Second. His mother, whose maiden name was Paul, was the daughter of a respectable citizen of Glasgow, who held the office of Treasurer of that place. John, the youngest of ten children, was born in the year 1728, but on what day is not exactly known : the parish register states the 13th of February to have been his birthday, but he himself used to date it on the day following, and it is on the 14th, consequently, that his anniversary is celebrated at the College of Surgeons. We have no means of knowing whether either of his parents displayed any remarkable degree of talent, but it is certain that their offspring, both in the first and second generation, included an unusual number of persons eminent for their intellectual superiority.* Besides William, of whom mention will often be made in

* Mr. Wardrop, in his interesting life of Dr. Baillie, observes, that " the extent of talent united in his family and connexions was remarkable. He was not only the son of an able Professor, and nephew of the two Hunters, but his sister, Miss Joanna Baillie, has attained the most elevated rank in literature. Mrs. Baillie's 12 THE LIFE OF JOHN HUNTER. the course of these memoirs, another brother, James, the eldest of the family, possessed considerable abilities. He was intended lor the Law,'and completed his studies with a view to practising as a writer to the Signet in Edinburgh; but on visiting London in his twenty-seventh year, he became so enamoured of the pursuits in which he found "his brother William engaged, that he determined on devoting himself thenceforward to Physic. He immediately began the study of anatomy, and pursued it with such zeal and dilligence, as speedily to attain considerable proficiency; added to this he was possessed of peculiarly engaging manners, and displayed talents which, in Dr. Hunter's opinion, could not have failed to place him in the highest rank as a professional man in London. He was, however, attacked with a spitting of blood, which obliged him to relinquish his pursuits and return to his native place; but the change proved of no avail, his complaint increased, and in no long time proved fatal. One of the daughters, Dorothea, was married to Dr. James Baillie, Professor of Divinity in the University of Glasgow, and gave birth to the late Dr. Baillie, author of the ' Morbid Anatomy,' and for many years the first physician in London; and to Mrs. Joanna Baillie, the highly gifted authoress of the Dramas on the Passions. Agnes, another daughter, married Mr. Buchanan, a cabinet-maker of Glasgow. The other children all died young. Hunter's father died in 1738, at the age of 78, and John was thus left, at ten years of age, to the care of a fond, and apparently over-indulgent mother: the consequence was, that being in a great measure master of hft own actions, and having little taste for books, he preferred engaging in country sports, to studying those elementary branches of knowledge which are best acquired in youth, and the want of which, as in the case before us, is sure to be severely felt in after-life. When Hunter was about seventeen, he went to stay for a time at the house of his brother-in-law, Mr. Buchanan, under the hope of being able to assist in freeing him from the pecuniary difficulties into which his convivial habits and inattention to business had led him. It is probable that whilst here, Hunter, who prided himself on his manual dexterity, assisted his brother-in-law in his workshop, and that hence originated the statement made by Foot, that he had served as a millwright or a carpenter. His efforts, however, proved unavailing to accomplish the object of his visit, and Mr. Buchanan soon after resigned his business, and earned a scantv livelihood as a teacher of music, and clerk to an Episcopalian chapel in Glasgow.

sister was married to the late Sir Richard Croft, a man whose name is endeared in the recollection of many, as well for his manly and upright heart as for his professional celebrity : and Mr. Denman, who has distinguished himself so much at the bar, (now Lord Chief Justice), was Dr. Baillie's brother-in-law." Of this tendency of genius to display itself in various members of the same family, many remarkable examples might be adduced from ancient as well as modern history. THE LIFE OF JOHN HUNTER. 13 During this time.Wm. Hunter was rapidly pursuing his way to fame and fortune. After receiving a classic education at Glasgow University, and studying medicine for three years as a pupil of Cullen, who was at that time practising at Hamilton, he resorted to Edinburgh, where he spent a winter attending the schools of anatomy and medicine, and finally settled in London in 1741. He was immediately engaged by Dr. Douglas to assist him in making preparations for a work on the bones, and also to take charge of the education of his son. With these views, accordingly, he became an inmate of the family ; but on the death of Douglas, in the following year, he turned his thoughts to lecturing on anatomy, and immediately set about making preparations on a large scale for the purpose. In 1745 a fair opening for his exertions offered, on the resignation of Wm. Sharpe, who had for several years past given a course of lectures on surgery, which he had undertaken at the express request of a number of naval surgeons. To this class Wm. Hunter succeeded, and after a time altered the plan of the lectures so as to render his course much more of an anatomical than of a surgical nature.* Previously to this time, Wm. Hunter's means had been very limited, for though the family property had fallen to him at his brother James's death, yet as his mother continued, with his permission, to reside on the estate, the surplus accruing to him could have been but small, In proof of this, Mr. Watson, formerly surgeon to the Westminster Hospital, and one ofWm. Hunter's earliest pupils, used to relate, that as they were walking home together after the introductory lecture, the latter, who carried a bag containing seventy guineas, which he had received for entrance fees, remarked, that this was a larger sum than he had ever before been possessed of. Linnasus gives a similar account, of his own slender beginnings where he says, "Exivi patria, triginti sex nummis aureis dives;" and it is related by Sir James Earle, that at Pott's death, a small box was found among his papers, containing a few pieces of money, not amounting to five pounds, being the whole which he ever received from the wreck of his father's fortune. Such anecdotes may serve to encourage those who, at the outset of their journey through life, chance to have their purses but slenderly furnished: numbers more might be found by a reference to the lives of eminent men in all professions, many of whom, though they have afterwards

* It was customary for the lecturers of that day to treat in one course on a number of subjects, sufficient to furnish matter for three or four distinct courses according to our present system ; and the meagre amount of information afforded to their hearers may be judged of by the following facts, mentioned by Mr. Chevalier in his Hunterian Oration. Mr. Bromfield, who was suifeeon to St. George's, and a lecturer of considerable note, comprised anatomy and surgery in a course of thirty-six lectures. Dr. Nicholls, at whose school Wm. Hunter studied, professed to teach anatomy, physiology, and the general principles ot pathology and midwifery in thirty-nine, and Mr. Nourse of St. Bartholomew s embraced "totam rem anatomicam" in twenty-three lectures. 14 THE LIFE OF JOHN HUNTER. reaped a bountiful share of the favours of Fortune, were doubtless obliged, on their first starting in life, to have recourse to shifts quite as curious as those of Johnson's Irish friend, who in describing how a man may live respectably in London on thirty pounds a year, allots ten for the expenses of clothes, and provides that all visits are to be paid on clean shirt days. Wm. Hunter had many difficulties to overcome in establishing his anatomical school; he was the first surgeon, unconnected with a hospital, who had lectured on anatomy,* and no one had attempted it on a scale at all equal to what he proposed: his predecessors had been accustomed to employ but one subject for demonstrating all parts of the body, excepting the bones and arteries, which were described on preparations; and the nerves, for exhibiting which a foetus was usually employed. Practical dissection was " unknown to the great bulk of the profession. Added to all this, a \ far greater horror of anatomical pursuits existed in the public mind '' at that time than at the present. William Hunter's address and perseverance at length triumphed over all these difficulties, and he succeeded in forming an establishment, which, in consequence of the superior advantages it afforded, and the unrivalled talent of its founder as a lecturer, for a long time maintained its rank as by far the first anatomical school in London. John Hunter was now in his twentieth year, when the fame of his brother's success made him desirous of entering into the same profession. He accordingly wrote to his brother, requesting to be allowed to join him in London, and offering his services as an assistant in the dissecting-room. The reply was favourable, and contained a kind invitation to visit London. He lost no time in complying with this, but set out on horseback in September, in company with Mr. Hamilton, a friend of the family, and arrived at his brother's house about a fortnight before the commencement of the autumnal course of lectures. No long time elapsed before

* It was not until 1745 that the alliance between barbers and surgeons was happily dissolved : before this time, any surgeon dissecting a body out of their Hall was liable to a fine of ten pounds. Amongst other privileges, they possessed the right of claiming annually the bodies of four executed felons, which probably led Dr. Caius to choose the Barber-Surgeons' Hall, to deliver his anatomical lectures in, soon after their incorporation in 1540. From this time to the dissolution of the company, their readers of anatomy were, with very few exceptions, chosen from the College of Physicians, to whom, with the exception of Cowperand Cheselden, is due the merit of supporting the fame of this country in anatomical pursuits, from the time of Caius to that of the Hunters. In the list of physicians who successively taught anatomy in England, we find the names of Caius, Harvey, Glisson, Mead, Willis, Lower, Wm. Hunter, and last, though not least, qf Matthew Baillie. With Dr. Baillie ended the race of Physician-. Anatomists, with the exception of Dr. Wilson, who lectures at the present day. This resignation of the professor's chair of anatomy on the part of the physicians! arose not however from any lack of able men to fill it, but from a conviction that the surgeons were now fully capable of instructing their own pupils, and with more practical effect. THE LIFE OF JOHN HUNTER. 15 John's skill was put to the trial in preparing for the lecture a dissection of the muscles of the arm. It is. probable that Wm. Hunter had not as yet formed a very high estimate of the talents of his hitherto idle brother, and little foresaw that he was ere long to eclipse his preceptor: he was, however, so well pleased with his pupil's first essay, that he soon after entrusted him with the preparation of a similar part, of which the blood-vessels were injected. In this the young student again succeeded so well as to obtain much praise for his dexterity from his brother, who foretold that he would soon become a good anatomist, and promised that he should never want employment. From this time, therefore, we may consider. Hunter as engaged in the dissecting-room, under the instruction of his brother's assistant, Mr. Symonds, where he pursued his studies with such zeal and diligence that by the next season he was able to take the charge of directing the pupils in their dissections ;—thus, by his rapid progress, showing what ma}7 be effected by great diligence, and adding another to the examples furnished by Cheselden, Haller, Albinus, Baillie, Abernethy, and a host of others, that the surest foundation for future professional eminence is an early and extensive knowledge of anatomy. The summer after he arrived in town, Wm. Hunter obtained permission for his brother to attend at the Chelsea Hospital, under Cheselden, of whom, as Hunter's first master in surgery, and as the most celebrated surgeon of his day, no apology will be necessary for introducing a short account. This admirable surgeon was now more than sixty years of age, and had retired in great part from the toils of a profession in which he had been engaged during nearly forty years, and in which he had attained the highest rank. As a surgeon, Cheselden may be said to have enjoyed the same repute, both in England and on the Continent, which his contemporary and friend Dr. Mead had acquired as a physician. He was educated at St. Thomas's Hospital, under Mr. Feme, a very able man, and studied anatomy under the celebrated Cowper. At twenty-two he became a lecturer on surgery and anatomy, and in the following year was elected a member of the Royal Society, to whose Transactions he contributed several papers, the most remarkable of which contained the description of the operatipn by which he restored to sight a lad who had been blind nearly from birth. At Feme's death he was elected first surgeon to St. Thomas's, and was appointed consulting surgeon to St. George's and the Westminster Hospitals. He was eminent in every department of surgery, but it was as a lithotomist that his name first became known all over Europe. The operation he at first adopted was that called the high method, when the bladder is entered above the pubes, which be performed with considerable success, saving six out of every seven who were cut. About this period, however, all Europe rang with the name of Raw, the famous Dutch lithotomist, who had adopted Frere Jacques's method, with improvements of his own, but kept his plan so profound a secret 16 THE LIFE OF JOHN HUNTER. as to blind the eyes even of the famous Albinus, his assistant, as to the exact parts through which he cut. Cheselden, with Douglas, and other surgeons in London, who had met with less success by the high method, tried the mode described as Raw's by Albinus, in which the whole wound in the bladder was made beyond the prostate; but they experienced such ill fortune that they felt assured the operation was not correctly described, and Cheselden, abandoning this, planned the lateral operation as it is at present performed. He now met with such signal success, that Morand, then one of the first surgeons in Paris, came over to this country purposely to learn the operation, and during his stay saw Cheselden cut twentyseven patients without losing one. Cheselden's manners were exceedingly kind and gentle, and notwithstanding the extensive practice he had enjoyed, he always, before an operation, felt sick at the thoughts of the pain he was about to inflict; though during its performance his coolness and presence of mind never forsook him.* In alluding to this feeling, Morand relates an anecdote of a French surgeon who, on visiting the Hospital, expressed great surprise at witnessing such an evidence of weakness, as he considered it, on the part of so famous a surgeon: after the operation was over, the visitor was invited by Cheselden to accompany him to the fencing school, whither he was going to see a sparring match; but here the tables were completely turned, for no sooner did the contest begin, than the stranger turned pale at the sight, and was obliged speedily to betake himself to the open air. It was under this great man that Hunter received his first lessons in surgery,—a worthy master for so eminent a pupil; and he continued to attend regularly at the Chelsea Hospital during the summer months of 1749 and 1750. Here he would have probably continued for some time longer, but in the following year Cheselden was obliged to resign his situation in consequence of an attack of paralysis, which entirely unfitted him for business. He repaired to Bath in the hope of amendment, but in 1752 he was seized with apoplexy, which put an end to his life, in the sixty-fourth year of his age. Besides his talents as a surgeon, Cheselden displayed considerable taste in the fine arts ; he was fond of poetry, and an intimate friend of Pope; he had also made architecture his study, and it was from his plans that Putney Bridge, and the former Surgeons' Hall in the Old Bailey were erected. But to return to Hunter. We may consider him as now fully entered on his professional studies; and as he was not one who ever loitered over an undertaking, it is probable that his time was pretty fully occupied between the hospital and the dissectino--room. He was, however, fond of company, and as he had not, like Haller, forsworn the use of wine on commencing his medical studies, though he found it necessary to do so in after life, he mixed much *Such feelings, in a less marked degree perhaps, are far more commonly experienced than i9 generally supposed, by the very best surgeons previously to undertaking operations of importance. THE LIFE OF JOHN HUNTER. 17 in the society of young men of his own standing, and joined in that sort of dissipation which men at his age, and freed from restraint, are but too apt to indulge in. Here, as in graver matters, his ambition urged him to take the lead of his companions, amongst whom he went by the familiar title of " Jack Hunter." Nor was he always very nice in the choice of his associates, but sometimes sought entertainment in the coarse broad humour to be found amid the lower ranks of society. He was employed by his brother to - cater for the dissecting-room ; in the course of which employment he became a great favourite with that certainly not too respectable class of persons the resurrection men ; and one of the amusements in which he took especial pleasure, was to mingle with the gods in the shilling gallery* for the purpose of assisting to damn the productions of unhappy authors, an office in which he is said to have displayed peculiar tact and vigour. It must not, however, be supposed that it was to company like this, or to the society of wild young men, that Hunter was confined. His brother was a scholar, and possessed of gentlemanly manners, and though comparatively a stranger in London, he was already known as a man of much talent, and as likely to rise to eminence; he was also fond of society, and his house was consequently frequented by many of the first men, not only in his^own but in other professions. It has therefore seldom fallen to the lot of young men to enjoy equal opportunities of cultivating their minds by association with men of talent; and though there can be no question that by far the greater part of his future eminence was owing to the • original powers of his mind, yet, in recording the history of his life, it will be proper to trace the means by which those powers were improved, and to show, as far as may be, the assistance he received in bringing them fully into action. It is the more necessary to do this, in order to correct an unfounded opinion which generally prevails, that Hunter should be classed with those untaught geniuses who have risen to the highest honours by their own unaided powers. This was evidently not the case, and the meagreness of his early history seems sufficiently to prove that it was at his brother's table, and in his brother's dissecting-room, that his ambition and his talents were first roused to activity: without such a stimulus his genius might have slumbered, or have taken a wrong direction. Nor does this detract from his real merit. There is perhaps nothing that more distinguishes the man of genius than the manner in which he turns to account the advantages which common minds would let slip without profit. Hunter was a man of extraordinary powers; he was placed in circumstances the best fitted to excite these powers, and give them their full effect, and the result was such as could only have been produced by this fortunate combination of circumstances. 4 18 THE LIFE OF JOHN HUNTER. CHAPTER II.

Hunter becomes a pupil of Pott.—Pott's character as a Surgeon.—Hunter enters at St. Mary's Hall, Oxford ;—enters as a pupil at St. George's Hospital ;— discovers the mode of connexion between the placenta and uterus;—his conduct as a lecturer and demonstrator of anatomy.—Disputes of the Hunters with contemporaneous anatomists respecting the anatomy of the testes, the office of the lymphatics, and the hernia congenita.—Hunter traces the nerves of the nose;—his experiments on the subject of venous absorption ;—commences the pursuit of comparative anatomy ;—embarksfor Belleisle;—is still ardent in the pursuit of science.—Jesse Foot and his Life of Hunter.

On the retirement of Cheselden from the Chelsea Hospital, Hunter entered as a surgeon's pupil at St. Bartholomew's. To this hospital Pott had been elected surgeon about two years before, after having served as assistant from 1745. He was now in his thirtyeighth year, and was fast rising in reputation as a most able practical surgeon. As an author he was not yet known, for his first work of importance, the '• Treatise on Ruptures," which was composed during his confinement with a compound fracture of the leg, did not appear until 1756. Nor had he at this time commenced the delivery of his surgical lectures. At the hospital, however, Hunter must have acquired many a useful lesson, from a comparison of the lenient practice of leaving tnuch to the efforts of nature, which Pott's sound judgment had led him to adopt, with the rude and pernicious interference with these efforts, which Nourse and his other colleagues, according to the custom of their day, were in the habit of employing. Surgery was at this time beginning fast to emerge from the state of barbarism in which it had long existed. To this change the French Academy of Surgery greatly contributed, and they have left us, in their Memoirs, a fine example of men laying aside petty jealousies and uniting their powers for one common object,—the advancement of their common profession. It was in the operative parts of surgery, as might be expected, * that the chief improvements were first made, a result almost necessarily arising from the knowledge of anatomy becoming more diffused. Far less had been done towards simplifying the curative department. The actual cauteries and charcoal-pan were still considered an essential part of the dressing apparatus at the hospital, and a farrago of applications, going under the names of suppuratives, digestives, and sarcotics, were implicitly relied on for effecting those changes which Nature was all the while performing in spite of her injudicious allies. Pott was the first surgeon in this country who successfully attacked these abuses, and, as usually falls to the lot of innovators, THE LIFE OF JOHN HUNTER. 19 was laughed at by his colleagues for his attempts. Several of the improvements suggested by him were, no doubt, introduced after the time when Hunter was a student; yet we may fairly suppose that the latter obtained many useful hints from those he witnessed, which, confirmed and improved on during his practice in the army, may have formed the basis of some of the philosophic views which we owe to his genius. At this hospital Hunter attended regularly during the summer months of 1751, and occasionally in the winter, when any operation of importance was to be performed. During the next summer he was absent from town, on a visit to Scotland, whither he went, partly probably to enjoy some relaxation from his labours, but principally for the purpose of accompanying to London his sister, Mrs. Buchanan, whose husband had died not long before. In 1753 Hunter entered as Gentleman Commoner at St. Mary's Hall, Oxford. Neither of his biographers satisfactorily explains the motives which led him to take this step, but it seems probable that he was persuaded to it by his brother. It was not yet decided what line of practice John should pursue, and if there were thoughts of his becoming a physician, as it seems there were, it was natural that William, who was a good classic, and valued literary attainments, should recommend his brother to devote some time to the cultivation of those branches of knowledge, which he had hitherto so entirelv neglected. He was also recommended, it would seem, to try his"fortune as an accoucheur; but neither this proposal nor the former was to his liking, and he eventually decided on confining himself to the practice of surgery. In speaking of this period of his life some years afterwards to Sir Anthony Carlisle, then a student at the hospital, Hunter said: " They wanted to make an old woman of me; or that I should stuff' Latin and Greek at the University; but," added he, significantly pressing his thumb-nail on the table," these schemes I cracked like so many vermin as they came before me." It was fortunate, probably, that he decided as he did, for though his future progress was slow, the roughness of his manners would have been a still greater impediment to him in either of the other branches of the profession. Having determined, then, on adhering to the practice of surgery, Hunter naturally felt anxious to secure for himself a chance of election at some future day to one of the London hospitals. His prospect of obtaining the situation of surgeon to the Chelsea was too uncertain and too remote to be calculated on; and at St. Bartholomew's it would have been necessary for him to serve an apprenticeship of five years to one of the surgeons, which, at his age, and with his occupations, was quite out of the question. Fortunately, no such obstacle offered at St. George's, where he accordingly entered as surgeon's pupil in 1754, and attended, as in the former instances, during the summer months, whilst the winter was devoted to his duties and studies in the dissecting-room. Two years after this he served the office of house-surgeon to the hospi. 20 THE LIFE OF JOHN HUNTER. tal, a most desirable post for a young man intending to enter on surgical practice, since, in addition to the immediate care of all the patients under the direction of the surgeons, in their absence, a a great part of the treatment of fractures, and several of the minor operations of surgery, usually devolve upon this officer. Hunter's extensive acquaintance with anatomy was now generally known and appreciated, and he was not unfrequently applied to by others to assist them in clearing up any difficulties they might encounter in their researches. It was on an occasion ot this kind, and about this time, that the important discovery of the mode of connexion between the placenta and the uterus was made. The honour of solving this anatomical problem was laid claim to by each of the Hunters, and the dispute to which it gave rise twentyfive years afterwards caused a breach between them that was never healed until William was on his death-bed ; and scarcely, it would seem, in his mind, even then. The following is the account which John Hunter has given of the transaction in his work on the " Animal CEconomy." In May 1754, Dr. Mackenzie, then an assistant with Dr. Smellie, had been particularly successful in injecting the arteries and veins of the uterus, in a woman who had died during pregnancy. The appearance being new, he applied to Hunter for his assistance in making the examination, who, after having dissected and made the whole into preparations, on his return home in the evening communicated what had been done to Dr. Hunter. The latter treated his brother's account at first with good-natured raillery, but on seeing the parts was soon convinced of the truth of the statement. Some of the portions were given to the Doctor, who afterwards exhibited them at his lectures: but in what manner he mentioned the subject, or what credit he gave to John on these occasions, does not appear. In his work on the gravid uterus, published in 1774, he gives general acknowledgments to his brother for his assistance, but does not mention his name in connexion with this particular subject. As it will be necessary to recur briefly to this dispute at a latter period, no more need be said at present, except to remark, that attempts have been recently made to show that this discovery, on which so high a value was set at the time, is in truth not a discovery, but an erroneous opinion. The most distinguished anatomists and physiologists of the present day, on the Continent, take this view of the subject; still, the doctrine of the Hunters is supported by evidence too strong to be easily overset, and it is said that some recent minute dissections instituted by Mr. Owen, which have not yet been made public, still further confirm the truth of their opinion. In the course of this year Hunter became a partner with his brother in the anatomical school, and a portion of the lectures was regularly allotted to him; besides which, he took his brother's station whenever he was unavoidably absent. The lecture-room was not, however, a place in which John Hunter was calculated to shine, THE LIFE OF JOHN HUNTER. 21 as he had always great difficulty in delivering himself extempore, an acquirement almost indispensable in anatomical teaching. Hence, notwithstanding his extensive and accurate knowledge of anatomy, he never gained a popular manner, and could not but have appeared to great disadvantage when contrasted with the Doctor, who was so pre-eminently qualified as a teacher. In the dissecting-room he felt himself more at home, and it was here that he spent all his leisure hours, in making preparations, and in pushing his inquiries in anatomy and physiology beyond the point which his predecessors had attained. Since the time of Vesalius anatomy had been prosecuted with great zeal and success by eminent men, both in England and on the Continent, and the most important parts of the human body had been more or less accurately described. There still remained, however, many minor parts, the structure of which had not been fully made out, and the newly discovered system of the lymphatics was as yet but imperfectly known. The invention of various modes of injecting the vessels had of late greatly facilitated researches into the minute structure of parts. Many able anatomists in the various schools of Europe were ardently engaged in pursuing such researches, and by none were they carried on with more zeal than by the Hunters. A natural consequence of this direction of many minds to one object was, that a new discovery was frequently made nearly at the same time by different inquirers, and it became difficult to ap* portion the degree of credit due to each. The eagerness of the claimants for honour often led to disputes, in which far more warmth was displayed than the point in question merited, so that on reading the annals of these paper wars, we cannot but feel surprise at the violence shown abo«t matters of such little mo-. ment. Dr. Hunter himself was a very Achilles in this sort of warfare.

Impiger, iracundus, inexorabilis, acer.

Jealous of his supposed rights, and unwilling to admit the possibility of a discovery occurring to two independent inquirers, he was far too apt to accuse his antagonists of plunder if they displayed as their own any of those anatomical trophies to which he could establish a prior claim. In several of his encounters, tlie discoveries which gave rise to them were due in great part to John, who, being far more dexterous with the scalpel than the pen, left the defence of their common property to William, whose literary attainments better fitted him for the service, and who displayed considerable ability in its per^ formance. Two of these disputes were with the Munros: the one, as to the first successful injection of the tubuli testis with mercury; the other, as to the discovery of the true office of the lymphatics. In both cases Dr, 4* 22 THE LIFE OF JOHN HUNTER. Hunter fairly showed that he had taken the lead of the Munros. On the former question, indeed, he had been, to a certain extent, forestalled by Watson and by Haller; but on the latter, though other physiologists may have somewhat earlier suggested that the lymphatics were probably absorbents, the merit of proving this by observation and experiment, and of pointing out the great importance of these vessels in the animal ceconomy, is undoubtedly chiefly due to William and John Hunter. The third encounter was with Pott, who was no favourite with the Scotch faction in London, of which William Hunter was a leading member. He accused Pott of stealing from himself and his brother the knowledge of the true nature of hernia congenita, without acknowledging it in the paper he published on the subject. Pott, however, denied the accusation, and we have no reason to doubt his veracity. Be this as it may, both had been anticipated by Haller, who had a year or two before explained the nature of the disease, and given it the name of congenital hernia. There was a question, however, connected with this latter subject which required to be cleared up, namely as to the cause and mode of descent of the testis in the foetus. The explanation of the process given by Haller and Pott was fanciful and unsatisfactory; and to John Hunter alone is due the merit of explaining the steps of this curious physiological problem in so full a manner as to leave nothing to be added by others on the subject. The details of this inquiry, which gained him great credit, were first published in Dr. Hunter's Commentaries, and are given more at length in John Hunter's valuable work on the Animal (Economy. In addition to the above researches, he about this time traced the ramifications of the first pair of nerves within the nose; and from his preparations the engravings were executed which he published in the Animal (Economy, accompanied by some valuable physiological remarks on the nervous system generally. In 1758, and the following year, he instituted a set of experiments, which are detailed in Dr. Hunter's Medical Commentaries, for the purpose of ascertaining whether veins possess the power of absorbing. These were ingeniously contrived, and, to the minds of all present, so satisfactorily decided the question in the negative, that they greatly contributed to confirm the opinion that absorption was carried on by the lymphatics and lacteals only, and apparently gave the death-blow to the ancient doctrine of absorption by veins. Here again, however, later physiologists, by new and more varied inquiries, have succeeded in throwing considerable doubts on the correctness of Hunter's inferences, and have brought forward evidence, which, if not decisive, yet affords strong ground for believing that the veins are to a certain extent absorbents. What are the relative parts taken by these two sets of vessels in carrying on this function, or whether the apparent absorption by veins is not a mere effect of simple imbibition, still remains to be discovered. It was one time Hunter's intention to have made a series of pre- THE LIFE OF JOHN HUNTER. 23 parations of the whole system of lymphatics, and to have published engravings of them. With this view he had completed a preparation of the lymphatics of the lower extremity, from which Rymsdyk had executed a drawing; but ill health, and a variety of occupations, prevented his carrying the plan into effect. Hunter had now been ten years engaged in the study of human anatomy, and having found that there were many parts the structure and functions of which required to be elucidated by a reference to other sources, he began with the same diligence to pursue his researches in the wide field of comparative anatomy. His health, however, was beginning to suffer seriously from his incessant labours. In the spring of 1759 he was attacked with inflammation of the lungs, which left behind it symptoms that threatened to end in consumption. He was strongly advised, therefore, to leave London for a time, and seek a more southerly climate. With this view he applied for an appointment in the army, and was immediately made Staff-Surgeon by Adair, who was then Inspector-General of Hospitals. Europe was at this time engaged in the seven years' war, one of the most sanguinary of those in which nations were formerly so often involved, by their mutual jealousies, or the ambition of their rulers. England was, as usual, amongst the foremost in the contest, and early in 1761, a powerful armament was sent from this country under General Hodgson and Commodore Kepple, to lay siege to Belleisle, an island off the western coast of France. With this armament Hunter embarked ; and as the siege, though short, was extremely sanguinary, he was at once furnished with ample opportunities for practice in the treatment of gun-shot wounds. By the following year England had embroiled herself with Spain. British troops were sent out for the protection of our Portuguese allies, and with these Hunter proceeded to the Peninsula. Here he remained on active duty until the end of the year, when all parties being heartily tired of the contest, the preliminaries of peace were agreed on. Notwithstanding his constant employment in the practical duties of his profession whilst with the army, Hunter found time to pursue those physiological researches in which he took supreme delight. He made several experiments on lizards and snakes, to ascertan whether digestion continues during their torpid state; and he was also engaged in some inquiries on the faculty of hearing in fishes. It was during these campaigns, too, that most of his observations on gun-shot wounds were made, and that many of the peculiar views which his work on inflammation unfolds, first suggested themselves to his mind, though they were not published until more than thirty years afterwards, as he constantly endeavoured during his whole life to confirm and amend them, and to build ' them up into a work on which his future fame should depend. We have no authentic account of Hunter's private life during the time he was with the army. Jesse Foot accuses him of exciting 24 THE LIFE OF JOHN HUNTER. jealousies and quarrels amongst his colleagues; but to Foot s statements no sort of credit is due. He wrote what he is pleased to call the Life of Hunter with the same view that he made all his other attacks on him, under the hope, namely, that he might succeed in dividing the town into two parties, and himself become the Magnus Apollo of one of them. His hope of rivaling Hunter was certainly sufficiently ridiculous, and it need hardly be added that he utterly failed in his aim. Whether he carried his abuse so lar as to disgust those he wished to please, or that his talents were not equal to filling a high station, certain it is he never made much figure in his profession; and whilst Hunter's name and works have been year after year rising into higher and still higher esteem, those of his traducer, Foot, are already well nigh buried in merited oblivion.* , u In the spring of 1763, peace having been proclamed, Hunter accompanied the forces home, and on arriving in England immediately returned to the metropolis.

* When Hunter published his work on the Venereal Disease, Foot followed with a book of his own on the same subject, filled with abuse of the doctrine and practice of his predecessor. Hunter was too wise to give consequence to his petty foe by publicly replying to his attacks, but the following comments were written by him on a couple of scraps of paper, destined for pipe-eights, but rescued from the flames by Mr. Clift. » One may say of Jesse Foot as we say sometimes of young men, < It was well their fathers were born before ^them. It was well for Jesse Foot that I published my book before he wrote his." " Jesse Foot accuses me of not understanding the dead languages; but I could teach him that on the dead body which he never knew in any language dead or living. Foot's best work was the life of his relative Murphy, the translator of Tacitus; but by an unfortunate blunder in the motto prefixed, he has betrayed how little pretence he, at least, had for reproaching Hunter with his want of classical knowledge. This motto he solicited and obtained from Mr. Thomas Copeland of Golden Square, a gentleman as distinguished in his profession as he is for true taste in classic literature ; but by an absurd mistake Foot perverted its meaning, and thereby entirely destroyed its beauty. The following is the motto as it stands in his work. " Non hoc prsecipuum amicorum munus est, prosequi defunctum ignavo quaestu, sed quae voluerit meminisse, quae mandaverit exsequi." Tacit. Jinn. lib. ii. By substituting quaestu for questu, as in the original, he has spoiled an elegant motto. It is said that Foot received four hundred pounds from some of Hunter's enemies for writing his life ; if so, he deserves only to be remembered in connexion with a homely remark of Hunter's, in answer to a gentleman who was condemning this sort of conduct, " O, sir ! we all have vermin that live on us." THE LIFE OF JOHN HUNTER. 25 CHAPTER III.

Hunter settles in London.—Alienation between the brothers.—His straitened circumstances ;—his favourable position in othej. respects.—Patience and fortitude required of young surgeons.—Obstacles to Hunter's success;—his contempt of humbug;—his thirst for fame and knowledge greater than his love of wealth ;—delivers lectures on anatomy ;—his persevering industry— The state of surgery at this period.—The plan of his vast future labours conceived and entered upon.—The Baconian philosophy.—Earl's Court.—His encounter with a bull and two leopards ;—is made F.R.S.—His description of the Proteus ;—ruptures his tendo-Achillis ;—is elected surgeon to St. George's Hospital ;—removes to Jermyn-street.—Dr. Hunter's liberal offer to the Government rejected.—Mr. Hunter's house-pupils.—The pupils of distinguished surgeons themselves become distinguished.—Dr. Jenner;—his immortal discovery of vaccination.—Mr. Hunter's treatise on the teeth;—his marriage.— Mrs. Hunter.

A termination having been put to the late war, at the earnest desire of all parties, there was little probability that Hunter would be again called into active service by a renewal of hostilities; and as his health was re-established, he determined on immediately settling himself in London. The situation which he had occupied in Dr. Hunter's school was now filled by Hcwson, who had been taken into partnership soon after Hunter quitted England ; and as this gentleman's talents, both as a lecturer and as a practical anatomist, were of a high order, and enabled him to fill the post with credit to himself and advantage to the establishment, there was no prospect of a vacancy soon occurring in this quarter. It may indeed be doubted, even if the situation had been open, whether Hunter would have again entered into partnership with his brother; for it would appear from Sir Everard Home's statement, that their former connexion had not been one of entire harmony ; and that indeed the only tie which bound them together, long after other considerations would have led to a separation, was John Hunter's extraordinary skill as an anatomist, and the valuable contributions which he was continually making to Dr. Hunter's museum. For the future, then, Hunter was to depend on his own unaided exertions: consequently, though his situation was one of more independence than that he before occupied, it must also have been one of more anxiety, as he had nothing certain to depend on beyond his half-pay. The circumstances under which he commenced his career in London must be considered, however, to have been on the whole unusually advantageous. His age was sufficiently advanced to inspire his patients writh confidence; he had a brother established 26 THE LIFE OF JOHN HUNTER. in extensive practice as a physician and accoucher; and the abilities he had manifested in his former situations had made him favourably known, not only in the army, but to many of the most eminent literary and scientific men of the day. With such advantages, it might have been expected that his unwearied industry and eminent natural endowments, improved as they had been by an education under the first surgeons of the day, and by the personal experience which three years of active service had afforded him, would have certainly and speedily introduced him into a large share of profitable practice. Hunter was, however, destined to undergo a long trial of those qualities of passive fortitude and active perseverance, of which few situations in life demand a larger share than that a young man commencing practice in the higher branches of the profession of law or medicine in London ; for assuredly it needs no small degree of fortitude to bear up against the disappointment of a young man so placed must experience, in finding his merits overlooked, whilst the world is showering wealth on many around him whom he, at least, thinks far less deserving than himself. It requires, too, much steady perseverance constantly to keep in view the destined goal, resisting the allurements which have so often led men of superior talents to desert the arduous contest, and devote themselves to the pursuits of literature or of science ; pursuits which, though delightful, can seldom be extensively followed without the neglect of objects more essential to those who seek for fortune, as well as fame, from the practice of a profession. Various circumstances combined to render Hunter's success in practice far less rapid than might have been anticipated. Of these, one of the most obvious was that of the field being already occupied by several men of real merit in their profession, and who by their writings had contributed largely to the improvement of surgery. First of these, and facile priiiceps, stood Pott, in the prime of life, and in the zenith of his fame, who though he had never received, because he had never solicited, those titles and posts cf honour which are usually bestowed on the leaders of our profession, yet had raised himself by his eminent abilities and industry, and by his gentlemanly manners, to the highest place in the esteem of his professional brethren and the public. The second stations were ably filled by Bromfield and Sir Ccesar Hawkins, surgeons to St. George's Hospital; and Samuel Sharp and Warner, of Guy's. These divided amongst them the greater part of the civil practice, whilst Adair and Tomkins, from their long connexion with the army, enjoyed the chief share of what accrued from that quarter. The narrowness of his income was no doubt also an obstacle to Hunter's success: for though his personal habits were very inexpensive, his scientific inquiries required more money than he could wrell afford. He was therefore obliged to be content with establishing himself in the plainest manner, and living a retired life ; and THE LIFE OF JOHN HUNTER. 27 though this no doubt enabled him with more freedom to pursue those important objects in which he was about to engage, yet it would not be likely to conduce to his speedily increasing his professional connexions. It is in this respect, that, cceteris paribus, a man commencing with a moderate share of fortune has a decided advantage over the fortuneless ; for though it has been truly said that " moneys are not the sinews of fortune, but the sinews and steel of men's minds,—wit, courage, audacity, resolution, temper, industry, and the like," yet even he who declared this, has allotted the second place to " wealth and means." But besides these external difficulties which most men have to struggle with in a greater or less degree at the outset of life, there were in Hunter's case some great impediments arising out of his own character. He was deficient in those refined gentlemanly feelings, and those conciliating manners, which in all situations go far to win the good will of those whom we are in the habit of meeting in the daily intercourse of life, and are especially requisite iri the medical profession. Conscious of great mental superiority, he was too apt to show this in a rude and overbearing manner, towards men who in station were his equals, and exhibited somewhat too large a share of that " pride of port" which the poet assigns to those

Intent on high designs, a thoughtful band, By forms unfashion'd, fresh from Nature's hand.

Consequently, though the intrinsic excellences of his character insured him the friendship of a few, who knew and estimated his worth, this fault raised up against him many bitter enemies, and prevented him from ever becoming a general favourite with the profession. It might probably with justice be said, that of all who have attained to the highest rank as surgeons, no one ever rose so entirely by the pure force of superior talents as John Hunter, or was less indebted than he was for his success to the good will and assistance of his contemporaries. Hunter had also a great contempt for those minor tactics, which constitute so large a part of what has been aptly called the art of rising in the world; and they who have carefully watched the progress of men to fortune, know full well how much of their success has often been due to the judicious management of these auxiliary means. It would be egregious folly to suppose that a man could ever attain to high repute as a surgeon in London, without possessing a large share of the essential requisites for the practice of his profession ; but, on the other hand, it requires no great penetration to perceive that the vast difference in the amount of her favours, vouchsafed by Fortune to her different votaries, must be accounted for in some other way than by the amount of professional talent possessed by each. " He that is only real had need have exceeding great parts of virtue," says Bacon, " as the stone had need be rich, 28 THE LIFE OF JOHN HUNTER. that is set without foil;" and we need not a better illustration of the truth of this observation, than is afforded by Hunter's tardy progress in the path to fortune, compared with the rapid strides of others, who in professional attainments would be the first to acknowledge themselves but the humble disciples of this great master. But after all, perhaps, the principal reason why Hunter was so long in obtaining a large share of practice was, that he looked not as most men do, to the acquisition of fortune as the end for which he was labouring; but, on the contrary, considered wealth only as a means by which he might advance the far more important objects he had in view. His powerful mind was unceasingly stimulated by an ardent desire to forward the acquisition of those branches of knowledge which to him appeared best fitted to promote the improvement of his profession ; to this object was devoted every hour that he could spare from his daily avocations, or snatch from the time allotted by others to sleep, and to promote this end he was always ready to sacrifice the claims of worldly prudence and self-interest. To witness an interesting or extraordinary case he would take any trouble, or go almost any distance, without a chance of pecuniary recompense; but to the daily routine of practice he always returned unwillingly, and even when he had acquired a lucrative and extensive business he valued it only as affording him the means of pursuing his favourite studies. This-feeling he would often express to his friend Mr. Lynn, when called to see a patient, by saying, as he unwillingly laid by his dissecting instruments, " Well, Lynn, I must go and earn this d-----d guinea, or I shall be sure to want it to-morrow."# As a means of increasing his income, Hunter determined on delivering lectures on anatomy and operative surgery to a private class. These he continued for several years; but so far were his talents and his enlightened views, from exciting the attention they merited, that his hearers never amounted to twenty. Amongst them, however, were numbered Cline, Lynn, Brande, Adams, Vaux, and Justamond. " Dr. Garthshore,f too," says our modern Democritus, the late worthy and facetious William Wadd, "occasionally looked in, wound up his watch, and fell asleep." Hunter's leisure hours were never allowed to remain unemployed. He returned to the study of comparative anatomy with increased

* Hunter was much addicted to swearing, and constantly interlarded his conversation with expressions of this sort. In relating anecdotes respecting him, the author has generally omitted these expressions, since the objections to introducing them appeared to him greatly to outweigh any advantage that such verbal exactness could afford. -f- Dr. Garthshore was quite a physician of the old school, always well dressed, and exceedingly polite, and a great favourite with the dowagers. He was intimate with John Hunter, who did not however treat him with much ceremony. One day the Doctor, on entering the dissecting-room where Hunter was at work, began as usual with great empressement, " My d-e-a-r John Hunter"—" My dear Tom Fool," replied Hunter, looking up and imitating the tone and manner of the astonished Doctor. THE LIFE OF JOHN HUNTER. 29 delight; and to furnish subjects for his researches, he obtained the refusal of all animals which chanced to die in the Tower, or in those smaller zoological collections, which used at that time, more frequently than at present, to perambulate the country; and to insure the good will of the owners, he used to allow them a life interest in any rare animals he was able to purchase, oil condition that their carcases were restored to him after their decease. All the money he could spare was devoted to procuring curiosities of this sort, and Sir Everard Home used to state, that as soon as he had accumulated fees to the amount of ten guineas, he always purchased some addition to his collection. Indeed, he was not unfrequently obliged to borrow of his friends, when his own funds were at a low ebb and the temptation was strong. " Pray, George," said he one day to Mr. G. Nicol* the bookseller, with whom he was very intimate, " have you got any money in your pocket?" Mr. N. replied in the affirmative. " Have you got five guineas 1 because if you have, and will lend it to me, you shall go halves." "Halves in what ?" inquired his friend. " Why, halves in a magnificent tiger, which is now dying in Castle Street." Mr. Nicol lent the money and Hunter got the tiger. It was probably about this period that Hunter laid the plan of those vast researches into the animal ceconomy, to the execution of which the best hours of his future life were to be devoted. At the time he commenced his labours, surgery, though holding a far more respectable station as a practical art than it had done fifty years before, was yet destitute of those sound general views of the nature and treatment of disease which constitute the foundation of practice in the present day, and the possession of which justly entitles it to claim the rank of a science. The able men who, in this country and on the Continent, immediately preceded Hunter, had succeeded, by the exercise of correct observation and sound judgment, in removing a load of absurd practices with which the art had been clogged; but the improvements suggested by them depended for the most part on isolated experience, and were defi-

* Mr. Nicol, bookseller to the king, and a highly accomplished scholar, was father to the present Mr. W. Nicol of Pall Mall, who probably owes his life to Hunter's interference. Mrs. Nicol, who was asisterof Cruikshank, had lost five children, and was in the family-way for the sixth, the present Mr. N. Hunter, in passing one day, dropped in, and asked Mr. Nicol whether he intended to kill this, as he had killed all the rest of his children. Mr. N., who was a North-countryman, had on false principles endeavoured to inure his children to cold and rough usage, thinking that if they could not survive this they would never live to be reared to manhood. Not understanding such a question, therefore, he demanded of Hunter what he meant. " Why," said Hunter, "do you know what is the temperature of a hen with her callow brood ? because if you don't, I'll tell you." He then proceeded to explain the necessity of warmth to young animals, and convinced Mr. Nicol of the propriety of changing his plan ; which he did, and with complete success. The justice of Mr. Hunter's remarks on this subject, which is one of great importance, has been beautifully illustrated by Dr. Edwards's admirable experiments in his work "On the Influence of Physical Agents on Life," &c. 30 THE LIFE OF JOHN HUNTER. cient in a solid and satisfactory foundation upon well known principles of the animal ceconomy. As yet little had been done towards explaining the real nature of diseases, by showing in what particulars they are allied to natural processes, and what are the aberrations from those processes, which give them their peculiar character. Nor were the actions by which Nature operates in the cure ot diseases at all better understood, and the most vague notions prevailed respecting the important functions of nutrition and absorption, and the processes of adhesion, suppuration, granulation, &c; the right understanding of which, forms as it were the very cornerstone of a good surgical education at the present day. Hunter perceived the want of this knowledge, which in his opinion could alone furnish a sure foundation for the future improvement of surgery; and it was to contribute towards supplying the deficiency that his labours were hereafter to be unceasingly directed. He clearly saw, that in order to obtain just conceptions of the nature of those aberrations from healthy actions which constitute disease, it was necessary first to understand well the healthy actions themselves: and these required to be studied, not in man alone, but throughout the whole animal series, and even to receive further elucidation by comparison with the functions of vegetable life. It was no less an undertaking, then, than the study of the phenomena of life, in health and disease, throughout the whole range of organised beings, in which Hunter proposed to engage ; an undertaking which required a genius like his to plan, and from the difficulties of executing which, any mind less energetic, less industrious, and less devoted to science than his own would have shrunk. In pursuing these researches, he strove not, like many of his more learned but less philosophic predecessors, to unravel the mysteries of nature by taking up some principle d, priori, and seeking for facts to support his theory. On the contrary, he followed, in the strictest manner, the inductive method laid down by the great father of modern philosophy, as the only sure though arduous road to knowledge. He aimed not at discovering the essence of life, satisfied that this was beyond the province of philosophical research ; but he sought to know how the various organs are constructed, and how they act in accomplishing those various processes 'by which the presence of this principle is manifested. Nor was he content to acquire his information at second hand. Instead, therefore, of referring to the discoveries detailed in books,* he appealed directly to Nature herself, and rested nothing upon the facts related by others, until, by the evidence of his own senses, he had ascertained their truth. As the labours of Hunter in this field of knowledge were con-

* It often, therefore, happened to him, as it has done to others, to find that he had been anticipated in many discoveries : such confirmations, however, of previously discovered truths are always valuable, particularly when they depend on a distinct line of proofs. THE LIFE OF JOHN HUNTER. 31 tinued during his whole life, and as the various discoveries he made will require to be mentioned in noticing his publications, and more fully in the chapter devoted to a description of his museum, it will be unnecessary to enter into a detail of them in this place. As many of the inquiries which he was desirous of instituting could not be carried on conveniently, if at all, in the centre of a crowded city, he purchased a piece of ground called Earl's Court, at Brompton, about two miles from London, and built a small house, where he used to spend much of his time, and where he pursued most of those researches which form the subject of his papers in the Philosophical Transactions, or are detailed in his work on the Animal CEconomy. Here it was his delight to spend an hour or two, amono-st the strange inmates congregated from all parts of the globe,°engao-ed in observing their habits and instincts, and amusing himself in making them exert their various methods of self-defence against his playful attacks. As might be expected, he sometimes got himself into perilous situations in his character of assailant. On one such occasion he was thrown down by a little bull which the Queen had given him, and with which he had been wrestling; and had not one of his servants accidentally seen his danger, and driven off the victor, he would not have escaped without severe injury. In another of his adventures, still more serious consequences might have ensued. Two leopards, which he kept chained in an outhouse, broke from their confinement, and got into the yard with the dogs: a fierce encounter immediately commenced, the noise of wntch alarmed the neighbourhood, and quickly brought out Hunter to inquire into its cause. He found one of the leopards engaged with the dogs, whilst the other was making his escape over the wall, and instantly, though quite unarmed, he ran up and laid hold of both the animals, which fortunately submitted to be led back to theuden and secured. When the danger was over, however, he became «o agitated at the recollection of it, that he fainted. In 1767 he was elected a Fellow of the Royal Society; and although persons, except on account of their rank, are not generally admitted members before they have furnished some paper of original research to be read before the Society, yet this custom seems not to have been rigorously enforced in Hunter's case, as the only communication he had made was an appendix to a paper by Ellis on a new marine animal, the Proteus ; nor did he contribute anv entire paper to their Transactions until five years after: he was, however, a very regular attendant at the meetings of the Society, and, with Sir C. Blagden and others, used to meet and discuss papers, which had been presented, on topics of interest. It is somewhat singular that John Hunter should have been elected before his brother William, who had been ten years longer in London, and certainlv at this time occupied a higher station in

P1!iCw0aPsitn,htanyeardttt he —! his tendo-Achinis whi,, dancing, after the muscles of the leg had been fatigued. He did 32 THE LIFE OF JOHN HUNTER. not confine himself to bed for this accident, but continued to walk about during the cure. His mode of treatment was to keep the heel raised, and to compress the muscle gently with a roller, by which any fresh separation of the ends of the tendon by spasmodic and involuntary contractions of the muscles was prevented, for he found that by no voluntary impulse could he excite them to contract after the rupture of their tendon, '• the muscle refusing to act as if from a sense of imperfection," as he expressed it. This accident led him to examine into the process by which divided tendons are reunited. He divided the same tendon in several dogs, by introducing a couching-needle under the skin at some distance from it, and killed the dogs at different periods to see the progress of the union, which was found to be similar to that of fractured bones where the skin is not wounded. It was ascertained at Mr. Hunter's death that the union of the ruptured tendon was by ossific deposition. In 1768 a vacancy occurred at"St. George's Hospital, by the retirement of Gataker, the translator of Le Dran; and Hunter became a candidate for the situation. He was opposed by Mr. D. Bayford, but being supported by the powerful interest which Dr. Hunter possessed, he was elected surgeon on the 9th of December by a majority of 114 votes against 42. Soon after this he was chosen a member of the Corporation of Surgeons; but he seems not to have assimilated well with his brother corporators, for he gave them but little of his society. By his election to the hospital he was ensured the means of making his talents as a surgeon more generally known, and was enabled to obtain as private pupils, on advantageous terms, young gentlemen coming to town to complete their medical education.* This was further facilitated by his removal to a more commodious house in Jermyn-street, which his brother had just vacated. Dr. Hunter had, in the year 1765, in the most liberal way proposed to the then Ministry to build a public theatre of anatomy, at an expense to himself of 7000/., and to endow a professorship of anatomy in perpetuity, on condition that they would grant a piece of ground in the Mews as a site for the building. But Lord Grenville and his colleagues, with the apathy which the English Government has too often shown to the interests of science, declined the offer. Lord Shelburne was desirous that the plan should be exec uted by subscription, and generously requested his name should be put down for one thousand guineas. Dr. Hunter's delicacy, however, led him to decline this proposal, and he determined to erect a building at his own expense. For this purpose, he purchased a spot of ground in Great Wind-mill-street, where he built a spacious house, with a theatre and museum, to which he removed in 1770 passing over the lease of his house in Jermyn-street to his brother John. t

* Hunter received a fee of 500 guineas with each of his pupils, who were bound to him for five years. THE LIFE OF JOHN HUNTER. 33 Amongst those gentlemen who successively became inmates of Hunter's house, as private pupils, were Dr. Jenner, Mr. Guy of Chichester, Mr. Kingston, Dr. Physick of Philadelphia, and" Sir Everard Home. Mr. Lynn and Sir A. Carlisle, although not living in his house, were admitted there on the most intimate terms, assisted in his dissections, and contributed several valuable preparations to his museum. All of these gentlemen have risen to high reputation in their various stations, and it is not unworthy of remark, that of the eminent surgeons of which this country has had to boast, by far the greater number have pursued the most important part of their professional education under the roofs, and as the private pupils, of the most able of their predecessors in the art. This may no doubt, in some cases, be accounted for by supposing that the disciple had previously shown such talent as to lead his friends to seek the best situation for its improvement; but more has been probably due to the stimulus imparted to their energies by the examples before them, and still more to the advantages derived from daily witnessing the best modes of practice, and receiving information on those nicer distinctions in treatment which can never be fully conveyed in lectures, but the knowledge of which forms a distinguishing mark of the accomplished surgeon.* It is to the credit of the gentlemen above named that they con-. tinued on friendly terms with Hunter until his death, for he not unfrequently conferred his friendship rather hastily on young men if he perceived any thing in their characters which pleased him, but as suddenly threw them off again on finding them to be of less sterling metal than he had anticipated.! ■ Dr. Jenner was amongst the earliest of Hunter's pupils, having become one in 1770, when he was in his twenty-first year, and Hunter in his forty-second. His mind was ever strongly impressed with respect and esteem for the character of his great master, whose vigorous and independent intellect excited the admiration,

* Thus we find that most of the surgeons who in the present day enjoy the largest share of the public confidence are, as it were, the direct mental descendants of the men who a century ago introduced the first important improvements into modern surgery. Cheselden, Nourse, and Douglas, were then the leaders of our profession, of whom Sharp, Pott, and the Hunters were the immediate pupils ; they, again, became the instructors of Cline, Lynn, Home, Abernethy, Carlisle, Macartney, Sir James Earle, and Cooper; and from them the mantle has descended to a Brodie, a Lawrence, a Green, an Earle, and others, who now occupy with so much credit to themselves the places which their great predecessors adorned. f Hunter set a high value on anatomical skill, and especially on dexterity in making preparations. Sir Anthony Carlisle stood high in his good graces on account of his ability in this art; but he used to abuse Sir Everard's clumsy fingers, swearing " that his fingers were all thumbs, and that he would never have sense enough to tie down a bottle." This was of course a mere sally of passion : his engaging him as his assistant, and leaving him the care of all his patients when unable to attend them himself, sufficiently proved the good opinion he entertained of the abilities of his brother-in-law, who was, there can be no doubt, a very skilful surgeon. 5* 34 THE LIFE OF JOHN HUNTER. while his kind, free, and manly nature insured the affection of such a pupil. Their intercourse did not cease on Jenner's leaving London, but was kept up by letter until within a short period of Hunter's death. Many of the letters written by the latter have been published in Dr. Baron's Life of Jenner ; and these, as well as some additional ones which Robert F. Jenner, Esq., of Berkeley, has kindly permitted to be introduced into this work, furnish interesting and truly characteristic memorials of the mind of him who penned them ; for though generally but brief, and often faulty in orthography and in grammatical construction, they everywhere show the vigour and originality of his thoughts, and the untiring ardour with which he prosecuted his researches. Several of these letters will be inserted in the next chapter, but the following, though written two or three years later, may be introduced here, as evincing the interest Hunter felt in the welfare of a deserving pupil. Jenner, on the other hand, never mentioned Hunter but in terms of regard and affection; his usual appellation for him was "the dear man," an epithet which is used, in speaking of him, by others of his friends who still survive, and which shows how strong a hold he had acquired on the esteem of those who were on sufficiently intimate terms with him to know his real worth. "Dear Jenner, " I received yours, and was extremely happy to hear of your success in business : 1 hope it will continue. I am obliged to you for thinking of me, especially in my natural history. 1 shall be glad of your observations on the cuckoo, and upon the breeding of toads : be as particular as you possibly can. If you can pick me up anything that is curious and prepare it for me, either in the fish or flesh way, do it. Pictures* have been very cheap, but the season is now over. There will be but one sale, viz. Fordyce's ; but I believe all his pictures are exquisite, and will go beyond you or me. Since you wrote to me I purchased up a small landscape of Barrett's, of cattle and herd : I gave five pounds seven shillings and sixpence : it is one of his eight-guinea pictures. You shall have it or not, as you please. I have one of the same size that I bought of him some time ago. " I saw the young lady, your patient: I do not know well what can be done. If it is possible to pass a bougie from the nose up the duct to the sac, it mioht be of service; but nothing but a solid can be of any use as a local application. Her general habit should be attended to, such as sea-bathing, or cold bath, using a good deal of gentle exercise, such as getting up early in the morning, riding, &c. She might take gentle mercurials with the bark and cicuta. Let°me hear from you soon. " Ever yours, John Hunter." At the time this was written Jenner was practising as a surgeon at Berkeley in Gloucestershire. Here he remained for many years, and conducted those inquiries which, led to the introduction of vaccination. It seems that whilst in London he frequently mentioned the opinion that prevailed in the dairy districts, that persons who had had the cowpox were safe against the infection of small- * Hunter was very fond of pictures, and valued himself on his connoisseurship in the art: his other pursuits, however, prevented his indulging his taste by the purchase of many oil paintings, but of prints he had a large and valuable collection. THE LIFE OF JOHN HUNTER. 35 pox. Hunter considered the subject worthy of investigation, mentioned the opinion occasionally in his lectures, and recommended Jenner to prosecute further inquiries into its truth. There is no ground, however, to suppose that Hunter assisted him in the investigation, as has sometimes been insinuated. On the contrary, it is quite evident that the merit of conducting every part of it belongs exclusively to Jenner. As his letters to Hunter have been destroyed, it is not possible to say what communications he made to him on the subject, for no allusion is made to the inquiry in Hunter's letters. It would seem that in 1788 Jenner was in London, and on that occasion showed a drawing of the vaccine pustule, as it appeared on the fingers of milkers, to several medical men, and amongst the rest, no doubt, to Hunter. Indeed there exists, amongst the Hunterian drawings, a rough sketch of the pustule, as seen under the above circumstances, on the envelope of a ietter from Jenner, without date. It was not, however, until eight years after this, and three years after Hunter's death, that the question was subjected to the experimentum crucis, by actually inoculating a boy with lymph from the hand of a person affected with cowpox, and afterwards submitting him, without effect, to inoculation with variolous matter: and even then nearly two years elapsed before Jenner considered the inquiry sufficiently complete to be made public* In May 1771, Hunter published the first part of his "Treatiseon the Teeth."f This contained the natural history of those organs in their healthy state, and was followed in 1778 by a second part, in which he treats of their diseases. It was the first work on the subject, which, in addition to an accurate anatomical description, furnished comprehensive views of the physiology and pathology of

* Various attempts were made to deprive Jenner of the credit of his discovery, but unjustly. That an opinion prevailed extensively in the dairy districts, that a person who had been infected with cowpox was no longer liable to smallpox, is certain ; but no one who is acquainted with the utter groundlessness of many prevalent opinions on medical matters would put much faith in such an opinion until supported by direct experiments, instituted by a competent person. It would further appear, that a farmer Jesty had actually inoculated some of his family with matter taken from the teat of a cow ; and claims to the discovery of vaccination were made on behalf of a Mr. Nash of Shrewsbury, on similar grounds. But was Dr. Jenner acquainted with either of these cases 1 And if not, how do they affect his merit any more than the existence of printing at an early date amongst the Chinese detracts from the merit of the discovery in Europe] With regard to Mr. Nash's case, Dr. Baron states that they were proved to have been cases of smallpox inoculation. But supposing them to have been cases of vaccination, does not his silence on the subject until the publication of Jenner's work argue either a want of faith in his own powers of investigation, or a want of courage to publish the facts'? Does not the whole merit belong to Jenner of distinguishing the true from the spurious vaccine—of tracing the origin of the disease—of subjecting the opinion to the test of rigid experiment, and of conducting his inquiries to a triumphant conclusion, amidst difficulties and opposition of no ordinary kind ? t It is said that the proceeds of this publication, which came out only two months before his marriage, were appropriated to defraying the expenses attendant on that event. 36 THE LIFE OF JOHN HUNTER. these organs. Like all Hunter's productions, it evinces marks of accurate observation and sound judgment; and though too brief in some of its descriptions, and not aTtogether free from errors and omissions, which subsequent inquiries have pointed out, it continues to hold its place as one of our standard surgical works. It needs, indeed, but to receive the additions and corrections of the able practitioner and accomplished naturalist who has undertaken to revise it for this edition of Hunter's works, to become one of the best treatises on the subject in this or any other language. Hunter had for some years been engaged to Miss Home, daughter of Mr. Home, surgeon to Burgoyne's regiment of light horse, and sister of Sir Everard Home. "As she was without fortune, and as his income, at the time they first became acquainted, was considerably under a thousand a "year, and scarcely sufficed for his own expenses, their union was deterred until he was able to arrange his affairs sufficiently to allow of their marrying. This he had now succeeded in doing; and as his practice was yearly augmenting, they were married in July of the present year. Mrs. Hunter was an agreeable, clever, and handsome woman, a little of a bas bleu, and rather fond of gay society, a taste which occasionally interfered with her husband's more philosophic pursuits; for, though fond of mixing in society at his own house and at the houses of others, it was not exactly in such as is generally to be found at fashionable soirees. He sought company, not so much as a relaxation as because he preferred acquiring knowledge from conversation rather than from books; and this being the case, he naturally preferred the company of able and scientific men, to that of the gay circle in which Mrs. Hunter's brilliancy was fitted to shine. So far was he indeed from finding relaxation for his mind in mixed society, that he really experienced fatigue from remaining long in company where the conversation wanted connexion ; and he therefore occasionally interposed [his marital authority to check the inroads of these troops of idlers.* No serious disturbance to their concord, however, seems to have arisen from this very natural difference in the tastes of Mr. and Mrs. Hunter, and there is every reason to believe that this alliance was a source of great consolation and happiness to him during the remainder of his life. The fruits of their union were four children, two of whom died young; the other two are still living,—John his eldest son, and Agnes, who married Captain, afterwards Sir James Campbell.

* Hunter's mode of exerting this authority was occasionally somewhat too unceremonious. On returning late one evening, after a hard day's fag, he unexpectedly found his drawing-room filled with musical professors, connoisseurs, and other idlers, whom Mrs. Hunter had assembled. He was greatly irritated' and walking straight into the room, addressed the astonished guests pretty much in the following strain : " I knew nothing of this kick-up, and I ought to have been informed of it beforehand; but as I am now returned home to study, I hope the present company will retire." This intimation was of course speedily followed by an exeunt omnes. THE LIFE OF JOHN HUNTER. 37 CHAPTER IV.

Mr. Hunter's paper on the digestion of the stomach ;—his museum ;—his private practice;—his illness, attended with a cessation of the heart's action ;—his correspondence with Dr. Jenner ;—his paper on the torpedo ;—his lectures on surgery ;—his character as a lecturer.—Hunter effects a revolution in surgery ; __his paper on the receptacles for air in birds, and on the stomach of the gillaroo trout.—The general character of his monographs.—Mr. Bell.—Mr. Hunter's warmth of temper;—his method of employing his time;—his punctuality.—Anecdote of Mr. Cline.—Dictates his various compositions ;—his domestic habits;—contemplates the establishment of a school of natural history ;—his paper on the heat of animals and vegetables;—is appointed surgeon extraordinary to the King;—his paper on the recovery of drowned persons ;— Croonian lectures;—correspondence;—is attacked with an alarming illness, attended with peculiar symptoms;—his visit to Bath ;—his character as an experimentalist;—his second part on the teeth;—his expenses and difficulties.

Hunter had now been five years a Fellow of the Royal Society; but deterred, partly by the difficulty he experienced in literary composition, and partly by an unwillingness to make any of his observations public until he had thoroughly satisfied himself of their correctness, and investigated a subject in all its bearings, he had contributed no paper to the Philosophical Transactions since his election. About this time an opportunity offered for making known his opinions on a physiological phenomenon which had hitherto entirely escaped investigation, and on which, at the instance of Sir John Pringle, he was induced to communicate his thoughts in a memoir to the Royal Societv. Pringle was at this period the President, and had distinguished himself in this honourable post by the learned and eloquent orations he had annually delivered, on presenting the Copley medal to those who had successively gained it by their important contributions to science. He and 'Hunter were on intimate terms, and occasionally met in consultation, and on the present occasion chanced to be engaged together in examining the body of a man who had died under Sir J. Pringle's care, of "some disease in which the stomach was thought to have been not implicated. To Pringle's surprise, however, on opening this organ an extensive perforation was observed at its great end, an alteration of structure for which he could not account, until Hunter informed him that he had frequently met with such an appearance, both in men and animals, and attributed it to the action of the gastric juice on the coats of the stomach, after the death of this organ. This explanation forcibly struck Pringle, who was the more interested in the subject from having himself been engaged some years before in experiments on digestion. He accordingly 38 THE LIFE OF JOHN HUNTER. urged Hunter to commit his thoughts to paper, and communicate them to the Royal Society, a request with which the latter, though somewhat unwillingly, complied. His memoir was accordingly presented, and read on the 18th of June, and was published in the Transactions for the year. This curious question in physiology did not at the time excite much attention. Spallanzani, who made several experiments, with a view to its further elucidation, concluded by rather throwing doubt on the possibility of this post mortem digestion, and the point was thus left sub judice. Of late years more attention has been paid to the inquiry, and though several continental pathologists, and amongst others Cruveilhier, have maintained that the appearance described by Hunter is always caused by morbid action going on during life, the experiments of Dr. Carswell, detailed in the Edinburgh Medical and Surgical Journal for October 1830, have fully proved the correctness of Hunter's explanation. This gentleman killed several rabbits during digestion, and hung them up by the hind legs, when the depending part of the stomach was always found more or less digested. The gastric juice of one rabbit was conveyed into the stomach of another previously killed, and digestion of a part of its stomach was the consequence. In the autumn of this year Hunter's brother-in-law, Mr., afterwards Sir Everard Home, became his pupil. He describes the museum as at this time beginning to assume an imposing degree of magnitude. All the best rooms in the house were already devoted to its reception ; and though, from the increase of his professional engagements, Hunter had less time to devote to comparative anatomy, yet as he always spent three or four hours before breakfast, and as much time as he could spare during the remainder of the day, in the dissection of animals, he was constantly adding to its size and value. His increasing reputation as a naturalist, also, facilitated to him the acquisition of objects on which to pursue his researches, as it induced scientific travellers to send him specimens of rare and curious animals, assured that they could not better forward the cause of science than by conferring them on one so ardently devoted to its promotion. " Hunter's private practice and professional character," adds Home, " were at this time advancing fast;" and yet his income, until 1774, never reached a thousand a year, a convincing proof how much his fame as a naturalist had outrun his fortune as a surgeon. In the spring of the year following Hunter suffered under an alarming attack of spasm, apparently seated about the reo-ion of the pylorus, but attended with a cessation of the heart's action, which lasted three quarters of an hour, in defiance of various active remedies suggested by Dr. Hunter, Sir George Baker, Dr. Huck Saunders, and Dr. G. Fordyce, who were hastily called in on the occasion. The complaint was probably of a gouty nature, for he had this year escaped a regular fit of gout, such as he had suffered from during the spring of the three preceding years; but the im- THE LIFE OF JOHN HUNTER. 39 mediately exciting cause was a violent mental affection, the nature of which Sir Everard Home does not mention. During this attack the sensation and voluntary actions continued unaffected, and Hunter continued to respire by a voluntary effort, with a view of keeping himself alive ; though, as he afterwards observed, the continuance of respiration was probably of no service, as the circulation had ceased.* This seems to have been the first warning he received of the existence of disease about the heart; although it never again manifested itself by an exactly similar attack; nor was it until several years after that this organ became permanently deranged in its actions. It has been stated, in the preceding chapter, that soon after Jenner settled at Berkeley, Hunter entered into a correspondence with him, which was kept up nearly to the period of his own death. Hunter's letters alone have been preserved, and these consist, for the most part, of requests to his former pupil to procure for him various objects of natural history, which a residence in the country rendered easily attainable, or of directions respecting experiments to elucidate those inquiries into the vital actions, in which Hunter was constantly engaged, and in the prosecution of which Jenner was always ready to lend his valuable aid. The letters seldom bear any date, but when this can be ascertained, either from the postmark or from the nature of their contents, it will serve as the guide for their insertion in this and the succeeding chapters. The following one appears to have been written somewhere about this time. " Dear Jenner, " I received yours, as also the cuckoo's stomach : I should like to have a few more, for they do not all show the same thing, f If possible, I wish you could remove the cuckoo's egg into another bird's nest, and tame the young one, to see what note it has. There is employment for you, young man ! If you collect eggs, you should also collect the nests, and I do not care how many you send. I wanted a crow's nest as also a magpie's, in the branches of the trees where they are built, but I am afraid it is now too late. "This evening, looking into my book of patients to scratch out the name of one who had paid me, and whose name began with M., I saw a Mr. Matthews of Berkeley, recommended by you. He did not pay me. I forget whether he was recommended by you as a friend to serve him or me ; if it was to serve him, I scratch him out of my book. Do you keep an account of the observations on the * This curious fact in physiology has never been satisfactorily explained. Bichat and his school insist on the necessity of arterial bjood constantly circulating through the brain in order to the continuance of its functions, but here we find its functions going on though the circulation had ceased. In the collapse of cholera, the sensorial functions continue perfect for hours after all perceptible circulation has ceased, and when the blood is as dark as pitch. j The internal coat of the cuckoo's stomach is found thickly set with the hairs of caterpillars on which it feeds. These hairs are laid circularly over each other in one direction, showing the circular motion of the two portions of the gizzard, on each other, in grinding the food. It is to this, probably, that Hunter alludes, as there is a preparation in the museum showing this fact. Jenner had now commenced his observations on the hatching and rearing of the cuckoo, which were communicated many years after to the Royal Society. 40 THE LIFE OF JOHN HUNTER. cuckoo, or must I refer to your letters ? I want a nest with the eggs in it; also one with a young cuckoo ; also an old cuckoo. I hear you saying, there is no end of your wants. " Ever yours, "John Hunter."

The phenomena of electricity had of late begun deeply to engage the attention of scientific men. Mr. Walsh was one who had devoted much attention to the subject, and who had been making experiments, to ascertain whether the shock communicated by the Torpedo is analogous to that of an electrical battery. Being anxious to learn the exact'anatomical arrangements of the parts in which the peculiar power resides, he requested Hunter to examine them, a request with which the latter willingly complied, and in July communicated, in a paper to the Royal Society, an accurate description of the electric organs of the Ray, and pointed out the vast nerves with which they are supplied as the probable source of their peculiar power. In the autumnal session of this year, Hunter for the first time delivered a course of lectures exclusively on surgery. These lectures were for the first two years given gratuitously to the pupils attending St. George's Hospital, but after that the usual fee for admittance was required. It has been before observed that he appeared but to little advantage as a lecturer; his language, though forcible, was inelegant, and often coarse ;* his delivery was heavy and unengaging, as he rarely raised his eyes from his book; and as, in addition to this, the doctrines he taught were new, and often obscure and theoretical, his hearers were never numerous. The many who found it troublesome to think, and desired only straightforward directions for every day practice, sought other teachers ; for notwithstanding the length of the course, which in late years extended to eightysix lectures, he entered but little into the minuter details of practice, and gave little or no account of the, operations of surgery, but confined himself almost exclusively to the theory and principles of the art. It was an instance of Hunter's perseverance, that though his dislike to delivering himself in public was so great that he never commenced a course of lectures without having recourse to laudanum to relieve his uneasy feelings, he notwithstanding continued the practice of lecturing for many years. He was induced to this by other motives besides the more obvious one of increasing his reputation : his opinions were for the most part peculiar to himself; he was desirous of subjecting them to the test of public opinion, and * In speaking, for example, of a case of gun-shot wounds, he described the ball, as " having gone into the man's belly and hit his guts such a d—d thump, that they mortified." And in relating his own case, where secondary symptoms had ensued on inoculation with the matter of chancre, he repeated over so often, and in so peculiar a tone, " I knocked down the disease with mercury and I killed it," that the whole class at length burst into a loud fit of laughter. THE LIFE OF JOHN HUNTER. 41 thought this the best mode of doing it, until they were sufficiently matured in his own mind to be committed to print; he felt also that the practice of lecturing was beneficial to himself, by discovering to him the amount of knowledge he possessed on any subject, and when this knowledge was deficient.* In this respect he was accustomed to compare the process of preparing a lecture to that of a tradesman taking stock. Boldness and independence in the pursuit of truth, one of the striking characteristics of Hunter's mind, was well exhibited in these lectures. He attached no value to opinions, except they could be shown to be firmly based on fact: fallacious reasoning, though ingenious, he quickly saw through, and instantly demolished; and he was not more indulgent towards his own theories when he discovered them to be erroneous. To a pupil (Sir Astley Cooper) who asked with surprise, whether he had not the year before stated an opinion on some point, directly at variance with one he had just put forth; he replied, "Very likely I did; I hope I grow wiser every year:" and to the same purport he answered Professor Coleman (another of his pupils), who asked whether he had not written so and so; " Never ask me what I have said, or what I have written; but if you will ask me what my present opinions are, I will tell you." Occasionally, too, he would say to any of the pupils whom he saw taking notes, " You had better not write down that observation, for very likely I shall think differently next year:" and on one occasion, after lecturing for a considerable time, he stopped short, raised his spectacles, and said, " Gentlemen, I think you had better omit what I have been saying; the fact is, I had an idea when I wrote down this, but I have lost the train of thought connected with it, and I cannot now recall it."f Such a mode of lecturing was not likely to become popular; his class consequently never exceeded thirty, and not half that number derived much benefit by their attendance. Those, however, who would take the pains to understand what they heard, set a high value on these lectures, by which, perhaps even more than by his writings, Hunter originated that revolution in surgery, of the occurrence of which none can doubt, who compares the best surgical works written half a century since, with those of the present time.

* " Reading," says Lord Bacon, " makes a full man, conference a ready man, and writing an exact man." Public lecturing, and more particularly extempore lecturing, combines these advantages in a remarkable degree. f This was a difficulty he not unfrequently experienced. After thinking deeply, he would make short notes of his thoughts, on looking at which some time after he would find them unintelligible until his mind was prepared to fall again into the same train of reasoning. It may fairly be questioned, when Mr. Hunter had got so deep, whether he had not got out of his depth. At least from the specimens we have of his hypothetical reasoning, we have no reason to regret that he did not oftener indulge in it. Dr. Beddoes observed: "John Hunter fancied that what he could not find words for was very profound : but he was mistaken; whenever he found himself at a loss for words, he was labouring with the delivery of nothing."—Dr. Beddoes's Common Place Book. 6 42 THE LIFE OF JOHN HUNTER. We find, accordingly, that most of the eminent surgeons who immediately succeeded to the time of Hunter, were at one period or other attendants at his lectures; and that in effecting those improvements which they were the means of introducing into the practice of surgery, they pursued that path into which he had directed their steps at the very outset of their career. Besides those before mentioned, we must enumerate the names of Home, Carlisle, Abernethy, Astley Cooper, Wilson, Chevalier, Macartney, Coleman, and" Physick; and others might no doubt be mentioned, who have, like them, done honour to the surgical profession in this century. In 1774 two papers by Hunter were read before the Royal Society, and published in the Transactions. The first of these contains a general account of the receptacles for air which are found in the abdominal cavity, the cellular tissue, and bones of birds. In the second, a description is given of the stomach of the Gillaroo Trout, a peculiar species of trout found in some of the lakes in Ireland, the stomach of which is so thick and muscular, as to have led to the name of Gizzard Trout being applied to this animal. There is another paper on the subject, in this volume of the Transactions, by Henry Watson, and it is not uninteresting to observe the different manner in which the two men have handled the same topic. Watson has contented himself with giving a plain anatomical description of the organ, from which he draws the conclusion that it is not properly a gizzard, but only a very muscular stomach. Hunter arrives at the same conclusion, but has given interest to a rather meagre subject, by introducing it with a general view of the various modes in which the preliminary process of digestion, that of comminuting the food, is effected in different animals. He points out the analogy between the gizzard of granivorous birds and the grinders of mammalia; shows how, by imperceptible gradations, we pass from the membranous stomach to the gizzard ; and finally determines, that though the object to be effected in the stomach of the Gillaroo Trout is very much the same as in the gizzards of birds, yet that in structure it more resembles a true membranous stomach than a gizzard. The introduction of such general remarks was a common practice with Hunter in treating any anatomical question, so that the titles of his papers seldom afford us any adequate notion of their contents. He employs the subject treated of as a text, on which he freely expatiates, introducing valuable original researches of a physiological character as a prelude to some point in anatomy, which, separately considered, would possess little interest. Hunter's increasing professional avocations began now to render it impossible for him to devote as much time as he desired to extending and perfecting his collection. The field of his labours, too, was considerably increased; on the one hand, by the opportunities for the cultivation of morbid anatomy, which his connexion with a hospital, and his increasing private practice afforded him; THE LIFE OF JOHN HUNTER. 43 on the other, by the augmented stores of rare and curious animals, which the kindness of his friends, and the liberality of scientific men, continually accumulated on his hands. He therefore engaged Mr. Bell, a young artist of considerable merit, to reside in his house, and to devote himself, under his superintendence, to making anatomical preparations and drawings, and to the general care of the museum. Mr. Bell's engagement was for ten years, and he eventually remained fourteen, in the course of which time he became an accomplished anatomist, and added a large number of valuable preparations and several hundred admirable drawings to the collection. He was also frequently employed by Hunter as his amanuensis, and some of the catalogues now in existence are in his handwriting. The fact that Mr. Bell remained so much longer with Hunter than he originally engaged to do, is an evidence that he was not dissatisfied with his situation. Probably, like most of those who were intimately acquainted with this great man, he gradually acquired a strong personal attachment to him, which led him to tolerate the violent sallies of passion to which the inmates of Hunter's house were not unfrequently subjected on very trivial grounds. Home states that " Hunter's temper was warm and impatient, readily provoked, and when irritated not easily soothed;" and this account. is confirmed by most of those who were intimately acquainted with him. An intrusion on his studies, even by one with whom he was on friendly terms, would call forth expressions of strong disgust and impatience: an object of which he was in want being misplaced, would bring down all the vials of his wrath on the offender; and during these fits of passion he used to swear in the most outrageous manner, a vicious habit, which was not uncommon, even amongst men of education, fifty years ago, and to which Hunter was greatly addicted. The accession of Mr. Bell to his staff did not lead Hunter at all to relax in his own exertions; on the contrary, every hour-of the day, and of great part of the night, found him busily employed. He commenced his labours in the dissecting-room generally before six in the morning, and remained there until nine, when he breakfasted. After breakfast he saw patients at his own house until twelve,* when he made it a point to set forth on his rounds, even though persons might be in waiting for the purpose of seeing him ; for, said he, " these people can take their chance another day, and I have no right to waste the valuable time of other practitioners by keeping them waiting for me." Hunter was a great economist of time,

* The following note shows that Mr. Hunter went out at an earlier hour at one period of his life: " Dear Sir,—I can hardly be at home after 11 o'clock any day, but on Friday I will wait till half-after, and if that should not suit your convenience, and you do not come by that time, I will be at home by three to meet you. " I am your most obedient servant, ^ « Wednesday Evening. John Hunter. 44 THE LIFE OF JOHN HUNTER. and was always very punctual in fulfilling his appointments, to ensure which he kept a regular entry of his engagements in a book at home, and carried an exact copy of this in his waistcoat pocket, so that by a reference to the book he could always be found at any hour of the day, in the event of his being wanted. Any unnecessary discomposure of these engagements greatly annoyed him, and caused him to give vent to his feelings in no measured terms. The late Mr. Cline once excited his ire by an offence of this kind. He had engaged Hunter to meet him in consultation on a case in the afternoon, but in the course of his morning rounds saw another patient, respecting whom he wished to take Hunter's opinion, and accordingly, without giving him previous notice, appointed to call with him after the former engagement was ended. When the first visit was over, Cline mentioned the second appointment, on hearing of which Hunter got into a towering passion, and asserted that Cline had acted in the most unjustifiable manner in ihus deranging the whole of his arrangements for the afternoon.* Cline, who was of a very placid temper, was amazed to see such a storm excited by so trifling a cause, and said what he could to appease it. In this he succeeded, and Hunter soon recovering himself, turned to him, and in a very altered tone said, "Come along, then, let us go and see our patient." Hunter was equally strict in enforcing punctuality on his household; he dined at four, then the fashionable hour, and gave strict orders that dinner should be ready punctually whether he was at home or not. He was a very moderate eater, and set little value on the indulgence of the palate. During many of the latter years of his life he drank no wine, and therefore seldom remained long at table after dinner, except when he had company; but then, though he abstained himself, he was not willing to allow his friends to follow his example.f After dinner he was accustomed to sleep for about an hour, and his evenings were spent either in preparing or delivering lectures, in dictating to an amanuensis the records of particular cases, of which he kept a regular entry, or in a similar manner committing to paper the substance of any work on which he chanced to be engaged. When employed in the latter way, Mr. Bell and he used to retire to

* This attention to punctuality was also displayed by Hunter's nephew, Dr. Baillie, in as remarkable a degree. When accidentally detained beyond his time, he made it a point to forfeit one appointment to save the rest. He used to say: "I consider it not only a professional, but a moral duty to meet punctually my professional brethren of all ranks. My equals have a right to such a mark of my respect, and I would shudder at the apprehension oMessening a junior practitioner in the eyes of his patient, by not keeping an appointment with him." f " Come, fellow," said he, in his usual blunt way, to Mr., now Sir William Blizard, " why don't you drink your wine "?" Mr. B. pleaded in excuse a whitlow, which caused him much pain. Hunter would not allow the validity of the plea, but continued to urge him and ridicule his excuse. " Come, come John " said Mr^. Hunter, "you will please to remember that you were delirious for two days when you had a boil on your finger some time /ago." This turned the laugh against Hunter, who now ceased from importuning his guest. THE LIFE OF JOHN HUNTER. 45 the study, the former carrying with him from the museum such preparations as related to the subject on which Hunter was engaged; these were placed on the table before him, and at the other end sat Mr. Bell, writing from Hunter's dictation. The manuscript was then looked over, and the grammatical blunders, for Bell was an uneducated man, corrected by Hunter.* At twelve the family went to bed, and the butler, before retiring to rest, used to bring in a fresh argand lamp, by the light of which Hunter continued his labours until one or two in the morning, or even later in winter. Thus he left only about four hours for sleep, which, with the hour after dinner, was all the time that he devoted to the refreshment of his body. He had no home amusements, as cards, for the relaxation of his mind, and the only indulgence of this kind he enjoyed consisted in an evening's ramble amongst the various denizens of earth and air which he had congregated at Earl's Court, where he slept, and, with his family, spent the greater part of his time during the autumnal months. In 1775 Hunter entertained thoughts of establishing a school of natural history, in which he purposed himself to take the chief part; but as it was necessary that he should obtain the assistance of some young man of talent in carrying on the undertaking, and as none was better qualified for the office than Jenner, he applied to him in the following letter to say if he felt disposed and at liberty to join him.

" Dear Jenner, " I have received many things from you, and will thank you in the lump ; but while I thank you, I have a great scheme to communicate to you, and I want you to take part in it; but remember, it is as yet a most profound secret. My scheme is to teach natural history, in which will be included anatomy, both human and comparative. The labour of it is too much for one man, therefore I must have some one to assist; but who that person shall be is the difficulty. When running over a variety of people, you have come into mind among the rest. Now if it is a scheme you would like, and a possibility of your leaving the country,—at the same time, able and willing to lay down one thousand guineas,—I will send you the whole proposals; but if you cannot leave the country on any terms, then it is unnecessary to go any further; and all I have to beg is to keep it a secret. I would not have you mention it to Ludlow,----. &c. I proposed it to L---- before he left London, but his father objected, I believe, to the money. I know the scheme will be to your taste. Before you ask any of your friends, consult with yourself, and ask, Can I go to London, and can I give one thousand guineas for any chance that may be worth it ? Let me hear from you very soon. Yours, "London, May 24th. J. Hunter."

* Burke used to say that it was impossible for any man to arrive at great eminence by his own unassisted talents : the power to combine the assistance of inferior men, in subserviency to his own views, used always to constitute an essential part of his definition of a truly great man. This power Hunter possessed. All his pupils and intimate friends contributed more or less to the formation of his museum; fourteen years of Mr. Bell's life were devoted to this object; he called in the aid of the ladies of his family in the prosecution of his researches on the economy of bees, and he even carried this so far as to call on his coachman occasionally to act as amanuensis when Mr. Bell was otherwise engaged. There were no drones in his hive, 46 THE LIFE OF JOHN HUNTER. Jenner declined the offer, for what reasons cannot now be known, as his letters have been destroyed ; but it would appear, from Hunter's next letter, that the refusal was not unexpected, and we may judge, moreover, from his language, that he had already given up the project himself.

"Dear Jenner, August 2d. "I received yours, in answer to mine,which I should have answered. I own I suspected it would not do; yet as I did intend such a scheme, I was inclinable to give you the offer. " I thank you for your experiment on the hedgehog; but why do you ask me a question by the way of solving it? I think your solution is just; but why think 1 why not try the experiment? Repeat all the experiments upon a hedgehog as soon as you receive this, and they will give you the solution. Try the heat: cut off a leg at the same place ; cut off the head, and expose the heart, and let me know the result of the whole. " Ever yours, J. Hunter."

It is probable that Hunter abandoned his intention on finding that it was not likely to be attended with success proportionate to the trouble and expense it would entail on him, since the number of persons who would have been willing to become pupils in a school of comparative anatomy was in those days extremely limited. This was probably the chief reason which weighed with him in determining to abandon his scheme ; but we may gather, from the following anecdote, that he was also in part deterred by the difficulties of the undertaking itself. Hunter was one morning at breakfast, when a young man, who was on intimate terms with him as a friend and pupil, mentioned, as if casually, that he had some thoughts of giving a course of lectures on comparative anatomy. Hunter looked up, and drily replied, " Sir, that is a bold undertaking ; I had thoughts once myself of doing the same thing, but the difficulties and necessary qualifications were so great that I do not think myself competent to the task: but you, I dare say, may feel yourself quite equal to it." In the early part of this year Sir C. Blagden presented to the Royal Society the details of some interesting experiments instituted by Dr. Fordyce, himself, and others, to ascertain how far the living body possesses the power of maintaining its standard heat when exposed to air at high temperatures. This drew from Hunter a valuable paper on the heat of animals and vegetables, containing an account of various experiments made some years before,* by which the counterpart of the above proposition was proved, namely, that living bodies possess a power of maintaining their heat against

* Hunter's experiments were made with a view to discover if it were possible to restore to life animals which had been frozen. This was for some time a favourite inquiry, and he used to speculate on the possibility of freezing human beings, and thawing them to life two or three centuries after, a project which, if he could realize, he expected would make his fortune. Whilst his friends Lynn and Benjamin West, therefore, were warming themselves with a bout of skating on the Serpentine, Hunter staid at home freezing his fingers in pursuit of this his philosopher's stone. THE LIFE OF JOHN HUNTER. 47 the influence of external cold, and this in a degree proportioned to their rank in the scale of organization. In January 1776 Hunter received the appointment of surgeonextraordinary to the King, the first and only one which brought him within the atmosphere of Royalty. In the course of this year he contributed to the Philosophical Transactions a memoir on the means to be employed in the recovery of drowned persons. This paper was drawn up at the request of the Humane Society, then newly established. Its contents are so generally known, that it will be sufficient to remark, that the directions it furnishes are based on sound physiological principles, and still continue to guide the conduct of those who may be called to the assistance of a fellow-creature suffering under this form of asphyxia. He also commenced this year a series of six Croonian lectures, on muscular motion, which he had been appointed by the Royal Society to deliver. In return for the assistance which Jenner afforded him in his pursuits, Hunter was enabled sometimes to give him the benefit of his professional advice, in such cases of difficulty as the former might encounter in his practice. The following letters are of this kind, and relate in part to the treatment of a case of fungus cerebri under Jenner's care.

" Dear Jenner, " 1 don't know any one I would as soon write to as you. I do not know any body 1 am so much obliged to. I thank you for a fish, but I should thank you more if you had let me know who it comes from. " I beg for the future you will always write when you send me anything. Somebody sent me a cheese, with a fish upon it; perhaps it was you; you know I hate to be puzzled. Also let me know what things you have sent me lately. I have not received the cuckoo's nest yet. Now for your patient. I believe the best thing you can do is to do little. I would not touch the fungus with an escharotic, for fear the brain should be near: I would also use but very slight compression, as the fungus will be a bandage to the brain ; and as to the fungus itself you have nothing to fear, for wherever the parts underneath are sound, the fungus will subside of itself. Keep your patient rather low, and quiet. Let me know how he goes on, and anything else you can. "Ever yours, J. H." "Dear Jenner, [Post-mark, Jan. 10/A.] " You must think me very fond of fish when you send me cheese as much fishified as possible: however, it is an excellent cheese, and every country has laid claim to its birth. The fish is called----* " I have but one order to send you, which is, to send everything you can get, either animal, vegetable, or mineral, and the compound of the two, either animal or vegetable, mineralized. "1 would have you do nothing with the boy but dress him superficially : these funguses will die, and be damned to them, and drop off. " Have you large trees, of different kinds, that you can make free with ? If you have, 1 will put you upon a set of experiments with regard to the heat of vegetables. " Have you any eaves, where bats go to at night? If you have, I will put

* There is an omission here, which Hunter probably intended to supply before closing his letter, but forgot to do so. 48 THE LIFE OF JOHN HUNTER. you upon a set of experiments concerning the heat of them at different seasons. I should have been extremely happy to have had the honour of a visit irom i.ora Berkeley. "Ever yours, John Hunter. " Anny sends her compliments, and thanks you for all favours. Write down the case."

" Dear Jenner, [Post-mark, Jan. 22rf.] " I did not understand that the funguses which you described were brain ; and I should still very much doubt that they are brain, for their keeping into one substance would make me inclinable to believe that it is a new substance ; but let it be what it will, I would advise you not to meddle with it: if it is brain, let it drop off; if it is fumnis, let it either drop or waste off: therefore be quiet, and think yourself well off that the boy is not dead. You do not mention a word about bats. I have no particular experiments at present about fixed air; it is such a wide field that a man may make a thousand experiments before he determines anything. Have you got the bones yet of a large porpoise? I wish you had. Is ever the salmon spawn seen after she has parted with it? If it is, 1 wish you could get some: I want to examine the spawn of fish in the progress of the formation of the young one. 15 " I am, dear Jenner, your most obedient Servant, John Hunteu.

In the second of the preceding letters we have seen that Hunter expresses a wish that Jenner would undertake some experiments on animal and vegetable heat. This was a subject in which Hunter was much interested, and about which he continued for several years to institute experiments. The following letters, which appear to have been written early in this year, refer chiefly to this inquiry.

" Dear Jenner, "I received the box; also your letter. I am very much obliged to you for your kind attention to me, and how to rewaid you I do not know. Let that be as it will, I must still give you commissions. If you can get me easily salmon spawn, I should like to have it, and out of different places, as it will be of different ages. It should be put into bottles immediately, with spirits. The spirits should be proof, and there should be rather more spirit than spawn. " I will also take any specimens of fossils you may send me, or indeed anything else. Did I send you any of my publications in the Philosophical Transactions? If I have not, let me know. I want to put you upon some experiments this winter. What do you think of examining eels ? Their sexes have not yet been found out, nor their mode of propagation ; it is a thing of consequence in natural history. I began it, but could not get eels immediately from the river, and to get them of fishmongers, who buy them in custom, does not do. My intention was to examine several pretty large eels on the first and fifteenth of every month. If the eels are plenty with you, and if you like the proposal, let me know, and I will give you full instructions how to proceed. Also, next spring, I would have you make the experiments on the growth of vegetables; and if you have no objection, 1 will set you upon a set of experiments upon the heat of vegetables in the winter. If, in any of these pursuits, you discover any principle worthy of the public, I will give it to the Royal Society for you. I must pick you up a picture this winter. 1 saw Mrs. Black* at Mr. Drummonds: I suspect Mr. Black is dead, but I durst not inquire. Cannot you get me a large porpoise for love or money ? What is the bird you sent me ? also the young animals, which I imagine to be guinea-pigs ? "Ever yours, John Hunter." * Jenner's elder sister. THE LIFE OF JOHN HUNTER. 49 " Dear Jenner, "I received your salmon, and very fresh, and just examined enough to want another, but will wait till another season. If I was to have another, it should be one that had just spawned : I will take a cock salmon when yo'u please. If you catch any bats, let me have some of them ; and those you try yourself, open a hole in the belly, just size enough to admit the ball; put the ball down towards the pelvis, and observe the heat there; then up towards the diaphragm, and observe the heat there ; observe the fluidity of the blood. Do all this in a cold place. Extraneous fossils are all vegetable and animal substances found in a fossil state. See if you can catch the number of pulsations and breathing in a bat without torture. If the frost is hard, see what vegetables freeze : bore holes in large trees, and see whether the sap runs out, which will show it is not frozen. 1 am afraid you have not a proper thermometer: I will send you one. " Your very much obliged Servant. J. Hunter. " I have not seen Dr. H., but I dare say he will be glad to have the cases."

The two foregoing letters appear to have been written in January or February. Hunter, in the multiplicity of his engagements, forgot to send the thermometer he had promised, and Jenner, after waiting for some time, began to fear lest he might in some way have offended his friend, and accordingly wrote to inquire the cause of his long silence. To this Hunter "replied in the following letter, which bears the post-mark of April 12th.

" Dear Jenner, " I can never be offended with you. The reason for not sending the thermometer was I entirely forgot it, but it shall be sent next week. I shall be glad to present your paper if you mean to give it to the public. The large porpoise I would have coarsely stripped, and the bones put into a cask and sent; the young one, if not too large, put into spirits to be able to inject it. If the breasts of the old one were taken off and put into the cask among the spirits, I should like it. You will find the nipples on each side of the vulva, and the gland passes along under the skin of the belly, almost to the breast, so that it would be only preserving the belly part. Did I write to you some time ago about cuckoos ? I have forgot: if I did not, I must give you a long order. "Friday night. I am, dear Jenner, ever yours, J. Hunter. "I was at my club last night, and not coming home till twelve is the reason I did not write."

" Dear Jenner, [Post-mark, April \Qth.] "I have received ^your fish, as also your letter; for both I thank you. It came quite fresh, and it. is under dissection and drawing. The bubbies of this are as flat as a pancake, but I have injected the ducts. Was the milk sweet ? Could you save some of it? if but two drops, to see if it grows sour. Try it with the syrup of violets. Are the breasts demolished ? Are the kidneys demolished ? If not, could you send them ? I will leave it to you what is to be done at present with the bones ; either send them as they are, or steep them in water till the flesh rots off. If you could, send me the stomach and a piece of intestine, if the largn one was different from the small; but if it had the same head, then you need not send them, as the present informs me of the class. I have got the thermometer, but let me know to whose care I am to send it. You did not in your last tell me if I wrote to you about the cuckoo. " Ever yours, J. Hunter.'

Very soon after the date of the last letter, Hunter was attacked with an alarming fit of illness, brought on by anxiety of mind, at being called on to pay a large sum of money for a friend, for whom he had become security; a call which his circumstances made 50 THE LIFE OF JOHN HUNTER. exceedingly inconvenient. The most distressing feature of this complaint, which Sir Everard Home has described at considerable length, was a constant vertigo, which rendered him incapable of raising his head from his pillow for ten days: this sensation was accompanied by a morbid acuteness of the organs of sense, with a feeling of being suspended in the air, of his body being much diminished in size, and of every motion of the limbs or head, however slight, being both very extensive and accomplished with great rapidity. This complaint was unattended by fever. Various remedies were employed, but without any perceptible effect on the symptoms, which, at the end of ten days, began to disappear spontaneously. Sir Everard Home dates this illness in 1776; but in one part of his memoir he says it happened in the spring, and in another in the autumn. The following letter of Hunter's to Jenner, which, contrary to his usual practice, bears the date of the year, shows that it occurred in 1777.

" Dear Jenner, " I have before me two letters of yours, which I should have answered much sooner. Your friend Dr. Hicks I have not seen. I was not at home when he called, and I have not had time to wait on him, as he lived entirely out of my walk. I should have been glad to have seen him, but I suppose he stood upon ceremony. I received the fossils, and should be glad of any that you can get. If any bones of animals are found, be sure and get them for me. I should be glad to have some of the salmon-fry. I had the pleasure of seeing your brother, but only for a time. I received the bird : I am not acquainted with it: send me some more if you can get them readily. I sent with Mr. Jenner the thermometer: if you do not understand it let me know. " Not two hours after I saw your brother I was taken ill with a swimming in my head, and could not raise it off the pillow for ten days : it is not yet perfectly recovered. Have you begun the eels ? No porpoises. No salmon spawn before it has hatched. You see I am very greedy. Be sure to keep an account of all outgoings. "My compliments to Mrs. Black and your brother, and let me hear from you. " Ever yoius, J. Hunter." "London, May 11, 1777.

In July he wrote again to Jenner, explaining the mode of using the thermometer, and treating of divers other matters, with his accustomed brevity.

" Dear Jenner, " Excuse me for not answering your letters as soon as you could wish. Send me all the fossils you find. What I meant by bones was all the bones that are found any depth below the surface of the earth : many are found in stones, &c. I suppose those skeletons are not complete, but send me eome of them • and if any history can be given, send it also. The thermometer is a very useful one when understood. You will observe the scratch upon the glass stalk, perhaps about two inches from the globe, which is the freezing point: put 0, or nought, which is upon the ivory scale, two degrees below the" scratch, thenO becomes the thirtieth degree, and the scratch, being two degrees above it, stands at the freezing point; then, from that count upwards : or if the cold is below 30° then put 1 or 2 at the scratch, and count down : every No. is ten degrees. What the devil becomes of your eels in the winter? but try them in summer, and see what you can make of them. " I do not remember Dr. Fordyce's ever supposing a polypus vascular. I THE LIFE OF JOHN HUNTER. 51 should rather believe that he supposed the contrary : you know it comes near my idea that the blood is the bond of union everywhere. But I should very much suspect that a polypus formed after death is not of that kind. I am pretty certain that I have injected them in arteries after amputation. 1 have a preparation which shows it, and which supports my theory. Yours, " London, July 6th, 1777. J. Hunter."

Hunter was disposed to treat his late illness as one of trifling moment; but his medical friends thought more seriously of it, and as he had never fully regained his health, urged his resigning business for a time and retiring to Bath. In compliance with this advice, he proceeded thither in the autumn, after having deputed Mr. Bell and Mr. Home, in his absence, to complete a catalogue of all the preparations in his museum with which they were acquainted, a task which had been hitherto entirely neglected. Before leaving London he announced to Jenner his intended visit to Bath in the following letter.

" Dear Jenner, August 6th, 1777. " I just now found your last letter. I think I answered it, but am not sure; if I did not let me know. Is there any judging whose these human bones are ? Let us have some of them, especially skulls, as complete as possible, with the lower jaw, &c. 1 am very well, but for all that I set out, in a few days, for Bath. " Ever yours, J. Hunter."

Soon after his arrival at Bath he was visited by Jenner, who was greatly shocked to perceive the alteration which had taken place in his appearance, and concluded, from the symptoms under which he laboured, that his disease was angina pectoris, an affection not then well understood, but which Jenner had been led to believe, by the dissection of former cases, depended on an organic change in the heart. He abstained from telling Hunter his opinion, as he feared the effect such an announcement might have on his mind, but communicated it to Dr. Heberden, one of Hunter's medical advisers, in a letter, which Dr. Baron has published in his Life of Jenner. During the time Hunter remained in Bath he appears to have had frequent communication with his friend, and the following letter affords a good example of the familiarity which existed between them.

"Dear Jenner, "Till yesterday we did not know from whom the hare came; but the cook found it out. We thank you : it was a very fine one. By your not taking any notice of my letter, I do suppose you did not receive it. Near three week3 ago I wrote to you to meet us at the Hotwells, Bristol. Some days after the date of my letter we went to the place appointed, by ten o'clock in the morning; but no Jenner there. We breakfasted, we dined, we staid all night, and set out for Bath the next day. We would have come on to Berkeley, but we were afraid you might not be there. I am afraid it will not be in my power to come and see you, though I wish it much. I shall be obliged to take Southampton in my way home. Are the hedgehogs so saucy as to refuse coming without coming for them? See if you can coax them. We are alive here. The downs look like a beehive. Let me hear from you. Mrs. Hunter gives her compliments to you. "Bath,\8lh. Yours, J. Hunter." " My letter was sent to your friend in Bristol by the coach, but perhaps the coachman forgot to deliver it." 52 THE LIFE OF JOHN HUNTER. After remaining three months in Bath, he became very desirous to be at home again, and decided therefore on immediately returning to London, though his health was not fully re-established. Fortunately, he felt no inconvenience from this step, but continued to improve after his return, and shortly regained his usual state of health. He now recommenced his ordinary pursuits with unabated diligence, and appears about this time to have been chiefly engaged in confirming and extending his inquiries on vital heat. He was anxious to engage Jennet's assistance in conducting some of the experiments, for which his residence in the country afforded him the necessary facilities, and determined to write to him on the subject; but as he had received no reply to several of his late communications, his first letter was written to inquire the cause of Jenner's long silence.

" Dear Jenner, " I wrote to you twice from Bath since I saw you, and have had no answer to either; what the d—1 is become of you ? I have got your candlesticks: to where shall I send them? Let me know by return of post; and all the news you can. Yours, " Nov. 6th, 1777. John Hunter."

Having ascertained, to his satisfaction, that Jenner had not become a subject of " Pluto's dreary reign," he forthwith transmitted him the necessary instructions for his guidance.

" Dear Jenner, " I have sent you the candlesticks as you desired. I hope you will like them. They cost five pounds and a shilling; so I owe you four shillings. I have received the hedgehogs. If you have time, see their natural winter haunts, and in the very cold weather run the thermometer into the anus, and observe the heat; then open the belly by a shall hole, and pass the thermometer down towards the pelvis, and observe the heat; then towards the liver or diaphragm, and observe the heat: you may do all this in a very few minutes. Observe the fluidity of the blood, by comparing it with another that has been kept warm for a few days. I have heard of Mr. Cattgal's collection of fossils, and not till I came to London : I suppose he will not sell any. I shall think of your lymphatics ; and if I can pick up a preparation or two, I will. I am sorry you did not get my first letter, as we intended going to Berkeley with you, but did not choose to come without an answer, as it was possible you might not be at home. I have seen your old master, who has given me the use of a very curious bone : I hope he will give it me altogether. Dear Jenner, yours, " Nov. 23d. John Hunter."

Unfortunately, his hedgehogs all died, either from exposure to cold or some other cause; he therefore referred the experiments, for the present, to Jenner, until he could learn what means were requisite to keep them alive.

" Dear Jenner, " I am always plaguing you with letters, but you are the only man I can apply to. I put three hedgehogs in the garden, and put meat in different places for them to eat as they went along; but they all died. Now I want to know what this is owing to; therefore I want you to find out their haunts, and observe, if you can, what they do ; if they make a warm place for themselves; if they have THE LIFE OF JOHN HUNTER. 53 any food by them, &c. I would have you kill one, and see its heat. First, make a small hole in the belly, and introduce the thermometer into it, first down to the pelvis, then up to the liver and diaphragm, and see the difference, for I believe they will answer the purpose as well as bats. See if there is any food in the stomach ; what the intestines contain; examine if they are fat, and in the spring see if they are much leaner; see if the blood is as fluid as common, or if thicker. In short, make what observations you can. Let me hear from you when you have nothing else to do. Yours, "London, Dec. 17. J. Hunter."

His next letter, written in March 1778, is as follows:

" Dear Jenner, " Your letter of December has lain before me ever since I received it, to put me in mind that it was not answered. I am glad you liked the candlesticks : I thought them pretty. The fossils were none of the best; but 1 know you did not make them, therefore it is not your fault. The particular one you put the Q? on is only the cast of a bivalve. I wish I had seen E.'s collection. I am matching my fossils, as far as I can, with the recent. Have you made any experiments with the hedgehogs, and can you send me some this spring? for all those you sent me died, so that I am hedgehogless. " Mr. Ludero sent me the bone; it is a very curious one: whether he will let me keep it or no I do not know. I received yours by Mr. Jones, with the bird. I thank you for thinking of me. Frogs live an amazing while after they are dead ; as also all animals of that tribe. The directions I gave you about the blackbirds were, when you have a blackbird's nest, viz. with four young ones, take one and put it bodily into spirit by the head, extending the wings and legs. Observe when the feathers begin to sprout; then take another, and serve it in the same way; then a third, and a fourth, so as to get a series of the growth of the feather; but the last, or fourth, must not be so old as the feathers to cover other parts where feathers do not grow. This you will better understand when you come to make the trial. I have a picture of Bassan's that I lent a poor devil three guineas upon : he died and never redeemed the picture. I intend sending it to you: it is a good deal damaged, but some of the figures are very good. Get a frame for it, and hang it in a strong light. There are some experiments of mine publishing in the Philosophical Transactions, which I will send you with the picture; accept them as a remembrance of the trouble I put you to. Let me hear from you when convenient. Mrs. Hunter desires her compliments to you. " I am, dear Jenner, your most obedient and most humble servant, "London, March 29, 1778. John Hunter."

It is not very clear what are the experiments to which Hunter alludes in the foregoing letter as about to be published; it seems most probable, however, that they were those contained in his second memoir on the heat of animals and vegetables, which he this year presented to the Royal Society. The only ground for doubting it is, that at the head of this paper, in the Transactions, it is stated to have been read in part on the 19th of June, and the remainder on the 13th of November, whereas the date of the foregoing letter is March. This was one of the most valuable of the many excellent papers which Hunter furnished to the Royal Society, both on account of the importance of the subject treated of, and the valuable deductions he has drawn from his experiments. The inquiry was both new and complicated, and it is not therefore surprising, that whilst adding much to what was before known on the subject, he yet left some errors to be corrected, and many parts requiring to be ex- 7 54 THE LIFE OF JOHN HUNTER. tended and filled up by the labours of later physiologists. Hunter never contented himself with the character of a mere maker of experiments, but alwavs aimed at drawing general conclusions; and he perhaps occasionally fell into the error of generalizing from insufficient data. Hence we find that on the present subject his experiments are sometimes not sufficiently varied, and are defective, for want of those precautions against disturbing influences which characterize the inquiries of Edwards, Marshall Hall, and other physiologists, who have of late trodden in the same path. Hunter does not seem to have considered his own inquiries on the subject as at an end, for he recurs, in many of his letters written after this time, to his experiments on hedgehogs, as the following letter written about this time, evinces.

" Dear .Tenner, "I received yours by Dr. Hicks, with the hedgehog alive. I put it into my garden : but I want more. I will send you the picture ; but by what conveyance ? or by what place? I have a picture by Barrett and Stubbs. The landscape by Barrett; a horse frightened at the first seeing of a lion, by Stubbs. I got it for five guineas : will you have it ? I have a dearer one, and no use for two of the same masters; but do not have it excepting you would like it, for I can get my money for it. "1 am glad you have got blackbirds' nests. Let me know the expense you are at, for I do not mean the picture to go for anything, only for your trouble. " Ever yours, J. H. " N. B. I should suppose the hedgehogs would come in a box full of holes all round, filled with hay, and some fresh meat put into it."

Jenner had, about this time,become involved in an affaire du casur, which, unfortunately, ended in disappointment. Hunter had heard a rumour of his expected marriage, but not of the rejection of his addresses; and in his next letter expresses his hopes that his information may prove to be correct.

" Dear Jenner, " I don't know what I wrote to you last. I do not know if I thanked you for the cider. The hedgehogs came, with one dead, which was a female with young, and which I made a preparation of. I have since got the blackbirds, which I think will do vastly well. I have not yet sent the picture; it is packed up ready to go, and shall be sent immediately. " I was told the other day that you was married, and to a youno- lady with considerable fortune. I hope it is true, for I do not know anybody more deserving of one. Let me know whether it is so or not. I hope you keep an account of all expenses. What is become of your paper on lead in cider ? Let me have it, and I will send it to the Medical Society. How do the fossils go on ?

Jenner was of a rather sensitive disposition, and as he had probably calculated pretty certainly on success in his suit, was much affected for some time by the disappointment. Hunter was moreover, not exactly the person " to trust a love tale to," and Jenner accordingly delayed to reply to his inquiries until the receipt of the following letter, which requiring an immediate answer, he summoned courage to communicate the real state of affairs.

" Dear Jenner, [Post-mark, Aug. 30 1 "I hope this winter to be able to get you some preparations oftheeye'and THE LIFE OF JOHN HUNTER. 55 lymphatics ; but Hewson's preparations are to be sold this month ; now perhaps for four or five pounds some preparations may be picked up. If you have no objection to throw away so much money, let me know, and what subjects you would like best. I shall give you some commissions about heat, cold, &c. Yours, John Hunter."

On learning how Jenner's hopes had been frustrated, Hunter kindly expresses his regret, but, as might be expected, recommends to the lover a summary dismissal of the lady from his memory, and like a skilful physician, undertakes to find him other employment for his thoughts.

" Dear Jenner, "I own I was at a loss to account for your silence, and I was sorry at the cause. I can easily conceive how you must feel, for you have two passions to cope with, viz., that of being disappointed in love, and that of being defeated; but both will wear out, perhaps the first soonest. I own I was glad when I heard you was married to a woman of fortune; but ' let her go, never mind her.' I shall employ you with hedgehogs, for I do not know how far I may trustmine. I want you to get a hedgehog in the beginning of winter, and weigh him; put him in your garden, and let him have some leaves, hay, or straw, to cover himself with, which he will do ; then weigh him in the spring, and see what he has lost. Secondly, I want you to kill one in the beginning of winter, to see how fat he is, and another in spring, to see what he has lost of his fat. Thirdly, when the weather is very cold, and about the month of January, I could wish you would make a hole in one of their bellies, and put the thermometer down into the pelvis, and see the height of the mercury; then turn it upwards, towards the diaphragm, and observe the heat there. So much at present for hedgehogs. I beg pardon,—examine the stomach and intestines. If Hewson's things go cheap, I will purchase some that I think proper for you ; those you mention will, I am afraid, be everybody's money, and go dear. Ever yours, "London, Sept. 25th, 1778." J. Hunter."

Hunter's next letter is dated in November, and relates chiefly to the physiological experiments which he had requested Jenner to make, and to another inquiry respecting the breeding of eels, to which he had directed Jenner's attention in a former letter.

" Dear Jenner, London, Nov. 9, 1778. "I received yours, with the eel. The spawn of the salmon was lost. I shall send you hack the eel again, with the liver, stomach, and gut removed, and nothing left but a fringe which passes down the sides of the backbone, which I took, and still take to be the spawn; but I never saw any difference in it at any time of the year; and this one you have sent is similar to all I have yet seen. I think your stopping the eels a good plan, if you can ; but I should suspect they would ne more slippery than hedgehogs. I do not know if hedgehogs burrow. About a month hence examine another, and compare him with your notes and memory also. Examine his heat in the pelvis, diaphragm, &c.; a month after that another, &c. I like your experiment on the toad and snake; but bury them rather deeper, and let the ground be kept moist about them, especially in summer. I shall keep all your letters, but I expect in the end all your notes. I like your friend Ludlow much ; he is a lively sensible fellow. I have got a few preparations for you ; I am getting them put into a little order for you before 1 send them. Are there no bats in the old castle of Berkeley ? I should like similar experiments to be made upon them to those of the hedgehog. Mrs. H. desires her compliments to you. " Believe me to be, most sincerely yours, John Hunter."

Hunter this year completed his work on the Teeth, by publishing 56 THE LIFE OF JOHN HUNTER. the second part, containing an account of the disease which these organs are liable. Mr. Home had now resided six years with Hunter, in which time he had completed his education; and as he had no emoluments to expect by remaining longer an inmate of his house, since, says he, " his expenses had always hitherto exceeded his income," he was glad to obtain the very eligible appointment of surgeon to the new naval hospital at Plymouth, where he was immediately called on to take charge of the men who had been wounded in the late action under Admiral Keppel. It may seem surprising, that after having been so long in practice, and after acquiring so considerable a reputation as Hunter at this time enjoyed, his finances should still have been in an embarrassed state ; but it must be remembered that Hunter had for some years past maintained his two establishments in London and at Earl's Court; to supply the wants of an increasing family, and, what was probably most expensive of all, to provide for the outlay required for the maintenance and extension of his museum. Mr. Hunter once declared to Mr. Lynn that the museum had cost him upwards of 70,000/.; and when it is recollected that the whole of his professional income, which for the last ten years of his life was very considerable, was, with the exception of his domestic expenses, wholly devoted to this object, we canAot doubt that this estimate was near the truth; at least the sum of 15,000/., voted for its purchase by Parliament, fell very far short of the actual outlay, to say nothing of the time and talent unceasingly devoted by himself and others to its completion. Rarely, however, have the labours of those great men who have advanced before the age they have adorned been duly appreciated, until another generation has arisen to weigh their merits in an impartial balance. THE LIFE OF JOHN HUNTER. 57 CHAPTER V.

Mr. Hunter's paper on the hermaphrodite black cattle;—his anxiety for rare specimens to enrich his museum;—renewal of the disagreement between him and his brother.—Mr. Hunter's paper on small-pox during pregnancy;—his paper on the hen pheasant.—Trial of Sir T. Boughton.—Croonian lectures.— His paper on the organ of hearing in fishes;—removes to Leicester square;— assists in forming the Society for the Improvement of Medical and Chirurgioal Knowledge.—Charlatanism.—Correspondence.—Mr. Hunter's notion of the immateriality of matter from the theory of colours;—his paper on the inflammation of veins;—his fame and practice at this time;—his merits as an operating surgeon;—his illness returns ;—his second visit to Bath;—Mr. Home acts as his assistant.—Mr. Hunter's paper on the double-coned Terebella;—his operation for popliteal aneurism;—is appointed Deputy Surgeon-general to the Army;—his Treatise on the Venereal Disease;—his work on the Animal OEconomy;—prints his own works at his own house ;—his paper on the Wolf, Jackal, and Dog;—his paper on Whales.—The giant O'Brien.—Obtains the Copley medal;—opens his museum to the public.—Mr. Home and Mr. Keate appointed assistant surgeons at St. George's Hospital.—Sits for his portrait to Sir Joshua Reynolds.—Sharpe's engraving.—Death of Pott;—comparison between him and Hunter.—Pott's character.

In 1779 Hunter's valuable memoir on the hermaphrodite black cattle, or free martin, was read before the Royal Society.* As usual, he has by no means confined himself to a bare anatomical description of the peculiar malformation of the genital organs in these animals, but has introduced the subject by a variety of observations on hermaphroditism in general, which render his paper a very important contribution to this branch of physiology. It will be remembered that in his last letter to Jenner, Hunter had requested him to make some further experiments on the heat of the hedgehog during its torpid state. He had as yet received no com-

* Amongst those present at the reading of this paper was the illustrious anatomist Von Soemmerring, then a young man, as the following letter, written by him on his being elected a Fellow of the Royal Society, will show : " Franfurt am Mayn, 20th August, 1827. "Dear Sir,—Feeling myself extremely honoured in being admitted as a foreign member by the very first literary Society in the world, I beg the more from you the favour to return my best and sincerest thanks, as I always remembered with singular pleasure to have been present in the year 1788, at the reading of John Hunter's celebrated paper on the free martin, not imagining at that time once to become myself associated to that illustrious assembly, by whose exertions I profited infinitely in all my studies. I am, dear Sir, with great respect, your obedient humble Servant, Samuel Thomas von Soemmerring, F.R.S., Privy Counsellor to H. M. the King of Bavaria, Knight of several I. and R. Orders. To Dr. Young, Foreign Secretary of the Royal Society." 7* 58 THE LIFE OF JOHN HUNTER.

munication on the subject, and accordingly wrote the following short note, as a spur to his friend's activity.

" Dear Jenner " What are you doing? How do the hedgehogs get on ? How cold are they in the winter? &c. &c. Let me hear from you. I have not yet sent the preparations for you. I have added an eye to one of them of my own making. ^ "London, Jan. 16, 1779. Yours, J. Hunter.

Jenner had not been idle, however, but was able to give so good an account of his proceedings that Hunter seems to have resolved not to allow so valuable a coadjutor to remain unemployed; accordingly, though he rarely put confidence in any experiments which were not conducted by himself, or under his own eye, he suggested to Jenner some further ones, respecting the state of the digestive powers during torpor.

" Dear Jenner, " I thank you for the trouble you have taken. I do not see another experiment to he made with the hedgehogs, but one: get a piece of meat into the stomach of one, during the very cold weather, and kill him twenty-four hours after, to see if it is digested, which I have done with lizards. This may be difficult; hut suppose he was made lively in a warm room, and then fed, and put out into the cold immediately, with a little hay over him. If this does, two or three may be served in the same way, and kill them at different distances, respecting time. Observe their breathing when in the cold ; if possible, the quickness of the pulse and fluidity of the blood. If you chance to get more than you use, I would take a few to put into my garden, to walk about in the evenings. "Is there no chance to see you in London this winter? Do come and see us. I shall send you a paper of mine on the free martin, also one to Ludlow. I wrote to him in answer to his letter; I hope he received it. If a good deal of that air in the hog's guts could be collected, see if a candle would burn in it as large as in common air. I had a letter from Mr. Cheston, of an ossified thoracic duct; I wish he would let me have it: you see how greedy I am. You will hear from me soon. " Ever yours, John Hunter."

The above letter furnishes an example of the eagerness with which Hunter sought to draw all curiosities connected with his researches within the sphere of his museum. He was indeed a most resolute beggar for every specimen which particularly pleased him by its rarity, and which chanced to be in the possession of any of his friends. The late Dr. Clarke had a preparation of an extra-uterine pregnancy, in which the foetus had been detained in the fallopian tube, and had there undergone partial development, when the mother died from internal hemorrhage, consequent on the rupture of the tube. On this specimen he set a high value, and Hunter had often viewed it with longing eyes, " Come, Doctor," said he, " I positively must have that preparation." " No, John Hunter," was the reply, " you positively shall not." '; You will not give' it me, then V " No." " Will you sell it ?" " No." « Well then, take care I don't meet you with it in some dark lane at night, for if I do, I'll murder you to get it." Winter returning, brought back Hunter's thoughts to his inquiries THE LIFE OF JOHN HUNTER. 5g

on vital heat, and we find him accordingly writing to remind Jenner to prepare for fresh operations against the hedgehogs.

" Dear Jenner, " I have not troubled you with any letter this long time, nor have I heard from you. This moment, I do not know if I sent you the butterflies ; if they are not sent, they shall this week. I want you to pursue the experiments on the heat of the hedgehog this winter ; and if you could send me a colony of them, I should be glad, as 1 have expended all I had, except two : one an eagle ate, and a ferret caught the other.* Mrs. Hunter and I were at Bath the other day, and came home by way of Gloucester; we wished much we could have staid a day, to have waited on you. Let me hear from you soon. I am, dear Jenner, yours, "London, Nov. Slh, 1779. John Hunter."

In 1780 that unfortunate disagreement took place between the Hunters, of which mention has been made in a former part of this memoir. It commenced in John Hunter's presenting to the Royal Society a paper on the structure of the placenta, in which he claimed for himself the honour of discovering the true mode of union between this organ and the uterus, a discovery which Dr. Hunter had communicated as his own, in his work on the Gravid Uterus. What could have induced Hunter to bring forward such a claim twenty-five years after the alleged discovery, and five years after the publication of Dr. Hunter's work, it is not easy to say. The probable explanation seems to be, that something unpleasant had previously passed between the brothers, and that, under a consequent feeling of irritation, Hunter transmitted his paper to the Royal Society.f Whether his claims were well or ill founded ; whether any part of the discovery was his ; or what it was, it is impossible, from the evidence now before us, to decide. Dr. Hunter, in a letter to the Royal Society, denied having derived his information from his brother, and asserted that the discovery was the result of manv years' patient investigation of the subject on his part.J To this a

* Hunter's account of his hedgehogs reminds one of Magendie's remark on the dogs whose evil stars bring them acquainted with the interior of his physiological slaughter-house. " Vous savez, Messieurs,'''' said the Professor to his class, " que les chiens ire s^amusent pas i'cj." f Such an explanation has, in fact, been commonly given, but the causes assigned have been various. Some confidently allege that Hunter's resolute determination to marry Miss Home gave offence to his brother, who strongly remonstrated against his forming an alliance with a lady who had neither rank nor fortune, which, he asserted, would slacken his endeavours after fame, and mar his fortune. By others a dispute is said to have occurred between them respecting certain preparations, now in the Hunterian Museum at Glasgow, to which both brothers laid claim ; but through the inquiries of Professor Badham, who has kindly investigated the subject, it has been shown that no jus^grounds for this account exist, although such a tradition has certainly prevailed on the spot. It is needless at this time to scrutinize further into so unpleasant an affair, although it was one which probably affected Mr. Hunter's feelings more powerfully than any other event of his life. % Letter I. " Windmill Street, Feb. 3, 1780. " Dr. Hunter begs the favour that the Secretary to the Royal Society will read to the Society what follows. "Mr. Hunter's account of the structure of the human plaeenta, explaining 60 THE LIFE OF JOHN HUNTER. rejoinder was sent by Hunter, reasserting the truth of the account he had given of the "transaction, but adding that as his brother seemed unwilling to allow him the whole merit, the former should

the connexion and circulation between the mother and the foetus in utero, which was read at the last meeting of the Royal Society, informs us that it was a discovery which he made with Dr. Mackenzie, and that it was not claimed by me. The Society will be sensible that I am reduced to the necessity of taking notice of this mistake, when they are informed of the following facts : " First. That the doctrine has been many years ago published in printed books as my discovery, and had been communicated as such by myself. See Baron Haller, for instance, in the second part of the eighth volume (p. 220) of his great Physiology, in quarto, printed thirteen or fourteen years ago. "Secondly. Besides treating of it as my own discovery, in my lectures upon the subject, I have always done so for many years last past, in the very first lecture of my course, which is the most public of all, because the door is then open to every person whose curiosity prompts him to be present. "In the third place, occasionally both in what I have printed, and in my lectures, I hope I have not overlooked opportunities of doing justice to Mr. Hunter's great merits, and of acknowledging that he had been an excellent assistant to me, in this and in many other pursuits. By doing so I always felt an inward gratification, shall I call it, or pride? I had given him all the little anatomical knowledge which I could communicate, and put him into the very best situation that I could for becoming what this Society has for some time known him to be. May it be presumed, then, that I stand possessed of the discovery in question, till proofs shall be brought to dispossess me ? I shall most willingly submit to the pleasure of this Society. If they signify an unwillingness that this emulation (I will call it) should go on, I shall acquiesce, and be silent. If curiosity, justice, or the laws and practice of the Society should incline the Council to seek out and determine upon the merits, I shall be equally ready to obey their commands. And if it should appear reasonable to them, I would first beg to know the grounds of Mr. Hunter's claim, as I am too well acquainted with his abilities not to think that he must be able to support his claim by something that I am ignorant of. And if I should receive that satisfaction, I shall immediately show that I am more tenacious of truth than even of anatomical discoveries. But if that information should not alter my thoughts upon the question, I shall show to the satisfaction of the Society, if I can at all judge of my own employments and pursuits, that my pretensions arise out of a long series of observations and experiments, made with a view to the discovery in question : that it was not a random conjecture, a lucky thouaht, or accidental occasion, but a persevering pursuit for twelve or thirteen years°at least, the progress of which was always publicly known here, and admits of the most circumstantial proof. William Hunter."

" To the President of the Royal Society.

"Sir, Jermyn-street, Feb. 17, 1780. "Though I know the constitution of the Society over which you preside too well to suppose that they will give their judgment on any subject, and respect it too much to think it a proper field for waging the war of controversy I cannot avoid requesting you to lay before that learned body a short answer to the paper given in by my brother, Dr. Hunter, as silence on my part, after his charge may be interpreted by my enemies into an acknowledgment that I have intentionally claimed to myself a discovery in reality his due. I am as tenacious as he is of anatomical discovery, and, I flatter myself, as tenacious, also, of truth The discovery was made in the manner in which I stated it in my paper Dr Mackenzie had injected the subject, and being unable, as I conceived, to explain an appearance which he had found in dissecting it, sent for me. I came to him THE LIFE OF JOHN HUNTER. 61 be welcome to share it, provided that a part at least of the discovery was adjudged to himself; which, after all, would have probably been the fairest mode of adjusting their claims. Here the discussion terminated. The Royal Society decided to take no further cognizance of the matter, and would not allow the offending paper to be published in the Transactions. Between the brothers, unhappily, the estrangement produced by the dispute continued undiminished until Dr. Hunter was on his death-bed, though to John Hunter at least, if not to both, it was often a cause of deep regret. During Dr. Hunter's last illness, which occurred three years after, his brother requested that he might be admitted to see him: this was acceded* to, and he continued to visit him daily, and to afford him professional assistance until his death. Notwithstanding this apparent reconciliation, the feeling of soreness seems not to have been quite obliterated from the mind of Dr. Hunter, since it did not lead him to make any alteration in the previous disposal of his property, and he died without leaving any portion of it to his brother. Dr. Baillie, however, to whom Dr. Hunter left the family estate, with great generosity ceded it to Mr. Hunter, as soon as the will was proved. Two other papers of Hunter's were read before the Royal Society, and published in their Transactions for this year. The first of these, which was presented in January, contained the account of a woman who had taken the small-pox during pregnancy, and passed safely through the disease, but some weeks after fell into premature labour, and was delivered of a dead child, bearing on its body an eruption precisely similar in its character to the small-pox in an

and having examined it further, explained the appearauce in question, then, for the first time, to my own satisfaction and that of Dr. Mackenzie; and in the evening of the same day, full of the discovery, I came to Dr. Hunter, and brought hirn with me to Dr. Mackenzie, to see and judge of the explanation I had given and Dr. Mackenzie had agreed to. This is my state of the fact upon which I ground my belief of myself being the author of this anatomical discovery; but as my brother thinks differently, after a period of twenty-five years, I am content to abolish all remembrance of the successions of time in the course of that day, and to suppose that Dr. Mackenzie, Dr. Hunter, and myself, inspected the parts together, and made the discovery: by which means the honour of it will be divided into three, one of which I may surely be allowed to take to myself, the other two may appertain to Dr. Mackenzie and Dr. Hunter, if they choose to claim and be content with them ; though in this division we must make some reserve for the claim of several ingenious young men, at that time pupils, who were with us, and, of course, entitled to some proportional share in the discovery, though their present situations, settled at a distance from this town, have prevented them from getting early notice of the present claim, and, of course, of making application to the Society for their share. However, I may here declare, that if Dr. Hunter will produce to me any claim which I can allow of his having discovered this anatomical fact at any period of time prior to this conference at Dr. Mackenzie's, I shall first declare, in excuse for having troubled the Society, that I was not before acquainted with it, and immediately after declare that he is entitled to the sole honour of it, at least in preference to myself. " I am, sir, your much obliged, and most obedient humble servant, John Hunter." 62 THE LIFE OF JOHN HUNTER. advanced stage. To the details of the case are subjoined some valuable cansiderations, suggested by them to Hunter's mind. The second paper contains observations on a phenomenon of not unfrequent occurrence amongst pheasants, and several other species of birds; that, namely, of the hen bird's assuming a plumage like the cock's. This change is found to occur only when the hen has ceased from breeding, and, as Hunter supposed, only when the cessation was the result of old age; but more recent researches have shown, that a disease of the ovary, unfitting this organ for producing eggs, may give rise to the change of plumage even in young hens. The following letter to Jenner, dated 4th of March, appears to have been written this year, and like most of the others, relates chiefly to various objects* of natural history received or expected by him from Berkeley.

" Dear Jenner, "This very evening I was going to write to you, when behold a basket came with pea-fowls, lizards, and birds' legs. I know nothing of the natural history of the viviparous lizard, but shall ask Sir Joseph Banks, who, I dare say, knows ; but I should like to have them when with young, therefore beg you will give a genteel reward to those who will bring you several; and let me know in what situations they are commonly found, that I may employ others to hunt for me. How did the puppy and you agree ? " Last night I looked over all your letters, to see the one giving me the account of the porpoise, but I could not find it; therefore I must beg your account of them, and the milk, &c, which I hope you will send soon. Lord Berkeley has not sent for his dog. Have you had any account of the bustard ? " Monday morning has produced nothing new ; so good day to you. " March 4th. J. Hunter."

In March 1781 Hunter appeared as a witness at the Warwick assizes, in the famous trial of Capt. Donellan, for the supposed murder of his brother-in-law^ Sir Theodosius Boughton. Great public interest was excited by this trial at the time, and the medical evidence adduced en the occasion has furnished subject for comment in almost every English work on legal medicine published since that time. Sir T. Boughton, a young man, previously in good health, expired in convulsions about half an hour after taking a draught of rhubarb and jalap, sent hirn by his medical man, but with which it was supposed Capt. D. had subsequently mixed laurel water, as Sir T. Boughton's mother observed that the draught smelt of bitter almonds. Suspicions of poison were excited, and about ten days after death the body was disinterred, and examined by several medical men, who, however, made but an imperfect inquiry, as they neglected to investigate either the brain or the intestines. At the inquest suspicion fell on Capt. Donellan, who was consequently arrested, and tried at the following assizes. On the trial, four medical witnesses gave it as their opinion, from the symptoms, and the appearance on dissection, that Sir T. THE LIFE OF JOHN HUNTER. 63 Boughton had been poisoned, and that laurel water had been the means employed. Hunter, on the other hand, with that proper caution which resulted from his extensive knowledge, avoided drawing so hasty a conclusion. He asserted that the appearances described as having been seen on dissection, were such as might have arisen from putrefaction alone; and with regard to the symptoms, that they might have been caused by apoplexy or epilepsy as well as by poison, a point which an examination of the head would have gone far to decide. He allowed, on his cross-examination, that the occurrence of the symptoms immediately after taking the draught, was a circumstance in favour of it having caused them; and "if" said he, " I knew the draught ivas poison, I should say that, most probably, the symptoms arose from that." But he very properly, and indeed with the direction of the Court, separated in his mind the circumstantial evidence adduced to show that the draught was poison, from the medical testimony he was called on to draw from the symptoms and dissection: [and having done so, he said he felt it impossible to give any decided opinion as to the cause of death. Mr. Justice Buffer, who presided at the trial, seems to have lost his temper at not being able to draw a more decided opinion from Hunter as to the real cause of death, and on summing up, threw out some sarcastic remarks on the doubts he had suggested, and attached no weight whatever to them. The consequence was, Capt. Donellan was found guilty and executed. The circumstantial evidence against him, indeed, was rather strong, so that we ought not perhaps to consider this, as some have done, an instance of judicial murder: assuredly, however, there was not sufficient ground for conviction, and the conclusions of the medical men opposed to Hunter rested, for the most part, on completely unsatisfactory data, and should have had but little weight in the decision of the question. In 1781 Hunter was elected a Fellow of the Royal Society of Belles Lettres at Gottenburg. In 1782 he completed his series of six Croonian lectures on muscular motion,* of which he had annually delivered one since 1776, with the exception of 1777, when for some reason he * From the following letter of Hunter's to Sir J. Banks, it would seem that he experienced some difficulty in getting paid the money allotted for the support of the Croonian lectures. With whom the fault rested does not appear; but as Hunter was not fond of being troubled about money matters, to cut short the affair he applied to the President. "Jermyn-street, July 25, 1781. " Sir,—The last lecture on muscular motion which I had the honour to deliver was the fifth. Sir John Pringle made a point of my applying for the money allotted for such purposes, which I did ; but there were reasons given for my not receiving it then. You have also desired me to apply, which I have done, both to Mr. Wegg and Mr. Robertson, but have been shifted from one to the other. I thought it my duty, both to yon and the Society, to acquaint you of this. I have the honour to be, with great respect, " Your most obedient and most humble Servant, John Hunter." 64 THE LIFE OF JOHN HUNTER. did not give any lecture. In these discourses he unfolded many novel and ingenious views respecting the causes of motion in vegetables and animals, and on the various modes of progression employed by the latter, in swimming, flying, leaping, running, &c. At their conclusion the Royal Society expressed a desire of publishing them; but Hunter objected to it, as he did not consider his information sufficiently complete for this, and was accordingly allowed to withdraw them, with a view to publication at some future period. He never found leisure, however, to carry this intention into effect; but some of his observations were introduced into the work on Inflammation, and others Sir Everard Home embodied in his own publications on comparative anatomy. The latter have met with general approbation amongst continental physiologists, but they have not always been traced up to their true author. He also presented this year a paper on the organ of hearing in fishes, in which he gives a general account of the structure of the organ in this class of animals, and shows that in the Ray tribe and some other fishes there is an external opening. He was the first who pointed out this fact, and, as appears by the following letter, was anxious to secure himself the credit of his discovery, which he feared some other philosopher might run off with; since, from the date of the following letter, it would seem that his paper had been given in the year before, but for want of opportunity could not be read. " Dear Sir Joseph, 1781. " If it was possible and agreeable to read a little bit of my paper upon the ears offish, so as to be able to publish it, I should be glad, as somebody now will rob me of the external opening in the Ray kind, and in other fish.* I have left it open for future inquiry, because I have a preparation of it, but cannot say what fish till I shall learn that by future inquiries; but all this I leave to you, as I know you have my credit at heart. " I am, dear Banks, your much obliged, John Hunter."

In 1783 Hunter was elected a Member both of the Royal Society of Medicine and the Royal Academy of Surgery in Paris. The lease of his house in Jermyn-street expiring this year, he purchased the remainder of the lease of some more extensive premises, now occupied by the National Repository of Arts, on the east'side of Leicester-square, consisting of a dwellino--ho\ise in the square, with a large portion of ground extending to Castlestreet, where there was a second smaller dwelling; between the two he determined on building a museum. That this was a very imprudent transaction, in a pecuniary point of view, there can be no doubt. His lease was only for twenty-four years, and the sum he expended in the building was not less than three thousand pounds. It seems, however, that his mind had been so harassed with the difficulty of obtaining an eligible site, that it was a relief to be able • Dr. Hunter used to say that "philosophers lie like the devil." It would seem that his brother thought they also thieved like the devil; and we must allow him to have had some experience. THE LIFE OF JOHN HUNTER. 65 to conclude even such a bargain as this. The new building was to consist of a room above, for the reception of his collection, fiftytwo feet long by twenty-eight wide, lighted from the top, and furnished with a gallery all around. Under this were two apartments, one of which he designed to employ as a lecture-room; the other, for which no particular use was at first allotted, afterwards became the place of meeting for the Lyceum Medicum, a society which Hunter and Fordyce were the means of establishing, and of which they were chosen two of the patrons. All that Hunter could spare from his income was for the next two or three years devoted to carrying the above plan into effect, and he used often to complain to his friends that he was now obliged to spend in bricks and mortar what would have been otherwise expended in enlarging his collection. To the new building, the house in Castle-street was subservient, and in the various apartments of it the different, departments of human and comparative anatomy were carried on. The house in Leicester-fields was occupied by Hunter and his family. Notwithstanding his architectural engagements, Hunter found time to take an active part, with Dr. Fordyce and others, in the formation of the " Society for the Improvement of Medical and Chirurgical Knowledge," which was established in 1783, and continued in existence about twenty years. This, like the present Medico-Chirurgical Society, had its appointed meetings for receiving and discussing treatises on medical subjects, and those which were judged worthy of it were reserved for publication. During the whole existence of the Society only three volumes of transactions were published; but these contain many valuable papers from the pens of Fordyce, Hunter, Baillie, Home, Blane, Wells, Abernethy, and others. Amongst the early contributors we also find the name of Jenner, whose attention had lately been turned to improving the mode of preparing the emetic tartar, and who communicated the results of his experiments in a paper to the Society. Several of Hunter's letters to Jenner, written about this time, relate to the subject, in which, as usual, he took a kind and active interest. "Dear Jenner, [Post-mark Nov. 14/A.] " I received yours, with the experiments on heat and colours, but have not had time to pay sufficient attention to the colours. I also received your little publication with the Tart. Emet. I have a great deal to say about it. First, do you mean to take out a patent ? Do you mean to advertise it? or do you mean to let it take its chance ? I approve of it much, and will do all in my power to promote the sale; but I would advise you to give it a new name, expressive either of the composition, or of its virtues on the body, viz. sal antim., or sal sudorif., or sal antim. sudorif. I would also desire you to burn your book, for you will have all the world making it. Let me have your answer to all this. "Ever yours, J. Hunter."

The piece of advice given in the latter part of the foregoing letter affords an example of that want of high professional feeling occasionally displayed by Hunter. Perfect liberality in the communication of professional knowledge which may contribute to the general benefit should ever characterize the enlightened physician. 66 THE LIFE OF JOHN HUNTER. It is this conduct which forms the honourable distinction between quackery and one of the noblest of human pursuits ; and the practitioner who, in seeking after wealth, neglects to observe it, deserves to rank only with the venders of secret medicines and professors of secret modes of cure, who in all ages have found ready dupes amongst the ignorant and credulous, whether of high or low degree.* Jenner had too high a respect for his professional character to follow the advice, and, accordingly, made his method generally known, by publishing it, as has been before observed, in the Transactions of the Society for the Improvement of Medical and Chirurgical Knowledge, a channel which, as will be seen in one of his future letters, Hunter himself recommended. The following letter was probably written soon after this proceeding, as it is filled with directions respecting experiments on colours, a subject on which, as we have there seen, Jenner had been making some experiments. The want of this gentleman's letters leaves us to guess at the object of the experiments proposed, but from their nature it may be inferred that they were to be conducted on an individual labouring under that incapacity for discriminating between certain colours which is not unfrequently found, ina greater or less degree, in different individuals. Hunter's object appears to be, to ascertain whether the incapacity arises from a general defect in the perceptive power, or whether certain primary colours fail to make their accustomed impression, and hence the compounds into which they enter appear different from what they really are.

" Dear Jenner, " I thank you for your last letter: I want you to pursue the inquiry considerably further: and to give you an idea of what I mean, I will first premise that there are in nature but three colours, viz. red, blue, and yellow, all the others being

* Notwithstanding some late notable instances of successful imposture, there seems fair ground for believing that quackery is on the decline in this country. We should hardly, in the present day, find a judge proclaiming from the bench his belief that a bone-setter was just as skilful and efficient in his business as any surgeon ; nor can Sir Benjamin Brodie complain, as Mr. Pott did, that any Mrs. Mabb drives her carriage and four into London to take charge of the dislocated limbs of the nobility and gentry. It would appear, from the following anecdote, that in Hunter's time these worthies were even admitted into consultation by well educated professional men; and we know that certain departments of surgery, as the operations on the eye, &c, were still entrusted to men ignorant of the first principles of medicine. The Taylors of Whitworth were empirics who enjoyed much repute in treating diseases of the rectum. Thurlow, bishop of Durham, and brother of the Lord Chancellor, laboured under stricture of the rectum, for which the faculty promised little relief. The Chancellor invited Taylor to see his brother, and several medical men met him in consultation: Hunter came late, and Taylor was invited to proceed in the examination ; but he bluntly refused, and said he would do nothing till Jack Hunter came, for he had no opinion of any but him. Hunter soon arrived : Taylor made his examination, and declared it a bad case; but passed a candle, besmeared with an ointment he had brought with him. Hunter took up the box, and asked what the ointment was made of. "That," said Taylor, turning to the Chancellor, "is not a fair question : no, no, Jack, I'll send you as much as you please, but I won't tell you what it's made of." THE LIFE OF JOHN HUNTER. 67 combinations of these three. First, present him with these three colours singly and see what he calls them; then altogether (not mixed), and see how far they correspond with his first ideas of thern : when that is ascertained, then beo-in to mix them; for instance, blue and yellow (which make a green), see what he calls that; then a yellow and red (which make a scarlet) ; next a blue and red (which make a purple). Now to explain the intention of these experiments. Suppose he has a perfect idea only of one colour; and although you mix that colour ever so much, yet he sees none of the other, but only that colour in the mixture. Suppose all the three colours, when seen singly, or unmixed, with him are blue; mix blue and red (making a purple), he will only see the blue, the red not being visible to him; and so on of the others, according as he sees them. Suppose that a simple colour makes no impression, but a compound one does, viz. green (which is composed of blue and yellow); then mix blue and red in all proportions, to see what the colour is. Then mix yellow and blue in all proportions, and see what colour these are: if he sees no green in any of them, then mix all the three colours in various proportions, and see what colours those make. When all the colours are mixed in various proportions, and the whole is a green, perhaps of different shades, according to the quantity of blue and yellow, then you may fairly conclude that it is the mixture of the blue and the yellow which produces it, the red never making any impression. "If there is any other simple compound that he sees, as scarlet, which is the yellow and the Modena red ; or a purple, which is blue and red ; see if, when those two are predominant in the mixture, (although there are all three colours in the mixture,) that the compound becomes the visible colour. "The drawing of the skull has been made ever since you desired it, but I had forgot it. I have a cast for you of the aneurismal varix, as described by Dr. Hunter. How shall I send both ? Let me know. " Ever your much obliged, John Hunter."

The following letter,* which was probably written about this time, relates to the metaphysical inquiry as to the nature of matter. It appears to have been nastily written, and certainly does not lead us to regret that Hunter did not more often quit natural philosophy for metaphysics. Both facts and reasoning are unsound.

" Dear Jenner, " I received yours, with the heron's legs. Could you not get a live heron or bittern,—or see how they make that noise,—and send them to me ? I will pay expenses. By the by, you were to have sent me some hedgehogs. I am putting my things into some order, and shall find some Don Saltero's for you. " My proof of the non-existence of matter is in colours, there being no such thing as a primary colour, every colour being a mixture of two, making a third. Thus, green is a mixture of blue and yellow; blue is a mixture of purple and green ; yellow is a mixture of green and orange; and so on of the other colours. Therefore all colours are compounds. But what are they compounds of ? Of nothing but themselves. And what are themselves ? Nothing. If there were three colours that were permanent, (for with less than three we can hardly compound to" any extent,) which could not be produced from any compounding of colours, then I would say, there is something immutable in matter, although metaphysicians might say this was only an immutable idea, or an idea of immutability ; but that is only applying abstract reasoning to matter, or what we call matter; but when we see that there is no such thing as permanency in one species of matter, viz. light, and that it can be proved from the matter itself, it then comes more home to our understandings than all the reasoning in the world. " Yours always, J. H."

His next letter, written in December, relates almost entirely to Jenner's new medicine. 68 THE LIFE OF JOHN HUNTER. " Dear Jenner, [Post-mark Dec. 15/A.] " I have delayed writing longer than I intended, and longer than what I should have done, and even now I do not know well what to write. I love a new name so well that I could have wished it had been christened. Mr. Jones intormed me that tliere was a man of some fortune making experiments with the same view; he may hit on some method better than the present, and which may or may not be as good as yours; or it may be thought to be as good. I asked Jones if he had any objection to have it advertised at his shop : he did not give me a direct answer, and he is now out of town. I should be glad to have a few of the printed accounts. I could send them to different people ; to Black and Cullen,&c., amongst the rest. I like your experiment upon the dogs with it: if you make any more, let me have them. The experiment on the dog's thigh you did not finish. You told me he had extracted the plug.and that the ball of the thermometer went in with ease, but you did not say how high the mercury rose. Let me know what service I can be to you. " J. Hunter.

Hunter's next communication appears to have been made early in the year following. He again recurs to the tartar emetic ; but other subjects are mentioned, especially the question as to the mode in which the young cuckoo is reared, a point which Jenner was at this time, at Hunter's request, endeavouring to clear up.

"Dear Jenner, " I am puffing off your tartar, as the tartar of all tartars, and have given it to several physicians to make trial, but have had no account yet of the success. Had you not better let a bookseller have it to sell, as Glass of Oxford did hia magnesia? Let it be called Jenner's Tartar Kmetic, or anybody's else that you please. If that mode will do, I will speak to some, viz., Newberry, &c. " You are very sly, although you think I cannot see it: you very modestly ask for a thermometer; I will send one, but take care those d—d clumsy fingers do not break it also. I should be glad to have a particular account of the cuckoo, and, as far as possible, under your own eye. To put all matters out of dispute, if the cuckoo's eggs were taken out of the hedge-sparrow's nest in which they were laid, and put into another's, by human hands, there could be no supposition that the parent cuckoo would feed or take care of them. I also want some young ones. I had a series from you, but a moth got in among them, and plucked them. Let me hear from you when you can. "Yours, J. Hunter."

Jenner had been also engaged in making some observations on the migration of swallows, the result of which he communicated to Hunter, who, in his reply, suggests a difficulty with regard to one of the observations.

" Dear Jenner, "To show you how much 1 am pleased to hear from you, I sit down to acknowledge the receipt of yours this evening. Somebody before told me, of your experiment on swallows; but you should not have made the same experiment on both the old and the young of the same nest, for you do not know whether it was the old or the young that returned. I have been for some time goina to write to you, to inform you there" is a medical society set up here,* who intend to give papers in medicine and surgery, and also to receive. 1 think your paper on the Tart. Emetic would make a good paper, and probably the one on the ophthalmia, which you may probably take a little more pains about. If you should like to have them published, I can communicate them. If your account of the cuckoo is not so full as you see it may be, keep it to another year, for I am in no hurry. " I am, dear Jenner, ever yours, » Jan. 26th. J0HN Hunter." * Society for the Promotion of Medical and Chirurgical Knowled THE LIFE OF JOHN HUNTER. 69 In February Hunter's paper on Inflammation of the Veins was read before the Medical Society above mentioned, and is included in the first volume of their Transactions. Hunter was the first who understood and explained the nature of this affection, which he has described in several of its more usual forms. Little attention seems to have been excited by it at the time. Mr. Abernethy indeed, not long after, contributed some additional information on the subject; but from that time until 1815, when Mr. Hodgson recalled the attention of the profession to the question, no pathologist had pursued the inquiry farther. Since that time much additional light has been thrown on the nature of these affections by the labours of Carmichael, Travers, Guthrie, Arnott, and Dr. Lee in this country, and MM. Bouillaud, Velpeau, Breschet, and Ribes in France, by whom it has been shown that many of the important and dangerous symptoms following venesection, amputations, parturition, &c, are due to inflammation of the internal coats of the veins. In May Hunter wrote again to Jenner, and requested him to draw out his process for making tartar emetic, that he might present it to the Society for the Promotion of Medical and Chirurgical Knowledge. "Dear Jenner, " You must excuse me if I am not very punctual in my answers : it is my loss, not yours. In my last but one you mention my having anything of the porpoise I wanted. I should be glad of one of the nipples. I hope you have got the thermometer. I want the cuckoo cleared up : I am afraid it is now too late. I wish you would shoot an old one for me, and send its gizzard in spirits. " I wish you would draw out the process for making the tartar emetic. The physicians that I have given it to speak well of it as a more certain medicine than the other; however, I am afraid it will be too late for this year's publication ; but put it to paper. Your paper must be published before you can think of being a member, and then we will stir for you, Ever yburs, " May 29th, John Hunter."

Jenner immediately complied with his directions, and his paper was read at the first meeting of the Society, in June. In the course of this year Mr. Home returned to London on leave of absence from Jamaica, where he had been acting as Staff- Surgeon, and on his arrival was permitted to exchange on half pay. " I found Mr. Hunter," says he, " advanced to a very considerable share of practice, and a still greater share of public confidence :" and he afterwards adds, " at this period Hunter may be considered as at the height of his chirurgical career ; his mind and body were both in their full vigour; his hands wrere capable of performing whatever was suggested by his mind; and his judgment was matured by former experience;" in confirmation of which he goes on to mention some of the remarkable operations which Hun* ter- successfully performed about this time. With regard to this latter point, namely, Hunter's talents as an operator, a remarkable diversity of opinion exists amongst competent judges. By some, Sir Everard Home's account of his great 8* 70 THE LIFE OF JOHN HUNTER. skill is most fully confirmed, whilst by others his ability in ihis department of surgery is rated very low. In the opinion of Sir Astley Cooper, whose judgment on the subject must be considered as at least as likely to be correct as that of any man living, Hunter scarcely deserved to be considered a dexterous operator, certainly not an elegant one: but his large experience, and his extraordinary skill as an anatomist almost always enabled him successfully to complete any operation he undertook: though slow, he was sure. Hunter does*not seem, indeed, to have been ever ambitious of particular renown in this field. He used frequently to say, " To perform an operation, is to mutilate a patient we cannot cure; it should therefore be considered as an acknowledgment of the imperfection of our art." The new building which Hunter had been erecting for his museum was completed in 1785, and Mr. Home, Mr. Bell, and Mr. Andre, whose services Hunter had engaged, were employed in superintending the removal of the preparations to their new site. If Hunter's building-expenses had of late prevented his purchasing objects for his collection, he appears now to have again begun to add to its stores. We accordingly find him making his accustomed calls on Jenner for objects of natural history, and, amongst others, for a bustard, the largest and one of the rarest of English birds.

" Dear Jenner, "I am very much obliged to you for your attention to me. I will very readily give three guineas for the bustard, therefore give such orders as you think fit. I request the whole history of the cuckoos this summer from you. I have bought a house in Leicester-fields, and shall move this summer, when I shall be able to pick out some things for you. Give my compliments to Clench, and I hope to see him before he sets out for Newfoundland ; if I do not, let him think of the white hares, to tame a buck and doe, and send them to me. Let me know in your next what you are doing. I hope to see you in London in about two years hence, when I shall be able to show you something. " I am, dear .Tenner, ever yours, John Hunter. " When the bustard arrives, I will write to you."

The bustard was accordingly procured and sent, and the receipt of it acknowledged in the following letter.

" Dear Jenner, " I have received the bustard safe, as also the bones. Your friend Mr. Hazeland has been very kind, for which I wrote to him and thanked him ; but when you see him or write to him, express the same, as an indirect thank is better than a thousand direct ones. Are hedgehogs in great plenty ? 1 should like to have a few. You must pursue the cuckoo this summer. 1 am employed building, moving, &c. I wish this summer was well over. When I am fitted up, I hope you will come and see me. Ever yours, "April22. J.'Hunter."

Soon after the date of the foregoing letter, Hunter beo-an to suffer from a very painful and distressing affection of the heart and arteries ; an affection, to the recurrence of which he was constantlv liable during the remaining years of his life. He had been troubled, as usual, during the early part of the spring, with slight symptoms THE LIFE OF JOHN HUNTER. 71 of gout; after a time these subsided, but were succeeded by irregular spasmodic affections of the face, arms, chest, and stomach, and finally, by a violent spasm of the heart, which, after half an hour of agonizing pain, ended in syncope. The faintness continued about ten minutes, at the expiration of which he started up, without any recollection of his previous illness. Similar attacks, though slighter in degree, returned very frequently for some time after, especially on occasion of any extra exertion or mental anxiety; and indeed the latter cause seems to have been mainly instrumental in exciting the first incursion of the disease, for when pressed by Dr. D. Pitcairn on this point, he admitted that his mind had been much harassed with a fear lest he should be attacked by hydrophobia, in consequence of a wound which he had received in the hand whilst examining the body of a person who had died of that disease. After a time the spasms became less frequent, though even now they were easily re-produced by a fit of anger, or by trifling anxiety of mind, as about the hiving of a swarm of bees, the fear lest an animal, which he wished to procure, might escape before a gun could be brought to shoot it, and similar causes. Various remedies were of course tried for the relief of his sufferings, but with scarcely any effect; and, amongst other means, he was advised to try the waters at Tunbridge. Thither he accordingly went in August; but after a fortnight's trial, finding himself rather worse, he resolved on repairing to Bath, where he had formerly derived much benefit. He arrived at Bath early in September, and in the following letter we find Mrs. Hunter communicating to Jenner the presence of his friend in his neighbourhood. " Dear Sir, Bath, Sept. 13, 1785. " I take it for granted you will not be sorry to hear Mr. Hunter is so near you, though you will lament that want of health is the occasion. He has been tormented with a flying gout since last March, and we are come here in hope of some favourable crisis before the winter. He has been inquiring for the post to Berkeley, and I find within this hour that it goes off this evening: as he is now asleep after dinner, I rather write myself than disturb his nap, to inform you of our being in your neighbourhood, and that Mr. Hunter will be glad to hear from you. I am, dear Sir, your obedient Servant, "No. 12, South Parade. A. Hunter." Hunter remained in Bath about five or six weeks, and derived some little amelioration of his sufferings. At the end of that time he returned to London, and resumed his occupations. During the whole of this illness, and of his absence from home, his brother-in-law, Mr. Home, was intrusted with the care of his practice. This gentleman therefore necessarily became an inmate of his house, and as Hunter's state of health, even after his sojourn at Bath, was too infirm to allow him to dispense with the presence of an able assistant during the performance of important operations, and to attend to night calls, Mr. Home continued to act in this capacity up to the time of Hunter's death. Hunter's continued ill health had prevented his contributing as 72 THE LIFE OF JOHN HUNTER. largely as usual to the Transactions of the Royal Society. The only communication which he made this year was an appendix to a paper of Mr. Home's on the Double-coned Terebella, an animal which he had brought with him from the West Indies. The infirmity of his body had not, however, abated his ardour for the improvement of his profession, and it was in December of the present year thai he planned, and carried into execution, his famous operation for the cure of aneurism ; that of tying the artery at a distance from the tumour, and between it and the heart, instead of laying open and emptying the sac, and then seeking for the orifices of the vessel, according to the old operation. He was led to propose this improved method in consequence of the frequent failure of the operation by the old mode, and thus introduced into surgery an improvement which has been more fruitful in important results than any since Pare's invention of the ligature for divided arteries. Our Gallic brethren have stroven hard to dispossess Hunter of the honour of this invention, and have adjudged the whole merit to their own countrymen. This of course. Three candidates, Guillemeau, Anel, and Default, have accordingly been brought forward, to each of whom they have decreed a certain portion of the honour, and whose united services, as they assert, entirely forestalled those which it has been generally thought that Hunter rendered to surgery by his successful operations. The following are the grounds on which these pretensions rest. Guillemeau, a pupil of Pare, in a case of aneurism of the brachial artery, caused by a puncture in bleeding, tied the vessel immediately above the tumour, then opened and emptied the sac, and healed it from the bottom. Anel, about a century after, in a similar case, tied the artery as Guillemeau had done, but left the sac unopened. Desault, a few months before Hunter's operation, placed a ligature on the artery in the ham, above the tumour, in a case of popliteal aneurism: the sac inflamed, suppurated, and discharged its contents; a fistulous sore remained, and the man died at the end of seven or eight months. Now, of these three operations, that of Guillemeau appears to be absolutely devoid of any shadow of claim to be considered as even a first step towards Hunter's. It was simply the old operation reversed ; instead of first opening the sac and then tying the artery, he lied the artery first, and opened the sac afterwards. Anef's operation undoubtedly merits more consideration, and it must be admitted that he first demonstrated the truth of one of the important principles on which Hunter's operation is founded, namely, that theimpulse of the blood into the aneurism being restrained by a ligature placed on the artery above the tumour, the further progress of the dis' ease will be checked, without the necessity for a ligature being also placed on the artery below the tumour. Two other principles however remained to be proved. First, That the powers of absorih tion would suffice for the removal of the coagula in the sac, and the necessity for opening it be thus done away with. Second That THE LIFE OF JOHN HUNTER. 73

the anastomosing vessels of the limb, in their natural state, would be capable of immediately taking on such increased action as icould suffice for carrying on the circulation to the parts below the point at which the main artery was tied. With respect to the first of these two principles, Anel's operation proved nothing, for he succeeded, or thought he succeeded, in first emptying the tumour of its contents by pressure, before tying the arterv. Neither did Desault's operation prove this point, for we have'seen that the sac burst, and discharged its contents. It is true that the removal of the tumour, in the cases of natural cure of large aneurisms, related by Valsalva, Guattani, and others, must have depended on this power in the absorbents, but these authors were not aware of this, and attributed their dispersion to the effect •of pressure, resolvents, &c. Nor was the possibility of the coagula being so removed generally admitted by later authors, until after Hunter's operation. Although it would appear, therefore, that Desault intended to trust to the action of the absorbents when he tied the arterv in the ham, without opening the sac, yet it was Hunter's operation that reallv proved the sufficiency of this action. With regard to the third principle, I think a candid examination of the question will satisfy any one, that previously to Hunter's operation it was universally disbelieved that the anastomosing vessels, when not previouslv enlarged, would be equal to carrying on the circulation of a limb, after a ligature of the main artery._ It was by acting in opposition to this general disbelief, and proving their sufficiency for this office, that his operation became the fruitful source of the numerous improvements in the treatment of lesions of the arteries which have since been introduced into surgery. No doubt, both Anel's and Desault's operations required, for their success, that the circulation should be carried on by the anastomosing vessels, just as the old operation did ; but that it was so carried on was accounted for by supposing that the anastomosing vessels in the neighbourhood of the tumour had undergone a gradual dilatation, in consequence of the pressure of this on the main artery. No one had hitherto generalized on the fact, and to place a ligature on the artery in the middle of the thigh, where no such dilatation of the anastomosing vessels had taken place, would have been, in the general opinion, to ensure mortification of the parts below. So deeply rooted was this opinion in men's minds, that some years after Hunter's first operation, we find Pott, in a case of popliteal aneurism, recurring to Desault's operation in the ham, rather than risk mortification by placing the ligature as Hunter had done; and his pupil, Sir James Earle, following his example as late as 1792: and even long after this, many of the French surgeons continued to employ various preliminary measures to cause a dilatation of the branches previously to operating, until repeated successes, without these precautions, had shown their uselessness. If, as it is pretended by French surgeons, Anel's operation was the prototype of Hunter's, how are we 74 THE LIFE OF JOHN HUNTER. to account for the fact, that during the three quarters of a century which intervened between them the former was never once imitated, whilst the latter was not only immediately imitated, but speedily led to other most important improvements in the operations on arteries ! The truth is, neither Anel, nor any other surgeon before Hunter, conceived that it was possible to make those important modifications in the operation which the latter introduced, and which could alone render it generally applicable: modifications so important, as in fact to render it a new operation based on new principles. A convincing proof of this is afforded in the very operation of Desault which has been adduced to deprive Hunter of part of the honour which is his due. Had Desault believed in the feasibility of tying the artery in the thigh, would he, in reviving Anel's operation, have followed it so closely as to seek the artery in the ham, where the operation is more difficult, not only from the greater depth at which the vessel is placed, but from the consolidation of parts by previous inflammation? Assuredly not. Another important advantage, too, which Hunter's operation possesses over that of Desault, is the greater chance it affords of finding the artery in a sound state, a consideration so important as to have formed the principal inducement with Hunter to propose his operation. The difference, then, between the operations of Hunter and Desault, was not, as M. Velpeau pretends, merely that of the ligature being placed two or three inches higher in the one case than in the other; they were essentially different in principle, and justice demands that we should vindicate the claim of Hunter to the entire credit of inventing an operation the importance of which was speedily estimated as it deserved, and which has led to those valuable improvements in the treatment of the lesions of arteries of which modern surgery is justly proud. It will be seen in the account of the operation given by Sir Everard Home, that Hunter committed some errors, in the first two cases, in the mode of applying the ligatures, which he afterwards corrected. He separated the artery from its connexions to a much greater extent than was safe, and this in order that he might apply four ligatures, which were intended to afford increased security ; but so far from producing this effect, did in reality greatly augment the dangers of the operation. These points, however, belong rather to the history of surgery than to a memoir like the present, and as the observations on the subject have already extended to an almost undue length, I must hasten to resume the thread of this narrative. In 1786, in consequence of the death of Mr. Middleton, Hunter was appointed Deputy-Surgeon-General to the armv. In the earlv part of the same year he published his work on the" Venereal Disease, which had been long expected by the public, and which met with a rapid sale. On this work Hunter had bestowed great pains, and before publication he submitted every part of it to a committee THE LIFE OF JOHN HUNTER. 75 of his friends, consisting of Sir Gilbert Blane, Dr. Fordyce, Dr. David Pitcairn, and Dr. Marshall. It is said that the amendments introduced by these gentlemen were numerous; some have wished that they had been still more so, at least as regards the purely theoretical parts of the treatise. A great diversity of sentiment has prevailed as to the specific or non-specific nature of the disease. The former was decidedly the most prevalent theory at the time Hunter wrote, and he adopted it in all its latitude, and endeavoured to point out the peculiar laws by which it was regulated. Of late years the latter opinion has been gaining ground, and few would now be disposed to go the length which Hunter did when he proposed as a test whether certain diseases be or be not syphilitic, their requiring or not requiring mercury for their cure. Whatever may be thought, however, of Hunter's theory, it cannot be denied that his work contains many ingenious and striking views, and a variety of valuable observations on the various stages and forms of the disease: hence, notwithstanding some improvements which have been since introduced into the treatment of these affections, Hunter's still remains by far the best general work, and requires only the corrections of the gentleman who has undertaken this part of the subject, whose experience of these affections have been of the most extended kind, to render it the universal book of reference on this complicated and Protean disease. Towards the end of this year he published also his work on the Animal G3conomy,* consisting chiefly of a collection of his most important papers in the Philosophical Transactions, to some of which he has made considerable additions. Besides these, the work contains his paper on the descent of the testis in the foetus, with large additions ; his account of the structure of the placenta, which the Royal Society had declined to publish; and other shorter memoirs, of minor importance. This volume is undoubtedly one of Hunter's ablest productions, consisting as it does of accurate anatomical descriptions of various parts of the animal structure, together with original and ably conducted researches and sound and striking conclusions on some of the most important questions in general physiology. It has been before remarked, that we can seldom form an adequate notion of the contents of Hunter's various papers from the titles which he gave them. This remark is fully exemplified in those contained in the Animal CEconomy, a know-

* Hunter adopted the plan of printing the first edition of this work, as he did several of his previous works, under his own eye, and indeed in his own house. His reason for doing this was, that before the Irish Union it was no unfrequent proceeding with booksellers to send a copy of the manuscript, or else the proof sheets, of any valuable work to Dublin, where a cheap edition was hastily got up and imported to England so as to be ready for sale as soon as the original work, by which means the author was deprived of the profits which would have accrued to him from a second edition being called for. This proceeding, however, gave great offence to the booksellers; and as some of them were old friends, with whom he did not wish to quarrel, he gave the publication of the second edition to Mr. Nicol, of Pall Mall, and Johnson, of St. Paul's Church-yard. 76 THE LIFE OF JOHN HUNTER. ledge of which is necessary to such as desire to become well acquainted with the Hunterian museum, or with the style and strength of his reasoning on physiological subjects. We may also easily discern, in some of his remarks, the germs of important doctrines in physiology which have been since enlarged on and given to the world as new discoveries. The correspondence between Hunter and his friend Jenner had gradually become more infrequent; not from any decrease of .their mutual esteem, but from the increasing occupations of both. The following letters, however, appear to have been written during the latter part of this year, and refer to a subject which had been frequently mentioned before, namely, Jenner's researches respecting the cuckoo.

" Dear Jenner, " I have been long expecting a long letter from yon, informing me of your method of curing ophthalmias, history of cuckoos, &c. I received your dog-fish ; are you sure that the spawn or egg came from her? there were none in her: if it did, then there is a species of dog-fish oviparous. Let me hear from you soon. "Sept.1th. Ever yours, J. Hunter."

" Dear Jenner, "I have all your letters before me, but whether I have answered a«iy of them or not I cannot recollect. First, I thank you for your account of the cuckoo, and what further observations you can make I shall be glad to have them, or even a repetition of the former will be very acceptable. I received the bird: it is well known; but I look upon myself as equally obliged to you. I also received your cocks, which were very good. I have bought the print of Wright, viz. the Smiths, which is his best. There is one more 1 would have you have, I mean Sir Joshua Reynolds's print of Count Ugolino : it is most admirable, and fit only for a man of taste. We had a sale of bad pictures lately, but there were some good heads : I gave a commission for them for you, thinking they would come cheap, but unluckily there were some that saw their merit as well as I, and they sold above my commission. Pictures seem to be rising again. I will not send you yours till I hear from you. "I am told there is the skin of a toad in Berkeley Castle that is of prodigious size. Let me know the truth of it, its dimensions, what bones are still in it, and if it can be stolen by some invisible being. I buried two toads last August was a twelvemonth ; I opened the grave last October, and they were well and lively. " Have you any queer fish? Write to me soon, and let me have all the news, &c. &c. " Anny sends, with little John, their compliments. From yours, &c. John Hunter."

Jenner having at length completed, as he supposed, his observations on the cuckoo, drew them up in the form of a paper, to be read before the Royal Society, and transmitted it for this purpose to Hunter, who in the following letter, states the reasons why he had not already presented it.

" Dear Jenner, [Post-mark April 26.1 " I received your papers, and should have presented them to the Royal Society before now, but for almost the whole, of this winter we have had nothing but disputes in the Society, and giving up of Secretaryships, &c, and are not yet settled ; but when we are I will give in your paper, but shall take a copy of it, that in case they should not publish it in the Transactions, it may be probably published by the Medical Society, who will make it of more use than the Trans- THE LIFE OF JOHN HUNTER. 77 actions. The person you mentioned, who was attempting to make the medicine, called on me and left his name. When you have anything new, let me hear from you. " I pity poor Cheston, for the loss of his son. Ever yours, " John Hunter." Shortly after this Jenner's memoir was read, and would have been published in the Transactions for 1787, but since delivering il he had discovered the fact that the eggs and young of the hedgesparrow are ejected from the nest by the young cuckoo, and ribt by the parent bird, as he had at first supposed; he was therefore allowed to withdraw the paper, in order to correct this error, and its publication was put off till the year following. Whilst Jenner was pursuing his observations on the cuckoo, Hunter, it would seem, was busied in trying to make pearls, by introducing extraneous substances into oysters, as nuclei, for them to form on. What success he met with does not appear, and indeed the following letter of his to his friend Sir J. Banks gives us all the information we possess respecting this inquiry. "Dear Sir Joseph, 1787. " I have these two days been draining the pond, or rather fishing for pearls, the success of which you will see by the specimens. Those I had made the experiments on were dead, but there is one recent. I have a few alive that I mean to put under experiment; but I shall open the shell and put in the extraneous body. If any other method suggests itself to you, be so good as to inform me. I would not have you make Lady Banks a present of them; I hope to get better, at least as large as my thumb. I lately got a tall man, but at the time could make no particular observations. I hope next summer to be able to show you him. " I am, dear Sir Joseph, " Your much obliged, John Hunter."

Hunter presented two papers to the Royal Society in the course of this year. 'The first contains observations tending to show that the Wolf, Jackal, and Dog are of the same species. The second is a long and valuable treatise on the structure and economy of Whales, illustrated by a number of very excellent engravings. Hunter had pursued his researches on these animals with great diligence and success, considering his necessarily limited opportunities for making observations. In this paper he mentions a fact which shows how little he spared expense in the pursuit of his favourite studies. As he found it impossible to obtain proper subjects on which to pursue his inquiries to the extent he desired, he engaged a surgeon, at his own expense, to proceed to the North in a Greenland whaler, after having given him such anatomical instruction, and provided him with such other means as would, he supposed, enable him to obtain some valuable information respecting the Whale tribe. But his choice of a messenger proved an unfortunate one: for all that he got, in return for his trouble and expense, was a bit of whale's skin, with some barnacles stuck on it. This eagerness of his to obtain rare and valuable specimens for his museum, often led him to pay more than its worth for an object he desired to make his own, as the following account of the manner 9 78 THE LIFE OF JOHN HUNTER. in which he acquired the skeleton of Byrne, which heads the osteological collection, will probably be thought to prove. Byrne, or O'Brien, the famous Irish giant, died in 1783. He had been in a declining state of health for some time previously, and Hunter, anxious to procure his skeleton, sent his man Howison to keep watch on his movements, that he might be sure of securing his body at his death. Byrne learned this, and as he had a horror of being dissected, determined to take such precautions as should ensure his not falling info the hands of the doctors: he accordingly left strict orders that his body should be watched day and night, until a leaden coffin could be made, in which it was to be inclosed, and carried out to sea and sunk. Byrne died soon a|ter, and, in compliance with his directions, the undertaker engaged fsome men to watch the body alternately. Howison soon learned this, found out the house where these men went to drink when off duty, and gave information to Hunter, who forthwith proceeded thither with the view of bribing them, to allow the body to be carried off He had an interview with one of the party at the ale-house, and began by offering him fifty pounds if he would allow the body to be kidnapped; the man agreed, provided his companions would consent, and went out to consult them. He returned shortly, saying that they must have a hundred pounds. Hunter consented to this, and thought the affair settled; but the men finding him so eager, soon came back with an increased demand, which was also agreed to; when further difficulties were found, and larger and larger, demands made, until, it is said, they raised the price to five hundred pounds ! The money was borrowed from Pidcock to pay them ; and in the dead of night the body was removed in a hackney coach, and after having been carried through several streets, was transferred to Hunter's own carriage, and conveyed immediately to Earl's Court. Fearing lest a discovery should take place, Hunter did not choose to risk the delay which the ordinary mode of preparing a skeleton would require ; accordingly, the body was cut to pieces, and the flesh separated by boiling; he»ce has arisen the brown colour of the bones, which in all other respects form a magnificent skeleton. The Royal Society this year conferred on Hunter the Copley medal, as an honourable testimony to the importance of his discoveries in natural history. He also received, about the same time, another mark of the estimation in which his labours were held, by being elected a member of the American Philosophical Society. The arrangement of Hunter's museum was now completed, and he had the gratification of opening it for the inspection of his friends and acquaintance during two months in each year; in October to the medical profession, and in May to those noblemen and o-entlemen who felt an interest in such subjects. Hunter's private practice was now so extensive, whilst his bodily health had so much diminished, that he determined on applying THE LIFE OF JOHN HUNTER. 79 to the Governors of St. George's Hospital to allow him an assistant. His colleague, Mr. Gunning, determined on making a similar application at the same time; and we accordingly find amongst the minutes of the Committee for this year the following entry : " Mr. Gunning and Mr. Hunter present their compliments to the gentlemen of the weekly board, and beg the favour of them to summon a Special General Court for the purpose of electing two assistants, a favour which has been formerly shown to Mr. Middleton, Mr. Hawkins, and Mr. Bromfield, in consideration of their many years' services to the hospital. " The persons whom they beg leave to recommend to this situation are Mr. Keate, Surgeon in ordinary to His Royal Highness the Prince of Wales, and Mr. Home, who has been bred up under Mr. Hunter. " They flatter themselves the propriety of their recommendation will render this indulgence the less exceptionable." The request was complied with, and these gentlemen elected, the Court suspending a by-law which forbade physicians or surgeons of the hospital to recommend assistants or deputies. Mr. Gunning and Mr. Hunter at the same time declared that it was far from their intention to give up the necessary attendance at the hospital. Hunter's friends had long been desirous to engage him to sit to Sir J. Reynolds for his picture ; but he had always hitherto declined to do so, not choosing that it should be done at the expense of others, and thinking the price too high for himself to pay. He was, however, at length induced to comply, chiefly to oblige Sharp, the eminent engraver, who had received much notice from Hunter, and was very anxious to be permitted to make an engraving from Sir Joshua's picture. Reynolds found Hunter a bad sitter, and had not been able to satisfy himself with the likeness, when one day, after the picture was far advanced, Hunter fell into a train of thought, in the attitude in which he is represented in the present portrait: Reynolds, without saying a word, turned the canvas upside down, made a fresh sketch, with the head between the legs of the former figure, and so proceeded to lay on over the former painting the colours of that which now graces the walls of the library at the College of Surgeons. From this portrait Sharp executed his engraving, which is admitted by the best judges to be one of the finest, if not the very finest specimen of the art ever executed. The doubt rests chiefly between this and another engraving by the same artist,* " The consultation of the Doctors on

* Poor Sharp, though a man of extraordinary talent in his art, was singularly devoid of common sense. He was a devotee, and a firm believer in the pretensions of the prophet Brothers and the aged virgin Johanna Southcote; but at the same time a man of profligate habits. Hunter was a great admirer of his talents as an artist, and possessed a large portfolio of splendid engravings by Sharp and other eminent masters in the art. Sharp always considered his engraving of Hunter as one of his happiest efforts, and was found poring over it with admiration forty years after he had executed it. Hunter took fifty copies of the engraving, at two guineas each, and the plate proved a milch-cow to the artist. One of the 80 THE LIFE OF JOHN HUNTER. the immaculateness of the Virgin," after Guido, for both are thought to be superior to the best efforts even of Raffael-Morghen or Desnoyers. Hunter's increased professional engagements prevented his continuing to be any longer so large a contributor as formerly to the Transactions of the Royal Society. During the next five years we find but one short paper of his, namely, a Supplement, in 1789, to his Observations on the Wolf, Jackal, and Dog, given two years before. Nor do we find that he contributed anything this year to the Transactions of the Medical Society before mentioned ; and for the future he generally entrusted to his brother-in-law the business of communicating an account of such improvements, or observations of a professional kind, as he thought deserved to be recorded. We find also that his correspondence with Jenner for this year was confined to a single letter, and that principally in reply to a consultation respecting a case of disease of the urinary organs, which Jenner had under his care.

"Dear Jenner, May, 1788. "I have been going to write to you some time past, but business and a very severe indisposition for three weeks past has prevented me ; but when two guineas rouse me, I cannot resist. Have you tried a bougie, to find if there is any mechanical stoppage ? As there is blood in the urine, is there no stone ? Would it not be right to try both ? But suppose no stoppage nor no stone, then I would push the cicuta: at the same time he should be very temperate in eating, drinking, and exercise; eat no salt nor made dishes ; drink no fermented liquors ; but plentifully of everything else, and be very quiet. " Your paper has been read, passed the Council, and is in print, for I had a proof sheet this day, and I have ordered fifty copies, twenty-five for you and twenty-five for myself, to give to friends. I spoke to both Sir Joseph Banks and Dr. Blagden about your wish. Sir Joseph has not the least objection, and will give us all his assistance, but he thinks the paper had better be first printed and delivered, and let the people rest a little upon it, for he says there are many who can hardly believe it wholly. This will put off the certificate till the beginning of next winter, when we shall hang you up. I have received a box, with a wapping landlady and two lizards. Mrs. Hunter's and my compliments to Mrs. Jenner. " I am, dear Sir, " Your most obedient Servant, John Hunter."

In December of the present year an event occurred which left to Hunter the undisputed title of the first surgeon in England; this

means by which Sharp succeeded in attaining to such perfection in his works was the following: he always kept a number of engravings in hand at the same time, in various stages of their progress ; it was his practice to commence working on those parts which required least delicacy in the execution, and when he had got his hand well in, or when he felt particularly in cue, immediately to transfer his operations to those plates which were in a state to require delicate manipulation. For the engraving of Hunter, which was prefixed to the first edition of his work on Inflammation, edited by Home, Sharp received fifty guineas, a large sum at that time. It is so exact a copy of the portion of the large engraving which it represents, that it was supposed by some to have been actually abortion cut out of the original plate ; there is, however, every reason to believe that this latter is still in existence. THE LIFE OF JOHN HUNTER. 81 was the death of the veteran Pott. It is true that for some years past Hunter had been in possession of a larger share of practice and of public confidence than any other member of the profession; but as Pott still lived, and, notwithstanding his advanced age, continued actively engaged in practice, the recollection of his former fame maintained to him a high degree of public esteem, and left it doubtftl to which of these eminent men the priority of station should be adjudged. On the 22d of December, however, this able surgeon and excellent man expired, at the age of seventy-five, after an illness of only a few days, having retained the full use of his faculties almost to his last moment. It will be recollected that Pott was amongst the earliest of Hunter's instructors in surgery, but in after-life they gradually assumed somewhat of a hostile attitude towards each other. A great dissimilarity existed in their characters and attainments ; and as, from the position which each occupied, and from other circumstances, comparisons were often instituted between them, it may not be uninteresting to endeavour briefly to show in what this dissimilarity chiefly consisted. Pott was a man of quick natural talents and of sound sense, which had been improved and strengthened by a good classical education, and by constant assiduous attention on his own part in after-life. As a surgeon he was thoroughly versed in the history of medicine in all ages, and knew well how to bring this knowledge to bear on the practice of his profession. His correct observation enabled him to discover many of the errors of his predecessors, and his ingenuity and judgment, to correct them; and thus by the combined'effeets of his own and others' experience, he was the means of introducing many valuable improvements into the practical departments of surgery. He was not fond of employing physiological reasoning to guide his practice, but aimed rather at founding his treatment on immediate analogy and induction from established facts than on broader general principles; the theoretical part of our profession, therefore, he did little to improve. As an operator Pott was eminently skilled; as a lecturer, clear, energetic, and fluent; as a writer, classically correct and elegant. In society he was agreeable, witty, and abounding in anecdote, and at the same time kind and gentlemanly in his manners. Though hospitable in his mode of living, he was prudent in regard to pecuniary matters, and though he commenced his profession poor, brought up a large family liberally, and left them well provided for at his death. t The account already given of Hunter has sufficiently shown how destitute he was of many of those acquirements which added lustre to the character of Pott, and which mainly contributed to obtain for him the high esteem which he so long and deservedly enjoyed. But in spite of these deficiencies, Hunter, by the force of hi's own genius, which was unquestionably of a much higher order than that of Pott, and by his unwearied industry, forced his way at length to the summit of his profession; and, as Dr. Beddoes observed, 9* 82 THE LIFE OF JOHN HUNTER. " when one heard that Hunter was at length the first surgeon in London, one felt a satisfaction like that which attends the distribution of poetical justice at the close of a well told tale." CHAPTER VI.

Mr. Hunter's high station in the profession at this period ;—anecdote of his early rising.—Mr. Thomas.—Sir A. Carlisle.—Mr. Lynn.—Instance of Mr. Hunter's generosity ;—stands godfather to Dr. Jenner's first child ;—his paper on intussusception ;—his paper on paralysis of the oesophagus.—Mr. Home's paper on the formation of loose cartilages.—White's New South Wales.—Mr. Hunter's illness ;—his violence of temper ;—his style of living ;—his fondness for bees ; —his Tory politics__Funeral of Sir Joshua Reynolds. Mr. Hunter's paper on bees ;—his letter to Sir Joseph Banks on this subject;—his surgical lectures ; —his work on the Blood and Inflammation.—Veterinary College established.— Mr. Hunter's disagreement with his colleagues at St. George's Hospital;—his death, and character as a private man and as a philosopher;—his will and effects; —the purchase of his museum.—Correspondence between Lord Auckland and Sir Joseph Banks on this subject.—The terms on which this purchase was finally made.—Rebuilding of the College of Surgeons.

We have thus traced Hunter's career from the time when, as a raw and uneducated youth, he first made his appearance on the stage of his future labours and his future fame, upwards through

" What rugged places lie between Adventurous virtue's early toils And her triumphal throne,"

to the period when, after forty years of almost unexampled industry, he had raised himself to the highest place, not only in the estimation of the public, but in the more valuable, because more discriminating, judgment of the most intelligent amongst the rising generation of professional men. By the latter he was looked up to as [the author of a new asra in surgery; and his opinions were current, not only amongst those who had been his immediate pupils, but amongst all the younger members of the profession who aspired to keep themselves on a level with the advancing state of medical knowledge. Hunter's behaviour was well adapted also to secure him the regard and the homage of his junior brethren ; for he was by no means backward in encouraging the advances of young men of talent who desired to cultivate his acquaintance, readily afforded any slight attentions in his power to those coming to London to finish their studies, and recommended such as had completed their education to situations in the army if he found them industrious and intelligent. It may be worth while to mention a few instances THE LIFE OF JOHN HUNTER. 83 of this sort, which, though trifling perhaps in themselves, will not be without value if they tend to illustrate the character of this eminent man. On his arrival in London, Mr. Thomas, in company with Mr. Nicol, by whom he was to be introduced, called on Hunter: they found him dressing. " Well, young gentleman," said Hunter, when the first ceremonies of introduction were over, " so you are come to town to be a surgeon ; and how long do you intend to stay 1" " One year," was the reply. " Then," said he, " I'll tell you what, that won't do; I've been here a great many years, and have worked hard too,* and yet I don't know the principles of the art." After some further conversation, Mr. T. was directed to call again in an hour, which he did, and accompanied Hunter to the hospital, where he said to him, after the business was over, " Come to me to-morrow morning, young gentleman, and I will put you further in the way of things; come early in the morning, as soon after four as you can." "it was summer: Mr. Thomas kept the appointment, and found Hunter, at that early hour, busily engaged in dissecting beetles. Mr. Thomas afterwards became his dresser at the hospital, and was finally recommended by him as surgeon to Lord Macartney's embassy to China, on returning from which he found that Hunter had died during his absence from England. Sir A. Carlisle, whilst a pupil at the Westminster Hospital, was anxious to become personally acquainted with Hunter. He introduced himself by calling and requesting his acceptance of a very delicate and well-executed preparation of the internal ear. Hunter was highly delighted with it, detained him to breakfast, and in the course of conversation encouraged him by saying, " Any man who will set about a business, and do it as you have done that ear, may do anything he pleases in London." On finding that Mr. C. had not yet attended his lectures, as a reason for which he assigned his not being sufficiently advanced in professional knowledge to profit by them, " That, Sir," said Hunter, " is very complimentary, but I will give you a perpetual ticket, and shall be glad to see you whenever you will call." This invitation was not neglected, and Mr. Carlisle's anatomical skill soon made him a favourite with Hunter, to whose collection he contributed several valuable preparations. Nor did Hunter confine himself to such minor attentions as these, but occasionally assisted young men whom he saw struggling with

* It is a not uncommon practice with great men to conceal the amount of labour bestowed by them on their works, in order to heighten the opinion of their genius. Hunter seems to have been above this artifice; he worked hard, and he cared not who knew it. His contemporaries might under-value his labours, because they could not understand their object, but he never doubted their usefulness. "Ah, John Hunter, what still hard at work!" said Dr. Garthshore, on finding his friend in the latter years of his life busy in his dissecting-room. "Yes, Doctor," said Hunter, "still hard at work; artd you'll find it difficult to meet with another John Hunter when I am gone." S4 THE LIFE OF JOHN HUNTER. pecuniary difficulties at the outset of their career, by sending them valuable patients; or even extended his kind consideration still further, as the following anecdote, which is not quite correctly related by Mr. Abernethy in his Hunterian oration, will show. Mr. Lynn, who was for many years on intimate terms with Hunter, suffered a long illness in consequence of having wounded his hand in opening the body of a man who had died from a syphilitic affection. Hunter frequently called to see him, and one day, after expressing regret at his misfortune, and the obstruction it caused to his business, offered to lend him two hundred pounds, adding, that though he was the last man in the world to be able to do such a thing, yet that he would stretch a point, in consequence of the esteem he had for Mr. Lynn. His friend had been more prudent, however, than Hunter supposed, and did not then require assistance, but said, that should he have occasion for it he would not fail to apply to him. " Nay," said Hunter, " what I offer I will do now, but what I may be able to do a week hence it is impossible for me to say.'* On his recovery, Mr. Lynn went to thank him for his kindness. Hunter had forgotten the circumstance; " But," said he, " if I did say so, you may depend on it I meant what I said." But to resume the thread of my narrative. His old friend Jenner had long ere this sufficiently recovered from the effects of his first disappointment to plead his cause successfully with another lady, and he this year wrote to communicate to Hunter the news of the birth of his first child, to which he requested him to stand godfather; and as Hunter had no more intention than other godfathers of burthening himself with the performance of what he undertook, he readily acceded to the request, as will be seen in his reply. " Dear Jenner, [Post-mark, Jan. 29.] 17^9. " I wish you joy : it never rains but it pours. Rather than the brat should not be a Christian I will stand godfather, for I should be unhappy if the poor little thing should go to the devil because I would not stand godfather. I hope Mrs. Jenner is well, and that you begin to look grave now you are a father. " Yours sincerely, J. Hunter."

Two other letters of his, written in the early part of this year, to Jenner, show the diligence with which he promoted the interests of his friends; they relate to the admission of the latter into the Royal Society, of which body he was made a Fellow, in consequence of his interesting communication respecting the cuckoo. The first is as follows: " Dear Jenner, " You are to be balloted for next Thursday. 1 think there can be no fear of success. You shall have a letter from me by the Friday's post. " Yours sincerely, John Hunter. " I have wrote to Dr. Glass."

The second communicates the intelligence of his election. " Dear Jenner, London, Feb. 26th. " You was this evening voted into the Royal Society. You will have a letter THE LIFE OF JOHN HUNTER. 85 from the Secretary; but as that may not be sent for some days, I thought it would not be disagreable to have the earliest notice. " I am, dear Jenner, your most obedient, John Hunter."

His own contributions had, as we have before observed, become gradually more infrequent. The only paper he communicated this year was a supplement to his observations on the Wolf, Jackal, and Dog. To the Transactions of the Society for the Improvement 01 Medical and Chirurgical Knowledge he furnished a paper on intussusception, where he ingeniously explains the mode in which the several forms of the disease are produced. In the same volume is contained the account of Hunter's operation for aneurism, as before given in the Medical and Surgical Journal, and of a number of additional cases operated upon by Hunter and others. This paper was furnished by Mr. Home. In the following year he furnished to the same society a paper on Paralysis of the (Esophagus, and pointed out the mode of nourishing the patient, now commonly used in this and some other diseases, by means of a tube passed down the oesophagus. He also provided Mr. Home with the materials for another paper, on the formation of Loose Cartilages in Joints, the presence of which he satisfactorily explains by a reference to pathological preparations. In 1790 Mr. White, Surgeon-General to the colony of New South Wales, published a journal of his voyage to that country, to which is added an appendix by Hunter on the best mode of collecting and sending home animals, and on the nomenclature and classes of animals, as also a description of the kangaroo, and several other animals of that country. The following letter to Jenner relates principally to the subject of the presence of hydatids in the body, a phenomenon to which this gentleman, and his biographer Dr. Baron after him, have attached much importance, as giving rise in their opinion, to the formation of many kinds of morbid growth. " Dear Jenner, "I have just received the favour of yours. I have, just now, forgot the case of hydatids ; but if there was anything that struck me, I dare say it was laid by. They are frequently in the kidneys ; but I should doubt your oil of turpentine having any merit in bringing them away. My reason for supposing them animals is because they move after they have been extracted. I have taken them out of the head or brain of a sheep, and they have contracted in different parts of them when put into warm water. I should be glad to employ you if I knew in what, but if anything comes across my imagination I will think of you. The measly pork are hydatids. " I am afraid of your friend Mrs. L. There is a hard tumour that almost fills the pelvis, most probably the uterus. How does Mrs. Jenner do ? Do you bring her to London? What family have you got? My compliments to Mrs. Jenner; and believe me to be, dear sir, " Your most obedient and most humble Servant, "Dec. 8th, 1790. John Hunter."

Hunter's health had continued very precarious ever since his 86 THE LIFE OF JOHN HUNTER. severe attack of illness in 1785: in December 1789 he suffered under a sudden and entire loss of memory, which lasted halt an hour, and then as entirely left him. The spasms about the pnecordia were frequently re-produced by very slight causes, as trifling bodilv exertion or mental irritation. The latter cause was the most frequent, to which the uncontrolled hastiness of his temper rendered him particularly obnoxious; and so sensible was he of the risks to which it exposed him, that he was accustomed to say that " his life was in the hands of any rascal who chose to annoy and teaze him;" a painful thought, that one possessing a mind of such intellectual vigour should, from neglecting earlier to check this infirmity of temper, at length have allowed it " so to over-master reason" as to reduce him to hold his life on such a tenure. Notwithstanding, however, his ill state of health, Hunter continued to enjoy life ; his constant employment prevented ennui, and his natural vigour and courage enabled him to bear up against attacks which would have dispirited weaker minds. He does not seem, like his contemporary Dr. Johnson, to have been oppressed with a fear of death; but neither had he, any more than the great moralist, any longing to " shuffle off this mortal coil;" and when a gentleman at his table spoke of Dr. Hunter's expressing, in his last moments, a feeling of satisfaction in dying, Hunter replied, " Ay, 'tis poor work when it comes to that." Indeed, he had sufficient reason for being anxious that his life should be prolonged. As yet he had made no provision for his family; and his museum, on which he had expended so much, and to the sale of which he chiefly looked as the source of such a provision, was as yet greatly deficient in proper catalogues, a want which could not but greatly detract from its value, and to supply which formed one of the chief objects of his attention during the remaining years of his life. Although Hunter considered his pursuits too important to allow of his devoting much of his time to general society, yet he was hospitably disposed, and, as soon as his income allowed of it, lived in rather a handsome style, kept a carriage and footman for Mrs. Hunter, entertained his friends at dinner, and opened his house to his medical acquaintances every Sunday evening. His house at Earl's Court had been gradually improved and enlarged since his marriage, and some of the rooms had been tastily fitted up under Mrs. Hunter's direction ; the drawing-room, in particular, was ornamented with moveable panels, elegantly painted in water-colours, and representing the story of Cupid and Psyche. Here he used to spend a good part of his time during the autumnal months, returning to London in the morning after breakfast, and retiring to dine and sleep with his family at Earl's Court. The grounds were, as usual, stocked with various denizens of earth and air, collected from all quarters of the world, and the garden was well furnished with wall fruit; but this was considered the sole property of his bees, several hives of which were contained in the conservatorv, where he used to pursue his observations whilst at home, and leave THE LIFE OF JOHN HUNTER. 87 some of his family to mount guard during his absence. His fondness for bees was very great, from whence he derived a common but expressive metaphor, which he was in the habit of employing, that " his head was like a bee-hive." When residing in London his establishment was very numerous, and as he had generally workmen engaged about the premises, not less than thirty persons usually sat down to dinner in his house. In conversation he seldom displayed wit; but his remarks were often wonderfully pointed and forcible, and showed him to be an original thinker. In politics he was as strenuous a Tory as Dr. Johnson or the renowned Christopher North could have desired, and was not more lenient than they towards those who differed from him in opinion. He used to say, that " he wished all the rascals who were dissatisfied with their country would be good enough to leave it." He had a great dislike, as may be easily imagined, to taking part in any public procession or displays of any kind, and fairly wished Sir J. Reynolds and his friends at the d—1 when called on to take part in the funeral of this eminent artist and delightful author.* In 1792 Hunter contributed'his last paper to the Philosophical Transactions. This contained the results of his observations on the hive bee, continued, with various interruptions, during a period of twenty years. The variety of his employments rendered it impossible that he should devote such continuous attention as some others, and especially Huber, have since done to the habits of these very interesting animals; nevertheless, his keen observation did not fail to detect several errors which preceding naturalists had fallen into, especially with regard to the formation of the wax, which he proved to be secreted, not collected, by the animal; and on the whole his paper added largely to the general stock of knowledge respecting the economy of the bee. He had not confined his attention to the hive bee only, but intended, as will be seen by the following letter to Sir J. Banks, which accompanied his paper, to treat also of the hornet, the wasp, and

* Hunter, with Sir G. Baker and Mr. Home, attended Sir J. Reynolds in his last illness, the nature of which was very obscure, and is said not to have been understood until a fortnight before his death, when it was ascertained to depend on enlargement of the liver. The following is a copy of the post mortem examination, the original of which is in the possession of my friend Mr. Palmer, the great-nepheiw of Sir Joshua, and editor of the present edition of Hunter's works. "In examining the body of the late Sir Joshua Reynolds, we found no marks of disease in the cavity of the breast, except only a slight adhesion of the lungs to the surrounding membrane on the left. side. " In the cavity of the belly the only diseased part was the liver, which was of a magnitude very uncommon, and at least double of what is natural: it weighed eleven pounds, and was of a consistence which is usually called scirrhous. It had lost its natural colour, and become of a pale yellow. " We found the optic nerve of the right side shrunk, and softer than natural. There was more water in the ventricles of the brain than what is generally found at so advanced an age. ~2Mh Feb. 1792. G. Baker, John Hunter, E. Home." 88 THE LIFE OF JOHN HUNTER. several of the solitary bees; and we cannot but greatly regret that his intentions were left unfulfilled. "February 21, 1792. "Sir,-A11ow me to present to you a paper on thPj natural h/.s*'y o^?^ mon bee. It contains the result of experiments and *n™Uo™^^™l made in the course of the last twenty years. They have been frequentlyMnter rupted by my other pursuits, which prevented me from follow »"S t!l'^ ^"V™ regularly through any one season, and consequently obliged me to renew i; n others. Unforeseen accidents have considerably retarded my progress . a very sultry day melting the comb, the bees removing some eggs or magpote, o :a hive dying under experiment, have destroyed the chain of my observations lor a

W"ietwas°my intention to have added some remarks on the management of bees in this country, but I am induced, from the length of this paper, to reserve them for another opportunity. If you and your learned Council think them worthy the attention of the Royal Society, I shall hope to have them honoured with a place in your valuable Transactions. /..,•.■, r " As I have gone a considerable length into the natural history of this tribe of insects, I hope next winter to give you the account of the wasp, and probably the hornet. I shall afterwards be able to give the wild or humble bee, and many of those called solitary bees, in which I have made considerable progress; and in time I hope to complete the history of the British bees. " I am, Sir, your much obliged and most humble Servant, "Leicester Square, John Hunter. "To Sir J. Banks, Bart., P.R.S." He this year resigned to Mr. Home the office of delivering his surgical lectures, and for this purpose passed over to him all his manuscripts, the greater part of which have unfortunately been either lost or destroyed. On the fly-leaf of each of these lectures were inscribed references to the different preparations which he employed for the illustration of his opinions, which, did they exist, would manifestly afford great aid in determining the specific object of many of these preparations. The loss of these lectures has been lately remedied in part by the publication of the late Mr. Parkinson's notes of them by his son, under the title of " Reminiscences of John Hunter;" and Mr. Palmer will be able, in the present edition, still further to repair the loss, by collating a number of copies, of different dates and by different hands, with each other. To this foundation furnished by Hunter, Mr. Home added a number of new lectures on particular diseases, and on the operations of surgery, which he continued to deliver for a few years, but was never a very popular or diligent lecturer. Mr. Hunter's chief reason for declining his lectureship at this time was, that he might have more leisure to devote to the completion of his work on Inflammation, which, in justice to himself, he felt it was now time he should make public. As it happened, he did not live to see the entire work through the press, a portion of it still remaining at the time that he died, the office of correcting which devolved on Mr. Home and Dr. Baillie. It was published in 1793, together with a life of the author by Mr. Home. This work is one on which, above all his other writings, Hunter's fame has hitherto rested; perhaps too exclusively so, since it has THE LIFE OF JOHN HUNTER. 89 arisen from the circumstance that, with the exception of the treatise on syphilis, his other works have been less generally read than they deserve, in consequence of their having been published either in an expensive form or in detached treatises, scattered through the volumes of the Philosophical Transactions, or of the Medical and Chirurgical Society. There are not, however, any of his writings which do not well deserve the attentive perusal of professional men, not only for the information they furnish, but as models of bold and sagacious reasoning; and hence the present edition, which places within the reach of every professional man the whole of his works, heightened, too, in value by the commentaries of the able men to whose revision they have been severally entrusted, cannot fail to be viewed as a tribute justly due to the merits of Hunter, and as a highly important accession to our medical literature. The Treatise on Inflammation and Gunshot Wounds must be considered as comprising the results of forty years' assiduous attention to the subject, since, from his Introduction, we learn, that the doctrines it unfolds first suggested themselves to his mind at the time he was a student in the London hospitals, and were based on observations collected during that period. .These doctrines he continued during his whole professional career to submit to the test of his own increasing experience and the experience of others, to whom he taught them in his lectures, ever carefully and candidly correcting them where more accurate observations proved them to be faulty, and extending them where fresh information showed them to be deficient; and having thus brought them to as high a degree of perfection as his abilities and opportunities would permit, he at length submitted them to the test of public opinion in the condensed and systematic form in which we now possess them. Notwithstanding the time and attention he had devoted to the completion of a work on which his future fame was mainly to depend, he was himself fully sensible of its still possessing many defects, and rather desired it to be considered " as a new figure composed from rough materials, in which process little or no assistance could be had from any quarter," than as a perfect work which no further experience could have amended. It must indeed be acknowledged that it does, in many parts, exhibit imperfections of style and diction, as well as repetitions, which not unfrequently obscure the author's meaning; and illogical errors, such as that of confounding proximate and final causes, or employing such imaginary causes as the " stimulus of necessity," " the stimulus of death," "the force of a negative impression," &c, to account for certain effects; phrases which cheat the ear with a seeming explanation, but leave the mind no whit the wiser as to the real causes of the phenomena to be accounted for. These defects, though they do unquestionably detract somewhat from its value, are, however, trifling in comparison with the great and varied excellence of this work, which, for the originality and variety of its experiments, the accuracy of its observations, and the importance of its deductions, 10 90 THE LIFE OF JOHN HUNTER. can with difficulty be paralleled in the whole range of medical liter-

Ab'out this period the London Veterinary College was first projected, and being liberally supported by several influential noblemen, was speedily established. Hunter felt much interest in its formation, and, with several other gentlemen, took shares in it to the amount of two hundred pounds, and, furthermore, granted to the pupils attending there a free admission to his lectures. In addition to the honorary distinctions which he before enjoyed, Hunter had this vear conferred on him the title of Member of the Irish College of Surgeons, and of the Chirurgo-Physical Society of Edinburgh; but neither these nor any others did he ever append to his name, preferring the simple appellation of John Hunter, which he was fullv conscious was better able to confer honour on most Societies than their initials to add importance to it. We have now arrived at that period when it becomes necessary to notice the unhappy disagreements which had for some time past existed between Hunter and his colleagues at the Hospital, and which now broke out into more decided measures of hostility. It would have been more agreeable, had it been proper, to have passed over these without notice, since they reflect little credit on either of the contending parties; but they are so intimately connected with the fatal event which terminated Hunter's life and labours, that it seemed absolutely necessary, in the present narrative, to notice them somewhat more fully than his former biographers have done. [Mention has alre.idy been made of the blunt and overbearing, manner which Hunter not unfrequently displayed towards men of his own standing in the profession. Devoted as he was to physiological pursuits, and firmly persuaded that without an improved knowledge of physiology it would be impossible to attain to correct general principles in surgery, which he looked on as still in its infancy, he viewed with contempt those who were content to guide their practice by past experience alone, or by the erroneous theories of their ancestors. On the other hand, the majority of Hunter's contemporaries considered his pursuits to have little connexion with practice, charged him with attending to physiology more than surgery, and looked on him as*little better than an innovator and an enthusiast. There could be little harmony between such discordant elements, and as it was with his colleagues at the hospital that Hunter most frequently came into collison, it was between him and them that mutual want of respect most easily and surely ripened into animosity. At the commencement of 1792, Hunter's colleagues at the hospital were, Gunning, who was his senior, a man of good talents and high spirit, and leader of the opposition against him ; Walker; and Charles Hawkins, the son of Sir Cassar, and a remarkably dexterous operator. Early in the year Hawkins resigned his situation, and a contest for the vacancy ensued between Keate and Home. THE LIFE OF JOHN HUNTER. 91 The latter was of course supported by Mr. Hunter, whilst all the remaining medical officers, with the exception of Dr. Baillie, lent their interest to his opponent. The contest was perhaps the warmest in the annals of hospital electioneering, and several of the Royal Dukes attended in person to vote for Mr. Keate, who was chosen by a majority of 134 against 102. A contest like this, however it might have ended, could scarcely fail to heighten existing animosities; and soon after, Hunter, actuated far more by a spirit of hostility to his opponents than by any desire of pecuniary benefit to himself, announced to them his intention to discontinue the practice of dividing equally amongst the surgeons the admission fees of all the pupils attending the hospital, and for the future to retain for himself the money of those who should enter under his name as pupils; a preference which is determined by various circumstances, and which has never been regarded in any other light than as a compliment. As a reason for this step, he alleges his wish to stimulate the other surgeons to pay some attention to the education of the pupils, which, as he asserts, they were far from doing, but on the contrary had brought disgrace on the hospital by their neglect. This measure his colleagues resolved to resist, and determined to submit the matter to the decision of the Governors, a step which seems, from the following letter, to have met with Hunter's full concurrence.

" Gentlemen, " As the time approaches when you propose referring to the Governors of St. George's Hospital my determination respecting the money arising from the surgeons' pupils, I beg leave to acquaint you that I entirely agree with you in the mode that you have proposed, a mode I did not myself adopt, as it took from you the power of acceding to my proposal, and made me appear to the Governors as an accuser. But when you bring it before them I shall meet it fairly and very willingly. " I am, gentlemen, your most obedient servant, " Leicester Square, Feb. 8, 1793. John Hunter." " Messrs. Gunning, Walker, and Keate.

A Special Court was accordingly summoned to meet in March following. Before the day of meeting, Hunter forwarded to each subscriber, for his information, a pretty long prjnted letter, explanatory of his reasons for the alteration which he had determined to make. In this communication, wjiich is certainly not remarkable either for its liberality or modesty, he gives an account of the various efforts he had made, since his connexion with the hospital, to induce his colleagues to improve the system of instruction; efforts which, he says, all proved ineffectual: one man " did not choose to hazard his reputation by giving lectures," and another " did not see where the art could be improved." Disgusted at his want of success, and resolving not to encourage the indolence of others, he had consequently slackened in his attention to the pupils, and an immediate and constant falling off in their numbers had been the result. He shows how large a majority of the whole number of 92 THE LIFE OF JOHN HUNTER. students had always entered as his pupils, argues on the propriety of each surgeon profiting according to his labours, and therefore justifies his present intention, which cannot justly be ascribed to any avaricious feeling, seeing that the whole number ot those entering at the hospital is now so small. Finally, he deprecates the considering this as a party question, affirms that he is actuated by the most disinterested feelings, and expresses his readiness to submit to the decision of the Court. To this letter the hostile triumvirate replied, by denying the correctness of Hunter's account. The increase of pupils after his accession to the hospital, they attribute to the breaking out of a war, and not to his presence; the subsequent decrease they state was caused by the establishment of medical schools at the other hospitals, and'not by Mr. Hunter's neglect. They admit that the number of pupils entering with him has been larger than with either of themselves ; but this has been owing to his connexion with the anatomical school in Windmill-street^ and his power of conferring posts in the army, and not to his superior attention to the pupils. To the charge of neglecting their duty, brought against them, they reply by stating that they have continued the usual plan of instruction long followed in the hospital. That if the students have neglected their duties there to follow physiological researches, it was not their fault. A proposal they state had been formerly made, that each of the surgeons should give six lectures at the hospital, for which extra instruction the admission fee was to be raised from twenty to five-and-twenty guineas, but for the following rather curious reasons the plan was not put into execution. 1st, Because they thought the old plan of instruction best for surgeons. 2dly, Because copies of the lectures might be taken by the pupils, and might get abroad ! 3dly, Because, though the pupils might be pleased for a course or two, the lectures would lose their effect ultimately, and might, from the number being lessened, in consequence of the rise of price, in the end prove disadvantageous. They then go on to show, that a manifest disadvantage to the pupils would arise from the proposed measure ; for whereas they had hitherto enjoyed the benefit of instruction from all the surgeons, they would for the future be limited to the instruction afforded by the surgeon alone under whom they entered, should Mr. Hunter's intention be carried into effect. The decision of the Governors was given against Mr. Hunter; for though his opponents neither fully disproved his statement, that he had been the means of increasing the number of pupiis at the hospital, nor could deny that he had done more towards their instruction than any of themselves, yet the disadvantage of the plan he proposed was so obvious, as pointed out by his opponents, that nothing but confusion and discord could have been expected from its adoption. A Committee was subsequently appointed to draw up a.code of rules for regulating the admission and instruction of pupils; and a set of proposals was submitted to them by Mr. THE LIFE OF JOHN HUNTER. 93

Hunter's colleagues, which was agreed to without his having been even consulted on the occasion ! Many of the regulations adopted continue in force to the present day; others, and especially those relating to the better instruction of the pupils, soon fell into disuse; and some seem to have been especially directed against Mr. Hunter. Amongst these latter was one which determined that for the future no person should be admitted as a student of the hospital without bringing certificates that he had been educated to the profession ; a regulation which was probably designed to exclude Mr. Hunter's countrymen, who sometimes came up to town recommended to him, and entered as his pupils at the hospital, without having had any previous medical instruction. Nor was this clause long in taking effect: for in the autumn, two young men, who had come up to town ignorant, of this new regulation, applied to Hunter to be admitted under him at the hospital. He informed them of the law which had been passed, but undertook to press for their admission at the next Board-day, and directed them to furnish him with a statement of their case in writing. On the 16th of October the Board was to meet, and Hunter prepared to fulfil his promise, though he was so well aware of the risk he incurred, in undertaking a task which he felt would agitate him, that in mentioning the circumstance to a friend who called on him in the morning, he expressed his apprehension lest some unpleasant dispute might occur, and his conviction that if it did it would certainly prove fatal to him. At his accustomed hour he left his house to commence his morning rounds, and by accident forgot to take with him his list of appointments ; he had left the house but a few moments when it was discovered, and Mr. Clift, who was then residing in his house, hastened with it to York-street, St. James's, the first place on the list, where he found the carriage waiting. Hunter soon made his appearance, took the list, and in an animated tone called to the coachman to drive to St. George's. Arrived at the hospital, he found the Board already assembled, and entering the room, presented the memorial of the young men, and proceeded to urge the propriety of their being admitted. In the course of his remarks he made some observations which one of his colleagues thought it necessary instantly and flatly to contradict. Hunter immediately ceased speaking, retired from the table, and struggling to suppress the tumult of his passion, hurried into the adjoining room, which he had scarcely reached when, with a deep groan, he fell lifeless into the arms of Dr. Robertson, one of the physicians of the hospital, who chanced to be present. Dr. Baillie had immediately followed him from the Board-room, and Mr. Home, who was in the house, was also summoned to his assistance. Various attempts were made for upwards of an hour to restore animation, under the hope that the attack might prove to be a fainting fit, such as he had before experienced, but in vain; life had fled ; and all their efforts proving useless, his body was placed in a sedan chair and conveyed to Leicester-square, followed by his now vacant carriage, 10* Dl THE LIFE OF JOHN HUNTER. This most distressing event of course put an end to the business of the meeting: the Board broke up, and the only notice to be . found on the books of that day's proceeding is the following minute: " Resolved,—That Mr. Hunter's letter to this Board relating to two of the surgeons' pupils, which was received this day, be preserved for future consideration." The body was examined after death,* when the viscera of the belly and head were found loaded with blood, but otherwise nearly in a natural state, with the exception of the carotid arteries and their branches within the skull, which were in parts thickened and ossified. In the chest, the left lung had become attached to the costal pleura by old and firm adhesions ; but the heart was found to be the chief seat of disease. The pericardium was unusually thickened, but did not contain much fluid. The heart itself was small, appearing too little for the cavity in which it was contained, its diminished size being the result of wasting, and not of strong contraction of its fibres" Two opake white spots were seen on the left auricle and ventricle. The muscular structure of the organ was pale, and loose in its texture. The coronary arteries had their branches which ramify through the heart converted into long tubes, with difficulty divisible by the knife. The mitral valves were much ossified. The aorta was somewhat dilated, its valves thickened and wanting pliancy, and the inner surface of the artery was studded with opake and elevated white spots. Hunter's body was interred in a private manner, in the church of St. Martin-in-the-Fields, accompanied only by a few of his medical friends. • Some time after his death Mrs. Hunter felt anxious to erect a monument to his memory in Westminster Abbey; but the fees demanded for a permission to occupy a niche within that venerable fane were too great for her reduced fortunes, and she therefore abandoned her intention. It may be thought that the author of the Hunterian museum needs no other memorial of his worth than the proud one he has himself erected ; nor does he, to perpetuate his fame: still it would be a fitting act of respect to his memory, from those who enjoy the benefits of this rich legacy of his genius, to enrol his name amongst those of the other gifted men whose worth stands recorded in Westminster Abbey. Thus, in his sixty-fifth year, died John Hunter, celebrated alike as a surgeon and as a naturalist; in either of which capacities has he had many equals,—in his combined character, none. In person he was about the middle stature of a vigorous and

• It has been supposed by some that Hunter had the same antipathy to the scalpel of the anatomist as was felt by his brother ; but this was by no means the case ; on the contrary, he always spoke of it as a matter of course, and used, in the strongest language, to express his condemnation of those who should neglect to examine his body and preserve his heart. It is to be regretted that no relic of this sort has been preserved. THE LIFE OF JOHN HUNTER. 95 robust frame, and free from corpulency ; his shoulders were high, and his neck short. His features were rather lage, and strongly marked; his eyebrow projecting, his eyes of a light colour, his cheeks high, and his mouth somewhat under-hung. In dress he was plain and gentlemanlike ; and his hair, which in youth was of a reddish yellow, and in his latter years white, he wore curled behind. On considering what was the distinguishing character of Hunter's mind, we perceive that it was rather that of general strength and vigour than of marked predominance of any one faculty, especially adapting it for excellence in some particular kind of pursuit. Johnson says " a true genius is a mind of large general powers, accidentally determined to some particular direction;" a definition which, though certainly not universally true, seems thoroughly descriptive of "Hunter's mind. To talents for observation naturally acute, and heightened to an extraordinary degree by constant practice, Hunter added strong reasoning powers, a sound judgment, and an imagination which, though not brilliant, was sufficiently active to aid him in his researches, whilst it rarely drew him far aside from the sure paths of induction into the regions of hypothesis. Hence, though it might be difficult to name any employments better fitted to call the faculties of his mind into full action than those in which he was engaged, yet it cannot he doubted that there were many in which those faculties, aided by his extraordinary powers of application, would have as certainly raised him to a pre-eminence above other competitors as they did in medical science and natural philosophy. With regard to Hunter's moral character, though it was adorned ; with many noble features,—as undeviating honesty, an eminent love of truth and candour, and a humane and generous spirit,*— and though as a friend he was warm and disinterested, and as a husband and a parent kind and affectionate, yet his character was defective for want of that control over his passions and his temper, the possession of which is absolutely necessary to the attainment of moral excellence and true happiness. It is related of Mr. Pitt, that when asked in his last illness by the Bishop of Lincoln if he had any objection to receive the sacrament, - he replied, " None whatever. I will take it readily,, if you wish; but, my dear Lord," he added, " the whole of my life has been devoted to Politics; and as I have had no time to attend to religion, I must now trust to the mercies of God." As regards his attention to the all-important subject of Religion, it is to be feared that a

* In regard to fees Hunter was extremely liberal. He used generally to reply, when asked to say what was due to him, " Why, that you must determine yourself; you are the best judge of your own circumstances, and it is far from my wish to deprive you of the comforts of life." He never allowed himself to accept any remuneration from non-beneficed clergymen, professional authors, or artists of any sort, and sometimes returned large fees when he found that the parties were in embarrassed circumstances. « 96 THE LIFE OF JOHN HUNTER. similar answer must have been given to a like question by Hunter, whose mind had been directed with no less intensity and devotedness to his peculiar pursuits than had that of the great statesman before mentioned. , In forming an estimate of Hunter's professional character, and of the influence which his labours have had on the improvement of surgery, we are not, as with ordinary minds, simply to enumerate the various practical amendments of which he was the immediate author. His claims are of a far higher nature; and in as much as he was the first who taught us to bring the lights of physiology to bear upon the practice of our art, and by his writings, his teaching, and his example stimulated the minds of numerous able followers to pursue the track he had pointed out, he justly merits to be considered as the author of a new aera in the history of our profession. In the character of a naturalist it is impossible for us 1o form a full estimate of Hunter's labours, either from his published works, or from his incomparable Museum as it at present stands. In the course of the numberless dissections, which he prosecuted during thirty years of unwearied diligence, he necessarily made a great variety of isolated observations, which, though not immediately applicable to the objects he had in view, would doubtless have constituted important contributions to the general stock of knowledge in comparative anatomy. Such observations he always recorded carefully in appropriate volumes; but by Sir Everard Home's extraordinary destruction of his manuscripts science has been deprived of these fruits of his industry, of which scarcely the smallest portion now remains in existence. But even in cases where the records of his researches have been preserved, either in the form of preparations or by means of drawings forming part of his museum, the want of proper descriptive catalogues has often caused them to be overlooked, whilst more modern naturalists have been reaping the honour of discoveries which were due in the first place to Hunter. Nevertheless, though we cannot estimate the full extent of his labours, enough remains to entitle him to a place in the highest rank as a natural philosopher.* His various papers in the Philosophical Transactions and elsewhere give sufficient evidence of the original and masterly manner in which he handled every subject of

* The following extract from the obituary of Hunter, in the Gentleman's Magazine, is much more flattering to the author, and affords a curious specimen of the stuff which these memorials often consist of:—" .... As a man of letters independently of his profound scientific studies, he had traced the practice of surgery to the earliest ages. He was well acquainted with every practitioner mentioned by Pliny, with all the Greek and Roman authors who had written on the subject, as well as with every modern one who had contributed to the perfection of the art.....As a man well versed in ancient history, the Egyptian chronology was familiar to him, as far as related to the antiquity of anatomy • as a scholar, distinguishably classic, he knew that Homer was an anatomist at least had ideas of anatomy, as well as an epic poet," &c—One would imagine that the biographer had purposely selected the weak points of Hunter's character, in order to parody them. THE LIFE OF JOHN HUNTER. 97 inquiry; and the arrangement of some departments of his museum shows, that whilst his great contemporary Linnaeus was extending and perfecting his beautiful but artificial arrangement of living objects, Hunter had made considerable advances towards that natural classification of the animal world which Cuvier has so admirably effected in modern times. By his will, of which Dr. Baillie and Mr. Home were the executors, Hunter bequeathed the estate of Kilbride to his son. Earl's Court he directed to be sold; and the proceeds, after payment of his debts, to be divided equally between his widow and two children. His Museum he ordered to be offered, in the first instance, to the British Government (therein following the example of his elder brother), and on such terms as might be considered reasonable; and in case of their refusing it, he directed it to be sold either to some foreign state, or in one lot, in such manner as his executors might think proper. On examining, however, into the state of his affairs, it was found that his property, exclusive of the Museum, would scarcely suffice to pay his debts; and it was accordingly to the produce of the sale of this that his family had to look for their future support. The disposal of it to the British Government was on all accounts most eligible: but it was no easy task to bring this about. The attention of Parliament and the nation was wholly directed to the events of the French Revolution, and there was a great unwillingness to expend money on any objects not essential to the conduct of the war. When Mr. Pitt was appliedpto on the subject, his reply was, " What! buy preparations! Why I have not money enough to purchase gunpowder." And it was not until three years after that Parliament could be induced even to institute an inquiry into the value of the Museum, with a view to deciding how far it might be desirable to make it national property. In the mean time Hunter's family were in very straitened circumstances. Through the kind interposition of Lord Auckland, Mr. Pitt was prevailed on to bestow a portion of His Majesty's bounty on Mrs. Hunter during the first two years of her widowhood; but the Act of Parliament forbade its being given a third year. The greatef part of Hunter's household goods were therefore sold to meet the current expenses of his family and pay for the conservation of the Museum;* and

* Amongst these were a variety of valuable objects of virtu which Hunter had collected from various quarters; ancient coats of mail, weapons of various dates and nations; and a very beautiful turning lathe, which had belonged to the Duke of Cumberland. With such articles as these Mr. Christie, the fashionable auctioneer of the day, who presided at the sale, found himself quite at home ; but when he came to dispose of a curious mask, which Hunter had constructed to protect his face whilst making his observations on bees, the renowned auctioneer was completely non-plused. At length, after turning it round and round, and surveying it on all sides, he said, "This, ladies and gentlemen, is a covering for the face, used by the South Sea islanders when travelling, to protect them against the snow storm.i.,,\ It would appear from a sale catalogue (in the possession of Mr. Upcott), dated July 31, 1794, to which the prices are affixed, that the produce of this sale could not have been considerable. 98 THE LIFE OF JOHN HUNTER. it is to be regretted that amongst these were included his library," and a valuable collection of crystallizations, both of regular and irregular forms, which he was accustomed to use in his lectures to exemplify the difference between the laws which regulate the growth of organic and the increase of inorganic bodies. Whilst, however, we must regret that these objects were irretrievably dispersed, we must entirely exempt his executors from the blame which has been sometimes attached to them for allowing this to take place. Neither of them were in circumstances to defray from their own resources the expenses necessary for the maintenance of his widow and children; and as there seemed little prospect of soon disposing of his collection, they were obliged to have recourse to the sale of objects which, under other circumstances, they would have gladly held sacred.f In 1796, all the personal efforts of Hunter's executors having failed to induce the House of Commons to think of purchasing the Museum, Lord Auckland kindly undertook to interest himself in the affair, and accordingly applied, in the following letter to Sir J. Banks, to know how far he would be disposed to lend'his assistance in calling public attention to the subject:

* It has already been observed that Hunter found he could employ his time more profitably in studying nature than in reading books, whence it arose that his library was small, and consisted principally of presentation copies. Its dispersion would not of itself have been a subject of regret, if it were not that Mr. Hunter was in the habit of annotating largely in the margins of those books which he read. He has made references to Bcrelli, Hamberger, Goddard, Glisson, Swammerdam, &c, in his Croonian Lectures, which he would probably not have done if he had not carefully consulted these authors. f These difficulties were entirely removed, after some years, through Dr. Garthshore's kind interference. He engaged Mrs. Hunter, whose exemplary conduct during her widowhood had gained her the esteem of all parties, to reside in the house of two young ladies of large fortune, who were wards of his, where she continued until her death in the receipt of a very handsome salary. Durinor this time she published a volume of poems, which possess considerable merit as light compositions. In 1804 she composed the following Epitaph, with the design of having it inscribed on a marble tablet to be placed over the remains of her late husband in St. Martin's church ; a design, however, which it was intimated to her by Dr.#Hamilton, the rector, was contrary to the rules of the church:

" Here rests in awful silence, cold and still, One whom no common sparks of genius fired ; Whose reach of thought Nature alone could fill, Whose deep research the love of Truth inspired.

" Hunter ! if years of toil and watchful care, If the vast labours of a powerful mind To soothe the ills humanity must share, Deserve the grateful plaudits of mankind,__

"Then be each human weakness buried here Envy would raise to dim a name so bright: Those specks which in the orb of day appear, Take nothing from his warm and welcome litrht. " Anne Hunter." THE LIFE OF JOHN HUNTER. 99 " Eden Farm, near Bromley, Kent, Jan. 25, 1796. " My dear Sir, " I wish, in the fewest words possible, to engage your attention to a subject interesting both to friendship and philosophy. I know that the pleadings of two such advocates will be most congenial to your feelings. " Our late friend John Hunter left nothing for the support of his widow and children, after the payment of his debts, but his collection of comparative preparations. From respect for his memory, and from regard for Mrs. Hunter, whose conduct in such a position has been highly becoming, I have concurred with the Chief Baron during two years in obtaining for her, through Mr. Pitt, the aid of His Majesty's bounty; and I have been of some use to her in other respects. But the Act of Parliament does not allow the King's bounty to be given a third year. In the mean time the Trustees of the Collection (Mr. Home and Dr. Baillie) have not been able to induce the House of Commons to purchase it, or even to consider the subject. In truth, the agitations of their minds amidst the great scenes which are going forward, as well as a general impression that all avoidable expenses not essential to the purposes of the war should be postponed, have combined to make it difficult to recommend the purchase to the public. The delay is most distressing to the family, who have no other resource: the mere expense of keeping the collection is an overwhelming weight to those who have nothing. "I do not pretend to be able to form any adequate idea of the value and importance of the collection to science ; it is quite out of my line of observation. But I have always understood that you scientific leaders concur in thinking it highly curious, and well calculated to do service in the school both of medicine and of natural philosophy in general. " I trust that as the worthy President of the Royal Society, as an old and respected friend of a distinguished person whose family is left destitute, and, in short, as a man of science and" of benevolence, you will turn this subject in your thoughts. If the purchase could be properly and effectually recommended, with the King's approbation, to the House of Commons and to the Minister at the head of the Treasury, it would be the best result. " If you would like to have a consultation at your house of any number of Mrs. Hunter's friends, and of persons of other descriptions, I shall be glad as an individual to attend your commands in Soho-square. I propose to return to town about the middle of next week. " I wish you would re-settle the seasons, which seem to be under a revolutionary government. I do not remember an instance of so long a prevalence of southern gales in the depth of winter. " Believe me, my dear Sir, most sincerely yours, " Auckland."

In his reply to this application Sir J. Banks, as will be seen, expresses his willingness to take part in endeavouring to bring about the desired purchase of the Museum ; but at the same time seems to intimate that the College of Surgeons had been backward in interesting themselves on the subject, although they were the parties to whom it would prove flhost serviceable.

" My dear Lord, "Had I thought my friend John Hunter's collection an object of importance to the general study of natural history, or indeed to any branch of science except to that of medicine, I hope that two years would not have elapsed without my having taken an active part in recommending to the public the measure of purchasing it. I was consulted in the first instance by the gentlemen concerned, who, if I rightly understood them, agreed with me in thinking that the history of diseases was the only interesting and valuable part, and the natural history was not of consequence sufficient to be brought forward as an object of public purchase. 100 THE LIFE OF JOHN HUNTER. " Concluding that the history of diseases arranged itself naturally under the protection of the College of Surgeons, and knowing that the corporate mansion of that learned bodv was roomy enough to receive the collection; being well aware that the matters of abstract medicine did not come within the province o! the Royal Society, knowing that the apartments of that body are scarce able to contain the property they already possess, and thinking the museum, to which, from the nature of its institution, students could not have a convenient access, an improper deposit, I declined with the full approbation, as I thought, ot the parties concerned, taking any lead in the matter. " Regard for my deceased friend, however, has always made me desirous ot doing all I could do, without interfering too much in a business evidently out of my province; I offered, therefore, at that time all the secondary assistance in my power. I shall be happy, therefore, whenever your Lordship or the Chief Baron, who have hitherto taken the lead in this business, do me the honour to think 1 can be of use, to obey either of your summons, and meet you when and whenever either of you shall choose to appoint."......

Soon after this the question was at length properly brought before the House, when a Committee was appointed to take the petition of Dr. Baillie and Mr. Home into consideration, and to inquire into the value and probable expense of keeping up the Museum. - Several of the most eminent physicians and surgeons, as well as other scientific men, were examined, who strongly recommended the purchase of the collection, which they estimated at a much higher value than 15,000/., the sum named for it. The Committee having satisfied themselves on this point, and made a report to the House, the above sum was voted by Parliament on the 13th June 1796. Instead, however, of being immediately transferred to the Corporation of Surgeons, it is reported that an offer of the collectio'n was first made to the College of Physicians,* who, foreseeing the expense of maintaining so large a number of preparations, demurred to accept it, unless accompanied with such additional grants of money and lands as should be adequate to its support. The disinclination which was thus manifested by the College of Physicians to become the guardians of this noble collection, and to incur those public and private liabilities which were necessarily incident to the charge, might equally have been justified on.',the part of the Surgeons. The funds of the Corporation of Surgeons at this period were in an extremely low state; nor were the fame and public reputation of this body in a much more flourishing condition. It is therefore greatly to the credit of the Council of this Body that they came to the unanimous vote, on Dec. 23, 1799, to accept the Museum on the terms proposed by the Government, especially when we reflect that the costs for maintaining and augmenting the Collection, up to August 1833, amounted to not less than 36,000/. It would manifestly, however, have been in the hio-hest decree improvident in the Surgeons to have acceded to °the offer of Government, with the conditions annexed, if they had not foreseen some method of replenishing their finances. This method consisted * It would appear also, from a letter addressed by Dr. Baillie and Mr Home (Nov. 1799) to the Lords of the Treasury that thoughts were afterwards entertained of making it a part of the British Museum. THE LIFE OF JOHN HUNTER. 101 in obtaining a new charter from the Crown, which should entitle them a Royal College, with permission to examine for diplomas; and in this hope they were not disappointed. In the course of the ensuing year a charter was obtained; and although the applicants for diplomas during the first two years did not amount to more than 300, yet this number had increased to 770 in the two years ending August 1833 ; and the average receipts to the College derived from this source alone, during this latter period, did not amount to less than 11,116/. per annum. This increase of public reputation, and consequent wealth, must no doubt mainly be attributed to the celebrity which necessarily accrued to the College from possessing a new charter, and from being appointed the public guardians of the Hunterian Collection. It would be unjust, however, not to say that these circumstances alone would have been insufficient to attain the objects in view, if they had not been strongly supported by the zeal and talents of several members of the Council, who more particularly interested themselves in the management of the affairs of the College at that period. This valuable collection was not entrusted to the Corporation of Surgeons unfettered by conditions ; and that these conditions might be duly performed, a Board of Trustees was appointed, whose duty it was to supervise the general management of the collection. The principal of these conditions were,— "1. It was incumbent on tne College to preserve the collection in the best possible state at their own expense. " 2. That the collection should be open to the inspection of the* Fellows of the College of Physicians and the Iflfembers of the Company of Surgeons, and persons properly,introduced by them, four hours in the forenoon two days every week. "3. That a catalogue should b^Vnade of the preparations, and a person appointed whose business it should be to explain it to such persons as visited the cqlle^flon. "4. That a coursgp%f twenty-four lectures on comparative anatomy, &c, shodlrDe delivered annually at the College." The admirable manner in which the first and last of these conditions have been complied with will not be questioned by any one who has visited the Museum or attended the lectures. As for the second and third, as it is impossible to offer praise, so it may be more prudent to refrain from animadversion. The parties who were most to blame in this business have long since gone to another tribunal, and any comment upon this subject would be useless. 11 102 THE LIFE OF JOHN HUNTER. CHAPTER VII.

The museum of Hunter having been entrusted by Government to the care of the College of Surgeons, the Council, in July 1800, appointed from their body a Board of Curators, consisting of seven members, to whom was given the charge of superintending the preparation of catalogues of the objects in the collection, and of drawing up regulations for its management. During the first six years the collection remained in the gallery in Castle-street, which had been built by Hunter for its reception; but in 1806, the lease of the premises having expired, it was resolved by the Board of Curators to deposit it temporarily in a house in Lincoln's-inn-fields, adjoining the College of Surgeons, the Council having at the same time come to a resolution to erect an appropriate building for its reception, and to apply to Parliament for assistance in accomplishing the work. Plans were accordingly drawn up, and the expenses of the undertaking were estimated at 15,000/. This sum was liberally granted by Parliament, and the building was commenced in the course of the following summer. The work does not, however, appear to have proceeded "very rapidly; the real cost of the structure, it was found, would be treble that of the estimated expense; and a second application to the legislature was resolved on. This elicited a second grant of 12,500/., and the remaining deficiency (equal in amount to the sums voted by Parliament,) was made up out of the funds of the College. At length, in the year 1813, the edifice being completed, and the necessary arrangements made, the museum was opened to the inspection of visitors.* In the year 1806, in compliance with the conditions of agreement under which the Hunterian museum was entrusted to the College of Surgeons by Parliament, the Council took the necessary steps for instituting two annual courses of lectures, the one on surgery, the other on anatomy. These were delivered for the first time in the spring of the following year, and have been continued annually ever since. The number of lectures in each course amounted to

* During the time that the museum continued in Castle-street, it was open, under certain limitations, to the inspection of the public, and during the short peace was visited by many eminent scientific foreigners; amono-stwhom were MM. Du Fresne, Parmentier, Abbe Gregoire, Jean Baptiste Huzard, Dr. Gartner, Dr. Sioll, Professor Aldini, and Dr. Frank. The first of these gentlemen was highly delighted, and expressed his satisfaction in a paper in the first volume of the Annates du Museum. In 1813 Cuvier visited England, and for the first time saw the Hunterian museum, to which he paid the greatest attention, and had thirty or forty drawings made of different preparations by a gentleman who accompanied him. THE LIFE OF JOHN HUNTER. 103 fifteen; and as the chief object aimed at in their institution was the elucidation of various parts of the museum, it has been customary to select from thence most of the preparations introduced by the Professors in illustration of their doctrines. In 1813 Dr. Baillie and Sir Everard Home, the trustees of Mr. Hunter, provided for the delivery of an annual oration on his birthday. By this an opportunity has been yearly afforded of paying a tribute of respect-to the memory of those practitioners of surgery who have contributed during their lives to the advancement of our profession.* , To these lectures all the Members of the College have of course a right of entry; and the senior pupils attending the London Hospitals are by courtesy allowed to be present. From the time when the museum first became the property of the College up to the present day, valuable additions have been continually made to its contents. These have accrued chiefly from two sources: on the one hand, from the purchase of appropriate objects contained in other collections, as the British Museum, the Leverian Museum, and the collection of the late Mr. Brookes; on the other, and this has proved by far the most copious source, from the liberal donations of public bodies and private individuals, amongst which those presented by some of the leading members of the Council hold a conspicuous place. Many, valuable preparations have also been added by the diligence of the Conservator and of the Assistant-Conservator. The additions from these and other sources amount at present to nearly one third of the whole collection. It is intended in the present chapter to give some account of the contents of this noble monument of the genius of Hunter; a work which stands unrivalled in its kind,f and the contemplation of which must ever call forth the highest respect for the indefatigable industry and extraordinary talents of its founder. The original design of Hunter, in the formation of his museum,

* It may be worthy of consideration whether it would not be better that these orations should occur less frequently. It is a hopeless task to seek for something new every year on so limited a subject. Mr. Lawrence's late able oration might seem to contradict this remark; but it will be observed that he wisely quitted the accustomed track, and sought for interesting matter in other countries and in the collateral field of natural history. f This opinion is not only that of Englishmen, who have had an opportunity of comparing the admirable manner in which the preparations are displayed in the Hunterian museum with that of some of the most famous on the Continent, and, amongst others, of the Jardin des Plantes, but of foreigners also. Soon after the conclusion of the late war, the Emperor of Russia sent a body of scientific men to make the tour of Europe in pursuit of science. Those who came to England had previously visited the collections on the Continent. Their patience was inexhaustible ; and of the many individuals who have visited the Hunterian museum, none ever examined it with so much care, or brought a larger share of previous information to the work, than they did. When they had concluded their inquiries, they unhesitatingly declared that this collection far excelled any other in Europe. 104 THE LIFE OF JOHN HUNTER. was to furnish an ample illustration of the phenomena of life exhibited throughout the vast chain of organized beings, by a display ot the various structures in which the functions of life are carried on. His collection, therefore, at its commencement, was strictly physiological in its character; and though in the course of time various other departments were added to the original one, they were all in a manner subservient to this primary design. Amongst these accessory departments we may mention, first, the collections of dried preparations in comparative anatomy, and the collection of comparative osteology, as being both nearly allied to the subject of general physiology' Next to these may be placed the collection of monsters and malformations, which is not less so. To the subject which the latter is designed to illustrate much attention has of late years been deservedly directed, since the study of abnormal productions not only leads to a knowledge of the fact that nature is subjected to certain laws, even in her most striking deviations from the usual order of things, but also helps to throw much light on the laws of normal or natural formation. In addition to the above, the museum contains a large collection of specimens in natural history, of which the greater number are preserved in spirits, and others are stuffed ; whilst those animals, or parts of animals, which require no such preparation, as shells, zoophytes, and insects, form separate departments. Nor did Hunter confine his attention to the animal forms now in existence, but, not long before his death, collected a large number of valuable fossils, illustrating the structure and form of animals of a former age. Another highly valuable portion of the museum illustrates the actions of living parls when in a state of disease. This portion contains two large collections of pathological preparations, the one containing specimens of diseased parts preserved in spirits, the other specimens in a dry state ; and a collection of the inorganic products of diseased action, as calculi, concretions, &c. A numerous assortment of valuable drawings, oil paintings, and casts, completes the whole; of these the former are the most valuable, since, from the excellent style in which most of them are executed, an accurate notion is afforded of the recent appearance of parts, when this has been destroyed in the original subjects, either by time or by the action of the spirits in which they are preserved. In describing more in detail the various parts of the museum, each department will be successively treated of in the order in which they have been mentioned above. Before proceeding, how- ' ever, to this description, it will be requisite to say a few 'words respecting the work on which Hunter was engaged at the time of his death, and which he designed as an exposition of the contents of his museum ; and also to make some remarks on the formation of the Catalogues which are now in the course of publication by the Council of the College of Surgeons, and from which the summary I am about to give will be principally derived. It would seem that for many years Hunter was accustomed to THE LIFE OF JOHN HUNTER. JQ5 trust chiefly to his own memory for a history of the specimens contained in his museum; but when his health and faculties began to fail, under repeated attacks of disease, he became exceedingly anxious to complete the arrangement of its various parts, and to commit to writing an exposition of the whole. The reflection that he should probably die before this labour was completed, and leave his collection, the sole provision he had made for his family, in a condition which would greatly detract from its value, was a source of painful anxiety during the last years of his life. It would appear to have been Hunter's intention, had he lived, not simply to form a catalogue of the numerous preparations contained in his museum, but to record, in one comprehensive work, the results of his labours and observations in each department, together with such general reflections a's he had been able to deduce from them. In this work would have been included the anatomy of the whole animal kingdom, as far as he had investigated it, and there is sufficient evidence that few forms of animated nature had escaped his notice. He would have stated at large his views on the nature of animal life, on the particular uses of the several organs, and on their relations to one another. The laws of abnormal formations, as far as he was acquainted with them, would also have been unfolded; and from these various data would have been deduced a classification of animals according to their natural affinities. The fossil remains of past ages had also occupied much of his attention, and his opinions respecting them would have filled an important place in his purposed work. It was his intention also to have entered into a full account of the several sections of his museum which are more directly connected with the practice of surgery, those, namely, which contain the pathological preparations ; and it must ever be regretted that we have been deprived of his exposition of these departments, in which would have been combined enlarged and scientific views of the nature of disease, with the sound practical information which his great experience and acute observation would no doubt have furnished. Such was the work in which Hunter designed to embody the knowledge acquired during five-and-forty years spent in the diligent investigation of nature; and let it not be thought that the above sketch figures forth an undertaking which it would have been beyond the power of any single man to complete; an immense body of materials had already been prepared for different parts of it, and the regularity and rapidity with which he pursued his labours would almost certainly have insured its completion within a few years. Had he completed it, " this work," to use the language of one who has had ample means of knowing what were the intentions of Hunter, and of estimating the extent of his labours,* " would have reflected equal honour on its author and on the country and age in which he flourished." * Mr. Owen. 11* 106 THE LIFE OF JOHN HUNTER. Hunter died, however, before this his last undertaking could be completed, but not before enough had been accomplished to furnish us with means from which to form some judgment of what the whole would have been. Of his labours in the field of comparative anatomy, which for variety and extent have probably never been excelled, he kept accurate and full minutes. These alone extended to ten folio volumes of MSS. ;* and besides these there were catalogues of certain portions of the' physiological department, with interesting general observations of his own prefixed to each series. To the account of the pathological preparations of the bones, Hunter had also devoted especial attention, as he proposed (according to the late Mr. Cline), to publish a work on the diseases of these parts, and had collected an immense number of drawings in pursuance of this intention. The whole of the above valuable documents passed into the hands of the College along with the preparations to which they referred; and it was the intention of the Council, with the aid which they afforded, to have prepared a descriptive catalogue of the whole museum. Before this work was far advanced, however, the ten volumes of minutes of dissections, along with many other valuable papers, were taken from the museum by Sir Everard Home,f without any previous permission from the Trustees, but with the alleged intention ef employing them in preparing a catalogue, which he undertook to do gratuitously. Time, however, passed on, and no catalogue was forthcoming; repeated applications were made by the Council to have the MSS. restored, but were as often evaded, and at length, to the astonishment of all, it was ascertained that Sir Everard Home had actually committed them to the flames ! The announcement of such a proceeding of course drew upon him the bitter reproaches of the Trustees and of the Council, against which he defended himself by maintaining his legal right to the papers, which he asserted formed no part of the museum, as no mention was made of them in Hunter's will; and he added further, that in burning the papers he had acted in accordance with the directions of his late brother-in-law. The first of these statements it was of course not worth while legally to contest, seeing that the objects in dispute were now no longer in existence. To^give credence to the latter was somewhat difficult for those who knew how high a value Hunter had set on these papers. To such it seemed

* Nine of these were on animal, and one on vegetable anatomy. They were written by Mr. Hunter's assistants, at his dictation, and contained the result of his observations upon whatever was new and interesting in the course of his individual dissections. It may be looked upon as a proof of the value which Hunter set on these, that he had them introduced into his portrait by Sir Joshua Reynolds. His cases of surgery and dissections, of which the College possesses four or five manuscript volumes, presented by Sir Everard Home, were recorded with equal accuracy. f This was in 1812, when the collection was placed in the new building. THE LIFE OF JOHN HUNTER. 107 incredible that he should have ever seriously meditated the sacrifice of these memorials of the labours of his life ; and it was justly urged, that if he had ever, in a moment of irritation, given expression to such a wish, Sir Everard Home should have felt that he would not only be justified in neglecting to fulfil it, but was bound to do so, for the honour of his patron and preceptor, and for the interests of science. Was it not also somewhat strange, it was asked, if such a direction was given, that Sir Everard Home should have neglected to execute it during the time the papers remained in his hands previously to the purchase of the collection by Parliament, and should have delayed its accomplishment until every one else supposed that these documents had, to all intents and purposes, become the property of the College ? Rumour, as usual, assigned reasons for this act beyond the one alleged, and it was broadly asserted, that if the MSS. could be recovered, they would be found to have furnished the substance of many of Sir Everard Home's numerous papers in the Philosophical Transactions.* Whatever may have been the cause of this extraordinary proceeding, the effects are irreparable. The difficulties experienced in the formation of a catalogue were so much increased by the loss of these papers, that those whose duty it was to superintend the work seem thenceforward to have despaired of ever carrying it into effect. At least such is the conclusion we must come to, when we recollect that nearly thirty years were allowed to elapse from the time the museum became" the property of the College before the Council took effectual steps to supply such a catalogue. Whether this state of hopeless inactivity was excusable may well be doubted, when we see how satisfactorily the work will, in all likelihood, be completed, now that it has been resolutely undertaken. For though there can be no doubt that the establishment of the Zoological Society, and the liberal manner in which they have granted the bodies of the animals dyinov in their collection for the use of the College, have greatly facilitated the execution of some parts of the catalogue, it will yet scarcely be credited that the Council, had ihey been in earnest/could not have found individuals long ago willing to undertake the task, and able to have executed it, if not as well as it will now be executed, yet in a manner which would have greatly increased the value of the collection to the profession at large. As it is, they will hardly free themselves from the imputation of want of zeal in discharge of their trust, and of having shown a culpable indifference to the honour of their great master and to the cause of science in this country. Happily, the Council were at length induced to take active measures for supplying the deficiency so long and justly complained of, and two gentlemen were appointed to assist the conservator, Mr. Clift, in preparing complete catalogues of the museum. These

* Sir Everard Home contributed more papers to the Royal Society than any other single Member of that distinguished Body since its foundation. * 108 THE LIFE OF JOHN HUNTER. were the late Mr. Home Clift, the son of the conservator, and Mr. Richard Owen,* who is well known as one of the first comparative anatomists in this country. Certain departments were allotted to each of these gentlemen, of which they were directed to draw out catalogues as speedily as might be consistent with correctness. The first of these was published in 1830, since which time five more numbers of the general catalogue, and two numbers of a descriptive catalogue, on a more extended scale, have appeared. It is understood that we are indebted to the respected conservator, Mr. Clift, for the first and second parts of the general catalogue, containing an account of the pathological preparations in spirit and in a dry state. To Mr. Home Clift, his son, whose untimely death was lamented by all who knew him, we owe the third, fifth, and sixth parts, containing catalogues of the human and comparative osteology, of monsters and malformations, and of the vascular and miscellaneous preparations in a dried state. To Mr. Owen was allotted the task of preparing the fourth part of the general catalogue, which furnishes an account of the preparations of natural history in spirit, and^the still more important and difficult duty of forming a descriptive catalogue of the first two divisions of the physiological gallery. The whole work, as far as it has* yet appeared, reflects credit on the Council, under whose auspices it has been published, and by whom the above appointments were made, and on the gentlemen to whom the business of preparing the catalogues was intrusted, for the talent displayed in the performance of the several parts. It is, however, to be regretted that a fuller account of the pathological preparations was not given, since the want of a history of the cases often deprives them of more than half their value. It is understood, however, that the Council have it in contemplation to publish descriptive catalogues of the whole museum, which will probably extend to twenty volumes, and no doubt the present deficiency will then be amply supplied-! With regard to that portion of* the descriptive catalogue which is already before the world, too much praise cannot be given to Mr. Owen for the very able manner in which he has performed the difficult task of preparing it. When it is recollected that a great many of the preparations in this department had not even a tittle attached to them, and afforded no clue beyond their situation in the collection, and their general appearance, for ascertaining what they really were or whence derived, and consequently that a search was to be instituted for their likeness in the great book of nature, it will be readily granted that no little talent and diligence were required in overcoming this first difficulty. But, in addition to this, the object which Hunter had chiefly in view,

* Mr. Owen was appointed in 1827. | The conservator has long been engaged in the preparation of such a catalogue, which at the present time extends to five times the length of that published by the Council. The urgency of the demand for a catalogue on the part of the public and the Board of Trustees, was the only reason why the Council confined themselves to the fulfilment of their literal engagements. THE LIFE OF JOHN HUNTER. 109 in the formation of several of the series, was to be sought amongst his various publications, or, where these did not furnish the requisite information, to be deduced from the writings of others, or from the observations of Mr. Owen himself; and from each of these sources have been drawn the valuable observations prefixed to several of the subdivisions. That Mr. Owen has been successful in overcoming these difficulties, the catalogue itself affords sufficient evidence, and the students of natural science will owe him a debt of gratitude should he succeed in that portion of his work which is yet unfinished as ably as he has done in the part which has already been published. , Having thus given a general account of the museum up to the formation of the catalogues, I shall now endeavour to furnish as accurate an account of its contents as the means in my power and the nature of the present work will admit. The first and fundamental department of the museum, that, namely, which is contained in the gallery of the present building, is, as has been said, devoted to the illustration of the science ot life itself. . . , '• It consists of dissections of plants and animals, in which the structures subservient to the different functions are skilfully and intelligibly displayed. . " These structures are taken from every class of organized matter, and are arranged in series, according to the function, in the order of their complexity, beginning with the simplest form, and exhibiting the successive gradations of organization to the most complex. " The series are disposed in two divisions : first, those illustrative of the functions which minister to the necessities of the individual ; and secondly, those which provide for the continuance of the species. " The first division commences, with a few examples of the component structures of organic bodies, and then extends into a series embracing the active and passive apparatus for progressive motion. It is succeeded by analogous series, illustrative of the functions of digestion, nutrition, circulation, respiration, and excretion,—or the functions immediately connected with the internal economy of an organic being. Then follow the organs which bring the animal into relation with the external world, viz. the nervous system and organs of sense, which are the peculiar characteristics of the animal kingdom. After these come the parts which complete the system of an animal body, such as the connecting and adipose tissues, and the various modifications of external covering; and lastly, those instruments which, not being immediately related to any of the vital and animal functions, constitute peculiarities in the economy of particular species. The second division commences with a series ot the generative organs of plants and animals in the passive and unimpregnated state: first, of such as complete the function of generation by the 110 THE LIFE OF JOHN HUNTER.

simplest kind of hermaphroditism; second, of those in which a necessity for reciprocal impregnation co-exists with the possession of both the sexual systems in the same body; and lastly, of the male and female organs, as they are exhibited separately in distinct individuals. " The next subdivision contains the female organs in a state of fructification or impregnation ; it exhibits the generated organism in its different stages towards mature development, together with the various temporary structures destined for its support during foetal existence; and lastly, the organs in the parent which supply the young with food, or afford it shelter during the helpless period of its existence."* Such is a brief summary of the contents of this part of the museum which consists of 3745 anatomical specimens, of great delicacy and beauty, and for the most part in an'admirable state of preservation.

FIRST DIVISION OF THE GALLERY,

ILLUSTRATIVE OF THE FUNCTIONS WHICH MINISTER TO THE NECESSITIES OF THE INDIVIDUAL.

That portion of the descriptive catalogue which has been published furnishes an account of 841 of these preparations, which form the two first subdivisions of the first division, and are designed to illustrate the functions of locomotion and digestion.

ILLUSTRATES THE SUBJECT OF LOCOMOTION.

To the elucidation of this subject thirteen series are devoted, of which the first exhibits the component parts of vegetables and animals, as barkj wood, blood, tendon, elastic ligament, cartilage, bone, &c, &c. To tljese succeed examples of different kinds of sap and blood, the former arranged according to their degree of vitality, as shown by their tendency to coagulate: from these we ascend to the colourless blood of crustaceous animals, the cold blood of reptiles and fishes, and lastly, the warm blood of the mammalia. With the third series, we enter on those parts of vegetables and animals which possess evident motion. Motion in vegetables Hunter considered to depend on a property analogous to irritability in animals : it may be caused either by the irritability being excited, as in the mimosa and other sensitive plants; or by the cessation of * Introduction to the Descriptive and Illustrated Catalogue of gical Series: 1833. By Mr. Owen. THE LIFE OF JOHN HUNTER. Ill irritation allowing an antagonist force to take effect, as in the sleep of plants. The fourth series contains preparations of the muscular fibre, which, says Hunter, " is one of the simplest forms of an active solid." The various modes in which these fibres are arranged in various muscles are shown; and to these succeed several preparations illustrative of the application of muscles, and the manner in which certain parts of the body, as we ascend in the scale of animals, come to be specially devoted to the production of motion, either actively, as in the case of muscles, or passively, as in that of the skin of worms and of the larvae of insects; of the hard covering of crustaceous animals; of this combined with an internal skeleton in the testudines; or of the latter alone in fishes, birds, and mammalia. The application of elastic powers in the animal frame is next illustrated. These act either in opposition to muscular force, as in the hinge of bivalves, or in aid of it, as in the ligamentum nuchas of various mammalia. The five succeeding series illustrate the particular properties of the organs of passive motion. These organs, as is here shown, may be formed either of membrane, horn, cartilage, calcareous earth, or of various combinations of these. The growfh and composition of shells are next illustrated, for though shells for the most part serve as organs of defence, " they are in many cases used as levers for the muscles to act on." Most of the preparations illustrating this subject have been added of late years, and the varieties they exhibit in chemical composition, &c, are explained in the Catalogue, by extracts from Mr. Hatchett's papers on the composition of bone and shells. The structure and growth of bone is next unfolded. The differences which bones exhibit in consistence and composition in different classes of animals, the mode in which ossification commences, and the superior vascularity of growing bone, are amply developed. Next follow twenty-four preparations, exhibiting the growth, perfection, and casting of the horns of deer. And lastly, the increase of size in bones is shown to take place, not by the insertion of new particles amongst the old, as Duhamel supposed, but by the addition of new parts to the extremities and circumference of bones, whilst the form of the bone is preserved by the removal of superabundant parts by the absorbents. The former fact is shown by preparations of the leg-bones of fowls, into which shot had been inserted at given distances from each other whilst the bones were growing, which distances were found not to have varied when the bones had much increased in length. A fuller illustration of both facts is afforded by feeding young animals on madder, which tinges all fresh deposits of bone, and thus points out exactly where and to what extent these have been laid down. There are several preparations which originally exhibited these points very clearly, but as the spirit has destroyed the colour, the assistance of Mr. Bell's drawings is required for their explana- 112 THE LIFE OF JOHN HUNTER. tion, and engravings of these have been accordingly given in the Catalogue. After the growth of bone, are displayed the various positions of the skeleton in various animals; and the last of the five series illustrates the composition of the skeleton. This may be formed of one piece, as in the cuttle-fish; of several unattached pieces, as in the pennatula and other zoophytes ; or the several pieces may be connected by elastic joints, as in the spine of cartilaginous fishes; by ligamentous fibres attached to the whole articulating surface, as in the lower jaw of the whale; by capsular ligaments; by capsular and inter-articular ligaments, as in the hipjoint or with inter-articular cartilages, as in the joint of the lower jaw; or by the three combined, as in the human knee-joint. The various mechanical contrivances by which the power of muscles is augmented, so as to combine neatness, which, as Hunter observes, " is often a principal object in the formation of a limb," with the requisite degree of power, form the twelfth series. The thirteenth and last series of this subdivision shows the form and arrangement of parts in the various organs adapted for progressive motion; for swimming; for flying; for creeping, as serpents, in which animals the progressive motion is effected by means of the ribs, which have strong muscles attached, and are moved much in the same way as the centipede moves its legs; for burrowing ; for climbing; for leaping; for walking or running; and lastly, for tearing the prey of the animal. THE SECOND SUBDIVISION

ILLUSTRATES THE FUNCTION OF DIGESTION.

Teeth.—Of the organs which minister to this function the teeth are first treated of. The series in which the nature and offices of these organs are shown consists of 170 preparations, derived from all parts of the animal kingdom, the account of which in the Catalogue is preceded by some general observations by Mr. Hunter on their nature; on their analogy to the beaks of birds ; and on the varieties they exhibit in number, form, structure, and situation, according to the food of the animal; as also on the mode of their formation and growth ; on the manner in which the place of those which are lost is supplied ; and on their relation to the stomach. These several points are illustrated in a number of subseries, of which the three first exhibit the structure and growth of parts analogous to teeth in various tribes of animals, as the calcareous teeth of some mollusca, the bills of birds, and the whalebone in whales. The fourth subseries exhibits the mode of growth of various teeth. 1st, Of such as are limited in their growth and which, when lost, require to have their places supplied by'new teeth; and this is effected in a variety of ways. 2d Of such as are continuous in their growth, as the incisors of rodentia and the THE LIFE OF JOHN HUNTER. H3 tusks of boars. The amount of animal matter contained in various descriptions of teeth is shown in a set of preparations, in which the calcareous part has been removed by the use of dilute acids. The mariner in which the teeth are shed, and their places supplied by new ones, in different orders of animals, is next shown. In some the teeth are shed but once, and those of the new set are formed on distinct pulps, as in most mammalia; in others, as in the shark, teeth are successively formed at the back part of the mouth, and brought forward by the absorption of the fore part of the jaw. In the crocodile there is a constant succession of new teeth, which are formed on the same conical projecting pulp which the former occupied: in many kinds of fish the new ones are formed in rows of distinct pulps, and these may be situated either within or without the rows in use, but in either case are brought into action by the absorption of the opposite side of the jaw. The last subseries displays the varieties in the situation of the teeth, which may be placed either on the jaws, the tongue, the palate, or in the stomach. We next come to the principal organ of digestion. Stomach.—This organ Hunter considers to be the essential part of every animal. In its simplest form it is a mere bag, secreting a liquid capable of dissolving and animalizing its contents, and possessing the power of absorbing the nutritious parts of the food, and rejecting that which is indigestible. In many cases such a bag constitutes the'whole animal, as in the hydatid; but in most animals other parts are superadded to assist in the process of digestion. These parts vary exceedingly in different tribes, and "would serve as a ground for the classification of them." A copious illustration of the above facts is furnished by a number of preparations selected from the various orders of animals, commencing with the most simple, in which the stomach has but one orifice for the reception aqd rejection of foreign matter; and ascending through the radiated animals, where two orifices are found, and the digestive cavity is divided into stomach and intestines; to the insect tribe, where, in addition, a crop is sometimes found, for retaining the food previously to its undergoing digestion; or, in the case of the bee, to its being deposited in the hive. To these succeed the stomachs of mollusca, ascending from the ascidians, or soft-shelled mollusks* as Hunter aptly called them, through the acephalous tribe to the gasteropoda and cephalopoda of Cuvier. The stomach of fishes is next displayed, which is for the most part a simple capacious bag, between which and the large and muscular oesophagus there is often scarcely any distinguishable separation. In some fishes, as in the Gillaroo trout and mullet, the

* Hunter had paid great attention to the anatomy of these animals, as also to that of the cirripeds, on both of which Cuvier has also published memoirs. The beautiful engravings attached to this, portion of the Catalogue show how accurately and fully Hunter had unfolded the structure of the various organs, and how eorrectly, for the most part, he had made out their several offices. 12 114 THE LIFE OF JOHN HUNTER. stomach is a strong muscular organ, fitted in the former for breaking the shells of testaceous animals, on which it feeds; and in the latter, to grind down with sand the vegetable substances of which its nutriment consists. In reptiles we find great diversities in the form of the stomach. In the ophidians, both this and the oesophagus are capable of great distension, for the reception of bulky animals, on which they prey. In the chelonians it is broad and flat, like the body; whilst in the crocodile it is divided into two cavities, a cardiac and a pyloric, much as we find it in some of the carnivorous birds. Birds are furnished with a proventriculus, or glandular cavity. which receives the food before it passes into the stomach, or gizzard ; and in the crane tribe we find a pyloric cavity between the gizzard and duodenum, as in the crocodile. The gizzard varies much in the strength of its muscular coat: this in carnivorous birds is much weaker than in granivorous ; but if a bird of the former kind be fed on grain, the gizzard will become gradually more developed, as is shown by the preparation of a gull's stomach which had been so fed. To the stomachs of birds succeed those of mammalia. In many of these the stomach consists of a simple cavity, which in the ornithorhynchus takes the general form of a gizzard, the cardiac and pyloric orifices being close to each other, as in birds. In the porcupine, the stomach is partially divided into three cavities; in the peccary the division becomes more complete, the oesophagus opening into the middle one, whilst the cavity of the fundus takes a bifurcated form. In ruminating animals, however, a still greater degree of complexity exists: in these we find four cavities, the first two of which receive the food prior to rumination; but after rumination the food is prevented by a peculiar sensibility of the sphincter, which closes their orifices, from re-entering them, and is passed on by a sort of canal to the psalterium, or third'cavity, and from thence to the abomasus, or fourth cavitv. In the llama and camel the muscular fibres of the first two cavities are disposed relicularly, and the mucous membrane forms saccuh between the meshes: into the sacculi of the second cavity water is received and is preserved there for a long time in a pure state. In the whale tribe we find the stomach assuming a loculated form and consisting of from four to seven cells, disposed in a row one after the other. In this series are also deposited several preparations illustrative of the d.gest.on of the coats of the stomach after death; a fact which Hunter first pointed out and explained Intestines.-The: Third Series displays the structure of the intestines in various tribes of animals, arranged in the same order as is adopted for the stomachs. Glands.-The Fourth Series exhibits the varieties which exist in

digest." C°mp0Sltl0n °f the Slands which ^d in the process of THE LIFE OF JOHN HUNTER. 115 First, of the salivary glands: these in many mollusks are found in the form of tubes, blind at one end, and opening by the other into the buccal cavity, or oesophagus, and gradually as we rise in the scale assume the form of conglomerate glands. Next, of the pancreas; which in like manner is first seen under the form of caecal tubes, opening into the upper part of the intestine. ' The same may be said of the liver at its first appearance as a separate organ. It soon, however, as in the mollusks, assumes the form of a conglomerate gland, and is in these of a large size. In the lower animals the bile is secreted from arterial blood. After the liver, the gall bladder and ducts are exhibited. In many of the lower animals, and in some of the higher, there is no gall bladder. In the squalus maximus, for example, twelve ducts convey the bile from the huge liver to a receptacle six feet distant, and lying in contact wilh the duodenum, into which it opens. This, however, is not supposed to be analogous to the gall bladder, as a similar receptacle is found in the elephant, which possesses a gall bladder. Next follow preparations of the spleen, and other appendages of the alimentary canal, and these complete the division devoted to the function of digestion. Absorption.—The function of absorption is the one which is next illustrated. In vegetables this function is shown to be performed by simple tubes commencing in the roots, of an equal diameter throughout, and without branches. The first traces of the absorbent system in the animal tribes are found in certain of the medusas, as the rhysostome, on which vessels are found opening on the fringe, like appendages of the stem. These take up nourishment from the water, and coalescing into larger trunks, empty their contents into the digestive cavity. In the aphrodita the absorbents consist of small capillary vessels, arising from the caecal appendages of the intestine, where they take up the chyle, and convey it to various parts of the body, without the intervention of a heart. The next step is to the lacteals of the higher animals, which terminate in the venous system. But the absorbents are employed not only in taking up nutriment for the supply of the body, but in conveying away the effete particles; and these are termed excretory absorbents. Amongst preparations illustrative of this function is one on which Mr. Hunter set a high value, as affording demonstrative evidence that the absorbents perform the above office. This is a preparation from the head of a spermaceti whale, where the lymphatics are seen filled with this animal oil, which they were in the act of taking up. Circulation.—The organs of the circulation are next exhibited, in an ascending order. First, in those animals in which there appears to be no heart, as the leech, where we find two sinuous ventral vessels and a small dorsal vessel, each giving off lateral branches. In the amphinome, which has external branchiae on each ring, small 116 THE LIFE OF JOHN HUNTER. vessels convcv the aerated blood from them to the dorsal artery: this gives off other branches, and. amongst others, one which courses along the upper side of the intestine, whilst the corresponding vein to which ils branches pass runs along the under side, and with the other veins enters the ventral vessel,Yrom whence lateral branches are sent off to the branchiae. The situation of the heart in different animals is next shown. This, as Hunter observed, depends on the situation of the organs of respiration, which it always follows. In insects the heart is a long tube, placed in the back, and extending from head to tail. In the lobster and other crustaceae it consists of a single cavity, also seated in the back, and of about the same extent as the roots of the branchiae. In bivalve mollusks it is seated in the centre of the back. In the gasteropods, in various parts of the body, following the branchia\ In fishes, just at the lower angle of the gills, vfcc. Its composition becomes more complicated as we ascend in the scale of organization, beginning with the dorsal vessel of insects, which receives the blood through valvular openings in the sides of the vessel, from the irregular venous sinuses which permeate the adipose tissue, and distributes it to the body through lateral branches, as shown in the injected preparation of a large caterpillar. In the ascidians, or soft-shelled mollusks, there is a single long ventricle,' which receives the blood at one extremity and distributes it from the other end to the branchial sac and body. In bivalves we find a single ventricle, sending the blood to the branchiae, from which it passes to the body, and is received back into two auricles, which supply the ventricle. In the snail we have one ventricle and one auricle. In the cuttle-fish we find both a systemic and a branchial ventricle, and the latter indeed is divided into two portions, one seated at the base of each of the branchiae. Two auricles receive the blood from the branchiae, and empty themselves into the systemic ventricle. In fishes we find a branchial ventricle and a single auricle. In some of the cartilaginous fishes the heart is largely supplied with valves ; in the lophius europaeus, for instance, the veins opening into the auricle are seen to be guarded by valves: the auriculoventricular opening has semilunar valves, and the openino- from the ventricle into the bulb at the root of the main arteryls surrounded with valves. In the sturgeon there are no less than three rows of valves in the bulb. In reptiles we find two auricles, one receiving blood from the lungs, the other from the body, and a single ventricle supplying both. The ventricle, which in frogs and other batrachians is a simple cavity with one aorta, in the ophidians/chelonians, and saurians becomes more and more divided into different cells by imperfect septa, the general effect of which is to prevent the aerated blood from mixing equally with the whole mass of circulation- fluid and to direct it rather towards certain parts, as the head°and upper extremities. vv THE LIFE OF JOHN HUNTER. 117 In birds we attain the most perfect form of heart, consisting of two ventricles and two auricles, as exhibited in the hearts of the ostrich, emu, &c. The same form of heart prevails in mammalia; and under this head we find preparations of the huge heart of the elephant with its three venae cavae, and of the far more enormous heart of the whale. To the foregoing preparations succeed others, in which the structure of the blood-vessels is exhibited : the nature and form of their valves; the several coats of which they consist; and the varieties in these displayed in .different animals. The outer of these coats may be deficient when the vessel passes through cartilage, as is shown in the cervical vertebrae of the squalus maximus. Respiration.—The organs in which the aeration of the blood is effected are exhibited in the succeeding series. This process may be effected, First,—by exposure to the air contained in water. The simplest form of the organ is where a certain portion of the general mass is especially devoted to this object, as the thin edge of the disk in some kinds of medusae. In some of the annulose animals, as the amphinome, the organ consists of a bunch of rays seated on either side of each ring. In others, as the amphitrite, the branchiae are collected on the rings of the neck. In the lobster and other crustaceae, the branchiae are attached to the legs, and are covered by a lateral extension of the dorsal shell. In bivalves they form foliated appendages on either side of the body, between it and the mantle. In the gasteropod and other mollusks the branchiae assume very various and often elegant forms, and are variously placed on the body. In the myxena, lamprey, and other cartilaginous fishes, the gills consist of a row of saccoli, varying in number, and placed on either side of the neck, each sac having an external orifice and an opening into the oesophagus, and its internal membrane being variously laminated, to afford larger surface for the aeration of the blood. In the bony fishes the gills are supported on bony arches, and covered by an operculum ; these arches differ in form, and in some instances assume a very elegant appearance, as shown in preparations of the branchiostegal bones from the devil fish of the Antilles and others, Secondly,—-For the exposure of the blood to the air in water, and to the atmosphere. The foetus of the squalus alopeceus is shown to be furnished with external branchiae when first born, as well as with gills; the former drop off after a time. \n the siren and proteus there are external branchiae and lungs, and both are persistent. Thirdly,—-For the exposure of the blood to the atmosphere. Amongst the reptile tribes, we find that snakes are furnished with a single lung, consisting of a long bag, the upper part of which has vesicular parietes, whilst the lower serves as a reservoir of air, to be employed during the time in which the animal is swallowing its 12* 118 THE LIFE OF JOHN HUNTER. prey and its trachea is obstructed. In frogs the lungs appear like a conglomeration of transparent sacculi. In the turtle these sacculi are much smaller, and more numerous, so as to give the lungs more the appearance of those of the mammalia, which are last shown. The series is completed by twenty preparations of the tracheae and organs of voice in birds and mammalia. Kidneys.—The organs for the depuration of the blood, or the kidneys, are next exhibited, and some of their most remarkable differences in situation, number, form, and structure in the vertebrated animals are shown. Brain.—To this succeeds a series, containing about ninety preparations, in which the development of the brain and spinal marrow, from the knotted cord of insects and Crustacea, with a small ganglion above the oesophagus ; representing the brain upwards through fishes, reptiles, and birds, to the perfect brain and spinal cord of the mammalia. This series is perhaps one of the least complete, and this has arisen from the small degree of importance which these organs obtained in Hunter's physiology compared with that attached to them in the present day.

To the series illustrative of the central portions of the nervous system succeeds one consisting of not less than four hundred preparations of the several organs of the senses. Of Feeling and Touch,—Exhibiting the cutis increasing in vascularity in proportion as its sensibility increases ; the varieties in compactness, density, &c, which the cutis exhibits in different animals ; the slowness with which it decays under certain circumstances, as illustrated by a preparation of the right hand of a body, said to be that of John of Gaunt, in which the cutis is perfect; lastly, its retention of marks made in it, as in the tattooed skins of South-Sea Islanders or British sailors. Of Taste.—Exhibiting the tongues of animals, arranged according to their secondary uses ; to which succeed fifteen preparations of some of the principal varieties of the mouths and fauces of different animals. Of Smell.—-In fishes the organ of smell assumes the form of laminae, arranged in various order around the nasal cavity In reptiles the cavity is divided by folds of the olfactory membrane, as in the higher animals; but these do not contain bonv plates between their layers : the organ is exhibited in the turtle and other animals of this class. In birds the extension of the nasal cavity becomes greater, especially in birds of prey, and canals leading from it communicate with the air-cells of the head, as shown in the swan and eagle. In mammalia it becomes still more complicated. Of Hearing-In this collection are contained several good preparations of the ear in fishes, to which Hunter had paid much at- THE LIFE OF JOHN HUNTER. 119 tion, showing the semicircular canals, the sac in which they terminate, and its ossicles, varying in number from one to three. In most fishes the ear has no external communication ; but in the ray, the squalus, and other cartilaginous fishes, a canal leads from the sac to the surface of the head, where its orifice is closed by a membrane. In reptiles, birds, and mammalia the organ becomes gradually more complicated by the development of the concha and addition of the tympanum and external ear. Of Sight.—The structure of the eye and its appendages is developed in a hundred and fifty preparations. The peculiarity in the eye of the cuttle, which Cuvier has since pointed out, namely, that the choroid coat is placed in front of the retina, had attracted Hunter's notice, and is shown in several preparations. The structure of the eye in fishes, fitting them for seeing in a medium of high refractive power, is shown ; as also the peculiar fulcrum on which the eye revolves in cartilaginous fishes. The plicated arrangement of the retina in birds, enabling them to see at vast distances; the tapetum lucidum, the membrana nictitans, and the various forms of the pupil in several mammalia, adapted to their habits of life; and lastly, the structure of the eye in man, are all exhibited in this series. Cellular Tissue.—To the organs of the senses succeeds a series in which the various forms which the cellular tissue assumes are well shown, as also the varieties of oil and fatty matter contained within its cells in different animals. External Coverings.—The external covering alone remains to complete the list of parts fitted for providing for the necessities of the individual, and the various forms which this assumes constitute the subject of the next series. We commence as usual with the vegetable tribes, of which the texture and appearance of the cuticle is first shown, and next of the animal tribes. The colour of the skin in the latter is seen to depend on the rete mucosum, and this in the dark varieties of mankind assumes more of a membranous character, than in the lighter varieties. The arrangement of the external covering, in the form of hair, bristles, feathers, &c, is exhibited, and the mode in which the latter are formed is developed in several excellent preparations. Several other specimens exhibit the cuticular lining of the oesophagus and stomach in various animals. In others the external cuticle is shown to become thicker where parts are exposed much to the action of external bodies, or to assume the form of scales, nails, hoofs, and spines, or of beaks, horns, or spurs, according as defensive or offensive weapons may be required. Individual Peculiarities.—This division of the Museum is completed by a series of about one hundred and eighty preparations of some of the most distinguishing peculiarities of individual species or of classes of animals in the vegetable and animal kingdoms. Amongst the former may be noticed the elegant natural ewer of the pitcher plant, and the apparatus at the joints of the leaflets, subpe- 120 THE LIFE OF JOHN HUNTER. tioles, and petioles of the sensitive mimosa, causing these parts to collapse on the slightest touch. As examples of the peculiarities amongst animals are exhibited the casting off and regeneration ot the external covering and cuticular lining of the stomach in crustaceous animals; and of the cuticular covering in serpents. Ihe regeneration of entire members in Crustacea, newts, &c. ine green bones of the gar pike, or belone vulgaris ot Cuvier. 1 he dark periosteum of the African fowl. Peculiarities in the intestines arterial system and urinary bladder in various animals. Local deposits of fat for specific purposes. The tentacula of the cuttle tribe, with the suckers which enable them to secure their prey. The termination Of the elephant's proboscis. The substitution of whalebone for teeth in the whale. The ornamental appendages of the male in some species of birds. The peculiar glands of animals whether for internal uses or opening externally, as the oil-bags of birds, the odoriferous glands of the peccary, &c. The air-bladder of fishes. Feet in mammalia adapted for swimming. Fins in fishes for flying. Coralline formations. The stings of insects, and poison-teeth of serpents. The electric organs of the torpedo and electric eel, &c.

THE SECOND DIVISION OF THE GALLERY,

ILLUSTRATIVE OF THE FUSCTION OF RE-PRODUCTION,

Contains about fifteen hundred preparations, admirable alike for their delicacy and beauty as works of art, and for the accurate and extensive information they afford on this interesting department of physiology. They are arranged, according to the Synopsis of the Museum, in ten series. The first series, which contains preparations of the sexual organs in hermaphrodite plants and animals, commences with an elegant selection of subjects, exhibiting some of the most striking varieties in the form and arrangement of these parts in hermaphrodite flowers. To these succeed preparations of the organs in self-impregnating animals, as the asteriae, the cirripeds ; and lastly, of hermaphrodite animals, which perform a double coitus, as the snail, slug, and other gasteropod mollusks. The second series of this division exhibits the form and structure of the male organs, commencing with the stamina of plants; then ascending to the animal kingdom, and exhibiting, first, the testes and penis in insects, as the bee, the scorpion, &c; then in fishes amongst which we find two distinct forms: in osseous fishes the testis, or milt, is a cellular sac, varying greatly in size at different seasons, which opens by a common orifice with the kidney, immediately behind the anus. In the ray and squalus it is a granular mass, having more of the form of the testis in the higher animals, and opens into the cloaca. Several preparations exhibit the testicie THE LIFE OF JOHN HUNTER. 121 in the toad, increasing in size in the season of coupling, and attended with an increase in the size of the tubercle of the thumb, which is emploved in retaining the female. The testis and penis of snakes and lizards are next shown, the latter of which organs is seen to be double. In the crocodile and turtle it is single, and assumes the general form which it exhibits in mammalia; but the urethra, instead of forming a canal, consists of a groove only, in the dorsum penis. In birds the size of the testis varies very much at different seasons; this fact is shown in the sparrow. The urethra is a groove, as it is in reptiles, but the form of the penis varies much. In the ostrich it is straight and large; in the goose, duck, &c, it assumes a spiral form when thrust out from the sheath. The structure of these organs in mammalia, is shown in several injected preparations, and in others where the seminal tubes have been unravelled to show their great length; and the series is completed by several specimens, which exhibit the form and structure of the accessory glands, as the vesiculae seminales, prostate, and Cowper's glands, in different animals. The third series consists of preparations of the female organs in plants and animals. A few specimens of the pistils of plants head • the series ; and these are followed by the ovaries and ducts in molluscous animals; in insects; in fishes, whether bony or cartilaginous ; in reptiles; in birds, where only one ovary is developed ; and in the ornithorhynchus. Next follow the ovaries and uterus in animals, amongst which the latter organ is simple, or divided into two cavities, or furnished with horns. In the marsupial animals the horns are seen opening into a central or third cavity, which does not communicate directly with the vagina, but intermediately, by means of two lateral curved canals. The last eighteen preparations of this series exhibit the form of the clitoris in mammalia, and the occasional appearance of a hymen in them. The coitus in some of the lower animals is exhibited in the ten succeeding preparations. The development of the ovum forms the subject of the three following series. First, in plants which have no evident seeds; next, in gemmiparous animals, as the hydatid ; next, in cryptogamous and phanerogamous plants; and lastly, in hermaphrodite animals, whether self-impregnating, as the asleria, the barnacle; or mutually impregnating, as snails, slugs, and other gasterapods. The sixth series of this division contains about four hundred and fifty preparations, illustrating the various conditions in which the eggs of oviparous animals are placed for the purpose of being hatched, and of the changes which take place in the young animal during the foetal state. The ova of some animals, as certain of the univalve mollusks, are deposited previously enclosed in a membranous nest. In others the eggs are retained in clusters, as is the case with the sepia, the ova of which resemble a bunch of grapes ; or with the roes of osseous fishes. In the insect tribes the young undergo certain metamorphoses before they attain the perfect state : these changes 122 THE LIFE OF JOHN HUNTER. are exemplified in about ninety preparations of the larva and chrysalis state of different insects, and in about the same number, forming a regular series of the changes in the silk-moth. The caterpillar state of several other insects is shown, and these are followed by preparations of the nidus which many insects prepare to receive the egg and contain it during its transformation. The ova of some animals are carried in the arms of the mother until hatched ; in the Crustacea they are fixed to the scales beneath the tail. In osseous fishes they are clustered in masses; in the ray the eggs are deposited singly % each, as it passes through a gandular enlargement of the oviduct, having a horny shell secreted on its surface; this is shown in several very elegant preparations : in the shark the ova are hatched before they leave the oviducts. In Batrachian reptiles the young are furnished with gills, which are cast, off when they leave the tadpole state. Of snakes and lizards, some are seen to have the eggs hatched in the body, and others externally. The turtle and crocodile deposit their eggs on the ground, where they are hatched by the warmth of the sun. In birds they are hatched under the mother. The formation of the egg in birds is next shown; and the series is completed by about forty preparations, exhibiting the progress of incubation in the egg. These, which were originally beautiful preparations, have, from their delicacy, been somewhat injured by time; but happily the deficiency is more than compensated by a series of exquisite drawings, made under Mr. Hunter's eye by Mr. Bell. These will be published along with the descriptive catalogue of this part of the museum ; and if the engravings should be executed, as there is every reason to hope they will be, in a manner worthy of the originals, they cannot fail to excite a very high opinion of Mr. Bell's talents as an artist, as well as serve to show with what masterly skill Hunter prosecuted his researches in this branch of physiology. The seventh series illustrates the development of the ovum and its contents in Mammalia. The changes which the ovary undergoes subsequently to impregnation are first shown, in various animals. Then the changes going on in the uterus ; first, in such uteri as have horns, where the several ova are seen to occupy separate compartments; next, in uteri without horns, under which head are arranged a number of preparations of the uterus in woman, at different stages of pregnancy ; and these are followed by others, showing the changes which the uterus undergoes subsequently to parturition. The series is completed by a number of preparations designed to elucidate the structure of the placenta, and its connexion with the uterus, a point which has given rise to so much discussion of late. The eighth series shows the principal peculiarities of structure in the young animal during the foetal state, such as the yolk-bag, and its connexion with the foetus; the fcetal circulation'in birds; the horny knob on the beak used in breaking the shell; the reception of the yolk into the stomach ; the umbilical cord in Mammalia; THE LIFE OF JOHN HUNTER. 123 the open foramen ovale; the ventricles of the heart of equal thickness ; the situatibn and descent of the testes; the membrana pupillaris, and the large thymus gland. The ninth series illustrates the growth of the young, whether in plants or animals. The tenth and last series shows some of the various modes in which food and protection are furnished for the young animal; as, for instance, the glandular structure in the crop of pigeons, which secretes a kind of milk; the lactiferous glands of Mammalia; the young lodged in temporary cells on the back of the mother, as m the pipa frog; or carried in a pouch, as in the marsupial animals; or preserved in nests, as in birds, insects, &c. Having entered into so full an account of the Physiological Gallery, the remaining departments of the Museum must be treated of but briefly.

That which comes next to be noticed is the collection of objects in Comparative Anatomy preserved in a dry state. This department contains 745 specimens, of whch 617 belonged to the original Museum as left by Hunter. These are arranged in eleven series, which successivelv exhibit preparations of the heart and bloodvessels ; of the absorbents ; of the respiratory organs; of the digestive organs; of the male urino-genital organs ; of the same organs, with the lactiferous apparatus, in the female; of the nervous system; of the organs of vision ; and of the cutis. The tenth series contains models, casts, &c.; and the eleventh, several mummies. Various interesting and curious preparations are comprised under these several heads : the first affords a pretty full illustration of the various modes in which the aorta and its first branches arise in different animals; the sixth consists of the admirable preparations of the nerves which accompanied Mr. Swan's prize essay on this subject; in the tenth series are three wax models by the celebrated Clementi Susini; and amongst the mummies the most remarkable is that of Martin Van Buchell's wife, which was prepared by Cruikshank according to Dr. Hunter's directions, and given many years afterwards to the College by her son. The Catalogue of this department forms the fourth part of the General Catalogue in the course of publication.

The department of Human and Comparative Osteology is that which I shall next briefly notice. To the specimens here contained, very large and valuable additions have been made since Mr. Hunter's death. The original collection consisted of 963 preparations, to which 973 have since been added. The sources whence these have been derived are very various ; the most abundant has been 124 THE LIFE OF JOHN HUNTER. that of donations, but many of ihe rarest and most valuable skeletons were purchased by the College at the sale of Mr. Brookes's Museum. Only a fifth part of the valuable specimens contained in this department has vet been displayed, from a want of room in the present building; and upwards of 400 boxes, containing either the whole or a portion of the skeleton of various animals prepared by Mr. Hunter, remain shut up from public view. Of these, a manuscript catalogue is in the course of publication. The arrangement adopted for this department is that of Cuvier in his Regne Animal. At the head of the collection stands the skeleton of Charles Byrne, who measured eight feet four inches in height at his death; and as a contrast to his gigantic remains, we find here the skeleton of Mdlle. Crachami, an Italian dwarf, who, at the age of nine, when she died, measured only twenty inches in height. The order Bimana is further illustrated by a large collection of skulls, exhibiting the characters of the five great varieties of the human race, the Caucasian, Mongolian, American, ^Ethiopian, and Malay. The preparations from which the engravings in Hunter's work on the teeth were made are also deposited in this collection. Under the order Quadrumana we find the skeleton of the adult pongo, the chimpanze,and ournng-outang, and a few specimens from the family of lemurs. The large order Carnivora also contains many valuable skeletons, principally from animals of the true carnivorous tribes, as the Plantigrada, Digitigrada, and Amphibia. The Cheiropterus and Insectivorous genera are but scantily illustrated. The order Rodentia contains about a dozen skeletons, with several skulls of some of the rarer species. In the order Edentata we find a few valuable skeletons, amongst others one of the Rufous Ornithorhynchus. There are also several specimens of the Marsupiata. The order Pachydermata exhibits various specimens of the tusks, teeth, and skulls of elephants, as also the skeleton of Chuni, the large male elephant, whose violence necessitated his destruction some years since at Exeter 'Change; a skeleton of the hippopotamus, of the single-horned rhinoceros, and of the two-horned rhinoceros; as also the tapir, and of several of the smaller Pachydermata. The order Ruminantia is rich in skulls and horns of the antelope tribes, and of other genera, but contains few skeletons. ^ There is no adult skeleton of any of the larger species of the Cetaceous tribes except one of a young whalebone-whale, and about half a dozen skeletons of the smaller animals of this race. The class Aves, though illustrated by several valuable skeletons and a large collection of skulls, affords ample room for the donations of liberally disposed individuals. The same remark holds good of the class Reptilia. The class Pisces is very meagrely supplied with skeletons, which THE LIFE OF JOHN HUNTER. 125 no doubt chiefly arises from the difficulty experienced in preparing and preserving in place the bones of these animals. The Catalogue of this department forms the third part of the General Catalogue.

The department which next claims our attention is that containing preparations of monsters and malformations. These are disposed in two divisions, according as the preparations are preserved in spirit or in a dry state, and each division comprises four series, as arranged by Hunter. The first series contains examples of the preternatural situation of parts. The second, of the addition of parts. The third, of the deficiency of parts. The fourth, of hermaphroditism. Several curious and valuable preparations are contained in this collection; many have been added since Hunter's death. Amongst the latter are to be numbered two in the first series, which exhibit curious instances of one foetus becoming inclosed in the belly of another. The first is that which occurred to Mr. Highmore, of Sherborne; in which the foetus was encysted in the belly of a young man of seventeen. In the second, which occurred to Mr. G. Young, the containing child was six months old when it died. The histories of both have been published. Under the second head we find various examples of double parts in animals; amongst others,, of a double uterus and vagina in a woman, and one of the uteri containing a foetus of seven months. The case of deficiency of parts is exemplified by preparations of the heads of pigs and lambs, in the former of which animals malformations appear to be very common. In several of these the whole of the face which lies anterior to the ears is wanting; in others there is but one eye, in the centre of the forehead, with a proboscis from the forehead. Pigs so constructed go under the name of elephant pigs. The fourth series contains preparations from the hermaphrodite cow, or free-martin, on the generative organs of which Hunter wrote a paper in the Philosophical Transactions; as also of the organs of generation in hermaphrodite sheep and dogs. The organs of the hen pheasant, which has taken on the plumage of the cock, are also here exhibited. Amongst the series of dry preparations the most curious is that of a double skull, which belonged to a child of six years of age. The skulls are united by their vertices; the upper one was supplied by blood-vessels passing through the united portions; and from the account given by eye-witnesses, the upper head seems during life to have experienced sensations, and to have exhibited mental operations, distinct from those of the lower head. These preparations are described in the fifth part of the General Catalogue. 13 126 THE LIFE OF JOHN HUNTER. NATURAL HISTORY. 1. In spirit.—The next department of the Museum contains 2098 specimens of natural history preserved in spirit, of which 1743 belonged to the Hunterian collection. As yet only a catalogue of the invertebrate animals has been published, which amount to 614 in number. " This division," says Mr. Owen, who prepared the catalogue, " originated in the preservation of natural objects transmitted to Mr. Hunter for dissection, which accumulating as the reputation of the illustrious founder increased and extended, and as the requisite leisure for their examination became abridged, at length enabled him to exhibit in a series the most remarkable differences in the outward forms of the animal kingdom. They were arranged by him in the ascending order; this order has therefore been adhered to. and best accords with the position of the several classes of animals whose structures are shown in the Physiological Gallery. With a few exceptions, the classes and orders of Cuvier and Lamarck have been adopted. The invertebrate animals are arranged in two series, one ascending through the inarticulate, the other through the articulate classes." The Tunicata are arranged according to Mr. MacLeay's method. The Entozoa, after Rudolphi. The Cirripeds, after Dr. Leach. His genera have also been adopted for the Crustacea ; but the families and the orders are arranged according to Latrcille's method in Cuvier's Regne Animal. After the latter also the Insecta are arranged. f 2. Stuffed.—In addition to the specimens of natural history preserved in the foregoing department, the Museum contains a small collection of stuffed animals," and about 1000 dry specimens of insects, shells, zoophytes, &c, of which no catalogue has yet been published. 3. Fossils.—The collection of fossils contains 1415 specimens, of which two hundred have been added since the death of Hunter. There exists a manuscript catalogue of this department, with introductory remarks by Hunter, but this has not vet been published.

PATHOLOGY. Having thus taken a rapid sketch of the natural history departments of the Museum, a brief notice must now be given of the department of pathological anatomy. The preparations here contained are arranged under three heads. The first contains specimens of deceased parts preserved in spirit. The second, pathological preparations in a dry state. The third, the inorganic products of disease, as calculi, concretions, &c. 1. In Spirit.—Under the first head are arranged 1392 specimens, * An application is at present before the Privy Council for leave to dispose of the larger stuffed animals, which take up disproportionately the room of the Museum, while they only indirectly subserve the primary object of its formation. THE LIFE OF JOHN HUNTER. 127 of which 1084 constituted the collection as left by Hunter. They are disposed in three divisions, of which the first illustrates the actions of restoration and of disease in the various structures of the body. Examples of union by the first intention are first exhibited; to these succeed specimens of adhesive inflammation; of suppuration, under various circumstances; of ulceration, in its different forms; of granulation, as seen on different tissues ; of cicatrization; of the union of fractured bones. These are followed by a series illustrative of the effects of inflammation in bone, of diseases in joints, and of dislocation of bones. Diseases arising from pressure are next exemplified ; then the collection of fluids in cavities ; diseases of the circulating system; tumours not encysted; and finally, encysted tumours. In the second division the effects of specific or peculiar diseases are shown, as of scrofula, cancer, fungated ulcer, small-pox, gout, syphilis, gonorrhoea, hydrophobia. The third division contains specimens of disease, arranged according to their locality, beginning with diseases of the oesophagus, and proceeding to those of the stomach, intestines, and anus ; of the liver and gall-bladder; of the spleen, kidney, and urinary bladder; of the uterus and its appendages, in the impregnated and unimpregnated state; of the brain and its membranes; of the spinal cord and nerves ; of the eye; of the gums and teeth ; and lastly, of the air-passages and lungs. 2. Dry—Under the second head we find a large collection of dry preparations, illustrative of the actions of disease and restoration in bones, on which subject Hunter was preparing a work for publication at the time of his death. He bestowed great pains on the arrangement of these specimens, and left behind him very complete explanatory documents relating to them; but these, it is supposed, were committed to the flames by Sir Everard Home, along with the manuscripts which have been mentioned before. Besides the above specimens, we find under this head specimens of diseases occurring in teeth ; of diseases in the blood-vessels, lungs, intestines, and urinary organs ; besides,a variety of casts, and other miscellaneous objects. 3. Calculi.—The collection of calculi and concretion contains 1781 specimens, of which more than two thirds have been added since the death of Hunter. A manuscript catalogue of the whole has been completed, but the chemical composition of several of the specimens remains yet to be ascertained. I have endeavoured in the above outline to furnish a general conception of the character and contents of the Museum of Hunter. That it conveys but a faint idea of the real merits of this noble monument of his genius I am well aware. The brevity with which I have been compelled to speak of the several parts has necessarily prevented my entering into those details which would have given interest to the account, and under any circumstances a written description could furnish but an inadequate notion of the merits of this 128 THE LIFE OF JOHN HUNTER. work. He that would fully appreciate these must not only see the collection, but must examine each part with minute attention; for in this way alone can a correct idea be acquired of the skill displayed in the execution of the several parts, and of the comprehensive genius and indefatigable industry, the combination of which alone could have enabled him to plan and to execute so great an undertaking. Without doubt it is by this work, above all others, that Hunter has immortalized his name. In his writings we occasionally find an obscurity in the expression of his thoughts, a want of logical accuracy in his reasonings, and an incorrectness in his language, resulting from a deficient education. In this work no such failings are apparent; Nature is here made to be her own expositor, and the treasures she has poured forth come fresh to the mind from the fountains of knowledge, unimpaired by passing through the imperfect medium of language, and unimpeachablv proclaiming the genius of him by whose labours they were brought to light. That Hunter should have still left this work incomplete, after so many years devoted to its construction, will not surprise those who reflect that the stores of Nature are in truth inexhaustible. He has raised a noble edifice, the magnitude and beauty of which all must admire who consider that it was the work of one mind ; but there is still ample room for the labours of others in adding to or completing its various parts; and those to whose care this invaluable collection has been committed could not have better forwarded the interests of science than by devoting, as they have done, some of the ample funds at their disposal to judiciously increasing its treasures, and to making those treasures more extensively useful by publications, such as those by which they are now illustrating them. It has long been a subject of just regret that the building in which the Museum is at present contained, does not afford room for the display of more than one half of the whole collection. The Council have therefore determined on increasing the accommodation, by the incorporation of the two adjoining houses, so as to form one uniform building, in which particular attention has been paid to ensure the complete illumination of every part, a point in regard to which the present premises are remarkably defective.* This building is now rapidly advancing, and will probably be completed in about a twelvemonth, by which time also the remaining parts of the General Catalogue will be far advanced. In addition to this the College has provided, at an expense of upwards of

* It is perhaps to be regretted that the Council of the College should have come to the resolution of building upon their present site, where they are confessedly so much cramped for room. The accumulated and yearly funds of the College, amounting in 1832 to upwards of 66,000/. in hand, and 11 000/ per annum, might justly have warranted a more enlarged plan, commensurate with the trust reposed in their hands, and with the expectation of further increase which they have a right to entertain. The building, however, which is now in progress will form a noble object in the metropolis, and be a great improvement upon the former one. r THE LIFE OF JOHN HUNTER. 129

10,000/., a magnificent library, to which valuable additions are now being made; so that when these and the before-mentioned arrangements are completed, the surgical profession in England will have reason to boast of possessing one of the noblest scientific establishments which the world can exhibit. 13* APPENDIX. Chronological List of Mr. Hunter's Writings.

1762. 1. On the Descent of the Testis—Medical Commentaries, by Dr. Wm. Hunter. Part I. p. 75; and Animal (Economy. ---- 2. On Absorption by Veins—Med. Comm. p. 42. 1766. 3. An account of an amphibious Bipes, by J. Ellis, with supplement by J. Hunter—Phil. Trans. 1771. 4. Treatise on the Natural History of the Human Teeth, Part I. 1772. 5. On the Digestion of the Stomach after death—Phil. Trans., and Animal (Economy. 1773. 6. Anatomical Observations on the Torpedo—Phil. Trans. 1774. 7. An account of certain receptacles for air in Birds, which communicate with the lungs and Eustachian tubes, &c.—Phil. Trans., and Animal (Economy. ---- 8. Observations on the Gillaroo Trout, commonly called in Ireland the Gizzard Trout—Phil. Trans., and Animal (^Economy. 1775. 9. An account of the Gymnotus electricus—Phil. Trans. ---- 10. Experiments on Animals and Vegetables, with respect to the power of producing heat—Phil. Trans., and Animal GSconomy. 1776. 11. Proposals for the recovery of people apparently drowned —Phil. Trans., and Animal CEconomy.

12. Croonian Lectures on Muscular Motion (never printed).

13. On the Heat of Animals, &c.—Phil. Trans., and Animal (Economy. 1778. 14. Treatise on the Natural Historv of the Human Teeth, Part II. 1779. 15. An account of the Free Martin—Phil. Trans., and Animal (^Economy. 1780. 16. Account of a Woman who had the smallpox during pregnancy, and who seemed to have communicated the same disease to the foetus—Phil. Trans. APPENDIX. 131 1780. 17. An account of an extraordinary Pheasant—Phil. Trans. and Animal (Economy. 1782. 18. Account of the Organ of Hearing in Fishes—Phil. Trans., and Animal (Economy. 1784. 19. Observations on the inflammation of the internal coats of veins—Transactions of a Society for the Improvement of Medical and Chirurgical Knowledge, vol. i. 1785. 20. Description of a new Marine Animal, in a letter from Mr. Everard Home to J. Hunter, F.R.S., with a postscript by Mr. Hunter, containing anatomical remarks upon the same—Phil. Trans. 1786. 21. Treatise on the Venereal Disease. ---- 22. Observations on certain parts of the Animal (Economy, being a republication of certain papers above mentioned, in the Phil. Trans., to which were added the nine following: 23. A description of the situation of the Testis in the Foetus, with its descent into the scrotum. 24. Observations on the glands situated between the rectum and the bladder, called vesiculae seminales. 25. On the Structure of the Placenta. 26. Some observations on Digestion (almost an entirely new paper). 27. On a secretion in the crop of breeding Pigeons for the nourishment of their young. 28. On the colour of the Pigmentum nigrum in different animals. 29. The use of the oblique Muscles. 30. A description of the Nerves which supply the Organ of Smelling. 31. A description of some branches of the fifth pair of Nerves. 1787. 32. Observations tending to show that the Wolf, Jackall, and Dog are all of the same species—Phil. Trans, and Animal (Economy, 2d Edit. ---- 33. An experiment to determine the effect of extirpating one ovarium upon the number of young produced.—Phil. Trans., and Animal (Economy, 2d Edit. ---- 34. Observations on the Structure and (Economy of Whales. —Phil. Trans. 1789. 35. Supplement to the paper on the Wolf, Jackal, and Dog. —Phil. Trans., and Animal (Economy, 2d Edit. ---- 36. On Introsusception.—Transactions of a Society, &c, vol. i. ---- 37. An account of Mr. Hunter's method of performing the operation for the cure of Popliteal Aneurism, by Everard Home, Esq., from materials furnished by Mr. Hunter.—Transactions of a Society, &c, vol. i. and ii. 132 THE LIFE OF JOHN HUNTER. > Journal of a Voyage to New South Wales, by John White, Esq. 1790. 38. A case of Paralysis of the Muscles of Deglutition cured by an artificial"mode of conveying food and medicines into the stomach.—Transactions of a Society, &c, vol. i. ---- 39. Some observations on the loose cartilages found in joints, and most commonly met with in that of the knee, by Everard Home, Esq., from materials furnished by Mr. Hunter.—Transactions of a Society, &c, vol. i. ---- 40. General observations on the mode of collecting and sending home animals, and on the nomenclature and classification of animals.—Journal of a Voyage to New South Wales, by John White, Esq. ---- 41. Description of the Kangaroo. ---- 42.----------------Wha Tapoau Roo. ---- 43.----------------Dingo, or Wild Dog of Australia. ---- 44.----------------■ Tapoa Tafa or Tapha. ---- 45.----------------Poto Roo, or Kangaroo Rat. ---- 46.----------------Hepoona Roo. J 1791. 47. Observations on certain horny excrescences of the human body, by Everard Home, F. R. S., from materials furnished by Mr. Hunter.—Phil. Trans. 1792. 48. Observations on Bees.—Phil. Trans. 1793. 49. Some facts relative to the late Mr. J. Hunter's preparation for the Croonian Lectures, by E. Home, Esq.— Phil. Trans. ^ 1794. 50. Observations on the Fossil Bones presented to the Royal Society, by the Margrave of Anspach, by the late Mr. J. Hunter.—Phil. Trans. 1794. 51. Treatise on the Blood* Inflammation, and Gun-shot Wounds. ---- 52. The case of a young Woman who poisoned herself in the first month of pregnancy, by Thomas Ogle; to which is added an account of the appearances after death, by the late J. Hunter.—Transactions of a Society, &c, vol. ii. J ---- 53. Mr. Hunter's opinion concerning the Anatomy of the Camel's Stomach.—Natural History of Aleppo, by Alexander Russel, Esq., 2d Edit. vol. ii. p. 419. ---- 54. Notes on the Anatomy of the Jerboa, by Mr. Hunter — Ibid., vol. ii. p. 419. 1798. 55. Experiments and observations on the growth of Bones, from the papers of the late Mr. Hunter, by Everard Home, b. K. S.—Transactions of a Society, &c, vol. ii. APPENDIX. 133 Some account of the Editions of Mr. Hunter's Works.

TREATISE ON THE NATURAL HISTORY OF THE HUMAN TEETH.

Parti. 4to. 1771. 1st Edit, i part n 4tQ> 1?78 On the occasion of the publication of Part II. a new title-page was added to Part I., and the two (being bound together) were sold as the second Edition. 2d Edit. 1778.—The circumstances of this Edition are explained above. 3d Edit. 4to. 1803. / A few unimportant alterations in the disposition of the prefatory parts of the work are made in this edition.— No pains seem, however, to have been taken to rectify any of the errors of the former editions. The drawings from which the engravings were made having been marked by Mr. Hunter with the initial capital letters A, B, C, &c, instead of by the Roman numerals I. II. III., &c, the engraver mistook the I for the J, <fcc, and thus innumerable errors in the references arose, which rendered the explanations to several of the plates absolutely unintelligible in all the former editions. TREATISE ON THE VENEREAL DISEASE. 1st Edit. 1786. 4to. 2d Edit. 1788. 4to. The alterations in the Second Edition were mostly verbal. Both the First and Second Editions were printed and published at Mr. Hunter's own residence. 3d Edit. 4to. with Notes by Sir Everard Home. This was printed by some mistake from the First, instead of from the Second Edition, and is therefore chargeable with all those errors which Mr. Hunter was at so much pains to correct. The Editor has not only added notes at the foot of the page, but has incorporated his own remarks in the body of the text, without the insertion of any marks by which they may be distinguished. He has also omitted whole paragraphs, or parts of paragraphs, in several parts of the work, without any apparent authority for so doing. The work is illustrated by the original plates. 4th Edit. 1810. 1 vol. 8vo. with Notes by Dr. Joseph Adams. This is a pretty correct reprint from the Second Edition. Dr. Adams, however, was too enthusiastic an admirer of Hunter to admit of his seeing any defects in the works of his favourite author; and consequently his notes rarely apply themselves to the real difficulties or defects of the work, but rather manifest a determination to uphold the opinions of his friend at all events. The plates which illustrate this edition are reduced from the 4to plates, and cannot be commended. 134 THE LIFE OF JOHN HUNTER. 5th Edit, j J®0**' j 4to. with Notes by Sir Everard Home, Bart.

Being the Second Edition by this Editor, in which, however, few deviations from the First are observable. A supposititious title-page, purporting to be the Third Edition, seems to have been added in 1810, in order to increase the sale.

OBSERVATIONS ON CERTAIN PARTS OF THE ANIMAL 02CONOMY. 1st Edit. 1786. 4to. 2d Edit. 1792. 4to. Both these Editions were printed and sold at Mr. Hunter's own residence. The Second Edition contains two additional papers, as well as some additional plates illustrative of the papers contained in the First Edition. The alterations are exceedingly numerous in every part of the work, and, upon the whole, considerable additions are made.

TREATISE ON THE BLOOD, INFLAMMATION, AND GUNSHOT WOUNDS. 1st Edit. 1794. 4to. Was about one third through the press when Mr. Hunter died. It possesses no index. Its punctuation is extremely erroneous, the language often obscure, and the printing very inaccurate. These defects must be ascribed to the circumstance of Mr. Hunter's death, and the neglect which the work afterwards suffered. A Life, by Sir Everard Home, is prefixed. 2d Edit. 1812. 2 vols. Svo. 3d Edit. 1818. 2 vols.'8vo. 4th Edit. 1828. 1 vol. 8vo. These are merely reprints of the errors as well as of the other matters contained jn the first 4to Edition. The plates are reduced from the 4to plates, and cannot be praised as specimens of the art of engraving. None of these Editions contain any Index, or Life of the author. Mr. Hunter's Evidence on the Trial of John Donellan, Esq for the wilful Murder, by poison, of Sir Theodosius Edward Allesley Bougiitox, Bart, at the Assizes at Warwick, on Friday, March 20, 1781.* *'

(Taken in Short Hand by J. Gurney, Esq.) Mr. John Huxter sworn: Examined by Mr. Newnham. Q. Have you heard the evidence that has been given by these gentlemen ?—A. I have been present the whole time? * See Life, p. 62. APPENDIX. 135 Q. Did you hear Lady Boughton's evidence ?—A. I heard the whole. Q. Did you attend to the symptoms Her Ladyship described, as appearing upon Sir Theodosius Boughton, after the medicine was given him ?—A. I did. • , . Q. Can any certain inference, upon physical or chirurgical principles, be drawn from those symptoms, or from the appearances externally or internally of the body, to enable you, in your judgment, to decide that the death was occasioned by poison 1—A. I was in London then; a gentleman who is in Court waited upon me with a copy of the examination of Mr. Powell and Lady Boughton, and an account of the dissection, and the physical gentlemen's opinion upon that dissection. Q. I don't wish you to go into that; I put my question in a general way.—J. The "whole appearances upon the dissection explain nothing but putrefaction. Q. You have been long in the habit of dissecting human subjects. I presume you have dissected more than any man in Europe'?—A. I have dissected some thousands during these thirty-three years. Q. Are those appearances you have heard described such, in your judgment, as are the result of putrefaction in dead subjects?— A. Entirely. Q Are the symptoms that appeared after the medicine was given such as necessarily conclude that the person had taken poison ?—A. Certainly not. Q. If an apoplexy had come on, would not the symptoms have been nearly or somewhat similar ?—A. Very much the same. Q. Have you ever known or heard of a young subject dying of an apoplectic or epileptic fit?—A. Certainly; but with regard to the apoplexy, not so frequent; young subjects will perhaps die more frequently of epilepsies than old ones; children are dying every day from teething, which is a species of epilepsy arising from an irritation. Q. Did you ever, in your practice, know an instance of laurelwater being given to a human subject?—A. No, never. Q. Is any certain analogy to be drawn from the effects of any given species of poison upon an animal of the brute creation, to that it may have upon a human subject?—A. As far as my experience goes,'which is not a very confined one, because I have poisoned some thousands of animals, they are very nearly the same ; opium, for instance, will poison a dog similar to a man; arsenic will have very near the same effect upon a dog as it would have, I take it for granted, upon a man. I know something of ihe effects of them, and I believe their operations will be nearly similar. Q. Are there not many things which will kill animals almost instantaneously, that will have no detrimental or noxious effect upon a human subject; spirits, for instance, occur to me ?—A. I apprehend a great deal depends upon the mode of experiment; no man is fit to make one but those who have made many, and paid considerable attention to all the circumstances that relate to experiments. It is 136 THE LIFE OF JOHN HUNTER. a common experiment, which I believe seldom fails, and is in the mouth of everybody, that a little brandy will kill a cat: I have made the experiment and have killed several cats, but it is a false experiment ; in all those cases where it kills the cat, it kills the cat by getting into her lungs, not into her stomach; because if you convey the same quantity of brandy, or three times as much, into the stomach, in such a way as the lungs shall not be affected, the cat wilf not die. Now in those experiments that are made by forcing an animal to drink, there are two operations going on; one is, a refusing the liquor by the animal, its kicking and working with its throat to refuse it; the other is, the forcing the liquor upon the animal: and there are very few operations of that kind but some of the liquor gets into the lungs ; I have known it from experience. Q. If you had been called upon to dissect a body suspected to have died of poison, should you or not have thought it necessary to have pursued your search through the guts ?—A. Certainly. Q. Do you not apprehend that you would have been more likely to receive information from thence than any other part of the frame?— A. That is the track of the poison, and I should certainly have followed that track through. Q. You have heard of the froth issuing from Sir Theodosius's mouth a minute or two before he died : is that peculiar to a man dying of poison, or is it not very common in many other complaints ?—A. • I fancy it is a general effect of people dying in what you may call health, in an apoplexy, or epilepsy, in all sudden deaths, where the person was a moment before that in perfect health. Q. Have you ever had an opportunity of seeing such appearances upon such subjects?—A. Hundreds of times. Q. Should you consider yourself bound, by such an appearance, to impute the death of the subject to poison ?—A. No, certainly not; I should rather suspect an apoplexy; and I wish in this case the head had been opened, to remove all doubts. Q. If the head had been opened, do you apprehend all doubts would have been removed ?—A. It would have been still further removed, because although the body was putrid, so that one could not tell whether it was a recent inflammation, yet an apoplexy arises from an extravasation of blood in the brain, which would have laid in a coagulum. I apprehend, although the body was putrid, that would have been much more visible than the effect any poison could have had upon the stomach or intestines. Q. Then in your judgment, upon the appearances the gentlemen have described, no inference can be drawn from thence that Sir Theodosius Boughton died of poison?—A. Certainly not; it does not give the least suspicion.

Mr. John Hunter, cross-examined by Mr. Howorth.

Q. Having heard the account to-day that Sir Theodosius Boughton, APPENDIX. 137 apparently in perfect health, had swallowed a draught which had produced the symptoms described, I ask you whether any reasonable man can entertain a doubt that that draught, whatever it was, produced those appearances 1—A. 1 don't know well what answer to make to that question. Q. Having heard the account given of the health of this young gentleman on that morning, previous to taking the draught, and the symptoms that were produced immediately upon taking the draught, I ask your opinion, as a man of judgment, whether you don't think that draught was the occasion of his death 1—A. With regard to his being in health, that explains nothing; we frequently, and *ndeed generally, see the healthiest people die suddenly, therefore I shall lay little stress upon that: as to the circumstances of the draught, I own they are suspicious: every man is just as good a judge as I am. . Court.—You are to give your opinion upon the symptoms only, not upon any other evidence given. Mr. Howorlh.—-Upon the symptoms immediately produced, after the swallowing of that draught, I ask whether, in your judgment and opinion, that draught did not occasion his death?—A. I can only say, that it is a circumstance in favour of such an opinion. Court.—That the draught was the occasion of his death?—A. No : because the symptoms afterwards are those of a man dying, who was in perfect health; a man dying of epilepsy or apoplexy, the symptoms would give one those general ideas. Court.—It is the general idea you are asked about now, from the symptoms which appeared upon Sir Theodosius Boughton immediately after he took the draught, followed by his death so very soon after ; whether, upon that part of the case, you are of opinion that the draught was the occasion of his death 1—A. If I knew the draught was poison I should say, most probably, that the symptoms arose from that; but, when I don't know that the draught was poison, when I consider that a number of other things might occasion his death, I cannot answer positively to it. Court.—You recollect the circumstance that was mentioned of a violent heaving in the stomach 1—A. All that is the effect of the voluntary action being lost, and nothing going on but the involuntary- . • • *u Mr. Howorth.—Then you decline giving any opinion upon the subject?—.#. I don't form any opinion to myself; I cannot form an opinion, because I can conceive if he had taken a draught of poison, it arose from that: I can conceive it might arise from other causes. Q. If you are not at all acquainted with the effects and operations of distilled laurel-water, whether the having swallowed a draught of that would not have produced the symptoms described?—^. 1 should suppose it would ; I can only say this of the experiments 1 have made of laurel-water upon animals, it has not been near so quick. I have injected laurel-water directly into the blood of dogs, 14 138 THE LIFE OF JOHN HUNTER. and they have not died ; I have thrown laurel-water, with a precaution, into the stomach, and it never produced so quick an effect with me, as described by those gentlemen. Q. But you admit that laurel-water would have produced symptoms such as have been described ?—A. I can conceive it might. Mr. JVewham.—Would not an apoplexy or an epilepsy, if it had seized Sir Theodosius Boughton at this time, though he had taken no physic at all, have "produced similar symptoms too ?—A. Certainly. Q. Where a father has died of an apoplexy, is not that understood, in some measure, to be constitutional?—A. There is no disease whatever that becomes constitutional but what can be given to a child. There is no disease which is acquired that can be given to a child ; but whatever is constitutional in the father, the father has a power of giving that to the children; by which means it becomes what is called hereditary. There is no such thing as an hereditary disease, but there is an hereditary disposition for a disease. Mr. Howorth.—Do you call apoplexy constitutional ?—A. We see most diseases are constitutional: the small-pox is constitutional, though it requires an immediate cause to produce the effects. The venereal disease is hereditary. I conceive apoplexy as much constitutional as any disease whatever. Q. Is apoplexy likely to attack a thin young man who had been in a course of taking cooling medicines before ?—A. Not so likely, surely, as another man; but I have, in my account of dissections, two young women dying of apoplexies. Q. But in such a habit of body, particularly attended with the circumstance of having taken cooling medicines, it was very unlikely to happen ?—A. I do not know the nature of medicine so well as to know that it would hinder an apoplexy taking effect. Court.—Give me your opinion in the best manner you can, one way or the other, whether, upon the whole of the symptoms described, the death proceeded from that medicine or any other cause? —A. I do not mean to equivocate ; but when I tell the sentiments of my own mind, what I feel at the time, I can give nothing decisive. Extract from Mr. Justice Buller's Charge.

" For the prisoner you have had one gentleman called, who is likewise of the faculty, and a very able man. I can hardly say what his opinion is, for he does not seem to have formed any opinion at all of the matter. He, at first, said he could not form an opinion whether the death was, or was not, occasioned by the poison, because he could conceive that it might be ascribed to other APPENDIX. 139 causes. I wished very much to have got a direct answer from Mr. Hunter if I could, what, upon the whole, was now the result of his attention and application to the subject, and what was his present opinion ; but he says he can say nothing decisive. So that, upon this point, if you are to determine upon the evidence of the gentlemen who are skilled in the faculty only, you have the very positive opinion of four or five gentlemen of the faculty that the deceased did die of poison. On the other side, you have what I really cannot myself call more than the doubt of another; for it is agreed by Mr. Hunter, that the laurel-water would produce the symptoms which are described. He says, an epilepsy or apoplexy would produce the same symptoms; but, as to an apoplexy, it is not likely to attack so young and so thin a man as Sir Theodosius was ; and, as to an epilepsy, the other witnesses tell you, they don't think the*symptoms which have been spoken of do show that Sir Theodosius had any epilepsy at the time. THE END. LECTURES PRINCIPLES OF SURGERY BY JOHN HUNTER, F.R.S. WITH NOTES JA~MES F. PALMER, SENIOR SURGEON TO THE ST. GEORGe's AND ST. JAMF.s's D1SFENSART, FELLOW OF THK ROTAL MEDICAL AND CHIRURGICAL 90CIETT OF LONDON, ETC., ETC. HASWELL, BARRINGTON, AND HASWELL, 293 MARKET STREET. 1841. PREFACE. The following Lectures are printed from a very full and accurate copy, taken in short-hand by Mr. Henry Rumsey of Chesham, to wThom I am indebted for the permission to make them public. They were delivered in the years 1788 and 1787, after which period I have not found any copy, excepting a very short and imperfect one in the Museum of the Royal College of Surgeons, dated 1791, by Mr. James Pearce. There are also in the College Museum five other copies, which are respectively attributed to Mr. Twigge, Mr. Hopkinson, Mr. Parkinson, and Mr. R. Keate; the fifth being only a partial transcript of a copy by Dr. Joseph Adams, Mr. Hunter's biographer. Of all these, Mr. Parkinson's is by far the most full and accurate, although in these respects it falls very far short of the accuracy and fullness of Mr. Rumsey's copy, from which the ensuing lectures are printed. Indeed, from the fullness of the latter, one might almost suppose that the writer had had access to the Hunterian manuscript; for, besides being generally more full, it never omits examples and illustrations in proof of opinions, which the former ones frequently do. The style also is characteristically Hunterian. I am also indebted to Sir. Benjamin Brodie, to Professor Macartney, and to Mr. Frederick Tyrrel, for the use of copies in their possession, the first of which is ascribed to Mr. Howison, the second was taken by the Professor himself, and the third by Mr. Robert Lees. The last of these (bearing date 1785 and 1786) is the most valuable, being not only the most full, but abounding with interlineations, which there is every reason to believe were added during 4 PREFACE. an attendance upon a second course of the same Lectures. These last-mentioned copies, as well as Mr. Parkinson's, have been had recourse to whenever occasion required, but in general, and with very few exceptions, the printing has been conducted from Mr. Rumsey's. Occasionally it has been found necessary to retrench redundancies and repetitions, and to substitute one word for another having a synonymous signification. The value of these Lectures, I suppose, will not be questioned, nor the interest which attaches to them denied. Besides the luminous general views on Physiology and Pathology which they contain, they also abound in useful facts and the most valuable practical suggestions. In some respects they may be regarded as amplifications of his published opinions, but in other respects they enter upon entirely new subjects of the greatest interest to the Surgeon. The notes which accompany these Lectures are not numerous ; for as many of the subjects treated of will again come under consideration in the course of the Treatises, it seemed more convenient to refer any observations that might be required, to those parts of the work, in which the Author has expressed his opinions in his own undoubted language. In the few observations which the Editor has deemed it necessary to make, he has sometimes had recourse to authorities, which he has not always thought it necessary to mention particularly. He trusts, however, that this general acknowledgment will obviate the suspicion of his wishing to appropriate unjustly the labours of other men.

JAMES F. PALMER. 38 Golden Square, April, 1835. CONTENTS. Chap. I. Introductory Remarks on the Study of Physiology, and on Physical and Vital Laws. II. Of Life. III. Of the Blood. IV. General Views of Organization and Action, V. Of the Functions of Nutrition and Absorption. VI. Of the Brain and Nerves, and of Sleep. VII. Of Susceptibility of Impressions ; of Stimuli; of Dispositions of the Body ; of Habit and Custom. VIII. Of the Heat of Animals. IX. General Principles of Disease. X. Of Sympathy. XL Of Local and Constitutional Diseases. XII. General Principles of Inflammation, and of Ecchymoses. XIII. Of Adhesive Inflammation. XIV. Of Suppurative and Ulcerative Inflammation; Granulation; Skinning; Hectic Fever, and Dissolution. XV. Practical illustrations of the preceding subjects; Hernia ; Ruptured Tendons ; Phlebitis, &c. &c. XVI. Of Hydrocele; Diseased Testicle, &c. XVII. Of Gunshot Wounds and Injuries of the Head. XVIII. Of Diseases of the Bones and Joints ; Fractures ; Dislocations, &c. &c. XIX. Of Hemorrhages and Aneurism. XX. Of Specific Diseases ; Varicose Veins ; Tumours; Hydatids, &c. &c. XXL Of Scrofula; Lumbar Abscess; Scrofula of the Testicle and Breast, &c. &c. XXII. Of Mortification and Carbuncle. XXIII. Of Poisons ; Itch ; Cancer; Fungated Ulcers, &c. &c. 1* LECTURES

PRINCIPLES OF SURGERY. CHAPTER I.

Introductory remarks.—These lectures to contain the results of Mr. Hunter's own observation;—intended to explain the general principles of the art;—these the necessary guides to practice.—Mr. Hunter's opinion of operations;—motives for lecturing.—To commence with some account of physiology.—Preliminary observations on matter;—.its general properties;—rour perception of matter: — attraction;—repulsion;—properties added to constitute organized matter.—Of animal and vegetable matter;—its origin in, and return to, common matter;— but distinguished from it by peculiar properties;—growth;—propagation of the species:—existence under two states, the living and the dead;—three modes in which it may be considered: 1st, Living; 3d, Chemically when dead; 3d, In a state of decay, and return to common matter.—.-Errors of former physiologists, in explaining vital actions by mechanical or chemical operations;—this error to be corrected.—Consideration of animal matter in particular ;—and especially of the human body;—but information to be drawn from other animals and vegetables {^•also from diseases and malformations,

Mr. Hunter used generally to commence by stating that it was his intention, in these lectures, to give only the results of his own observations and experience, because the opinions of others might be found in their works. I do not mean, said he, that all I say in this course will be entirely new, and that none of the opinions and observations which I shall deliver are to be found in any publications, for there are many facts too obvious to have been overlooked in the most ignorant days of physic. I intend in this course to in* elude some of the most interesting parts of surgery, principally those subjects on which I have had opportunities of making many new, and I hope useful observations, so as to put our art, in many respects, in a new point of view. Many of my ideas, and the arrangement of my subject, are new, and consequently my terms become in part new, for two ideas cannot be expressed in the same terms. I am led to suppose my ideas are just, because they have 8 HUNTER'S PRINCIPLES OF SURGERY. in some measure stood the test of time; and what is the most incontestible proof of their correctness is, that they have been adopted by others; and I hope my terms will be found expressive of the things meant, and that they are so appears evident, from their having been employed in several late publications on surgery. I do not intend to give my lectures as a regular course, but rather to explain what appear to me to be the principles of the art, so as thereby to fit my pupils to act as occasion may require, from comparing and reasoning on known principles. I shall suppose you ^ already acquainted with the structure of the parts of the human frame, and must observe, that a knowledge of the healthy and diseased actions, or, in other words the principles of our art, are not less necessary to be understood than the principles of other sciences; unless, indeed, the surgeon should wish to resemble the Chinese philosopher, whose knowledge consisted only in facts. In . that case the science must remain unimproved until fresh facts arise. In Europe philosophers reason from principles, and thus "account for facts before they arise. Too much attention cannot be l paid to facts; yet too many facts crowd the memory without advantage, any further than that they lead us to establish principles. By an acquaintance with principles we learn the causes of diseases. Without this knowledge a man cannot be a surgeon. Surgeons v have been too much satisfied with considering the effects only; but in studying diseases we ought not only to understand the effect, as ■ inflammation, suppuration, &c, but also the .cause of that effect; for without this knowledge our practice must be very confined, and often applied too late, as in many cases it will be necessary to prevent the effect. In the bite of a mad dog, for instance, the disease will be prevented by removing the part; in the venereal disease, in the case of chancre, we must not only know how to cure the chancre, but also to prevent its effects on the constitution, which is done by giving mercury internally. On the other hand, it would be often proper to increase the effect, which can only be done when we know the cause.* In many cases, where the effect could not be

* [By the " law of nature" is meant the invariableness or uniform constancy of certain results following certain given conditions, the agents (which for the most part are unknown and invisible), being denominated the cause, the resulting phenomena the effect, and the conditions under which that effect is produced, the law. Thus, all bodies fall to the earth, and all bodies also suffer an expansion of their particles by the application of heat. Here the principles of gravitation and heat are the causes, the descent and expansion of the bodies, the effects, and the rates according to which these effects take place, the laws of Gravitation and heat. Causation is attributed merely in consequence of the invariableness of the phenomena, and not in consequence of any knowledge which we possess of the intimate relation of causes and effects. It is not in general difficult to deduce the laws of physical agents, in consequence of the power which we possess of simplifying and varyinc the conditions of our experiments, so as in the first instance to separate all extraneous influences or disturbing causes, and in the second place to verify the results thus obtained by every possible combination of opposing circumstances. Such certainty, however, is rarely attainable in regard to organised bodies in consequence INTRODUCTION. 9 prevented, or afterwards either removed, diminished, or increased with advantage, it will be proper to change it to some other more in our power to remove, as, for instance, by converting the venereal into common inflammation. If the disease is already formed, we ought to know the modes of action in the bodtf and in parts, in their endeavour to relieve themselves; the powers they have of restoring themselves, and the means of assisting those powers. Or, if these prove insufficient, we judge, by all the attending circumstances, how far excision may be necessary, and what condition of the constitution is most favourable for an operation. To determine on this last point is exceedingly difficult, and in some instances exceeds our present knowledge. I lately saw a patient die in a few hours, of no other operation than the excision of a small tumour from the arm ; another, by the removal of one from the abdomen; a third, by castration; and within these two days I assisted at an operation for fistula in perinaeo, sixteen hours after which the patient died. Now all these patients seemed previously in good health, and perhaps the cause of death, and the particular circumstances . of the constitution which render operations thus hazardous, will never be understood. This last part of surgery, namely, operations, is a reflection on . the healing art ; it is a tacit acknowledgment of the insufficiency of surgery. It is like an armed savage who attempts to get that by force which a civilized man would get by stratagem. No surof tbe reaction of the parts of which they consist upon one another, and the consequent impossibility of observing the effects of organic agencies In their simple state. The conditions under which any given class, of phenomena are observed are continually varying, and a variety of extraneous causes are mixed up in almost every case, so that, from the most careful experiments, it is still extremely possible to mistake the conclusion, and to deduce laws which are expressive only of a part of the facts. These circumstances afford no just ground for under-valuing physiological principles, although they are calculated to inspire a wary caution in arguing with too much positiveness from principles of this kind. We would say, " Est quodam prodire tenus si non datur ultra." It is scarcely necessary to observe that causes differ greatly among themselves. It would be absurd to confound the principle of heat, the expansion of steam, and the machinery by which the power thus generated acts, as causes of the same kind. The remote and the proximate cause in such a case have no immediate relation, but are connected together by a number of intermediate circumstances which, like the steps of an argument, unite the conclusion to the premises. It is very necessary to bear this in mind in physiological reasoning, in consequence of our almost total ignorance of these intermediate links in the chain of causation. In the instance above adduced by the author, we have no knowledge of the mode in which the poison of a rabid animal, or the poison of syphilis, produce their effects on the animal body ; nor how mercury and other medicines should tend to eradicate the latter from the constitution. We are unable in these cases to advance a step further than to perceive the necessity of absorption of the poison, after which all is conjecture. A full perception of the whole sequence of effects would doubtless at once discover the precise nature of the remedy, as well as the proper cases in which it should be administered. These few observations have been made in consequence of the indefinite and not very philosophical manner in which Mr. Hunter sometimes employs the word cause. The final and efficient causes are frequently confounded.] 10 HUNTER'S PRINCIPLES OF SURGERY. geon should approach the victim of his operation without a sacred dread and reluctance, and should be superior to that popular eclat generally attending painful operations, often only because they are so, or because they are expensive to the patient. Mr. Hunter next mentioned his motives for lecturing; showing that he did not do this with a view to pecuniary gain, since the time thus expended might be employed more profitably in extending his connexions and enlarging his practice. I have seen, said he, as much practice, and made a larger collection of diseased preparations than perhaps any man in Europe, all of which I find to correspond with the opinions I have formed of the nature of the respective diseases. In the years 1761 and 1762, having been already engaged ten years in the profession, I attended the army, without which I should have been unable to give my opinion concerning gunshot wounds, which rarely occur in civil practice. In the year 1768 I was called upon to be a teacher of anatomy, but I congratulate myself that I did not become so, as it could not have failed of engaging my attention too much to admit that general attention I have been able to pay to surgery; and the necessity I should have been under to read might have occupied me too much, and prevented my forming habits or established modes of thinking.— In the years 1772, 1773, and 1774, I had frequent opportunities of giving my opinion in private, and had generally the satisfaction to be heard with candour. Since I have lectured, I have scarcely found a pamphlet without some of my opinions, and often my very language, as adhesive and suppurative inflammation, &c. But what more than all induced me to lecture, was the great advantage every one finds by putting his thoughts into writing. A man can never tell how much he knows till he arranges his knowledge, and then he can tell how defective it is; hence it is that almost all the authors of any consideration in physic have been public teachers. In the present lectures it is my intention to begin with the physi- * ology of the animal economy in its natural or healthy state ; and then to come to pathology, or the physiology of disease, which may be called the perversion of the natural actions of the animal economy. Amongst the latter I shall treat first of accidents the most simple or natural, or diseases spontaneously arising; next, of the means of restoration, on which I shall be particularly full,—of these the first is adhesive inflammation, commonly called healing by the first intention; then of inflammations tending to suppuration, granulation, and cicatrization : after these I shall consider the specific diseases, as locked jaw, scrofula, &c.: the poisons next, as the venereal disease, cancer, &c. Of Matter; and first of the Distinction between Animate and Inanimate Matter.

I must now beg the close attention of the gentlemen present, as INTRODUCTION. 11 I shall be a little abstruse in the present lecture, which I intend as an introduction to all animal matter. Before we endeavour to give an idea of an animal, it is neces- t sary to understand the properties of that matter of which an animal is composed; but the better to understand animal matter, it is necessary to understand the properties of common matter; else we shall be often applying our ideas of common matter, which are familiar to us, to animal matter, an error hitherto too common, but which we should carefully avoid. By our senses alone is matter demonstrable. If a man did not see, he would have no conception that there was such a thing as liaht; if he was deaf, he could have no idea of sound; if he had no touch, no taste, no smell, in short if he had no sensation at all, (which is easily conceivable), he would not know that there is such a thing existing as matter. On the other hand, it is from matter alone that we come to a knowledge of our senses ; so that the only proof of the existence of either is by their reciprocal effects. An animal, then, must be composed in such a manner as to be susceptible of impression, which impression consists of an alteration in the part impressed ; and matter must make the impression on us before we can become sensible of its existence. Matter is in itself, however, only an abstract idea, and it is not the matter itself but some of its properties which make the impression, as sourness, heat, &c. When we see a man, it is not the man himself or the matter of the man that makes the impression, but the light which he reflects, and which our eye has the power of collecting to one point, so as to give a determinate shape on the organ of sight. Now the act of seeing is that impression made on our eye which gives us an idea of a body exterior to us, exactly similar to touch; it is an impression made of a given figure. Every man might be able to see simply with every part of the body as well as with the eye; for if you were to place before my skin a refracting glass, so that the image should be thrown on my body of the same shape as that which is exterior, if my feeling was so very delicate as to distinguish this shape, it would give me the same idea as seeing. A drum has no sound in itself, but it has the power of putting the t matter of the air into action, which produces the idea of sound by its impression on the organ of hearing. The sense of touch would appear most to contradict the above statement; but touch only arises from the resistance of matter, which resistance alters the form of the part touching, and the alteration causes feeling. If it was the matter itself which caused the sensation, we ought to have as many kinds of matter as we have of sensation ; but our sensations correspond with the different properties of matter, not with the different kinds. But to return to my subject: by matter we mean all that composes this globe of the earth on which we live, and which is probably formed of only a few substances differing in specific pro- 12 HUNTER'S PRINCIPLES OF SURGERY. perties from each other, but which when compounded produce a very great variety, and of course these cause a great variety of sensations in us. Matter, thus compounded, appears to us in one of the three following states, a state of solidity, fluidity, or vapour. The first, or solidity, appears to be the natural state of matter; the other two seem to involve a kind of force, especially vapour. The first of the various properties of matter is attraction: of this there are many kinds, of which I shall first mention elective attraction, which is a disposition in all matter to unite with some particular kinds of matter rather than with others, forming with them a compound, which at the same time that it is a compound, seems homogeneous. Elective attraction can only take place when bodies are in a fluid state or in vapour; it would appear to be a kind of choice, and it is one of the most refined properties of common matter, producing new compounds by a species of generation, but annihilating the old by the same action. This property is given to matter for the purpose of forming various regular solids and fluids of which the world is composed, and it is this that gives us such variety. Secondly. By a particular attraction, or by an increase of the same attraction, these parts are brought into closer approximation: - this we call the attraction of cohesion, by means of which attraction bodies are kept in one mass. When bodies are so subdivided as to be reduced to their constituent particles, still each particle has its centre of gravity on which it may be said to move, from whence arises fluidity. So that a fluid would appear to be a body reduced to its original parts; the attraction of cohesion is destroyed, but v each particle has its centre of attraction or gravitation. As the centre of the globe attracts every particle of matter that is in it, so every mass of matter, simply as matter, has an attraction in its centre, by which it can bring bodies to it or keep them in contact with it. If we were to let drop some quicksilver, and it met with no resistance, it would assume a globular form : this is not from the attraction of cohesion, but from the attraction of gravitation. It must be observed, however, that where the attraction of cohesion is but slight, as in fluids, this will not take place, unless there is some affinity, as between acids and water, spirits of wine and water, &c. Water and oil will not unite by this species of attraction when in a fluid state. There are other general properties which arise out of the attraction of cohesion, such as figure, magnitude, &c. These properties are those which make bodies fit subjects for mechanics, but they are not the only ones necessary. A clock may be made correctly, but yet it will not go until we bring in some active power, such as gravitation, the raising of water into steam, &c. Thus we find something like the life of mechanics, which is not matter, but a property belonging to it; what is simply mechanical, that is made of inert matter, must have, as it were, a soul to put and continue it in motion. INTRODUCTION. 13 When all these properties have their full effect they produce various other effects, and become the regulators of the whole mass, confining its motion, space, &c. These are some of the properties of common matter. How far repulsion is a universal principle I am not able to determine; I should much suspect that it is not so general as the others. That there is such a principle in nature is evident, because neither fluidity nor vapour could take place without it; perhaps heat is the great repulsive property, at least it counteracts attraction and produces repulsion amongst the particles of matter when diffused through it. Thus the matter of the globe is in general so regulated, by properties stamped on it at first, that in its common actions it cannot err. But we find that matter has been carried much further in some other properties than in those just mentioned; it has undergone changes not in the least connected with or arising out of them, and its properties are of course entirely different; seeming, as it were, a monstrosity in the combination of matter. Its mode of continuance, by preparing within itself matter similar to itself, is entirely different. These changes produce the animal and vegetable or organic portion of the world.

Of the Matter of Animals and Vegetables.

Animal and vegetable matter has certainly arisen out of the matter of the globe, for we find it returning to it again. Both are subject to the laws mentioned above as regulating common matter, but they are so different, from their peculiar modification, as to appear at first like originally distinct species of matter ; but they will be found, on investigation, to be only a new modification of matter. This change in the original principles of matter seems to be equally distinct both in animal and vegetable matter, and the first principle of action of those two substances seems to be in great measure the same ; however, there are marks by which they can be distinguished. The connexion of these two modifications of matter with common matter has never yet been traced, nor has the gradual transition from one to the other been imagined ; and if those substances had not reverted into common matter by their decomposition, it never could have been suspected that they were originally composed of the same materials. For these reasons they have been ranked by themselves. Animal and vegetable substances differ from common matter in having a power superadded, totally different from any other known property of matter, out of which arise various new properties. Animals and vegetables have a power of action within themselves, are capable of increasing their own magnitude, and possess 2 14 HUNTER'S PRINCIPLES OF SURGERY. the power, as it were, of working themselves into form and a highei state of existence. This power of action and capability of increase requires a supply of, materials, as well for the increase as for the waste arising from action. This supply appears not to be wholly the same in both, though perhaps it may be. The idea of a supply always supposes a resource distinct from the thing supplied, and no waste parts can ever perfectly revert into the thing itself without first going through all the changes which first brought it into a fit state. This supply is furnished by the materials of the globe. Vegetables alone appear to have a power of immediately converting common matter into their own kind. Animals probably have not that power, therefore are removed further from common matter; so that a vegetable seems an intermediate step between common matter and animal matter. But observation will show that vegetables can readily convert both animal and vegetable matter into their own substance, as in the case of dung, which increases the natural growth of plants.* Both have a power in propagating their kinds by a production out of themselves, by which means the stock is replenished. Both are capable of being in two states: one of these is the living state, which wre have been considering, the other is the dead state. Hence both animals and vegetables are capable of being considered in three ways. 1st, In their power of continuance and production, when possessed of their natural powers of action or life. 2d, In their nature chemically as matter, which can only be considered when they are dead. 3d, In their decay, or spontaneous reduction to common matter, when life is gone.f In all these operations they are totally different from common matter.

* [It is highly probable that the different proximate elements of vegetable and animal substances hold different ranks in the scale of organised substances, in the same manner that one animal ranks higher in the scale of organised beings than another. Thus, starch, sugar, and woody fibre among vegetable substances, and gelatin, albumen, and fibrin among animal substances, are raised, as it were, from one to the other by successive processes in the animal or vegetable economy ; so that fibrin may be regarded as the substance most hiorhly animalized, or as possessing the distinctive properties of an animal substance in the highest possible degree. In this view, vegetable life, which subsists almost exclusively on carbonic acid gas, and graminivorous animals, which are able to extract nutriment from vegetable substances, may be regarded as subservient processes, intended to prepare the common elements of matter as nutriment for the more perfect animals,—which, however, afterwards undergoes a series of further processes in the bodies of these animals, in order to fit it for all the purposes of the economy. Sennebier and Saussure have satisfactorily shown that decayed organic remains do not nourish plants by being absorbed in their unmodified state, but by affording a more abundant supply of carbonic acid gas, which, in combination with water, forms the principal aliment of vegetables. There is no process in vegetables corresponding to digestion in animals, and hence the food of plants is spontaneously evolved by the natural processes of fermentation and putrefaction.] | [There are many other distinctions between organised and inorganised bodies, which, however, it is unnecessary to consider in this place.] INTRODUCTION. 15 The first distinction, or life, in which consists the power of selfpreservation, is the antidote to the two last, since before either of these can utke place the whole part must be deprived of the living principle. When in the first state, their actions are either natural, the whole being in harmony, and every part acting in concert with the rest, which is called health; or they are unnatural, which constitutes disease, the tendency of which is to destroy the whole. When chemically considered, both animal and vegetable matter are found to be acted on by different substances, or are capable of solution in other bodies, as concentrated acids, alkalies, &c, in which respect they are pretty similar to one another. Both are capable of being acted on by fire; but in this process we find each yielding some substances peculiar to itself;—animal matter when distilled yields water, volatile alkali, empyreumatic oil, and calcareous earth;—besides these there is a small proportion of iron, which does not appear, however, to be a constituent part of the whole animal body, being chiefly procurable from the blood ; a small proportion of their substances may also be found in the blood.* In their decay, both animals and vegetables go through a series of regular spontaneous changes, the succeeding one arising entirely out of the first, and the next out of this, until the whole return to common matter from whence they arose, for to the earth they must return from whence they came. In this natural process we find animals and vegetables yield many substances not to be found in them before these changes, also not to be found in common matter. This process I call fermentation, and it is peculiar, I believe, to vegetable and animal matter. The processes carried on by chemistry and fermentation, which can only take place when the parts are dead, have been introduced by physiologists into the living animal economy; and, not satisfied with this, they have brought in mechanics to account for many of the operations of vegetables and animals. But, for the purpose of distinguishing more accurately between mechanical, chemical, and vital operations, and the circumstances under which the two first are applied to the living body, let us consider them a little further. The actions and productions of actions, both in vegetable and animal bodies, have been hitherto considered so much under the prepossessions of chemical and mechanical philosophy, that physiologists have entirely lost sight of life; and perhaps they have

* [Vegetable substances are nearly all composed of oxygen, hydrogen, and carbon,—carbon, for the most part, being the preponderating ingredient. In some few examples nitrogen is likewise present. The proximate principles of vegetables, or those substances which exist ready formed in plants, are exceed. ingly numerous, as gum, starch, sugar, &c, amounting in the whole to not less than forty-five or fifty substances, characterised by different properties. Animal substances, on the contrary, at least all the principal animal substances, contain nitrogen as well as oxygen, hydrogen, and carbon, and the proximate elements are not so numerous as those of vegetables. The animal fats, which are considered by many as a natural store of nutriment, contain no nitrogen, and therefore approximate to vegetable products.] 16 HUNTER'S PRINCIPLES OF SURGERY.

been led to this mode of reasoning because these properties are much more familiar, more adapted to our understandings, and more demonstrable than the living properties of organized beings. But unless we consider life as the immediate cause of all actions occurring either in animals or vegetables, we can have no just conception of either vegetable or animal matter. No wonder, then, that the theories of the older physiologists are ill built and ill supported, their principles being false. Many of the effects both in animals and vegetables might at first sight appear to be chemical, or the consequence of fermentation. The production of many juices of plants, such as gums, acids, sugar, &c, would seem to be of this kind ; but all arise from natural actions of the vegetable, and do not belong to chemistry. No chemist on earth can make out of the earth a piece of sugar, but a vegetable can do it. Digestion, the formation of the blood, and all the secretions of an animal, might at first appear to be of this sort; but that they really are not chemical products I am clearly convinced. If an ingenious man undertook to account for every change in matter by fermentation, there is no change in nature that might not be brought within his definition. The living principle itself would be shown to arise from fermentation ; brain, muscles, bones would grow from fermentation, since they are all formed from the blood, and yet the blood is not found in them.-—Of all things on the face of the earth definitions are the most cursed; for if you make a definition you may bring together under it a thousand things that have not the least connexion with it.*

* [By the fermentation here spoken of is not meant that process of spontaneous decomposition, occurring under the conditions of heat and moisture, to which the appellation is restricted by modern chemists, but a vague chemical disturbance, in the course of which a new and undefined arrangement of the elements was imagined to take place. Mr. Hunter, in his zeal for the vital principle, has probably gone too far in excluding the agency of chemical causes. There is not the leasf reason for supposing that the vital principle is able to confer new properties on matter, or to transmute one matter into another, so as indiscriminately to employ other substances thau those which it does for the repair of the body and its various secretions ; on the contrary, there seems every reason for believing that the elementary particles exert the same affinities under the influence of vitality that they do in the laboratory of the chemist, and that if it were possible to present these to each other out of the body under precisely the same circumstances that they are presented in the body, and in the requisite states and proportions, the same combinations would take place, and the same results would be produced. The vital principle may not perhaps improperly be compared to the principles of heat and electricity, which exert an influence over the affinities of matter without essentially altering its nature; but the great distinction between organic and ordinary chemistry is not less in the nature of the agent than in the minute and appropriate apparatus by which that agent operates. All the processes of organic life, referrible to this head, are executed, as it were anatomically, by an arrangement of parts infinitely small; by which the affinities of the acting bodies are brought together in modes which cannot artificially be imitated by the chemist. The following observations by the reviewer of MM. Tiedemann and Gmelin's Treatise on Digestion apply to the present question :__" Je suis loin de nier qu'il y ait dans les actes du corps vivans quelque ohose de special, INTRODUCTION. 17 What I call fermentation, only takes place in animal and vegetable matter when dead. It is that change which takes place in the substances themselves out of their own spontaneity, without any external assistance. Chemistry is a kind of force on things to decompose them. In the process of fermentation, vegetable matter goes through intermediate stages, in which it is neither vegetable nor common matter; the same with animal matter during putrefaction. But in all the productions of a living animal or vegetable, the substances produced are animal or vegetable matter. The only substance produced in an animal which cannot be called animal matter is the earthy matter of bones, and of some diseased parts :* it appears also that, in some of the secretions of animals, the products produced have none of the original properties of animal matter, as the sugar of milk, the bitter principle in the bile, these not having been found in any of the natural solids or fluids by any process whatever. But this does not come up to my notion of fermentation, for no process of fermentation of animal or vegetable matter ever produced either one or the other ; and even in vegetables, where sugar seems to constitute part of the plant, it is formed by the action of the vegetable. If ever any matter is formed in any of the juices secreted in any part of a vegetable or animal body similar to what arises from fermentation, we may depend on it it arose from that process, but we may also depend on it that there is a defect of the living principle in those cases. The conversion of water into vegetables, which is vegetation, or of vegetable and animal matter into animals, which is animalization, is not a change taking place according to the nature of the substance, but is effected by the actions of the vegetable or animaj. The different juices formed from the blood, called secretions, differ not from the nature of the blood as animal matter, all giving nearly the same substances when analysed, or subjected to fermentation. Nor can the substances formed in a vegetable be formed, by any process that we know of, from water.f We might suppose that fermentation would produce an animal from a vegetable, because in this change " a decomposition of matter and a new combination" is effected; but fermentation never could bring back dead animal or vegetable matter to living, so that it does not correspond to the

quelque chose qui reconnait d'autres lois que celles qui regissent les corps bruts ; mais ces dernieres interviennent, sans aucun doute, plus qu'on ne le pense generalement dans les functions de nutrition ; et c'est mieux servir la science de la vie de reconnaitre cet intervention, et de l'etudier jusqu'a son extreme limite que devoir partout de la vitalite sans attacher a ce mot un veritable sens."] * [It is a question with some geologists whether lime is not essentially an animal product.] f [The refinements even of modern chemistry have not yet enabled us to form any animal or vegetable principle ab origine from any combination of the ultimate elements. The substance called oxalamide, obtained by Professor Faraday from the oxalate of ammonia, approaches in character to an animal product, although it is not actually so. A few other examples of the same sort might be mentioned.] 2* 18 HUNTER'S PRINCIPLES OF SURGERY. above definition which has been given of it. This single circumstance throws more light on the power of the stomach than we are yet aware of, for dead matter subjected to it is not obliged to undergo any change as matter, but goes through that process which produces life.* In treating of an animal body I shall always consider its operations, or the causes of all its effects, as arising from the principle of life, and lay it down as a rule that no chemical or mechanical property can become the first cause of any of the effects in the machine. But as all animals have form and motion, which motion is directed by that form, these motions become mechanical, so that every motion may be truly called mechanical. Mechanics are therefore introduced into the machine for many purposes. The living principle, however, in itself is not in the least mechanical, neither does it arise from, nor is it in the least connected with, any mechanical principle. Having thus given a general idea of these singular combinations of matter, I shall now confine myself to animal matter. But before I treat of the diseases of the animal body, which is the intention of these lectures, it will be necessary to give such general ideas of the subject, and to lay down such axioms and propositions, as will enable you to follow me through all the necessary descriptions of preternatural actions of the machine. This matter we must consider in two points of view: 1st, in its production; 2dly, in its continuance. This leads me into a new field, and exhibits properties very different from all the other properties of matter. It will be necessary,.I say, to have clear and distinct ideas of the difference between animate and inanimate matter, in order to know when and where the animal principle acts, and when other principles are made use of in an animal body in accomplishing all the different purposes of life. The human body is what I mean chiefly to treat of; but 1 shall often find it necessary to illustrate some of the propositions which I shall lay down from animals of an inferior order, in whom the principles may be more distinct and less blended with others, or where the parts are differently constructed, in order to show from

* [There are grounds, I think, for believing that the first rudiments of life, or the revivication of dead animal matter, actually commences in the stomach.— Digestion, however, is a complicated chemical process, and not of that simple kind that might be inferred from Mr. Hunter's language. (See Tiedemann and Gmelin, and Prout.) The transformation or passage of common matter under the empire of physical laws to living matter which exists in defiance of those laws, is a mystery which will perhaps never be completely understood. So fat as observation has gone, the steps of this transformation are gradual and complicated; the products of each successive process always advancing from a lower to a higher degree of animalization. If therefore we regard life as a superadded principle, we cannot but observe that it is communicated to common matter only in proportion as this matter is animalized. In short, certain conditions of the recipients of life seem necessary before it can be communicated, and the higher the manifestations of life the higher are these conditions. The manifestation of intellect in proportion to the development of the brain presents an example very analogous.] ON THE VITAL PRINCIPLE. 19 many varieties of structure, and from many different considerations, what are the uses of the same parts in man; or at least to show that they are not for the uses which have been commonly assigned to them; and as man is the most complicated part of the whole animal creation, it will be proper in the first place to point out general principles common to all this species of matter, that I may be better understood when 1 come to the more complicated machine, namely, the human. Besides having recourse to many of the inferior orders of animals for the elucidation of some of the phenomena of the more complicated orders, we are also obliged to Disease for many of our hints on the animal economy, or for explaining the actions of parts, for the wrong action of a part often points out what the natural action was, and itself gives an idea of life. Disease often corrects our imagination and opinions, and shows us that such and such parts cannot have the uses commonly attributed to them, and therefore brings us a step towards the knowledge of the true use. Monstrosities contribute to rectify our opinions in the same if not in a more intelligible manner. A monster is either from a deficiency of parts which cajj^be produced from art (and often is from necessity, as in operations), or else from a modification caused by a wrong arrangement or construction of parts, which will produce an unnatural action, by which means the natural action may be known. CHAPTER II.

Difficulty of conceiving of this principle ;—complex in its effects, but simple in it3 essence; not the result of any perceptible arrangement of matter;—may result from a peculiar arrangement of the ultimate particles, giving rise to a principle of preservation;—this the simplest idea of life;—illustrated by magnetism in iron.—Erroneous comparison of life to mechanical powers.— Action not an essential property of life.—Life without action;—vitality of an egg;—experiments;—but action promotes the continuance of life.—Seeming exceptions to the preservative power of life;—peculiar form of putrefaction in certain bodies; death of a part of the body previously to general death.

Animal matter is endowed with a principle called, in common language, life. This principle is, perhaps, conceived of with more difficulty than any other in nature, which arises from its being more complex in its effects than any other; and it is therefore no wonder that it is the least understood. But although life may appear very compounded in its effects in a complicated animal like man, it is as simple in him as in the most simple animal, and is reducible to one simple property in every animal.*

* [It is considered by many, and perhaps truly, that we are not yet prepared for a generalization of so high a kind, or at least that it would be more convenient for the analysis of vital phenomena to consider life as made up of several principles differing in their nature.] 20 HUNTER'S PRINCIPLES OF SURGERY. I have observed that animal matter may be in two states; in one it is endowed with the living principle, in the other it is deprived of it. From this it appears that the principle called life cannot arise from the peculiar modification of matter, because the same modification exists where this principle is no more. The matter abstracted from life appears at all times to be the same, as far as our senses and experiments carry us. If life arose out of this peculiar modification, it would not be destroyed until the modification was destroyed, either by spontaneous changes, as fermentation, or by some chemical processes ; and were it destroyed by the last, it might sometimes be restored again by another process. Life, then, appears to be something superadded to this peculiar modification of matter; or this modification of matter is so arranged that the principle of life arises out of the arrangement, and this peculiar disposition of parts may be destroyed, and still the modification, from which it is called animal matter, remain the same. If the latter be the true explanation, this arrangement of parts, on which life should depend, would not be that position of parts necessary to the formation of a whole part or organ, for that is probably a mechanical, or at least organical, arrangement, but just a peculiar arrangement of the most simple particles, giving rise to a principle of preservation; so that matter so arranged could not undergo any destructive change till this arrangement were destroyed, which is death. This simple principle of life can with difficulty be conceived ; but to show that matter may take on new properties without being altered in itself as to the species of matter, it may be not improper to illustrate this idea by such acquirements in other matter. Perhaps magnetism affords us the best illustration we can give of this. Iron appears at all times the same, whether endued with this property or not; magnetism does not seem to depend on the formation of any of its parts. A bar of iron without magnetism may be considered like animal matter without life; set it upright and it acquires a new property, of attraction and repulsion, at its different ends. Now is this any substance added; or is it a certain change which takes place in the arrangement of the particles of iron giving it this property ? If we take a piece of glass, it is transparent; we break it into a thousand pieces and it becomes white. Whiteness is not a new matter added to it, but a property arising from its being composed of a number of small pieces. It was not sufficient that animal matter should be endowed with this first principle, the principle of preservation, it was necessary that it should have action or motion within itself. This does not necessarily arise out of the arrangement for preservation; on the other hand, the arrangement for preservation, which is life, becomes the principle of action, not the power of action, for the power of action is one step further. The power of action must arise from a particular position of those living parts, for before action can take place the matter must be arranged with this view. This is o-enerally effected by the union of two or more living parts, so united as to ON THE VITAL PRINCIPLE, 21 allow of motion on each other, Which motion the principle of action is capable of effecting when so disposed. A number of these simple acting parts, united, make a muscular fibre; when a number of these are put together they form a muscle, which, joined with other kinds of animal matter, as tendon, ligament, composes what may be called an organ. Thus, too, by the arrangement of the living particles, the other organs of the body are formed, their various dispositions and actions depending on the nature of the arrangement, for action is not confined to muscle, the nerves also have action arising from the arrangement of their living particles.* The principle of life has been compared to the spring of a watch, or the moving powers of other machinery; but its mode of existence is entirely different. In a machine the power is only the cause of the first action or movement, and thereby becomes the remote cause of the second, third, &c.; but this is not the case with an animal; animal matter has a principle of action in every part, independent of the others, and whenever the action of one part (which is always the effect of the living principle,) becomes the cause of an action in another, it is by stimulating the living principle of that other part, the action in the second part being as much the effect of the living principle of that part as the action of the first was of the living principle in it. The living principle, then, is the immediate cause of action in every part; it is therefore essential to every part, and is as much the property of it as gravity is of every particle of matter composing the whole. Every individual particle of the animal matter, then, is possessed of life, and the least imaginable part which we can separate is as much alive as the whole. The first, and most simple idea of life, I have observed, is its being the principle of self-preservation, preventing matter from falling into dissolution,—for dissolution immediately takes place when matter is deprived of it; and the second is its being the principle of action. These are two very different properties, though arising from the same principle, the first being capable of existing independently of the second; for it may be observed, that it is not necessary for the preservation of animal matter that there should be action in all parts, for many parts of an animal appear to have

* [This opinion concerning the unity of the principle of life has already been shortly adverted to. It may perhaps be illustrated by referring to the powers of common matter, which are not one, but many. There seems good reason for considering the different kinds of attraction as modifications of a higher principle, and the best reason for believing that magnetism, common electricity, and galvanism proceed from the same source, or at least are essentially identical; the same is highly probable in regard to the powers of life; in analysing physical phenomena, however, it is found far more convenient to consider the powers above mentioned separately, and it cannot be doubted that physiologists would derive equal advantage from pursuing a similar method. According to the author's representation, the modifications of life result simply from differences in the organised apparatus, through which it manifests its effects, nearly in the same way as mechanical force may be made to produce the most different effects, according to the kind of machinery which is employed.] 22 HUNTER'S PRINCIPLES OF SURGERY. little action, yet they are as much endued with life as the more active parts; such, for instance, as tendons, elastic ligaments, &c. A fresh egg is a body which, it must be allowed, has no vital action; yet an egg is as much alive as an animal, which I shall endeavour to illustrate by observation and experiment. I was led to this opinion in the year 1757, when I was making drawings of the growth of the chick in the process of incubation. I then observed, that whenever an egg was hatched, the yolk, which is not diminished in the term of incubation, remains sweet to the last, and that part of the albumen which was not employed in the growth of the chick was perfectly sweet some days before the hatching, though both had been kept at a temperature of 103° in a hen's nest for three weeks. But if the egg did not hatch, I observed that it became putrid nearly in the same time that other dead animal matter does. To determine how far eggs would stand other tests of the presence of the living principle, I made the following experiments: I put an egg into a freezing mixture about zero, and froze it, and then allowed it to thaw. From this process I conceived that the preserving power of the egg must be lost, which proved the case. I then put the egg into a freezing mixture at 15°, and with it a newlaid one, to make the comparison on that which I should call alive, and the difference in the time of freezing was seven minutes and a half, the second one taking so much longer to freeze. 2d. I put a new-laid egg into a cold between 17° and 15°; it took about half an hour to freeze: when thawed I put it into an atmosphere only at 25°; it froze in half the time, which it should not have done, nor even in half an hour, if had not been killed by the first experiment, for the atmosphere now was not so cold as in the first experiment by nine degrees. These experiments show that the egg, when living, has a power of resisting cold, which, when killed by freezing, it has not. To determine the comparative heat of a living and dead egg, and to determine whether a living egg be subject to the same laws with the more imperfect animals, I made the following experiment. I took a fresh egg, and one which had been frozen, and put them into a cold mixture at 15°. The thawed one soon came down to 32°, began to swell and congeal: the fresh one sunk to 29£°, as happens to living animals, and in twenty-five minutes after the dead one froze. Another reason for supposing it dead was, that before freezing took place it rose to 32°, as other fluids do which are brought below their freezing point. From these observations and experiments, it must appear that a fresh egg has a power of resisting heat, cold, and putrefaction; and similar results are come to by similar experiments on some of the more imperfect animals, which we shall have occasion to notice hereafter. It would appear, then, that life is hot action, but it is continued or supported by it when it takes place. Action creates a necessity of ON THE VITAL PRINCIPLE. 23 support, and furnishes it. It is not necessary that action should continue in all parts ; in some it is only necessary that the principle and power of action should be continued, but in others it is necessary that action should take place even for the preservation of the principle of action. Action is necessary for the various purposes for which the animal is intended, and if one species of action takes place, it brings the whole into action, as all the parts and actions of an animal body are dependent upon one another. If the heart acts, the lungs must fulfil their part; the stomach must digest, the other parts subservient to this organ must be put in motion, and the secretory organs, nerves, and voluntary muscles. The whole is thus set in motion to produce some ultimate effect, which appears to be the propagation of the species, for preservation (of the individual) cannot be called the ultimate effect. I have asserted that life simply is the principle of preservation in the animal preserving it from putrefaction; but there is a curious circumstance attending life which would appear to be contradictory to itself. Life is the preserver of the body from putrefaction, and when life is gone putrefaction would appear soon to begin. But this is not uniform ; it is sooner in some cases than in others; therefore there must be some other cause than the simple deprivation of life to account for this difference of time. In the most striking instances of rapid putrefaction after death, it does not appear to arise from the process of putrefaction having gone to some length before total death took place, for in those who die of putrid fever the smell becomes less offensive before death, and when life is gone they do not go into putrefaction as soon as might have been expected, and not nearly so fast as many who had not the least tendency this way before death. The tendency to putrefaction in those whilst living would appear to be part of the disease, but does not become putrefaction, and on dying they appear to lose that tendency, and to become like other bodies. However, it is disputed whether, in putrid fever, there is really any putrid matter formed.* But there is a process or an action in life which predisposes the body for many diseases, and which becomes the remote cause of them ; and there is an action in life which disposes the body for a species of putrefaction (or decomposition) when dead, and very probably death is the effect of this action in these cases. In these cases the body immediately after death becomes emphysematous; this emphysema, though it does not occur during life, would yet appear to be an effect of life, for it depends on disease as the body is dying. It is not genuine putrefaction; for, when the process is ended, the body keeps nearly as long as if no such process had taken place. It occurs immediately after death, or perhaps in the act of dying. The process itself seems to continue when the body * [The offensive exhalations here alluded to may probably, in great part, be referred to the excretions, which show a great tendency to run into rapid decomposition.] 24 HUNTER'S PRINCIPLES OF SURGERY.

is warm; after a time it stops, and the body remains stationary, until it sets out, as it were, for a second time to become putrid. What diseases this is to be classed with I do not know. To ascertain the causes of it with precision, it would be necessary to know the persons when alive, the disease of which they died, and the time when the putrefaction occurred after death. I have myself seen several very remarkable instances of its occurrence. The first was that of a young lady about four months gone with child, who in March or April, about two or three in the afternoon, was suddenly taken ill with a fit, of which she shortly died. She was opened the next morning at seven o'clock, when the body was found swelled with air extravasated in the cellular membrane; the mesentery, intestines, liver, and heart were loaded with air, the blood worked out of the larger vessels mixed with air, and the body had become very offensive. Another case of the kind occurred at St. George's Hospital, in a man who had an encysted tumour in the upper belly of the right rectus muscle, which contained a fluid: it was opened on Friday, and on the Monday following, in the evening, he became ill, and died at one o'clock. He was opened seventeen hours after death, and was found emphysematous, just as in the former case. This appears to be similar to what is commonly termed sphacelus, being a species of mortification occurring before death, or in the act of dying. That the mode of dying assists the process of putrefaction is evident in common mortification, which will be noticed when on that subject, and I may illustrate it further by relating what took place in a case of operation for aneurism. A man at St. George's Hospital had the operation for popliteal aneurism performed. The artery was tied just where it passes through the tendon of the triceps muscle. The case went on well till the sixth day, when ulceration took place in some part of the artery which was not united: considerable bleeding took place, and recurred several times afterwards, by which so much blood was lost as to become in the end the cause of death. Immediately after the first bleeding, I observed the foot and leg of the diseased side to become cold as high as the middle of the calf, while it was warm about the knee, ham, and upper part of the leg. The lower part of this leg ever after remained cold, and did not in the least change in appearance, from which I conjectured that it was dead, not mortified (for there is a material difference). I suspected it was dead as in common death. He became wreaker and weaker every day, and died about four days after. Before he died, the upper parts of the leg, which had gone on with life a little longer, were mortified, that is, they showed evident signs of such a change taking place; a vesication formed, discharging a bloody serum, and they became darker, as if blood was diffused in the cellular membrane, and oedematous, or, rather, emphysematous. A very short time after death these parts became putrid, while the lower part of ON THE VITAL PRINCIPLE. 25 the leg and foot remained unaltered as in common death. Here was a part which just died for want of circulation, therefore no action took place in that part; but above, where there was action, a very different change took place, producing a tendency to putrefaction after total death had taken place. The part which died naturally without any action did not become putrid, while the part in which that peculiar action took place became putrid directly, though it died later. I took off the two feet, to see which of them would become putrid first; for some time it was difficult to perceive any difference, but about sixteen days after, the foot on the sound side began to turn green, and went on to putrefy much faster than the other. The whole of this part of the case is extremely curious. First, that part of the leg which retained life longest became putrid immediately after death, because during life it took on actions which were productive of putrefaction. The foot of the diseased side, which died early, was not allowed time to take on any actions while living, excepting perhaps that resulting from the stimulus of death, and did not become putrid so soon as the foot on the sound side, which may be said to have died a natural death, and w7hich died later. This I think may be accounted for by supposing that the latter, from surviving some time longer, took on some of those actions which gave the tendency to putrefaction. It may be necessary to explain what I mean by the stimulus of death. Death itself produces an action in all the muscular parts when there is nothing to prevent it. If a man's head be cut off, he becomes stiff; he is not stiff while there is real life: for there is a difference between visible life and real life. A part may be living though not in action; but whenever death takes place it excites an action in every part that is muscular: they contract, and this is the action of death. To cease breathing is not the action of death, though certainly it is the first step towards it, and gives rise to the other. The action of real death is that which takes place in the stiffening of the body, and till then it is not dead (except when killed in a peculiar manner—killed universally before the stimulus of death can be given,— and then it remains lax). I suppose, then, that this foot, which died first from the loss of blood, became stiff; that is, took an action resulting from the stimulus of death, all the muscular parts contracting;—that in the other foot the stimulus of death was in some measure lost, from the longer continuance of the diseased state, and the consequent action was less strong. What would be the consequence of this 1 I take a man in perfect health, and cut off both his legs; to one I give a stroke of electricity sufficient to kill the part before it contracts, and no contraction takes place; the other I leave to itself and let the stimulus of death produce contraction: this latter shall not become putrid so rapidly as the former. 3 26 HUNTER'S PRINCIPLES OF SURGERY. CHAPTER III.

Reasons for its fluidity;—erroneous views respecting its nature.—Animalization and vivification two distinct steps in the conversion of foreign matter into part of a living body.—Blood not merely fluid animal matter;—has also become vivified;—arguments for this opinion.—Coagulation of blood;—its importance in determining the nature of blood;—varieties in the process.— Case proving the life of the blood.—Death of the blood preventing coagulation.

What I have had hitherto principally in view has been the solid animal matter, its formation, and its arrangement by which it is endued with life, composing, as it were, the whole visible body. The fluid part of the compound now remains to be taken notice of. Blood is the material out of which the whole body is formed and out of which it is supported.* It is fluid that it may be capable of moving to the very minutest part of the solid with ease, and may with less difficulty be divided for the increase and repairs of the different parts of the machine; easy of division and separation, to form various secretions, and also to bring back what was superabundant, and to carry off the parts which were useless. This part of the body has been considered as a passive, inanimate, moving fluid, found everywhere in the body, deriving motion from the heart for the various purposes of the whole, then returning to the heart to be sent out again. Those who have formed this idea of the blood have no adequate notion of the manner in which it is capable of performing those great uses above mentioned. Some, in considering this fluid, have been in a great measure satisfied with examining the spontaneous changes which it undergoes out of the circulation. This might have led them to draw some natural conclusions, since all natural phenomena are facts, and teach enough of a thing to enable us to draw sound conclusions. Others have attended to the chemical analysis, which teaches nothing with respect to its use in the living body; for blood gives no analysis excepting that of common animal matter.t Some inquirers have laid great stress on its appearance when viewed with a microscope, as if forms of parts would explain first principles: this they cannot do unless in operations that are mechanical. This inquiry could * [The expression of Bordeu is peculiarly elegant: " Lt sang est de la chair coulante.,,'\ ■j- [This observations no longer true. Some important additions to physiology have of late years been obtained from chemical investigation of the blood with the present improved means of analysis; and <with further improvements we may expect still more light to be thrown on the subject. The subject will be more fully considered when the 'Treatise on the Blood,' &c, comes before us.] THE BLOOD. 27 be carried no further than to investigate such parts of the blood as have form and opacity, if there are such, and that which appears to have both is called red blood: in a great number of animals, therefore, the knowledge of the operations of the blood in the animal body rests nearly in the same state that it did some centuries ago. The two last points of investigation, namely, the chemical analysis of the blood and the form of the blood globules, though very proper to be made by physiologists, have hitherto explained nothing in the animal economy. Before I explain my opinion of the blood, it may not be improper first to state some facts from which I draw my conclusions. I have endeavoured to show that animal matter differs from common matter in many circumstances ; that this animal matter has a principle peculiar to itself, which I call life, and this life is the second step or process of animal matter. Animalization is the first; vivification the second. To prove this, I observed that an animal is increased and supported by many substances, which previously had not the properties of animal matter, and of course not the principle called animal life; I observed, too, that it was also supported by substances which were of animal origin, but which had not then the living principle; in other wrords, an animal can be supported on dead vegetable and animal matter. In the next place it was remarked that these substances, before they can increase or support the animal, must all be converted into animal matter; and lastly, that the substances must be so prepared, or animalized, as to become part of the body, and of course to be endued with the living principle. It is now necessary to trace these changes in the food till it becomes part of our solids, rand observe as we go along when it is most probable that life begins. Blood is not simply fluid animal matter, it is animal matter particularly arranged, for it differs in every respect from fluid animal matter produced by art. The first change that takes place with vegetable matter before it is rendered blood is its conversion into animal matter. This change I call animalization. With animal matter it might be supposed that no change wras necessary to produce animalization ; but we find the change, whatever it may be, the same in both; and the process in both is probably similar, for the produce from the digestion of animal matter is as different from common animal matter as anything can be: were it not so, animal substances rendered fluid by chemical operations, as jellies, &c, would answer the same purpose as blood. But the necessity for a total and similar change in both is evident, for out of this change life is to arise, digestion being the first step towards vivification. It may be supposed that the first step in the digestion of vegetables is that of animalizing them, and that they go through the next of chylification with animal matter; but this we cannot allow, for it would be supposing two different actions going on in the stomach St the same time, which I should very much doubt. 28 HUNTER'S PRINCIPLES OF SURGERY.

The second process, vivification, must take place somewhere before the blood becomes an active part of the machine. We shall first premise that animalization may take place without vivification, —(how far this is the case is not easily determined,)—however, we may say with certainty that vivification cannot be prior to animalization. Let us first trace animalization. Animalization begins in the stomach, and in common language is called digestion, the immediate produce of which is called chyle. In the change of food into chyle we do not see why it may not have received the living principle, for the change is such as renders it capable of becoming alive. But it may be supposed that this process is reserved for the lungs, where the chyle is so much exposed to the air : the air may be imagined to act on it like heat on an egg, or moisture and warmth on seeds, giving a power of growth to their particles. In these cases, however, it is not the principle of life which they give ; they only give life its action. Again, blood may be supposed not to become alive till it be made into a solid, when it becomes part of our body, and loses the property of blood, and there its life is indisputable; but I am apt to believe that the living principle takes place sooner, which I imagine will appear in investigating the properties of the blood, with the many phenomena that attend it in the living body. I have already observed that the organization of animal matter is not necessary for life,^ only for its actions ; therefore fluidity is no objection to the blood being alive. My reasons for supposing the blood to be alive in a fluid state are the following: 1st, It may be observed that it appears to carry life to every part of the body, for whenever the whole or a part is deprived of fresh blood it very soon dies. This blood, however, must be such as has undergone some change in the lungs; for if the blood did not undergo this change it would probably soon die, therefore would not be capable of keeping up the living principle in other parts. This effect arising from the want of fresh blood is so evident that it needs no illustration; I may therefore conclude that it is the only cause and | support of life, the nerves having no other part in it but to produce some of the actions,—not life itself, for without this support the nerves themselves die, 2dly, We may observe that whilst circulating, or in useful motion, it is always found in a fluid state.— Hence I think I may be allowed to say, as it is never found in a solid form in the cavity of the blood-vessels, that it has not the least tendency to become solid; that such a state is contrary to its nature.

* [This has ever been a quxstio vexata with physiologists, and will Dro- SJrFn.Tf'VrM S°a T-\inStanCe °f thf eS- which has be*n already adduced, and of the blood, which now comes under consideration, were supposed by Mr. Hunter to demonstrate the existence of vitality independently of organization. Although, however, the fact of the vitality of the blood and of the!w should be admitted, it yet remains to be proved that the globules of which thev both appear to consist do not present incipient traces of organization • hut the question is not one which can be entered into here.] «»«««» »«« THE BLOOD. 29 This must arise from some principle which is probably both in the blood and the vessel. The want of disposition to coagulate whilst moving in the living vessel does not arise from the motion, for in many places where the motion is extremely slow the blood remains fluid. We have instances of this in the veins of the leg, where the crural arterv has been tied, in which case the blood only moves through a few small collateral branches below, and back again by the larger veins. Now, a small quantity of blood being sent into these larger vessels, the motion in them must be next to stagnation; yet, while there is any degree of motion, the irritation of imperfection is not given: there is consciousness of its being an useful part; by which is meant that the harmony between • the solids and fluids is kept up. It is curious often to see the small , quantity of motion which shall keep up this mutual harmony. In cases where people have been days, or even weeks, in trances, where there is not the least perceptible motion in the blood, it has retained its fluidity, because both solids and fluids retained their life, though not their actions. The want of disposition to coagulate in such situations does not arise from any property in the blood simply as animal matter, for simply as animal matter (whose alterations arise out of its composition, as fermentation,) it would not va^ in its effects from circumstances that do not in the least alter the nature of the compound. Dead animal matter acts on the living body as any other foreign or extraneous matter ; therefore, the blood being in perfect harmony , with the living principles of the solids when both are in perfect health, is a presumption that the blood is alive. However, this argument is not conclusive, for we find in the blood heterogeneous parts which do not destroy this harmony: most probably those heterogeneous bodies are introduced simply as stimulants to the living principle, as extraneous objects are to the sensitive. This harmony of the blood with the solids is more observable in some parts than others. The parts with which it is in the greatest " harmony are the vessels ; this is evident from its retaining its fluidity longer in contact with them without motion than in any other part of the body, though equally inclosed in living parts. All the diseases which act on the solids act on the blood, causing it to effect those changes which arise spontaneously from rest out i of the .body; so that blood is as capable of diseased actions as the solids are. If the blood did not change in the diseased states of the solids, it would lose the natural harmony I have been speaking of. This change is according to the state of the solids, which shows the intimate connexion between the two; it is not primary diseased alteration of the fluids, but a consent with the diseased disposition of the solids.*

* [How far the blood can originate an action within itself, for the purpose, as it were, of bringing itself into harmony with the changed condition of the solids is a aaestion which I think will generally be answered in the negative. That tie blood does harmonize with the solids is an incontestible fact; but then the 3* 30 HUNTER'S PRINCIPLES OF SURGERY. On the other hand, the solids are affected by diseases of the blood : I even suspect death in the blood can take place independently of the solids; but the death of the solids will soon follow. The blood when at rest has a disposition to separate into several parts, viz. coagulable lymph, red particles, and serum; the red part being retained in the coagulable matter, and the serum squeezed out in the act of coagulation. This disposition in one of the parts to coagulate when at rest, from whence the above changes are produced, is more or less strong, according to circumstances. This property of the blood deserves particular attention, as it throws more light on its nature than any point of view in which it can be considered, it being spontaneous and natural. It is by this change that the solids are formed, and it seems to me so important that I think it almost the only thing necessary to be considered more fully; indeed the power of coagulation in the blood throws so much light on the nature of a disease, so far as the blood is concerned, that it is almost the only part we have recourse to in the examination of the blood after bleeding, when we look to see whether or not the blood is buffy, that is, whether there has been a disposition for the red globules to sink faster in such blood; or rather, perhaps, that from such blood being longer in coagulating, the red globules have time to sink to the bottom, and leave the coagultble lymph atop free from red globules, and this causes the buff' of the blood.* It is by this coagulation also that we perceive whether the blood is cupped or not, that is, whether the coagulum draws

cause of this harmony is in the solids themselves, either directly by an impression communicated to the blood by the vessels, or indirectly from some defect in the processes of nutrition and sanguification; some retention or vitiation of the secretions; some introduction of deleterious matter, or some fault in some one or mote of the vital actions. According to Mr. Hunter's" own definition (p. 28), action requires organization, and yet the great difficulty which he is even now combating is, how the blood, an unorganized fluid, should possess life. In short, there is the strictest kind of reciprocity between the solids and fluids; not, however, arising as parallel effects, but as cause and effect; the solids, heing altered, necessarily modify the blood, and the blood, being-modified, as certainly reacts upon the solids. In this point of view, to employ the words of Andral, " On ne trouve plus de sens aux disputes des solidists et des humoristes ; l'economie ne parait plus qu'um grand tout, indivisible, dans l'etat de santc oomme dans l'etat de maladie."] * [The buffy coat is undoubtedly mainly due to the cause which Mr. Hunter has assigned. Dr. Davy, however, has remarked, and I think the observation will be borne out by the experience of every one, that this phenomena is sometimes exhibited, even in a marked degree, although the coagulation shall have taken place more rapidly than usual; nay, a bluish and transparent lymph may often be observed to have separated from the other parts within thirty seconds after the blood is drawn, and consequently much sooner than under ordinary circumstances. There seems, therefore, reason for believing that the buffy coat is refernble in some measure to a greater relative d fference in the specific gravities of the coagulable lymph and red globules than natural, as well as to the slowness of the coagulation. Mr. Hunter partly also accounted for the appearance of buffy blood, by supposing that " the blood has an increased disposition to separate into Us component parts ;" a supposition which I eannot but think is borne out by many facts.] THE BLOOD. 31 together and its edges rise; and then we say that the blood is not only inflammatory, but highly so, showing great strength in the constitution : if, on the other hand, it lies flat in the cup, and makes an even uniform surface, we know it is rather loose in its texture (although it may be still buffy), which shows that the powers of the constitution are weak. The red globules abstracted, or the red blood abstracted from the other parts, need hardly be considered, as they hardly explain anything. The serum also explains but very little ; there may be more or less of it than common, but in itself it explains very little. The power of coagulating in the blood is greater when out of the circulation and exposed to common air, even more than when extravasated in some cavities of the body, the necessity or use of which is evident, for by this it becomes more effectual in stopping extravasation. A striking instance of this kind happened in the crural artery of a boar. I cut it through and allowed it to bleed ; but before the animal became weak, or at least had the appearance of weakness, the bleeding became less and less, till at last it stopped. On examining the artery, it was found to have a quantity of coagulated blood opposing and surrounding its cut end like a mop, through which the blood could not pass. This power of coagulation, especially when exposed, enables the blood to unite external wounds more readily, and of course preserves the living principle better, and keeps the internal parts from exposure in many wounds which otherwise would become external: by this means they are united by the first intention. In all inflammatory dispositions in the solids, whether universal or local, the blood has an increased disposition to separate into its component parts, the red globules become less uniformly diffused, and their attraction to one another becomes stronger, so that the blood when out of the vessels soon becomes cloudy or muddy, and dusky in its colour, and when spread over any surface it appears mottled, the red blood attracting itself and forming spots of red. This is so evident in many cases that it is hardly necessary to wait till the whole coagulates to form a judgment of it. I think I can say when the blood is coming from the vessel, by its appearance in the stream, whether it will be sizy or not. When the blood has not an inflammatory disposition, the stream has a degree of uniformity and transparency in its appearance ; but it is only an eye accustomed to it that can make this distinction. If the inflammatory-disposition of the solids arises from fever, this disposition in the blood is universal. If there is universal inflammatory disposition, from some local irritation, the blood is still universally affected. But if the inflammation is local, and the constitution is not affected, the disposition in the blood is not universal: how far there is local inflammatory disposition of the blood I do not know, but there is reason, however, to suspect 32 HUNTER'S PRINCIPLES OF SURGERY. it, from the ready union of parts under inflammation. If the blood does become inflamed in passing through an inflamed part, we must suppose that it immediately loses that disposition when it meets with parts in perfect health.* These properties, namely, increase disposition to separate, and a disposition to become a firmer solid, always show increased disposition for action in the living principle, and also, most probably, increased power. It is one of the signs of strength of the living powers although the materials for action are weak. The use of this change in the blood is evident, since it is made fitter for uniting parts by this means ; and it is from this disposition that the blood retains its living principle sufficiently long till union takes place. Unless the stimulus of necessity for coagulation is given by the solids, the extravasated blood will not coagulate, it will only act as an extraneous body, which often happens where union is unnecessary, improper, or hurtful, as in cases of contusion where the blood remains fluid in the cellular membrane. This disposition to coagulate when out of the vessels, or when retained in them without motion till the consciousness of the use of motion, and of course of fluidity, is lost, in one of the effects of the life of the blood. I have used the word consciousness because we have no language existing answerable to all my views of the animal economy, and to coin words would not answer the purpose, because then I must have a dictionary of my own. I have not a word for expressing the cause of those actions which take place in the body, as if it was conscious that such and such things were going to take place. There are actions in the body which come the nearest to consciousness of the mind of anything that I can conceive, and therefore I make use of this word; but it is commonly applied by philosophers only to the mind. Coagulation is a species of attraction arising out of this irritation.t It may be considered as a species of generation, for it is

* [That the blood undergoes peculiar changes, losing its globular character, its transparency, and the vividness of its colour, as well as its motion, in the vessels of inflamed parts, it is evident from the observations of Levret, Kaltenbrunner, Dollinger, and others, who have microscopically investigated this subject. These changes are most likely due to the influence of the vessels upon their contents; but to suppose that the blood itself can be the subject of inflammation, is to suppose it endowed not only with life and organization, but with life and organization of a high degree, for from the best observations which have been made it does not seem probable that those animals which are lowest in the zoological scale are capable of inflammatory action. Certainly we can form no definite idea of inflammation, except as connected with vascular and organised parts, although, from what i3 said further on, Hunter did not carry his Ideas of the blood to that extent.] f [Hunter uses the term irritation in place of the exciting cause. His meaning, therefore, seems to be that the consciousness of necessity is the exciting cause of coagulation, or that coagulation arises from the irritation of this consciousness. This is an instance of false logic, or of reasoning from final causes which he THE BLOOD. 33 the first action or establishment of a power of action within itself, so as to form itself into muscular fibres, the only powers in an animal; these, again, with other parts, form organs to act on the materials from which they arose, for their own support. I will relate a case in proof of most of the arguments which I have employed respecting the life of the blood. It is one of many. A man came to St. George's Hospital who had a hydrocele, for which he was tapped with a lancet. The water was clear serum: when this was evacuated, the testicle to the feel was found to be larger than natural. About a month after, the tunica vaginalis became as full as before ; the radical cure was now determined on, the tunica vaginalis was slit up its whole length, and the fluid, which was now bloody, was evacuated. The testicle, on being exposed, was found larger than natural, and was extracted. On the body of the testicle, and nearly in the direction of its long axis, and opposite to the orifice in the sac made by the lancet when the water was first evacuated, lay a coagulum of blood, dark in colour, almost like a leech when that animal is shortened, about two inches long, and of the thickness of a common sized little finger. In the angles between the epididymis and body of the testicle lay another coagulum, adhering in some places to the epididymis, in other parts loose to the body: it was attached only at one end. The adhesions of the large coagulum to the body of the testicle were firm, although it would admit of separation. This was made at one end, when fibres were plainly seen running from the testicle to the coagulum. The adhesion of the small coagulum was in many parts still firmer. All over the tunica vaginalis there were a great many vessels full of blood, and in many parts coagula of blood-like extravasation. In this state I had a drawing made of it, and a small part magnified, to show the vessels and the dots of extravasation as they then appeared. By being put into water all these vessels and dots disappeared, and the parts became white. I then injected the testicle by the spermatic artery, which succeeded extremely well. On examining the part I observed the following appearances. The surface of the testicle and tunica vaginalis had resumed the former appearance, only with this difference, that the injection was of a lighter red than the blood to the naked eye, and much more so to a small magnifier. The vessels on the surface were very distinct, and the dots, where the extravasation of injection was as if there had been extravasation of blood. The coagulum on the tunica vaginalis now appeared vascular; the surface of the adhesion, for about one twentieth of an inch, was injected and extremely full of distinct vessels. The smaller coagulum was injected

not unfrequently displayed: he has described the objects to be attained by coagulation, and he here states that the necessity of affecting these objects is the cause of the coagulation, which is much the same as to say it is so, because it is so. It is evidf nt that this does not in the least help us to discover the proximate causes of ooagulation.] 34 HUNTER'S PRINCIPLES OF SURGERY. in many places through and through its whole substance, in the other only for a little way. If it should be asked, How came those coagula there 1 The answer is the blood from the wound made by the lancet in the tunica vaginalis passed into the cavity, and then coagulated on the testicle directly opposite to the wound, and a small quantity of the blood which got down to the chink between the testis and epididymis coagulated there also. That this is the most probable way of accounting for it is, I think, strengthened by another case, where the tunica vaginalis was found adhering to the testicle, when performing the radical cure, at the very part where he had before been tapped. In half a year probably this coagulum would have become wholly vascular, and probably in a little longer time the whole would have been taken away; because, being vascular, it would have had absorbents, which would have taken it all, as a useless part, into the constitution. The tunica vaginalis filling again so rapidly in this case was perhaps the reason why it did not adhere to the coagulum on the other side, so as to produce a union between the two parts. Quaere, For what purpose did this coagulum become vascular 1* for no visible purpose could be answered by it, as absorption, we may suppose, might have taken place as easily in a coagulum as in the cellular membrane. But perhaps absorption not going on here was the cause of the collection of water; and adhesive inflammation evidently took place here that it might be able to absorb itself. Thus, then, the materials of which the blood is composed are joined with the living principle: in consequence of which the blood, if properly disposed, is capable, when extravasated, of forming itself spontaneously into parts fit for motion, and for performing all the offices of any part of the living whole, successively receiving the stimulus of nature from the surrounding parts to form itself into a similar part, as bone, cartilage, &c. In many diseases not inflammatory, namely, those called putrid, where the solids have a tendency to fall into those changes natural to animal matter deprived of its preserving principle, the blood has no disposition to coagulate, nor the solids any power of raising

* [The opinion that coagulated blood can become vascular, and so afford the common basis of union by the first intention, was firmly entertained by Mr. Hunter; but the proofs which are here adduced in favour of such an opinion are by no means so conclusive as they should be to establish so important a doctrine. For, not to mention the length of time which elapsed, in the present cases, between the injuries received and the appearances observed, the situation and definite form of the coagula would rather favour the idea that they proceeded from effused lymph, which became more or le3S intermixed with effused blood. Such an intermixture is generally observed in cases of wounds and operations, but I am not aware of any unequivocal example of pure coagula which have been observed to become vascular, although it is scarcely possible that this should have escaped observation if it were at all frequent. See Plates I. and II. for the appearance alluded to in the text.] THE BLOOD. 35 inflammation, both having taken on the same disposition. In such a disease both the principle and power are diminished, so that life is hardly able to preserve the matter from falling into its natural changes, though it has still a disposition to keep the vital parts or body moving. Many kinds of death as well as putrid diseases produce this effect on the blood: an instance of which was met with in a gentleman, who being in perfect health, died instantaneously from passion, this having been so violent as to produce death in every part at once, and his blood did not coagulate. A healthy woman was taken in labour of her fourth child. As the child was coming into the world the woman died almost instantly. On opening the body next day, there appeared no cause for death whatever, every part being natural and sound ; but the blood was in a fluid state, nor did it coagulate on being exposed. A soldier, a healthy young man, confined for desertion, received a blow on the pit of his stomach from one of his comrades, from which he dropped down, and died almost instantly. On opening the body, no preternatural appearance was observed, but the blood was in a perfectly fluid state, and did not coagulate when taken out of the vessels and exposed a considerable time. In animals struck dead by lightning the blood does not coagulate nor the muscles contract, both being killed at once. There are other instances. Two deer were hunted to death, in which case they acted until the very power of action ceased, and of course death ensued. On opening them the blood was fluid, only a little thickened, and the muscles were not rigid, as we find them, where they are capable of acting, from the stimulus of death. In both cases the life of the solids and of the blood was destroyed at the same time and at once.* The observation that animals hunted to death are tenderer than those killed by other means, is not uncommon. There is a natural action of the living body which destroys the life of the blood in the act of extravasation; this is the discharge of the menses in women. If that discharge is natural and healthy, the blood does not coagulate; but, on the other hand, if the extravasation is not a healthy one, the blood coagulates as it is extravasated, and comes away in clots. This perhaps is best demonstrated in cases where the hymen is unperforated and the menses are accumulated. This observation leads us to understand

* [The diversity of circumstances under which the blood remains fluid after death at present renders any generalization upon the subject impossible. This is so much the case that many able physiologists of the present day are disposed to ascribe the incoagulability of the blood to a cause the very reverse of that assigned by Hunter, viz. to a greater residual vitality in the blood and vessels than in ordinary death, by virtue of which the fluidity of the blood is preserved until the disposition to coagulation is lost. But this explanation, like the former, explains only half of the cases. See Notes to the Treatise on the Blood and Inflammation.] 36 HUNTER'S PRINCIPLES OF SURGERY. something of the nature of the menses; for, depend on it, where a woman has her menses come away in clots, it is not a natural but a diseased discharge. To prove that the blood and the solids correspond very much in s their actions of death, we shall only generally observe, that when an animal dies in the common way, it is by the vital actions being first destroyed; but life still exists, for the muscles contract and the blood coagulates. But if we destroy life instantaneously, or along with the vital actions, then the muscles will not act, and the blood will remain fluid.* These changes in the blood, which appear spontaneous, are not really so ; they arise from irritation in the blood itself as much as any actions in the solids. This irritation excites the natural action of the blood, which produces these effects and all the properties we see the blood possesses in either a healthy or diseased state. We cannot suppose the blood has a power of communicating sensations, as it cannot have nerves; its living powers are therefore those of simple life, and it is similar in that respect to the solids of many animals. As sensation is a principle superadded, and intended to convey fixed intelligence, it is necessary for a moving part to have it; but when it becomes a fixed and solid part it opens a communication with the mind. Thus far I have endeavored to show that the blood is as much endued with life as the solids are ; and the only difference between the two is that the solids have construction, called organization, producing considerable visible effects, while the blood, not having this construction, does not produce these visible effects. The truth of this theory will appear more evident in treating of the diseases of the animal body.t

* [In Bichat's language, the animal life dies first, and after that the organic life. The muscles stiffen by organic contractility.] f [The reader will form a better idea of the greater copiousness of the present copy of Lectures as compared with Mr. Parkinson's " Reminiscences," when he is informed that the whole of the preceding pages are comprised in less than seven pages of the latter. The consideration of the blood is less fully entered into here than in the Treatise on the Blood and Inflammation; but the reader will not fail to observe that Mr. Hunter often speaks with less reserve on many points in the former than in the latter; although in judging of his opinions, those contained in the Treatise on the Blood should undoubtedly be preferred, as being the result of his last and most deliberative judgment.] ORGANIZATION AND ACTION. 37 CHAPTER IV.

ORGANIZATION AND ACTION.

General views of organization and action—Arrangement of matter into certain forms to answer the end required ;—these structures combine to form organs ; __organs arranged according to certain laws constitute animals.—Organization and life distinct from each other.—Action exists in every part of an animal;— depends on contractility.—Of two kinds ;—common—and peculiar.—These are mutually dependant;—of the first kind, all involuntary ;—of the second, nearly all so;—cessation of the latter in disease;—Mr. Hunter's own case.— Of the second, digestion, circulation, and respiration are most closely connected with the first;—others, as motion of the limbs, more distantly.—Motion may be caused by elastic forces reacting, as in ligaments.—Conclusion.

From what I have said above, it must appear that original or common matter has been first so decomposed, and then again so combined, as to become animal matter. This animal matter next became so arranged as to become alive. Now I shall observe that these combinations and arrangements are differently modified, so as to produce the various kinds of animal substances; some of which have their parts so disposed as to have motion among themselves, as muscles; others to have sensation, as brain and nerves ; and in others the living parts are so disposed as to acquire other properties, as elasticity, rigidity, &c. Solidity, in a certain degree, is necessary for self-motion; for parts cannot produce motion in one another without some resistance or fixed point of motion. We therefore find the acting parts of an animal composed of solids, or the parts which compose them could not coalesce together by the attraction of cohesion ; and it is necessary that it should be so, as without this no determined action could be produced. Now we have gone so far with the materials of an animal, let us next examine how these materials are disposed so as to form an animal. These materials may now be considered in a mechanical point of view, like the component parts of a machine, each of which has its destined use and own peculiarity of form. These are united with each other to form parts, the whole forming organs of various kinds to produce the mechanical effects required. These organs, again, united according to certain established rules, form animals. This compounding of animal matter is what should be understood by organization. Now if this idea of organization is just, organization and life are two different things; for, according to this definition, a dead body is as much organized as a living one, for in the dead body the same mechanism exists as in the living one. Organization, then, comes nearest our ideas of the mechanical 4 38 HUNTER'S PRINCIPLES OF SURGERY. formation of parts, and the ultimate effect must be mechanical; for it is impossible to produce motion in matter without having a mechanical effect. Having considered simple life, and the general idea of what is called organization, we shall next consider the Actions of an Animal. We have said that animal matter is so constructed as to be endued with a power of self-motion, as in a muscle; and as we can hardly conceive any part of an animal entirely passive or free from motion, since all parts grow and are nourished", we must suppose this muscular structure very universal in an animal body, though this power has been considered principally in regard to muscles, properly so called, whose actions are plainly visible to the eye.* The different necessary circumstances attending the composition of a muscular fibre, with the mode of action of a muscle, we shall not touch upon, the field being too large for my present purpose. I shall only observe that they are the animal powers by the immediate actions of which every, the smallest, part of an animal is moved.f Every machine has its power; a clock has either a spring or weight, and so on. In mechanics the parts are dependant on one another, so that some one power is necessary to put the whole in motion; in mechanics too there is commonly but one ultimate effect produced, whereas in an animal body there are a thousand. The powers therefore of an animal body are differently placed and circumstanced from what they are in an inanimate machine : it is not one power that is setting the whole to work, because if that were the case an animal's actions would always be the same, but he is at rest in one part, moving in another, and so on; and as this is the case, he must have power in every part, so that his powers are diffused through the whole animal, which is almost composed of powers. The actions of an animal, considered as a whole, should be divided into two kinds. 1st, Those actions common to every part alike, such as those which are employed in the internal operations of the machine, as growth, alteration, building up, taking down, &c, every individual part (the smallest conceivable J) acting for

* [The author has elsewhere (see Introd. to Inflam.) defined life to be that power which renders the body " susceptible of impressions which excite action;" a definition which, however brief, exhibits in miniature the leadiug features of Bichat's celebrated hypothesis, according to which all the actions and phenomena of life are ultimately referred to two primary principles—namely, sensibility and contractility.] t [The reader is referred to Mr. Hunter's Croonian Lectures on Muscular Motion, in the fourth volume, where will be found a more full account of this subject.] X [It seems now to be generally admitted by microscopical observers that even the globules of the blood possess an inherent power of motion, in their quality of organized parts. Wolff, Dollinger, Treviranus, Kaltenbrunner, &c. have noticed a variety of movements of this kind, which are principally of a rotary or volvular kind. See Revue Med. vol. ix. 1828, and Journ. des Prog. des Sciences Med. vol. viii. 1828, and also the Treatise on the Blood and Inflam- ORGANIZATION AND ACTION. 39 itself only, which actions may be called immediate. These are probably performed by the ends of vessels, whether the terminations of arteries or the beginning of absorbents ; likewise the actions of the brain are of this kind. 2d, Those actions which are of whole parts, and which vary according to their composition or construction, being employed chiefly respecting other matter, not for the immediate use of themselves, as in those above mentioned, but still absolutely necessary for the first. These actions are of whole parts, as the stomach, heart, organs of respiration, organs of sensation, mind and will. That these actions differ from the first is evident, because the organs in which they are found have also the first, and are indebted to the first for their existence, in the same way that the first are indebted to the second for their continuance : the stomach, lungs, heart, and other organs of life, may be said to be continually supplying materials with which the first are employed in building and repairing the system. The second kind may be called labourers, being subservient to the first, which, as being engaged in laying down and taking up parts, may be called the bricklayers. It is the first which compose the movements of the true animal, being those which are immediately employed about itself. It is the operations of these which properly constitute the animal economy respecting itself, and it will be principally these which I shall consider. The whole of the first kind of actions are involuntary, the will having no power over them, the mind being not even conscious of them, although it has involuntarily considerable influence over them under circumstances of diseased and irregular action. Most of the actions of the second kind are subservient to the first, and are absolutely necessary to the continuation of their existence. These have therefore a certain degree of regularity, and according to the relationship or immediate necessity of the second to the first are these second permanent and constant: indeed we seldom find in them any intermission, perhaps never in health; however, in disease they are sometimes stopped. There have been instances where the motion of the heart has ceased, and also the involuntary action of breathing :—this once happened to myself. I had the gout in my feet three springs successively, and missed it the fourth. In the fifth spring, one day at ten o'clock in the forenoon, I was attacked suddenly with a pain nearly about the pylorus: it was a pain peculiar to those parts, and became so violent that I tried every position to relieve myself, but could get no ease. I then took a tea-spoonful of tincture of rhubarb, with thirty drops of laudanum, but still found no relief. As I was walking about the room, I cast my eyes on a looking-glass, and

mation, where this subject is further considered. Tiedemann calls the bloodglobules "the elementary organic forms;" and several of the French physiologists have thought that they might not improperly be classed with the infusorial animalculae.] 40 HUNTER'S PRINCIPLES OF SURGERY.

observed my countenance pale, my lips white, and I had the appearance of a dead man looking at himself. This alarmed me. I could feel no pulse in either arm. The pain still continuing, I began to think it very serious. I found myself at times not breathing ; and being afraid of death soon taking place if I did not breathe, I produced a voluntary action of breathing, working my lungs by the power of my will. I continued in this state three quarters of an hour, when the pain lessened, the pulse was felt, and involuntary breathing began to take place. During this state I took madeira, brandy, ginger, and other warm things ; but I believe nothing did any good, as the return of health was very gradual. About two o'clock I was able to go about my business. Here, then, was a suspension of the most material involuntary actions, so much so that the involuntary action of breathing stopped, while sensation and all the voluntary actions were as strong as before. Quere, What would have been the consequence if I had not breathed 1 At the time, it struck me that I should have died ; but that most probably would not have been the consequence, because, most probably, breathing is only necessary for the blood when it is circulating ; but as there was no circulation going on, so no good could have arisen from breathing.* The stomach appears to have been the seat of this affection. Affections of the stomach appear to have more influence on every part of the body than any other one part has on another; and this sympathy is reciprocal, for every part has a power of affecting the stomach, which shall be more fully treated of hereafter. Of the second kind of actions, those which may be considered as having the nearest relationship to the first, are digestion, circulation, and respiration; these are all secondary actions of the machine. Those which are not so closely connected with the first, but respect more the actions of other parts of the same body, or what may be called remote parts of the animal economy, are the actions of muscles in moving the limbs, sensations, and voluntary actions employed on external objects, as progressive motion, modes of catching food, &c. We may just observe, that in a muscle itself which has the power of moving other parts, we find the two kinds of actions; first, growth and support as in every other part: and secondly, the action peculiar to the muscle itself. The first kind of actions'arise immediately from the living principal, and have

* [It is probable that the circulation, although enfeebled, still continued to be carried on in this case as in Lipothymia, occurring from severe and sudden injuries to vital parts. It would be contrary to every fact with which we are acquainted to suppose that the animal and organic functions could be executed or maintained in an active state without a due supply of fresh blood. The respiration is almost if not altogether suspended during the state of hybernation; but then the animal functions, and as far as we know the organic functions also, are suspended. The same thing likewise occurs in those states which have been denominated trances and in cases of Asphyxia.] ORGANIZATION AND ACTION. 41 always been ranked as involuntary actions; the second are either involuntary, as the actions of whole organs,—the stomach, the heart, &c,—or are voluntary and dependent on the will, as common muscles, &c.: but these last I shall leave till I have spoken of the brain and nerves. Besides this action in parts, which I have said is confined to muscles, there is another mode of action introduced, that of parts having the living principle which yet have not a power of selfaction like muscles; these are the elastic ligaments. The elasticity of these parts does not depend on life, for it exists equally in dead as in live parts. Ligaments are employed to assist muscles in keeping certain parts in their places, the position of which is long continued. They may be considered as producing a secondary action in the machine. These are more common in some parts in some animals than in others; such as the neck of quadrupeds, especially those with long necks, as the camel; and on the abdomen of some animals, as the elephant: this power is also introduced in the vascular system. There are other parts' introduced into the machine which possess no action that can affect any other part, but have a land of passive use in the machine. These vary in their consistence according to the uses made of them, some being extremely firm, as bones, tendons, &c, which sustain the actions of different parts of the animal, and without which it could not subsist; others are less firm, and are employed in uniting the various parts as cellular membrane. From all that has been advanced, we see that by the juxtaposition or union of living parts organs are formed, which gives us the first mode of action, and the form of bodies gives the secondary mode. By the union of these various parts compound motion is produced. In this manner the whole of the most complicated animal machine is produced. The power of self-action which animal and vegetable matter possesses, distinguishes it from matter endued with any other properties than life, and also distinguishes living from dead matter.*

* [Muscular contractility, which bears not the slightest analogy to any other power of matter, was yet frequently confounded at the time of Hunter with the principle of elasticity. Hunter was the first to show that this was never the source of actual power, like muscles, but depended on a reaction in bodies in a contrary direction to the original impressing force, and always in proportion to it. It is still, however, very difficult to refer to their true causes many of the phenomena presented by skin, membranes, fibrous coats, &c. which obviously contract and relax in various degrees under different conditions of the system. Most frequently these phenomena are to be accounted for on the principle of tonicity, a power analogous to muscular contraction. Some, however, have been disposed to assign elasticity as the sole cause. (See Bostock's Phy., Vol. I. ch. iii. and Majendie's Lect. 8—10, apud Lancet, Vol. I. 1834—5.)] 4* 42 HUNTER'S PRINCIPLES OF SURGERY. CHAPTER V.

FUNCTIONS Or NUTRITION AND ABSORPTION.

The Stomach ;—peculiar and essential to animals;—intimately connected with other vital organs;—less with parts not vital;—sympathy with internal parts greater;—compared with the sympathy of the brain with external parts;-— greater with ligaments and tendons than with muscles.—Sympathy of the stomach with the mind. Vascular System;—its actions necessary to be understood.—Arteries:—secretion.—Veins;—formerly supposed absorbents.—Absorbents.—Relative offices of the three systems of vessels.—Various kinds of absorption;—modelling absorption, as during the growth of bones;—absorption of entire parts.— Supposed solvent.—Mouths of absorbents.—Alterations of matter absorbed.— Table of absorption.

Of the Stomach.—Every animal body, however compounded, must have the means of support, especially as it is by gradual increase to complete its own magnitude. To this end the living parts fitted for preparing nourishment are thrown into the form of a bag, which is adapted for retaining the food; and this bag is endued with the power of secreting a matter which has the property of converting many vegetable, and all animal, substances into a substance of one kind. This part is called the stomach, and in the less perfect animals it not only makes a considerable part of the whole animal in respect to size, but also in respect to its use in the machine, being the most considerable part of the whole. It may be considered as the first part of an animal, ever becoming more and more simple as the animal becomes more simple ; and also as the animal becomes more simple, becoming proportionately the larger part of the animal. The stomach is the distinguishing part between an animal and a vegetable; for we do not know any vegetable that has a stomach nor any animal without one. It is the converter of the food by hidden powers into part of ourselves, and is what may be called the true animal, no animal being without it; and in many, perhaps in most, it is what constitutes the principal part of an animal. A polypus is little more than stomach. An animal can exist without any senses, brain, or nervous system, without limbs, heart, or circulation, in s'hort, without anything but a stomach. But for the continuance of the species you must have parts of generation; and a polypus is a stomach and parts of generation in one ;* and the complicating an animal is no more than adding other parts for

* [" Nothing more is necessary to complete an animal than the power of continuing the species, which power is superadded to this bag in many."__ Hunterian (MS.) Cat. Phys. Series, vol. i. p. 113.] FUNCTIONS OF NUTRITION AND ABSORPTION. 43 various purposes.* To one^animal which has a brain and nervous system, you have ten thousand without them. The power and operation of digestion is perhaps as curious a part of the animal economy as any whatever; at present, however, it is not for me to explain these operations, but it is necessary for me to take some notice of the connexion between this viscus and the animal economy in general; in doing which we shall find it to be as much the seat of universal stimulus and irritability as the brain is of sensibility. This connexion, as in the case of sensibility, is much greater in some parts than in others; the connexion that all the vital parts have with the stomach is much greater than between the others, which may be called voluntary, which is only sayino- in other words that the connexions among the vital parts is more immediate than between the vital parts and those which are

1 In diseases the brain seems to be intimately connected with the stomach, and vice versa. It was as necessary for the stomach to be connected with the whole body as for the brain, although not in so marked a manner; but that it is as immediately connected -with the body as the brain we may certainly say. The affections of the stomach with the body are not so strong as those ot the brain, the mind being made sensible of the least injury done to a part, while the stomach is not at all affected under many partial injuries of the body. The stomach is more affected from the internal economy of the animal than from external influence, which is the reverse of the brain ; for external influence in general can only be local, and local injury does not affect the stomach unless it be previously disturbed, or unless the injury is in certain parts, as the brain, the testes, and many of the vital organs, which, as I observed, have a more intimate connexion with the stomach. The strongest natural affections of the stomach, as respects the body, are those connected with nutrition. These are of the greatest consequence in the machine, and may be said to be of two kinds, namely, want, and the contrary. Want has often been known to produce madness: the contrary may be divided into two kinds,— repletion, and the want of health rendering nourishment unnecessary ; and under such circumstances of the machine it is refused to be taken in. Perhaps repletion may be only a negative affection of the stomach with the body; the other is a positive one, and is often

* r/Nothing can be more simple than the apparatus for digestion in the lowest animals; but in the higher animals "the parts preparatory and subservient to digestion become more complicated, and indeed so much so, that there "hardly any system in an animal more complicated in itself; and when we consider the varieties of these complications which take place in the various animals, they appear to be almost without end. " The parts subservient to digestion in the complicated animals bear a gjeat relation to the other properties of the animal," so that " animals in general might be tolerably well classed by these organs."—Ibid.] 44 HUNTER'S PRINCIPLES OF SURGERY. carried so far as to produce a sensation in the stomach, namely, sickness. The stomach is affected by injuries in parts of the body which have no connexion with nutrition, and more especially with parts which have the least action in the machine. Although it may be difficult to understand why it should happen, yet we find that the stomach is more readily affected by injuries done to tendinous parts, and those which have little sensibility, than by injuries of muscular parts, especially of muscles under the control of the will. This is very remarkable in strains of tendons and ligaments. The stomach is no less connected with the brain in the internal operations of that vise us concerning external objects or mental operations than in cases of real injury done to that part. A man cannot hear a horrible story or behold distressing circumstances but he will often experience sickness, vomiting, or purging, especially the latter. The Vascular System.—In many animals, especially the more perfect, the nourishment, or whatever is taken into the system, is taken up and carried from the stomach to the heart, and from thence is thrown out to all parts of the system, through tubes; and from the system it is again returned to the heart by other tubes or vessels. It is absolutely necessary for the surgeon to have a tolerably clear idea of the operations of these vessels. The teaching of the structure and offices of these different vessels more properly belongs to the anatomist than to the surgeon; but as there is one use of the absorbent vessels not generally known, and which is of great importance in many local diseases, and has also an immediate connexion with the original formation of the body, it will be necessary that I should explain this: at present, however, I shall do so but slightly, and .trace the action more at large in speaking of local diseases. For the better understanding the whole action of the absorbents, it will not be improper to give a short sketch of the vascular system. An animal body has in general been considered under the idea of an hydraulic machine, because it appears to be almost wholly composed of tubes in which fluids move. I shall not at present enter into all the different opinions concerning the uses of these tubes, especially of that system called arteries; how they are variously affected, and how they produce their various actions, according to the different stimuli either of health or disease; but shall only give some general ideas of the most important uses of the three different sets of vessels, namely, arteries, veins, and absorbents. Arteries.—These carry the blood from the general reservoir, the heart, to all the different parts; the veins bring it back again. The arteries constantly dispose of a part of the fluid which they contain in the different operations of the body, according to the different functions of the parts: adding to the whole where growth is necessary; making up losses where the whole is either improper or destroyed; and throwing out of the direct line of motion parts FUNCTIONS OF NUTRITION AND ABSORPTION. 45 of that fluid, which, according to the different affections and actions of these arteries, become considerably altered in the process : this is Prilled secretion* Juices so secreted are intended for various purposes in the machine: some for stimulants, as the bile ; some for mechanical purposes, as the tears, synovia, saliva, &c.; some for a store of nourishment, as the fat, &c.; while others are thrown out of the body as useless, because they have already performed all their purposes, as tHp urine o£C« Veins.—The other set of vessels, the veins, are considered as less active, being principally employed in bringing back the red part of the blood, after it has lost its most salutary parts, or done those offices, whatever they are, for which it was sent out. 1 his, of carrying back red blood, was not considered as the only office ot the veins; many of their beginnings was supposed to arise, not frornthe terminations of arteries, but from most if not all the surfaces of the body, internal and external; making so many inlets into the general system, and bringing matter into the common mass of fluid for the support of the whole, and also to bring back many of the parts secreted by the arteries from the blood for the different purposes ot the machine, such as synovia and lubricating fluids of all kinds; which fluids, having answered their different purposes, and having become unfit for every other use in the machine, were obliged to be brought back again into the circulation, to be thrown out of the circulation by the arteries. Absorbents.—Such were considered to be the uses of the veins before the discovery of the lacteals; but by the discovery of these they were deprived of part of their supposed offices, namely, that ot absorbing the chyle; still they were thought to absorb matter from the cavity of the intestines for the secretion of bile. The other part of the absorbent system, called the lymphatics, though long known, was not in the least suspected of performing the operation of absorption, but was still supposed to be the terminations of the extreme ends of the arteries, not large enough to carry red blood but only serum or lymph, though from their similarity to the lacteals, which were known to be absorbents, it became at last evident to common sense that they must absorb. Before this idea was started, the general opinion of the vascular system ran thus. The arteries were supposed to carry blood for nourishment, secretion, &c. throughout the machine; the veins to return the red blood, as also to absorb from every surface of the body; the lymphatics to return the lymph or blood which came along the arteries; and the lacteals to absorb part of the chyle from the intestines. But some experiments which I made to ascertain whether the veins of the mesentery absorbed, proved that they had not the power of absorption.* I do not suppose the veins, even in an erection ot * [See the details of these experiments in Vol. IV.] 46 HUNTER'S PRINCIPLES OF SURGERY. the penis, to have the power of absorption; but I consider the corpora cavernosa as veins through which the blood is constantly flowing from the arteries, and that other veins carry off the blood from the corpora cavernosa; that in erection there is a spasm on the extremities of these veins, which prevents the blood from flowing into them, in consequence of which an accumulation and distension takes place, which causes an erection, and this ceases with the spasm on the veins. By tying the veins of a dog's penis, I found I could cause an erection at pleasure, while the arteries continued free.* Now, therefore, the offices of the three systems of vessels were as follow: The arteries remain as before ; the veinsreconvey the blood to the heart, for a continuance of the actions of the arteries as before, but have lost their supposed power of absorbing; the absorbents alone are employed to take up whatever is to be carried into the circulating system. Now let us consider what are the substances always allowed to be absorbed. 1st, Extraneous matter, in which is included nourishment. 2d, Secreted, superfluous, and extravasated matter, whether natural or diseased. 3d, The fat. 4th, That portion of parts which, being absorbed, causes the waste of parts, as muscles becoming smaller, bones lighter, &c. Although these two last effects were perhaps not expressly said to be carried on by absorption, either by the veins or the other system of vessels, yet we must suppose it was understood. So far the absorbents have been considered as an active part in the animal economy; but, from a further knowledge of these vessels, we shall find that they are of much more consequence in the body than has been imagined, and that they are often taking down what arteries had formerly built up, thus becoming modellers of the body; and that they are also removing many diseased parts, which were beyond the power of cure. As these vessels are productive of a vast variety of effects in the animal economy, which are very dissimilar in their intention and effects, they may be viewed in a variety of lights, and admit of a variety of divisions. We shall first consider them under two views. 1st, As absorbing matter which is not part of the machine. 2d, As absorbing the machine itself.

* [In 1830 Mr. Houston announced the discovery of a muscle in the human subject which arises from the ramus of the pubes, and, crossing the dorsum of the penis to unite with its fellow in the mesial line, effectually compresses the dorsal vein whenever this muscle is brought into action. (Dub. Hosp. Rep. Vol. v. p. 459.) A similar muscle, but more perfectly developed, was much earlier discovered by Cuvier in several of the mammalia, to which that eminent anatomist assigned the true use (Anat. Comp. Vol. v. p. 102); in addition to which we may mention that the tongue of the chameleon possesses a highly erectile tissue, and is provided with a similar pair of muscles adapted to fulfil the same object. Tiedemann, Cuvier, Moreschi, &c, have confirmed the accuracy of Hunter's opinion respecting the structure of these tissues, namely, that they consist of veins enlarged at their origins, and not of a system of cells as has generally been supposed.] FUNCTIONS OF NUTRITION AND ABSORPTION. 47 The first is a well known office of the absorbents, and is of two kinds : a, the absorption of exterior matter, in which may be ranked everything that is applied to the skin, as also the chyle; b, the absorption of interior matter, such as many of the secreted fluids, the fat, the earth of bones, &c. It may be necessary to observe that I do not consider the fat and earth of bones as part of the animal, as they have no action within themselves, and have not the principle of life.* These actions of absorption are principally employed with a view to the nourishment of the animal, as also to answer many other purposes, as in the absorption of foreign matter, which is extremely extensive and is very important; for besides its salutary effects, it is often the cause of a thousand diseases, especially from poisons ; all which is not to our present purpose. The second office of the absorbents which we are to consider, is that of removing parts of the body itself, which may be of two kinds. The first of these is where only a gradual wasting is produced, either of the whole machine, as in atrophy, or of a part, as in the muscles of a leg or arm, from an injury done to a nerve, tendinous part, or joint: this I call interstitial absorption, because it is the removing a part of the body out of that part which remains, leaving the part still a whole or complete part; a muscle, for instance, that is wasted remains still a perfect muscle. The second is where the absorbents are removing whole parts of the body, and this may be divided into natural and diseased. In the natural, these vessels are to be considered as the modellers of the original construction of the body; and if we were to consider them fully in this view, we should find that no alteration can take place in the original formation of many parts, either in natural growths or in parts arising from disease, without the absorbents being in action to take a considerable part in it. This kind of absorption I shall call modelling absorption. If I was to consider this function in these lights, it would lead me to a vast variety of facts, as extensive as those connected with any principle in the animal economy, for bones cannot be formed without it, nor probably many other parts. A part which was of use in one stage of life, and becomes entirely useless in another, is removed. This is evident in many animals; the thymus gland is removed, the ductus arteriosus and membrana pupillaris are removed. This process is perhaps more remarkable

* [In regard to the earth of bones, we may observe that its particles are arranged in a determinate and specific manner—constituting an organized body in the most extensive acceptation of that word as distinguished from inorganic matter generally, and from the amorphous ossific depositions which sometimes occur in membranes, muscles, glands, tumours, &c, in which no definite structure is observable. The peculiar stratification and fibrous texture of bone may easily be observed by calcination. This being the case, are we warranted in saying that the earth of bones, forming an organised part of the body, is not alive t] 48 HUNTER'S PRINCIPLES OF SURGERY. in the changes of insects than in any other animals. The changes in an insect are very curious. The insect is first a maggot or caterpillar, then goes into the chrysalis state, and comes out a butterfly. Whilst in the chrysalis state it is totally changed, the old parts are almost wholly taken up, and new parts formed ; and it is this modelling process that occasions these changes.* Bones do not grow by having new particles put into the interstices of previously formed parts, so as to remove these to a greater distance from each other, by which means they should grow larger,— as, for instance, if I put a sponge into water, the water getting into all the interstices makes it larger,—but they grow by the addition of new bone on the external surface.t I took a pig of a very large breed when young, bored two holes in the tibia, and put a shot into each, measuring on a card the distance of each from the other. I allowed this pig to grow up to its full size, then killed it and took out the bone, and I found the two holes at exactly the, same distance from one another as at first. Now if the bone had grown in all its parts these two shot would have been removed to a distance from each other proportionate to the growth of the bone. This fact is also ascertained by feeding animals on madder at different intervals, by which means we shall get strata of red and white bone. Since we know that bones do not grow by fresh matter being put into all parts, so as to push the old matter to a greater distance, but by new matter laid upon the external surface, let us see whether it is possible for bone to grow and retain its form without being taken down. Let figure 3, PI. III., represent the head of the thigh-bone of a foetus. Now if the increase was accomplished by superimposed layers, one over the other, as in figure 4, the head of the bone would necessarily become of an enormous size, and in time would come down so as to occupy the middle of the bone, while the cavity in the centre would not be enlarged. Absorption, therefore, must necessarily go on to keep the bone of its proper shape. Hence I call this the modelling process, for without this combined action of absorption and deposition the animal could not grow as it now does. The absorbents possess the power of removing complete parts of the body, in consequence of disease, an operation which is somewhat similar to the first of this division, or the modelling process,

* [It must be remembered, however, that in insects, where these changes, as Hunter observes, are the most striking, no proper absorbent vessels exist, and indeed the vascular system generally is very imperfect. The changes that take place in the insect transformation have been since ascertained to be rather a development of parts previously existing in a rudimentary state than a total change of parts. In the caterpillar are to be found the rudiments of the future butterfly.] t [See Vol. IV. for a paper detailing the whole of Mr. Hunter's experiments on this subject.] FUNCTIONS OF NUTRITION AND ABSORPTION. 49 but very different in the intention, and therefore in the ultimate effect. This process of removing whole parts in consequence of disease, in some cases produces effects unlike what it produces in others, one of which is a sore or ulcer; in other cases no sore or ulcer is produced, although the whole part is removed. The first I call ulcerative absorption ; but for the other I have not been able to find a term. This process of the removal of a whole solid part ot the body, or that power which the animal economy possesses of taking part of itself into the circulation by the absorbent vessels when necessary, is a fact that has not been in the least attended to, nor even been supposed possible ; and as I now mean to give a general idea of it, I may just be allowed once more to observe, that the oil or fat of the animal, and the earth of bones, have always been considered as subject to absorption, and some other parts of the body most liable to waste have been supposed to suffer by absorption ; but that any solid part should be totally absorbed is a new doctrine. This use of the absorbents I have been able to demonstrate. The first hint I received of it was in the waste of the sockets of the teeth, and also of the fangs of the shedding teeth, which was in the years 1754 and 1755 (see Treatise on the Teeth, first and second parts). This opinion was strengthened by what I observed in the process going on in the exfoliation of bones. It may be difficult to conceive how part of the body should remove itself, but it is just as difficult to conceive how the body can form itself. They are both equally facts. The knowledge of their mode of action would perhaps answer but little purpose. This, at least, I may assert, that when any solid part of the body undergoes diminution, brought on in consequence of disease, it is the absorbent system that has done it; they are the thieves. The remote cause of absorption of whole and living parts implies the existence of two conditions, the first of which is a consciousness, in the part to be absorbed, of the unfitness or impossibility of remaining under such circumstances, whatever they be, and therefore they become ready for removal, and submit to it with ease. The second is a consciousness of the absorbents of such a state of the parts. Both these concurring, they have nothing to do but to fall to the work.* Now the part that is to be absorbed is alive, it must feel its own inefficacy and admit of absorption. The vessels must have the stimulus of imperfection of this part, as if they were sensible that this part were unfit; therefore take it up. There must be a sensation in both parts.

* [The reader, I imagine, will scarcely refrain from smiling at the naivete with which our author here ascribes consciousness and intelligence to an animal body, to an extent little inferior to Boerhaave, Van Helmont, or even Stahl. It were devoutly to be wished that the body politic possessed a similar consciousness of what ought to be done, and an equal will and power to carry its resolutions into effect.] 5 50 HUNTER'S PRINCIPLES OF SURGERY. When the part to be absorbed is a dead part, as nourishment and extraneous matter of all kinds, then the whole disposition is in the absorbents.* This is the only mode in which this power is capable of producing such effects, and, like all other operations of the machine, arises from either stimulus or irritation, all the other modes of destruction being either mechanical or chemical.

[It is by the progressive absorption that matter, or pus, and extraneous bodies of all kinds are brought to the surface of the body. It is by this process that bone exfoliates and sloughs are separated. It is the absorbents which remove whole bones while the arteries are forming new ones. It is this operation that removes the alveolar processes when the teeth drop out of themselves, or are taken out by art; as also the fangs of the shedding teeth, which allow them to drop out; and it is by this means also that ulcers are formed. It becomes in many cases a substitute for mortification, in which cases it seems to depend upon a degree of strength and vigour superior to that where mortification happens; and in many cases it finishes what mortification had begun, by separating the dead part. From all this, we must see that the causes of the absorption of whole parts are many. Pressure appears to be one of the greatest causes of absorption, and it is commonly a cause of the progression. It produces its effects not in all cases in proportion to the pressure, but according to the pressure and other circumstances combined; for we find very different effects from the same quantity of pressure: thus, under one circumstance, pressure shall give sign3 of strength, and produce an increase, or thickening; but under another circumstance the same quantity of pressure shall produce waste, or an absorption of the parts. This difference in effect, from the same quantity of pressure, depends upon the pressure being from without or within, for the first effect of the irritation of pressure from without is the disposition to thicken, which I have asserted is rather an operation of strength; but if it exceeds the irritation of thickening, then the power appears to give way to it, and the absorption of the parts pressed gives way to it. Pressure produced by an extraneous body surrounded on all sides, such as pus in an abscess, acts equally on every side of the surrounding parts, and therefore, ever}' part being pressed alike, ought, from this cause singly considered, to produce absorption of those surrounding parts equally on all sides, supposing the parts themselves similar in structure, or, which is the same, equally susceptible of being absorbed : but we find that one side only of the surrounding living parts is susceptible of this irritation ; therefore one side only is absorbed, and this goes on in regular progression. The side of the cavity which is susceptible of this irritation is always that which is next to the external surface of the body ; therefore we have always extraneous substances of every kind determined to the skin, and to that side of the body on which the extraneous substance lies, or to which it is nearest, and that without having any effect upon, or producing ihe lea6t destruction of, any of the surrounding parts. From this cause we find abscesses whose seat is in or near the centre of a part readily determined to the surface or side in preference to another; and whenever the lead is once taken, absorption goes on there only. But as some parts of the body are more susceptible of" this irritation than others, we find that such parts are often absorbed, although they are not in the shortest road to the skin; and of such structure is the cellular * [It is difficult to conceive how the absorbents can act on detached solid Rubstances, incapable of solution, as bone for example ; yet portions of dead bone are often observed to be entirely absorbed in cases of necrosis; and in some experiments made by Mr. Thomas Blizard, in which disks of bone were bound on over ulcers; the surfaces of these disks were found to be eaten out,or destroyed, just as in common caries.] FUNCTIONS OF NUTRITION AND ABSORPTION. 51 membrane. We find exfoliations of bones, as well as all other extraneous bodies approaching the skin in like manner, and from the same cause. But the progressive absorption is always more or less attended with the interstitial, and assisted by it. The vessels in general would appear to have more powers of perfecting themselves when injured than any other part of the body, for their use is almost immediate and constant, and it is they which perform the operation of restoration on the other parts; therefore they themselves must first be perfect. They would seem to have more of the polypus in them than any other part of the body. This is perhaps more in the absorbents than in the arteries and veins, for we can conceive a part injured by accident, and, as it were, standing still for a little while; but we see ulceration going on very rapidly, which prove6 an immediate formation of vessels for absorption.*] The knowledge of the use of the absorbent vessels is of late date, and the knowledge of their different modes of action still later. Physiologists have endeavoured to account for their modes of action on the principle of capillary tubes at their beginning, and this is the most common notion, because it is a familiar one. But this is too confined an idea for an animal machine; nor can it account for for every kind of absorption. But as solids are often absorbed, as indurated tumours, coagulated blood, earth of bones, &c, they were driven to the necessity of supposing a solvent. This may or may not be so; it is one of those hypotheses that can neither be proved nor disproved, and must for ever rest as an opinion. My idea is, however, that nature leaves as little as possible to chance alone, and that the whole operation of absorption is performed by one action in the mouths of the absorbents. But even under the idea of capillary tubes, physiologists were obliged still to have recourse to the actions of these vessels, to carry on the matter absorbed; therefore they might as well have extended the action to the mouths of the vessels. As we know nothing of the mouths of these vessels, it is impossible we can form any opinion that can be relied on; but as they are capable of absorbing substances in a state of solidity and fluidity, it is reasonable to suppose that they have different modes of action; for although any construction of parts that is capable of absorbing a solid may also be such as is capable of absorbing a fluid, yet I can suppose a construction capable of absorbing a fluid that is not fitted for the absorption of a solid, though this is not likely. To see the possible correctness of this notion more forcibly, let us only recollect the variety in the mouths of different animals, and * The preceding paragraphs are transcribed from the Hunterian Catalogue (Phys. Series, vol. ii. p. 5), and are also partly repeated in the work on Inflammation. They are in Mr. Hunter's own words, and serve to complete this subject. A long and interestingf note is added to this part of the Catalogue by the author, asserting the claims of his brother, Dr. William Hunter, to the discovery of the lymphatics, in opposition to the pretensions of M. Noquez. The whole note is very characteristic, and affords an excellent specimen of critical and sound judgment, of a certain combativeness of disposition, and of that homely but vigorous mode of expression for which Hunter was distinguished. 52 HUNTER'S PRINCIPLES OF SURGERY. I will venture to say that the mouths of all the different animal have not a greater variety of substances to work upon than the absorbents have; and it may be observed, that with all the variety in the mouths of different animals, this variety is only for the purpose of adapting them to the forms of solids, which admit of great variety, every one being capable of absorbing fluids, which admit of no variety. I have often said, on this point, that if we could see the mouths of these vessels, we might perhaps class the modes of absorption as animals have been classed, by their teeth, &c. Matter taken into the constitution by the absorbents is capable of being altered in its nature from what it was out of the constitution. Although this may have been conjectured or imagined, it never has been absolutely known, and even now the only proof we have of it is the change produced in venereal matter. If the matter of chancre or gonorrhoea be absorbed, it produces disease ; this disease is not similar to the original; it is not pocky matter which is produced from the ulcers, but this matter has been changed from its original nature in the circulation; although the change was of such a kind as still to retain its power of stimulating and producing disease: but as it was changed, the disease produced was not similar to that from whence it came. That there is a change in venereal matter is very evident, for if venereal matter out of the constitution be applied to a living part, it always produces an effect according to the nature of the-part, which part may be one of two kinds, either, 1st, a secreting surface, producing then gonorrhoea; or, 2d, a non-secreting surface, producing then a chancre. That this process of altering substances in the constitution is not a universal principle and common effect of all kinds of matter which enter the circulation, is evident; for we do not as yet know, for certain, of any other matter being altered.

TABLE OF ABSORPTION. Absorption for ^ Extraneous matter to become useful, as chyle, fat, &c. nourishment. } lnterstitial absorption of parts of the body itself, as cellular ' ( membrane, muscles, &c. Absorption of fExtraneous, 'hat have been useful, as synovia and other useless in secretions, become useless. convenient ~< f Producing wasting of a part, as a leg, nr hurtful 1 an arm, &c.; or wasting of the whole parts Parts of the bodyJ bodv- L itself. } rAs modellers in | \ | the time of L. J growth. In consequence of Absorption of the weakness, as in whole parts. J th?, removal of calluses. From parts becoming wholly useless, as the alveoli. OF THE BRAIN AND NERVES. 53 O a) . a 2"S f C of a leg or an arm, &c.; or of the whole t . .-.- 1 C Partial wasting < body, as in atrophy. Interstitial \ * £ of a callus of a ^^ absorption. ^Totaj wasting Df calluses, alveoli, testicles, &c. As when pus or any extraneous body~\ is brought to the skin I Attended with sup- In the process of exfoliation of bones, > DUration Progressive absorption. in me process ui exiuuauuu ui uuuco, /■ r,uration In the process of sloughing, I ^ In the formation of ulcers, In the removal of the fangs of the teeth. Without suppuration. JMixed, As in the progress of pus, tumours, &c. to the skin. CHAPTER VI.

Passive and active states of the brain;—too much influence attributed to the brain in the bodily actions;—actions of the brain;—five modes of impression on the nerves, or senses. Voluntary action becoming involuntary, as in chorea.—Of sensation. Connexion of the actions of the brain and nerves with life.—Of sleep ;—its importance in the animal economy.

We have hitherto traced animal matter from its change from common matter to animal matter, the particles of which have possessed such an arrangement as to produce life ; still it has other modes of arrangement, out of which arise other modes of action, and which only take place in some animals. These are the brain and nerves, which produce sensation, out of which arises mind and reason; for without sensation the mind could not be formed, nor could we reason ; it being always about some object that the mind is affected, or that we reason. In sensation the brain is passive, only receiving the impression from the nerves, according to their actions, called so many sensations. In mind it is active. Mind arises from a peculiar quality in the sensation, being expressive of some quality in the body which is the object of sensation, and which gives an action to the brain answering to those qualities, as agreeable and disagreeable, with all their different species, as love, joy, hatred, anger, &c.; which actions of the brain, or states of the mind, become the causes of particular modes of action in the body affecting both involuntary and voluntary actions. The heart beats quick or slow according to those states; sickness may be produced; purging, contraction of the bladder shall take place ; the voluntary muscles hardly obeying the will, but performing involuntary actions, according to the state of the mind. Reason, by influencing the will, becomes the cause of the volun- 5* 54 HUNTER'S PRINCIPLES OF SURGERY. tary actions ; and by this connexion all these principles can affect one another. Now the brain appears to be capable of two modes of action, and out of these arises every property of the brain. We may call the actions of the brain, mind ; objects shall affect our senses so as to form a peculiar state of mind: this I call mental impression. Again, the mind can reason and exercise volition respecting objects. The former is involuntary, and belongs also to brutes ; the latter is voluntary. For instance, I am challenged to fight a duel, volition, and reason determine me to go to it; but when at the place, my joints tremble, my stomach turns sick : this is the effect of mental impression, or feelings of the mind. The two operations are very different; and in general the feelings of the mind, if strong, will prevent all reasoning. Much more has been given to the brain and nerves than they deserve.* They have been thought to be the cause of every property in an animal body; that independent of them the whole body was a dead machine, and that it was only put in action by them. But although their actions are absolutely necessary in the machine, they are not so universally so as has been imagined. They are not the cause of growth, nor do they even preserve a part from death, although the whole as a whole cannot live without them. The nerves have but one mode of action, namely, that of conveying impressions; but this in two different directions: one from

* [It may here be remarked, that the author, on the whole, lays less stress on the nervous system in his physiology than it probably deserves, at the same time that he gives disproportionate importance to the stomach. Modern experiments have shown that the functions of digestion, nutrition, secretion, circulation, respiration, &c. in the higher animals are intimately dependent on the integrity of the brain and nervous system ; and though in some of the lower animals no traces of this system are discoverable, yet may we safely infer, from the irritability which these animals manifest, that something corresponding to a nervous system actually exists, constituting the materia vitse diffusa of the author. Something analogous to this has been suspected in regard to the stomach itself, in certain species of zoophytes, in which either there are no visible stomachs, or else the parts which are generally considered as separate and independent animals are regarded by others as merely a multiplication of stomachs belonging to the same individual. Some experiments also have lately been performed in America which show that undressed animal food undergoes a species of imperfect digestion when inclosed in fresh wounds : from which it seems probable, that notwithstanding the centralization of the vital organs in the higher orders of animals, the separate parts still exhibit traces of those vital endowments which in the lowest order of animals are diffused through the whole body, very much in the same manner as in vegetables. The proper objects of comparison, however, in the present case, are the stomach with the great sympathetic nerve or nerves of the viscera rather than with the cerebral masses. The superaddition of the latter has reference principally to the organs of external relation, very few of which exist in zoophytes and the simpler forms <>f beings. Physiologically, it is as difficult to. conceive of sensibility and contractility without a nervous system, or something analogous to this system, as it is to conceive of nutrition without digestive and circulatory organs.] OF THE BRAIN AND NERVES. 55 their extremities in the body towards the brain, conveying impressions made on them to the brain, in order to excite actions suitable to these impressions; the other, from the brain to the extremities, conveying the mandates of the will, &c. That mode of action which is from the body towards the brain is of two kinds. One is the internal feel of the body, of perfection, imperfection, power, want, &c. The other is of those feelings of the body which are to call forth the powers of the will to perform what are called voluntary actions, for the subsistence of the body, or to effect the actions which it cannot perform. The actions of the brain towards the body are also of two kinds: one in consequence of the feelings or state of the mind at the time, whether the actions of fear, courage, anger, love, &c.; the other, in consequence of the command of the will, called voluntary actions. Those of the body to the brain are the first in order; for it is the receiving the impressions that gives rise to the others. Of the latter, the first are the feelings of the mind, and the second the will and its consequences, namely, voluntary actions, or all those actions, directed principally to external objects, for which muscles are provided. As the nerves are perfectly passive till impressed by external objects, no one could have any sensation except while an impression is made on some of the senses. Therefore a man should not feel that he exists but in thought; nor could he do that if he had never received impressions to think about, for thinking is no more than the memory of impressions put into order by the mind; nor should he have those actions which naturally arise from the brain till the brain makes the impression on the nerves. The impression is made on the body, but the sensation is in the brain, for the effect (of a person's feeling in a part to which a nerve is distributed) on cutting or otherwise injuring a nerve, proves that sensation is in the brain, and not in the body; for if it was in the body, the sensation would be referred to the part injured ; but sensation being in the brain, and brought from the brain by the action of the nerves, or sensation being formerly in the brain, the action of the nerves we find is referred to the beginnings of that action by the combinations of the other senses ; otherwise it would be only in possession of the sensation without any reference. The reference produces a feeling in the mind receiving sensation, by joining it with the seat of impression. There are five modes of impression of nerves, or perhaps rather five modes of construction of parts, which are adapted to so many kinds of impression. These are called the five senses; but there are a great many kinds of sensation conveyed to the brain or sensorium. The five senses are no more than parts constructed so as to be capable of receiving impressions, or so many properties of matter. Perliaps all are capable of receiving the impression of touch, or 56 HUNTER'S PRINCIPLES OF SURGERY. pressure, if it could be applied to all, so that every nerve may be said to feel.* But, besides pressure, there are other properties of matter. Many bodies have qualities besides being tangible ; some only when in solution making an impression on the tongue and causing taste; the same bodies when thrown into vapour give smell: air, besides being tangible, has a peculiar motion, arising from its repulsive quality, called vibration, which strikes the ear and produces hearing. There arises another property in another species of matter, called light, which we know less of than any other, which has a power of pervading some bodies, called transparent, and gives us the sensation of sight; and from peculiarity in the formation of those transparent parts light becomes more determined in its direction. The sensation of the glans penis, tickling, and itching would seem to belong to feeling. The first, however, is certainly a different mode of action of the nerve from common feeling, and both itching and tickling require a particular mode of impression to produce them. An animal can bear with ease a certain quantity of common sensation, which quantity being particularly applied will give pleasure ; but if common sensation be increased beyond certain bounds, it gives great pain ; so that pain is no more than an increased sensation, such as the sense of violence committed to a part.f All the five senses are subject to the same mode of sensation when applied in the same way, namely, by touch, and if the impression is too strong, give the sensation of pain. For instance, if the retina be hurt, it gives pain, but not light; if the ear be hurt, it gives pain, but not sound ; if the nose be hurt, it gives pain, but not smell.J But there are exceptions to the two first, for a blow on

* [It would seem that Mr. Hunter thought that all the nerves of the senses were capable of conveying the sensation of touch or pressure, in addition to the sensation which they are specially fitted to convey. This opinion is not warranted by more recent discoveries. An impression on the retina, of whatever kind, excites the sensation of light. Majendie found that on touching the retina with a couching-needle no pain was excited, but the sensation of light: a blow on the eye has the same effect. If pressure be made with the finger on the sclerotic, a dark spot will be seen immediately at the point of pressure, where the function of the nerve is probably impeded, with a hallo of light surrounding it. Of the auditory nerve we know little; and on the tongue and nose the gustatory and olfactory nerves are so intermixed with the fibres of the fifth or nerve of feeling, that it is not easy to distinguish between their actions in such an experiment; but galvanism, which excites a pricking sensation in the skin, causes a peculiar flavour when applied to the tongue; and the smell of the electric fluid is well known.] f [If this were the case, we should expect to find pain differing only in decree, but not in kind. Some structures, as bone, ligament, and the fibrous structures generally, exhibit no common sensation, although they are actually alive to pain under circumstances of injury and disease.] X [To each of these organs are distributed branches of the fifth nerve, or th» OF THE BRAIN AND NERVES. 57 the eye often produces light, and on the ear sound. And besides, those senses are subject to diseases, where the sensation often arises without impression from without. The common actions of the body, that commonly arise from the will, often become involuntary, as in palsies, St. Vitus's dance, &c.; but I suspect that these actions still arise from the brain or mind, though not the will, because they do not take place in sleep ; nor do we find the same diseases in any animal but the human. Our senses being such, have their peculiar degree of sensation and their peculiar mode of receiving impressions, and when this is carried to too great a length, they become extremely uneasy : but it is an uneasiness different from pain ; it is the peculiar sense carried beyond what the mind can bear. Sensation is in proportion to the impression made on a part, joined with the susceptibility with which the nerve is ready to act. But for distinct sensation two things are necessary, namely, time and space. It is necessary that the impression should be some time in performing, because an impression may be too quick to excite sensation, or quicker than any action in the nerves, such as a ball passing through a man's body without his feeling it; but he is capable of feeling it afterwards, which arises from an action of the injured part, not from the violence itself. Neither must the time be too long, for an impression or an injury may be so slow as not to affect the nerves at all, so as to throw them into any action. A person, for instance, shall become dropsical, and the belly shall fill with water so gradually as to give no pain from the stretching of the muscles, peritoneum, &c.: but if you were to attempt to stretch the belly of another person in a given time to such a degree, it would produce pain in proportion to the violence. The space must also be determined, for a given quantity of impression may be concentrated so as to be within bounds of sensation ; for it would appear that a single nerve or a very few nerves are not capable of conveying sensation, however affected; for instance, a given quantity of light may be concentrated into such a small point as not to be seen. Every sensation, every mode of sensation, and every sense appear to depend on the quantity of nerves acted upon, and in a given time; therefore we have a great quantity of nerves going to parts that are allotted for strong sensation, that no impression may be made without affecting a great many nerves at the same time. The uneasiness arising from too strong impressions we can easily assign a reason for, as it becomes a means of avoiding that violence; but itching and tickling appear not to be so very necessary: however they must be of a service in the animal economy. I can conceive itching becomes a cause of our keeping ourselves clean, free from vermin, &c, and becomes a substitute for pain: it nanerve of sensation; it is by means of these that common sensation is furnishpd to the organs of sense, and through them that lesions excite the feeling of pain. See the preceding note.] 58 HUNTER'S PRINCIPLES OF SURGERY. turally leads us to the cure, which gives pleasure ; and the performance of it is almost similar to the indulgence of our natural appetites. This principle of sensation is our director with respect to all other external actions, but has no absolute power over the internal economy of the machine. But this first principle we shall find can influence the others very materially, and thus a compound principle will be produced. The brain and nerves also give the body a consciousness of its own muscular powers. This is more remarkable in other animals than in man: thus, a horse will at once know what he can leap, and will leap no more, nor attempt it; and indeed a man can for the most part tell. A nobleman (the Duke of Queensbury) who had broken his tendo-Achillis was fearful of walking about his room; but I advised him to do it as well as he could, assuring him that his gastrocnemius muscle, knowing its own business better than its master, would refuse to act if he walked, and that the action would be performed by other muscles. This he found to be true. But in the night time, I told him, I could not be answerable for what his muscles would do, therefore I thought proper to put the leg into a fit posture and secure it by a bandage. As the brain and nerves are composed of animal matter, and as that animal matter has life, or the first principle of action, in common with all the other matter composing the whole body, there arises necessarily an intimate connexion between those principles, and, though totally different in their peculiar actions, yet they become blended with each other, so that one seldom acts perfectly unless the other is in perfect order, each of them calling on the other to do its part; and when both these principles are in vigour and in perfect harmony the whole machine is in health. Life is coeval with the existence of the animal or vegetable matter itself; but sensation is a later principle, does not take place until birth, when a new economy is set up, in which sensation is called in by the living principle for the support of the whole, beginning first in the stomach by sympathy, and then going on in a series of actions. These compound actions, therefore, cannot take place until sensation takes place ; and it is reasonable to suppose that a child in the womb has no sensation, for it is just as well formed in all its parts without brain as with it, and the nerves are indebted to the brain for their formation.*

* [This statement is incorrect. The nerves may exist without the brain or spinal marrow, which are accessory, not the fundamental parts. The same law obtains in regard to the heart and blood-vessels: and indeed it may be observed generally in regard to the progressive development of the higher animals, that at first they follow the type of inferior animals, but afterwards advance to those which are still higher and higher in the zoological scale. Hunter in the main was well acquainted with this law of development as regards the higher animals, as will appear from the following passage, in which we may remark that he has anticipated many of the leading discoveries on this subject by modern anatomists. The passage occurs in the introduction to the description of the drawings relat- OF THE BRAIN AND NERVES. 59 But the moment a new mode of action takes place, actions arising from sensation must be performed for the support of this ; and an animal must die if these sensations are not produced, which cannot be produced if there is no brain.* Actions arising from the union of the two principles, life and sensation, are extremely evident; being all those actions which constitute a state of mind, or those feelings of the mind from which instinct arises. Sleep.—A singular result of our being possessed of the sensitive principle is sleep. Perfect sleep is an annihilation of the power of present sensation, of the power of thinking, and all traces of the past, or what we call memory. We find that there is, of course, a cessation of all voluntary actions; the will itself is in every respect at perfect rest, and we are at this time, in respect to ourselves, in a state of non-existence. But sleep has its degrees; perhaps in all cases there is a loss of these considerable principles, especially sensation; but the effects of sensation are not always lost, namely, those operations of the mind which produce actions which are very nearly voluntary. During sleep, therefore, the mind may be thinking, which forms what we call dreams; but as our present sensations do not become'directors of those actions which the mind is employed about, no such action takes place as the mind forms to itself. It is even possible to dream when awake ; it is only necessary for the thinking power to take possession of the mind, and to proceed with an action with which the present sensation has nothing to do, so that a person neither sees objects, hears sounds, nor feels anything that touches him; and when the mind ceases to act and sensation returns, we call it a dream. Now whenever the body loses the consciousness of its own existence, it may be called a waking dream, and this is often the case when people are in deep thought. Sleep appears to be to the sensitive what I have already described to take place in the living principle, when I mentioned my own case; but that arose from disease, while sleep is necessary. When both these principles undergo a cessation of their actions it is called a swoon. Here there is a cessation of all actions which naturally arise in the body, but still a capability of having them ing to incubation. " If we were capable" (he says) "of following the progress of increase of the number of the parts of the most pprfect animal, as they first formed in succession, from the very first, to its state of full perfection, we should probably be able to compare it to some one of the incomplete animals themselves, of every order of animals in the creation, being at no stage different from some of those inferior orders; or, in other words, if we were to take a series of animals, from the more imperfect to the perfect, we should probably find an imperfect animal, corresponding with some stage of the most perfect." (Hunt. Cat. Phys. Series, vol. ii. p. 4.) Many other passages might be adduced which evince that Mr. Hunter's extensive acquaintance with comparative anatomy had enabled him to deduce the true principles which regulate the formation of the body and the coexistence of the different systems of parts in the same individual organism.] * [Mr. Hunter must have been aware of many examples of fetuses without brains which have lived for some time after birth. He must here mean the medulla oblongata, without which respiration cannot take place.] 60 HUNTER'S PRINCIPLES OF SURGERY. reproduced, Now in a fainting fit there seems rather a cessation of the actions of sensation, the animal becoming totally insensible to itself; but in a swoon we have this carried further; the cessation takes place not only in the sensitive but in the living principle itself, for we shall have people fall into a trance or swoon, and they shall remain in it without any kind of motion,—respiration, circulation, digestion, and every operation of the body at total rest; and if the disease, or the cause of cessation of that action, should continue a long time, they may lose the power of reproducing this sensation again. Fainting from bleeding, fear, &c, is a swoon in a certain degree, for these principles are diminished, especially the sensitive. Sleep is not only a cessation of voluntary action, but produces cessation of involuntary action of voluntary parts, arising from their diseases, as in St. Vitus's dance, &c. Sleep is of such material consequence to the sensitive principle of the constitution,—namely, sensation, mind, and will,—that it may be said to constitute one third of its duration. As it is only an annihilation of sensation and all its consequences, one might suppose that it was of little consequence to the machine; but it is as essential to it as food. Sleep, or rather a cessation of sensation, thus taking place, while the action of life is going on, shows that there must be a peculiar structure, and a principle arising out of that structure superadded, making a compound which is endued with life; for life for a time can go on without sensation, but cannot always go on without it. Sensation, then, is a fatigue to life; and in proportion to the exertion of sensation, in a given time, the sooner is life wasted. For this reason, when we are in health, sensation stops at proper times; life then appears at ease. This slighter effect of health is often increased preternaturally, as in cases called lethargy.*

* [Dr. Marshall Hall found that the muscular irritability of hybernating animals was greatly increased during their state of torpor. In the same way, sleep, " nature's second best course," seems to be intended to recruit the exhausted irritability of the system after the labours of the day ; and accordingly during the condition of sleep the organs both of animal and vegetative life are in a state of repose, the one completely, the other only partially so. Various causes have been assigned for this state, none of which is completely satisfactory.] OF SUSCEPTIBILITY TO IMPRESSIONS, ETC. 61 CHAPTER VII.

OF SUSCEPTIBILITY OF IMPRESSIONS ; OF STIMULI ; OF DISPOSITIONS OF THE BODY J OF HABIT AND CUSTOM.

Difference between impressions on animate and inanimate matter; of internal susceptibilities.—Of stimuli;—carried too far they become irritants ;—animals susceptible of stimuli at one time and not at another.—Of dispositions of the body ;—less well understood than those of the mind;—in health arising from impression;—in disease without it.—Of dispositions in the mind;—their ultimate effects are on the body.—Of dispositions of the body compared with the preceding;—both compared with the actions of machines.—Want of balance betwixt the parts of animals ;—parts weakest when at a distance from the sources of power;—why.—Of the memory of impressions;—to be found in the body as well as the mind ;—example.—Of the effects of repetition of natural actions.—Definition of habit and custom.—Of custom;—lessened effects from repetition of impression ;—increased effects.

Every species of matter, whether inanimate or animate, is capable of impressions, and the effects of the impressions, are according to the nature of the impression and the part impressed. All matter is not capable of acting or reacting according to the impression, which passiveness belongs to inanimate matter, though not to all. A piece of dough receives impressions, but seems chiefly passive, not having the power of reacting, and making but little resistance. Elastic bodies receive impressions, which they restore in a contrary direction, producing ultimately various effects, which I have said are the soul or life of mechanism. In animal bodies the effects of impression are more various and complicated than in inanimate matter, because the most simple animal is more various and complicated in its susceptibilities of impression, and of course more complicated in its dispositions for action. In inanimate matter there are no actions within itself excepting the disposition to reinstate itself, as in elasticity; therefore impressions are not rising up within itself, in consequence of its own actions, as in animals, so as to produce consequent dispositions and actions, unless we could conceive that chemical and fermentative operations were of this kind. But animal matter having internal actions, these actions are producing impressions which are forming dispositions to action in the parts impressed; and, secondly, it is capable of being acted upon or impressed by common inanimate matter, in both which cases the impressions will be according to the nature of the impressions and part impressed conjoined. When a man is so affected as to feel within himself that he cannot live, which is very common, it arises from the mind being made acquainted with the state of the body; the living powers are be- 6 62 HUNTER'S PRINCIPLES OF SURGERY. come weak, inactive, &c, and the nerves are communicating the intelligence. Accordingly, their actions are expressive of the extinction of life going on, and the action of brain is expressive of such actions of the nerves; and as death is a something we know takes place, and this sensation of ours is not such as we feel in health, we conclude, from an habitual species of reasoning, that we cannot live, and we are often not deceived. This effect is often so quick that it may exceed the sensation of it, or at least may hardly afford us time to communicate these sensations to others. The internal susceptibilities, with the consequent impressions and dispositions, are, first, of want, and, second, of repletion; and all the other internal operations of the machine arise naturally from these two, especially repletion, as digestion, circulation, respiration, secretion, the intercourse of the sexes, &c. But the first movement of these actions appears to require the impression of external matter, the powers of digestion being excited by food being thrown into the stomach, in consequence of which circulation, respiration, secretion, &c, all follow, arising out of the internal operations of the machine ; all which have nothing to do with the sensitive principle, but are wholly dependent on the living principle. The desire of food, or susceptibility of the stomach to digest it, arises not from external objects, but from its own organization. The second kind, susceptibility of external impressions, affects principally the sensitive principle, but may also affect the living principle, as in medicines. These are called stimuli; and when both principles are affected they may be said to have the management of the machine.* Impression or stimulus, produces a disposition to act, or rather action may or may not take place. But all impressions, either on the living or sensitive principle, are not stimuli; some go beyond stimulus, and become irritants ;f and other impressions are from their nature not stimulants, but produce a disagreeable impression either to the mind or body, and are also irritants. Stimuli—An animal, I have observed, is susceptible of impres-

* [It is impossible to avoid remarking here the similarity of this view of Hunter's to Bichal's division into organic and animal actions.] | [It may safely be said that almost all stimuli, when applied in excess, operate as irritants, and, if carried to their utmost point, as direct sedatives. Thus, electricity, which in a moderate degree irritates the system or rouses it to an unusual degree of action, in a concentrated form immediately extinguishes life. Cold and heat have the same effects, and so have most other stimulants. The same remark applies to those stimuli which in a healthy state proceed from the mind and produce agreeable impressions ; as, for instance, joy, which may be exalted to ecstacy, and so occasion sudden death. It is probable that the same principle obtains in regard to the internal economy, and that those powerful sympathies which are the result of disease are many of them merely to be regarded as exaltations of natural impressions primarily subsisting between the different parts, which may be carried to any conceivable extent, so as to produce increased action, pain, or an entire destruction of the function. A different class of affections, will, on the other hand, arise from a deficiency in these impressions.] OF SUSCEPTIBILITY TO IMPRESSIONS, ETC. 63 sions; which impressions, I shall now observe, are to become causes either of immediate or remote disposition to action, either in the part impressed, or some other by sympathy. These impressions, which excite or increase the disposition, are called stimuli; therefore we may say that a part is stimulated, or such an application, substance, or object is a stimulus ; and a part either readily increased in action by impression, or brought into action, we say is very susceptible of stimuli. I could wish we had some one word expressive of this condition of the part stimulated, as stimulable, and also of the stimulus, as stimulative, to answer to irritable, sensitive, &c. An impression which becomes a stimulus by sympathy may have been carried so far as to have been an irritator of the part to which it was applied, as a mote in the eye irritates the tunica conjunctiva, which irritation acts only as a stimulus to the lachrymal gland, for this gland can only act by sympathy. The power of a stimulus must be according to the nature of the stimulus and of the part jointly, for as almost every part of a body has a peculiarity in its mode of action, every part must have its peculiar stimulus. An animal is so constructed as to have its parts susceptible of stimuli at one time and not at another. An animal has a power of improving its parts so as to make them susceptible of such stimuli as are adapted to the disposition of the parts; for instance, an animal improves all those parts peculiar to the sexes. When those parts are perfect, which is called the age of puberty, they stimulate the mind and various other parts connected with that, giving rise to the passion of love or the appetite of lust. On the other hand, want becomes the cause of impression: a part becomes susceptible of such want, so that the ultimate effect or stimulus is completely produced, and an appetite arising from such stimulus takes place. Thus, the stomach when empty is susceptible of the stimulus of hunger. This kind of stimulus may be carried so far as to excite a diseased action, and must then be considered as an irritant. Of Dispositions of the Body.—It may be difficult to define a disposition of the body, but that the body has dispositions is undeniable ; and without knowing this, and therefore coming at or endeavouring to come at the knowledge of these dispositions of the body, a man must be a very confined surgeon in his practice. But the term disposition is more commonly applied to the mind than the body. In the mind it is more easily comprehended, because the mind has the power of investigating its own feelings or dispositions, also the power of communicating them, by means of the body, to the minds of others, so as to be understood or felt by those minds. Every man has felt perhaps every disposition that can arise in the human mind, and is therefore perfectly sensible of those dispositions when they occur in others. But in the present inquiry the mind has no intelligence of the feelings or dispositions of the body, 64 HUNTER'S PRINCIPLES OF SURGERY. and is obliged to compare the effects of the one with those of the other, and where they are similar to suppose that the causes are also similar. A disposition either in the mind or body, when in health, always arises from some impression; but as both mind and body are capable of seemingly spontaneous actions, these may arise from diseased dispositions in both, producing madness in one case and strong disease in the other. As disposition may arise in consequence of some impression, it is capable of being destroyed by a counter-impression, which in disease is the method of cure that will be called specific. Many dispositions wear themselves out, or are such as the body or part cannot go on with. A disposition is different from a visible action, yet it is possible it may be itself an action. If we compare the actions of the body with those of the mind (which is comparing from analogy, and perhaps the only mode we have,) we shall gain a pretty good notion of them. A disposition of the mind, then, certainly arises either from some action of the brain, or a certain position of the parts of the brain takes place, giving them an inclination to action. But this action, or the position which produces the inclination to action, we know nothing of; it is only a sensation of the mind, or rather a consciousness of the mind of such inclination, which sensation or consciousness, is different from the sensation of the brain, arising from other actions of this viscus : and also knowing that such action of the brain as produces such sensation in the mind, is endeavouring to set other parts of the body into action which may be called voluntary, or rather actions in voluntary parts ; and that when such actions of the brain have taken place, such dispositions of the brain are lost; I say, knowing so much, we may, knowing from analogy, form some idea of bodily dispositions. But the dispositions of the body appear to differ in this respect from those of the brain, that in the brain there is only the disposition, the ultimate or consequent action taking place in the body. But this is, perhaps, because we are not much acquainted with the immediate effects of the disposition in the brain, being led away by the visible actions which take place in the body. To explain this, let us suppose that I have an impression made on my body in such a manner that my sensitive principle is sensible of it; if, for instance, a man gives me a knock on the head that makes me angry, I form a disposition from that for resenting it: that dispoposition in my mind produces an action in my brain which forms a peculiar state of the mind, which is anger. If it was an action of some other kind, it might be affection or gratitude. The brain can do nothing by way of retaliation, whether it be gratitude or revenge which directs, but to set parts of the body to work. Having received a blow on my head, the disposition in my brain to produce the action of revenge sets my hands to work to give my enemy another OF SUSCEPTIBILITY TO IMPRESSIONS, ETC. 65 blow, and then the disposition is at an end. So that whenever the action has taken place, the disposition is gone.* The ultimate effect is made sensible to us, and we are apt to imagine that it is the immediate act of the disposition of the brain; but it is only that the immediate action which took place in the brain made other parts of the body act secondarily, so that three actions are necessary to the ultimate effect; but they are not all three actions of the brain. There is, 1st, the action which produces the disposition: 2d, the action of the nerves in consequence of the disposition: 3d, the action of the voluntary muscles in consequence of the action in the nerves; but only the two first actions belong to the brain.t Let us see how far this disposition and consequent action of the brain correspond with the dispositions of the body and the actions arising in consequence of these dispositions. If on any part of an animal an impression is made, a disposition is formed suitable to that impression, which is the first; and an action in the same part suitable to that disposition may take place, which is the second, and is the ultimate; but if a sympathetic action takes place, it becomes somewhat similar to the ultimate effect on the body, arising from a disposition in the brain. We may, with great propriety, compare the disposition and action of either the brain or the body with the disposition or action of an elastic body. An elastic body, when acted on, (which is similar to an impression made on the body,) acquires a disposition or inclinar tion, which, if allowed, will produce action in all parts of the elastic body, which destroys the disposition. The disposition to action, and the action, are two very different things in themselves, even in the elastic body: when the elastic body has performed its action, it remains at rest until acted upon again; but it always acquires action to destroy disposition. We must make a material distinction between a disposition and an action in diseases, for what will cure an action will have no effect on a disposition. Every machine is composed of very different parts, yet all tend to some ultimate effect. Every machine, whether natural, as an animal body, or constructed by art, however simple it may be, yet is always composed of more parts than one; and it must be observed, that no two parts have the same action, although all are tending even in the most complicated, to produce some one ultimate effect,

* [The disposition does not cease because the action has taken place, but because a new feeling, that of gratified revenge, has arisen in the mind, and taken the place of the previous disposition. Had the blow of retaliation missed its aim, the disposition would have continued, notwithstanding the action had taken place, until a second and more effectual one had been given, This mode of reasoning from metaphysics and false analogy is extremely unsatisfactory, although K must be admitted, that many striking analogies exist between the powers and actions of the mind and those of the body, which Hunter seems to have studied with attention, and of which he has adduced some apt examples.] f [Or rather to the sensitive principle, which he supposed to be 6eated in the whole of the nervous system.] 6* 66 HUNTER'S PRINCIPLES OF SURGERY. For instance, some machines of art are intended for the division of time, as a clock, which may be so simple as to perform that effect by one wheel, the effect being expressed by an index. Some, again, are much more complicated, all the parts, however, being employed to the same ultimate effect, namely, the movement of this index, which expresses the ultimate effect; and the different parts composing the clock may be called organs. So it is with natural machines ; some animals are so simple as to have apparently but one operation, and that is support, and these may be called one organ. Others are complicated, being composed of different parts, whose actions and effects appear complete in themselves, as the action of a kidney, a liver, &c.; yet all combine to produce an ultimate effect in the machine, namely, the preservation and continuance of the species. To produce the ultimate effect in any machine, there must be a succession of actions, one naturally arising out of another, each part taking on the action peculiar to itself; the preceding action being always the stimulus to the next succeeding one ; and thus the parts go on acting in regular succession until the ultimate effect is produced, and then the whole is at rest until stimulated into action again. In some parts this is almost immediately, as in the heart, organs of respiration, &c.; thus, when the heart has thrown out its blood, it has done its business; when we inspire and expire, the organs of respiration have done their business, but there is a necessity for a recurrence of the operation again, and so immediately that it seems almost constant. But in others there is a greater distance of time before the action is renewed, as in hunger, evacuation of the faeces, urine, &c. An animal body so constructed, gives us an idea of perfection, for as each part has its particular appointment, one should naturally expect equality or powers suitable to these appointments would be found through the whole. But this certainly is not the case, at least in the more complicated animals, whatever it may be in the more imperfect and simple. We find this in the more perfect, where life depends for support in the action of some one part, as the heart; also where many actions of the animal depend on the powers of another part, as the voluntary actions on the brain ; and not only the simple voluntary actions of the body depend on this viscus, but their real strength depends on it, for whenever the power of the brain is taken off, they waste; and this wasting does not arise from the brain supplying these parts with nourishment, and that being now cut off they lose their future support, but it arises from want of necessity to keep these parts in a state fit for action* wrhen action cannot take place, because the will cannot

* [If the exercise of every part is its natural stimulus to perfection, as it certainly is, by exciting the natural actions of which every part is capable, then the want of exercise is the cause of this wasting. The same effect would equally be produced, although the parts should be supposed perfectly capable of executing their proper functions if called upon to do so. The stomach that has lonor fasted, OF SUSCEPTIBILITY TO IMPRESSIONS, ETC. 67 now stimulate them to action; and the same thing takes place in a proportionate degree when a joint is simply rendered, either wholly or in part, unfit for motion, where no injury has been done to the nerves. Hence it must appear, that as the power of support is in one part of the machine, and the power of many actions in another part of the machine, it is possible that all parts of the body may not be equally served by the first, namely, the heart; nor equally influenced by the second, namely, the brain; and we do find that the more distant parts from these sources of power are the weakest. This, perhaps, is better illustrated in disease than by any actions of health. We may just observe, that all the vital parts are near the one, and all the acute sensations near the other. In disease we see a mortification arising in the extremities more than in the other parts, and more especially if the person is tall, so that the heart is not capable of propelling the support of life to those distant parts in such a state of the constitution. How far the blood may lose its power of nourishment before it reaches the extremities, I will not say. If our acute sensations are near to the brain, it is reasonable to suppose that proximity of parts adds to the power of the nerves in communicating sensation; if so, it is reasonable to suppose that proximity of parts will also add to that power which the brain has over the actions of voluntary parts by means of the nerves. On Habit and Custom.—Memory, or recollection of past impressions, has, I believe, principally been applied to, or supposed to be an attribute of, the mind only; but we know that every part endued with life is susceptible of impressions, and also that they are capable of running into the same action without the immediate impressions being repeated. Habits arise from this principle of repetition of, or becoming accustomed to, any impression, and the same thin* exactly takes place in the mind. The memory of the body is of much shorter duration than that of the mind. The mind not only goes more readily into action the second time of an impression, though a considerable distance of time has taken place since it went into the same action before, but seems to take up the action with more ease, from merely collateral causes, from a recollection of the similarity, or often without any possible recollection whatever, as if the actions, in consequence of the former impression, were taking place in the brain again. This does not appear to be so much the case with the memory of the body, tor this only arises from immediate impression, but goes into action a second time more readily than at first. Possibly, however, the action arising from the first impression may be repeated from some

or the eye which has long been deprived of light, lose the power of performing their ordinary functions just in the same manner that a joint which has ong been confined in one position loses its suppleness and strength, and the) muscles waste. This tendency on the part of our author to suppose a sort of'intelligent^ un derstanding subsisting among the different parts of the body has been already ad verted to.] , 68 HUNTER'S PRINCIPLES OF SURGERY. collateral or similar impression to the first; if so, it comes very near to that of the mind, though not so strong. A gentleman rubbed in mercurial ointment for the reduction of two buboes; he had only used it a few times when it affected his Constitution so much that he was obliged to leave it off: he became feverish, the fever being of the hectic kind, with a small quick pulse, debility, loss of appetite, no sleep, and night sweats. He took the bark, with James's powder. As the effects of the mercury went off, and his buboes were advancing, it was necessary to have recourse to mercury again; he now rubbed in a considerable quantity without its having the least effect on his constitution or mouth; but the buboes spreading, made me order it to be left off again, and they were opened. He had recourse to the ointment the third time without its producing any disagreeable effect. The buboes took on a healing disposition, but then became stationary. I ordered him to leave off the ointment, to go to the sea, and bathe, and then they began again to heal. In about three weeks it was thought necessary to rub in again : when he began, it almost immediately affected his mouth very violently ; he left it off till his mouth was a little better, when he began for the fifth time, and it had not so much effect, and he was able to pursue the mercury. Now in this case he had lost the mercurial habit during the time he was at the sea, the parts had forgotten the mercury altogether, and the mercury coming on such a state of constitution, produced the same effect as it would have done if he had not taken mercury. So that the body had, as it were, lost the remembrance of the effect of the mercury on it in so short a time; but the mind would not have lost it. Custom is with me the negative of habit; by custom comes an insensibility to impression, the impression diminishing although the cause is the same, and the parts becoming more and more at rest; whereas from habit there comes an increased facility to go into action, as also an acquired perfection in the action itself, the impression continuing the same though the cause is diminishing. These may be reckoned as secondary principles in an animal, and produce two very opposite effects, both according to their modes of impression. Habit is the continuance of actions we have been accustomed to produce, without any immediate assistance, or even continuance, of the first cause, as a body set in motion continues to move after the cause of motion has ceased to act. Custom arises from external impressions, either in the mind or body, and is of two kinds, one when, the cause continuing, the impressions and consequently the actions, are diminished, the parts becoming habituated to the impression. We shall see the effect of this in our applications. If we apply a medicine to a sore, Which shall affect it in one way or another, (it is immaterial which for the principle, but we will suppose it heals,) from becoming accustomed to that application, it shall lose the impression, and shall at last do OF SUSCEPTIBILITY TO IMPRESSIONS, ETC. 69

nothing; therefore you will be obliged to make the application more stimulating, more active, or change it for something else. It is exactly so with the mind; if a man goes into a strange place he is affected by the new objects about it; the next time he goes he is less struck; the third time less, till at last, when he goes into the place he can hardly perceive anything strange in it. These very different effects arise from a difference in the degree of impression resulting from the state of the mind or body at the time. In the first instance, if the impression or cause be very slight, so as hardly either to alarm the part or the constitution, they will get familiar with it, and will become insensible to it; a ring on the finger, the use of snuff, our very clothes, and physic itself are striking and daily instances of this. The habit of insensibility will soon be formed if the sensations of the mind and body be not very acute. If the first impression be violent, and such as produces considerable effect, it is not necessary that the same degree of violence should be inflicted to produce a similar effect the second time. One can easily imagine that these impressions may be continued until the parts continue to act without the impression, which would then become habit. If a dose of an emetic be given, which affects the stomach much, the same quantity is not necessary a second time to produce the same effect; the second must be given, however, before the stomach has lost the impression of the first perfectly.* The same effect is produced on the mind as on the body, for whatever has made but a slight impression, soon wears out, and we think no more upon it. On the other hand, if an animal has met with anything that has affected its mind much, as fear, &c, it is not necessary for the object to appear in the same manner to produce a similar effect. Those effects will be more or less, according to the state of the body or mind at the time of the first affection; the more irritable or the more ready it is to fall into the first action at the time, the more readily will it take it up the second time, although it may not be particularly irritable or susceptible of this particular action. Habit.—A habit of acting arises from a repetition of acting, which repetition of acting is custom, and which becomes the cause of the continuance of the same action. So that custom is always prior to habit, or, as it were, forms habit, which may be ranked as one of the secondary principles in the machine.

* [This arises partly from habit and partly from the fact that the emetic has produced an irritable state of the stomach, which renders it more susceptible of the action of any irritant. It would appear that mere impressions, or the passive part of habits (called by Mr. Hunter custom), always diminish in intensity by repetition, but that the actions or thoughts that are put in train by those impressions recur more easily the oftener the impressions are repeated. The reader who is desirous of pursuing this subject is referred to Bishop Butler's admirable treatise on the Analogy of Natural and Revealed Religion, Part I. Chap. V., a book which, like Hunter's Treatise on Inflammation, was the product of upwards of twenty years' labour, and is stamped in every page with characters of the most profound genius.] 70 HUNTER'S PRINCIPLES OF SURGERY. The first action being produced by a disposition in, or force upon, the part, this being repeated or continued a sufficient length of time, the action at length goes on, when that original disposition or force is gone, until some other power counteracts it, or it wears itself out. The more we have been in the habit of thinking on any object, the more readily does the train of thinking relating to that object occur. This princip'al in the animal is similar to the vis inerticn in matter, for by it a motion begun is continued, and their remaining at rest is from the same cause. This principle becomes the cause of the actions of the mind; it does not allow men to think differently from what they have been accustomed to think. Men in general go through life with the same modes of thinking, and thus it becomes a cause either of the retardation or improvement of the understanding. It retards improvement, because it gets the better of even present sensations, and does not allow men to wander into novelty. It promotes improvement, because it makes men perfect in what they have been long employed about. CHAPTER VIII.

The principle of heat a great principle of action in nature;—nature of, unknown; —opposed to cold ;—unequal distribution of on the earth ;—measures of sensible heat;—absolute heat of bodies, unknown;—of the sensation of heat;— destructive when in a high degree, as is cold.—Natural heat of animals capable of diminution without loss of life;—certain functions first cease ;—propagation of the species first;—digestion in some animals, as reptiles.—All animals endowed with heat, but in different degrees ;—erroneous notions of its causes ; cases in which the function was remarkably deranged ;—experiments, showing the power of animals to generate heat in proportion to the necessity;—order of cessation of functions from cold;—diminution of heat during sleep.—Experiments on hedgehogs.—Heat of lower animals varying with temperature of the air.—Standard heat of higher animals not exact.—Experiments to ascertain whether cold acts as a stimulus to the production of heat.—Resistance to external heat;—experiments;—those by Fordyce.—Observations on animals having a standard heat;—differences in the capability of different animals to produce heat.—On differences of climate resulting from temperature;—other causes also act.

The principle of heat is one of the first principles of action in nature; it is that which unlocks matter, and allows it to act according to its natural properties, or according to its combinations. It may be even said to compel matter to action. But that idea arose, I imagine, more from the effects which extreme heat has both on our sensations, and its immediate effects on our bodies seeming to produce a species of violence, for we do not annex this idea to moderate heat, although moderate and immoderate heat act on the same principle OF THE HEAT OF ANIMALS. 71 of putting matter in such a position that certain actions in the matter must take place, all which arises from the nature of the part heated. How far it is an active principle is not easily ascertained, though we must allow it has every appearance of being one. The term heat meant originally simple sensation, arising from a property of matter capable of producing that sensation, which is only an effect of that property. But philosophers having inquired into the causes and effects of this matter, have, from a poverty of language, applied the word which was at first only expressive of a quality to the thing itself, so that by heat now is also meant the matter of heat abstracted from the sensation which it occasions.* This is so much the case, that Dr. Blackt makes use of the term latent heat to signify that heat which a body contains without imparting it to the senses, as we might call the water which goes into the formation of salt latent water: in other words, that water which the salt contains without losing its solidity. It has been much disputed whether heat is matter, or only a property of matter. If it is simply matter, then, wherever there is heat there must be that matter present. If heat is a property of matter, there must be both matter and property present. If heat is only an action in a particular matter, then there is that matter with its action, as also the body which throws this matter into the action.^ Heat and cold are opposite principles, and cannot inhabit the same place.§ They occupy different parts of the globe, and in some places alternately ; these, therefore, are subject to the variations of temperature, which cause varieties of climate. These will be further spoken of hereafter. Heat, although not equally distributed all over the globe, yet

* [The sense of this inconvenience has given rise to the general use of the term caloric for the agent which produces the sensation of heat.] | [In connexion with the name of Dr. Black, we may mention that it was not until this able philosopher had completed his train of researches on the subject of heat that the true theory of respiration began to be understood, or the connexion which subsisted between this function and the production of animal heat. Previous to this time the lungs were considered merely as the agent for cooling the blood.] X [Whether heat consists of a highly attenuated subtle matter which pervades all things, or of a vibration among the atoms of matter, has not yet been decided. Its leading feature is evinced in the repulsion which it produces among the particles of matter, in which respect it is the proper antagonizing force to attraction. Whatever it is, we do not know anything of the principle itself, or of the manner in which it produces its effects. The subject of animal heat occupied a great deal of Mr. Hunter's attention, in consequence of which he made it the subject of two express papers in the Philosophical Transactions, besides recurring to it again very fully in the Treatises on Inflammation and the Animal OEconomy. The reader is ieferred to these works in the third and fourth volumes for fuller information.] § [Cold was formerly thought by philosophers to be a positive principle, like heat, instead of a mere negation or absence of heat, as it is at present almost, if not quite, universally considered. It is in the former view that Mr. Hunter speaks of it.] 72 HUNTERS PRINCIPLES OF SURGERY. exists in such a degree as to pervade all matter, and is therefore to be found in some proportion everywhere. Heat destroys attractions of all kinds, by which means it becomes the principle of fluidity, and consequently the reverse of the cohesive attraction, or principle of solidity. By means of this effect, motion is allowed to take place among the particles of matter. We have no other idea respecting the variations of heat, except as regards quantity. The quantity of heat has always been estimated by some visible effects, at first probably by our sensations alone, but afterwards by its effects on the expansion of bodies, especially of metals,* all of which is called sensible heat. But it has been discovered lately that many bodies retain more heat than can be made sensible by any of the commonly constructed instruments; therefore a body may have the matter of heat in it without its producing any sensible effects. Hence heat has now been divided by some into sensible and absolute heat. It may be possible that many bodies may have their whole heat made sensible: if so, then their sensible and absolute heat are the same. But it is most probable that the absolute heat of a body can never be known, for the measure of the quantities of heat from every experiment is always by sensible heat, which can never be a proof of the absolute heat in a body. The real increase of heat must alter the position of parts so as to produce the sensation called heat; and as this heat is diminished, the texture or position of the parts is altered the contrary way, which, when carried to a certain degree, becomes the cause of the sensation of cold. Now these sensations could not take place without a real increase or decrease of heat in the parts. When heat is applied to the skin, it becomes hot in some degree, according to the application. This may be carried so far as actually to burn the living parts. On the contrary, in a cold atmosphere a man's hand shall become so cold as to lose the sensation of cold altogether, and change for that of pain.t

* [It has lately been discovered that minute variations of temperature, utterly inappreciable by the ordinary instruments founded on the principle of expansion, may be rendered evident and estimated by means of electro-magnetical currents, which are found to traverse certain arrangements of the metals when unequally heated. The degree in which the needle deflects from its mean position indicates the quantity of caloric which has entered the heated body, and may be measured by an index of degrees.] f [It is improbable that the sense of heat and cold depends simply on an "alteration in the [texture or] position of the parts," for if this were the case the same temperature, by inducing the same condition of parts, should always produce the same sensation, although it is well known that this is far from being the case. What to one hand, just removed from a vessel of hot water, feels very cold, shall feel very hot to the other hand just removed from a vessel of cold water; or a part shall feel hot or cold when the reverse of these states is actually present. The sense of change, or the intensity of the impression, is estimated in relation to the previous state rather than to its absolute quantity, or else depenJ9 on some peculiar and morbid condition of tqe sentient organ. Thus, the eye which has long been secluded from light is oppressively affected by the common OF THE HEAT OF ANIMALS. 73 Real heat and cold may be carried so far as to alter the texture of parts on which the actions of life depend. Nature has allowed the heat of most animals to come much lower than the heat necessary for performing all their natural functions. This is most so in the more imperfect animals, although it exists in a considerable degree in those possessed of a better regulated standard of heat, as the most perfect. This answers the wisest purposes, for by allowing the heat to come to that degree in which many actions are suspended, or annihilated, the state of the animal is adapted to the state of the atmosphere, which is such as would render the effects of those actions unnecessary or of no effect. The first action that is suspended is the propagation of the species ; for if birds were to hatch, or animals to bring forth their young, in winter, there would soon be an end to propagation in the temperate and frigid zone, as animals in general only breed once a year. Cold also annihilates the powers of digestion in all those animals whose food is rendered impossible to be procured in the winter, and which have not power of emigration, such as frogs, lizards, snakes, bats, hedgehogs, &c. The power of generating heat was the first considered; the possibility of generating cold being hardly suspected, because most people who made observations on this subject lived in an atmosphere colder than their own body. They observed, that in almost all animals there was a standard of heat, which in common language has been called blood heat. However, they extended their observations a little further, and called a certain number of animals the cold-blooded animals, but made no experiments either to ascertain the effects or the principle on which they depended. If we examine any class of animals, we shall find them, more or less, endowed with this principle, though varying from one another very materially in this respect. The heat of the human body being always considerable, even in the coldest climate, it has necessarily attracted a good deal of the attention of philosophers and physiolo gists, and various have been the opinions which they have formed respecting its cause. Friction being a cause of the production of heat in many bodies, was supposed to be the cause of heat in animals, especially, too, as they thought it could be easily explained on this principle, for they observed there was sufficient motion in the body for such an effect, which motion was principally that of the blood. They calculated the size of the internal surfaces of the arteries, which increases as

light of day; and the same thing may be asserted of stimulants and their effects universally. It is a singular fact that excessive cold should produce effects very similar to those produced by excessive heat. Frozen mercury, for instance, occasions a sensation of burning, and destroys the life of the part which touches it if the contact is prolonged only a few seconds. 7 74 HUNTER'S PRINCIPLES OF SURGERY. they divide. They calculated the size and number of the red globules; all of which furnished an amazing extent of surface for friction; and when they calculated the velocity of the blood moving on this extent of surface, as also of the globules on one another, they thought they saw a sufficient cause for the heat of the body, especially as they saw that when this motion was increased, as in fevers, the heat was to appearance greater. But we may say at the same time, that they did not see the objections to this theory, which are many. Dr. Stevenson* observed, that there was another cause for the production of heat besides friction, viz. fermentation, and on this principle he accounted for animal heat. But the fermentation of animal substances does not produce heat. The superstructure built on the foundation that the friction, from the motion of the blood, is the cause of animal heat, falls immediately to the ground on the observation that fluids have no power of generating heat; nor have two solids, if kept asunder by the intervention of a fluid of any kind. If this had not been a fact, still friction probably would not have accounted for all the variety in the production of animal heat. Nor could the principle of fermentation account for all the phenomena which attend the heat of animals; therefore some other principle must be referred to as the cause. It being discovered that the absolute heat of bodies differs very much in different substances, and perhaps in the same substances differently combined, it was thought that this would account for the production and continuation of animal heat. It is supposed that the air which we inspire has much more absolute heat than the same air has when we expire it, and that the superabundant heat of the inspired air is given to the animal. But this chemical method of accounting for heat will not account for all the varieties in the heat of animals at different times, especially in disease, when the breathing does not equally vary or correspond with the heat of the animal. A remarkable case fell under my observation of a gentleman who was taken with an apoplectic fit. He lay insensible in bed, covered with the blankets. I found his whole body would become extremely cold in every part, and continue so some time, and in a short time would become extremely hot. While this was going on, several hours alternately, there was no sensible alteration either in the pulse or the breathing. A man fell from his horse, and pitched on his head, and produced all the symptoms of a violent injury. There was concussion and perhaps extravasation of blood, but no fracture could be seen. The pulse was at first 120°, but came to 100, and sometimes to 90, and * [Edin. Med. Essays, vol. y. Part II. p. 806, et seq. These Can only be regarded as specimens of the opinions and modes of reasoning adopted by the mechanical and chemical physiologists of the last and the preceding centuries, to the subversion of which the efforts of Hunter, united with those of Haller, Stahl, and Cullen, mainly contributed.] THE HEAT OF ANIMALS. 75 was strong, full, and rather hard. He was very hot in the skin, but breathed remarkably slow, only half the common frequency. His breathing, pulse, and heat therefore did not correspond with this theory of heat. February, 1781.—A boy about three years old appeared not quite so well as common, being attacked with a kind of shortness of breathing in the night. It had become exceedingly oppressive about five o'clock on Sunday morning, so difficult that he appeared dying for want of breath. In this state he lay till ten o'clock when I saw him. He was breathing so slowly that I thought every breath would be his last, about two and a half inspirations, or even less, in a minute. (The common rate of breathing in such a boy is about thirty inspirations in a minute, and about twenty in a man.) When he drew his breath it was with a jerk; but his expiration was extremely slow, generally continuing through five seconds. I often could not distinguish the pulse, at other times it was very manifest, although very faint and slow, not more than sixty. On tying up the arm the vein did not rise in the least, so that the blood did not go its round. His eyes were turned under the upper eyelid ; while his body had a purple cast, especially the lips, which is easily accounted for,—it was owing to the blood not getting the scarlet red in its passage through the lungs, and whatever it might get there was lost in its slow motion through the arteries of the body. He had a fine warmth on the skin all over the body, although in a room without a fire, not covered with more clothes than common in the month of February, with snow falling at noon. Here it cannot be said that the heat of the body, which was neither great nor deficient, could arise from the constant supply furnished by respiration. It appears from the account given in the Philosophical Transactions of the experiments made in the heated room, under the direction of Dr. George Fordyce, that Dr. Cullen long ago suggested many arguments to show thaf life itself had a power of generating heat, independently of any common mechanical or chemical means; though we may observe, that the experiments here related only tend to show the power of producing cold, which they effectually do. I own I had formed an opinion on this subject. I rather supposed that animal heat was owing to some decomposition going on in the body, and in pretty regular progression, though not the process of fermentation. In consequence of an experiment made on two carp, to explain another principle in the animal economy, (where every common action was meant to be wholly suppressed, or so far suppressed as to render them incapable of producing heat,) I found an effect produced while the animals were under the experiment which I did not suspect. I began, in consequence, to suspect some other cause of heat than the common or natural actions of an animal; for during the experiment I observed a remarkable reproduction of heat taking 76 HUNTER'S PRINCIPLES OF SURGERY. place in these two animals. Until this time I had not an idea that there was a possibility of calling the principle forth, or that cold could excite it. Experiment. In the year 1766 two carp were put into a glass vessel with common river water, and the vessel was put into a freezing-mixture. The water surrounding the fish froze very rapidly on the inside of the glass all round. When the freezingprocess approached the fish it became, as it were, stationary ; and the remaining water not freezing fast enough, in order to make it freeze sooner, I put in as much cold snow as made the whole thick. The snow round the carp melted. I put in more snow, which melted also. This was repeated several times, till I grew tired, and I left them covered up to freeze by the joint operation of the mixture and the atmosphere. After having exhausted the whole power of life in the production of heat, they froze; but that life was gone could not be known till we thawed the animals, which was done very gradually. But with their flexibility they did not recover action, so that, they were really dead. Till this time I had imagined that it might be possible to prolong life to any period by freezing a person in the frigid zone, as I thought all action and waste would cease until the body was thawed. I thought that if a man would give up the last ten years of his life to this kind of alternate oblivion and action, it might be prolonged to a thousand years: and by getting himself thawed every hundred years, he might learn what had happened during his frozen condition. Like other schemers, I thought I should make my fortune by it; but this experiment undeceived me.* This experiment laid the basis of many of my future conjectures on animal heat. I think we may observe in the common occurrences of life that for the actions of an animal a certain quantity of heat is necessary; and this quantity I find to be in some degree according to those actions, the greatest degree of heat being always wanted for the least essential action in every order of animals. However, every order of animals in general requires a heat peculiar to itself, though not always so, some admitting of a much greater variety than others even of the same order, as in the insect tribe. The actions of an animal may be placed in the following order with respect to its heat, which is the inverse order to that of their immediate use in the machine. Propagation first; digestion; sensation, in which maybe included wakefulness ; secretion ; circulation; each requiring its degree of heat for complete action. Propagation * [Blumenbach observes that the pupa? of many insects are in winter so thoroughly frozen as to ring like glass or icicles when allowed to drop on the ground, and yet without any injury to the torpid animal within. "The eggs of silkworms and butterflies hatch after exposure to a cold of 24° below zero. On the other hand, insects may be frozen repeatedly, and recovered as soon as thawed." (Elliotson's Physiology, p. 247.) This faculty of enduring cold is infinitely less surprising than that referred to by the last-mentioned author, which allows beetles and other insects to survive being boiled. See note.] OF THE HEAT OF ANIMALS. 77 requires the greatest, digestion may be carried on with a degree less, secretion in two degrees less than propagation, and so on. In the insect tribe there is a difference between a bee and a wasp and many flies. A bee at all times requires a heat above 90 (?) degrees* to support life with ease, while a wasp can allow its heat to vary with the atmosphere without losing life. When the external heat is so much diminished that it does not assist the natural powers of an animal, and it is obliged to vary its proper standard and become colder, then many of the actions are either lessened or totally suspended, not being necessary: generation is suspended, and insensibility takes place, commonly called sleep ; but it is not sleep. Sleep is an effect which takes place in all degrees of heat and cold, though when a man is asleep he is colder than when he is awake, and I find in general the difference is about 1§ degree, sometimes less.f This difference in the degree of heat between sleeping and waking is not the cause of sleep but the effect; for many diseases produce a much greater degree of cold in an animal, without any tendency to sleep. Besides many of the operations of perfect health are going on in the time of natural sleep, at least in the perfect animals, as digestion, secretion, &c, while none of these operations are going on in the tribes called sleepers during their torpid state.}: In these animals, where a great many actions are suspended, it appears an effect arising from a certain degree of cold acting as a sedative. Now this degree of cold in some cases seems to act as a stimulant ; the animal powers are roused to action for self-preservation. It is probable that most animals are under the influence of cold, and that every order has its degree of cold in which many of their actions can be suspended In some countries, where there is summer and winter, there are some animals whose actions are suspended during the winter.

* [Hunter found the thermometer rise to 93° or 98° in a hive of bees in spring; to 104° in summer; to 82° when the air was at 40°, and to 73° in winter. (See his Paper on Bees in Vol. IV.)] f [There is the same close relation between the ordinary sleep of animals in general and the ordinary sleep of hybernating animals, as there is between this last and absolute torpor. In the 1st, the respiration is diminished and the temperature lessened 1^°; in the 2d, the respiration is still further diminished, and the temperature reduced to within a few degrees of the external medium; and in the 3d, the respiration is altogether suspended, and the temperature reduced to the surrounding medium. Cold is evidently a predisposing cause to all these states. Cuvier, however, has remarked that in some warm latitudes, as, for example, in the Isle of France; there are certain animals which fall into a state of torpor only during the hot months.] X [There is a good deal of difference in thi9 respect in different animals. The hedgehog and dormouse awake every three or four days when the weather is mild, and during the interval of activity pass the urine and faeces freely, which could not be the case if they did not digest and secrete during their state of torpor. This has never been observed of the bat, because the bat is an insectivorous animal, and would awake in vain if there were no insects. The circulation, however, is continued even in the bat at the rate of twenty-eight strokes in the minute during the state of torpor. (See Phil. Trans., 1832.)] 78 HUNTER'S PRINCIPLES OF SURGERY. This suspension of several of their actions seems natural to them, being part of the economy of such animals. In other animals, where a suspension of several of their actions takes place from cold, it seems a force on those actions, as it rather seems to lead to the destruction of the animal than the preservation of life. We cannot give a stronger instance of the forcible power of the suspension of actions in animals from cold than what happened to Dr. Solander and others in their voyage round the world. Returning from a hill in Terra del Fuego, they wrere suddenly surprised with a degree of cold beyond what they ever felt before. Dr. Solander advised that they should immediately make their way to the ship as fast as possible, and he himself would bring up the rear. However unnecessary it might appear, Dr. S., who had crossed the mountains in Switzerland, well knew the danger of being left, and told them that they would soon be attacked with an almost irresistible propensity to sleep ; that whoever gave way to the feeling would sleep, and whoever slept would die. But after this very serious caution, the doctor was the first who felt the sensation he described, and could scarcely be persuaded by the united efforts of Mr. Banks and the others to proceed. Mr. Banks's black servant, Richmond, was the next whose desire of sleep was very great, so much so that, notwithstanding the consequences, he begged that he might be left to die. The Doctor only begged to sleep a little, and promised that he would then proceed. Mr. Banks, finding the case grow more serious every moment, sent forward four of the company to the first place where they could light a fire, the rest staying and endeavouring to bring up the few who had lain down. The Doctor was awaked, but their efforts were less successful on poor Richmond. In the midst of their endeavours to rouse him, they felt the same symptoms stealing on themselves very fast; it was in vain to attempt carrying, every one being scarcely able to carry himself. Having proceeded about a quarter of a mile, they met two of their party with the welcome news of a fire being kindled at the distance of half a mile. These two were despatched in search of Richmond. Having warmed themselves, and becoming apprehensive for the fate of the two, a party set off in search of them. They had missed their way, and become victims to the malady from which they had endeavoured to restore the black. Richmond was found just crawling, and brought back, but no means had the least effect on the other two.* * [Many thousands of Napoleon's army are reported to have perished nightly from the same cause during the retreat from Moscow. Sir B. Brodie classes the effects of cold in the following order: "1st, It lessens the irritability and impairs the functions of the whole nervous system. " 2d, It impairs the contractile power of the muscles. » 3d, It causes contraction of the capillaries, and thus lessens the superficial circulation and stops the cutaneous secretion. "4th, It probably destroys the principle of vitality equally in every part, and does not exclusively disturb the functions of any particular organ." (MS. Notes of Lectures by Sir B. Brodie apud Paris.)] OF THE HEAT OF ANIMALS. 79 Winter.—I took two hedgehogs, not full grown, from their huts; the weather for some days preceding had been severe and frosty; the heat of the atmosphere was 44°. In one the thermometer was introduced at the pelvis, and the mercury stood at 45°; and at the diaphragm at 48°. In the other I found the heat in the pelvis 46°, and at the diaphragm 50°. The degree of heat of these animals being so low, it was compared with the heat of a puppy. The heat of the atmosphere during this experiment being 50°, a thermometer was introduced into the belly and pelvis of the puppy ; the mercury stood at 101°, and also at the diaphragm. Summer.—Atmosphere at 78°. A thermometer was introduced into the belly of a freshly-caught hedgehog. In the pelvis the mercury rose to 95°, at the diaphragm to 97°. From the foregoing experiments we find that the temperature is allowed to fall lower than the standard, which is productive of no evil excepting suspending such functions as require the standard degree of heat for their actions. Animal matter endowed with the living principle, whether endowed with action or not, or whether of the first or second order of animals, as far as I am acquainted, admits of the temperature going somewhat lower than would serve for the congelation of the same matter in a dead state. The more imperfect animals vary their heat according to the atmosphere in some degree. I made the following experiments on fowls, which I considered to be one degree above the amphibia, and one degree below what are commonly called quadrupeds. % . I introduced the ball of the thermometer successively into the rectum of several hens, and found the mercury at 103°, 103£ , or 104°. Cocks furnished the same results. In hens during incubation the heat was the same. Living eggs under the same hens raised the thermometer to 99°; an addled egg only to 97 . bo that the living egg had some power of generating heat. In the more perfect animal, as the fowl, the heat is not allowed to come so low as in the more imperfect. _ The power of generating heat keeps the higher animals as near one standard as possible ; but it was not necessary that this standard should be very exact, therefore we find that they are in some degree influenced by external heat and cold, somewhat similar to inanimate matter and the more imperfect animals.* As parts recede from the common mass, as extremities, fingers,

* [In the more perfect animals the temperature of the vital parts is.more easily elevated above the natural standard than depressed below it. Thus, it was found in Capt. Parry's second voyage, that out of sixteen foxes, which were Slea while the Lrmornete, was from 3° to 32° below zero, the *"V$™« eleven varied from 100° to 106}° ; and so in other cases it has been obswjed that the temperature of the blood at the heart bears no relation to the external cold ; a fact which cannot equally be affirmed in regard to neat. J 80 HUNTER'S PRINCIPLES OF SURGERY. toes, the combs of cocks, &c, they are more subject to be affected by cold, and will raise or sink the thermometer in some measure according to the external degree of heat or cold applied ; though not in a proportional degree to this application, as would be the case in inanimate matter. I put the ball of the thermometer under my tongue, and kept it there for some minutes, when it rose to 97°, but would not go higher. I then took several pieces of ice and put them in the same situation, allowing them to melt. This I continued ten minutes, and found on introducing the thermometer that it fell to 77°, and gradually rose again to 97°. I thought the urethra would do still better, and I introduced the ball of a thermometer into a man's urethra. At one inch from the extremity the mercury rose to 92°, at two inches to 93°, at four to 94°; at the bulb of the urethra it rose to 97°. Thus we see that projecting parts are subject to have their heat lowered by surrounding cold. To render this experiment more conclusive, I endeavoured to render this part colder by applying a colder medium to the penis than the common situation. This part was immersed in water at 65° for a minute. The thermometer, introduced an inch and a half, rose to 79°. To find if there was any difference in the quickness of heating and cooling between living and dead parts, as also what difference, I made the following experiments. I procured a dead and a living penis: the heat of the living penis, an inch and a half in, was 92°. I heated the dead one to the same degree, then immersed both in water at 50°. The dead one cooled fastest, but only two or three degrees ; the living one coming down to 58°, while the dead one came down to 55°. I repeated the same experiment several times with the same result. The standard heat of the human body is about 99, and I believe that degree is pretty regular; however, this regularity in some degree arises from there being in every body a considerable mass of matter which causes less consumption of heat. This standard is necessary for the more material actions of life. The heat of the more imperfect animals is not the same in every part of the body, even when there appears an equal mass of matter. To ascertain this, I took a healthy dormouse, the atmosphere being at 64°. I put the thermometer into the belly, nearly in the middle between the thorax and the pelvis; it rose to 74°: at the diaphragm it rose to 80°, against the liver to 81^° As there is some difference between the heat of an animal at the source of the circulation and that of the mouth, pelvis, and rectum, we must make an allowance in judging of the heat of the heart by that of these parts. I next wanted to ascertain if cold applied to an animal would act as a stimulus, and therefore greater heat be produced than the common standard. THE HEAT OF ANIMALS. 81 I took a healthy mouse,—atmosphere 64°,—introduced the ball of the thermometer between the thorax and pelvis. The mercury rose to 74^°, at the liver to 8150. I put the mouse into an atmosphere at 30°, and when the ball was again introduced into the belly the mercury rose to 92°, at the liver 93°, the animal being still very lively. Here was an increase of 17£° in the belly, and llf at the liver, and this produced by the application of cold to the skin. Of the Resistance to foreign Heat above the standard.—We have found that animals evidently possess a power within themselves of producing heat when in a cold atmosphere, so as to keep their bodies in a temperature suitable to the economy of the animal. But as animals are often placed in an atmosphere much hotter than their standard heat, I wanted next to see how far they have a cooling power, or, if they have not, to what degree the heat of an animal might be increased, and wThat might be the consequence of that increase, supposing it possible; for a priori we should suppose that the standard heat, or that heat at which all the animal functions are best carried on, would be the medium heat of the animal. But I find from experiment that the standard is generally within a degree or two of the ultimate heat that the animal can bear. As allowing the heat to rise above the standard could answer no wise purpose, Nature has put a check to it by making the stimulus of heat the cause of its own annihilation, just as the stimulus of cold produces, on the other hand, an increase of heat.* This would appear to take place in two different ways: one is by evaporation, which arises from the action of the living powers; and the other by an immedate power of destroying heat. So that animals have two means of destroying heat, while it would appear that they have only one for the production of it. I put a viper into an atmosphere at 108°, and allowed it to stay in seven minutes, when the heat in the stomach and anus was 92£°, beyond which it could not rise in the above heat. The same experiment was made on frogs with nearly the same success, t I now tried to what degree of heat I could bring a more perfect animal; and as I found the penis the best part for trying the experiment with cold, I imagined it would be the best for the trial of heat. The experiments were made in the same manner with the former, only the water was now hotter than the heat of the man. These were only simple experiments, but I chose to make a comparative one with a dead penis. A living and dead penis were immersed in water gradually made warmer and warmer, from 100° to 118°, and continued in this heat

* [The cause of animal heat is considered in the Treatise on Inflammation, Part II., chap. iii. sect. 3; and the mode by which the temperature is regulated, at sect. 4. The reader is referred to this part of the Work, as well as to the author's paper on this subject in Vol. IV. f [According to De la Roche, the temperature of frogs does not rise above 80^ to 82° in a medium of 110° or 115°. (Journ. de Phys., torn, lxiu.)] 82 HUNTER'S PRINCIPLES OF SURGERY. for some minutes. The dead penis raised the thermometer to 114°, while the living could not raise it higher than 102i°. It was observed by the person on whom the experiment was made, that about a minute after the part was put in water the water did not feel hot, but on the water being agitated it felt so hot that he could hardly bear it. On applying the thermometer to the sides of the living glans, while in the water, the mercury fell from 118° to about 104°, while it did not fall above a degree when put close to the dead penis, so that the living glans produced a cold space of water about it.* This experiment may furnish a useful hint about bathing in water, whether colder or warmer than the heat of the body; for if it is intended to be either colder or hotter, as it will soon be of the same temperature with that of the body, the patient, if in a large bath, should move from place to place, and in a warm bath there should be a constant succession of water of the intended heat.f The experiments made by Dr. G. Fordyce in heated rooms prove, in the clearest manner, that the body has a power of destroying heat. The action of evaporation produces cold, and in proportion to the quickness of the evaporation is the cold produced; and from experiment we find that the evaporation of spirits of wine produces cold faster than that of water, and of asther faster than spirits of wine. On this principle we suppose that evaporation is one means of producing cold in the living body.J It appears from Dr. Fordyce's experiments that the living powers were very much assisted in generating cold by evaporation, but that evaporation was not the sole agent in keeping the body cool. There is therefore a further provision of Nature for enabling animals to support great heat. In order to keep up a just balance of temperature, it is probable that the living powers exert greater effort as evaporation is deficient, and less effort as evaporation increases. In emergencies, evaporation is not sufficient: when a greater power of producing cold than ordinary is required, the powers of the animal are called forth. As animals can only destroy a certain quantity of heat in a given time, so the time they can continue the full exertion of this de- * [These experiments on parts of the body are evidently inconclusive, inasmuch as any elevation of temperature is necessarily prevented by a continual influx of fresh blood, which carries c-.T the heat.] f [Upon the same principle the sirocco and scorching winds of the African deserts are so destructive of animal life. In the expedition to discover the N. W. Passage, the sailors found a temperature at zero attended with a breeze far more difficult to resist than a temperature at 50° below zero attended with a calm atmosphere.] X [The influence of evaporation in producing this effect has been fully investigated by De la Roche, who arrived to the general conclusion that evaporation from the lungs and skin is the main cause by which the temperature is re<mlated in all cases, and the sole cause by which this effect is produced when the body is exposed to a temperature above its own natural standard. (See Journ. de Phys., torn, lxiii. lxxi, and lxxvii. See also Treatise on Inflammation, loc. cit.)] OF THE HEAT OF ANIMALS. 83 stroying power seems also limited. It is probable that both the power of destroying heat, and the time in which that power can be exerted, may be increased by frequent exercise. When Dr. Fordyce was in the heated room, his hand became so hot as to make his body feel cool to it.* It is probable that that part, from its habit of changing its degree of heat, is more ready to take on different degrees of heat applied. It is found from experiment, in the application of cold, that all the extremities are more subject to the laws of inanimate matter than the body; and the nearer the source of circulation, the greater the deviation is from these laws. Possibly the same may be observed with regard to heat. In animals which have a standard heat it would appear to be more natural to form than to destroy heat, (although the power of destroying it appears to be much greater than that of producing it,) for we may observe that they live with much more ease to themselves when in an atmosphere considerably lower than their standard, in which they must constantly be generating heat, than in an atmosphere even of their oWn temperature, in which it cannot be necessary for them to form heat; so that either this action simply of generating heat, or being in such a degree of cold as makes this action necessary, proves salutary to the constitution.-j- Perhaps the medium between their extreme heat, which is 98°, and the lowest degree they can come to, is the proper and most wholesome temperature of the atmosphere, and this is about 63°. Some of these animals which are endowed with this property of a standard heat have this power of generating heat much stronger than others, and are always best in those situations where this power can be exercised: we should naturally suppose that this power always requires a necessity for that exertion equal to its power, so that the power and the necessity should always be proportioned. This cannot be the case with those imperfect animals which have little or no power of forming heat, but are obliged to the atmosphere for heat. When we consider the white bear, the fox, and wolf, in the more northerly climates, inhabiting countries where the temperature is below zero, yet having a power of preserving their noses, feet, tails, &c, while man, with all his care and art, loses his extremities in the same degree of cold, we must acknowledge that those animals have by much the greater power of generating heat of the two. When we compare the above animals with the lion, tiger, monkey, &c, we find the proportion in the power ofgenerating heat between

* [This effect probably arose from the superior denseness of the cuticular covering of the hand preventing perspiration.] X [It is certainly a remarkable proof of Hunter's penetrating sagacity that he should have been able to arrive at so general a truth without being acquainted with the true cause of animal heat, or the intimate connexion which subsists between this function and that of respiration. (See Treatise on Inflammation, loc. cit.)] 84 HUNTER'S PRINCIPLES OF SURGERY. those two classes of animals still greater; for if the human species finds it impossible to generate heat like the white bear, &c, the lion and tiger must find it impossible to generate heat equal to man: for though they may not lose parts of their bodies when in cold that is tolerable to the human species, they lose their lives in the end.* It may be desirable to inquire into the proper temperature for each of those classes above mentioned, that is, the temperature in which they carry on their ultimate actions.t This must be ascertained with great difficulty; perhaps the temperature suitable to the white bear, &c. is about 50° ; for the human species about 60°; for the lion, tiger, &c. about 70°: and there may be some which require a still higher temperature, though probably none will require a lower than 50°. On the Effects of Climate.—By climate we mean that state of the atmosphere which is peculiar to any particular part. Climates vary as much as anything in nature. Their difference may be said to arise chiefly from the influence of the sun, from their moisture or dryness, which will depend partly on the shape of our globe and its oblique direction with regard to the sun, and also from the nature

* [Habit in this instance has great influence, so that the calorific function actually increases or strengthens in winter and diminishes in summer, (Edwards, De l'influence, &c, pp. 162 seq., 242 seq.) an effect which we cannot but observe in those who have resided in the East and West Indies returning to an European climate.] X [By ultimate actions Hunter probably means generation, as he has stated the continuance of the species to be the ultimate end for which the vital powers are given to animals.] X ["Vegetables and animals are prepared for almost all climates, and for temperatures higher than the heat of any country. Dr. Reeve found larvae in a spring at 208° ; Lord Bute, confervas and beetles in the boiling springs of Albano that died when plunged into cold water. A species of chara will flower and produce seed in the hot springs of Iceland, which boil an egg in four minutes. One plant, uredo nivalis, which is a mere microscopic globule, is said to grow and flower under the snow. " Some cold-blooded animals bear heat very badly. Dr. Edwards says that frogs die in a few seconds in water at 107°, [but Dr. Marshall Hall states that a frog plunged into water at 120°, "first struggles violently, then experiences convulsive movements, and then promptly dies, whilst the limbs become exceedingly and permanently rigid. After apparant death, all sensibility and motion having ceased, the heart is found to beat for a considerable time, presenting the singular phenomenon of an animal dead to animal life and maintaining a sort of vegelative existence only." (Hall on Circ, p. 174.)—Editor.'] Yet a species of taenia has been found alive in a boiled carp ; but then the carp which it inhabits will live in water as hot as human blood. " The germs of many insects, &c. are unaffected by a great range of temperature, I know a gentleman who boiled some honeycomb two years old, and after extracting all the sweet matter, threw the remains into a stable, which was soon filled with bees. Body lice have appeared on clothes which had been immersed in boiling water. Spallanzani found long ebullition in the open air favourable to the appearance of the animalcules of vegetable infusions; and the application of great heat in close vessels, although it prevented the appearance of a larger kind of animalcule, did not that of a smaller."—Elliotson's Phys., p. 246 See note p. 284.] OF THE HEAT OF ANIMALS. 85 of the surface, whether hilly, or flat, or woody. The different seasons are dependent on the form of the earth and its motion round the sun. Between the tropics the variations of seasons are less; still there are kinds of seasons, and the climates are very various. The greatest variety of climate is near the tropics. The world there, being chiefly, if not altogether, heated by the sun, works very hard to gain as much of its influence as possible; it exposes itself to it as much as possible in every direction. The air of the equator is very different from that of the poles; few can live in the climate of the poles, either animals or vegetables, and even of those which can live many become torpid during the winter. It is wonderful, considering the necessity of heat to animalization and vegetation, and how partial Nature has been in the distribution of it, how both these processes go on so well as they do.* Nature, however, has been obliged to adapt animals to their different climates as well as vegetables, except the bramble, which lives between the tropics and at the poles. Some animals become torpid during the cold, others even of the same order do not; this seems to be because the food of the first is not to be found during that season: so Nature formed them either animals of passage, as some birds; others she constituted so as to become torpid. Animals of passage, however, seem to have their peculiar climate ; fish, which wander more than most animals, have their climate, and the general cause of their moving south is for the purpose of propagation. So herrings come from the North Pole to the coasts of Europe and America, for no other purpose than to lay their spawn. Quadrupeds seem the best formed for variations of climate, though their heat is more stationary. There are exceptions, as the dormouse, bat, &c.; but men, dogs, deer, horses, &c, live tolerably well, though not without disease, between the tropics and also far north. Nature has furnished some animals with mechanical means for adapting them to climate, as hair, feathers, &c. The use of hair is clearly to preserve warmth : the porcupine of Italy has no hair, but only quills; and the southern bears have only bristles, without hair. There are some animals furnished with proper non-conductors of heat, as seals, sea-cows, &c, whose hair can be of little use to them while living in the sea, and is therefore only useful to them perhaps while on land. Those animals, as whales, which, from living constantly in water, could derive no advantage from hair, have an immense quantity of fat, which is a worse conductor of heat than water by nine to one.t

* [Cold, however, interrupts the growth and nutrition of organized bodies, as may be seen in the short stature and small size of the Greenlanders, Laplanders, Esquimaux, &c, as well as in all the plants and animals of cold and mountainous regions.] f [The white hair, white skins, and white flowers which characterize the productions of the frigid zone are designed for the same purpose, in as much as heat radiates from white bodies more slowly than from those which are coloured. In 8 86 HUNTER'S PRINCIPLES OF SURGERY.

External heat and cold produce diseases peculiar to themselves. Men are the only animals which go to climates not congenial to themselves, and consequently they are alone subject to the consequences of an unfit climate. Too much heat produces diseases of the liver, though, as Dr. Blane observes, this must depend on some other cause than mere heat, as these complaints are not so frequent in the West Indies as in the East.* Diseases of the bowels and tetanus are also often produced by heat; it also tends to produce fevers. The diseases produced by cold are chiefly those of debility, as chilblains, scurvies : also diseases of the lungs, which are more dangerous than those of the liver. Cold also increases some diseases, as the lues venerea: and changes from heat to cold produce some diseases, as scrofula. As heat is able to volatilize almost all bodies, the impurities of the atmosphere must very much depend on it; but, as Dr. Blane remarks, the same heat which volatilizes bodies will very often decompose them. The plague has not been known between the tropics, nor the jail fever, and very warm climates abound much less with diseases of a putrid kind than temperate climates. How does the atmosphere affect the body ? Is it by the lungs or by the skin ? This question it is perhaps impossible to solve. The purest air seems, cceteris paribus, to be the coldest: and the worst, the warmest, especially when moist, where the situation is low, and where animal substances suspended in it are allowed to putrefy. In a very hot air substances may be volatilized so rapidly that decomposition cannot take place; this air will prove destructive by different modes: 1st, By preventing respiration; for if many substances are volatilized, the air containing them will not reach the lungs, except in too small quantities for the support of animal life.t 2dly, By specific poison, producing a variety of diseases, often sedative, as debility and agues, in marshy grounds ; in other places, fluxes and different kinds of poisons. 3dly, The effects of an impure atmosphere are found in jail distempers and hospital diseases ; very few of the former places are ever free from foul air, and most hospitals are more or less affected with it. There are different modes in which these poisons may affect. A stranger in a marshy country is much sooner affected

the same manner, all the finer furs and downs come from the high latitudes, whereas cats, rabbits, and other animals change their fur into hair when they are transplanted to a meridional climate.] * [If, as Tiedemann and Gmelin conjecture, the functions of the liver and lungs are, in one sense, correlative, viz. that they both tend to free the blood of its carbon, then it is not difficult to understand the greater tendency to diseases of the liver in these climates. The blood equally requires purification, and yet this cannot be effected by the lungs without the production of more animal heat than is required; in consequence of which the liver is called upon to fulfill this extra duty, and from over-exertion falls into disease. In the West Indies the seabreezes materially tend to prevent those consequences which take place in the inland continents of the East.] X [It is extremely improbable that a case of this kind ever occurred, considered merely in respect of climate.] OF THE HEAT OF ANIMALS. 87 than a native or an inhabitant. A person'who has not long been used to a jail will earlier, and with more certainty, be affected with jail distemper. An instance of this occurred at Salt Hill in 1760. The effects were at first attributed to the wine ; but they wrere evidently caused by a few paupers, who were examined by some gentlemen, although the paupers did not appear to be affected. In 1775 some prisoners were examined at the Old Bailey who infected the whole Court, and many died ; the judge on the bench, the jury and evidences, &c. Many poisons are of this kind : a person may carry the infection about with him without being affected himself.* The air is capable of carrying most poisons, and communicating their irritations. The venereal poison cannot be thus raised in a state of vapour, or if it can, it loses its effects in the change. Perhaps next to never coming within the influence of such effluvia at all, it is safest to live surrounded by them in large cities, where, either from the habit of being exposed to their action, or from one effluvium destroying another, the effects are prevented from taking place to the extent that might be expected. However, if the atmosphere, being impure, produced an effect only on those coming into it, all the old residents would be equally healthy as the strangers who come to reside for a time only ; yet this is not the case, for they are by no means all robust; -therefore what may be styled its unfitness produces a debility, and the persons are neither so strong nor so healthy as those resident in a healthy atmosphere, though they feel not the sudden effects with which strangers are attacked.f We have a kind of atmosphere which spreads over various countries or climates in particular seasons only, as lately over England. These have had different names at different times; we call it the influenza; it affects at first dogs, then horses. In 1775 the dogs wrere all ill; and afterwards the horses, before men, felt the influence of it. The atmosphere is the menstruum for various substances, some of which are held in a state of solution, and others in a state of mixture only. Water is held in solution in the atmosphere, and when much of this is suspended, it renders it heavier, as the barometer shows ; and when a decomposition of the solution takes place, the water is precipitated as rain or snow, and the air is made lighter, as the barometer also shows. This decomposition may take place, although neither snow nor rain is produced, and this in consequence of a fresh combination taking place before the ultimate

* [The catalogue of infectious diseases is much curtailed in modern times, actually as well as speculatively; at least, the non-contagionists are now the prevailing sect. The infectious miasm probably consists of some compound in which hydrogen is an ingredient. This appears from the facility with which the odour and noxious qualities of putrid exhalations are destroyed by the vapour of chlorine.] f [The late population returns have exhibited in a striking light the serious effects of crowded houses and a crowded population, in doubling, and in some instances in trebling, the rate of mortality, a fact which is still more strongly exemplified in some of the capital cities of Europe. See Count Chabrol's statistical account of the department of the Seine.] 88 HUNTER'S PRINCIPLES OF SURGERY. end is produced. When the above decompositions take place, the birds and beasts seek their shelter; and an effect is produced on wounds, particularly when in a healing state, and in diseases and ailing parts of the human body, so that persons become, as it were, a weather-glass. We have lately been informed by a German that the variations of the magnetic needle have appeared so much to take place with change of weather, that as much might be learned from it respecting the prognostics of the weather as from the barometer itself. Winds may be easily supposed to bring with them the effluvia of disease. Extraordinary effects are produced by the Harmattan wind, a wind which blows off the interior part of Africa to the coast of Guinea. It generally comes three or four times a year, at certain seasons; it is always attended with a fog, which has no taste, nor could anything be discovered in it by means of glasses thinly covered with molasses. The fog is thickest on the beach, and gets tolerably thin about four miles inland. It lasts often for a fortnight, and produces a pain and dryness in the mouth and nostrils, not as if from mere dryness, but from some acridity: if it continues three or four days, the scarf skin falls off, and the tongue applied to that part of the skin denuded of cuticle is sensible of an acrid taste. Though very prejudicial to vegetable life, it is salutary to animals, curing fluxes and other epidemic disorders, and often restoring weakened constitutions. Fevers which had been imprudently reduced by bleeding, got well in spite of the doctor. The small-pox always yields to it, while it prevented the inoculation from taking effect in some African slaves. Such as were inoculated before the Harmattan set in had the small-pox, and all did well; but such as were not then seized with the symptoms, and these were sixty in number, never felt any other affection but a slight fever and nausea during the continuance of the wind; after which it showed itself in twenty of them: the others were reinoculated, and all did well. GENERAL PRINCIPLES OF DISEASE. 89 CHAPTER IX.

GENERAL PRINCIPLES OF DISEASE.

Disease the consequence of unnatural impression;—may arise from faulty primary arrangement.—Diseased actions often established on the same principles as healthy actions;—some diseases end with the cause;—others continued from habit.—Diseases common to all parts, or peculiar to some ;—obscurity of the physiology of disease.—Of susceptibility to impression and consequent action;—difference of susceptibility in different individuals.—Distinction between susceptibility and disposition;—predisposing causes only susceptibilities.—Susceptibilities of constitution and of parts for different actions.— Universal susceptibility producing local diseases.—Susceptibilities almost specific—Temperament.—Of diseased dispositions.—Dispositions unnatural, but not diseased ;—dispositions for restoration ;—of necessity;—and of disease. —Diseased dispositions have an allotted time for action.—Action.—Disease a disposition for wrong action ;—action the effect of disposition ;—symptoms the result of action.—Action, healthy or diseased ;—diseased action of two kinds.— First symptoms of disease.—Diseased actions arising without proper stimulus. —Too great action ;—too little action.—Diseased actions simple.—Of wrong actions.—Habit of diseased actions.—Of sedatives and stimulants.—Irritability.

Now that I have treated of some of the properties of the animal in health, I shall go on to treat of its imperfections, or diseases. To understand these it was necessary, in the first place, to describe its perfect or healthy state. To describe the parts in a healthy state belongs to the anatomist; their actions in this state to the physiologist ; but the diseased state of these actions, and the restoration of parts to health, to the physician and surgeon. It is hardly to be supposed that disease is ever natural to an animal; it can only be the consequence of some unnatural impression which interferes with the natural action of the body, which impression may take place at the very first formation, or original arrangement of the animal, so as to stamp a permanent unnatural action; or it may take place in the first life, namely, in utero; but much more frequently after birth, when it is exposed to a thousand variations, all which are impressions, and are contrary to the natural actions of the animal, or are, as it were, a forcing it to take on actions which are either to remove those impressions or to destroy itself. It is most probable that diseased actions are established on nearly the same principles that the actions of health are. They are at least similar in a great many of their principles; they destroy the dispositions of parts; they produce growth; they produce the power of removing natural parts; they are ruled by habit; they are affected by every external influence. An animal is so constructed as only to continue some diseases so long as the immediate cause lasts, as in scrofula, when it arises from climate; or which is so constructed as to continue other 8* 90 HUNTER'S PRINCIPLES OF SURGERY. diseases from habit, as a gleet, so as to go on with a disease, although the first cause is gone; and this may be only for a time, as in gonorrhoea; or it may be for ever, as in lues, cancer, &c. Diseases are either common to all parts alike, or are peculiar. They are common to all parts alike, as inflammations of all kinds; as, also, tumefaction, scirrhus, dropsies, &c. The peculiar are those in which there is a fault in the peculiar actions of a part, as involuntary action of voluntary muscles, too much or too little secretion from any of the glands, in short, wrong actions of any part in its peculiar mode of action. After the disposition, the action which should destroy the disposition takes place; the action having taken place, the disposition ceases and the natural action of the parts returns. But this is not always the case. The disposition may be affected in one of the following ways: 1st, The action may destroy the disposition, for instance, in gonorrhoea (and perhaps in many other complaints); in this case the action destroys the disposition, or the inflammation destroys the disposition of the virus. 2dly. The disposition is destroyed for a time, and returns at intervals, or after certain spaces, as in all periodical diseases, or others where the disease ceases for a time, and the disposition continues. 3dly. Where the action takes place, yet does not destroy the disposition, as the venereal disease, which goes on till it is cured or kills, and the action of it never destroys the disposition.* Many diseases often require their full action before they produce their effects, as the gout and many agues. Vomiting is the action following the disposition to sickness, and is often its cure, for without it the nausea and disposition will continue. Sometimes chronic diseases will be cured by acute ones, in which case, the full action being given, the disposition is removed. General Observations on Susceptibility and Disposition, constituting Constitutions, and on Actions forming Symptoms.—The physiology of disease is more extensive, more obscure, depends less on general laws of nature (being often a prevention or perversion of those laws), and is therefore more irregular than any part of science, and is of course less understood. The most simple idea I can form of an animal being capable of disease is, that every animal is endued with a power of action and a susceptibility of impression, which impression forms a disposition,! which disposition may produce action, which action becomes

* [It is scarcely necessary to observe that this dogma respecting the venereal disease is no longer entertained ; and indeed it may be questioned whether there is any disease, unattended with actual change of structure, which is not susceptible of a natural cure. This at least seems to be the broad and leading distinction between curable and incurable diseases, although in practice it is often extremely difficult to say what does and what does not constitute change of structure, the simple consequences of inflammation being always excepted.] f Susceptibility has been too often called disposition. A man is said to be well disposed, or parts are said to be well disposed when they are only susceptible. Disposition is a degree further than susceptibility. GENERAL PRINCIPLES OF DISEASE. 91 the immediate sign of the disease; all of which will be according to the nature of the impression and of the part impressed. That every action, whether natural, preternatural, or diseased, arises from this susceptibility of impression, I think we must allow, which susceptibility may exist without even disposition or action, if no impression or stimulus is made; for the disposition is only formed in consequence of some impression, and the action is only the consequence of the disposition being so strong as to incline a part for action rather than for resolution. Therefore action is the ultimate consequence of impression being made on a part endued with a susceptibility of impression and the power of action, which impression gives them the disposition to act. For from what was said above, parts having susceptibility do not necessarily have the disposition; the disposition arises from some impression, which will, in its turn, produce the action, and this action, or disposition to action, must be sufficient to overcome the natural and habitual actions of the part or whole, just as force overcomes the vis inertice of matter. But susceptibilities are in some so strong as almost to approach a propensity to act, which is probably as strong as the disposition, or often probably stronger.* The actions of the body, and the cause of these actions, with their effects, are exactly similar to those of the mind, and as we are sensible of the actions of the mind themselves, abstracted from their causes or effects, we reason about them as much as we can reason about their causes and effects. This is not the case with the actions of the body, for in them we are only acquainted with the causes and effects, not the action itself; therefore our minds are only reasoning about them from analogy. The susceptibility for action of the mind is not known to the mind itself, but by the consequence of such susceptibility. Some minds are much more susceptible of certain actions than others; thus, some men are more susceptible of anger, others of love. But this does not imply that one mind is always in anger, another in love, &c. * [The reader will probably agree with the Editor that the distinction which is here drawn is not tenable. The author, for instance, says, (p. 99) that action is not disease, but the effect of disease ; but what proof is there that the disposition (which according to the author seems identical with the disease), exists at all, except from the action which it produces and the visible effects of that action ? And, particularly, what proof is there that this latent disposition differs from susceptibility 1 A part may be more or less prone to or susceptible of inflammation, but can a part have the disposition to inflammation (in Mr. Hunter's sense), without showing the action of inflammation 1 If it can, then where is the proof of its existence, except from the proneness or readiness of the part to act in that particular manner 1 which is the idea conveyed by the term susceptibility. I offer this criticism with diffidence; at the same time I cannot but regard the whole argument, so far as it is founded on this distinction, as based on a metaphysical subtlety which ought not to be admitted in philosophical discourse. As there can be little doubt that Mr. Hunter formed these opinions from observing that the disposition (so called) to the venereal disease often remained after the visible symptoms had been apparently cured, the reader will naturally turn to this part of his works for further information.] 92 HUNTER'S PRINCIPLES OF SURGERY. With this susceptibility of mind, a stimulus must be applied to produce the disposition to action. A stimulus of one kind will produce anger, of another kind, love. The action of the mind employs other parts to complete the whole, as when the actions of the mind are employing other parts to produce the ultimate effects. But these are not necessary to the action of anger, for anger could exist without the action of employing other parts, and indeed continue longer ; for this tends to destroy the action of anger, because the effect being produced the cause ceases. Every animal has a variety of susceptibilities which admit of a variety of impressions, each impression producing a disposition peculiar to itself. Also every animal has some of those susceptibilities stronger than it has others, out of all which a vast variety of diseases is produced. Each tendency to a peculiar mode of action gives the character of the animal respecting disease. The sting of a bee, for instance, affecting some people much more than others, demonstrates that there is a susceptibility in some for such actions more than in others. In many the susceptibility will be so strong as only to require a stop to be put to the natural actions, when the disposition and the disease too will take possession of the part or of the whole. An instance of this we have in scrofula, for it often happens that common accidents, as strains, bruises, fevers of all kinds, produce the disease even in situations the most calculated to prevent it, as in the West Indies. Even poisonous dispositions are produced in this way, a blow on the breast or testicle shall produce a poisonous mode of action, e. g. cancer. From this account no animaf is formed with' a disposition for the action of disease. The natural actions are for the good of the animal; but they can be perverted, they can be made to destroy the whole. These circumstances are similar to those of the mind ; some minds are more susceptible of some impressions than they are of others, which produces a disposition to act, which action will be according to the impression. The susceptibility of the constitution may be increased, so as almost to be similar to a new formation, but is never originally formed, by art.* Where the susceptibility is weak, it may be increased and kept so much on the brink of forming the disposition, that it shall only require the least increase. or some other immediate cause, to produce the effect or form the disposition, as a man not naturally fearful may be worked upon so

* [If by art Hunter means the influence of external agents, this statement does not appear to be correct. When, for example, hospital gangrene is prevalent in a ward, probably three-fourths of the inmates would be attacked by this disease, after any operation performed on them. The susceptibility of the disease has surely here been generated, yet they would probably have escaped, if the operation had not come to convert this acquired susceptibility into action. The operation under different circumstances would not have been followed by similar consequences ; the body, that is, is not naturally susceptible of this disease, in the same way that it is susceptible of inflammation or small-pox, without previous preparation ; a new state of the constitution must first be induced,__a point which is clearly admitted by the author in his Treatise on Inflammation.] GENERAL PRINCIPLES OF DISEASE. 93 that the least thing may alarm him. Susceptibilities may be so increased as almost to deserve the name of acquired; constitutions long habituated to particular climates will form a scrofulous habit, or an aguish habit, and a certain way of life will produce a rheumatic or gouty habit. On the other hand, persons naturally susceptible may be made by degrees considerably less so, by being gradually accustomed to the immediate cause, beginning within the degree of impression necessary to excite disposition to action. There is no such thing, strictly speaking, as a predisposing cause. What is commonly understood by a predisposing cause is an increased susceptibility to form disposition to action. When I say I am predisposed for such and such actions, it is only that I am very susceptible of such and such impressions, which impressions must form the disposition; or if it is intended to dispose a person for such and such actions, it is only to render him more and more susceptible of such and such impressions. The susceptibility must always precede the disposition. A disposition is a determined thing,—a thing formed,—a kind of resolution. Of Susceptibilities of Parts and Constitutions for different Actions.—Every constitution is more susceptible of some constitutional actions, both natural and diseased, than it is of other actions, whether natural or diseased; and every constitution is more susceptible of some local actions, natural and diseased, than it is of others. Every constitution is compounded of parts whose natural actions are very different from one another. Thus, the natural actions of the liver are very different from those of the lungs. Therefore we also find the diseased actions of one are often different from those of the other; although every part of the body may. be subject to some one or more common diseased actions, as e. g., the liver kand lungs, which may be subject to common inflammation, or they may both have the same specific disease, as scrofula. Every constitution being composed of different parts, whose natural and diseased actions are different from one another, as above mentioned, these actions being according to the nature of each part, and each part in some constitutions being more susceptible of natural actions peculiar to itself than the same part in other constitutions, so also in some constitutions each part is more susceptible of its diseased actions than the same part is in other constitutions. Thus, as the liver in some constitutions is more susceptible of secreting bile, which is its natural action, than it is in others, so also it is more susceptible of its peculiar diseases in some constitutions than it is in others. Constitutions may be said to be more or less susceptible of this or that universal action, among the first of which may be marked the irritable and the indolent. Secondly, some constitutions are more susceptible of some diseases than others are of other diseases. Thirdly, some constitutions are more susceptible of some diseases than others are. And those constitutions not susceptible of this or 94 HUNTER'S PRINCIPLES OF SURGERY. that disease may be at the same time more susceptible of some other diseases than the first-mentioned constitutions are. For example, some constitutions are more susceptible of inflammatory fevers than of any other fevers; others are more susceptible of putrid fevers; while either one or the other of these constitutions might have some other disease, either violently or mildly, as small-pox, measles, &c. Constitutions maybe more susceptible of some one specific disease than the same constitution of other specific diseases, e. g., some constitutions are more susceptible of small-pox than of measles, or vice versd. Some constitutions may be more susceptible of some specific diseases than other constitutions are, e. g., some constitutions are more susceptible of the small-pox than others are, and yet have the disease mildly. All of which characterize the constitution at large. Of universal Susceptibility to produce local Diseases.—Bodies may be said to be both constitutionally and locally susceptible of diseased action. The erysipelatous fever, which is constitutional, being attended by the erysipelatous inflammation, which is local, is a strong instance of this. Constitutions are more or less susceptible, both universally and locally, of the same disease, as the small-pox fever, when violent, has more violent and extensive local effects; when mild, more mild local effects. Constitutions may be said to be more or less universally susceptible of this or that local action, when one part takes on action without any visible immediate cause, or when any injury (whether constitutional, as fever, or local, as accident), makes parts so injured run into a much worse diseased state than the same injury would have done in others; many parts even taking on specific diseases, whenever the immediate cause is produced, as scrofula, venereal gonorrhoea, &c. Constitutional susceptibilities for diseased actions may be divided into three kinds, and there are also others which are mixed.*

* [There is probably not a more abstruse subject in physiology than that of susceptibilities, which most frequently depend on causes with which we are entirely unacquainted. Mr. Hunter has classified susceptibilities according to their effects and remote causes, without attempting to explain the physiological conditions on which they depend. But we ought not, I conceive, to repose here, as if further progress were impracticable, but to ascertain, if possible, the actual conditions of the organization on which they depend, or the particular manner in which the functions reciprocally react on one another so as to produce them. The pathologist should seek to trace the remote cause to its utmost effects, so as to arrive as near as possible to the immediate efficient cause of the susceptibility in question. An example of this kind has been already adduced in regard to the susceptibility of the liver to disease in hot climates, (see note, p. 86,) arising from a reciprocity of function between it and the lungs, of which many similar instances might be given in respect of the other organs. The heart and the brain are said to be more susceptible of disease now than they were formerly, although this GENERAL PRINCIPLES OF DISEASE. 95 1st, An original constitutional; that is, where there is a universal susceptibility for diseased action of one kind or another, in which, however, the whole must be in action, as inflammation, fever, small-pox, &c.; also sympathetic fevers of all kinds. Persons may be very susceptible of the whole of these, or only of one or more. 2d, Original local; that is, where the whole is so constructed as to be universally susceptible of going into diseased action in any one part; but the actions will be always local and independent of every other part, as scrofula, gonorrhoea, or chancre. Hence the venereal disease is worse in one than in another, and yet is local; the same with scrofula. 3d, A susceptibility to fall into universal indisposition, as if there was something teazing the whole ; which then can call on a part, and that relieves the whole, as in gout, rheumatism, and perhaps all those diseases where the local action is critical. Most of these can be relieved by a universal facility to action, or retarded by the contrary, which will affect either the local action or the constitutional one. Strong susceptibilities of a constitution to take on diseased disposition and action, whether of the whole as such, or a local effect of a constitutional disease, (which last I call an act of the constitution), only require the impression of the immediate cause for the disposition and action peculiar to these susceptibilities to take place. These immediate causes may not be the same in two constitutions, although both have a strong susceptibility for the same action ; for what will produce the action in one constitution may not produce it in another. One constitution will require one immediate cause and another another, though both constitutions may have a susceptibility for the disease. Two men equally susceptible may be exposed to the cause of an ague : one may have the disease the other not. It is exactly similar with the mind : two men may be naturally or constitutionally equally susceptible of anger, but each must have his immediate cause ; what will bring forth action in one will have but little effect on the other, and e contrario. It is the same thing with every effect of the mind. Most susceptibilities are so much of a specific nature in themselves that each susceptibility shall be brought into action, in nineteen people out of twenty, in one way, and probably in the twentieth it has been prevented by what produced it in the others. This accounts for the same diseased action in people arising from so many different causes, and also accounts why such disease, though having a specific mode of action, may be varied in the same person

may solely depend on the complicated interests and passions of modern life, which necessarily induce particular physical conditions of these organs which directly tend, on known principles, to the production of disease. The constitutional susceptibilities are, in general, far more obscure, and scarcely at all admit of this mode of explanation.] 96 HUNTER'S PRINCIPLES OF SURGERY.

in different ways, still more in different people, and even often require different modes of cure. This theory may be illustrated by every disease that takes on full specific action; whether a full constitutional action, as an ague, or a local one, as the gout. As an ague is a well-known and well-marked disease, this theory will of course be illustrated by this disease. Every constitution has more or less susceptibility to fall into an aguish habit; but there must be in all an immediate cause to produce the disease. The immediate cause may be such as will make nineteen people out of twenty fall into aguish action ; but many constitutions, though they have a susceptibility of falling into an aguish habit, yet when the immediate cause takes place, may have no disposition to take on the full action of that disease ; by which means the constitution is teazed by what is called a badly-formed ague. If the immediate cause be some local disease in the body, as diseased liver, spleen, &c, then the cure must be effected by the cure of the liver, &c. This reasoning may be taken in another point of view. Suppose twenty people having different susceptibilities;—introduce something that shall endanger the constitutions of the whole number, and each shall take on the disease that he was at that time most susceptible of, whether ague, gout, or any other. But often that which would become the immediate cause in those already susceptible of action, or already predisposed to it, by repetition or continuance becomes the predisposing cause in others not susceptible. If two men, one so susceptible as only to want the immediate derangement, the other not at all susceptible of an ague, be sent into the fens of Lincolnshire, the first shall have an ague immediately, because he only required the immediate cause of it; the other, if he does not get the better of the climate by habit, shall become aguish in time, because the country will become both a predisposing and an immediate or exciting cause. We may substitute for the disease of ague some other disease, and the whole of the above reasoning will be perfectly applicable. But where it is the nature of the disease to take on local action, as in gout, there must not only be a universal disposition for such disease, which is the original, but there must also be a local preference, or rather a local susceptibility superior to the rest; and when the immediate cause takes place, so as to form the disposition, that part takes on the whole action, which relieves the constitution of such disposition, except it should produce another constitutional effect by a vital part taking it up, by which means it would effect the whole constitution similarly to any of the affections of this vital part, where a diseased disposition is formed, but does not take on the regular type of the disease, or does not take on the full and complete action; as in the aguish disposition not having gone through the regular stages of the ague, or gout not having formed a regular fit. GENERAL PRINCIPLES OF DISEASE. 97 In those diseases that become local, as gout, some attention is to be paid to the seat of action; for if a vital part takes it up, it must be much worse than when there is only a constitutional affection. The qualities of periodicity and regularity in constitutional diseases, or the power of a constitutional affection to become local, are, I believe, but little understood. Susceptibilities for dispositions and actions appear to me to be the same with what are usually understood by temperament. Temperament is the state of the body fitting it for the disposition or action it is then in, whether it is only a state of susceptibility, of disposition, or action. The action is always the best test of that state : but, although the action is the best test, yet there are some circumstances attending animals that either dispose them for, or are concomitant upon, such and such susceptibilities; and from these circumstances we can say beforehand, although only in a general way, what are the most predominant susceptibilities for certain actions in this or that animal. We see that even colour in animals depends on a difference in their temperaments, or is concomitant with temperament; for animals with fair skin and hair are more susceptible of cold than the dark, as also of pain. This is well known in the army, where we find that the power of bearing violence committed on the body is in proportion to the darkness of the individual. Fair people are more irritable in their minds, more susceptible of anger, and probably of all other passions. Fair people are also more susceptible of certain diseases than the dark, as of scrofula. This may arise from their not being able to bear the vicissitudes of climate; for it is in changeable climates, especially where there is cold, moisture, &c, that scrofula is more predominant. The irritable inflammation also is more common in the fair than the swarthy. As the fair are less able to resist cold than the dark,* it might be supposed that the dark are less able to resist heat, therefore more ready than the fair to run into diseases which warmth has a tendency to bring on. But from the estimate made by Dr. Young in the Island of St. Vincent's, it would appear that there is some reason to suppose the contrary; from which it would appear that the dark-coloured are rather fitter for all kinds of climates. Of diseased Disposition.—Dispositions are natural or unnatural, including diseased. The natural belong to the healthy animal, therefore are not to our present purpose. Dispositions maybe unnatural (and of course the actions arising from them unnatural), and yet not diseased.

* [This must be understood with some limitation. The inhabitants of high northern latitudes, who are often very fair, are far less susceptible of scrofula than the darker-complexioned races of more southern countries; as, on the other hand, the African and the half-caste are more liable to this disease when transplanted to a northern latitude than the natives. It is not merely cold, but cold and moisture, associated with a variable climate, which predispose so 6trongly to this disease.] 9 98 HUNTER'S PRINCIPLES OF SURGERY. Unnatural dispositions and actions we shall divide into three kinds, or they may arise from three causes, which are remote. 1st. The disposition of restoration, in consequence of some injury done, which is also a consequence of every disease which is curable. 2d. The disposition arising from necessity, as the thickening of parts from pressure, ulceration of every kind. This includes a great variety. 3d. Diseased dispositions of all kinds, which also includes a vast variety. From this division we see that there are two preternatural dispositions that are not diseased, so much so that the first may be reckoned a disposition of health; therefore there is but one preternatural disposition to action, which can be called diseased, namely, the disposition to destruction, and which is to be cured by substituting the first disposition. Diseased dispositions may arise from some fault in the animal powers themselves, or some extraneous matter in the constitution or circulation, as in the case of many poisons, or from many substances acting on the stomach called poisons, or from some substances being applied externally to the body which disagree with animal life in general, as too much cold, too much heat, &c. Every diseased disposition most probably has its allotted time for action after the impression, or after the formation of the disposition. This is remarkably the case in specific diseases; but yet this will differ according to the susceptibility. The same with poisons: the small-pox is about six, seven, or eight days at a medium; the measles the same. The venereal disease has a medium, although it varies. But some specific diseases shall remain a considerable time before the action takes place; and this will be much longer in some than in others, according to the nature of the diseased disposition and parts. In cancer it is often very tedious. I have seen instances where it was years after all continuance of the cause was removed before the glands in the armpit had taken on diseased action after contamination. A girl at St. George's Hospital, fourteen years of age, born in the West Indies, left that part of the world when ten years of age. About a twelvemonth ago she had an eruption on the skin in several parts of the body, especially on the face, arms, and hands. The eruption arose like warts, or like large moles, about the size of half a crown piece, above the surface of the skin, irregular in their base. some standing single, others running into one another, of a browner colour than the common skin, which was clear and of a firmer texture. Now this was a West Indian disease; therefore I say that the girl was contaminated in the West Indies. The impression was made there which was the first cause, and the disposition was formed; but the disposition did not come into action for three years after. The removal to a cold climate, though it could not remove the disposition or prevent its effects, yet protracted them. It may be further remarked, in specific diseases and in poisons, GENERAL PRINCIPLES OF DISEASE. 99 that if the specific disease or poison is such as is capable of contaminating different parts, whose powers or readiness to act is different, the same disease will show itself at different intervals in these places in the same person, though perhaps every part is contaminated at the same time. Thus we have the venereal disease appearing in different parts at different intervals in the same person, arising from the natural susceptibility for action in some parts being greater than in others. The skin and tonsils being most susceptible of contamination, as also of action, are therefore affected soonest; the bones and tendons less so, and are therefore later in taking on the action. The disposition simply does not seem to affect either the constitution or the part, (see note, p. 91) for either shall go on well with all their natural functions, and powers of restoration when injured or affected with diseases of every other kind, although at the same time in the disposition of some other disease. Dispositions of one kind may be restored after being destroyed for a time by a more powerful impression, or such as the constitution is more susceptible of, which shall supersede the first disposition, and go on with its actions; and when its action is completed, the first disposition shall again take place, as will be illustrated when we come to talk of actions simply. Action.—I have explained that a disease is a disposition for a wrong action, and that the action is the immediate effect of the disposition, and that either the actions, or the effects of those actions, produce the symptoms which are generally called the disease, such as sensations, which are commonly pain of all kinds, sickness, alteration visible or invisible in the structure of the part or parts that act, and sympathy. The animal, or part disposed to act, generally takes on action, which is of three kinds: natural, restorative when injured, and the diseased; each arising from the corresponding class of dispositions, and therefore divisible into the same. The actions of health arise from a disposition to act properly, that is, according to the combined laws of the machine, which may be either universal or only partial; for a man may be wholly in health, or only so in part. The actions of restoration are for the falling back into the above natural actions, and which will be according to the nature of the injury done and the parts combined. The diseased actions are many, but may be ranked under the following heads: 1st. Improper actions of natural parts, as spasms of muscles; irregularity in the times of action of a compound part. The nerves have the credit for being the remote causfc of all these. 2d. Unnatural or improper actions of the vessels; and these may be either attended with an increased or diminished action. The ultimate and visible effect of disease is action; but this is not the disease, for the action is only an effect, a sign, or symptom of disease. But the disposition being only discovered by its effects, we are apt to go no further in our inquiry, the cause being to many 100 HUNTER'S PRINCIPLES OF SURGERY. only an object of curiosity. However, the effect must be attended to, for it is this which leads us to the cause. These actions may arise from poisons,or substances improperly applied to the surface; from cold; from substances taken into the stomach: these usually give a sensation to the animal, so that it can judge that the parts are diseased. But sometimes the action is too slow to give an alarm to the part; or the disease is felt through the irritation; or by a part remote from the diseased part sympathizing, as worms in the intestines, producing convulsions, an itching at the nose, &c. When the hip or loins are affected, the sympathizing part, before the disease is felt in the original seat, is the knee. Passing a bougie has caused sickness before it was felt in the urethra, as has a clyster before the rectum was sensible of any inconvenience. Often the internal feeling of health is the forerunner of disease. People just before a disease shall be in better spirits, and feel strong, so as to take notice of it themselves. A gentleman had better health before a spitting of blood came on. A boy had more spirits than usual the night before he was attacked with the cold fit of fever. Perhaps the cause of disease gives the first feeling of health or vigor: the animal powers are called up on the first alarm of disease; and when they sink, which is the second stage, they produce cold, or shivering, which is generally supposed to be the first symptom. In children I have often observed that the smell is affected before diseases. The first impression here is made on the olfactory nerves. Some diseases come on extremely rapidly, producing at first very violent symptoms, called acute: others come on very slowly, and do not produce any sensible first symptom. I have already observed, that all the actions in a healthy state are only produced by their proper stimulus; but sometimes we have actions without proper stimulus, which are diseased actions. In all organs I have observed there is a regular succession of action, as in the secretion of different substances, according to the wants of the parts which become the stimuli; but they may perform this office without the stimulus. The vessels are very active parts, and have often wrong actions, producing diseases in a great variety of parts, and are peculiarly active in the operations of disease. Too great action will produce disease, according to circumstances. As the powers are equal, or greater, the action is universal or local: if universal, as in inflammatory fever, it will either produce resolution or death; if local, as in inflammation, either resolution or suppuration; or if the action is greater than the power, irritability; or it may keep up a constant inflammation; or if very violent, produce mortification. Too great action will often in the end produce too little action ; but not often vice versd. General action or fever may produce local, as inflammation; or local inflammation will produce general, as fever. They often attend one another from accident, and then they generally increase one another. Too little action arises from a disposition to act within the neces- GENERAL PRINCIPLES OF DISEASE. 101 sary bounds of health, which produces real weakness and a bad state of health, with debility, without any visible state of disease, as we often see in fine ladies. If the part debilitated be not necessary to life, it only produces its effects on that organ. Too little action may subject the person to many more diseases than what the active are subject to. Even the habit of indolence in the mind, joined with inactivity of the voluntary actions (which is generally produced from an indolent state of the mind), produces the same effects, especially as we see in women. So that weakness is attendant on many diseases, and although somewhat necessary to many, yet it is not actually the disease itself. For instance, weakness attends the scurvv, and is necessary before the full effects of the specific disposition, namely, the action, can take place. The same in locked jaw, scrofula, &c. Weakness becomes one of the causes of irritability, as will be explained. Weakness, too, produces an increase of the disease. It may be local or universal, for many parts of an animal body may be weak, while others are strong; and if the weak parts are "not essential to life, then the effect is only debility in performing the function, and the vital parts may not suffer. If the nerves are weak, the voluntary parts suffer; if the stomach, then the whole will suffer, or there may be a weakness which includes the whole without destroying it. It sometimes seems that the suspension of action for a time, increases the power afterwards; and lessening the power of action, increases the real strength at other times. All diseased Actions are simple.—A disposition of one kind may and shall exist in a part or whole, while an action of another kind is going on; and when the action ceases, the disposition, or dormant action, if we may be allowed to call it so, shall then come into action. There are certain natural actions arising in an animal body in consequence of every irritation, whether appearing as a spontaneous injury or from accident. These common actions I shall illustrate by inflammation. Inflammation, then, is one of these simple actions; but we find inflammation may be joined with a specific quality which shall not alter its apparent mode of action, yet shall cause its ultimate effect to vary ; thus, though the mode of action is altered, the action itself is not altered. It appears to me that every disposition must be simple, and therefore be only capable of producing simple action. Parts so disposed may be irritated by something that alters the disposition. If the old disposition be destroyed, a new one must be produced: but if the disposition be only altered in part, there may be the two dispositions in the same part, the old in part and the new in part. But it is possible that a new disposition may be formed out of the two, different from either of the two which formed it; still it must be considered as a simple disposition. This is plain in the cure of the venereal disease ; a third disposition (namely, the healthy,) arises out of the two, that of the disease 9* 102 HUNTER'S PRINCIPLES OF SURGERY. and that of the remedy. This is likewise shown in the action of Dover's Powder, for neither vomiting or sleep is produced, but a third action, namely sweating. But a constitution or part may have equally a susceptibility to a variety of diseases, as venereal, scrofula, &c, some of which may have a common cause, others a specific, as lues : yet the constitution can have at the same time only one specific action. As there are susceptibilities for dispositions, so there must be also dispositions for actions; yet two of these cannot exist at the same time in the same part or constitution. Two children were inoculated for the small-pox. Their arms inflamed ; but about the third or fourth day from the inoculation symptoms of fever arose, and the measles appeared, and went through their progress as usual. During this time the inflammation in the arm was arrested; but when the measles were completely gone, the small-pox took place, and went through its progress. Here a disposition for the measles had taken hold of the body, but although it had done that previously to the small-pox, yet it was not in such a w^ay, as stopped the progress of the small-pox. The small-pox matter was capable of contaminating, and produced inflammation, which went to a certain length, but the moment the measles changed their disposition into action, as the two actions could not go on together, the action of the small-pox was suspended till the measles had gone through its action, and the moment the constitution got free of this, the small-pox began to act again. A lady of rank was inoculated by Mr. Sutton. A few days after a fever came on, of the languid or putrid kind, but without any eruption, except a few petechiae on the breast: she went through the process of a low fever, and afterwards the small-pox commenced ; yet when the pustules maturated they spread wide and were very large : also a different set of eruptions succeeded, so that thirty days passed before the skin was clear of the eruptions. These cases show that but one mode of action can take place at the same time; yet I could conceive that two actions might produce a third one, which might have been a new poison, as the last case in some measure seems to show. Of wrong Actions.—I have already mentioned, under the animal economy, the two different kinds of action in an animal: 1st, The natural powrers of growth, modelling, &c.; 2d, The powers peculiar to each part, voluntary or involuntary. Now, the first may act improperly: it may push forth unnatural and unnecessary growth in some parts, and too little in other parts. They may also act in such manner as to obstruct the necessary actions of the machine, as by unnecessary masses called tumours, increase of the bones, &c. The seeond may also act wrong, that is, may act. without the necessity for action, as in spasms, locked jaw, over-secretions, palpitation of the heart, &c. This is in every respect similar to the former, only the improper action is on a different part. If, then, GENERAL PRINCIPLES OF DISEASE. 103 improper actions fall on a part of importance to the machine, they produce disease: or they may act too little, and thus produce diseases of a different kind. Diseased actions, like the actions of health, become accustomed to impressions, and we see many of them subject to the same laws. This is of two kinds: first, where the diseased part becomes less and less affected by stimulus, from a continuance of the application ; second, where the whole body, or a part, becomes more easily effected by the stimulus, from a repetition of the application. People constantly exposed to the cause of certain diseases become less affected, or less liable to be affected. Perhaps the best way to prevent being affected by some infectious diseases would be to live constantly where the infection was. People coming out of the country into the town are more liable to be affected by certain infections, as the small-pox, than those who live constantly in large towns. The constitution having once felt the stimulus of the smallpox, is not afterwards affected by it; yet I can readily conceive that if a man were to live two hundred years he might arrive at that period when he would again be susceptible of the impression. Of Sedatives and Stimulants.—Perhaps there is no idea of any principle, simply as an idea, more correct than that conveyed by the word sedative, stimulus, irritation ; yet I think it is probable that there is no idea so little understood in practice; and it may be a very difficult task, and next to an impossibility, to say what real state the body or part is in, or can be brought into, to be affected in either one or the other w7ay. This arises from our imperfect knowledge of the true state of the body or parts, or of their economy ; for what might act as a sedative at one time, might be a stimulant at another, or even an irritant; or what might be a sedative to one part, might be either a stimulant or irritant to another, which we shall see to be really the case, for whatever will excite action, even the common action of parts, will be a stimulus, and whatever will excite actions beyond the real strength of the body will be an irritant; and this cause of excitement beyond the common action may be no more than what at another time would act as a sedative. For example, without heat, probably no action could take place either in common vegetable or animal matter. Heat admits of becoming an exciter to action; but as heat, in so far as it can, only excites natural actions, and, in due proportion to the strength of the parts, it may be called sedative; for we may suppose that by sedative is not meant an unnatural reduction of action (for which, indeed, we have no expression), but the production of a natural action from too great an action. It may increase or diminish action, according to circumstances. But to ascertain the precise degree of heat suitable to every state of body or part, so as neither to increase nor diminish action, is probably impossible. When animals are extremely weak, their actions should be suitable to their strength. Or if an animal is only moderately weak 104 HUNTER'S PRINCIPLES OF SURGERY.

in the whole, considered as a whole, yet there will be parts that will be very weak; and if those parts are under disease, care should be taken that those parts are not thrown into action above their strength. The temperature of the body, or parts respecting heat and cold, should be in proportion to this weakness, which will regulate the action, and to apply warmth at such time would be applying a stimulus ; and if the body was still more reduced, warmth might become an irritant; or if the body was not able to act up to this stimulus, it would be an irritant. To lower actions suitably to the state of the constitution, whatever this may be, is the use"of a sedative; but in some constitutions it may be requisite to bring it even lower. So it is often necessary to produce fainting ; but this cannot be called a sedative ; it is probably only weakening. Irritability.—There is no word perhaps more improperly applied than irritability ; it is often used for stimulus, and stimulus often used in place of it. Indeed we must allow that there is a resemblance between them in several of their properties, both exciting actions of the living parts; but they differ very much in the consequent action, as, indeed, irritability appears to be nearly allied to susceptibility. I have already explained, when on the animal economy (p. 62), that stimulus excites or increases natural actions; but an irritation either excites an unnatural quantity of a natural action, or an entire new one ; and susceptibility is the readiness with which they can be excited. Some constitutions are so easily excited, or in other words, so susceptible of diseased impression, as to take up actions so readily as to make them appear natural, which in others are only brought on by disease. That a natural action may be increased beyond its natural bounds we see every day. Salivation is an instance of this. That irritation produces new action is perhaps more evident than the former. Accidents of all kinds are of this kind. Blisters act on this principle. In short, every new action which takes place may be said to arise from an irritation produced in the part, or something similar. Irritations are often producing salutary effects, and therefore may be said to terminate in a stimulus, which is owing to a kind of irritation, such as those which are in consequence of many accidents, which new action produces a restoration of the part injured, as in wounds, compound fractures, &c. There are new modes of action taking place every day that would appear to arise spontaneously (therefore from no possible irritating cause, which, on the contrary, most probably arises from this new mode of action). The immediate cause may be so slight as hardly to approach to an irritation. Such constitutions are called irritable, which is only saying that one part may be irritated by what would have no effect on another. Those unnatural spontaneous actions often arise from a want of power to act properly, with a strong OF SYMPATHY. 105 disposition to action, which is the reason why weakness, or want of power, becomes the cause of irritation, which produces new action, which new action will be according to this want of power and the nature of the part combined. Necessity often becomes the cause of irritation, as when a small opening is made into a large cavity, and not allowed to heal by the first intention, the whole becomes under the necessity of taking on a new action to restore the whole; therefore irritation often produces salutary effects. Many of the preternatural actions are so slow in their motions that we can hardly make them accord with our ideas, which ascribe them to irritation, especially in those that seem to arise spontaneously, as the formation of many wens, encysted tumours, &c. Irritation may be divided into common, specific, and poisonous: 1st, Common, is that which will affect all animals ; 2d, That which will affect only the same species ; 3d, Is also very much confined to species; one only, as far as I know, being excepted,—the bite of a mad dog. So that the disease of one animal, although communicable to another of the same species, is not so to one of another species. Small-pox, chicken-pox, venereal disease, measles, hooping-cough, jail-distemper, itch, scrofula, are peculiar to the human. The disease of black cattle is confined to them ; the rot to sheep ; glanders to horses ; mange to dogs.* CHAPTER X.

Disposition to action arising from sympathy;—without direct impression.— Sympathy of two kinds;—connexion of principles of action in the living body; —sympathies of sensation doubtful.—Sympathy between different bodies.— Sympathy natural or diseased ;—not always reciprocal between parts;—generally single;—common or uncommon;—similar or dissimilar;—partial or universal.—Varieties of partial sympathy;—varieties of universal sympathy; —fever, inflammatory, hectic.—Certain parts sympathise more strongly than others.—Of similar and dissimilar sympathies ;—of simple sympathies ; difference of sympathies from modes of impression.—Sympathy of body with affections of the mind ;—of the mind with the living principle;—use of sympathies—Of delusion ;—explanation of it;—delusion in dreams.

I have endeavoured to show that there are two principles in the higher animals, namely, life and the action of the nerves, which last is called sensation and volition; or rather, perhaps, there is but one principle, life, which becomes the basis of the other and of

* [There are some of the above diseases which aTe now known to be communicable to other animals.] 106 HUNTER'S PRINCIPLES OF SURGERY. every action of the body. I also endeavoured to point out that sensation arose from feelings in the mind, which produce action in the body. I attempted to show that the more simple actions arose independently of sensation or of the actions of the nerves; that the nerves, from their specific actions, only become the cause of many actions, but are not the principle of those actions; that from their termination in the brain they produce sensations there from which is formed mind, and that they also give rise to the will, and form the basis of reasoning. I showed that the mind becomes the cause of many involuntary actions in the body, as reason becomes the cause of the voluntary; and that thus the actions of life, of the nerves, of the mind, and of the will arise from impressions being made on each so as to affect their principles. In speaking of the general principles of disease, I divided the living power into susceptibility of impression, impression, dispositions arising in consequence of such, and action consequent on disposition; all which I observed were immediate or primary. But there is a secondary susceptibility, disposition, and action arising from, or in consequence of, all, by necessity, called sympathy; actions, as it were, playing amongst themselves, each becoming a stimulant to the other, or each being affected by the other. By this principle of action, called sympathy, an action arises without an immediate impression in a secondary way, either acting in conjunction with the part immediately impressed, or taking the whole action on itself. This action without immediate impression is one of the most complicated principles in the animal body, especially the more complicated animals, because it is the compounding of actions. Sympathy may be divided into two species: 1st. A local with a local disease; 2d. A universal with a local. The first may be called local sympathy; the second universal. But all sympathies must arise from a local cause. Sympathy is not confined to the same actions of the same person, but is' transferable from one person to another.* In the investigation of this subject, we shall find all the principles of action in an animal, even in the most complicated, have a connexion with one another ; for instance, the living principle, the action of the nerves, and the mind: and that the same principle in one part shall be affected by the same principle in another ; and this

* [For some curious examples of this sort, see Dugald Stewart's " Elements of the Philosophy of the Human Mind," p. 153, et seq., and Edin. Med. and Surg. Journ., vol. iii. p. 434, et seq., respecting the mode in which some convulsive diseases were propagated in Scotland. A strong collateral argument may be derived from this species of sympathy in favour of that opinion which makes the intervention of the sensorium commune a necessary condition to the existence of sympathy. See Whytt's WTorks, p. 140, and Dr. Alison in Edin. Med.-Chir. Trans., vol. i. p. 165. That the nerves, however, are capable of a reflex action through the medium of the spinal marrow as well as through the brain, is rendered certain by the experiments of Dr. Marshall Hall and by many morbid phenomena. See Med. Gaz., vol. ii., 1832-3, p. 769.] OF SYMPATHY. 107 is the simplest kind of sympathy I can conceive. Thus, the living principle of one part sympathises with the actions of life in another part, as must be the case in all animals which have no nerves.* The nerves of one part sympathise with the actions of the nerves in another, which may produce sensation. The mind sympathises with the mind, which of course can only take place in animals that have mind, and perhaps not in all of them; and it is more than probable that such minds as are capably of sympathy are capable of other complications of affections. Probably what might be called the disposition to action of one principle in one part may produce action of another principle in another part. Thus sensation in another part may be produced, while simple life only is affected in the part immediately impressed. This would appear to be owing to the nature of the sympathizing part. Thus, if an injection is thrown into the urethra in a man, it shall not give pain in the urethra, not even the common sensation of the part, yet the stomach shall be affected and sickness produced, which last is a sensation. I have known a stimulus in the rectum, which did not produce pain in the part, produce sickness and pain in the small intestines, and even stop digestion. Such pain certainly arises from action in the part. On the contrary, simple pain in the finger shall produce a greater action of the living principle in another part, as making the heart beat oftener. The principle of sympathy itself I shall call a genus, of which the above make three species, namely, sympathy of the actions of life, of the nerves, and of the mind. Each of these have their varieties in action, each being susceptible of varieties of impressions, affections, and actions, and all being capable of sympathizing with one another. It may admit of dispute, and probably will be difficult to settle, whether there is sympathy between sensation and sensation simply ; for sensation must arise from some impression made on a part, or some action of nerves similar to those arising from impression. Therefore every sympathy which only produces sensation must still arise from impression on, or action of, the nerves; and the same with the sensation in the sympathizing part. Sensation is only the natural consequence of such action, for sensation is only the intelli-

* [What the real conditions of the organization are on which sympathies depend are unknown, although there seems every reason to ascribe this agency solely to the nervous system. To ascribe it to the living principle is merely eluding the question by a sort of abstraction. The difficulty still returns—what is the intermedium through which distinct and dissimilar parts are thus associated 1 Some intermedium there must be; and as to the difficulty respecting those beings which have no nerves (p. 54, note), the same is equally felt in regard to the higher animals, in which the most powerful sympathies exist, although no anatomical connexion is to be traced between the parts, nor any relation of function or structure observable. Indeed, those structures, such as fascia?, membranes, &c, which apparently have no nerves, are those very parts which give rise to the strongest and most marked sympathies.] 108 HUNTER'S PRINCIPLES OF SURGERY. gence of action, either from impression or arising from the spontaneous action of the nerve itself. I suspect that all those which would appear to be sympathies of sensation only, without action, are a delusion of the mind, a wrong reference of the mind to some other than the part affected, which I shall explain when upon the subject of delusion. From what has been said above, it must appear that sympathy is a principle in animal bodies so intimately connected with every possible impression, affection, and action, that we cannot have a proper conception of the animal economy respecting diseases without taking this principle into consideration. It is one of the secondary principles when applied to the body itself, being the effect of some impression, affection, or action in some other part of the same body. Sympathy arises from every part of the body being ready to fall into affections and actions in consequence of an impression, affection, or action having taken place in some other part. Sympathy is one part taking part in the impressions, affections, and actions of another part. Sympathy is not confined to actions of the same persons amongst themselves, but is transferable from one person to another, in whom it cannot be called a secondary action, as it arises from an impression being made on some of the senses. Yawning is a species of sympathy; and all actions peculiar to country, places, family, &c, ai'e so many sympathies. Dancing may be included among the sympathies, for it is not simply an imitative action arising from the will, but it is an irresistible impulse arising from a state of mind produced by musical sounds. If there were no sounds, or, in other words, not a sense of hearing, there would be no dancing: for seeing would not produce it, probably rather retard it. There is, first, sensation ; then a state of mind formed in consequence of that sensation; and then the action of the limbs excited by that sensation. The idea of sympathy may be stated differently: instead of saying a part sympathizes with another, we may say one part under stimulus or irritation is capable of stimulating another part of the same body into sensation, action, &c, which I think is the most natural idea or position. Sympathy may be divided into two kinds, the natural and the diseased. The diseased is when sound parts sympathize with the diseased, and probably the diseased with the diseased, which is what I mean to explain. The sympathy of one diseased part with the diseases of another part will include the idea of revulsion, as revulsion consists in the production of a disease in one part to cure a disease in another part; which shows that this one part, while under disease, can be affected by a diseased action being produced in another part, or the cessation of one action in consequence of another having taken place in another part. Natural sympathy takes place more readily, and its actions are OF SYMPATHY. 109 more strongly marked, in proportion as the powers of the machine are capable of repairing an injury received. On the other hand, it takes place more slowly, and is less evident, as the powers of life are more languid. In many diseased states the condition of the whole body is often such that it more readily falls into sympathy at one time than at others* Thus we find people at particular periods much affected by slight causes, while at other times considerable mischief received will hardly affect them* Some people are naturally more readily affected than others, as will be evident in disease. Sympathy sometimes proves fatal, as in children from teething. But this depends in great measure on the parts sympathizing, or the number of parts that sympathize. Sympathies are often not reciprocal: the liver never sympathizes with the shoulder, nor the urethra with the testis; nor when the glans penis is affected does any irritation pass to the bladder; but often they are, as, for example, between the head and the stomach. Sympathies are generally simple; we hardly ever find two parts sympathizing with the same cause : however, the spasmodic convulsion of both hands and feet, &c, as sometimes takes place, may be called a double sympathy. Sympathy is common and uncommon. The first is where it takes place more readily between some parts than it does between others, as between the stomach and head, the stomach and the skin, the testes and the urethra. Sympathy may be called uncommon when parts sympathize with diseased parts that were never knowrn to sympathize in health. A gentleman had a sore on the inside of his thigh, which itched so intolerably that he could not avoid scratching it, and when he did, it always produced tightness in his chest and shortness of breathing, which he never had but at these times. Lord Cavendish's father always felt pain in the left arm from a stone in the bladder. This pain was the only indication of a want to make water. Sympathies are either similar to the cause or dissimilar. The similar can be but of two kinds: where the modes of affection or action of the' sympathizer are either wholly similar to the modes of affection or action of the parts diseased, or the sympathizer has one of its modes of affection or action similar, and which is the one that sympathizes. Dissimilar sympathy may be of so many kinds that it is probably hardly possible to be completely master of the whole of the particular varieties. Sympathy may be said to be either partial or universal. Sympathy is partial, from local diseases, when the causes of action in one part become the cause of action in a distant part, as when anything tickles the nose the muscles of respiration act; or it may be partial from a universal disease. But local sympathy with the 10 110 HUNTER'S PRINCIPLES OF SURGERY. constitution has its order of parts, as the stomach sympathizes with the whole body in an incipient fever. Sympathy is either natural or diseased. Natural sympathy always tends to produce some salutary purpose, as the breasts of women increasing with the size of the uterus during gestation. As no part of the body is entirely independent of the rest, in all particular injuries the whole must sympathize more or less ; but as every individual part has a more intimate connexion with some particular part than writh others, these parts sympathize more readily. Local or partial sympathies we call continuous, contiguous, or remote. Continuous is only an extension of the same action, as in most inflammations spreading from the centre ; otherwise, in an injury, the part which received the first impression would alone become inflamed. Contiguous is where one part sympathizes with another where the parts are only in contact with each other, without any continuity of parts, as the contents of the abdomen with the abdominal muscles.* Remote is where one part sympathizes with another part, though at some distance from it. Universal sympathy is when the whole becomes affected in consequence of a local disease, and is of two kinds. One is where every part of the body sympathizes with any one part stimulated, as the sympathetic fever in consequence of local inflammation, as also eating substances that disagree with the stomach, convulsions from worms, teething, &c.; or, secondly, where particular parts, being stimulated, more readily produce universal sympathy than any other. Constitutional sympathy may arise in many cases from local sympathy, and not from the effect of the first injured part. This is very remarkable when the sympathizing part is a vital part, though the first injured part be not vital. If the stomach sympathizes strongly with any part of the body, this sympathy of the stomach produces a morbid state of the constitution. In universal sympathy there appear three stages, but all equally belonging to this principle; 1st, inflammatory fever; 2d, hectic fever; 3d, dissolution. These take their rise from the different stages of the local disease. There may be marked a fourth, which may be called nervous, spasmodic, or hysteric ; but this is not particular to any one of the states of the local disease from which the others arise, but from peculiarity of constitution, and sometimes it exists when the others do not. Local or partial sympathy is found more in old than in young; whereas universal sympathy is more in young than in old. Sympathy is less determined in young persons, every part being then ready to sympathize with other parts under disease. This is re- * [Of this kind also are the actions of membranous muscular cavities as the heart, stomach, or intestines, when their lining membranes are stimulated, and of the muscle of the skin in animals when the skin is irritated.] OF SYMPATHY. Ill markable in the teething of children, for in them universal sympathy seems the first mode of sympathy arising from local irritation. When a local disease takes place in a part when the patient is very young, it is capable of giving a general disposition to sympathize, by which means symptoms become more uncertain than in those of more advanced age, often putting on the appearances of a great variety of diseases. As the child advances, the power of sympathy becomes partial, there not being now in the constitution that universal consent of parts, but some part, which has greater sympathy than the rest, falls into the whole irritation ; therefore the whole disposition to sympathy is directed to some particular part. The different organs acquire more and more of their independent actions as the child grows older. We find in children the symptoms from sympathy often more violent than those of the parts affected. In adults when cutting teeth there is only an affection of the part, or only a continued sympathy, that is, a swelling of the cheek, &c. In adults the pain is often very great, but in children the pain is little, and the action of the part moderate, but the action in the sympathizing parts is very great, namely, in the voluntary muscles. Sympathetic Inflammatory Fever.—In consequence of considerable local injuries, as a compound fracture, or operation of consequence having been performed, that accident or operation shall be followed by inflammation, suppuration, &c. In consequence of this local injury fever shall arise in the system, which is universal sympathy, commonly called symptomatic fever. Convulsions often arise from considerable local injuries called irritation. Permanent contractions are also often the consequence of local injuries or irritation, as tetanus. If another mode of action takes place in the part sympathized with, namely the cure of the injury, then the inflammatory sympathetic fever will subside. Sympathetic Hectic Fever.—If parts have not a power to effect a cure, the constitution sympathizes in another way: it is teazed, as if conscious that the disease is incurable ; and this teazing constitutes the greatest part of what has been called hectic fever. But if this incurable part is removed, the hetic fever will cease. I have seen a wound in the knee keep a man awake several nights with pain and constant purging, and the patient becoming hectic ; and by amputating the part he slept well the same night without opium, the purging immediately ceased, and costiveness ensued. A man had a wound in the elbow-joint, and was affected exactly in the same way, the pulse quick and hard : within ten minutes after the removal of the arm the pulse became slower and softer. This universal sympathy, of whatever species, is greater when certain parts are diseased. The sympathetic fever will more readily take place from an injury done to the involuntary parts, as 112 HUNTER'S PRINCIPLES OF SURGERY.

the stomach, intestines, testicles, &c, than if the same mischief had been done to the voluntary parts, as the muscles of the arm, for instance. When vital parts are diseased, there is more sympathy among vital parts than among others. Universal sympathy is greater if the injury received is further from the source of life, namely, the heart, than near it, provided it be a part of the same nature in both cases. Sympathy is similar to sensation, action, motion, &c.: it can, and often does, cease instantaneously- Every sympathy ceases after the cause is gone, although its effects may remain, as tumefaction.* Some parts of the Body sympathize more than others.—The stomach appears to have this connexion with the body more than any other part. It would appear that the stomach was the seat of universal sympathy, sympathizing with every part of the body, and most parts of the body sympathizing with the stomach. Every part of the body seems to have some susceptibility of sympathy; but although there is universal sympathy between the stomach and whole body, yet the stomach sympathizes more readily with a complaint in the head than with one in the toe; more with the testicle than with many other parts. Also some parts of the body sympathize more readily with the stomach than many other parts, as the head, skin, &c. The skin sympathizing with the stomach is often very evident, from the effect some food has on the stomach, producing disease of the skin. A glass of cider in some shall produce a flushing in the face immediately; and spirits, in the end, we know, produce inflammation and suppuration over the whole face, called pimples, especially on the nose. But whether the stomach loses part of this property I am not certain. It appears that other parts lose that susceptibility to sympathize with the stomach, as the skin, for that part does not seem to be so readily affected in the old as in the young. The stomach sympathizes with the skin in many of its affections. Cold or wet feet will immediately affect the stomach. But the most striking instance is seen in the leech when its stomach is full of blood, by throwing salt on it, when, from sympathy of the stomach with the skin, it immediately rejects all the blood. The intestines, especially the upper parts, have also sympathies over the whole body. Cases of worms show this perhaps more than anything. Observations on Sympathies of the different Principles with one another, producing similar and dissimilar Sympathies.—Continued sympathy is more commonly similar than tho remote, as it is an extension of the samo action, and commonly in a similar part which can act alike, as indeed most parts do in most of their common

• [It often happens, however, that parts acquire a habit from long-continued sympathy, which does not cease qpon the cessation of the cause,] OF SYMPATHY. 113 actions, although the peculiar actions of the part may be dissimilar.* Thus, chancre on the scrotum, if it was to spread to the testicle, would produce the same mode of action in the testicle as in the scrotum, though it might at the same time produce effects peculiar to the testicle, as stoppage of the secretion, &c. But the remote, local, or partial, is both similar and dissimilar, varying according to two circumstances: 1st, According to the nature of the part deceased and the nature of the sympathizer. 2d, According to the species of properties in each part; as one property in the part diseased producing sympathy in another property in the sympathizer: disease in one part producing increased natural discharge in another part, which makes sympathy very complicated. Let us take sensation as an illustration: although we have no sympathetic sensation, it being wholly delusive, yet sensation is an absolute guide. We know that the sensations in the brain are not similar to any other sensations in the body, at least not similar to many of them; also the sensations of the stomach are unlike to many of the brain, if not to the whole of them; also that many of the sensations of the stomach are not similar to the sensations of other parts; also that all sensations of the stomach are not the same; also that an action of one part shall produce sympathy of another, whose mode of action is not similar: we must see therefore at once why the two modes of action become not similar, and why the sympathy is not similar to the cause, producing by this means another cause of complication, and consequently a variety in the first principles of sensation and action respecting sympathy. Again, difference of properties may produce dissimilar sympathies between two different principles, as the principle of life and that of action. For as sensation in one part may produce sympathy in a part whose actions are dissimilar from that other part, the sympathy produced will be dissimilar, and this resulting from the difference in the properties of the principle of action. Also when we consider that many parts have more modes of action than one, as the stomach, which has a variety of actions, and of course is capable of producing a variety of sympathies in other parts, or can sympathize in a variety of ways with other

* [To this head may be referred, 1st, Those sympathies by virtue of which parts become successively diseased in pairs, as two eyes, two similar parts of the skin, or two testicles. 2d, Those which give rise to disease in consequence of similarity of function, as ulceration of the cartilages, inflammation of the synovial membranes of joints, &c. 3d, Those which affect particular organs from forming parts of the same general system, as disease of the bladder affecting the kidney, of the uterus affecting the breast, or the spinal marrow of the brain, &c. And 4thly, Those which arise from similarity of structure, as inflammation of fibrous and mucous membranes, &c. We may observe, once for all, that any philosophical classification of sympathies is impracticable. Mr. Hunter has probably made his division of sympathies too complex; but he has amply redeemed this fault, if it be one, by the able manner in which he has treated the subject.] 10* 114 HUNTER'S PRINCIPLES OF SURGERY. parts, so that any one of these peculiar actions in one shall produce an action or sympathy in that suitable to the first action of the disease, which of course will be similar to the action of the diseased parts; while another action in the same part, and from the same principle, shall produce another mode of sympathy in the sympathizer ; when we consider all these, they will at first sight appear inexplicable: as an illustration, we may observe what a variety of sympathies are produced from one mode of irritation, as teething, or worms in the intestines. This connexion of every part of the body with the others, by sympathy, becomes one of the extensive principles of action in the animal economy, indeed is the basis of most of the compound impressions, affections, and actions. Similar Sympathy.—Sympathy must be similar to the affection of the part first affected when between parts whose affections are wholly similar; similar in action when between parts whose actions are wholly similar. Sympathy may be similar in disease when between parts endued with a variety of affections and actions, provided they are endued with the same affection or action, as irritation in one part producing irritation in another, which thus produces inflammation, as an injection into the urethra producing swelling and pain of the testicle. Continued sympathy, I believe, in all cases is similar to the disease, at least the action is so, even though it may spread to a dissimilar part. If inflammation attacks the diaphragm, and extends to the liver from continuity, that inflammation of the liver will be similar to that of the diaphragm. The same also if disease extends from the testicle to the scrotum, &c. Dissimilar Sympathy.—Sympathy is dissimilar when the affections or actions of the part impressed are not similar to the actions or affections of the part which sympathizes; thus, sickness at the stomach cannot produce sickness any where else; or, secondly, where parts diseased are susceptible of a variety of affections or actions of which the sympathizer is not; or, thirdly, even in parts where both the part diseased and the sympathizer are susceptible of the same varieties of stimuli and modes of action, which varieties in themselves are similar to one another, yet the sympathizer shall not be the corresponding affection or action to that which is excited in the part diseased; for example a medicine taken into the stomach shall produce flushing of the face or inflammation, though the stomach is liable to the same disease as that of the face, namely, inflammation. So that in this case the difference does not arise from the mode of action being different from that of the stomach, only that the face does not run on the same degree of action as the stomach. In inflammation of the liver the pain in the shoulder is different from inflammation, though the shoulder and liver are equally susceptible of inflammation. So that many parts have a variety of actions in themselves which are similar to some OF SYMPATHY. Hfi actions in other parts; therefore sympathy shall or shall not be similar to the action of the diseased part, being according to the stimulus applied to such part, or mode of action of the diseased part joined with the mode of affection. Therefore simple stimulus, action, or affection shall not only be the cause either of similar or dissimilar action, but both, according to the variety of affections and different parts that sympathize. A stimulus in the testicle shall produce sickness in the stomach, which shall produce vomiting, which is an action; so that a double and different compound sympathy takes places from the same stimulus. Of the simplest Sympathies.—In vegetables we evidently see actions taking place in consequence of actions having taken place in another part; but how far vegetables have a variety of properties and actions is not perfectly known; however, we can hardly doubt that they have a great many, for they produce a vast variety of effects, all these actions and effects arising from the principle of life. So that sympathies of vegetables may be complicated, and even dissimilar, but still more simple than the most simple animal. The succession of motions in a sensitive plant are no more than a succession of sympathies, or a succession of stimuli in consequence of those preceding. Here, then, we have an exact similarity in the actions of the sympathizers with the part first acted on. The most simple sympathy is perhaps to be found in vegetables, these being much more simple than the most simple animal. Vegetables have the same properties as animals without brain or stomach. Take away, therefore, the sympathies of the stomach with the body, and of the body with the stomach, and those between the brain and the body, reducing the sympathies of the animal to the simple properties of life, and an animal will be exactly similar to a vegetable; and this I know from experiments made on trees. The motion of the sensitive plant I have said is produced by a succession of simple sympathies: something like this may be found in the more imperfect animals; but no animal can be so simple in all its sympathies, though it may in some. I shall at present suppose that every part of an animal is liable to be affected by the stimulus of agreeable or disagreeable sensations, and the more simple the animal the more likely it is to be under the same simple sympathy. A polypus is the most simple complete animal, and therefore must be most similar in its sympathies; but I can conceive a child in the womb to be still more so, being capable of one stimulus only, namely, want in the system; and perhaps it has no sympathy even with this, as it has no demand on any part of its body for the supply. This simplicity of stimulus is found not only in the simple animals, but in some degree also in the more complicated. The similar sympathies may be compared to the unison in sounds. A polypus, though so simple an animal, is susceptible of four different stimuli, disagreeable and agreeable, propagation of the species, and want of repletion. In the last the stomach becomes 116 HUNTER'S PRINCIPLES OF SURGERY. the original sympathiser, and produces action in the other parts, so that here is a sympathy as in plants, but not so simple, for the stomach first sympathises with the whole body when it wants repletion, and afterwards by a reflex sympathy the body is called into action and its little arms are erected. Difference of Sympathies in the Sympathiser arising from difference in the mode of Impression.—Difference of affection and action of the sympathiser from that of the part affected does not always arise from difference in the nature of the two parts, but often from difference in the nature of the stimulant, or mode of impression; for a stimulant of one kind shall produce a mode of impression of its own kind in the part, from which shall arise a peculiar sympathy, while a stimulus of another kind will produce an impression of another kind, which of course wTill produce a sympathy of another kind in the part that sympathises. Thus, when the stomach is stimulated in a particular way, the head shall ache, which is often the case when something is taken which disagrees with the stomach; and if stimulated in another way the headache shall be removed, namely, by exciting vomiting.* There will be, therefore, a variety in the actions of the sympathiser, arising from varieties in the specific modes of action, created by different stimulants, which may also produce similar sympathy in dissimilar parts, for parts very dissimilar in their natural actions shall be put into similar actions by sympathy. When the stomach is stimulated in one way, an action shall be brought on in the muscles of respiration and of the belly for the expulsion of the irritating matter; or if stimulated in another way, sweating shall be brought on in the skin; or if stimulated in another way, universal debility takes place; a blow on the stomach may even kill. Hence it appears, that a stimulus of one kind produces sympathy in one part of the body, while a stimulus of another kind applied to the same part produces sympathy in another part, each mode of action in a particular part having other parts distinct from each other which sympathize with it. I should suspect that specific inflammations are not able to give to the sympathizer their specific virtues, though they may be liable to give them others. In continuous sympathies the affection is similar, but not in the remote. A swelled testicle in venereal gonorrhoea does not partake of the specific nature of the original disease. In a cancerous breast, the glands in the axilla will often inflame and subside again, which they would not do if they were affected with cancer. Sympathies of the Body arising from Affections of the Mind.—The living principle of the body sympathizes with the mind. Strong affections of the mind will produce involuntary motions, even of those parts commonly at the command of the will. This must be * [This illustration is incorrect; the headache is removed, not because another mode of stimulation, that of the emetic, takes place, but because the original one is removed ; thus spontaneous headaches terminate in sickness, and get°well.] OF SYMPATHY. 117 by means of the nerves, for the body has no connexion with the brain but by the nerves. Fear will produce action of the involuntary parts, as purging, discharge of urine, &c. I suspect that particular parts may sympathize more readily with the mind than others; therefore in such cases sympathies may be called local or remote, but they are, I believe, in most cases universal. Sympathies of the Mind, with the Living Principle.—The third principle, mind, is capable of sympathizing with the first, or actions depending on the living principle, for I should think that a state of the body often forms a state of mind; however, it is not so readily affect-ed by what does not produce sensation as by that which does. A man in pain not only feels pain as a sensation, but becomes depressed: or if the actions of life can produce sensation in any part, then the mind becomes affected, as when the whole body is in want of food the stomach sympathizes strongly with the whole, and the sympathy of the stomach causes a sympathizing mind. This is not sympathy immediately with the first principle, but sympathy with the sympathizer, or second, which, however, arose from the first. There are, however, instances where the mind sympathizes with the first, or life, for there are many instances where the mind is depressed without a sensible cause, called hypochondriasis, and also where the mind is light or easy without any sensible cause. I suspect that both these states arise from the living principle being either diseased or at rest. Sympathy of the mind with the voluntary parts is curious. If the voluntary parts are rendered useless, the will has no longer any power over them; it produces a state of mind which prevents the will putting the parts into action. Thus, when the tendo-Achillis is divided, the person cannot put the muscles attached to that tendon into action by the will; but as soon as union takes place and grows strong, the mind allows the will to take possession of its action over the muscles. Use of Sympathies*—Sympathies are designed for very important

* [To enumerate all the uses of sympathies in an animal body would evidently be impossible in the present state of science. Nothing is more certainly ascertained, however, than that every part of the frame is connected in some mysterious manner with the whole, and the whole with every part, in consequence of which a sort of community of feeling is established between all the parts and functions of the machine. This is most remarkably exemplified in those organs which are associated in some common function, as, for example, in the organs of generation, digestion, respiration, &c, which reciprocally act and react upon one another on all occasions, in health and in disease. Ascending to still higher generalities, as, e. g., to the great centre of organic life, the stomach, the brain, and the heart, the same relationship and dependence is observed to exist, still more strongly developed ; while these again may be regarded as so many primary foci, to which all the impressions of the body tend, and from which, by a sort of reflex operation, they radiate to the most remote parts of the system. A balance of power and action is thus established which it is easy to see must be of the most essential importance to the general economy of the animal, whereby the weakness of individual parts is reinforced by the reaction 118 HUNTER'S PRINCIPLES OF SURGERY. ends. They produce a communication between the three principles of the animal economy. The use of sympathy is often very evident. If there is an uncommon irritation in the lungs or throat, the muscles of respiration act with uncommon force, and the offending substance is thrown up. The irritation is frequently in the lungs, then it is transferred to the larynx, the muscles of respiration sympathize with the latter, and cough is excited either to get rid of the disease or of its consequence, which is increased and morbid secretion. In pregnancy the breasts become swollen, preparatory to their secreting milk in parturition. In labor the uterus is stimulated by the child, now become fit for expulsion, and the muscles of the abdomen sympathize with the uterus. Sympathy in diseases, by becoming the symptom of disease, often leads us to the cause, especially when the cause is in a deep-seated part, as the pain in the knee when the hip-joint is affected. We find that the sympathizer in some cases relieves the part irritated or under diseased action,as the testicle relieves the urethra; but there appears to be nothing gained by this, as the sympathy is the worse disease of the two. By the sympathizer often relieving the part diseased, and sometimes even curing it, it becomes similar to a constitutional affection becoming a local one, as in the gout; and, as in the swelled testicle from gonorrhoea it often changes sides almost instantaneously, it is in this exactly similar to gout.

of the whole, or, on the other hand, the over-action of one organ divided and broken by participation with another. Upon this principle it is, also, that one disease becomes the cure of another, and that revulsives and counter-irritants operate. This consent of parts, or interchange of sympathy, in virtue of which the parts of a complex animal body vibrate, as it were, in unison, pre-eminently distinguishes an organized being from any work of human art, especially when we add to this the further fact that it carries within itself its own resources of repair whenever it is injured. The full perception which Hunter had of this extraordinary co-operation of parts led him to employ a language borrowed from the operations of the mind, as if consciousness resided in an animal body, and was capable of directing its operations as it were by anticipation. (See pp. 29, 49, 54, 58, et passim.) The prevailing opinion is, that this connexion of function is established by means of the great sympathetic nerve, which is supposed to accompany the arteries in their most remote ramifications. Whether this is so or not is not susceptible of proof; we may at least venture to say that our knowledge of this set of nerves has hardly kept pace with other branches of physiology, and that in fact our actual knowledge of the subject is exceedingly imperfect. In the greater number of cases the intervention of the brain or spinal marrow seems to be an essential condition to the propagation of sympathy; and probably in those cases where this is not necessary, the same condition is fulfilled by the ganglionic masses of the sympathetic nerve. Nothing certain, however, can be affirmed on this subject. Some physiologists have excluded from their definition of sympathy all those phenomena which depend on obvious anatomical connexion, functional relation, or continuity of structure, restricting the terra to those cases only in which no functional or mechanical connexion is to be traced. I apprehend, however, that this distinction is not tenable, and that these two sets of phenomena will be found to depend on the same principle, and insensibly to merge in one another.] OF SYMPATHY. 119 Some sympathies are opposite in their action to the original action • pain in the liver is depressing, that in the shoulder rousing. Nature is incapable of sustaining the former, and sets up the rousing pain in the shoulder to continue life. Delusion.—A simple sensation in the mind of a local disease in the body which does not correspond with the seat of the disease itself has, I believe, been always referred to the principle of sympathy. Thus, sensation of pain in the shoulder from disease in the liver has been always supposed to arise from the shoulder sympathizing with the liver. The sensation of the glans penis from a disease or irritation in the bladder has been referred to the same cause. But I believe it is a delusion in the mind ; for the nerves of the part are not the seat of the disease, and irritation could not communicate to the mind the sensation of pain in the part affected, excepting they (the nerves) take on the same action, which they must do when they produce the sensation of pain of that part. But if the nerves of the part which is the seat of sensation in such cases do not act at all, it cannot be called sympathy. That there is such a delusive principle in the animal economy we see every day, and that it not only exists between mind and body, so as to lead us astray from the real subject, but between the mind and other bodies with which it has no immediate connexion, not even by the common senses. But we must allow that certain sensations can form a peculiar state of mind, called a sympathizing mind, for we are capable of transferring the sensation of another person to ourselves, which is like a dream. A delusion in the mind is an object appearing to be where it is not. To account for this delusion in sensation in ourselves may be difficult, but we may conceive it to be in this way. We may suppose that when the seat of sensation in the brain only takes on part of the action of sensation in the brain, it may be in this way: Suppose E, (PI. I. f. 3.) the brain; A B, two portions of the brain; G H, two nerves; F, communication between these two nerves; C D, two different parts of the body. The nerve G is inserted into part of the brain A; the nerve H into the other part B. F is a communicating nerve between G and H. A and B are the two parts of the brain to which sensation from C and D is conducted. C is the disease or part impressed. But from the connexion between C and D, by means of the nerves G F H, B will become the seat of action of the nerve G as well as of the nerve H, and the sensation be in part referred to D as well as to C. For if the nerve H is stimulated, in consequence of these connexions, to take up part of the action of the nerve G, and B is sensible of it as well as A is of the sensation of C, then the sensitive principle of the nerves A B is made sensible of both the disease of the part of impression as also of the sympathizer D, which become the two impressions in the sensorium. If anything stimulates G, part of the action is communicated to H; this goes on with the action to B, so that both A and B become sensible of the disease 120 HUNTER'S PRINCIPLES OF SURGERY. C. If there is disease in C, the mind is made sensible of it, because G always communicates the sense of C to A; but if a small portion of it is brought over to H, and this nerve carries on the action to B, B becomes sensible of it also, and B refers it not to C, but to D, because it is to that point that it has been accustomed to refer all its sensations. I do not know whether this explanation may be the true one or no, but it is one mode of explaining how we may feel both the disease and the part of sympathy. But how is it in those cases where the sympathizer takes on the whole action, affection, or sensation ? In this case we must suppose that not only a part but the whole of the sensation passes by the communicating nerve F to B, and thus the disease appears to be in D only. But it is possible that nervous sympathy is not affected by the nerves communicating with one another in the body, but from their connexions in the brain; as from the point B sympathizing with the point A, taking on the whole of its action, and referring its sensation to D.* Delirium.—It will be very difficult to prove whether delirium is a disease of the brain or nerves ; it appears equally easy to prove that it is from one as from the other. A delirium is a dream arising from disease, whether the dream is in the brain itself or in the body; only it is worthy of consideration, as dreams arise from sleep, and as a delirium is a diseased dream arising from what may be called diseased sleep, whether it may not be first necessary to give a short definition of sleep. Perfect sleep is a cessation of susceptibility of sensation, and of course of all its actions; the consequence of which is a cessation of consciousness in the animal of its own existence; and also, of course, of the consciousness of the relation it bears to itself and every other thing. But whether this cessation of the susceptibility of impression arises from the brain not then having power to receive impressions of the actions of nerves, or whether the nerves are not then capable of acting or conveying their action to the brain in the state of sleep, is not so easily determined. Dreams are actions of the mind in sleep; therefore may be inde- * [Thus, if a branch of a nerve be irritated (being in connexion with the spinal marrow), it is capable, by a reflective operation, of exciting all those musclea supplied by the trunk, although if the spinal marrow be destroyed this effect does not take place. Sympathies of simple sensation are probably as real as sympathies attended with visible action, and to be referred to the same general law. This appears from the same cause producing one or both effects, according as the cause is less or more intense. Thus toothache and tic-douloureux will occasion pain or inflammation of the face ; diseased hip will produce pain of the knee, and, as 1 have frequently seen, inflammation of that part; gonorrhoea will occasion pain or inflammation of the testicle ; disease of the bladder pain or morbid change of structure in the kidneys. Many other examples might be adduced to show^that the same cause is capable of producing simple pain or pain accompanied with visible effects : which is evidently inconsistent with the opinion which ascribes simple sympathetic pain to a misdirection of the mind.] OF SYMPATHY. 121 pendent of any immediate information or impression, but are always independent of the relative connexion between body and mind, or consciousness of the existence of that relationship between the two. For the connexion between the two enables the mind to distinguish perfectly what is sensation and what is only thought, without which all would be a dream. In a delirium, as in sleep, we find the susceptibility of external impression lessened. Whilst sensation is continued sleep is kept off; delirium may be also lessened by arousing the mind from that particular state by external impressions; so far delirium appears similar to dreams, but it widely differs in other respects. In natural sleep the more the brain puts on that peculiar state the less we have of dreaming; but the more the other state is put on the greater the delirium. Dreams often do arise from sensations of the body being conveyed to the brain, it being in an imperfect sleep; but the consciousness of the connexion between our own body and our own mind being cut off by the state of sleep, the sensation may or may not be referred to our own body; it may be referred to some other body.* In some cases it is not referred to the part of the body where the impression is made: and the same thing happens in delirium, where the connexion is cut off; these not distinguishing between real sensation and thought, what the mind thinks about appears to be real. But even where the mind is in full possession of the consciousness of its connexion and relationship with the body, we have in some cases this delusion, as the appearance of the turning round of the objects about us whilst they are really fixed, and that in consequence of our having turned about quickly; giddiness from going to a height, or from riding backwards in a coach. Delusion is also an effect of intoxication and disease. Whilst awake and in health, impressions produce sensations, which are conveyed to the brain, and from these the mind reasons: but suppose the mind to

* [One of the most remarkable properties of dreams is, that we have no idea of time or place, or sometimes of our personal identity; in consequence of which we commit the most ludicrous anachronisms, imagine ourselves dead and alive, or in two places, at the same time, or else that our spirits have transmigrated into some other bodies. In consequence of the absence of external perception in sleep, the ideas and associations of the mind acquire an overpowering vividness which lead3 us to mistake them for realities; while the absence of reason and volition permits the imagination to revel in its own creations under the simple guidance of association. There are, however, many phenomena respecting dreams, delirium, and that variety of the former called somnambulism, which do not admit of any plausible explanation : the will, the senses, and voluntary motion are still exercised, under certain modifications; whilst it must be in the experience of every one that the reasoning faculty is still also capable of exerting itself, so as in some rare cases to engage in, and even to accomplish, the analysis of complicated problems which it could not have achieved during its waking 6tate. There is one point in which pure delirium and sleep differ from insanity. Persons may be roused by a strong impression from the former to a right perception of their situation, whereas in the insane person truth and error are inextricably blended together, so that when seen side by side they are not distinguishable by the patient ] 11 132 HUNTER'S PRINCIPLES OF SURGERY. have lost, or as it were forgot, its former connexion with our body, then the above false reference takes place. A gentleman came into this country in 17—; his memory was imperfect, and a particular kind of delirium began whenever he was going to sleep, but afterwards continued whilst wide awake ; and for a week before his death he was not quiet from this delirium a moment, but whilst his impressions were forced on him by external objects. His delirium was of this kind; he was constantly talking of former circumstances of his life, but referring them to the present moment and to some other person. There was a revival of past ideas in his mind, but from a want of connexion between his mind and his body, he was not enabled, by his present impressions, to infer how little relationship they bore to the present time, or to those persons to whom he referred them : at the same time, it really appeared more a want of connexion between the mind and the body than the mind itself being hurt, for he determined rightly what should be done in those circumstances which he supposed present, and would express his sentiments in really elegant language. That it depended more on want of connexion than on disease of the body, appeared, from his being sensible of impressions, and referring them to the part where they took place, but supposing that to be in any other body than his own. Thus, he would tell his nurse or the bystanders that they were hungry or thirsty ; but upon offering food or drink, it appeared plainly by his eagerness that the idea had arisen from a sensation of hunger in his own stomach. He would show great signs of distress or anxiety, which he would say was because his nurse wanted to go to the close stool, but was restrained by his presence ; and this from his sensations also. He had a violent cough, in which he would sympathize with some bystander, proceeding in his story after the cough, no otherwise disturbed than by sympathizing with the person whom he thought so unfortunate as to have it. The objects about him were more to him than his own sensations. A gentleman who was fond of his bottle referred all his Own weaknesses and feeling, as he became intoxicated, to those around him; and upon his going home would insist upon undressing all his family and putting them to bed, declaring that they were too drunk to do it themselves; and this happened not only once, but whenever he was intoxicated. I myself once experienced what I have since thought must have proceeded from this want of connexion between the mind and the body. I was reading a remarkable case, and reasoning with myself upon it, when I found the letters and words made an impression on the retina, but that I was incapable of affixing a meaning to them: this I thought might proceed from want of sleep ; but that was not the case: I tried repeatedly, but without effect, and at last I went to bed, from which I did not move for three weeks, a violent affection of the head following this extraordinary circumstance. It may not be amiss to say, that the case I was reading was that of the late Mr. Foote, who was not OF SYMPATHY. 123 able to command his attention to more than one action or circumstance at a time: thus, if he took his snuffbox out of his pocket and held it in his hand, it was all very well, until he attempted another action, such as taking a pinch of snuff out of it, and then the box fell immediately out of his hand : in fact, he was going back into a state of second childhood, for a child is not capable of commanding his attention to more than one circumstance or action at a time: give him a stick to hold, and call his attention to another object, and the stick will be dropped; for it is by habit we become capable of attending to several actions at a time. If a person is blindfolded and put into a coach, he will think he is riding forwards though really moving backwards. An impression from any part, either healthy or diseased, may be conveyed, yet there may be no consciousness of the mind from which part of the body it was conveyed, the mind having full possession of the impression, and a perfect idea of it, but having nothing to direct it right in its reference of it. It must refer it somewhere, and is more likely to refer it to another than to itself. Thus, A (PI. I. fig. 3.) does not refer the sensation to C as a cause, nor will B sympathize with A so as to refer it to D. A gentleman, a medical man, dreamed he had given a patient too strong an injection for gonorrhoea, and that it had produced a total stoppage of urine: he awoke, and found an erection of the penis, and that he could not void a drop of urine. Here was an impression without the consciousness, and he referred the impression to another person. A gentleman, upwards of ninety years old, suddenly lost his senses, and in consequence of this there was a reference of all the ails which he might be supposed to feel to his wife, who had been dead some time, but who he now thought to be alive, and ordering the utmost silence to be preserved, lest by noise her illness should be increased. The new-born child has probably sensation without this consciousness. The contrary takes place when a person refers the sensations of others to himself, or when the idea of sensation is supposed to be sensation itself, as happens in those who are affected by animal magnetism. I was asked to go to be magnetized, but at first refused, because the spasm on my vital parts was very likely to be brought on by a state of mind anxious about any event. Thus, at my country box I have bees, which I am very fond of, and I once was anxious about their swarming lest it should not happen before I set off for town; this brought it on. The cats teaze me very much by destroying my tame pheasants, partridges, &c, and rooting up my plants. I saw a large cat sitting at the root of a tree, and was going into the house for a gun, when I became anxious lest she should get away before my return ; this likewise brought on the spasm; other states, where my mind is much more affected, will not bring it on. Now I feared lest my anxiety for the event should bring on the spasm, and that should be imputed to animal magnetism. But considering that if any person was affected by it it must be by the imagination being worked up by attention 124 HUNTER'S PRINCIPLES OF SURGERY. to the part expected to be affected, and thinking I could counteract *iiis, I went; and accordingly, when I went, I was convinced by the apparatus that everything was calculated to affect the imagination. When the magnetizer began his operations, and informed me that I should feel it first at the roots of my nails of that hand nearest the apparatus, I fixed my attention on my great toe, where I was wishing to have a fit of the gout; and I am confident that I can fix my attention to any part until I have a sensation in that part. Whenever I found myself attending to his tricks, I fell to work with my great toe, working it about, &c, by which means I prevented it having any effect on me. CHAPTER XL

OF LOCAL AND CONSTITUTIONAL DISEASES.

Difficulty of distinguishing between strictly local diseases and local diseases arising from constitutional affection.—Diseases constitutional;—local;—mixed.— The first universal, as fever;—or constitutionally local, as gout.—Local diseases.—Mixed diseases.—Diseases common or specific.—The latter do not always depend on a specific cause.—Of diseases peculiar to ages.—Effects of climate on diseases;—of seasons;—of temperature;—of the moon.—Of humours, erroneous notions of them ;—effects of substances contained in the v blood ;—experiments of injecting medicines into the blood ;—no specific diseases produced.—Of diseases supposed to arise from humours.—Of hereditary diseases ;—hereditary nature of natural and of acquired properties ;—hereditary dispositions;—latent hereditary principles ;—similarity of children to their parents ;—dispositions hereditary, but not diseases ;—more permanent than accidental dispositions;—scrofula;—gout;—supposed hereditary.— Symptoms of disease local or universal ;—variation of local symptoms ;— universal symptoms affecting the circulation ;—secretions ;—nerves.—Combinations of symptoms.—Irregular symptoms.—Delusive symptoms.

It may be difficult in all cases of local diseases to distinguish between one truly local and one arising from the constitution ; that is, one arising entirely in the part diseased, and one arising entirely from the constitution. For as one can and often does affect the other, which may be called mixed, it becomes the more uncertain where the disease originated.* Diseases may be called constitutional, local, and mixed. Diseases may be originally constitutional and originally local; that is, diseases may take place in the same person from constitutional or local

* [Mr. Abernethy, in speaking of the evil effects arising from the separation of medicine from surgery, makes the following observation : "The effects of local disorders upon the constitution have in consequence been too little attended to; and, indeed, I know of no book to which I can refer a surgical student for a satisfactory account of those febrile and nervous affections which local disease produces, except that of Mr. Hunter." See his Essay " On the Constitutional Origin and Treatment of Local Diseases."] OF LOCAL AND CONSTITUTIONAL DISEASES. 125 causes, and be totally independent of each other; but they may affect one another. The first, or constitutional, is either a universal action of some kind, as fever, or where there is a universal susceptibility for an action, but the action is local. Therefore they are divisible into two kinds, 1st, universally constitutional, and 2d, constitutionally local. Universally constitutional is when there is universal action of some kind, as fever, where every part of the body is under some diseased action, which will be according to the nature of the influence which produced the fever, as inflammatory fever, putrid fever, &c. Those arising from external influence will in some degree reduce all constitutions to some one mode of action; and whatever difference there is between one and the other must only arise from a peculiarity in constitution. If an inflammation is produced in any part by violence, it will always be as the constitution is. If a man has a fever, a cut will partake of the disease, and the inflammation will be erysipelatous,* or so on, according to the fever. But if the fever is of some specific kind, superadded to the nature of the constitution, as small-pox fever, a cut will not partake of the specific quality of that fever, but will be exclusive of the specific quality. Nor will a cut on any part of a pocky patient be venereal. Constitutional diseases are of various classes, which are known by their effects. A constitutional disease is a universal diseased action, as fever, every part taking on more or less of the diseased disposition. Such diseases, I apprehend, have no disposition for local action, though it is commonly supposed they have, as where fever produces abscess. This I hardly believe, though an abscess may form in the time of that fever, and is caused by it, or is an effect of that fever; but it is not an act of the constitution, according to our third division, therefore does not relieve the constitution of that fever. What I call an act of the constitution relieves the constitution, as gout falling on a part; but in abscess from fever it is only that this part has been so disturbed in the time of the fever that it has gone into inflammation and suppuration. The second of the universal is the constitutionally local, that is, when there is universal susceptibility of body to produce peculiar local complaints, but not the action, till disturbed ; requiring an immediate cause, which may at the time be either universally disturbing, as fever, or in the part only, as an accident. Thus the whole constitution may be affected with a gouty disposition, but the disease becomes local and is cured. We see constitutional or univer-

* [There are many exceptions to this observation, as, for instance, in several cutaneous diseases, gout, rheumatism, &c. These diseases may exist in an active state in some parts of the body at the same time that common inflammation is produced in other parts by accidental injury. On the other hand, the erysipelatous inflammation seems to give way to common phlegmon when incisions are made into erysipelatous parts.] 11* 126 HUNTER'S PRINCIPLES OF SURGERY. sal diseased affection excite local, as fever exciting scrofula, not as a termination of that fever, but because the part affected was partaker of the universal affection, and being disturbed by that universal affection or action, it took on the mode of action it was most susceptible of. It would do the same thing on being locally disturbed; therefore, as to its diseased action, it is the same whether it is disturbed as part of a whole, or only by itself. The scrofula goes no further than a susceptibility for diseased action, until it is brought into action by the local injury or constitutional fever. Perhaps there is no term so vague or undetermined in the mind as the term constitutional. Universal action of every kind may be called constitutional, even when arising from some local cause, which I have called one of the mixed; or one capable of producing local effects, which we have also called one of the mixed. But a true constitutional disease is one arising, as it were, spontaneously in the constitution, partaking of the nature of the constitution itself. Local disease I would consider in two lights; 1st, When it is a natural local action, being a kind of violence on a part, there being no constitutional local affection. In this case the disease takes on no specific quality of the constitution, either from the constitution having none, or the disease not being affected by it, being such as either arises from itself in a part from a local cause, and may take place in any constitution, or may be produced by accident or violence where the constitution was never affected. 2d, Which will more properly come under the head of mixed, where the local affection either affects or is affected by the constitution. The mixed may be said to partake of the first and second, and is often the consequence of either, namely, original constitutional producing local, or original local producing constitutional; therefore they are often of two kinds, and such as may be called secondary actions either of the constitution or part, as universal sympathy with local disease, yet not what generally comes under the idea of common sympathy, as sympathy of part with part. Of the mixed, the first kind is where original constitutional produces local; the second where it influences local already produced. Therefore this kind is divisible into two species. It may be difficult lo say certainly when a constitutional disease really produces a local; but it may be set down generally that there will be a distance as to the time of appearance of the two diseases. The first of these two species is of various kinds, perhaps belongs more to specific diseases than to common, and is where the constitution from its nature produces a local one, and is necessarily relieved by it, by what I have called an act of the constitution. Of this kind are small-pox, measles, fevers producing critical abscesses, erysipelatous fevers, gout, &c, and on this is founded the doctrine of revulsion. Local diseases produced by an act of the constitution may be illustrated, I think, by the growth of plants. A plant or tree appears to have a disposition and power of producing either only a OF LOCAL AND CONSTITUTIONAL DISEASES. top shoot, or a number of shoots, called branches, which are according to the nature of the plant. If the top is cut off, then a new branch sprouts, and it serves as a top; so that the disposition is taken up by some other part most susceptible of action. The same thing happens in those plants which grow by branches. So that the removal of a part in action gives the disposition of action to parts not before disposed to act, but next in order of susceptibility. v The second of the mixed is where the original local produces constitutional, and which may alter the constitutional disease already existing, or cure it. This may be of three kinds. 1st, The immediate; 2d, Less determined as to time; 3d, The remote. Of the first there appear to be two; of the second but one, though it may appear in different forms ; of the third probably only one. Of the immediate we shall reckon that which is called symptomatic fever. Delirium I shall reckon the second, though it is not always the second as to time. The third or remote, is hectic, to which may be added symptoms of dissolution, which last stage may be the consequence of either of them, or of any other disease. The first of these is generally called symptomatic fever, but I choose rather to call it sympathetic inflammatory fever. It is sympathy of the constitution with the first stages of local disease, which is the action of alarm on the constitution, rousing up its powers to produce action. The second, or delirium, appears to arise from an affection of the brain or sensorium, producing sympathy of action of the brain with the nerves of the part; not sensation, as headache, but an action producing ideas without uniting sensation, which is therefore delusive. The remote, namely, the hectic, is a sympathy of the constitution with local disease, but sympathy of another kind ; it is sympathy with the operation of an incurable disease, where the constitution is conscious of inability of the part to perform a cure, by which means the constitution is at last, as it were, worn out, producing dissolution if not removed. Dissolution is the last stage and consequence of all, whether local or constitutional. Diseases are common or specific.—All diseases are either common or specific, but it is more than probable that most diseases have some specific qualities. A common disease is such as will attack every constitution, and perhaps every animal, and rather appears to be an increased action, as common inflammation, common inflammatory fever, &c. Many diseases may be reckoned specific in their mode of action, though not in their cause. An ague is a specific action, but its causes are various. Gout is a specific action, but its causes various. Cancer is a specific action, though its immediate causes are various ; but it is capable itself of becoming a true specific cause, 128 HUNTER'S PRINCIPLES OF SURGERY. by forming a poison. The cause of scrofula varies, though its action is specific. The remote cause of all is a greater susceptibility of such actions. A specific is a peculiar mode of action, differing from every other mode of action. A true specific disease is one that probably cannot arise but from one cause, and which probably belongs only to morbid poisons ; for although gout, scrofula, ague, &c, may be ranked among the specific, yet they can and do arise from a thousand causes. There seems a specific susceptibility for those diseases in those that have them. But in poisons there must be a specific cause, which may be attended at the same time with specific susceptibility of such, as some have a greater tendency to small-pox than others. Specific diseases are such as we cannot increase, for they always act with the full force of the readiness in which the constitution is at the time. If the constitution can be made more susceptible of action, the action will be increased. Every specific disease has two modes of action—namely, the common and the specific,—joined to it. There are specific inflammations, specific suppurations ; or, in other words, there are inflammations and suppurations with specific properties, or which have specific properties superadded ; thus, in small-pox there is common inflammation, with the specific qualities superadded. Specific diseases may be either universal or local; universal, as fevers of particular kinds ; local, as scrofula; others are mixed, as agues, rheumatism ; and these admit of cure from a variety of medicines. A circumstance worthy of notice takes place with respect to local specific diseases; parts appear susceptible of them as to take on their action so readily, that were it not for another very curious circumstance we might soon expect them to spread over the whole body; but the favourable circumstance I refer to is where the disease is spreading very fast, affecting parts which the disease has not yet touched, whilst in the centre this diseased action no longer takes place. Those parts which have already suffered this action appear to have lost their susceptibility of it, whilst the surrounding parts are contaminated by sympathy with those parts already affected : this property belongs to many, as erysipelas, herpes, &c. I have seen the same thing take place in ulcerated bubo, spreading over the whole belly and thigh, but healing in the centre. Another circumstance is to be added to what I have mentioned as hindering the disease from extending over the whole body, which is, that the constitution itself alters or loses that peculiar susceptibility before such an event takes place. Different parts differ very much in their power of resisting diseases, as well as in the power of curing themselves, or getting rid of the diseased action and putting on a curative one: this seems to be according to the strength of the circulation in the part; where this is less the power is less; thus, there is greater power of resis- OF LOCAL AND CONSTITUTIONAL DISEASES. 129 tance in a muscle than in a tendon. But in specific diseases I should suppose there is little difference in this respect, in consequence of a difference in structure, although we know that specific diseases affect some parts more than others, as the small-pox affects the skin; the measles, the skin and surface of the lungs: hoopingcough and hydrophobia, the throat; &c. Diseases peculiar to Ages.—Particular ages have their particular diseases. These diseases peculiar to age are perhaps more of the specific than of the common kind; and age is little more than a natural or remote cause, there being some immediate cause acting so as to produce the disease, as in scrofula. But this is not the case with all of them, e.g. cancer, for this appears often to arise without any peculiar immediate cause. How far particular ages are more or less susceptible of particular poisons we do not know. The age of man may be divided into three parts: 1st, The age of growth; 2d, The stationary age; 3d, The age of decline. The first and last are absolute, but the second is not so easily ascertained, it not being very easy to say where the first ends and the last begins. The young subject and old are more susceptible of many diseases than the full-grown, or stationary, but they are not subject to the same diseases. The young are more susceptible of sympathy, both universal and local; more susceptible of scrofula than the middle-aged, but particularly more than the old: and this scrofula may produce consumption, which we know is peculiar to youth. Children are more disposed to have affections of the bowels, and worms, perhaps, from a peculiarity in their way of life. They are also more subject to water in the head than those who are older. The young have few affections of the mind, excepting those arising from natural passions, or immediate sensations of the body. The middle age would appear to have but few diseases peculiar to it, excepting nervous affections and hypochondriasis, &c. 1 he middle age gets into an imaginary region, a region of romance, which produces diseases of the mind, and also affects the body. However, it is, as it were, accidentally affected with the diseases both of youth and age, with which it is gradually intermixed. 1 he foundations for the diseases of old age are often laid by intemperance during the middle age. In the old we have perhaps as great a variety of diseases as in the young. In the old the power and necessary action are not well proportioned, even in health, much less, therefore, in disease. 1 his produces a degree of irritability often increasing inflammation, and terminating frequently in mortification. In the old we have the gout, which seldom takes places in the young. Cancer ^ peculiar to the latter part of the middle age, and still more to the old. Gallstones are to be found chiefly in the middle-aged and old. Ossifications of arteries are rarely found in young persons. Ihe blaader becomes less disposed to stretch, and more irritable; hence oia people make water oftener than young. The prostate gland is more subject to indurations. The mind gradually becomes more 130 HUNTER'S PRINCIPLES OF SURGERY.

attached to [Quaere, detached from ?] this world and the things that are in it the nearer it approaches to a separation from it. Effects of Climate on Disease.—Climate in general only becomes the immediate cause of disease; however, it isf sometimes sufficient to produce the whole disease. Climates are of three kinds: hot, cold, and temperate. Hot climates carry on the natural operations both of animals and vegetables with much more rapidity than either of the others. It is almost impossible to rear young animals in cold weather; therefore most animals bring forth their young in spring and summer. Animals of the same species do not grow to the same size in cold climates as in warm. It is almost impossible to fatten an animal while it is kept in the cold. Warmth produces action beyond its power of generating strength. Parts more readily yield to any power in summer than in winter. Mr. Jones, the inventor of the machine for correcting distorted spines, observes that they produce more effect in summer than in winter. Hot climates produce diseases in the liver, but these diseases are more frequent in the West Indian islands than on the continent of South America or India.* They also produce violent vomitings and other disorders in the stomach; also violent affections of the bowels: and fevers and diseased actions, like the natural, are much more rapid than in temperate climates, it being no unusual circumstance for diseases to run through all their stages in a few hours, ending in death, which is speedily followed by putrefaction. Heat produces indolence in the voluntary actions, which is injurious to health, but generally increases the involuntary action or actions of life, which is always hurtful. Cold climates retard many actions, both of vegetables and animals ; but cold, when only in a certain degree, and continued for a certain length of time, excites action; but that is the action of strength, the action of resistance or defence, not the action of luxury or ease. Cold climates produce their diseases, though it would appear that they have not equal effects with warm, nor are capable of producing such variety. Whatever diseases are produced by cold are not so rapid as those produced by heat; and after death putrefaction does not take place so rapidly. We may observe a curious gradation in this process; in cold climates, after visible death, absolute life will remain for some time ; the muscles will retain their power of contraction, and the blood be kept from coagulating. But in hot climates death is as rapid as disease ; for it is action that consumes life. In cold the action is less: in heat it is so great that the body can hardly support it, and death comes on. Cold climates lead to voluntary actions, which generate heat, and this is much more healthful than heat derived from external sources. In temperate climates there is perhaps a greater variety of

* [The very reverse of this observation is, I believe, the fact; see p. 86.] OF LOCAL AND CONSTITUTIONAL DISEASES. 131 diseases than in either the hot or the cold ; for the temperate is a very irregular medium, sometimes very hot, sometimes very cold, and often in the middle state ; and these changes are not at regular periods. This irregularity produces some irregularity in the wetness or dryness, so that in such climates we have a great mixture. These changes] in temperate climates give rise to scrofula, colds, &c, which are the forerunners of a thousand diseases. Agues are also much more frequent in temperate climates. Seasons.—Seasons which arise from the variations of heat in a climate, produce diseases which will be in some degree similar to those both of hot and cold, and also temperate climates ; for seasons are, as it were, a change from one climate to another. Seasons have besides, diseases peculiar to themselves; they produce an increase of old diseases, arising simply from the change, and call forth those diseases which only want an immediate cause to produce them. The spring and autumn are two of the most unhealthy seasons in the year : the spring the most so, although from reasoning alone, without observation, it is supposed to be the most healthy, and therefore people do in the spring whatever will allow of a choice of time, as inoculating, &c. This idea probably took its rise from observing vegetation, that at this time the plants appear to come into life and action. But, even in vegetables, this season is the most unhealthy ; blights much more frequently take place in spring than in summer. Of every disease that can be called constitutional, that is, where there is a strong susceptibility for such disease, we find spring becomes the immediate cause, exciting it to action; thus, scrofula shows itself, or increases in spring ; the same with rheumatism and scurvy; hence spring is said to set the humours afloat by those who are favourers of the humoral pathology. I should doubt much whether there is any diurnal influence on our body, further than that which the habitual modes of acting produces; consequently, I doubt if daylight or darkness produces any effect. It is, however, certain that the increase of action which commonly takes place in the day, increases diseased action, producing exacerbations in continuous diseases. It is probable, therefore, that it may bring on the paroxysms of those diseases which are periodical, and may bring on the first fit of a disease for the same reason. Effects of the Moon.—The moon has certainly considerable effects on the human body. We find it often become the immediate cause of diseased actions, especially those of the mind. Mad people are certainly more affected at particular periods of the moon than at other times. The full of the moon has the greatest effect: it not only affects those who have a natural predisposition, but also some who have had injuries done to the brain by external violence. A lamp-lighter, by a fall, injured his head: upon examination I found a fracture which appeared to run through the foramen magnum of his occiput; he recovered, but he was seized every spring 132 HUNTER'S PRINCIPLES OF SURGERY.

with a phrenzy at stated intervals, and this was found to be at the full of the moon. A gentleman had an anchylosed knee and ankle-joint from scrofula, and he is always deaf at the full of the moon, except in autumn, when his sores discharge plentifully. This effect of the moon is increased at certain seasons ; in spring it is greatest often. Intermitting and remitting fevers often arise, recur, or become exasperated about the time of the full or new moon, more especially in climates fitted for giving rise to such diseases.* Of Humours.—The term humour has been applied to the animal body, especially the human, both literally and metaphorically. When literally, it is used in two senses, either as expressive of an extraneous substance existing in the blood, or as meaning the blood itself. When used metaphorically it is applied only to the mind, and is therefore more applicable to the human than any other animal. Nothing can be more vague, nothing more unphilosophical, nothing more misleading in science, than to employ the same term to express two or more different meanings. In whatever sense the term is used, however, whether as applied to the mind or the body, it always is meant to express the cause of an unnatural or uncommon action or effect. At present we shall only consider humours in their literal sense, in order to ascertain how far the notion is just or imaginary. I have just said that the word is used in two senses, either as something in the blood, but foreign to it, or else as implying a vitiation, of the whole mass of the blood itself. Among physical people we find such expressions in common use as " the humours are afloat in the blood;" "sharp humours in the blood;" "the whole humours being in a bad state;" " the whole blood must be altered or corrected;" and a variety of such expressions without meaning. They even go so far as to have hereditary humours, as gout, scrofula, &c, and make us the parents of our own humours, saying that we breed bad humours. Accidents, or even the application of poultices, have been supposed to bring bad humours to a part, because the part in which the aceident happened, or to which the poultice was applied, would not readily heal. Humours are even supposed to gravitate to the legs slowly; and, in short, the whole theory of disease has been f built upon the supposition of humours in the blood, or of the blood i itself being changed. I cannot conceive what is meant, unless it be that a strong susceptibility to a specific disease exists; as small-pox may bring on scrofula, or a strain the gout; if in these cases by humour is meant a susceptibility of either of the diseases, I can conceive that any kind of accident may bring it on. The small-pox introduced may excite action, and so bring on the scrofula.

• [Dr. F. Balfour has fully confirmed this observation as to the effects of sollunar influence on the bilious remittent fevers of hot climates.] OF LOCAL AND CONSTITUTIONAL DISEASES. 133 I shall now consider the notion of humours afloat in the blood. If I have a just idea of the meaning of this expression, it signifies * something extraneous or foreign, something that does not belong to the blood itself. That foreign matter is received into the bloodvessels is certain, and that so received it produces disease is also certain ; but simply foreign matter being introduced into the blood, either produces no effect or no permanent and specific disease ; the constitution, or some part, can be disturbed only as the constitution or part would be disturbed from any accident. Medicines, applied either externally or internally, is a proof of this, for all enter the circulation more or less, therefore are in the state of something extraneous, or of humours in the blood. Indeed, chemical analysis ot the blood shows the existence of foreign matter, for it discovers substances that form no part of the animal, as sea-salt, iron, earths, &c; yet these substances produce no ill effects by their presence. The following experiments show the effects of foreign substances in the blood: . , , __, Experiment 1. I injected into the crural vein of a dog, towards the heart, a weak solution of sea-salt, which produced no effect. 1 then made as strong a one as possible and threw that in also, but no effect was produced. The quantity of salt thrown in might be about

^Ex^enmen^8.' I threw a strong solution of Glauber's salts into the vein of a dog—about two drachms of salt. It produced no effect. The dog ate and drank and had his stools as before. Experiment 3. Two ounces of a saturated solution of salt ot

^Exp^n^'-An ounce of water, in which a scrapie of borax was dissolved, was thrown into the veins without effect. ExTerlen 7. An ounce of vinegar and water, in equal proportions Tas thrown into the veins of a bitch half gone with pup S brought on an immediate disposition for miscarriage, which took place in about six or eight hours. vineo-ar Experiment 8 Water, rendered about as acid as the vinegar anfw'atTwlth vitriolic acid, was thrown into the veins, and pro-

Xe—9 lldto. The same experiment was made with

Ipf/su^ "ffects wh5n thr(T inth SX^X^tf ^m produce any ^^«™£*£$ bv repeating them, and increasing the quantities, a man may destroy hfs health, St even his life, by destroying the natural actions of the

^But all this is not producing any specific disease; it is reducible l <* 134 HUNTER'S PRINCIPLES OF SURGERY.

to the effects of local applications, which is similar to an accident, producing no specific or permanent disease but what an accident would do, nor lasting any longer than the application lasted. Experiment 11. I threw about two teaspoonfuls of a strong solution of opium, two parts water with one of opium, into the crural vein of a dog. The dog seemed to be very sensible of it at first, for he was extremely uneasy, and soon became convulsed, but did not lose sensation, for when touched he started and seemed frightened, and drew back his face when a hand was presented to it; so that irritability was rather increased. I then threw in as much more, which made him still more quiet, and in great measure produced loss of the use of his limbs, so that he could not stand; his breathing became slow and laborious, but his pulse very quick ; when he attempted to get up he reeled, and came down as if asleep or drunk. Experiment 12. I threw into the veins of a dog two teaspoonfuls of common gin. He showed no sense of uneasiness, but became soon vastly quiet, and not in the least irritable, showing no signs of fear when touched, He seemed wholly relaxed; his breathing was easy, and his pulse slow. He continued above an hour in this way and then began to recover. Experiment 13. I threw about two teaspoonfuls of laurel water into the veins of a dog. The pulsation in the vessels became tremulous; he seemed very ill, and could hardly raise his head, but he recovered. From these last experiments it appears obvious that many substances, having peculiar modes of stimulus, will, when taken into the blood, produce their effects there; but this effect will last no longer than the presence of the stimulus; and we shall find in general that their effects in this way are similar to what, they are when taken into the stomach. We find also, by the above experiments, that many substances thrown into the constitution by the veins produce the same local specific effects on the intestines with those produced by the substance when taken in by the mouth. Experiment 14. I threw into the veins of a dog an ounce of infusion of ipecacuan, made with five grains of the powder to two ounces of water. The dog immediately became very sick, and was retching before I could untie the mouth, and as soon as it was untied he threw up all that was in his stomach. He continued sick for some time, and gradually recovered. I can hardly suppose that the injection had gone beyond the heart, or even to it, when it began to act. Experiment 15. An ounce of infusion of jalap, made with twenty grains of jalap to two ounces of water, and steeped for twelve hours, was thrown into the veins of a dog. In less than a minute he vomited a little and then seemed well. Thinking that no more effect would be produced, I threw in the remaining ounce. This did not produce any vomiting, nor did he at first seem much affected; but at last he grew weak on his legs, lay down at times, and then rose again. About two hours after the infusion was OF LOCAL AND CONSTITUTIONAL DISEASES. 135 thrown in he had a stool, and after this another, which was loose. He remained sensible the whole time and then got well. Experiment 16. In a similar experiment the dog vomited, had some loose stools, and in a few hours got well. Although many substances do produce similar effects on the stomach and intestines when thrown into the blood as when taken by the mouth, as appears from the above experiment, yet this is not the case with all. In the second experiment, for instance, we find that Glauber's salt had no such effect when thrown into the blood as when taken into the stomach. In like manner, Experiment 17. An infusion of rhubarb, thrown into the veins of a dog, produced no effect but that of increasing the urine, which it did plentifully, Many substances thrown into the blood produce much more violent effects in this way than when taken into the stomach, and even cause immediate death. Experiment 18. I threw into the veins of a dog a little aether, and he died immediately. On opening the body the thorax had a strong smell of sether. However, this effect may depend on the strength of the medicine, as we shall see by the following experiments that the reason why death did not take place in experiments 6, 7, 8, 9, was the weakness of the solution. Experiment 19. I threw some common vinegar into the veins of a dog, towards the heart. He died before I supposed it could have got to the heart. Now vinegar, when diluted, as we found before, had no such sudden effect. In the same manner, nitrous and vitriolic acid, diluted, to about the strength of vinegar, produced almost immediate death. Air killed immediately. We should therefore be very careful in making experiments, when we inject substances into the veins, that air does not enter with the substances, and cause the death which we impute to the latter.* The Abbe Fontana committed many errors in this way : in short, before any man pretends to determine what will kill, he ought to have killed at least a thousand animals. A poor devil t was lately hanged at Warwick upon no other testimony than that of physical men whose first experiments were made on this occasion. Experiment 20. I threw into the veins of a bitch half gone with pup a quantity of serum, taken from the blister of a person who was ill of a putrid fever, and soon after died. It made her instantaneously sick, and she vomited. She soon miscarried, but in two or three days recovered perfectly. From all these experiments we may, I think, at least draw, as a probable conclusion, that extraneous matters taken into the constitution do not produce any specific or permanent disease, that they # [Air in small quantities, introduced at once, or even in large quantities gradually admitted, is not generally fatal. See Treatise on the Bl°°<^;J , t [Captain Donellan. For an account of this transaction, and of Hunter s evidence on the trial, see Life, and the Appendix to the Lite.] 136 HUNTER'S PRINCIPLES OF SURGERY. operate as direct stimuli, producing immediate effects, and that when these are violent they arise from too great a quantity of the stimulating or irritating substance being thrown in. Poisons come nearest to the idea of humours, but still are not what is meant by humours, nor have ever had this term applied to them. Natural poisons will act somewhat as the substances used in the foregoing experiments did, that is, either stimulate the whole, or part, to increased natural action; or irritate the whole, or part, into some unnatural action, but which will last no longer than the poison is present. The sting of a bee affecting some more than others demonstrates that there is a greater susceptibility in some for such actions than in others, and that it cannot be imputed to humours in the blood, unless we could suppose a humour similar to the poison of a bee, which then might act without that cause. I suppose that bugs bite everybody, but some they do not affect and others they do. This is not so readily demonstrable in the poisons that enter the constitution, though even they cannot be said to be assisted by any humours in the blood. Other poisons, which we call morbid, produce a specific disease similar to the original; but all this does not come up to the idea of humours. A humour is something which is supposed to go on teazing the constitution if not extracted, and is even supposed to be capable of leaving one part and going to another. -■„ What comes nearest this idea of a humour, but only so in its effects, is a surfeit; yet though its effects may resemble those which are entertained of humours, we know from the mode of their origin that they are not caused by a humour. It is a mode of action taking place in the skin from a stimulus or irritation being applied to the stomach. Drinking cold water when a person is hot will produce it. In a similar case, I have seen inflammation come on in the heart and lungs; but they being less able to bear the action than the skin, it proved fatal. The method of cure of those diseases supposed to arise from humours gives us no idea of the disease having arisen from extraneous matter in the blood-vessels. Can we form any idea how bark should extract humours, when it rather stops all evacuations? And yet it cures many diseases. Would bathing in the sea cure those eruptions of the skin which are supposed to arise from humours if they were really caused by them 1 Can we suppose that electricity extracts any humours, when it cures an ague 1 It is not easy to account for the blood having been supposed to be the cause of disease, excepting from it appearing in a bad state after bleeding, and this is always a secondary symptom. Sometimes, when this diseased state has not been very great, medicines have been given to sweeten the blood.*

* [In connexion with this subject, it may not be uninteresting to mention the following facts, which prove that the blood is capable of being greatly vitiated, OF LOCAL AND CONSTITUTIONAL DISEASES. On Hereditary Diseases.—Hereditary, in the animal economy, is applied to properties or peculiarities communicated from the parent to the child. This principle, according to the common notions, may be divided

either by the actions of the body or by foreign substances being introduced into it. An animal body may be divided into those parts which form and those which consume the blood. The former consist of those orgaus which minister to digestion, sanguification, &c. ; the latter, of those structures which perform the offices of nutrition. Increased action also (although perhaps always attended with increased nutrition,) rapidly induces an alteration in the qualities of the blood, and renders a more frequent renewal of it necessary. Whatever, therefore, influences the regularity of those processes upon which the formation and consumption of the blood depend, so as to destroy their just balance, must necessarily influence the constitution of this fluid. The following observations, drawn from disease, serve to confirm this view of the subject. In the first place, then, the varieties in the aspect and sensible qualities of the blood prove that the condition of this fluid varies remarkably under different cirr cumstances, being either buffy, firm, soft, diffluent, tarlike, or wholly incoagulable. It is of various colours and odours ; it requires different times for its coagulation ; it putrefies sooner or later in one case than it does in another ; and the relative proportion of its constituents is very different in different cases. There are, however, other changes to which this fluid is subject which are not equally obvious to the senses, but which are rendered evident by their effects on the body or by chemical investigation. Thus, urea has been detected in the blood in cholera, in certain cases of dropsy in which the urine is albuminous, in considerable abundance in cases of suppression of urine, and in dogs in which the ureters have been tied or the kidneys extirpated ; sugar in cases of diabetes ; and cerebriform, and melanoid matters in persons suffering from these diseases. The injection of putrid or ill-conditioned pus into the blood is found to give rise to a train of symptoms resembling those which are produced by inflammation of the veins, so as to render it highly probable that pus is taken into the blood in the latter cases; but as this is an important point, I shall offer the following considerations in proof of the fact. 1st, Pus is frequently formed in the cavities of inflamed veins and lymphatics at the same time that these vessels are perfectly open towards the heart. 2d, Pus is frequently found in the lacteals in ulceration of the intestines. 3d, Large abscesses are sometimes observed to disappear suddenly, which could not happen except the pus were taken up by the absorbents and carried into the circulation. 4th, In inflamed veins, small-pox, and secondary inflammations, there is reason for believing that pus is taken up and deposited in distant organs, as if by metastasis. 5th, Immediate relief of the constitutional symptoms ensues when ill-conditioned abscesses are laid open. 6th, M. Gendnn has observed a mucous sediment (couche muqueuse) in two cases at the bottom of the vessel containing serum, in the first of which the patient was affected with empyema, and in the second with a large abscess of the thigh. 7th, MM. Duploy, Andral and Rostan have noticed other cases in which the blood, throughout the whole venous system, appeared to have undergone spontaneous purulent decomposition, to which head may also be referred those cases of polypoid concretions in the vessels in which a purulent fluid is found in the centre, generally occurring at the same time with suppurative inflammation in some other part of the system. 8th, The physiological fact, that the actions of absorption and deposition antagonize each other, and are continually taking place in all the shut sacs of the body, which is proved by the rapid disappearance of injected matters. - M. Lecanu has detected the colouring-matter of the bile in the blood £cases,Qt. jaundice, which is well known to tinge the structures and secretions of the body of a vellow colour, and to give rise to drowsiness and other symptoms, ivi. An- 3 12* 138 HUNTER'S PRINCIPLES OF SURGERY. into two kinds: the transmission of natural properties, and the transmission of diseased, or what I shall call acquired or accidental properties. The last is not hereditary in all its causes, for it always requires an immediate cause before the action will take place;

dral has referred to cases in which the principles of the bile were found to be accumulated in the form of depositions in several organs of the body. Many cases are related of vicarious discharges, especially of the urine, and menstrual discharge, when the organs which afford these secretions have been obstructed. In cases of obstructed lactation, M. Dance observed symptoms referrible to the absorption of the milk, of which sort is a case described by Professor Graaf, in which a substance exactly resembling caseum was found in the fluid of an ascites, brought on by suppressed lactation, although in a subsequent tapping six weeks afterwards no caseum was discoverable. Milky serum, depending on the presence of oleaginous matters, apparently diffused through it in the form of an emulsion, is not uncommon, while Blumenbach considers it as not improbable that the ferocity of animals during the rut, as well as man's superior courage, greatly depend upon the reabsorption of secreted semen into the circulation. Besides these instances, there are others of a still more obscure nature, which have chiefly been insisted on by the humourists. Gout and rheumatism, for example, used generally to be referred to a vitiated condition of the blood; an opinion which is certainly favoured by the constitutional and, above all, the metastatic nature of these diseases. In the former there is a disposition to secrete uric acid in superabundance, both in the urine and in the neighbourhood of the joints; a highly azotized principle, corresponding to the highly azotized nutriment which is known to predispose to the arthritic diathesis. In the latter the cutaneous discharges are ktiown to manifest a peculiar acidity. The formation of calculi, the tendency to ossific depositions, and the disease called scurvy appear to depend upon the superabundance of particular salts in the blood. Duhamel has related cases of the most violent effects, followed by gangrene and death, depending upon inoculation with the blood of overdriven animals or of persons labouring under putrid forms of fever. M. Gendrin inoculated a cat, and on another occasion a dog, with the blood of a patient labouring under a putrid fever with eruption of gangrenous pustules, both of these animals soon after dying with analogous symptoms. Dupuy and Leuret have recorded many similar instances in regard to the horse. The following case was related to me by Professoi Coleman, and is an interesting proof of the manner in which disease may be communicated through the medium of the blood. One of his pupils having accidentally inoculated himself whilst dissecting a glandered horse, was taken ill, with a set of anomalous symptoms, for which he was bled. The blood which was drawn was injected into the veins of a healthy ass, and produced the same disease in it as in the horse, notwithstanding that every precaution was used to obviate the possibility of any source of error. Mr. Hunter has related a case in which a child was born with the variolous eruption, and I have myself known a case in which a woman had seven children in succession (six of whom died) "affected with venereal blotches on the nates a few weeks after birth, although she herself had been married upwards often years, and during that period had never been affected with any syphilitic symptom, although she admitted that she had had the disease previously. These and similar facts incontestibly prove that the blood is capable of being vitiated by the actions of the economy, in consequence of which it is rendered capable of propagating disease to others as well as of perpetuating it in regard to its own self. The following are some further instances calculated to show the influence of the nervous system in producing these effects. Dupuytren found that the change from venous to arterial blood was not effected in the lungs when the eighth pair of nerves was divided ; Dupuy, that the fibrin was relatively diminished by the same operation, at the same time that the blood was so much altered in quality as to give rise to dangerous symptoms when injected into the veins of other animals ; Mayer, that the fibrin and haema- OF LOCAL AND CONSTITUTIONAL DISEASES. 139 therefore its cause is not similar to the first. To produce an exact hereditary effect, there must be an hereditary cause or causes; and as in all animals of distinct sexes, in their propagation, there are two causes acting to produce a third, the first and second causes

tosin had a disposition to separate under the same circumstances, and the blood in the whole pulmonary system to coagulate. The coagulation of the blood in mortified limbs, the stagnation of the circulation in inflamed capillaries, the incoagulability of the blood in cases of sudden death, and the spontaneous concretions which sometimes take place in the living veins, are also to be regarded as proofs of the influence of the nervous system. But the blood may be vitiated by extraneous matters. The existence of many of these substances in the blood is inferred from their effects, but we have distinct chemical demonstration of the presence of others. Among the former we may reckon madder, which tinges the bones of a pink colour; the alkalies and acids, which correct the opposite states of the urine; ergot, which produces gangrene; salt provisions, or the long-continued use of the alkaline carbonates, which produce the sea scurvy; mercury, which excites ptyalism ; arsenic, which inflames the stomach; turpentine and asparagus, which communicate their odour, and rhubarb and many other substances their colour, to the urine. Alcoholic liquors pass off by the pulmonary exhalation; garlic and many other substances become sensible by the same means. Carbazotic acid and nitrate of silver dye the tissues, the former of a yellow, the latter of a purple colour. Dr. Graves has noticed a case in which sixty leeches, successively applied to a temale who had lately taken hydrocyanic acid, all immediately perished ; and Dr. Chnstison has related a similar case, occurring six hours after a dose of oxalic acid. Verniere poisoned an animal with nux vomica, and afterwards a second animal with the blood of the first. These examples afford the highest presumption that medicines actually enter the circulation before they produce their effects on the constitution ; a conclusion which is further confirmed by observing that they equally produce their specific effects, whether administered by the mouth, applied to the skin, inhaled by the lungs, or injected into the veins. The following are demonstrative proofs of the correctness of this conclusion : Iodine has been detected in the blood, saliva, sweat, urine, and milk; mercury, in the blood, crassamentum, saliva, and urine; lead, in the liver, spinal cord, and muscles; copper, in the liver and perspiration; camphor, sugar oi lead, sal ammoniac, verdigris, and hydrocyanic acid, in the blood ; sulphur, in the skin, &c. The authorities for these and many similar facts may be seen in Dr. Unnstison's admirable work " On Poisons." That medicines should enter the circulation, and thereby produce their effects upon the constitution, is what we should expect; the extraord.nary effects however, of certain poisonous substances excite our astonishment S:r WilHam Herschel has shown in regard to common matter that a power 50,000 times the power of gravity is generated by alloying mercury with Tn^f°rnJ; The same or greater effects follow the introduction into the^"o^ °f wrtaw »n finitesimal atoms of organic matters. Thus, the Woorara and Ticunas poisons the poisons received in dissection of recently dead bodies; of -hydrophob a svnhilis and small-DOX ; of vipers and other venomous animals, and tnai pro L^ing ffom eTalaKs from tne surface of the earth or fXii^A.we'^S produce effects which, in reference to their causes seem infinite Asweawnot able to point out the distinguishing characters d*™**^^^^^ presented to us in a concentrated state, it cannot be demanded that we .should adduce direct proofs of their existence in the blood *™*™?^W™ sistibly conduct to this conclusion, as we as the ^t that the blood »" ™>J}™ these cases, is altered in its sensible qualities, is ^^JPS^^^SS death, and speedily putrefies after extravasation, ^e following are additio impediments to the discovery of extraneous matters in the blood. 1st, The rapidity with which they pass off by the secretions, 2d, lheir 140 HUNTER'S PRINCIPLES OF SURGERY. ought to be exactly similar in all their dispositions and powers of action, or else the hereditary effect must be a mixture of both, either in equal proportions, or one side may preponderate more than the other. And this we find to be the case. A true and perfect hereditary cause is such as will produce its effects under all circumstances of life, not requiring the influence of any external circumstances whatever. It is hereditary for every animal to produce its own species, which may be reckoned the first hereditary principle. It is hereditary for every animal to produce the proper sexes, whether hermaphrodite or of distinct sexes. Of these distinct hereditary species we have varieties; and if the varieties, whether original or accidental, are such as can be communicated to the young, they are then hereditary qualities. Of this kind we may reckon shape, both of the whole body or of parts, the varieties of which come nearest to the original hereditary principle of shape. Size is a similar principle, as we see it is common for tall or short persons to have children of their own stature. Colour is another of these varieties, for we find this may become part of the principle of propagation, though not so permanent as some others. This property belongs to the epidermis, with all its appendages, as hair, nails, &c, which is subject to greater varieties perhaps than any other part: and those hereditary susceptibilities for certain dispositions and actions of the mind are perhaps as much hereditary as any other property in an animal. These are what we may call permanent hereditary principles, becoming part of the constitution, and as subject to be produced in the offspring as any effect in nature. They are such as will take place under every external influence, as season, climate, &c. It is from these varieties being hereditary that we have a continuance of them from parent to child. When both parents

sion through 15 or 20 lbs. of blood ; 3d, Their disposition to locate themselves in particular organs ; and, 4th, Their actual chemical union with the elements of the blood. Mr. Hunter indeed doubted of the possibility of this latter circumstance taking place; but, not to mention the presumption which arises from other circumstances, the following experiment by Dr. Christison puts the matter beyond doubt. He injected eight grains and a half of oxalic acid into the veins of a dog, which was sufficient to kill the animal in 30 seconds ; but although the blood was immediately tested after death, no traces of the oxalic acid could be disco- . vered. \ Whatever may be thought of these facts as proofs of the humoral doctrines, they plainly establish the fact that the blood is capable of considerable vitiations. » In general, I believe, these vitiations ought to be regarded as effects, and not as * causes, of disease. I conceive, however, in many cases the real cause of disease **■ primarily exists in the blood, and is in that sense truly constitutional; and although we should regard these vitiations of the blood in other cases as merely ., secondary effects, yet we must admit that they will react on the original disease, and in this point of view be well deserving of the consideration of the practitioner. It is not unreasonable to expect that modern chemistry will throw considerable light on this subject, and discover some general principle by which the scattered facts which now exist relating to the blood will be connected and explained. In the present actual state of science these facts are practically useless.] OF LOCAL AND CONSTITUTIONAL DISEASES. are constitutionally alike, they will produce children like one another, and also like themselves, though this is not absolutely certain, for a less marked hereditary principle may arise so as to produce children very unlike the parents. But if the disposition to produce similarity in the children to the parents be different in the two parents, it is impossible to say what the produce may be like. Hereditary varieties will often last for some generations, and then become extinct, seeming, as it were, worn out. A large nose shall be continued in a family for several generations, and then cease. A peculiar gait, the turning in of one or both feet, shall in the same way continue hereditary for some generations; and it is very possible that if such children were to intermarry with one another, the hereditary disposition would never be lost. There are latent hereditary dispositions, which pass over one or two generations, and start up again in the second or third. Children are generally more like one another than like either parent, because they have the united principles of the parents, which are dissimilar, but united will produce the same results. Parents may not be at all times disposed to form children alike. This difference seems to be owing in some degree to time between the births of the children; for we may observe that twins are more like each other than like those born a year or two apart, and these latter more alike than those born at the distance of several years. If the varieties, as white, black, &c, are not original, they must be monstrosities; and then we may say that the disposition to produce monsters continues and becomes hereditary. The white negress, who may be called a monster of the black variety, being supposed to be born of black parents, and being herself white, with woolly hair, is a remarkable instance of the different dispositions of parents at different times. This woman married to a white man, and had three children, one quite black and the others tawny. A gentleman had two children, both born with a disposition to exostosis; the son showed it earliest, and had exostosis on each thigh-bone, and indeed an increase of every bone in his body. The girl was little better off. Neither of the parents had any disease of the kind, but gave the disposition to their children by joint operations. . . Of the acquired Hereditary Principle.—In these cases the-principle is such as to require accident, or some external cause, to produce the disposition in such as have the susceptibility. In this case the susceptibility only is hereditary; but the disposition and action require the application of external influence before they will appear, and are therefore accidental. The action in this case is generally some disease. As the susceptibility is in some degree hereditary, the immediate cause has been in some degree overlooked, and the disease has been called an hereditary disease; but it is impossible for a disease to be hereditary when one of its causes cannot be hereditary. It 142 HUNTER'S PRINCIPLES OF SURGERY. may be hereditary for a man to be irritable, one man'may be more readily put in a passion than another, but no man goes spontaneously into a passion, there must be some violence committed on the mind; and so various are our minds, that some shall be put into a violent passion at a circumstance which would only slightly or perhaps not at all, excite another. The natural susceptibility for diseased action is so strong in some as to require only a slight secondary cause to put it into action; in others so weak, that it requires great violence as an immediate cause to bring on the effects. All hereditary dispositions must be more prominent than those that are acquired or accidental; therefore people who have an hereditary susceptibility for any diseased mode of action will in general have it constantly, at least it will not vary so much as some others. It will not be of that kind which has a great tendency to disease at one time and not at another; such fluctuating dispositions cannot be hereditary. Scrofula is one of those diseases which is supposed to be hereditary; but it is only the readiness to fall into this peculiar action, when properly irritated, that is hereditary: and when such a cause does not exist we find no scrofula. Gout is another disease which is supposed to be hereditary, and there is often great reason in appearance for supposing that it is so. This is a diseased action which perhaps every one is susceptible of; but some fall into it much more readily than others, and this readiness may be hereditary. But this readiness never takes on action of itself; it must have the immediate cause to excite it, which is a stimulus of a particular kind. We find gout attacking people whose parents for many generations have not had it, and often never. We see it starting up in countries where luxury is introduced, where it was never known before. However, there are many instances where it would appear to be hereditary, as in the case of young men of fifteen, the sons of gouty men. But I suspect that this does not arise simply from the father's having had the gout, but from the circumstance that most people who have had the gout severely have deserved it, and that children have inherited the disposition for the way of living as well as the susceptibility for the disease, and will therefore be more liable to fall into the disease than children at large. On this principle of the hereditary nature of diseases, if it be just, every disease under the sun will be hereditary: but many diseases having a stronger visible cause has made the hereditary susceptibility in them to be overlooked. Thus, the small-pox is as much hereditary as scrofula or gout, but from its arising in all cases from poison communicated, and evidently not in a spontaneous manner, is the reason why the hereditary susceptibility has been overlooked. But on our principle the small-pox is as hereditary as any other, only requiring the immediate cause to act to produce it as in any other disease. We may make the same OF LOCAL AND CONSTITUTIONAL DISEASES. observation with regard to the venereal disease, for we see some persons much more susceptible of this disease than others are, and suffering more severely from it when they get it. I do not know that we have an instance of observation which proves that the circumstance of a person's having had the disease renders him more liable to communicate that susceptibility to his offspring than if he had only the susceptibility for the disease, without the action having taken place. If it was a fact that the parents having simply had the disease, in some degree entitled their offspring to it, the human species wrould soon become extinct in those places where such diseases arose: and if the parents having had the disease increased the susceptibility in the offspring, both small-pox and lues would have become incurable by this time. So that the immediate cause, whatever this may have been, does not in consequence of its having had its full effect either give or even add to the disposition for such action. The only difficulty I find, in stating this as a universal doctrine, is in the case of madness. This is allowed to be hereditary, and is I believe as much so as many, yet I cannot find the immediate cause in many cases. It would appear that the disposition to produce action is so strong as to go into action without the application of an exciting cause. It would be worth while to see whether people in a state of nature ever go mad: if they do not, then the state of mind in the civilized state is the immediate cause. A gentleman informed me that he had paid particular attention to the diseases of Indians, and that he never heard of an Indian going mad. On the Effects of Mind on Diseases.—When on the animal economy, I observed that the mind was formed by the senses, as also the will; that the will produced the voluntary actions, but that the mind produced actions both of the voluntary and involuntary parts, which actions are often very irregular and undetermined. On the state of the mind, therefore, the latter will depend, or at least they will change with it, and even the former may be affected by it; indeed there is not a natural action in the body, whether involuntary or voluntary, that may not be influenced by the peculiar state of the mind at the time, and every particular mode of the mind has some parts that are more readily influenced by it than others. The skin is affected by the feeling of shame ; the secretion or even the nonsecretion of the testicles takes place under certain states of the mind. Palpitations of the heart and quick respirations are brought on by some states; purging and increased secretions of the urine by

} In voluntary parts we can also perceive the influence of the mind. It often produces actions independently of the will, especially when these actions are begun by the will, and when the mind is affected by a recollection of them; or even contrary to the will. Thus, tear produces a vibratory contraction of all the voluntary muscles, while the will is doing all it can to stop it. Since the mind has sucn 144 HUNTER'S PRINCIPLES OF SURGERY. power over the natural actions of the body, we might suppose it would have considerable effect in disease ; and this we actually find it has, especially in those who have a strong susceptibility for such actions as the mind can most easily affect. We should naturally expect that it would be [diseases principally connected with the nerves that the mind would most affect, though we do find that there are other diseases, with which they appear to have little connexion, that are much affected by the state of the mind; and I believe that it is principally those diseases in which the alteration is in the action of parts, not in their structure. Minds which are particularly irritable are most subject to such diseases, having the acting parts more under the control of the mind, and less under that of the will; also the involuntary powers are more under the influence of the state of mind, as the heart, &c. These diseases are called nervous, and more peculiarly belong to women, who being less acquainted with the real properties of natural things, are more apt to imagine preternatural ones; and their reasoning powers not being so strong, they indulge the actions of the mind more, and allow it to take possession of the body; for the mind can often prevent diseases of such a nature as are contrary to health, and depend on voluntary actions, of which take the following instance. A woman, aged forty-six, of a good-natured disposition, had been troubled for some years with a drawing of the neck to one side, by the contraction of one of the mastoid muscles : this it was always in her power to prevent, by contracting the opposite muscle, when she sufficiently recollected herself. The right muscle, the one affected, did not contract of itself, unless by some accident she of her own accord contracted it a little, after which it continued contracting till it produced its full effect. When her mind was agreeably engaged she seldom felt it, or when conversing with an intimate friend or reading; but fear and every other unpleasant state always produced it. If she expected to see any stranger before whom she was particularly anxious to hide her defect, she had it always more violently than usual. This circumstance of the mind's continuing action when it has once taken it up, is remarkable in hiccup, which is often produced by laughing; thus hiccuping, which is an involuntary action, is produced by laughing, which is a voluntary one. But as the state of the mind is thus capable of producing a disease, another state of it may effect a cure: so the hiccup may be cured by producing fear. There are other diseases which a state of the mind may cure, though they have not been brought on by it, as agues have been cured by charms which have been used with a thorough conviction of their being a sovereign remedy. I am apt to suppose that a spider's web, when taken for an ague, cures in the same way, at least in one case; for on giving it without the patient's knowledge, it had not the slightest effect; but by persuading the patient that it was a spider, the effect was produced, at least the disease did not return. Even tumours have yielded to the stroke of a dead man's hand. OF LOCAL AND CONSTITUTIONAL DISEASES. It often happens that there is a suspension of some actions in an animal body, and those actions return again. Thus we have epilepsy, which is a suspension of the sensitive principle's actions: sometimes we have suspension of the heart's actions. It is perhaps impossible to know the cause of these suspensions, and equally so the cause of their return. I am apt to suspect that suspension of natural action becomes the stimulus to the powers to put themselves in action again; or, in other words, the suspension becomes by its continuance a force imposed on parts to act, and they act to relieve themselves. Thus, by stopping respiration we have such a stimulus raised in consequence that we can no longer live without the action, and the action takes place. I suspect that opium often produces a struggle between the necessity of action and the consciousness of the preternatural suspension, which rather rouses. Death, which is the ultimate suspension of all actions, seems to explain that, as a person seldom dies without a struggle or convulsion. Convulsion appears to me to be an action arising from a consciousness of debility ; as if there was an endeavour to act to preserve life, but not being able to preserve it, they give up the contest. Of Symptoms.—A symptom is a sensible effect of a diseased action. The first mode of sensation is when the disease is shown directly, without the medium of any other reference, and is known only to the patient; of this kind is pain. The second is where it is given by a reference to some other sense, as that of touch, smell, &c, and is common to the patient and others; of this kind is the swelling of tumours, the redness of inflammation, &c. The third arises from a deficiency of sensation, and can be known only to the patient himself. It is by description and the second set of symptoms that the practitioner receives his information. Local disease may produce only the first mode of intelligence, as pain; or it may proceed to the second, as inflammation ; or the second may be produced without the first, as indolent tumour, not known till felt by the hand. Pain is a simple sensation which is common to many diseases-, and is divided into several kinds, as sharp, sore, numbing, heavy, &c. The sharp pain is that produced by cutting with a knife ; the sore, from inflammation and ulcers ; the heavy, that which takes place in rheumatism ; the numbing, from pressure on a nerve. The sharp and sore depend on what I shall call vibration of pain, particularly the latter. The heavy seems to be a continual pain, or where the repetitions are so quick as to appear continued ; but probably all of them are owing to a succession of actions of the nerves. We refer all the sensations we can to those senses which give us the greatest intelligence. We call them sharp pains from their giving the sensations of any thing that biles, or stings, as bees, or acids on the tongue; heavy, from their giving us the sensation of bearing a weight on the part. A gentleman who had a hemiplegia, said his sensation 146 HUNTER'S PRINCIPLES OF SURGERY. was similar to an acid on the part, that is, to that feeling on tho tongue. We have often a bad taste in the mouth, or a bad smell; this is not always a sign that the saliva or mucus is altered in its qualities, as it is in salivation from mercury, which appears to be from the taste and smell of the mercury, but it is sometimes produced by a morbid action of the nerves. We have these symptoms, together with ringing in the ears, commonly in the beginning of diseases, and probably they arise from the actions of the disease in the nerves of the part. Neither susceptibility nor disposition for diseased action can produce a symptom; it must be preceded by action; though I believe that there will sometimes be an unnatural feel in a part before action has taken place, as before a fit of the gout attacking the foot an indescribable sensation is sometimes felt, and when the action takes place the constitution is relieved. Symptoms are either local or universal. Local, as chancre, cancer, &c.; universal, when they accompany universal diseases, as fever. Local symptoms may produce universal ones, which is a means either of increasing the local symptoms or of curing the disease. Local symptoms will vary according to the nature of the disease; its violence or its situation, as inflammation, will produce different sensations in different parts. Universal diseases will produce some of the following symptoms: affection of the pulse, which arises from the heart's sympathizing and partaking of the disease; the alterations are very various, as full, strong, weak, small, &c. The secretions are altered, as in fever; the tongue becomes covered with its own secretion, at first white, afterwards brown, or some* times black, which last colour arises from blood being mixed with the secretion. The tongue also contracts in size, and we have often thirst without its being dry, and sometimes, as in low fevers, very dry without thirst, which last is owing to a diminution of sensation in the nerves, and is an unfavourable symptom. The urine is highcoloured, without sediment, owing to its being retained long in the bladder, from debility of that organ or from blood being mixed with it. The respiration fails, from debility in the lungs. The heat of the skin is altered from too great or too little action of the vessels. The colour of the skin in some diseases changes, as from white to yellow in a very short space of time, not from jaundice, the white of the eye not being changed; nor could jaundice be so quick in coming and disappearing; it is probably a change in the rete mucosum of the skin, such as takes place in the chameleon and some other lizards; veins of the skin are enlarged by any tumour seated beneath them ; as in hydrocephalus, tumours of the breast or of the uterus during gestation, the veins of the head, chest, or belly will be found enlarged. The feeling of the part is the first mode of intelligence. Suppose a stone in the kidney; it may produce three symptoms : 1st, Pain in the part; 2d, Vomiting, which is symptomatic ; 3d, Bloody OF LOCAL AND CONSTITUTIONAL DISEASES. 147 urine. Now these symptoms may occur in other diseases, independently of stone ; if they are combined, they afford a pretty certain diagnosis of the presence of stone, but any one or two of them leaves it doubtful. These symptoms attend the passing of a stone through the ureter, as well as when in the kidney ; and when a stone gets from the ureter into the bladder the symptoms abate, and a different pain is felt, and this change occurring confirms us in the opinion we had before formed of the existence of a stone. Anomalous Symptoms.—These are not immediately expressive of the disease, but make the diagnosis doubtful. They are very numerous, taking in all the symptoms which occur from dentition, worms, &c. Many of them are from sympathy, which we mentioned before. Delusive Symptoms respecting Sensation.—This delusion of the senses makes disease seem where it really is not, from the different seat of the symptoms and of the diseased part. Thus, diseases of the liver are referred to the shoulder, of the testicles to the back, of the hip to the knee, and even in some cases, as was before observed, they are referred to some other person. When the trunk of the nerve is injured, the pain is referred to the termination of it, as, after amputation of the leg, pain is felt in the toes. When pressure is made on a large nerve, the most acute sensation will be at some distance below the part pressed on. A gentleman complained of a pain in the hip, running down the outside of the leg and foot. Supposing it rheumatism I gave him James's powder, Dover's powder, and volatile tincture of guaiacum, but with no good effect. A liniment of opium to the leg and foot gave some relief. He at last perceived a tumour by the os ischii, just at the posterior edge of the gluteus maximus. This tumour increased, and the person died. The tumour was found to fill a part of the pelvis, and had made its external appearance at the foramen magnum ischii, being filled with coagulated blood ; but the pain in the limb seemed to have been produced by its pressing on a great branch of the nerve, but chiefly perhaps from the great ischiatic nerve being stretched very tight over the upper surface of the tumour. Here that happened which may often be observed; that is, the impression made on the trunk of the nerve gave a sensation as if it had been on the extremities of the nerve. The first action of a nerve is at its extremity, and the last in the brain; and this last in the brain refers the sensation receiving the first impression ; and if, after the brain has become accustomed to refer any sensation to the extremities of the nerves, any impression be made on the trunk, the brain receives the impression in the same point where it was accustomed to receive the impressions made on the extremity of that nerve, and therefore the mind refers the sensation to the same spot, that is, the extremity of the nerve. This happens when the part to which the sensation is referred does not exist, as 148 HUNTER'S PRINCIPLES OF SURGERY. a person, having had an amputated limb, will for a long time refer his sensations to the fingers or toes. In diseases the general character of the patient should be known, which is essentially necessary before we can judge of every symptom ; for besides what we can know by the symptoms of a disease, yet peculiarity of temperament, &c, will occasion great differences in the character of the disease. For our being informed by the first mode of intelligence, the patient's sensations, the patient must be in his right senses, otherwise he may be deluded, and delude us. But even where the patient is perfectly sensible, many symptoms may appear to the physician which the patient is not sensible of, as wild looks, quick pulse, &c. The brain may not be conscious of them, and a false conception of their feelings is then present; and this may be called half-delirium. A complete delirium is an action of the mind directed by no sensation whatever. But we do not know how to distinguish between these two deliriums, the former being an action of the mind from sensation, but which sensation is incapable of directing its influence to the senses, and refers it to other parts or other objects. These should be well understood in practice, as in half-delirium the patient will have the sensation, but will direct it to some one else, or to the wrong part, which if we know we may be able to afford them the relief they want. The history of every thing relative to a disease should be known, as symptoms alone are often not enough to direct us; we should, therefore, get the history of it and of prior diseases, of peculiarity of constitution, manner of living, &c. CHAPTER XII.

GENERAL PRINCIPLES OF INFLAMMATION.

Frequency of inflammation;—nature of;—enlargement of vessels ;—several species ;—simple or compound ;—three results from inflammation in a healthy constitution :—adhesion,—suppuration,—ulceration.—Adhesion ;—nature of the uniting medium ;—partakes of the quality of the diseased solids ;—its uses. —Suppuration;—differs in degree accordingto the exciting cause.—Ulceration ; —its uses.—Exciting causes of inflammation ;—accidental or specific.__Remote causes of inflammation.—Comparative susceptibility of parts to inflammation.—Effects of inflammation on the constitution.—Of the pulse;__varies with the states of the constitution ;—varieties of pulse ;—causes of the varieties.—Effects on the constitution according to the state of the inflammation ;__ rigors.—State of the blood in inflammation ; colour, heat, coldness, pain of the inflamed parts.—Declension of inflammation.—Ecchymosis ;__varieties of-__ termination of.

The operation in the body called inflammation is one of the most common and most extensive in its effects, and requires our greatest GENERAL PRINCIPLES OF INFLAMMATION. 149

attention. It is the cause of many effects, both salutary and diseased, producing abscesses, fistulas, diseased bones, &c, and in many diseases is the first step towards a cure; so that it becomes a first principle in surgery. Inflammation would appear to be produced by an increased action of the vessels, but it is most probably in the smallest vessels, for it may be confined almost to a point where none but the smallest vessels exist. What the particular action is, or in what it differs from the common action of vessels, is not easily ascertained, we being more able to judge of the effects than of the immediate cause. Inflammation may be considered as a genus, of which there are many species. It may be divided into healthy and unhealthy. The healthy is that which will always take place in a healthy constitution or part, and is rather to be considered as a restorative process than a disease. Unhealthy inflammation is that which takes place in an unhealthy constitution or part, and will vary according to the kind of unhealthiness of that constitution or part. Inflammation is either simple or compound ; simple, when there is only one mode of action in the part inflamed, as in the first stage; compound, when there are two or more modes of action. The compound produces three great effects, namely, adhesion, suppuration, and ulceration, which I shall call adhesive, suppurative, and ulcerative inflammation. The last is only an effect of inflammation, for the process takes place in a different set of vessels. I shall place the adhesive first in order, though it is not always so, for with respect to priority of these effects of inflammation, it depends principally on the nature of the parts, with the degeee of violence of the inflammation. To explain this more fully, I shall consider inflammation as it affects, 1st, The cellular membrane in general, and the circumscribed cavities; 2d, All the outlets of the body, i. e., the excretory outlets and ducts of glands, as the mouth, nose, tunica conjunctiva, &c, which have been called mucous membranes, and which I shall treat of in their proper order. When inflammation takes place in the first order of parts, it is commonly the adhesive: but it will be according to circumstances whether the suppurative or ulcerative follows first, and probably according to the degree of inflammation. But it sometimes happens that the suppurative takes place almost immediately, probably from two causes, either from the inflammation exciting the suppurative almost immediately after the adhesive, or from the inflammation having little or nothing of the adhesive in it. I suspect that the erysipelatous has little of the adhesive in its nature, no adhesion taking place before suppuration, whilst in phlegmonous inflammation of the cellular membrane it does; so that the erysipelatous might be called oedematous inflammation. When inflammation occurs with violence on the surface of the skin, the ulcerative process takes precedence of the suppurative, although m the cellular membrane the reverse of this is the case. In the second order ot 13* 150 HUNTER'S PRINCIPLES OF SURGERY.

parts the suppurative takes place first, and the adhesive does not take place, unless the inflammation is carried to a great height. When the inflammation is in the first order of parts, the suppuration and ulceration are so many actions superadded to the first, or adhesive, and arising out of the effects produced by that which now become new causes, especially of the ulcerative, which is an action of the absorbents. All these actions arise from the first irritation or cause. The adhesive or suppurative, either in the first or second order of parts with their varieties, may have a fourth character superadded, such, for example, as the scrofulous or venereal disposition, or other specific disease. These three modes of action, when carried on perfectly, are the effects of a good constitution, and constitute what I would be understood to mean by common inflammation. The union of cavities in an animal body is formed by a uniting medium, which appears to be the coagulable lymph, which, by the inflammatory disposition of the vessels, is separated from other parts of the blood and thrown out on these surfaces. That this is the case appears from the following observations. In all large cavities where we can make our observations with certainty, we find when they have been inflamed that a substance similar to the coagulable lymph when separated from the serum and red particles, is diffused all over the sides or through the cavity. When we cut into an inflamed part after death, we find it firm and solid, like the section of a lemon, or some oedematous tumour, where we know extravasation has taken place ; and this appearance arises from the cells of the cellular membrane being loaded with extravasated coagulable lymph. This mode of separation of coagulable lymph is not peculiar to this species of inflammation; it is separated on many other occasions to form tumours,* where inflammation does not seem to be the leading cause. It is probable that the coagulable lymph undergoes some change in its passage through the inflamed vessels which obliges it to

* [As we are not acquainted with the mode in which the process of nutrition is accomplished in its natural state, it is not to be expected that we should be able to account for those aberrations from the healthy state which constitute tumours,. If the formation of tumours depended upon the organization of effused blood or lymph, we should expect to see them much more frequently than we do, since few persons escape effusions at one time or other; and we should likewise expect to see them differ in their incipient and in their advanced stages. Observation, however, discloses nothing of this kind; on the contrary, the peculiar structure of tumours is as well characterized at first as when they become more fully developed : the blood or lymph which is effused in inflammation or by accident is generally absorbed, and in the great majority of tumours we are unable to refer to any previous injury or inflammation to account for their orio-jn. See Home {Trans, of a Soc. for the Imp. of Med. and Chir. Knowledge, vol. i.,) and Abernethy {Works, vol. ii.), who have advocated the opinion in the text, and Lawrence {Med.-Chir. Trans., vol. xvii.), who justly, in my opinion, objects to the statements of these gentlemen.] GENERAL PRINCIPLES OF INFLAMMATION. 151 coagulate sooner than it otherwise would, for in those cases of inflamed arms, after bleeding, we find that the cavities of the veins are in many places furred over, and in others united by coagulable lymph, which must have been thrown out by the vasa vasorum, and coagulated blood immediately. Hence it is reasonable to suppose that in this separation the lymph must have undergone some change, arising from the vessels, and that it is not simply such coagulable lymph as is circulating in the blood, else it would be carried off by the circulating blood passing through the vein. This change I suppose to arise from sympathy with the inflamed vein. The lymph seems, however, to retain the living principle, and probably in a greater degree than under common circumstances, and is, therefore, better fitted to become a living solid. It does not seem, however, absolutely necessary that coagulable lymph should first undergo this change in the extravasating vessels, for, as I have before said, blood extra vasated from ruptured vessels is perhaps equally efficacious in this respect.* It does not seem necessary for both surfaces that are to be united, to be in a state of inflammation, but only for one, to throw out the coagulable lymph; nor indeed does inflammation of either seem necessary, for union by extravasated blood may take place without inflammation. Extravasated coagulable lymph, which produces either adhesion or tumours, alwTays partakes of the nature of the diseased solids that produced it; if the case is venereal, the new substance is of the same nature; if cancerous, cancerous ; for the absorption of this effusion from a cancerous breast will produce cancerous axillary glands. The intention of the adhesive inflammation is in some degree to set bounds to or prevent the necessity of its own larger extent. In large cavities the inflamed parts adhere, and thereby exclude or prevent the other parts from the necessity of falling into the same irritation. But the chief intention is to confine the suppuration to those parts where it takes place, for where the adhesions are perfectly formed the operations of inflammation appear to be completed, so that the suppurative process does not spread; it also serves to confine the matter to the cavities where it is formed. Inflammation often goes no further than adhesion, and then subsides and goes off, which is termed resolution. This cannot take place in all inflammations, but only in those where the parts can be brought into contact, for if the part in which it takes place is an open cavity, suppuration will take place. When the adhesive inflammation is not capable of resolution, suppuration takes place. The immediate effect of this process is the production of matter from the inflamed surface, which appears under such circumstances to be a leading step to the formation of a new substance, called granulations, which granulations are the

* [See note, p. 34, and Treatise on Inflammation, Part II. Chap. I.] 152 HUNTER'S PRINCIPLES OF SURGERY.

second method of restoring the first order of parts to health. But on all internal canals suppuration does not necessarily lead to granulation. In order for spontaneous inflammations to produce suppuration, they must be much more violent than those inflammations (suppuration being equally necessary), arising in consequence of an operation or accident: and those inflammations from either operations or accidents, if they have not produced death in the part operated on, are more violent and of greater extent than those in which death of a part has been produced. Thus, the inflammation of a boil or bubo is more violent and commonly more extensive, than that in consequence of a cut, or even amputation of the leg ; and the inflammation arising from these latter will be more violent than that from a gunshot wound on the application of caustic. It may not be easy to account for all these differences; howrever, it is possible that in spontaneous inflammations the inflammation is more necessary for the ultimate effect than the suppuration; as in gout, the inflammation is the mode of carrying off the action of the disease. It is curious to remark, that in gout nature seems to produce all the purposes and effects intended by inflammation, but unaccompanied by either adhesion, suppuration, or ulceration; and although the inflammations runs much higher here than in many other cases, and although it is attended with all the common appearances, yet no adhesions are formed here: for the lymph is taken up, and chalk (urate of soda) is deposited in its place. In spontaneous inflammation, parts are either naturally more susceptible of the inflammation, or become so by disease. When inflammation is produced by stimulus of the death of a part, or of effused blood, the inflammation is commonly slow ; but that from a bruise is often quick and violent, but then the injury has not produced death. If caustics do not act with vigour, they will irritate and inflame much sooner than if they had immediately killed the part; but irritating applications must be continued some time to produce inflammation. After operations where inflammation must take place for the union of the wounds, suppuration is more necessary than inflammation, and we find it is soon produced. The ulcerative inflammation is that which takes place in consequence of suppuration, therefore is not so much the original inflammation as the consequence. It is that inflammation which disposes parts to absorb themselves, and which brings matter or any extraneous substance to the surface to be discharged, the absorbents removing all the parts lying between the matter and the surface. This process has been erroneously ascribed to the melting down or dissolution of living solids with the pus. From the foregoing general account of inflammation, it maybe said to arise in all cases from injury done to the solids, where either the natural conformation of parts on which natural actions depend is so destroyed that they are not able to support themselves in that state, or from the natural actions or functions of a part being materially GENERAL PRINCIPLES OF INFLAMMATION. obstructed, the texture not being primarily affected. The first state arises from causes that are visible or external, such as the application of any irritating matter, as a blister, heat, or even cold, which acts as a sedative when applied only in a certain quantity ; but when in too great a quantity, the parts, finding that they are losing their action, are roused to action beyond that which is natural, in order to destroy the irritating cause. Inflammation may also be produced by causes not known or suspected, or from a constitutional disposition being determined to some part, producing local effects. I need hardly mention that fever is thus often a cause of local inflammation. Inflammations from the constitution are of two kinds : one may be called accidental, as those arising in common fever; the other are determinate, depending on the species of fever which may be called specific, as small-pox, &c. These inflammations are thought to be critical, but I very much doubt the truth of this opinion. The small-pox and chicken-pox are the only diseases that can be brought in proof of it, with perhaps the inflammation of measles; but even these pustules or abscesses are, perhaps, not necessary, as critical abscesses, to carry off the fever, for specific fevers cannot exist beyond a certain time, though no eruption appears; which time depends on the nature of the poison, and the constitution. And in these diseases we have large abscesses as often formed as after any other; and certainly I cannot suppose those abscesses to be critical, for they possess nothing of the specific nature of the preceding disease, and must therefore be common ; or, where the constitution possesses a susceptibility for scrofula, they may be scrofulous, but not critical; and as the preceding disease has already been followed by pustules or abscesses which, if any deserve to be termed so, certainly ought to be termed critical,we shall find that these inflammations and abscesses depend on the state of the constitution and part at that time, and are an effect of simple fever abstracted from every specific peculiarity. Fever is at all times a disturbed action, which may have a specific action joined with it or not. The inflammatory fever is perhaps, the most simple fever; and the putrid fever is, perhaps, only the same fever occurring in a constitution predisposed to its peculiar actions. This opinion may be illustrated by what occurs in the small-pox ; two different people having this fever from the same infection, the effect in one will be benign small-pox, with only simple inflammatory fever ; in the other it will be erysipelatous or confluent small-pox, with a tendency to putridity or gangrene. This difference cannot depend on the specific poison, as this can have but one mode of irritating. Now, since every fever is capable of producing inflammation and abscess, and as I have shown that in specific diseases they have no right to be termed critical, they certainly cannot be supposed critical in common fever. Inflammation may arise from one of four causes, which may be called remote: 1st, From accidental force applied to a part: 2d, From some irritation, which does not destroy the texture of a part, but simply the natural actions, as friction, blisters, heat, cold, and 154 HUNTER'S PRINCIPLES OF SURGERY.

often fevers of various kinds ; 3d, From some particular disposition in the part itself, as boils arising spontaneously; 4th, From the general state of the constitution affecting some particular part, as gout falling on the toe, or the irritation of fever on the lungs, liver, or any other part, producing adhesions or abscesses; but such, I suspect, are of the scrofulous kind, and not in the least critical, and therefore belonging to the second cause. To these, I think, we may add specific causes, as scrofulous, venereal, &c, as a 5th; and the stimulus of defect or imperfection of parts, especially cavities, as a 6th. Obstruction of the blood's motion in the small vessels has been long supposed to be a great cause of inflammation, but is, I believe, now pretty generally rejected. This was certainly too confined an idea: it reduced all inflammations to one species. The only distinctions of inflammations must then have arisen from the nature of the constitution; but this doctrine never could account for the peculiar action of any specific disease or poison. It was also too mechanical. If they had said that any obstruction to the natural actions of the parts which could stop the blood's motion in the part became the cause of inflammation, they would not have been so much out as to a possible cause of inflammation. In such a case the stagnated blood would cause irritation of the vessels, and suppuration would be produced to get rid of it. The immediate operation of these inflammations cannot be called disease, though their remote causes may, as small-pox, &c.; for they may arise from the part being only disturbed, and hardly exceeding the idea we have annexed to that of being disturbed. It is the cause producing inflammation, then, which is the disease and not the inflammation,* for all inflammations that can be called diseases have specific causes; and, indeed, even these can be hardly called diseases, for in small-pox, where the inflammation goes on well, it is merely the action of health; if diseased, it would be erysipelatous, &c. Sometimes, by amputating a leg, more than simple disturbed action is produced, for it is a great loss to the constitution ; but yet when the constitution is in a healthy state, we generally find a healthy inflammation and digestion of the wound take place: it will not go into an inflammation which is unhealthy. Specific inflammation as well as simple inflammation partake of the nature of the constitution. Some constitutions are more disposed to certain specific actions than others, and will fall into that specific kind of inflammation, as the erysipelatous, the

* [That is, inflammation with a specific character is the only inflammation which can be denominated disease. The meaning of the author I conceive to be simply that pure inflammation is a restorative action, in contradistinction to the actions of disease which tend to destroy (pp. 15, 97); and to this general statement there can be no objection, although it must be borne in mind that the rule of judging from final causes cannot be applied absolutely without excluding from the list of diseases a great many affections to which it would be absurd to deny this title, such as sickness, purging, increased secretions, ulceration, mortification, &c, the tendency of which on many occasions evidently is salutary, or to get rid of some noxious matters : still there is sufficient ground I think for the general observation.] GENERAL PRINCIPLES OF INFLAMMATION. 155 scrofulous, &c.; and every aggravation is an aggravation of the specific nature of the inflammation; thus it happens in scrofula, cancer, &c. But some specific irritations bring all constitutions, to their own nature, as the plague, jail-fever, &c. Here it is not a specific joined with a simple inflammation, but a thorough change of constitution, and the patients generally die, all suffering alike. The inflammation arising from these causes may be either the adhesive or the suppurative. From all which we may conclude that irritations either produce inflammation according to the disposition of the constitution or of their own nature, of which last is the plague. The specific diseases will change, according as the constitution changes; for instance, after receiving the small-pox, if the constitution, then healthy, should by any means become disposed to show putrid symptoms, the small-pox will have the same appearance; but if the constitution is altered from this tendency, the eruption will also alter. Now the knowledge of this fact is very useful in the treatment of specific diseases; for example, if with a venereal chancre the constitution be erysipelatous, we may have an erysipelatous inflammation in addition to the chancre, which will spread over the whole penis. Now, in this case, we must make use of mercury against the one, and of bark against the other of these specific diseases, until we bring it to the simple ulcerative inflammation. Again in the small-pox, when simple, the pustules retain their specific distances, but if an erysipelatous inflammation be joined to it, it becomes of the confluent kind. In the irritable constitution we find from continuous sympathy the inflammation will extend itself very far; but in general we find that considerable inflammations confine themselves very much. Some parts are more susceptible of one kind of inflammation than of others; some admitting only of one kind, some two, and some all three, which difference appears to be according to the situation in the body of the inflamed parts, and also according to the nature of the parts inflamed. The deeper-seated parts, especially the vital, admit very readily of the adhesive inflammation, as is proved by dissections, for we hardly ever open a human subject that has not had considerable adhesions in the circumscribed cavities; but they do not so readily pass into the suppurative, which is fortunate, otherwise internal inflammation would oftener kill. But if the inflammation comes on at once with great violence, it would appear to pass almost at once over the adhesive, and to take up the suppurative action, and in this case we may sometimes have the erysipelatous added. The external parts of the body are more susceptible of the suppurative inflammation than the internal, but they always begin with the adhesive. This greater susceptibility of the superficial parts to suppuration is shown in the passage of pins, bullets, and other extraneous bodies to the surface : if deep-seated, they will remain a long time inactive, inclosed in a cyst, and produce no inconvenience until they work their way to the skin, when siumnm*"* L56 HUNTER'S PRINCIPLES OF SURGERY.

be produced. It is very remarkable of the cattle which feed in the bleaching-fields, and are always found after death to have a number of pins in them. (The stomach of a bull was shown, in which several pins were sticking, and which were not known to have caused any inconvenience.) Perhaps this does not altogether depend on the situation of the part, but also, on the degree of irritating power possessed by the extraneous substance: thus, metals and glass seem to produce such a disposition in the part, that it becomes satisfied with the adhesive inflammation. A gentleman had a piece of glass in his hand for many weeks, which produced no pain, except on pressure. This insensibility of deep-seated parts to extraneous substances, depends on a sac being formed around these substances, possessing a peculiar degree of insensibility. Nature acts here with her usual care, preferring the least evil by securing the extraneous substance in a part possessing peculiar insensibility, rather than calling up the vital powers to produce suppuration, which must be considerable to reach the surface, and might expose parts which would be attended with considerable danger; but when they become external, then she chooses the other, to get rid of them as soon as possible. In my division of parts, as regards inflammation, into two orders, I have made a distinction between the cellular membrane and circumscribed cavities on the one hand, and the ducts, canals, and outlets which are lined with what has been called a mucous membrane on the other. In the first order of parts, inflammation proceeds in this order; adhesive, suppurative, ulcerative ; but in the second order of parts, the order of inflammation seems to be inverted as regards the two first, as may be seen in internal canals. In these, if the inflammation is but slight, the suppurative takes place almost immediately, not being retarded by the adhesive going before ; as we see in gonorrhoea, catarrh, &c. It has been said that these discharges are not purulent, but in my opinion they certainly are; the purulent matter being only a change in the natural secretion, and its thickness or thinness depending on the degree of the inflammation. If the erysipelatous inflammation should come on in these parts, then the movement takes place from the suppurative to the ulcerative. In the mucous membrane ulceration will take place, probably from the violence of the inflammation having produced coagulable lymph, which acts as a stimulus, and the parts having been weakened, are unable to support themselves : this is sometimes the case in the mouth, from salivation ; in the tongue, &c, in scurvy; in the intestines, in dysentery, &c. Mr. Hunter endeavoured to produce adhesive inflammation in the vagina of an ass. He first, by moderate stimulus, could only produce suppuration, but by a very active stimulus, as a solution of corrosive sublimate, he produced the adhesive, causing coagulable lymph to be effused, which afterwards became membranous and inseparable, as was seen in the preparation of the parts which he exhibited. Strength and weakness of the constitution, or of the part affected, GENERAL PRINCIPLES OF INFLAMMATION. 157 will produce very different effects in inflammation. Strength produces good effects, and renders the disease more manageable, for it lessens irritability. Inflammation is most manageable in parts in the following order: muscles, cellular membrane, and skin, and the more so the nearer the source of circulation. In other parts, as bones, cartilages, ligaments, &c, which have but little power in themselves, it is less manageable, though the constitution be good, for the constitution feels conscious of the weakness of these parts, by which affection of the constitution they become further weakened. In vital parts, inflammation also is very unmanageable, though these have power in themselves; but in consequence of their being affected, the universal health is destroyed, and hence the disease is less manageable. If the stomach is inflamed, no operation of the body can go on well, the powers of restoration becoming weaker than ever; hence the greatest danger is to be apprehended. Sti'ength of the constitution and parts affected, when under inflammation, produces the following effects : viz., a more ready and quick termination, whatever it be. Thus, a wound in a healthy constitution unites more readily by the first intention; adhesive inflammation more readily terminates by resolution. If inflammation have got beyond the first stage, it passes sooner on to the suppurative inflammation; nature going through her operations with greater facility and despatch in such a state of constitution. Weakness of the Constitution and Parts.—When a wound is made in a person of a weak habit, the union is more difficult, and the inflammation is more likely to continue; and this not from there being a greater disposition to inflammation, but from want of a power and disposition to heal, nature needing greater and longer exertions to produce the intended effect. In this state of the constitution and parts we often find that parts seem hardly capable of taking on either adhesive or suppurative inflammation : and in some of these habits inflammation will hardly even follow a solution of continuity. As in dropsy, I have observed that the puncture made by tapping or scarifications will hardly heal; a degree of inflammation does take place, but not sufficient to procure a healing of the wounds or suppuration, but mortification soon comes on. If in such a constitution a wound is made, the blood not coagulating sufficiently to heal it by the first intention, dies, and becomes an extraneous substance, causing irritation: suppurative inflammation succeeds, and often mortification, which mostly proves fatal. Effects of Inflammation on the Constitution.—The sympathy of the constitution upon an act of violence to the parts, is probably the most simple act of a constitution. But this will vary in different constitutions, because all constitutions do not sympathize equally. It will vary according to the stage of the inflammation, and according to the disposition of the parts inflamed. We find the effects of inflammation on the constitution as various 14 158 HUNTER'S PRINCIPLES OF SURGERY. as any other circumstances, which appear to arise from the following causes ; first, from the nature of the constitution ; secondly, from the nature of the inflammation, whether common or specific ; if common, according to the stage of the inflammation, whether adhesive, suppurative, or ulcerative ; if specific, according to the kind, although I believe specific irritations do not produce much variety in the constitution, except the plague, which entirely changes it, and such as by their long continuance weaken the constitution, as lues, when Of long standing; but this will be similar to any lasting disease, for at first it certainly does not affect the constitution so as to alter the disposition of a wound made on any part: thirdly, from the nature of the part inflamed, whether vital or otherwise : and, fourthly, from the different situation of similar parts, as of the muscles or cellular membrane in the legs or arms, &c. In inflammation we have seldom more than the continuous or the universal sympathy, but sometimes the remote. The continuous causes the inflammation to spread. The general is when the constitution becomes affected. The remote is seen in pain of the shoulder, from inflammation of the liver. As the effects which inflammation has on the constitution are by sympathy, they will be in proportion to the readiness it has to go into that action; and this is much greater in some constitutions than in others; moreover, every constitution sympathizes more readily with some parts than others. The kind of constitution least affected is generally the most healthy where sympathy hardly takes place, the surrounding parts even seeming hardly to feel what is going on in those nearest them. The nature of the inflammation produces, I believe, but little variation in these effects : for, of whatever kind, the sympathy will be in proportion to the violence of the inflammation, and its rapidity. Hence as the inflammation which produces healthy suppuration is more rapid, it generally produces more violent effects on the constitution than any other. The effects which inflammation has on the vascular system, and which are chiefly discoverable by the pulse, are very remarkable. In considering the peculiarities of the pulse, it is always necessary to remark that there are two powers acting to produce it, viz., the heart and the arteries. That one part of the pulse belongs to the heart, another to the arteries, and a third is a compound of both. The stroke, which is the pulse, (as regards the number of strokes in a given time, the regularity or irregularity as to time, and the quickness of these strokes,) belongs to the heart. The vibratory pulse and slowness of the systole, with the fulness and smallness of the pulse, belong to the arteries. As the pulse arises from the actions of the solids on the machine, it is of course according to the nature of the machine at the time; therefore is capable of being in one of two states, natural or diseased. In most diseases of the constitution, whether original or arising GENERAL PRINCIPLES OF INFLAMMATION. in consequence of diseases of parts in which the constitution becomes affected by sympathy, the pulse is altered from the natural to the diseased state which is according to those affections. The varieties of which the pulse admits are numerous. It may be increased or diminished in the number of strokes: regular or irregular as to time; quick in its stroke, or diastole, and slow in its systole ; or it may be hard in its diastole. In all cases probably, when the constitution is in a state of irritation, the pulse will be quick and frequent in its number of strokes in a given time, and the artery being hard, from the constant contraction of its muscular coats, will give a feeling of hardness to the touch: besides which the diastole of the artery is not uniformly and regularly the same, but there are a vast number of stops or intermissions, which are so quick as to give the feeling of vibration, or what we call thrill. In such a disposition the pulse may be either full or small. These two opposite effects do not seem to arise from the difference in the quantity of blood, as might at first be supposed; but arise, I rather suspect, from the difference in the degree of strength and quantity of irritability that the patient possesses at the time, which when joined, give an antidiastolic disposition to the arteries, so that when the arteries have a full power of contraction and are in a state of irritation at the same time this effect will always take place. It is certain that arteries in such a state of constitution do not dilate so fully and freely as at other times; and as this varies quickly as the state of the constitution varies quickly, it is more reasonable to suppose that the effect is immediately from the arteries than from an increase or decrease in the quantity of blood. If this is really the case, we should naturally suppose that the motion of the blood in the arteries would be increased in proportion to their diminished size, unless we should also suppose that the systole of the heart should be diminished in the same proportion, which I think is probably the case,'as we find the blood forsakes the surface of the body in such a state of constitution, which must therefore be collected in the larger veins about the heart. But if the heart were to throw out its whole contents at each systole, the velocity of the blood in the arteries would be immense, and must be then forced into the small vessels on the surface of the body, which it certainly is not. A quick hard vibratory pulse is generally attendant on inflammation. The fulness or emptiness of the pulse depend greatly on the parts that are affected, which either increase or decrease the irritability. Different Parts produce different states of the Pulse.—In inflammation of common parts, as the skin, cellular membrane, muscles, &c, the pulse will be full and strong, and the symptoms acute, especially if near the heart. Ligaments, cartilages, tendons, and bony parts produce symptoms which are less acute; the pulse is not so full, but quicker, there being in these cases a greater degree of irritability. In the vital parts of the second order, as the brain, the 160 HUNTER'S PRINCIPLES OF SURGERY.

pulse is soft and slow; but in the stomach and parts with which it sympathizes greatly, as the testicles, upper part of the intestines, &c, the pulse is small, quick, and contracted. Of the sensations arising from inflammation in different parts.— When the injury is in the head, the pain is often dull and attended with sickness; when in the heart and lungs, the pain is more violent. When in the stomach or upper part of the intestines, it is a heavy depressing pain, and attended with more or less of sickness. When in the colon it is more acute, but attended with less sickness. When the liver, ligaments, or bony parts are affected, the pain is much the same as when the stomach is affected, that is, heavy and depressing : the pain is acute and rousing when the skin, cellular membrane, or muscles are inflamed. Inflammations in vital parts do not all produce the same effects on the constitution, which would seem to arise from their greater or less sympathy with the stomach; but it is certain that a given quantity of inflammation in a vital part or its sympathizer will produce much more considerable effects than a greater quantity in another part, and the blood will be more sizy. When the heart is inflamed, its actions are irregular; if the lungs only are inflamed, the heart still seems to sympathize, and is irregular in its actions, as well as weak. If the stomach is inflamed, the patient feels a depression and a defective action in the heart as well as in every part; simple animal life, or the living principle, seems then to be depressed, as the sensitive from inflammation in the brain, and the pulse is low and weak. In inflammation of the uterus the pain is very acute, and the pulse quick and low, the stomach sick, &c. When inflammation occurs in these parts the symptoms come on very quickly; and if it proves fatal, it runs through its stage very fast; debility beginning very early. All this may depend on the stomach being, as it were, the central seat of sympathy, whence the actions of life are interfered with. However, universal sympathy soon takes place here, and the sympathy being similar to the first action, a fever of a depressing kind is produced, and death soon succeeds. Inflammation of parts not vital, of such violence as to affect the actions of life by general sympathy, render the pulse full and strong. The constitution in this case is strong and not irritable; for when weak and irritable, the pulse is quick, hard, and small in the beginning, as it is in inflammation of vital parts, and the blood though sizy is loose in its texture. Difference from different nerves.—One cause of the difference in the inflammation of vital parts seems to be the different systems of nerves by which they are supplied. In all those parts supplied by the par vagum, inflammation affects the patient with lowness from the first, these nerves supplying the parts of involuntary motion, and therefore possessing the living principle in the highest degree ; whence an inflammation of these parts becomes peculiarly depressing. Situation of ihe blood in the commencement of diseases.—In some diseases the blood at first forsakes the skin, extremities, and lips, and GENERAL PRINCIPLES OF INFLAMMATION. 161 the parts shrink and diminish in bulk; this is particularly evident in the eye, and arises from want of power in the constitution, all the powers being called to the citadel, or source of power, and the outworks left. This happens in fainting, agues, hectic, &c.,and does not seem to arise from debility at first, but from a novelty of action, and a consequent inability to perform it. In putrid fevers the external parts first loose their living power from having a less resisting power. Of the Effects on the Constitution from, different stages of Inflammation.—The constitutional effects arising from inflammation, independent of the difference of parts, situation, nerves, &c, are more or less according to the stage of the disease. When inflammation is in the adhesive stage, it has but little effect on the whole system, and that effect is generally an increase of animal actions. This stage is the one which should be considered as truly inflammatory, as in it the constitution appears to be more regular, more determined, and more at ease, for it is more steady, more capable of continuing the time of action than in any other, hardly any varieties taking place in the time of this stage of the disease. When the suppurative stage comes on, the effects on the constitution are much more considerable and more various. Cold fits or rigors are generally felt on the commencement of suppuration; but they are not lasting, and are often succeeded by hot fits, both being more or less according to the greatness of the present inflammation and the suppuration that is likely to follow, as indeed with the nature of the parts, and their situation, whether vital or not, &c. Cold fits show plainly the commencement of some new action, as the beginning of fever, the absorption of poison, or even from simple irritation, as pricking the finger with a clean needle. They may also be produced by disagreeable sensations and disagreeable states of the mind. These rigors are probably dependent on the stomach, which being the seat of simple animal life and the seat of sympathy, takes part in every constitutional alteration, and we observe how much this viscus is affected by loss of blood, disagreeable sights, &c. What nature intends to effect by this sympathy with the rest of the body it is hard to say, but it is worthy inquiry whether she may not intend to relieve herself by rousing the actions of life by means of vomiting. Rigors seem to be the effect of any new action in the constitution, and not at the commencement of a disease only, for even at the close, changing from a diseased action to a healthy one will cause rigors to take place. In a strong constitution, where rigors occur in consequence of a well-formed fever, the consequent actions of a hot fit and sweating go on regularly; but in a weak constitution there is much loss of power by each rigor, and they will not be followed by a hot fit, but only perhaps by a little sweating. A boy was attacked with rigor, followed by sweating, and he afterwards continued getting sensibly worse and worse: pulse quick and full, blood sizy, tongue white. He was worse every 14* 162 HUNTER'S PRINCIPLES OF SURGERY.

other day. After being ill a fortnight, he was again attacked with rigor, hot fit, and sweating, which, contrary to my expectation, who supposed these would be repeated, carried off the disease with that single fit. I think I have seen other cases where Nature has attempted something like this, but has failed. In many cases the rigor is the first apparent symptom, and is followed by a hot fit, and then sweating, and when these whole actions of the disease have taken place the patient becomes well; but this is not the case where, from weakness, &c, the whole regular actions do not take place, but, as at the commencement of the boy's case above related, the hot fit does not succeed the rigor, and he continued ill afterwards until Nature again took on the rigor, and he was able to go through the stages regularly, and one fit carried off the disease. The boy above mentioned was also a striking instance of the crisis of a disease being like its commencement. Rigors from a local affection are seldom followed by a hot and sweating stage, and the bark in such cases can be of little service. The ulcerative stage seldom affects the whole system ; but that rigors take place on the commencement of ulceration is, I think, certain, although it cannot be well perceived in all cases, for ulceration will follow so close on suppuration in most cases that it will be difficult to distinguish which was the cause of the rigors. But when suppuration has taken place, and the abscess been opened, (so that the act of suppuration is finished,) yet not so opened as to afford a ready outlet to the matter, the pressure of the matter against the most depending part of the abscess will cause ulceration, and thereby rigors will take place ; but these rigors will not take place for some time after the first opening, for the first opening will for a time remove the disposition for ulceration all over the surface of the abscess ; but when it finds this opening not sufficient to take off the pressure, it then sets to work to make another, and the rigors return. Many have supposed from these rigors that new matter was forming. Exacerbations are other symptoms, which have a great affinity to the foregoing, and are common to most constitutional diseases, and to some local ones. They are repetitions of the first attack, but seldom so strong as the first. These have been supposed to be owing to the disease acting on the constitution at stated times ; but we must search for some principle in the animal economy to account for this, for we cannot suppose an increase and decrease in the cause of disease to aceount for it. Agues exist in the constitution as much between the fits as in them. If the constitution is strong, the exacerbations are regular; if weak, irregular. These may be partly owing to the fact that an animal cannot exist for long together in the same state; life cannot always be affected in the same way. Of the state of the blood in Inflammation.—It is reasonable to suppose that the blood is affected in the same manner with the con- GENERAL PRINCIPLES OF INFLAMMATION. 163 stitution, and that disease has nearly the same effect on it that it has on the body, because the same living principle runs through the whole. We find this to be really the case ; for till the disease has affected the constitution the blood continues the same as before; but as the constitution becomes affected the blood also becomes affected, and undergoes changes which are probably owing to contiguous sympathy between the vessels and the blood. So that we shall find that the changes in the blood are often as expressive of disease as in any other part of the body. When the action of the solids is of the inflammatory kind, or what is perhaps the same thing, when there is too great action of the solids, the blood under such a disease more readily admits of a separation of its component parts (see p. 32, note) ; the red particles subside more to the bottom of the coagulum, and the coagulation of the lymph, though more slow, is firmer; the upper part of the coagulum being of an opake white, in which state the blood is said to be sizy. It is not easy to say whether this change in the blood is not the first produced, and that the constitutional is not an effect of the change. I have before said that I can conceive the death of the blood to take place independently of the solids, and it appears to me that the diseased state of the blood is capable of coming on as suddenly as the corresponding state of the solids. A man received a stab in the abdomen. I saw him a little time after the accident, when there was no degree of fever or constitutional affection, but he complained of considerable pain; I therefore took away some blood from him, which was entirely in the natural state : in about a quarter of an hour constitutional disturbance came on, and the blood appeared very sizy. Whether the disposition for inflammation and the change produced in the blood arise from a real increase of animal life, or whether it is only an increase of the disposition to act with the power that the machine is already in possession of, is not easily determined: but it appears certain that it is either the one or the other. However, some circumstances incline me to suspect that it is the last, because we often have inflammation when the powers are but weak, where there appears to be only an exertion of very weak powers, arising from some irritation produced. This appears to be equally the case in local inflammation and inflammatory fever, or the symptomatic fever. On the other hand, there are some reasons for thinking it may be a real increase of animal life, for women who are breeding, and who are in perfect health, have yet sizy blood: and this is the case with all animals in a similar situation. Now it would appear necessary for an animal, when put into a situation where greater powers are wanted, that these powers should be increased. In breeding females there is a process going on which, though natural, is uncommon, and which requires a greater quantity of power than usual; therefore we have greater powers produced. 164 HUNTER'S PRINCIPLES OF SURGERY. If these observations are just, the blood should not be inflammatory blood, but blood whose powers of life are increased. On the other hand, where there is great debility in the solids, where the powers of preservation are less, and therefore action weak, where the body must therefore have a tendency to dissolution, we find the very reverse of the former appearance in the blood; there is no distinct separation, but the whole mass continues mixed. This effect takes place in those who die instantaneously, and I suspect that the blood dies first, and instantaneously. When the pulse is quick and hard, and has a kind of vibratory thrill, we generally have sizy blood. This may arise from fever, or such inflammation, &c, as affects the constitution or the vital parts, these being diseased, so as to keep up a constitutional irritation, which will always be an attending symptom. But when we have neither a quick nor hard pulse, but rather small, no visible fever nor inflammation, but perhaps some strange and undetermined symptom, such as pain, which is moveable, sometimes in one place and sometimes in another, yet seeming to impede no natural function, we shall nevertheless, on bleeding, find the blood sizy, as happened in a gentleman who had severe pain shifting about, with a small slow pulse : he was blooded, and the blood found sizy. After the bleeding the blood became fuller and harder, and did so after every bleeding, which, on account of this circumstance and the continuance of the pains, was repeated several times. Something like this is observable when an oppressed pulse becomes liberated by bleeding ; but what was remarkable here was its increasing in hardness. We may even have the blood contract so strongly in these cases as to cup. So that the pulse and the appearance of the blood do not always agree with one another. The manner in which inflammation begins is generally from a point. It afterwards spreads from this in proportion to the violence and the disposition of the surrounding parts. This is the case in accidents ; the accident is limited, but the inflammation arising from it is not; it is most violent in the first point and gets weaker and weaker as it spreads from this until it is lost insensibly in the surrounding parts. This extension is owing to sympathy; and hence, according to the susceptibility of sympathy will be the spreading; and from the difference of disposition to sympathy will result great differences as to the diffusion of inflammation ; the more healthy the less the sympathy. Swelling of the parts in inflammation, like the inflammation itself, is greatest in the middle, and gradually lessens from that till it is lost in the surrounding parts. It is owing to the extravasation of coagulable lymph and some serum being squeezed out as the coagu-. lable lymph thickens, and is deposited around the inflamed part,, causing cedema, which is less in proportion as the parts are healthy. Of the colour of inflamed parts.—The colour of an inflamed part is visibly changed from the natural hue, whatever it was, to reds This red is of various hues, according to the nature of the inflam-. GENERAL PRINCIPLES OF INFLAMMATION. 165 mation; if healthy, of a pure scarlet red; if less healthy, the colour is rather more of a purple, and so on till it shall be of a bluish purple. This increase of red would appear to arise from two causes; first, dilatation of the vessels, by which a greater quantity of blood is sent into those vessels which naturally admit only serum or lymph (an example of which we have in the conjunctiva of the eye when inflamed); and secondly, the formation of new vessels in the extravasated uniting coagulable lymph. From which circumstances there is a greater quantity of blood in the part than in a natural state, according to that law of the animal economy, that where a part has more to do than to support itself, red blood is thrown into it in larger quantities. The true inflammatory colour is scarlet, that colour which the blood has in the arteries ; hence we should suppose that the arteries were chiefly dilated, or if the veins are equally distended, that the blood undergoes no change in such an inflammation in the passage from the arteries into the veins, which last I think most probably the case. Heat of the inflamed part.—The inflamed part is hotter than common; but this is most obvious in the skin, from its being a part most disposed to carry these sensations to the brain. Heat, I imagine, is a sign of strength and power in the constitution, though it may often arise from increased action in weak constitutions or weakened parts. It is an immediate action, while cold is the reverse, and often arises from a diminished action of strong parts. It has not been considered whether an animal has this power equally in every part of his body, though from what is generally advanced on this subject, it is probable that it exists in every part. Nevertheless, I am inclined to suspect that there is a principal source of heat, though I do not think with many that this source is in the blood, but rather that this is affected by the source of the blood being near to the source of heat. That this principle resides in the stomach is probable; at least of this I am certain, that affections of the stomach will produce either heat or cold. Eructations often give a sensation of heat, but whether this is increased heat, or only a sensation, it is difficult to say. Certain substances taken into the stomach produce a glow. Certain affections of the mind also produce a glow. This would appear to contradict my opinion, but I suspect that the stomach sympathizes with the mind. We find that inflamed parts become hotter; but let us see how far the increase goes. From all the observations I have made, I do not find that a local inflammation can produce local heat above that which is natural to the animal; and when in parts whose natural heat is inferior to that which is at the source of the circulation, it does not rise so high. A man had the tunica vaginalis laid open for the cure of hydrocele; I introduced a thermometer into the wound, and placed it in contact with the testicle, and it stood 166 HUNTER'S PRINCIPLES OF SURGERY. at 92°; by night it had risen to 98|°, a rise of 6J°: but this is not greater than the heat of the blood at the source of the circulation. A wound was made in the belly of a dog, and the bulb of the thermometer immediately applied to the diaphragm, which gave 101°, and did not increase above that. Another dog's rectum gave 102°, and when inflamed very much, which it was by injecting a solution of corrosive sublimate, the heat was not increased a degree. The rectum of an ass, 98°, was injected with a strong infusion of mustard and ginger several times repeated, but without increasing the heat at all, nor did a strong solution of corrosive sublimate have this effect: at last a much stronger one was injected, which brought on a very violent inflammation, but the heat was only increased to 100°. A similar experiment was made with nearly the same result on the vagina of the same ass. Also a wound was made deep in the gluteus muscle of the same ass, and in no stage of this wound did it raise the thermometer above 100°. A wound was made in the belly of the same ass, and an injection of a strong solution of common salt thrown into the belly, which produced violent inflammation, and even symptomatic fever; yet the heat of the part was very little altered. From all which observations and experiments I do not find that a local inflammation can increase local heat above the natural heat of the animal; and when in parts where the natural heat is inferior to that at the source of the circulation, it doce not rise even so high. Yet, that in some instances the heat of the parts may be increased beyond its natural degree in those parts which have the greatest natural heat, is certain from the following experiment; the bulb of the thermometer being held in the stream flowing from the abdomen of a man tapped for dropsy raised the mercury to 104°. In most of the above experiments there seemed a difference of 1° between the heat at night and in the morning, and this difference seems to exist in the natural state of the body. I suspect that the blood has an ultimate standard of heat in itself when in health, and that nothing can increase that heat but some universal or constitutional affection, and that the whole power of local inflammation is only to increase it a little in the part, but cannot bring it above the standard heat of the constitution, nor even to it in parts far from the source. Of Cold.—The production of cold certainly is an operation which the more perfect animals have a power of performing. (See p. 82, note.) I suspect that coldness in disease arises from weakness of the whole constitution, joined with a peculiar mode of action at the time. That universal or constitutional cold arises from the stomach is evident, for whenever we are made sick universal coldness takes place. This is best proved by producing sickness in animals that we can kill while under the influence of the affection of the stomach. I threw three grains of emetic tartar into the stomach of a bitch, and repeated the experiment with a grain more: she vomited and GENERAL PRINCIPLES OF INFLAMMATION. strained very hard, and brought off a good deal of froth, that is mucus, from the stomach, mixed with air in coming up. I opened her body, and, contrary to what we generally observe, I found the intestines, liver, and heart not warm. I have known people who had affection of the stomach say that they had plainly a feeling of coldness in their belly. I knew a gentleman who said, whenever he threw wind off his stomach it felt cold even to his hand. Affections of the mind also produce general coldness, but such effects arise from the sympathy of the stomach with the mind, producing there such a sensation as we mean by the expression " turning the stomach with sickness:" the sensation proceeds to the shoulders, which, with the rest of the body, are put into motion by wrhat we term shuddering. Of Pain in Inflamed Parts.—The immediate cause of sensation is an alteration in the natural position of the solids, arising either from violent action or mechanical or chemical effects,* joined with its being produced in a given time; for this alteration may be produced so slowly as not to keep pace with sensation, as in many

* [It must be confessed that we are very much in the dark respecting the proximate cause of pain ; for being ignorant of the ultimate distribution of the nerves, as well as of their mode of action, we cannot say in what manner they may be affected; indeed, we cannot positively say that pain depends on the nerves at all, for those parts which are most painful when inflamed have the fewest nerves, and these do not enlarge in consequence of inflammation in the same manner that the vessels do. Pressure is a well-known cause of pain, and therefore has been assigned as the cause of pain in inflammation, for not only are the minute vessels distended from within and pressed upon without, but the natural sensibility of the parts is exalted by the increased vascularity. This is further confirmed by the exquisite pain occasioned by inflammation when it occurs in any unyielding texture, as the teeth, the bones, the periosteum, the serous and fibrous membranes, &c, as well as by the relief which is afforded by such means as tend to diminish the tension of the inflamed parts, as bleeding, scarifications, fomentations, &c. It may, however, be urged on the other side, that the pain is not proportioned to the quantity of nerves, as in fibrous membranes, bone, teeth, &c; nor to the quantity of effusion and consequent swelling, as in serous membranes ; nor to the quantity of inflammation present, as in gout, rheumatism, &c: that the difference in the quality of the pain is inconsistent with any mechanical explanation, which would occasion differences in degree but not in kind ; that it is irreconcileable with the sudden transition of pain from one part to another, as in metastasis ; that chemical substances cannot be supposed to act in this way ; and finally, that pain often occurs without its being possible to assign any probable source of pressure as a cause, as in colic, tic-douloureux, tooth-ache, and many other forms of nervous disorders. It seems, therefore, most probable that pain depends on some peculiar action of the nerves with which we are unacquainted, but to which pressure stands in the relation of an exciting cause. Pain is the most general symptom of inflammation. What other purpose does it answer besides that of inducing the patient to repose the inflamed parti Does it answer any direct purpose in the economy ? Intense pain occasions increased vascularity of the affected part, and if continued, excites inflammation. This is seen in tooth-ache and tic-douloureux, which inflame the face, and in disease of the hip, which occasions inflammation of the knee ; on the other hand, whatever diminishes the pain diminishes the inflammation also.] 168 HUNTER'S PRINCIPLES OF SURGERY. indolent tumours; or, on the other hand, this alteration in the natural position of the parts may be so quick as to exceed sensation. (See p. 56.) Pain is not the same in all the stages of inflammation. In the adhesive stage it is generally but inconsiderable, especially if it is to go no further, and is perhaps more a heavy than an acute pain. But when the inflammation is passing from the adhesive to the suppurative, the parts are undergoing greater change, and the pain gets more and more acute until it becomes very considerable and becomes pulsatory, being increased during the dilatation of the arteries. The nerves, too, acquire a degree of irritability which renders them much more susceptible of impression than in a natural state. When suppuration has taken place, the pain in some degree subsides; however, as ulceration begins, it in some degree keeps up the pain, and this more or less according to the quickness of the ulceration. The pain attending ulceration gives more the feeling of soreness. Of the Subsidence of Inflammation.—Whatever disposition it is which produces inflammation, and whatever the actions are which are produced by this disposition, yet when the disposition arises either from the constitution or part, it can be removed, and of course the actions raised in consequence of it cease. If the disposition for inflammation has taken place, and the vessels, which are the active parts, should have dilated thoroughly, they will allow the blood to enter them, so that the part shall look red; but no hardness or fulness shall be observed, and the whole will subside before adhesions have taken place: or if inflammation is gone so far as to produce swelling, which is the adhesive state of the disease, yet by certain methods it can be assuaged, and suppuration be prevented from taking place, and then the parts will fall back into their natural state, which is called resolution. And as the first symptom of inflammation is pain, the first symptom of resolution is the cessation of pain. Why an inflammation of any kind should cease after it is once begun is very difficult to explain, or even to form an idea of, unless it is on the principle of what I call custom that the parts adapt themselves in time to their present situation ; and therefore, in order to keep up inflammation, it is necessary that the cause should increase in proportion as the parts become reconciled to their present circumstances. But this will not account for their returning to their original state when this increased irritation ceases. We may suppose that the removal of the original cause is sufficient to stop the progress of inflammation; and when stopped, the parts cannot easily remain in the inflamed state, but by their own efforts begin to restore themselves to health, like a spring which is bent by a weight, but the moment the weight is removed the spring returns to its former state. Restoration of injured parts.—All alterations in the animal frame arise from a disposition to act, and these preternatural actions, in consequence of injuries, may be caused,—1st, by a disposition to GENERAL PRINCIPLES OF INFLAMMATION. 169 restoration, in consequence of injuries, which is the most simple ; 2d, by a disposition of necessity, as thickening of parts, ulceration, &c.' which is rather more compounded: 3d, by disease, which is the most complicated (p. 97.) There are a great many cases requiring the assistance of a surgeon but which cannot be strictly called disease, but are injuries done to the body. In disease there is a disposition to wrong action, which goes on until the disposition is worn out, or is put a stop to by remedies ; but the actions in consequence of accident are widely different, for here, by reason of the stimulus of imperfection in the injured part, a disposition to restoration is excited, and action, different from the former comes on. In disease the restoration to health is produced by a prevention of the continuance of diseased action ; in injuries, or alteration of structure by violence, something is required different from the ordinary and natural actions, which will differ in some respects according to the nature of the violence and of the part; and this alteration is of the most simple nature, being the action in consequence of a disposition to restoration, and consequently if it requires any assistance from art, it is of the most simple kind. The affections from accidents may be divided into two kinds, those which take place in sound parts, and those in parts before diseased. The first I shall only treat of now. Accidents, then, may be divided into two kinds ; first, those which do not communicate externally, as bruises, sprains, ruptured tendons, simple fractures, ccc.; secondly, those which have also an external communication, as compound fractures, wounds, &c.; yet these may be, and often are, brought under the first head. Bruises, which have destroyed the life of a part, might be considered as forming a third head. The first class, when in a simple state, requires a most simple treatment; but they may be so complicated as to require our utmost exertion. The most simple of these is the bruise, when the continuity of parts is not broken through; here the parts have nothing to do but recover themselves. The rupture of a small vessel is next, the blood being effused into the cellular membrane ; but the vessel must not be in a part of any consequence to life, or the extravasation may kill, as in the arteries of the brain. The cure in this case will be next in simplicity, the vessel being closed by the contraction of its muscular coats, and the union effected by means of coagulable lymph, and the extravasated blood being taken up by the absorbents. The differences in these cases wiir arise from the magnitude of the injury and the nature of the injured parts. Some accidents of the first class, as fractures, will require the aid of a surgeon to restore the parts to their natural situation, and then nature falls to work and completes the business. Sometimes the quantity of blood extravasated is so large as to prevent nature from going through these processes directly, and forms a tumour called an ecchymosis. Ecchymosis may be said to be of two kinds ; one is where the blood coagulates; the other where it does not. That which coagulates commonly subsides gradually, from the blood being absorbed, and gives but 170 HUNTER'S PRINCIPLES OF SURGERY. little trouble, which is likewise the case sometimes with those in which the blood does not coagulate, though not generally. I have seen where a small wound has led to the cavity containing the coagulum, which not being meddled with, the sides of the cavity have gradually contracted, and have as gradually squeezed out the coagulum. A woman fell with the labium pudendi on the edge of a pail. I found a very considerable tumour, which I thought was of blood ; there was evidently a fluctuation. I bled her, and ordered a poultice, but did not open it, as I thought the presence of the extravasated blood might serve to stop the orifice of the vessel. In a little time the tumour burst, with a small opening, and on examining with a probe I found the coagulum filling a space the size of a goose's egg. The cavity grew less and less, but always kept exactly filled with coagulated blood ; and thus it continued diminishing until the orifice healed. Thus the blood being allowed to remain in the cavity, and not acting there as an extraneous body, nor even allowing the stimulus of an imperfect cavity or inflamed surface to take place, the cavity continued to contract all round the blood until the whole had disappeared. Now what would have been the consequence if I had followed the old method of laying open the tumour, scooping out the blood and dressing the internal surface with turpentine 1 I should have had a sore of the whole extent of the tumour, and given considerably more trouble both to the patient and to myself. The second species of ecchymosis, or that where the blood does not coagulate, does not always terminate so well as the former. It has often the appearance of an encysted tumour, but from being the immediate consequence of some accident to the part its nature is understood. The cause of this blood not coagulating must arise, 1 conceive, from some peculiar mode of action of the vessels arising from the injury, for I apprehend that in such cases the blood dies as it is extravasated, or in the act of extravasation, like the menses. This species of ecchymosis happens very commonly to children in birth under the scalp. In such cases nothing should be done but to wait with patience, and the whole will be absorbed. In many cases the accident has been so violent as to deaden the cellular membrane under the skin, or as to produce inflammation in the surrounding parts; these sometimes resolve, but they are seldom allowed to do so ; for surgeons are led to open them early, from seeing the inflammation and feeling fluctuation, two strong enticements to use the lancet when all circumstances are not well attended to. But in such cases I should wait until I saw the signs of suppuration, viz., thinning of the skin over the matter and pointing of the contents, which are the only true marks of the formation of matter and of its approaching the skin. Sometimes ecchymoses are removed by pressure, which without this would remain. Parts cannot bear pressure, so that the extravasated blood being pressed against the sides of the cavity, the absorbent vessels are under the necessityof absorbing it. When ecchymoses are not absorbed, but suppurate, abscesses are formed, which must be treated as abscesses in common, only GENERAL PRINCIPLES OF INFLAMMATION. 171 waiting with a little more patience than when wholly the consequence of inflammation. In many of those cases of accident not only the skin shall be deadened, in consequence of which it will slough and leave a sore, but often the skin shall preserve its living powers, and only the cellular membrane underneath shall be deadened and slough, and produce an abscess, which was not at first expected. In cases where the skin in one part is killed by a blow, and the cellular membrane in another part, while the skin over it will remain sound, the deadened skin will come off, granulate, and heal kindly ; but then inflammation shall take place, perhaps, an inch or two from it, where the cellular membrane was deadened, and an abscess shall be produced. If these injuries are not very great, little effect will be produced on the sensitive principle, no sympathy or irritation taking place ; but sometimes the accident will, by its irritation, produce another action of the parts, causing inflammation, the end of which is either adhesion of the divided parts or suppuration for getting rid of the substances become extraneous. The most simple accident may be attended with such circumstances as will prevent the more simple process of nature from taking place; such, for instance, as the magnitude of the vessel ruptured, or a fractured rib wounding the lungs, &c. The second division I made was where wounds communicate externally.—These are subject to greater variety than the former, yet often admit of the same mode of cure. A wound may be either simple or compound. The simple, which is what I mean to speak of now, is a solution of continuity in a part, which must be made with a cutting instrument. In such cases a number of vessels are always divided, blood is effused, and the cells of the cellular membrane exposed, as well as other internal parts. The former class required only rest, but in these there is a necessity for replacing the divided parts. The present class admit of both a natural and an artificial cure. By the natural is meant union by the first intention ; when this cannot be obtained, a new bond of union takes place—adhesive inflammation ;* and if this is lost, a third modegranulation. In that by art we have to imitate the natural, we are to bring the divided surfaces into contact; the living extravasated blood being then retained and coagulating, unites them ; the mouths of the vessels shut, and the remaining blood is absorbed: the red globules are indeed absorbed, and only the coagulable lymph remaining becomes the bond of union.t This is an imitation of * [Union by the first intention and adhesive inflammation are in the present day generally considered to be synonymous.] f [It has been before observed that the blood does not become vascular, but only the coagulable lymph which is subsequently effused. The blood at first serves the useful purpose of uniting the divided parts ; but beyond this it unquestionably is an impediment to union by the first intention. Wherever, therefore, union by the first intention is desired, the incised surfaces should first be cleansed of adhering blood previously to their being put into apposition. This rule of practice is universal.] 172 HUNTER'S PRINCIPLES OF SURGERY. nature ; but surfaces cannot always be brought to unite in this manner, and the blood in some parts loses its living principle, and then it becomes a source of irritation, exciting inflammation, which is the case sometimes in simple fractures, and which I shall call, for distinction's sake, simple compound fractures. The best time of replacing the divided parts is perhaps during the time that the extravasation continues, but it may also be done when the discharge of coagulable lymph in the adhesive or first stage of inflammation takes place. Sometimes the inflammation runs so high as to get into the suppurative stage; the extravasated fluids may lose their living principle, and become a stimulus exciting inflammation. By adhesive inflammation different parts of the body may be united to another by coming into contact; but the most extraordinary union is that of removing parts from one body and uniting them to another. Here is the testicle of a cock, separated from that animal, and put through a wound made for that purpose, into the belly of a hen; which mode of turning hens into cocks is much such an improvement for its utility as that of Dean Swift when he proposed to obtain a breed of sheep without wool. The hen was afterwards killed, and the testicle was found adhering to the intestines, as may be seen in this preparation, where the parts are preserved. Here is another preparation, in which the spur of a cock has been inserted into the comb of another; and here a human tooth, inserted into the same part, and united by means of vessels, which you see injected, from one to the other. These living bodies thus applied to each other produce adhesive, not suppurative inflammation. In the same manner, the eggs of one animal laid in the flesh of another do not excite suppurative inflammation. This would not be the case if the inserted body did not contain the principle of life, for the part would run into suppurative inflammation, as would be the case with a pea so introduced. While the guineaworm is endowed with the living principle it gives but little trouble; yet if killed it gives the stimulus of an extraneous body, which produces suppuration through its whole length. In this preparation you see a maggot deposited, just below the skin, on the back of a reindeer: here the first stage of inflammamation took place only; coagulable lymph was poured out, which has formed a chamber in which the insect resided. A similar power is observable in vegetables. Here is an oak leaf, which I picked up in my garden; you observe on it seven or eight protuberances, exactly circular and uniform. These have been formed by the insertion of the eggs of an insect into the leaf; and I cannot but think the process would have been different if any substance not possessed of the vital principle had been inserted. It is on this principle of union by the first intention that the union of parts by suture has been recommended, which has been found the best practice where it can be done. The dry suture in superficial wounds answer very well, the quilled is sometimes useful, and the inter- OF ADHESIVE INFLAMMATION. 173 rupted is very often useful. The two last are properly called sutures. In many cases it is improper to keep the surfaces together, as when the wound has been attended with considerable contusion, which generally occasions sloughing of the parts. When much blood is extravasated, suppuration becomes necessary, in consequence of the blood acting like any other extraneous body; but when laceration only is present, union by the first intention may take place, especially when on the head and over other superficial bones, as Mr. Cline has observed. The machine is not at all disturbed by this most simple operation; there being perhaps even no local action except the contraction of the vessels, the union being performed by the blood only. CHAPTER XIII.

OF ADHESIVE INFLAMMATION.

Natural tendency of inflammation.—Definition of inflammation.—-Seat of inflammation.—Adhesive inflammation ;—why limited, and how ;—its tendency ;— arisino- more easily in some parts than others;—lymph affected by the state of the parts secreting it;—appearances of inflammation ;—redness ;—swelling;— pain.—Adhesive inflammation; its use, in large cavities;—in the cellular membrane;—in the lungs ;—compared with erysipelatous inflammation ;— sometimes imperfect;—consequences of this imperfection ;—constitutional effects of this inflammation.—Of resolution ;—cases in which it is supposed to be improper;—modes of by constitutional means;—by weakening;— by temporary weakness ;—by lessening irritability.—Venesection ;—medicines ;—local applications.—Treatment of adhesive when about to end in suppurative inflammation.

Although inflammation is an action produced for the restoration of the most simple injury in sound parts that exceeds union by the first intention, we must still look upon it as one of the most simple operations of nature. It is to be considered only as a disturbed state of parts, which require a new but salutary mode of action to restore parts to that state in which the natural mode of action will be necessary. But this same operation can and does vary, and is often carried much further than union, according to circumstances: and is often attended with disease, and that of various kinds, by which means it becomes more and more complicated. It becomes therefore necessary to begin by describing it in its most simple form, and with its most general effect, and to particularize further as we go on. I shall call everything inflammation that produces the following local effects, viz., pain, swelling, and redness, all depending on one cause, and occurring at the same time. Out of inflammation arise many other local effects, which may be called secondary; such as 15* 174 HUNTER'S PRINCIPLES OF SURGERY. adhesions, suppuration, ulceration, and even death or mortification in the part, and universal affection, such as sympathetic fever, and universal death. The act of inflammation is, as I have said, most probably in the smaller vessels. What the action is, or in what it differs from the common action of these vessels, is not easily ascertained; for we are better able to judge of the immediate effects than of the immediate cause. Hitherto I have only shown that this inflammation takes its rise, and is capable of uniting parts, when preternaturally divided, but we shall find that it is capable of arising from very different causes, and that it is capable of producing adhesions in whole parts, or in natural separations, such as common cellular membrane, large circumscribed cavities, joints, &c, and these effects will be found to answer very important purposes. As the adhesive inflammation precedes the suppurative in every part excepting the outlets, and the suppurative the ulcerative, the propriety of following this order of nature in treating of them will appear evident.

Adhesive Inflammation.—If the actions of adhesive inflammation were allowed to extend themselves, ft would prove more hurtful than any good that could arise from it; hence there are natural obstructions to its extending, which we shall first consider. JVatural Causes of the limiting of Adhesive Inflammation.—I have already observed that exposure of internal surfaces becomes the immediate cause of inflammation; that when it extends further than the exposed surface it is by continuous sympathy ; and that when a whole cavity is wholly exposed, the whole would take on inflammation. We may now observe, that whenever a cavity is opened, the simple contact of its sides, or even the simple con-tact of these with any other living part, will set bounds to the immediate cause, which is the exposure. To explain this further, we may observe that there is no such thing in an animal as an empty space in any of the circumscribed cavities of the animal body, exclusive of the outlets or reservoirs, which are imperfect, not being circumscribed. Every other part of an animal is either connected by the cohesion of one part with another, or by simple contact. This holds good too in the cellular membrane as well as the circumscribed cavities: for if a wound is made into either, we find that the surfaces of both, beyond the cut edges, are entire, and generally in contact with one another. To explain this position, let me instance a case. If wc make a wound into the cavity of the belly, in a sound state of those parts we shall find every viscus is in contact with some other viscus, and that the whole inside of the peritoneum is in contact with the viscera so that no space is unfilled. If this wound is not allowed to heal by the first intention, still we find that no inflammation will take place, or extend further than the attachment of those parts to the cut OF ADHESIVE INFLAMMATION. 175 edges, excepting what is owing to continuous sympathy. If this were not the case, every part of the cavity must inflame, because every part would be equally exposed; and if the contact were removed at the time of receiving the wound, or at any time afterwards, the whole cavity must inflame, every part being in the same predicament as regards exposure. The same thing would happen in the cellular membrane, if those cells were not in a natural state in contact, and inflammation would as readily extend over the surface of each cell as air does when blown into part. Inflammation, then, takes place at the edges of the exposed parts in order to preserve this contact, as well as to serve as a basis for future operations: and in cases of spontaneous inflammation of circumscribed cavities, we find that where this contact is completest the inflammation and its consequences are the least; as in the belly, in cases of peritoneal inflammation, the inflammation is greatest in the angles between the viscera, where the parts are not so well in contact. The effect of simple contact, in excluding the irritation from extending, was well illustrated in a woman who had the Caesarian operation performed. After the child was extracted, the wound could not be brought together well, therefore so far gave rise to peritoneal inflammation; but the belly closing and falling in on its contents, the whole came in contact as before. The woman lived twenty-six hours, which gave time for the inflammation to take place. After death it was found that the intestines were united to the peritoneum all round the wound, for above half an inch in breadth, and the surface of the intestines, which lay unattached at the bottom of the wound, was inflamed, while every other viscus, as also the peritoneum beyond the adhesions, were free from inflammation. The adhesive inflammation seems to be nearly of the same nature, whether it arises from the constitution, from a particular disposition of the part, or from some violence inflicted on the part; the final intention being nearly the same in all these cases, for in all it is an effect that has a tendency to repair an injury, as is evidently shown in many cases of violence, though it may not in all. Its utility is most obvious in those cases which arise from the constitution, or from disease in a part. When the adhesive inflammation arises from the constitution, it may be from some disease of that constitution ; and, if so, it may be supposed to be of service to it, especially if it should be supposed to be the termination of an universal irritation in a local one, and by that means relieving the constitution of the former, as in gout. But where it is only a simple adhesive inflammation, I am rather apt to think that it is more a part of the disease than an act of the constitution, or termination of the disease. When it proceeds from a disposition in a part, it must be considered to arise from a disease of that part. Although in all cases and in all parts the adhesive inflammation is not absolutely necessary and preparatory for the suppurative inflam- 176 HUNTER'S PRINCIPLES OF SURGERY. mation, yet if it is in the cellular membraneor a circumscribed cavity, then its effects will prove salutary. It may indeed be considered absolutely necessary to prevent greater mischiefs, for very bad consequences wouldarise without it. The object of it in these parts is to unite the parts together for their future benefit by means of the coagulable lymph and serum thrown out, by which the extension of the suppuration will be limited. It would appear from observation that some surfaces of the body have a much stronger disposition to throw out coagulable lymph than others; or we may view this effect in another light, that some surfaces of the body do not so readily unite by exudation of the coagulable lymph as others do, and therefore on such surfaces there is commonly a much larger quantity thrown out than probably would have been if union would have readily taken place. Thus we see in inflammations of the heart that the coagulable lymph is thrown out on the external surface in vast quantities, while at the same time the heart shall not adhere to the pericardium. This extravasated matter is always of the same nature with that of the parts which produced it, which is a curious fact. If the disposition of the part is cancerous, the extravasated coagulable lymph is a poison, for on being absorbed it contaminates the absorbent glands, producing cancer; and probably the same takes place in every poison that is capable of irritating to inflammation and extravasation. Appearances of Adhesive Inflammation.—The part inflamed becomes redder than common, and redder and redder as it advances; the red being of a scarlet hue when the inflammation is healthy. The part becomes apparently more vascular than in a natural state, and most probably is really so, both from new vessels being set up in the old parts, and from the adventitious uniting substance becoming vascular. These new vessels become of use both in the state of adhesion and of suppuration; in the first to give powers of action to this new substance which assist in preventing suppuration, in the second to form a basis for the future granulations. In consequence of this extravasation the parts swell, which is generally in proportion to the inflammation, the swelling being probably most where the inflammation is greatest, that is, at the point of irritation, and it is gradually lost in the surrounding parts. The whole swelling appears like a part of the body a little changed, without containing any extraneous matter, and indeed is simply formed by extravasation of fluids, without their having undergone any material visible change. Such inflammations as approach to the skin often produce vesications, which are filled with serum and often coagulable lymph, both which are sometimes tinged with red blood. This arises from the violence of the inflammation producing an apparent degree of weakness, approaching to a death, in the connexions between the cuticle and cutis, the life being in this part very weak, for in the beginning of mortification and of the putrefaction of dead bodies it OF ADHESIVE INFLAMMATION. 177 is produced. This connexion of the cuticle is more or less destroyed in every inflammation of the skin. We seldom see an inflammation attack the skin but the cuticle comes off sooner or later. We generally observe it peeling off in flakes after the inflammation has subsided. The pain attending inflammation would not appear to be in all cases very acute, for many have very visible inflammations which do not give very much pain. However, this will vary according to the violence of the inflammation, or rather according to the quickness of its progress and its approach to suppuration; for when there is a quick dilatation of the vessels, and rapid extravasation of the juices, the sensations arising from such will be increased ; but in cases where its progress is slow, as from indolent tumours, the mind is hardly sensible of its progress. That it must sometimes be very trifling is shown by the fact that on opening dead bodies we often find strong adhesions where the friends of these persons had never heard during life of a single complaint. We also see cases in which this inflammation arises from violence, where it gives very little pain. A man shall be shot through the abdomen, and, if none of the contained parts are materially hurt, the adhesive inflammation shall take place in all the internal parts contiguous to the wound, yet no degree of pain is felt from this process. In many bruises and in simple fractures the pain from the inflammation is very trifling, although there may be much laceration of the parts.* Of the Uses of Adhesive Inflammation.—This inflammation may be said to arise in all cases from a state of the parts which they cannot remain in; therefore an irritation of imperfection takes place. It may be looked on as the effect of wise counsels proceeding from a consciousness of imperfection: nature is taking all the defensive precautions possible, for in all cases we shall evidently see it answer wise purposes, such as checking the suppurative inflammation, by making parts adhere which must otherwise fall into that state; and where this effect does not fully take place, it acts as a check to the extent of it, as we see in circumscribed cavities. In the tunica vaginalis, after the operation for hydrocele, the parts often collapse and unite to other parts of the same sac by adhesive inflammation, which prevents the suppuration extending over the

* [Redness, heat, pain, and swelling may each of them exist independently of inflammation ; and when they arise from inflammation, they may exist in every possible relative proportion among themselves. In judging, therefore, of the presence or degree of inflammation, it is necessary to look at the whole symptoms collectively. The redness and heat are generally in proportion to the original vascularity of the part conjoined with the momentum of the circulation ; the pain is greater in proportion to the denseness and inextensibility of the inflamed part, added to the acuteness of the attack and the quantity of nervous supply; the swelling is generally greatest where the reverse of these circumstances exists. Structure, however, is not the only circumstance whieh modifies these symptoms ; they depend greatly on the specific nature of the inflammation': the sting of a wasp produces infinitely more pain and swelling than an attack of erysipelas.] 178 HUNTER'S PRINCIPLES OF SURGERY. sac, so that partial collections of water again take place.* In still larger cavities, as the abdomen, where partial inflammations often take place, as after child-bearing or wounds of this cavity, we find this adhesion takes place, which either prevents suppuration altogether or unites the parts around it, and as the abscess enlarges the adhesive inflammation spreads, and thus excludes the general cavity. The same thing happens in inflammation of the pleura or surface of the lung. The cellular membrane everywhere in the body is united exactly in the same manner; the sides of the cells, as it were, sweat out the uniting matter, which, coming into contact with the opposite surfaces, joins them into one mass. The lungs are subject to two modes of action in inflammation; being so circumstanced as to partake of the character of both orders of parts, the circumscribed cavity, and the secreting surface or outlet. The cellular membrane of the lungs readily admits of adhesive inflammation, like the cellular tissue elsewhere; but the inner surface of the air-cells, like the urethra, passes directly into the suppurative inflammation, and the matter which is thus formed is obliged to be coughed up. It is, perhaps, impossible to produce inflammation of the one without the other, which is, perhaps, the reason why inflammation of these parts is treated with such bad success. We cannot give a better illustration of the use of the adhesions arising in consequence of this inflammation than to contrast it with the erysipelatous. How far this disease is to be ranked amongst inflammations I will not at present say; but it has some of the characters, as swelling, redness, pain, &c. The swelling arises, not from extravasation of coagulable lymph, but from serum: and it has other peculiarities, as being generally superficial, and spreading along the surface with an abrupt edge, which is, perhaps, owing to its specific character being always confined to the part affected. It has nothing of the adhesive character attending it which was not necessary; because this inflammation, being confined to the skin, seldom produces suppuration. But it sometimes happens, when erysipelatous inflammation attacks deeper-seated parts, that it suppurates ; and when it does so, it appears often to be a forerunner of mortification. A man was attacked with an inflammation on each side of the anus. It had such an appearance as might have been expected from the suppurative and erysipelatous inflammations joined ; it had an oedematous appearance. He was bled, and the blood appeared very sizy: he took physic, and was fomented. The next day the inflammation had reached the scrotum, where a fluctuation, with a gurgling of air, was felt. I now made an opening near the rectum, and in the scrotum, and let out a quantity of dirty-coloured matter. It continued to spread over the loins, scrotum, bottom of the abdo-

* [The old operation is here referred to, in which the tunica vaginalis was exposed by incision, and suffered to suppurate.] OF ADHESIVE INFLAMMATION. 179 men, &c, where I made openings, and out of which the cellular membrane hung like wet tow. In this case, the suppuration was diffused for want of the adhesive process preceding or accompanying it, by which means it would have been limited. Adhesive Inflammation sometimes imperfect.—Sometimes it happens that the adhesive inflammation is so imperfect that it cannot set bounds to itself, and still less to the suppurative. This may be owing to two causes; first, the violence of the inflammation and quickness with which suppuration ensues, that is, before the parts have sufficiently united; secondly, the inflammation may be, as I suspect it is, of the erysipelatous kind, especially when there is a tendency from the beginning to mortification. This mixture of the suppurative with the adhesive, or hurrying on of the suppurative, I have often seen in the abdomen of women who have been attacked with peritoneal inflammation after child-birth; and when these circumstances become the cause of death, we find matter mixed with coagulable lymph, as if formed together. The adhesive inflammation also takes place in cases where it is impossible it should produce the same good effects; as in wounds which are not allowed to heal by the first intention, as a stump after amputation, and many other parts. But it is one of those fixed and invariable principles of the animal machine, that, on all such irritations, the uniting process should be produced, although, like many other principles in the same machine, it cannot always produce the same salutary effects. So that although the wound is not allowed to, or cannot, heal by the adhesive inflammation, yet the parts go through the common actions consequent upon being wounded; first, they throw out blood, as if to unite the parts by the first intention; and then, the vessels contracting themselves, coagulable lymph, with serum, is thrown out, which has the effect, even in such wounds, of preventing a great extension of the inflammation, while the contraction of the vessels prevents the inflammation from running along their inner surfaces.* Effects of Adhesive Inflammation on the Constitution.—These effects are very slight, even when the inflammation arises from violence ; but the effects of those inflammations which are indolent in their progress are still more trifling in the constitution. This arises from the slowness of the alteration produced in the part, as it were, insensibly stealing on the constitution. We know that one effect of adhesive inflammation is the uniting of parts not intended by nature to be united, and which must thus

* [One of the most remarkable good effects of the adhesive inflammation consists in the gluing of parts together previously to the discharge of hurtful matters from the body, as gall-stones, fasces, urine, &c, which are frequently discharged in this way; the ulcerative and adhesive processes proceeding pari passu to effect the discharge, at the same time that the latter always keeps a little ahead of the former. If it were not for this beautiful provision of Nature, the great cavities of the body would frequently be exposed to fatal inflammation from such causes.] 180 HUNTER'S PRINCIPLES OF SyRGERY.

be made less moveable on one another: in fact, they must at first have little or no motion on one another, as occurs in the cellular membrane and circumscribed cavities: but it happens that motion is again obtained after a time by the elongation of the connecting part, which is effected by the repeated endeavours for motion. These uniting media are seen to become vascular. They are perhaps often the cause of many indescribable sensations, which cannot be called pain. In the heart they are the cause of palpitation, &c. On the Resolution of Inflammation.—Since an animal body can be made to act improperly by impression, we can see no reason why, when acting improperly according to such impressions, it should not be made to act properly by the same mode, namely, by impression. The cure of inflammation is resolution, and an attempt towards it, when in the adhesive state (for this is intended to prevent suppuration taking place), must be in general made only under the following circumstances, namely, when inflammation arises constitutionally, or from disease of the part. In cases of accident where there is no exposure, as also where there is, but that exposure is removed in time by bringing the parts into contact, and where the life of the parts has not been destroyed, in all such cases we find that resolution will readily take place. It is commonly supposed that there are a great many local inflammations which should not be resolved. An inflammation arising from a preceding indisposition in the constitution, commonly called critical, has always been classed amongst those which are not to be resolved ; it has been insisted on that the inflammation should rather be encouraged, and suppuration produced. But in such treatment it is always under the idea that the inflammation is in such parts as will readily admit of cure when suppuration takes place; for if the disease is otherwise situated, the cure of the constitution by suppuration will be a mode of cure which will reflect back another disease on the constitution, under which it. will sink; therefore resolution in such situations should, if possible, be brought about. Many deep-seated inflammations, if allowed to suppurate, will, of themselves, most certainly kill: gout also, in the head or stomach, should always be resolved, and left to settle in some other part less connected with life. If inflammation is really a concentration of the constitutional complaint, and if, by not allowing it to rest there, the same disposition would really be diffused over the whole animal again, and would be liable to affect some other more important part, it would certainly be better to encourage it when in a proper part. Still it does not appear necessary that it should suppurate, for suppuration is only a consequence of inflammation; not an immediate effect of the original constitutional disease, but a secondary one. As suppuration, therefore, is only a thing superadded, and as we shall generally find that inflammation subsides as suppuration comes on, I see no reason why inflammation should not in the present case as well subside by resolution as by suppura- OF ADHESIVE INFLAMMATION. 181 tion. It may, however, be supposed, that as this suppuration is not a natural or immediate effect of the disease, yet as it is a continued local action, that it is capable of diverting the disease to the part. I hardly know an instance where inflammation from violence may not with propriety be resolved, and prevented from going into suppuration, except where it relieves the constitution from any prior disease. Thus, Mr. Foote was cured of a violent pain in his head by amputation of his leg; but he afterwards died with a different complaint in his head. Might not the first diseased action in the head be altered in this case, and an action of a different kind induced, which proceeded to the degree of effecting his death 1 Of the Resolution of Inflammation by Constitutional means.—If the inflammation is of the true adhesive kind, the only thing to be done is to lessen everything that has a tendency to keep it up, because we know of no method that will entirely quiet or remove the inflammatory disposition, or mode of action ;* there is no specific against inflammation that we are acquainted with. Whatever will lessen the power or disposition will lessen the effect. There appear to be three methods which tend to remove inflammation : first, by weakening; secondly, by producing temporary weakness ; thirdly, by lessening or soothing the irritability. That which absolutely weakens is bleeding, purging, quietude, and low diet. The temporary weakness is produced by sickness at the stomach, faintness, &c. The soothing effect may be produced by sedatives, antispasmodics, &c, such as many sudorifics, anodynes, &c. The first will have the greatest, most immediate, and most lasting effects; the second and third act as auxiliaries; the second probably will come nearest to lessening the cause while the other will assist so far as irritation is a cause ; they should go hand in hand, for wherever we lessen the power we should at the same time lessen the disposition for action. But neither bleeding, sickness, nor purging can possibly lessen the original inflammatory disposition :f by lessening the power of action of any disposition you only lessen or protract the effects, which, however, will be of singular service, as less mischief will be done, and will often give the disposition time to wear itself out. Bleeding, then, at first may be necessary; but this must be done with some restriction. If inflammation arises from real powers, then bleeding freely is absolutely necessary; but if from too great action of weak parts, bleeding should be no more than what will just lessen the violence of the blood's motion, or remove the feeling

* [Mercury and colchicum are perhaps exceptions to this observation ; at least they certainly subdue inflammatory action with extraordinary rapidity in many cases.] \ [In this instance the author has allowed reasoning and hypothesis to usurp the place of observation and fact. It is certainly not uncommon to witness the almost complete destruction of an inflammatory attack by a single copious venesection.] 16 182 HUNTER'S PRINCIPLES OF SURGERY. in the part inflamed of too much to do. The quantity, therefore, must be according to the symptoms and other circumstances, that is, according to the visible indications. The indication for bleeding is, first, according to the violence of the inflammation, joined with the strength of the constitution : secondly, according to the disposition to form blood ; thirdly, whether the disease is in a vital part: fourthly, its situation, whether near the heart or not; fifthly, according to the duration and the extent to which it has affected the constitution.* With respect to the first kind, in which the constitution is strong and the inflammation is violent, bleeding largely is proper, and in many cases bleeding near the part will answer better than from the general habit; less may be taken away in this way with an equal effect on the part inflamed, and of course with less effect on the constitution, as bleeding from the temporal artery, or the jugular vein, for complaints of the brain, or cupping or applying leeches near the part, as, for example, to the temples in inflammation of the eyes. The same mode of practice is to be followed with regard to the second, third, fourth, and fifth. It seldom happens that one bleeding will be sufficient in a considerable inflammation. The first blood taken affords a symptom of the disease; if it is buffy, thick, and considerably cupped, future bleedings may be used with less caution. On the other hand, there may be indications for bleeding sparingly; first, from there being too much action with weakened power; secondly, from a disposition to form little blood; thirdly, from the part being far from the source of the circulation. A gentleman had a violent inflammation of the eye; the blood was sizy, but though sizy the coat was exceedingly tender, and so slight as not to bear its own weight when raised up. He was blooded plentifully several times without any good. Here was not, then, much power, the blood putting on the sizy appearance in consequence of there being increased action in the vessels of this part of the body.

* [The propriety of blood-letting is indicated by many other circumstances besides those pointed out in the text. I shall only mention three of these at present : the first arises from the structure of the part affected. Thus, serous and fibrous membranes require and bear venesection to an extent which would be perfectly unwarrantable in regard to mucous membranes. The second arises from the probable demands which will be made on the constitution during the future progress of the case. It would be extremely imprudent, for example, to bleed a patient with a severe compound fracture to the same extent which would be perfectly justifiable in inflammation of the eye. The third is derived from the act of venesection itself, as whether the blood flows freely and the state of syncope is easily induced ; for it has been justly remarked that those inflammations which most require venesection support the constitution under considerable losses of blood, and enable it to bear them much more easily than it could have done in a state of health. In most cases of acute inflammation it is advisable to take such quantities of blood at first as shall make a decided impression on the constitution ; one effectual bleeding being of infinitely more service in checking the disease than a number of successive bleedings to a smaller amount, at the same time that the powers of the general system are much less reduced.] OF ADHESIVE INFLAMMATION. 183 A lady with inflammation of the tonsils was blooded; the blood was sizy, but loose; and after three bleedings the blood became so loose that the bark was given, which did service. The disorder returned again, and the same mode was used; the blood was sizy only in the first bleeding; the bark was obliged to be again given. In such cases bleeding is very seldom necessary. Where it is necessary, it should be as near the part as possible, in order that it may have the greatest effect on the part with the least damage to the constitution- If local bleeding be used, leeches will answer best, because but little inflammation follows their bite;* however, this can only be put in practice in inflammations which are pretty much external. In many cases we cannot take it immediately from the part, and must be content to go as near as we can, as in bleeding from the temporal artery or jugular vein, in affections of the head. Sometimes of course even this will be impossible, as in inflammations of the liver and stomach. Too much action writh small powers may often, if not always, be classed with the irritable, and bleeding here should be performed with very great caution. When inflammation is far from the source of the circulation the same precaution is hardly necessary, as in general it can be taken away from the part. We cannot depend on sizy blood alone as a proof of the propriety of repeating the bleeding; we must take into consideration also the strength of action. The pulse is a great indication for bleeding in inflammation, but is not always to be relied on. In inflammations that are visible, the knowledge of the kind of inflammation is in some degree ascertained, in which cases it has been supposed that we go on surer grounds in our indications for bleeding. But all inflammations are not visible: therefore we require some other criterion. If we could ascertain the pulse peculiar to certain appearances in visible inflammations, and were sure that universally the same pulse attended such appearances, we should then suppose we had the true indicative criterion to go by, and be able to apply it to invisible inflammations, and judge of these by the pulse. But when we consider that the same kind of inflammations in every part of the body will not produce the same kind of pulse, but very different pulses not according to the inflammation, but according to the nature of the parts inflamed, and many of these parts are invisible, we see that we at once lose the criterion of the pulse as a guide. There may be every symptom of inflammation and the pulse be soft, and not quicker than usual, and yet the blood when taken away will be sizy and cupped. A lady had this kind of pulse (soft and not quick), and at the same time had a violent cough, with tightness of the chest and stitches in the side; bleeding was ordered, when the blood was found sizy, &c.; nor did the illness subside till the sixth bleeding. A hard quick pulse is generally an indication for bleeding, being * [Cupping will generally be found more effectual where it is practicable, on account of the blood being more rapidly removed.] 184 HUNTER'S PRINCIPLES OF SURGERY. frequently accompanied with sizy blood ; but even these signs are not always to be depended on as furnishing a criterion. The kind of blood is of consequence to be known, for although it should be sizy, if it is not firm in its texture, but lies squat in the dish, bleeding must be performed very sparingly. As the pulse simply, independently of all other considerations, is not an absolute criterion to go by, and as a sizy and strong coagulum is only an afterproof, let us see if there are any collateral circumstances that can throw some light on this subject, so as to enable us to judge, c\ priori, whether it is right to bleed where the pulse does not of itself indicate it. When speaking of inflammation of various parts, I took notice of the pulse peculiar to each part, which I may now be allowed to repeat. First, I observed in inflammation of parts not vital, or such as the stomach did not sympathize with, that if there was great power and not much irritability, the pulse was full, frequent, and hard. Secondly, on the contrary, in inflammations of the same parts, if the constitution was weak, irritable, &c, that then the pulse was small, frequent and hard, although, perhaps, not so much so as when-, thirdly, the inflammation is in a vital part, as the stomach or intestines, or some part with which the stomach readily sympathizes ; then the pulse is quick, small, and hard. Now in the first of these dispositions bleeding is absolutely necessary; but in the second, where the pulse is small and frequent, bleeding should be performed with great caution : though the person may be of strong constitution, yet in inflammations of these parts the constitution appears to be more irritable, and to have a greater sense of weakness. We should bleed to two or three ounces by way of trial, which could do no harm. The urine will throw some light on the disease; if high-coloured, and not much in quantity, it may be presumed, with the other symptoms, that bleeding will be of singular service; but if pale and copious, though the other indications may be strong for bleeding, it ma)r be necessary to do it with caution. Bleeding, however, is a remedy of so much importance that it should be employed in all cases with great caution; yet not more than appears really necessary. I cannot perceive why bleeding should have such an effect on inflammation as it often has. We cannot account for it simply on the mechanical principle of lessening the quantity of blood, because this can never remove the cause of inflammation. Medicines.—Medicines which have the power of producing sickness lessen the powers of life universally, because every part of the body sympathizes with the stomach; and when they are intended to produce this effect they should not be given in doses sufficient to produce anything more than sickness, for the act of vomiting is rather a counteraction to that effect, and I believe has rather the effect of rousing, as few are so weak as not to be able to bear sickness. Purges have been much recommended, under the idea that there were humours to be carried off; such practice answers best OF ADHESIVE INFLAMMATION. 185 in the cases in which bleeding is useful. In irritable habits, where inflammation becomes more diffused, greater caution is necessary, as nothing tends to weaken the habit more. A single purge has been known to produce death in dropsy. In such cases bark may be required to bring the constitution into a proper state, either for resolution or suppuration, by increasing the powers and diminishing the action; and thebaica may be a good assistant as a soother or sedative with the bark. Modes of Resolution by external applications—Whether we have any external applications which have really a tendency to resolve an inflammatory disposition, is not well ascertained. We are in possession of many that can weaken, so as to lessen the powers (most of which appear to be of the soothing kind), and thus lessen the action, though the cause may still exist; by which means the effects are lessened, and the inflammation is either cured or protracted, until the disposition wears itself out. Perhaps cold is one of the greatest weakeners, but it should not be used too freely, as it may produce a worse disease, which is indolence. Lead is supposed to have considerable effects in this way; but I believe much more is ascribed to it than it deserves. Its properties appear to be to lessen the powers, and therefore it should not be used except when the powers are too strong. Applications to weaken should not be applied to irritable parts ; on the contrary, the parts should be strengthened, which can only be done through the constitution. Whatever power external applications possess, they must act in one of four ways: first, which is the immediate or truly local; second, by repulsion; third, by revulsion and derivation; fourth, by sympathy, which is probably the same principle in the animal economy as revulsion and derivation. The first, or local effect, may be of two kinds: 1st, simply such as is an antidote to the action of the part, as cold, sedatives ; 2d, such as destroys the first irritation, by exciting a second. This is most applicable to specific diseases, as the action of mercury in a venereal sore: but all specific diseases will not allow of it; a gonorrhoea in a scrofulous habit is an instance of this. In some cutaneous affections this mode of cure is very useful. Sedatives are less useful as local applications than counter-irritants, but both of them may have another effect, viz., repulsion or derivation, which must be from a constitutional affection, such as I have called an act of the constitution, as in gout. If the constitution is determined toiiave a local complaint, by which she throws off a constitutional disposition, then these revulsions do not rid the constitution of the disposition. It is difficult to say what will merely repel and what will cure. Repulsion, however, is a cure of the part, whatever effect it may have on the constitution. Surgeons were formerly greatly afraid respecting repulsion. They were even afraid ot curing a gonorrhoea, lest they should drive it back into the constitution and produce a pox; but they did not consider that it does not arise from the constitution, and has nothing to do with it. 16* 186 HUNTER'S PRINCIPLES OF SURGERY. Revulsion and derivation appear to me to depend on the same principle in the constitution as sympathy, and, like the latter, have the greatest effect in habits which are irritable or nervous, and in diseases which are nervous, as cramp; not in such as change the structure of parts. I knew a nervous girl cured of pain in one arm by rubbing the other. These terms were used under the idea of removing humours by inviting them from other parts, as making an issue to remove eruptions. They probably act by causing an irritation in one part to cease when an irritation in another is excited; and this latter may be made greater than the original one though in a part less dangerous, and where it can be more easily cured, as burning the ear cures the tooth-ache; vomiting, the swelled testicle; blisters, pleurisy, &c. In some of these, as the vomiting to cure the testicle, no new disease tis excited, but only the action of the part. The cures performed by these modes are in many cases preferable to those by means of local applications, and they will succeed where the others fail; thus vomiting will cure hernia humoralis, when other applications have had no effect. The cure by revulsion, or sympathy, is in some respects the reverse of that by derivation, yet it is probably from the same consent of parts, but from a different action. In these a remedy is applied to a sound part to cure a diseased, which is either contiguous, continuous, or remote, and the action is either similar or dissimilar. The cure of continuous parts by similar sympathy is by the application of such remedies as we suppose would cure if applied to the part. That of remote parts by dissimilar modes of action, is by stimulating a part in such a way as that the sympathy shall act in the same way, and yet the action in the diseased part be not at all similar to that in the sound part: suppose, for instance, a part in any mode of action, a medicine applied to it would increase that action, but by applying it to another part it will remove the first. The contiguous is different from the two former, and can only be applied to surfaces, as a blister to the scalp to remove headache. These may be either stimulating or soothing, or specific. Treatment of adhesive Inflammation when Suppuration must take place.—The treatment must, in some measure, be the same as in the foregoing in accidents where the powers are very great, and the inflammation violent, namely, bleeding, purging, sickness, &c.; but when the constitution is irritable, bark, &c, as before directed. In cases where there is considerable sympathy, sudorifics, as Dover's powder, seem desirable, as they tend to keep up the harmony between the skin and the stomach. Opium in peculiar constitutions increases irritability; but in others, where there is not this peculiarity, it is highly useful in soothing and diminishing irritability. Different applications have been made to the inflamed parts, as fomentation, washes, poultices, &c. The mode of applying heat and moisture by fomentation appears more efficacious than in the form of a fluid ; it certainly gives ease at the time of the application, but the symptoms generally recur between the times of using it, and with nearly the same violence. How far the application of a OF SUPPURATIVE INFLAMMATION, ETC. 187 medicine for fifteen minutes out of the twenty-four hours does good I hardly know. Washes are fluid applications, and are more commonly used to inflamed internal surfaces than to the common integuments. I am afraid we are not much acquainted with their true specific virtues, the use of them being very vague. For inflammation of the eyes we use astringents, as alum, vitriol, &c. For inflammations of the throat we gargle with port wine, vinegar, &c.; yet how absurd it would be, in the opinion of any surgeon, to use the latter applications to the eyes; and yet if the two inflammations are the same I do not see why we should not use the same remedies to both parts. These, like the former, have only temporary effects. Poultices are constant applications, and may be either simple or medicated; their effect is greatest locally, but it extends likewise to surrounding parts, by sympathy. They may be medicated with lead, opium, &c. Simple poultices are the best application where we have no particular object in view. CHAPTER XIV.

OF SUPPURATIVE AND ULCERATIVE INFLAMMATION ; GRANULATION, SKINNING, HECTIC FEVER, AND DISSOLUTION.

Suppurative inflammation ;—difficulty of tracing the chain of causes leading to it;—not arising from the access of air ;—nor from external violence ;—occurs most readily in canals.—Peculiar pain attending it;—rigor;—diminution of the inflammation.—Cure of suppurated parts ;—abstraction of matter by absorption, or by external opening;—granulation;—cicatrization.—Of pus;—its formation ;—gradual changes from lymph to pus;—breach of substance not necessary to its existence ;—erroneous notions of its formation and uses.—Of absorption of the whole or parts of the body, in consequence of disease.—Interstitial and progressive absorption.—Interstitial of two kinds;—1st, wasting; —2d, complete removal.—Importance of the latter;—and of progressive absorption.—The two sometimes mixed.—New parts most subject to be removed. __Causes which render parts liable to absorption.—Relaxing process of the skin over an abscess.—Absorption with or without suppuration ;—Ulceration ; —progressive and interstitial absorption combined ;—almost always accompanied by inflammation ;—seldom affects the constitution.—Whitlow.—Granulation ;—not always attended with suppuration ;—does not appear till abscess has been opened ;—arises on one surface ;—nature and structure of granulations ;—colour an index of the state of the parts and constitution ;—contraction of granulations;—followed by cicatrization;—an assistance to this process.—Of skinning.—New skin generally arising from old skin;—economy of nature in forming new skin.—Hectic ;—when arising; causes numerous; —symptoms ;—erroneous notion of cause.—Treatment;—incurable ;—when from local disease in removeable parts, they are to be removed.—Dissolution, definition of the term;—when occurring;—symptoms ;—incurable.

When an inflammation exceeds the adhesive state, and has got beyond the power of resolution, and when the adhesive has set 188 HUNTER'S PRINCIPLES OF SURGERY. bounds to the suppurative inflammation, the suppurative begins; or in internal surfaces, where the adhesive cannot take place, the suppurative begins. The irritation which is the immediate cause of suppuration is the same, from whatever cause it may have been produced: it is a similar process, going through the same stages, whether it takes its rise from external violence, or from the constitution, or from disposition for disease in a part, if all other circumstances are equal. It is very difficult to give a true and clear idea of the whole chain of causes which lead to suppuration. Irritation simply is not always sufficient; it often only brings on the adhesive inflammation. Violence done to a part is one of the great causes of suppuration, but this alone is not sufficient: it must be with a prevention of union by the first intention, or by adhesive inflammation; it must be attended with death in the part, as in bruises. The application of air to internal surfaces has generally been assigned as a cause of inflammation, when it happened in consequence of destruction of a part; but air has certainly no such effect, for a stimulus would arise from a wound were it even contained in a vacuum; nor does it get to the parts forming circumscribed abscesses, which yet suppurate, in consequence of inflammation, as readily as exposed surfaces. In many cases of emphysema, where the air is diffused over the whole body, we have no such effect, excepting there is produced an exposure of some internal surface for the air to make its escape by, and then the wound inflames. In birds we find the cells in their bones communicating with the lungs, so that they have at all times more or less air in them, although they never inflame ; but if these are exposed by a wound, the stimulus of imperfection is given, and inflammation begins, and suppuration may succeed. The same observation is applicable to a wound made in the abdomen of a fowl, for there the wound inflames and unites the intestines, to make the cavity perfect again; but if the union is not allowed, to take place, more or less of the abdomen will inflame and suppurate. How should we account also for suppuration taking place in the nose during catarrh, since it is not more exposed to air then than at other times 1 Air, therefore, is not the cause of suppuration. We are at a loss to say, with regard to spontaneous inflammation, whether it is a disease in which the constitution will be injured, or whether it is a salutary process in which nature is endeavouring to relieve herself; and it is evident that the same action may arise from different causes. Suppuration does not depend on the violence of the inflammation : for that circumstance, simply considered, rather tends to produce mortification; and we see that in gout, which does not suppurate, there often is more violent inflammation than in many other cases that do : and in true scrofula we have suppuration without any visible inflammation: so that this does not seem essential to suppuration. Although wre find that inflammation and suppuration from injury are very violent, yet that which occurs spontaneously generally OF SUPPURATIVE INFLAMMATION, ETC. 1Q9 exceeds it in violence. In inflammations of the breasts in women and of the testicles in men, the quicker the inflammation proceeds the better; for where it is slow it gives the idea of specific inflammation, as this generally proceeds slower than simple inflammation. Suppuration takes place more readily from the surface of canals than in either the cellular or investing membranes ; the same degree of inflammation which will produce suppurative in the first mentioned parts will only produce adhesive in the latter. If a bougie be introduced into the urethra, it may produce suppuration; but if introduced into the tunica vaginalis or abdomen, it will only give a disposition for adhesions. Symptoms of suppurative inflammation.—The sensations arising from a disease generally convey some idea of its nature. Some diseases give what is called a heavy, a dull, or a gnawing pain,&c: but the suppurative inflammation gives as much as possible the idea of simple pain, without having relation to any other mode of sensation ; this pain is increased at the time of the dilatation of the arteries with the sensation called throbbing. The part now becomes more swelled by the greater dilatation of the vessels and a greater quantity of extravasated fluid being poured out, and the scarlet colour increases from the admission of red globules into vessels, not naturally conveying them, and the formation of new vessels, and an cedematous appearance, like that in erysipelas, takes place. One, two, or three parts of the inflammation lose the power of resolution, and take on exactly the same disposition with that of exposed surfaces, or a surface in contact with an extraneous body. If it is in the cellular membrane that this disposition takes place, or in the investing membrane of circumscribed cavities, the vessels now begin to alter their disposition and mode of action, and continue changing till they bring themselves to that state which fits them to form matter. But as this change does not take place all at once, some parts may for some time continue to discharge coagulable lymph, as in the adhesive state, whilst those parts which have taken on the suppurative action pour out matter: and hence, if the tumour be now opened, it will be found to contain both matter and coagulable lymph: in which state it has always been imagined that the matter had not arrived at a state of ripeness by those who supposed its purulence to depend on its confinement and stay. It would appear, from matter forming from the investing membranes of internal cavities and from mucous surfaces, that matter may be formed without any breach of surface. There is a certain period in inflammation when suppuration begins, and which is discovered by new symptoms, as shivering, &c.; and though the change is pretty quick, time must be allowed for the vessels to be fitted for the suppurative state. Ihe effect ot inflammation seems to be the producing the suppurative disposition, or that state of parts which disposes them to secrete pus: in doing this, inflammation seems to be carried to such a length as to destroythat state of parts on which itself depends; the consequence of which is that they lose the inflammatory and come into that disposition 190 HUNTER'S PRINCIPLES OF SURGERY. which fits them for throwing out matter. That the suppurative is very different from the adhesive inflammation is plain from this, that if a wound in a suppurative state, yielding good matter, has by irritation of any kind the adhesive inflammation produced in it to any degree, the discharge lessens, and the wound puts on appearances very different from what it had before. It seems a fixed and useful law in the animal economy, that when inflammation has gone to the length of destroying the natural functions of parts, so as to prevent their returning by a retrograde motion to that state from which they set out, suppuration should come on to give them a disposition for a second mode of cure. Treatment of Suppuration.—Suppuration may sometimes be removed by producing action in other parts: thus, I have seen a bubo cured by a vomit, and similar effects are producible on scrofulous tumours. When suppuration cannot be stopped or resolved, in most cases it is to be hurried on towards the skin, which generally is the first step taken by surgeons. How far suppuration can be increased by medicines or applications I do not know, but attempts are generally made ; hence we have, I think, in the pharmacopoeia, (though I do not read many books,) suppurating cataplasms, maturating, &c, but I doubt if they have considerable effect in this way, for the same applications applied to a sore would hardly increase the discharge of that sore. However, in cases where the parts are indolent, and hardly admit of suppuration, by stimulating the skin more salutary inflammation may be produced, and of course quicker suppuration; but with true suppuration, preceded by inflammation, it is I believe hardly necessary to do anything with respect to the suppuration itself. Nevertheless it has perhaps been found by experience that these applications tend to bring matter faster to the skin, even in the rapid suppurations; only, however, in those cases where the inner surface of the abscess is within the influence of the skin. This effect, too, may arise from another mode of action being produced than that of quicker suppuration, which is the hastening of an ulceration. Poultices of bread and milk are commonly used to inflamed parts when suppuration is known to have taken place : this application can have no effect, except that of lessening the inflammation, or rather making the skin easy.* Of suppuration without inflammation.—I have hinted that thickening of parts took place sometimes without inflammation, and also that the suppurative inflammation might take place without being preceded by the adhesive. Many indolent tumours, slow swellings of the joints, swellings in the lymphatic glands, tubercles in the luno-s, and swellings in many parts of the body, are of the first kind, namely, thickening without visible inflammation ; and the contents

* [The immediate effects of poultices and fomentations to inflamed parts are, 1st, to soothe the pain and irritation; 2d, to augment the local perspiration ; and, 3d, to diminish the tension. The addition of sedatives and narcotics certainly increases their soothing effects, and their continued application certainly promotes the suppurative process.] OF SUPPURATIVE INFLAMMATION, ETC. of some kind of encysted tumours, the matter of many scrofulous suppurations, as in the lymphatic glands, and in the joints of the foot and hand, for instance, and in the hip-joint, called hip-cases, of the loins, called lumbar abscess, the suppuration of tubercles in the lungs and in many other parts of the body, all exhibit the formation of matter without any previous visible inflammation. They come on insensibly, the first symptom being a swelling in consequence of the thickening, (which is not the case in inflammation, for there sensation is the first symptom,) and this swelling is increased by the formation of matter.* The nature of the matter is another distinguishing mark between suppuration in consequence of inflammation and that without it, the latter being generally composed of a curdly substance mixed with matter. The curdly matter is, we may suppose, the coagulable lymph deprived of serum, the thinner part is true pus, having the globules and specific properties of pus, and is often as thick as the common pus formed in consequence of inflammation. All parts which form pus of any kind, whether in consequence of inflammation or otherwise, must go through similar processes to produce the ultimate effect or cure. The first step, in either case, is the evacuation of this matter, for till that is effected nature cannot take means towards a cure; the second step is granulation; the third, cicatrization. There are three modes of doing the first; one is the absorption of matter, which is very common in the scrofulous kind, but not in those suppurations which are the consequences of inflammation, and which produces no alteration of the part except the gradually creeping into a sound state; the other modes of discharging this matter are, either opening the abscess, to allow it to pass out, or allowing ulceration to take place on the inside to produce its escape; which process, in the present case, having peculiarities different from those arising from inflammation, it is necessary to explain still further. Ulceration in consequence of suppuration arising from inflam mation, is very rapid, especially if the suppuration is very rapid; but ulceration in consequence of suppuration not the effect of inflammation, is extremely slow: it may remain months or even years before the parts give way. When an abscess in consequence of inflammation is opened, it immediately proceeds towards a cure, and perhaps may have gone

* [Those singular deposits of purulent matter which occur in the joints, the serous cavities, the viscera, and the cellular membrane, during the progress of phlebitis and secondary inflammations, are examples of the same kind. I have, on several occasions, found all the principal joints of the body filled with an apparently healthy pus, although during life there were no symptoms of inflammation, nor after death any indications of increased vascularity. The question, therefore arises. Does suppuration ever occur independently of inflammation 1 I think it does. The formation of cartilage antecedently to that of bone is a parallel case, and yet instances every now and then occur in which ossific depositions are formed independently of this condition.] 192 HUNTER'S PRINCIPLES OF SURGERY. some steps towards a cure before the opening. As inflammation lessens, suppuration becomes still more perfect, granulations begin to form, &c. But when an abscess not preceded by the common inflammation is opened, a very different process is first to take place; the consequence is, that inflammation now takes place over the whole cavity of the abscess, which afterwards produces perfect matter, like that produced when inflammation is the original disease. However, it sometimes happens that they inflame before they are opened, in consequence of the matter distending the cavity acting like an extraneous body, not in consequence of the cause of suppuration. I have seen white swellings of the knee inflame before they were opened, then ulceration took place, and the pus was brought soon to the skin, though before it had been for months without producing the least tendency to ulceration, and of course none to inflammation; but the confinement of matter became the cause of inflammation. The inflammation and new suppuration taking place in consequence of an opening into these abscesses, is exactly similar to those inflammations and suppurations which take place in consequence of an opening made into internal cavities; and it is extraordinary that often upon opening these swellings, inflammation, fever, nay death, shall follow, but if suffered to break of themselves no such effect is produced. Of Pus.—The immediate effect of the modes of action above described is the formation of matter commonly termed pus. This matter is very different from what was discharged during the adhesive stage of inflammation, and also very different from the common secretion of internal canals : yet when these surfaces form pus it is probable they are formed by the same vessels; if so, their mode of action must be greatly altered. In suppuration of the cellular membrane or of circumscribed cavities their vessels are but little changed at the commencement of the suppurative disposition, so that they still retain much of the form they aqcuired by the first stage. The discharge is at the beginning little more than coagulable lymph mixed with some serum ; this is scarce different from the discharge in the adhesive stage of the inflammations; but as the inflammatory disposition subsides, a new disposition is every instant altering these vessels to the suppurative stage; the discharge is also varying constantly from a species of extravasation to the new-formed matter peculiar to suppuration. The matter removes further and further from the nature of blood, losing the yellowish or greenish hue, and becoming white, and more viscid and creamy. _ By the formation of this new substance, the coagulable lymph, which was extravasated in the adhesive state, and adhered to the sides of the cells, either on cut surfaces, as wounds, or on the walls of abscesses, is pushed off, and if there is a cavity, is pushed into it, so that wTe should find in the cavity both coagulable lymph and pus; or, if on a cut surface, it is thrown off, and is generally removed, along with extravasated blood, &c, with the dressings. OF SUPPURATIVE INFLAMMATION, ETC. 193 This is the process which takes place in the first formation of pus in an abscess, or from the surface of fresh wounds. On the internal surface of canals the parts are not obliged to go through all these steps; they run into suppuration almost instantaneously. Mode of Formation of Pus.—Pus is formed by some change, decomposition, or separation which the blood undergoes in its passage out of the vessels. To carry on this process, either a new and peculiar structure of vessels must be formed, or a new disposition or mode of action of the old must take place. This new structure of vessels, or new disposition of vessels, I shall call glandular, and consider pus as a secretion.* Dissolution of the living solids of an animal body into pus, and that the pus already formed has a power of occasioning their further dissolution, is an old opinion, and is still the opinion of many. But if this idea were just, no sore which discharges matter would be exempted from continual dissolution; and I think it must appear inconsistent that matter which was probably intended for salutary purposes should be a means of destroying the very parts which produced it. The circumstance of internal circumscribed cavities, as the abdomen, thorax, &c, forming pus, and where they might often have seen pints of matter, v/ithout any breach in the solids to produce it, (which is proved beyond controversy to lake place,) should have taught them better; and the prevalence of this idea certainly shows a barrenness of knowledge and observation. Such an idea might be forgiven when it was thought that the discharge in gonorrhoea arose from an ulcer; but now that it is known that there is no ulcer in the urethra, it can only continue from mere stupidity. The moderns have been more ridiculous still: they have put dead matter into pus, and have thought that it has been formed into pus, and have thence inferred opinions similar with the former. In this case they have been putting dead and living animal matter on the same footing. But what is still further, they might have seen that extraneous matter cannot be formed into pus, by observing that in wounds, and in suppuration with extravasation, blood and pus are found separately in the same cavity, and that in extravasation of blood in sound parts no pus is produced. In abscesses from violence and erysipelas they might have seen sloughs of dead cellular membrane, hanging like wet tow, and not melting down into pus, although exposed to the action of matter for a long time. The same observation holds good with regard to dead bones, when exposed to the action of pus; besides, if, in consequence of the decomposition of

* [Delpech endeavoured to prove that pus was always secreted by a new membrane {membrane puogenique) developed by inflammation; an opinion which received some colour of support from the appearance of cysts in old abscesses. Nothing, however, is more common than to see suppuration from mucous and serous surfaces, where no trace of any such membrane is discoverable.] 17 194 HUNTER'S PRINCIPLES OF SURGERY.

these parts, some of their parts are mixed with pus, it is altered in its properties, thereby attaining a very ill smell. But if there is loss of substance in a dead piece of bone, for instance, it is produced by absorption; in proof of which we see that the loss is on that side where it unites to the sound parts, and where alone the absorbents can act. The chemists found no difficulty in explaining the formation of pus, and this they supposed took place by fermentation. But fermentation necessarily implies that there should be something to ferment; and, according to this idea, there are three effects which contradict the notion of fermentation flatly. First, internal canals, where mucus only was formed, take on the formation of pus without previous loss of substance or previous fermentation, and they leave off the action in the same way. Secondly, internal cavities take it on without loss of substance. Thirdly, abscesses already formed leave it off. If fermentation wras the cause in the first, what solids enter into the matter discharged 1 for the whole penis could not afford matter enough to form the matter discharged in a gonorrhoea. And how or by what power was the fermentation commenced? and how should it ever cease? for there is the same surface secreting its mucus whenever the fermentation of pus ceases ? In the second case, what solids were destroyed when fermentation began? by what power is the first particle of this fluid formed in an abscess or sore, before anything exists capable of dissolving solids ? And according to the third, an abscess shall form matter, become stationary, perhaps for months, and at last be absorbed; and what becomes of the ferment during the time it remained stationary ? We may safely, then, discard these notions, and say that pus is formed from the fluids alone, by the action of the living solids. Pus appears to consist, when examined by the microscope, of globular bodies, such as compose cream ;* these may be white, or not so, as we find glass appears white when powdered, though not really so. The globules swim in serum, or a fluid like serum, and most probably there is a little coagulable lymph mixed with it. The proportion that those white globules bear to the other parts depends on the health of the parts which form it; and when in larger proportion, the matter is thicker and whiter, and is called good pus, that is, the

* [These bodies were found by Dr. Hodokin to be irregular in size and figure, and to have no resemblance to those of the blood ; from which Dr. Babington has inferred the probability that pus consists merely of lymph, in a minute state of division, suspended in serum. The existence of globules gives to this fluid an iridescent appearance when viewed between two plates of glass, which was proposed by the late Dr. Young as a test of the presence of this matter in doubtful cases, and is still considered the best which we possess. Another test, derived from the facility with which pus is diffused through water, and afterwards subsides, is applicable to a great many cases, and is much to be preferred to any of those which depend on the reaction of chemical agents. The fact however is, that pus and mucus insensibly merge in one another, which renders the distinction between them in transitu impossible.] OF SUPPURATIVE INFLAMMATION, ETC. solids that produced it are in health, for these appearances in matter are no more than the consequences of certain salutary processes which are going on in the solids, the effect of which is to produce a disposition on which both suppuration and granulation depend. Pus has a sweetish mawkish taste, as is known when it is formed in the mouth, and it coagulates by heat. This is the same, whether from an irritated natural surface, as the membrane of the nose and other outlets and canals, or from an ulcerated surface. These discharges from canals or outlets have been termed mucus, and not pus; and the surfaces yielding these discharges have been termed mucous membranes. A test has been recommended for distinguishing these when their appearances have been so exactly similar as to afford no visible difference, and when, as I observe, they are in fact one and the same fluid. This test was the chemical solution of the fluid in menstrua, and its precipitation therefrom, a proposal which was unphilosophical on the very face of it, and which I treated from the first as absurd. I did conceive that all animal substances when in solution, either in acids or alkalies, were in the same state, and that the precipitation from them would be the same. But as it was so slrongly asserted, and supported by experiments said to have been made, I, to satisfy myself, made several experiments with animal matter, both solid and fluid; these I dissolved in different acids, vitriolic, muriatic, &c, and made precipitates with several alkalies, both fixed and volatile, but all these precipitates appeared the same, even when examined with the microscope, exhibiting universally a flaky appearance. The quality of the matter always depends on the nature of the part secreting it: whatever specific quality the partis affected with, the pus will possess the same; hence we have venereal matter from venereal sores, cancerous matter from cancerous sores, &c.; but though it takes on these qualities when the part yielding it is so affected, yet it does not derive these qualities from the constitution if it is so affected, unless that part is also affected. A circumstance which serves to show that the part which yields it is of the same nature with the matter produced, is that it does not prove an irritator to the surface yielding it, though it may to another; hence no suppurating surface can be kept up by its own matter. The gonorrhoea, small-pox, &c, curing themselves is a proof of this, for were not this the case we should have constant pain from the irritation and much more difficulty in the cure. We do, indeed, sometimes find that pus will irritate its own surface; but this may be the effect of some extraneous matter, as blood, &c, in the pus; the intestines will sometimes produce a discharge which stimulates them very considerably; but this may be secreted by the diseased surface, and prove an irritator to the sound part of the canal only. What I have hitherto said refers to natural pus only; but when a specific nature is added, then the secretion is altered. The first alteration is a greater quantity of serum and salts, producing a thinner discharge, called sanies; this discharge has sometimes 196 HUNTER'S PRINCIPLES OF SURGERY. appeared to affect the solids, and has thence been called corrosive, a property which it does not possess,* the parts only receding from the irritation; and where this is the case, perhaps, the decomposition and new combination necessary to the formation of pus is not perfect, in consequence of the vessels having lost that structure which is proper for the secretion of pus; and this is probably the case, as healthy granulations are not produced when such matter is secreted. By what particular organization matter is produced we can no more determine than we can the nature of any other glandular organization. Pus appears to have a greater tendency to putrescency than the other secretions have, but I do not think this is in the degree that has been supposed. It is brought into a putrescent state by circumstances independently of the pus itself. If the air is admitted to it by a small opening in an abscess, or it is placed near the intestinal fasces, or some parts of the solids which have sloughed, then it will be fetid; or if any dead blood, as in recent sores, is mixed with it, it is fetid ; but if perfectly confined in an abscess it is always sweet, and will be a long time in putrefying. In erysipelatous inflammation, however, where there is an internal inflammation, there will be putrefaction; but this is probably from the solids themselves first putrefying. Hence we find, in most cases of specific disease, that the pus is offensive, because blood is mixed with it. Where there is dead bone also pus becomes very offensive. The final intention of this secretion of matter is not, I believe, yet understood. Some say it is carrying off humours from the constitution, or that it is a constitutional disease changed into a local one, and so discharged, or thrown out of the body, either in the form of pus, or with it, as in those cases called critical abscess. Or it is presumed to carry off local complaints from other parts, by way of derivation or revulsion; hence sores or issues are made in sound parts to allow other sores to be dried up. But I am apt to believe that we are not yet well, or at all, perhaps, acquainted with its uses. We might naturally suspect that it was on the surfaces of sores to keep them moist, but thi§ will not account for its formation on internal surfaces. Absorption of whole parts in consequence of Disease.—The immediate effects of absorption of the body in consequence of disease may be said to be of two kinds. The first is only a wasting of a part, or the whole, without any breach in the structure or form, and

* [Pus very often corrodes the external parts. There seems also the greatest reason for believing that the presence of pus is highly deleterious in several forms of inflammation, as carbuncle, diffuse cellular inflammation, erysipelas aedematodes, inflammation arising from the bite of vipers, &c. Unless free and early openings are made in these cases, the inflammation or gangrene extends, apparently from the infiltration of pus, or that diseased secretion which precedes the formation of pus into the unadherent cellular membrane. That the pus, under such circumstances, acquires a highly poisonous quality, is proved by the effects which it produces on the constitution when injected into the veins (See p. 136, note.)] OF SUPPURATIVE INFLAMMATION, ETC. 197 this I call the interstitial absorption; the second consists of the total removal of a part, as if by art, and this is the progressive absorption. The interstitial absorption may be considered in two lights; 1st, where it leaves the part affected still a whole, though wasted; 3d, where it entirely removes it, which latter resembles the natural process by which useless parts are removed, as the thymus gland, the membrana pupillaris, &c. The process of removing entire parts of the body, either by the second interstitial or the progressive absorption, answers very material purposes in the machine. It is by means of the progressive that bones exfoliate and sloughs separate, that pus is brought to the skin, and that while new bones are formed old ones are removed ; and although in these cases the process arises from disease, yet it is somewhat similar to the modelling process in the natural formation of bone. It is this last that removes useless parts, as the alveolar processes when the teeth drop out, or when children are shedding teeth, which allows these to drop out; and it is by these means that ulcers are formed. It is in many cases a substitute for mortification (which is another mode of loss of substance), for it is a degree of strength or vigour superior to that where mortification takes place; and in many cases it finishes what mortification has begun, by separating the mortified part. The progressive is that absorption which begins at one side of a part to be removed, and goes on until the whole is removed, as in spreading ulcers. These two modes, the interstitial and progressive, are generally going on at once, which may be called the mixed. This operation of absorption, like many other processes arising from disease, would often appear to be doing mischief, by destroying parts which are of service, and where no visible good appears to arise from it, as in those cases where the external covering is destroyed by ulcers or sores; but in all cases it must be reduced to necessity, for we may depend upon it that those parts have not the power of support, and it becomes a substitute for mortification. In many cases we shall see both ulceration and mortification going on, ulceration removing those parts which have power to resist death. New-formed parts, or such as cannot be said to form a part ot the original animal, admit more readily of removal than those parts originally formed : probably this arises from the principle of weakness. It is on this principle that all adventitious new matter is more readily absorbed than that matter which forms the substance ot old tumours. . . Remote Causes of Absorption.—The remote causes of absorption are various. The most simple appears to arise from a part's becoming useless, as the thymus gland, the ductus arteriosus, the alveoli alter the teeth drop out, the crystalline lens after couching, the fat ot the body in fever, either inflammatory or hectic, all which are removed by the absorbents as useless parts. Another cause is want of power in the part to support itself under certain irritations, whicn 17* 198 HUNTER'S PRINCIPLES OF SURGERY. may be considered as the basis of every cause of removal of whole parts, as calluses, cicatrices; also of parts pressed on. From all which it would appear that parts are liable to be absorbed from five causes: first, parts pressed on; second, parts considerably irritated by an irritating substance ; third, parts weakened ; fourth, parts rendered useless ; fifth, parts become dead. The two first appear to me to produce the same irritation ; the third, an irritation of its own kind ; and the fourth and fifth may be somewhat similar. Immediate Causes of Absorption.—The immediate causes of absorption of the body itself must be of two kinds respecting the parts, one passive, the other active. The first of these is a consciousness in the parts to be absorbed of the unfitness or impossibility of remaining under such circumstances, the action excited by the irritation being incompatible with the natural actions and existence of the parts, whatever these are; therefore they become ready for removal, or accept of it with ease. The second is a consciousness in the absorbents of such a state of part; and both concurring to do the same thing, they fall to work. When the part to be absorbed is a dead part, or extraneous matter, the whole disposition is in the absorbents. Pressure from without rather stimulates than irritates, for we find it produces thickening of parts; but if it exceeds the stimulus of thickening, it becomes an irritator. If pressure is from within, parts rather appear to give way, and absorption takes place. Interstitial Absolution.—This is of two kinds with respect to the effects, or, rather, has two states. The first, where it takes place only in part, as in the wasting of a limb, where disease of the joint has rendered it useless; in a broken tendon ; a divided nerve going to a voluntary part; or when it takes place in the whole body in consequence of disease, as atrophy, fever, &c. The second, when entire absorption takes place, and no vestige is left; and this would seem to be of two kinds, one where it takes place only in consequence of another disease, and is a necessary and useful effect of that disease, assisting infringing parts to the surface, &c.; but the other appears to arise from disease in the part itself, as a total decay of the alveoli without any disease in the teeth or gums, as also the wasting of the testicle* The first of our second division of absorption of entire parts is taking place in a thousand instances; it is gradually taking place in that partof the body between many encysted tumours and the surface, and is generally slow in its progress. Progressive Absorption.—The removal of those surfaces imme^ diately contiguous to the irritating cause, which is an absorption of necessity, is effected by progressive absorption. Absorption from pressure is the removal of the part pressed, which may either be the surface of an abscess in contact with pus, or of that part of the surface of the body in contact with some body constantly pressing, as the buttocks or hips of those who lie long on their backs. OF SUPPURATIVE INFLAMMATION, ETC. 199 Of the Relaxing Process.— Besides the modes of removing parts above mentioned, there is another process, called the relaxing or elongating process, carried on between the abscess and skin. It is possible that this process may arise in some degree from the absorption of interior parts; but there is certainly some other cause, for the skin which covers an abscess is certainly looser than it would be from mere stretching; and it is very beautiful to observe how nature goes on in her own way to produce an effect. In consequence of the pressure of pus in an abscess, Nature sets up three processes to let it out; first, progressive absorption; secondly, interstitial, by which the progressive is assisted ; thirdly, the relaxing process, making the parts yield to distension. In women, the relaxation of parts is very considerable before the birth of a child: and the old women in the country know when a hen is going to lay, by the relaxation and softness of those parts. The following cases exemplify those processes of absorption. A lady, after inflammation of some of the abdominal viscera, had the belly swell; some time after, a kind of pointing was observed in various parts of the belly, and on opening the largest a very considerable quantity of fluid (matter, I think,) was discharged; this opening was near the sternum, and the ends of the recti muscles were quite ragged. The patient died. Here was an instance of the effects of absorption, by which an exit was obtained for the matter. Suppose an abscess to go on for a long time with a smooth surface, yet if any part takes on the absorbing process the matter will be very rapid in arriving at the skin, although this process may have taken place in the thickest part. This process may be induced by an irritation in any part of the surface; thus, after opening an abscess, if matter is permitted to collect at the most depending part, it may bring on this process, whence a fresh opening will be made. This preparation [showing one] represents the front ot a chest, which contained an aneurism of the aorta; and here on the right side you see an instance of the elongating process, the cartilages being bent outwards, or elongated, to adapt themselves to its figure, „ . ~ This is another preparation (see PI. III. f. 1.),—an aneurism of the aorta. AA, ends of the aorta; B, the first sac, which contracted at C and having proceeded to d, where it met with resistance from the s'ternum DD, it became again contracted; but having produced absorption of the sternum d, E, by which an opening is made externally, the sac is again expanded. Here are two other preparations, exhibiting similar appearances.

Before I enter on this subject I shall make a few more general observations on absorption. 200 HUNTER'S PRINCIPLES OF SURGERY.

Some parts of our solids are more susceptible of being absorbed, especially by ulceration, than others under the same or similar circumstances. This is particularly the case with cellular and adipose membrane, as we often find muscles, tendons, and ligaments deprived of their connecting membrane by ulceration, as maybe observed in the opening of large abscesses. The skin itself, if affected by pressure from without, is less easily absorbed than the cellular membrane; hence we may observe, that in continued pressure from without the skin will remain whole, although the parts beneath are wasted by the absorption of the cellular membrane; but sometimes the skin is more susceptible of absorption than the cellular membrane; this may proceed from the skin acting with so much more vigour, either in opposing any injury or in taking on salutary action. Although in abscesses, in tumours, and in the case of extraneous bodies, the parts all round are equally pressed, yet we find that the progressive absorption takes place only on that side nearest the skin, and arrives at the skin only on that side: a very slight degree of pressure from within will produce this effect, so slight as would from without have produced only a thickening of parts. Bones are susceptible of a similar process. Absorption may be of two kinds,—without suppuration, or with it. The first, I believe, is universally the case with the interstitial absorption when it takes place alone, as in the absorption of callus, of the alveoli of the teeth, &c.; but the second may precede or produce suppuration where there was none before, as in old sores breaking out anew. To distinguish the second from all other modes of absorption of whole parts, I shall call that absorption ulceration which is either preceded, accompanied, or succeeded by suppuration. Absorption may be a consequence of pressure under two circumstances,— where the pressure is from diseased parts, or from extraneous substances. Of the first is that from tumours, &c.; thus, in a case of aneurism, where the coats of the artery press against the bones, the rib for instance, its coats begin to be absorbed, and, after they are absorbed, that absorption goes on in the bone, the adhesive inflammation takes place at the same time round it, and unites the circumference of the absorbed parts: another instance is where tumours make their way to the skin, without any suppuration taking place. Of this I once saw a very remarkable instance in a soldier in the Dutch service : a tumour had formed between the pia mater and dura mater, which gradually increased to a very considerable size, and had shown itself externally some time before the man died. Upon examination after death I discovered that the pia mater was absorbed underneath it; but the chief absorption had taken place on the side next the skin, for on this side the skull was absorbed, and the absorption had begun in the integuments of the scalp, which it would soon have probably ulcerated had not the man died before Nature had finished her operations; and in this case no matter was found either on the brain, skull, or in the integuments, owing, perhaps, to the pressure being made by a living part. This OF SUPPURATIVE INFLAMMATION, ETC. 201 species of absorption is attended with very little or no pain, and its effects are as trifling on the constitution, although it may be an effect of an alteration in the constitution, as the absorption of calluses in scurvy, &c. Ulceration.—I shall now take notice of that action of the absorbent system which 1 call ulceration, and which is the second species of our first division, being connected with the formation of pus, either as a consequence or as a cause; and it is this kind which always constitutes an ulcer. This process of ulceration or absorption with suppuration, is almost constantly attended with inflammation, which led me to call it ulcerative inflammation. Ulceration is generally attended with considerable pain, which is called soreness; but this does not attend all ulcerations, for there are some which are of the specific kind, which give little or no pain, as scrofula ; but even in this disease, where ulceration proceeds pretty fast, it often gives considerable pain, wherefore the pain may be in some degree in proportion to the quickness of its operation. In those cases where ulceration is set up to separate dead parts, as sloughs, it is seldom attended with pain, and it is not easy to assign the cause of this. It seldom or never affects the constitution much, although the process is affected by the constitution. What I have hitherto said of ulceration I shall illustrate by noticing what occurs in an inflammation of the peritoneal coat of an intestine. The first inflammation produced is the adhesive, which occasions an adhesion between the inflamed part of an intestine and the peritoneum lining the cavity, which remains, although the inflammation should stop here; but if it does not stop here, then the suppurative takes place, and an abscess is produced, the matter of which is collected into a regular cavity in these adhesions, and is prevented from diffusion through the cavity of the abdomen by the effects on the surrounding parts, by the preceding adhesive inflammation, as well as of that which accompanies it. This matter, by its pressure, irritates, and absorption takes place in consequence; but as none of the parts, except those between the matter and the skin, are hardly, if at all, susceptible of this irritation, no parts are absorbed but such as are so situated: hence the abdominal muscles, cellular membrane, fat, and skin are removed in preference to the coat of the intestine. If the suppuration had at first begun in different points, the parts between are absorbed until it becomes one abscess; and when it reaches the skin we have the ulcerative inflammation. It is in the same manner that Nature acts in all abscesses of circumscribed cavities, as in common abscess, inflammation of the lung of the side next the pleura, of the pleura itself, gall-bladder, liver, &c.; also in the case of lumbar abscesses. In the substance of the lungs we sometimes find abscesses go on in a different manner, and open into the cells, and this because the adhesive inflammation finds it difficult to connect the air-cells together; and that the air-cells do not take on the adhesive inflammation is evident 202 HUNTER'S PRINCIPLES OF SURGERY. from many observations. Whilst a part is under the ulcerative inflammation, irritation will increase the absorption on any part of its surface. Thus, if a large abscess forms on the thigh, opposite the great trochanter, we shall find that, from the pressure of the trochanter on the part opposite to it, ulceration will take place there likewise. An irritation we have of the same kind in milk abscesses, from the irritation of the matter in a depending part of the abscess, which shows how very easily, from the slight pressure of matter, the ulcerative process may be produced. Ulceration is, therefore, no more than a process by which parts are removed out of the way of pressure. The ulcerative process has no effect on the cuticle; but in general this is so thin as not to give any trouble, as it easily bursts. But on the fingers and hands of working people it becomes so thickened as to cause excessive pain and trouble in whitloes; and as from this cause we have so considerable a separation between the cuticle and the skin, these abscesses should be opened early. Poultices in these cases are more useful than in any other, for their moisture is absorbed by the cuticle as by a sponge, and the cuticle is rendered more dilateable. After these have been opened, or have opened of themselves, by a small orifice, the soft parts lying under are apt to push through the opening, and appear like a fungus, occasioning great pain, which is owing to the cuticle around the granulations underneath. To this escharotics have been applied; but it would appear that there is no necessity for them, as it would disappear of itself when the thickening of the parts in consequence of inflammation has gone off. But besides ulceration, the consequence of previous suppuration, which we have been hitherto describing, we have ulceration taking place where no reason can be assigned for it, except perhaps weakness be the cause, the parts not being able to support themselves. New parts are more susceptible of it than old, as cicatrices, stumps, calluses, &c. This arises from the new parts being less firm than the old original ones, as in Anson's voyage, when there was a general debility from the change of climate, &c. The appearances of ulceration are different at different times, according as the process is going on, at a stand, or the parts healing. The ulceration in the small-pox is attended with death in the parts, hence loss of substance and pitting. Restoration of Parts.—We are now to trace the operations of Nature to bring parts back as near to their original formation as possible. These operations cannot be looked on as morbid, as they are for a salutary purpose. Granulations.—These have, I believe, in general been supposed to be a consequence of, or an attendant on, suppuration ; but the formation of granulations is not confined to a breach of the solids allowed to suppurate, as from accident, or a breach of the solids, produced in consequence of suppuration, as in abscesses ; but it takes place under other circumstances, and when the first and second bond of union have failed, as in simple fractures. OF SUPPURATIVE INFLAMMATION, ETC. 203 I believe no internal canal can granulate in consequence of suppuration, except there have been a breach of continuity. And here I may observe, that when granulation does take place in such a canal, it is not on the proper coat of the canal, but on the surrounding cellular membrane. Few surfaces of abscesses granulate until opened, either of themselves or by art; therefore in abscesses of very long standing we seldom or never find granulations. In most abscesses, if not in all, after they are opened, there is one surface more disposed to granulate than the others, which is the surface next to the centre of the body in which suppuration takes place, the surface next to the skin hardly ever having the disposition to granulate ; on the contrary, it is sometimes ulcerating when the bottom of an abscess is granulating. Exposure is so far necessary for granulations, even in cases where there is an opening, that if the opening is only a small one, and the abscess is deeply seated, the latter will not so readily granulate, which often becomes the consequence of deep-seated abscesses not healing. I have said that granulations are not confined to a breach of the solids attended with suppuration ; for parts are capable of making new matter internally in cases where union by the first intention ought to have occurred. A case in St. George's Hospital first gave me this idea. I was called to a man with a fractured thigh, and made use of the usual means, but without success, for no union of the fractured parts was formed in the usual time ; and about the end of four weeks the man died with another complaint. Upon examination of the parts, I found that the upper end of the bone rose considerably over the under, and consequently there was a great cavity in the soft parts, the parietes of which were thickened by the adhesive inflammation, though not so much as if the parts had been better disposed for the adhesive inflammation. There was no extravasated blood, nor matter, nor coagulable lymph to be found, except a few threads, which were probably the remains of extravasated blood. Here the parts had lost two chances of being united, the one by the extravasated blood, the other by the coagulable lymph thrown out by the adhesive inflammation ; and Nature had begun a third, which was that of forming granulations of new animal matter on the ends of the bone and the surface of the surrounding cavity; and adhesions, you see, had taken place between the bones and soft parts, by which the bones would have been united by a bony case. Hence we find that granulation may take place without the parts being exposed, and without suppuration.* This mode of union by granulation is, I believe, much more

* [The effusion of callus in this case does not seem to differ essentially from the effusion of callus in other cases. It cprtainly cannot be regarded as a conclusive proof of the existence of granulations without suppuration and exposure, although these do. sometimes continue to form after cicatrization, as in burns and eome other cases.] 204 HUNTER'S PRINCIPLES OF SURGERY.

extensive than has been imagined; this third bond of union taking place where the parts have missed the first and second, as just mentioned. In the exposure of cavities of abscesses we have granulations going hand in hand with, and following suppuration. As the suppurative inflammation follows injuries with exposure, it seems that this inflammation is in general necessary to granulation in these cases. Granulations are an accretion of new animal substance on the surface of a wound, or a newly-formed surface composed of coagulable lymph exuded from the vessels, into which new substance the old vessels probably extend, and entirely new ones are formed, so that the granulations come to be very vascular, more so indeed than any other particular animal substance. The vessels pass from the original parts to the base of the granulations, and from thence to their outer surface. The surface of this new formation continues to have the same disposition for the secretion of pus as the parts on which they are formed had; therefore it is easier to suppose that the nature of these vessels does not alter by forming granulations, but they are completely changed for this purpose before granulations are begun to be formed, and that these granulations are the consequence of the change. They always also are of the same nature with the parts on which they are formed : if a diseased part, they are diseased ; if the disease be of any specific kind, they are of the same kind and produce similar matter. The surface of the granulations is convex, being just the reverse of an ulcerating surface, which is thus, as it were, shagreened by a great many points or small eminences: the smaller these points are, the more healthy the granulations. The colour of healthy granulations is a florid red, which would make us suspect that it is principally owing to arterial blood; when they are of a livid red they are most commonly unhealthy, and have a languid circulation in them ; however, this appearance frequently is owing to the particular position of the parts. I knew an instance of this in a young man who had a granulating wound on his leg. I was surprised to see it on some days of a healthy scarlet, and on others quite livid; but the cause of this he explained to me, by showing that if he kept it in a recumbent posture for a short time, its surface was then of a bright scarlet, but if he stood for a few minutes it would become quite livid. This appearance must have arisen from the stagnation of blood in the newly-formed vessels, and from their not possessing sufficient strength to resist the superincumbent column of blood, which sufficiently accounts for the difficulty of healing sore legs when patients are allowed to stand or walk much. Granulations not only show the state of the part on which they are formed, but also how far the constitution is affected in many cases. The chief of those which affect granulations are the irritable and indolent habits, and, still more, fevers, which must be of such a nature as to produce universal irritation in the constitution. Granulations have a disposition to unite with one another, which OF SUPPURATIVE INFLAMMATION, ETC. 205 is absolutely necessary to healing; and this is done, I suppose, in the following manner : when two granulations meet, the mouths of the opposing vessels are irritated, which causes them to embrace each other; this junction perhaps being aided by the attraction of cohesion, or they may throw out coagulable lymph, and unite in that way. I have seen granulations from the dura mater and scalp unite so closely in twenty-four hours as to be with difficulty separated, and then to bleed very freely, which shows their great disposition to unite. When the parts, and consequently the granulations, are not sound, there is not this disposition to unite, and a smooth surface is formed, which continues to secrete pus. I conceive the internal surface of a fistulous sore to be of this nature, and somewhat similar to the urethra in gleet. Ulcers of this kind are cured by exciting inflammation in them. Granulations have less powers and shorter lives than originally formed parts. Different animals have different periods of life, and so have granulations, and sometimes they seem to be formed with a short period of existence. They often die and slough off without any visible cause, and, coming down to the original parts, a fresh crop of granulations is formed, which in a certain time will again slough off without any apparent change in the constitution. Many small wounds would perhaps do much better without any dressing. The blood, coagulating and drying, forms itself into a scab, which falls off and shows that Nature has completed her work under it; the same will often happen when small suppurating sores are suffered to dry. This is a circumstance not attended to, perhaps, as much as it ought: even compound fractures with a small opening, if suffered to proceed in this manner, will often give but little trouble. In blisters, where the cuticle is not removed, the process is exactly similar. It would be a great advantage to us to ascertain what sores require dressing, and what do not. I believe all cutaneous sores do best without dressing; excoriations and little pimples had best be left to themselves, for often when applications are made to any of these, a hundred little pimples will sprout up: when this is the case, I make it a general rule to desist from any application. A young gentleman had a small pimple on his leg, to which a little ointment was applied, and in a day or two the surrounding parts were covered with similar pimples : these, being treated with similar applications, spread, until the whole leg was covered with them. When I was consulted, and asked what was to be done —" Nothing." " How is that ?" " Can anything be easier ?" I said ; " do nothing to the leg." " Then the stocking will stick to it." " Let no stocking be worn: put the boy on a pair of trousers." The advice was taken, and the leg dried up and healed directly. Cicatrization.—Immediately on the formation of granulations, cicatrization would seem to be in view; contraction is going on in every part, but principally from the edges to the centre, so that the sore becomes very small, without much new skin. This contrac- 18 •206 HUNTER'S PRINCIPLES OF SURGERY.

tion is easiest effected on loose parts, but with difficulty when over bones, as on the scalp, shin-bone, &c, where the granulations cannot contract much. This observation should direct us, in operations on such parts, to leave as much skin as possible. This contraction continues until the whole is skinned over ; but their greatest power, or at least their greatest effect, is at first. This contraction can be assisted by art, which shows there is a resistance; this is done by bandages, but these should be avoided at first, while there is inflammation, and until granulations are formed, otherwise they might prevent the granulations rising. Besides the contractile power of the granulations, there is a similar power in the surrounding edge of the cicatrized skin, which assists the power of the granulations, and is often greater than that of the granulations; this may be seen in sugar-loaf stumps, where the skin grows round and embraces the granulations like a ring, appearing to squeeze them out; but it is only in the new skin, the old being loose all round. This contractile power prevents the necessity for so much new skin, the surrounding old skin being drawn over the parts. The advantage of this is very evident, the original skin being more fit to live than the new, and less liable to ulceration. As the granulations contract, the old surrounding skin is stretched, and is probably elongated. If it is elongated, it must be so by the interstitial deposition of new matter. Of Skinning.—When a sore begins to heal, the old skin, which had been inflamed, then becomes whitish, and especially near the edge: this is one of the first appearances of healing. The new skin is a very different substance with respect to texture from the granulations on which it is formed; but whether it is an addition of new matter, or a change in the surface of the granulations themselves, is not easily determined. We find new skin generally taking its rise from the surrounding old skin, as if elongated from it; but that is not always the case, for in very large old ulcers, where the edges of the old skin have but little tendency to contract, new skin forms in different parts of the ulcer, standing on the surface of the granulations like little islands. These little specks show that the ulcer is healing slowly, and it seldom or never takes place the first time a part is ulcerated ; but the old surrounding skin assists by shooting towards the new. The granulations may perhaps acquire a disposition to skin from their being in the neighbourhood of the old skin, but it is plain they can take on this disposition without that assistance. Skinning is a process in which Nature is always a great econo> mist. We never find that new-formed skin is so large as the sore was on which it was formed. This is brought about by the contraction of the granulations, which in some measure is in proportion to the quantity of the surrounding old skin. If a sore be in a part where the surrounding skin is loose, as the scrotum, the contractile power of the granulations being not at all prevented, very little new OF SUPPURATIVE INFLAMMATION, ETC. 207 skin is formed ; whereas if the sore is on a part where the skin is tight, as the scalp, the new skin is nearly as large as the sore. Nature of ihe newly-formed Cutis. — When granulations are formed near a bone, the skin is at first fixed ; but it gradually becomes loose, from elongation, by continued attempts at motion. Motion given to the part so affected must be mechanical, but it becomes a stimulus by which the parts become conscious of their not being able to exist as they are, therefore the lymphatics set to work to absorb all the adventitious substances which prevent their motion. Medicine has not as much power as we could wish in assisting this process ; however, mercury seems to have nearly the same effect as motion, especially when combined with camphor, and should be used. When everything else fails, electricity may be tried, for it has restored the motion of parts after they have been fixed from inflammations after strains. The newly-formed skin has no indentations, or lozenge-shaped marks, on it, like the old, nor has it the living principle so strong. The new cutis is at first very vascular, but afterwards becomes less so, the vessels perhaps being obliterated, or converted into absorbents, and so becoming white. Cuticle.—That formed on the new cutis is at first horny, but afterwards shining. It is sooner restored than the cutis, and is formed at once from every part of the cutis. Rete Mucosum.—This is much longer in forming than the cuticle, and sometimes is never recovered, as we see in wounds, blisters, &c, in blacks, their skin in that part remaining white for ever.

Effects on the Constitution.—I have divided diseases into local and constitutional; and when on local, I observed that they, and especially inflammation, had secondary or sympathetic affections, which were immediate or remote. The immediate were considered when on inflammation, namely, the sympathetic fever. The remote are now to be treated of. One would suppose that the suppurative would only so far affect the constitution as by the preceding inflammation which produces it; but the contrary is sometimes the case, and the suppurative will produce worse symptoms than the inflammation itself. The condition which the constitution takes on after suppuration is sometimes productive of those diseases termed nervous, as locked-jaw, hysteria, spasm on the muscles of respiration, restlessness, debility, &c, all of which seem to arise from the suppurative action, and are not salutary effects, but harass the constitution and even produce death. The locked-jaw I shall defer for the present, and consider hectic or sympathetic fever. Hectic fever is a remote constitutional sympathetic affection, and appears to have a very different origin from the other remote sympathizing effects, though in general the consequence of a local disease. It is the constitution affected by a local disease, pr irritation, which it is conscious it cannot cure; for while the inflam- 208 HUNTER'S PRINCIPLES OF SURGERY.

mation lasts, which is only preparatory to an immediate effect of most injuries, in those parts at least which can most affect the constitution and call up her powers, there can be no hectic. It takes its rise from a variety of causes, which I shall divide into two: 1st, From an affection of vital parts; 2d, From an affection of parts not vital. The only differences between these is in the time of the hectic's coming on", and its rapidity and violence when it does come on. In vital parts, hectic will be produced by many complaints which will not produce it in other parts, as scirrhus of the stomach or mesenteric glands, also diseases of the lungs or liver. These also produce other symptoms, according to the nature of the part injured and of the injury; as coughs, when in the lungs; sickness and vomitings, when in the stomach; dropsies and jaundice, when in the liver. When the hectic arises from disease in a part not vital, it is generally in parts where such a quantity of mischief can take place as to make the constitution sensible of it, as the large joints. In small joints, although the same local effect takes place as in large ones, yet the constitution is not made sensible of it, so that we find scrofulous joints of the toes, &c, not affecting the constitution with hectic, and the ankle, elbow, and shoulder are much longer in affecting the constitution than the knee or hip. Although hectic commonly arises from some incurable local disease of a vital part, or of a common part of some magnitude, yet it may be an original disease of the constitution; the constitution may fall into the same action without any local disease whatever. Hectic may be said to be a slow mode of dissolution; the general symptoms are those of a low or slow fever, attended with weakness ; but more the action of weakness than real weakness, for on the removal of the part causing the hectic there is immediately the action of strength produced. The particular symptoms are: debility; small, quick, sharp pulse; the blood forsakes the skin; there is loss of appetite; often vomiting; wasting; tendency to sweating, especially when in bed; constitutional purging; urine clear at one time, and at another depositing a branny brick-dust sediment; dissolution. This disease has been supposed to arise from absorption of pus; but I have long thought that the blame has been improperly laid to the absorption of pus, and the following facts will make this evident. First, hectic takes place where there is disease, and no suppuration in vital parts; also in many inflammations before actual suppuration has taken place, as in many of the large joints, called white swellings, while the same kind and quantity of inflammation and suppuration in any of the fleshy parts, and especially such of them as are near the source of the circulation, have in general no such effect. Therefore in such cases it is only an effect on the constitution, produced by a local complaint having a particular property. I have said that with all diseases of vital parts the constitution OF SUPPURATIVE INFLAMMATION, ETC. 209 sympathizes more readily than with many other parts; and also all diseases of vital parts are more difficult of cure than those not vital; as also diseases of bones, ligaments, tendons, affect the constitution more readily than of muscles, skin, cellular membrane, &c.; and we find these general principles hold good in universal remote sympathy with local disease of those parts and structures. When a disease is in the vital parts, and is such as does not kill from the first constitutional effects, then the constitution becomes teazed with the complaint, which is destroying the necessary actions of health which are vital. In diseased joints there is not a proper power, or rather, perhaps, disposition to produce salutary inflammation and suppuration for their recovery; therefore the constitution is irritated with an incurable disease. If absorption of pus always produced such symptoms, I do not see how any patient who has a large sore could escape this disease, because we have as yet no reason to suppose that any one sore has more power of absorption than another. If in those cases where there is hectic the absorption of pus is really greater than when the habit is healthy, it would be difficult to determine whether the increase of absorption is a cause or effect. If it is a cause, it must arise from a particular disposition of the sore to absorb more at one time than at another, even while in a healthy state. What reason we have to suppose that a sore in a healthy constitution has power to absorb more at one time than at another, I do not see. If this increase of absorption does not depend on the nature of the sore, it must take its rise from the constitution; if so, there is a peculiarity of the constitution ; therefore the whole of the symptoms cannot arise from the absorption of pus, and the cause must be a peculiar constitution and absorption combined. If the absorption of matter produced such violent effects as are ascribed, which are never of the inflammatory kind, but of the hectic, why does not venereal matter produce the same effects ? We often know that absorption is going on by buboes taking place, yet no symptoms appear until the matter appears to produce its specific effects, and these symptoms are not very similar to those called hectic, though from reasoning we should expect that venereal matter would act with more violence than common matter from a healthy sore. Again, as matter is often formed on the inside of veins in inflammation of those cavities, and this matter enters directly into the circulation, why have we not the hectic symptoms in these cases We have the inflammatory, and sometimes death. We also find the matter of large abscesses which have been produced without visible inflammation, such as many of the scrofulous kind, wholly absorbed, and that in a very short time, yet no bad symptoms

From all these facts and reasonings we may conclude that the absorption of pus from a sore cannot be the cause of so much mischief as has been generally supposed. If it was owing to matter in 18* 210 HUNTER'S PRINCIPLES OF SURGERY. the system, I do not see how the symptoms could ever stop until suppuration ceased; yet we often do find that they get well before suppuration ceases, even when no medicine was given; and in the case of inflammation of the veins, there is reason to believe that after all the bad symptoms are gone suppuration is still going on, so that though matter is still passing into the constitution from the vein, hectic is not produced, which it must be if it was caused by matter getting into the circulation. But I much doubt the fact of absorption going on more in one sore than another. In large abscesses hectic seldom comes on till they are opened, though they have been forming matter for months. In such cases the disposition often comes on soon after opening the abscess: in others very late; but till the stimulus for restoring the parts is given no such effect can take place. If the parts were disposed to heal, no such hectic disposition would come on. In diseased joints also, if the parts are capable of taking on salutary inflammation we shall have only the first sympathetic inflammatory fever; but as they seldom do this, the constitution is teazed by the complaint not taking on immediate and salutary steps towards a cure. Hectic, therefore, would appear in some measure to depend on the parts being stimulated to produce an effect beyond their powers, and this stimulus is sooner or later in taking place. Treatment of Hectic.—We have as yet, I am afraid, no cure for this. I believe the cure consists in the removal of the cause, viz.: the local disease. Strengthened and antiseptics are recommended. Strengtheners are proposed on account of the debility, which has evidently taken place; and antiseptics, from the idea of absorbed pus giving the blood a tendency to putrefaction. To prevent, both these effects taking place the same medicines are recommended, namely, bark and wine. Bark will in most cases only assist in supporting the constitution; I should suppose it could not cure the constitution of the disease; however it may render it less susceptible of it. When hectic comes on from some specific disease, as from venereal irritation, the bark will enable it to support it better than it otherwise would have done. Wine, I am afraid, rather does harm, as it increases the action of the machine without giving strength, a thing to be carefully avoided. However, I have not yet made up my mind about wine. When hectic arises from the disease of such a part as the system can bear the loss of, the part should be removed. On removing the cause (as by amputation of an extremity,) the pulse, from being very quick, returns to its usual state; I have likewise knowm the patient sleep the first night without an opiate, after having had little or no sleep for a week before, and the sweats called colliquative have been stopped; and I have known purging immediately to stop. Perhaps the pain and newly excited action of the constitution may assist in the abatement of the symptoms. Of Dissolution.—To the hectic I have joined another disease, PRACTICAL ILLUSTRATIONS, ETC. 211 arising from suppuration, which I have called dissolution, because few recover from it. It may arise in long-continued suppurations, which may not be incurable in themselves, and in this it differs from hectic. Dissolution seems more the effect of the past than of the present, which is the reverse of hectic. We never find this take place in consequence of small wounds, or such as affect the constitution but little, but rather after bad compound fractures, amputations, &c. It appears more in hospitals than in private practice; more in large towns than in the country. In cases of compound fractures and amputations, we find the constitution often capable of going through the inflammatory sympathetic fever, producing suppuration and granulation, and continuing this for some time, yet sinking under them at last, and often without any apparent cause, the effect taking place more readily if the patient was in full health before the operation, than if he had been for some time accustomed to hectic symptoms. " The first symptoms are generally those of the stomach, shivering ; vomiting immediately follows, if it does not accompany it; a small quick pulse; perhaps bleeding from the whole surface of the sore: often mortification and speedy dissolution. Here is a very fatal disease taking place in some almost immediately, and when everything appears to be within the powers of the animal. It therefore cannot immediately arise from the sore itself: yet the sore certainly assists, because we never see the disease take place where the sore is healed. The removal of the local disease will not prove effectual for the cure of this as it does that of hectic, nor do I find anything that has any effect. CHAPTER XV.

practical illustrations of the preceding subjects.

Union of a broken tendon ;—rupture of the tendo-Achillis ;—principles of treat ment;—impossibility of causing voluntary contraction of the rnuscle ;— management of the injury ;—pain and inflammation triflings-length of cure. —Empyema;—varieties of contained fluid ;—symptoms differing;—ultimate effects of contained fluid the same;—to be distinguished from disease of the heart.—Symptoms of the disease peculiar;—general;—sympathetic—Operation— After-treatment.—Pericarditis.—Adhesion;—suppuration fatal— Emphysema from fractured rib ;—operation to be avoided.—Peritonitis ;— symptoms;—rapid progress;—true and erysipelatous.—Puerperal, not from inflammation of the uterus;—causes ;—arising after tapping.—Hernia.—bavarian section.—Opening cavities of joints.—Ganglions.—Inflammations ot the eye—Phlebitis following venesection ;—causes ;—extension;—frequency in the horse.—Arteritis.

Union of a broken Tendon.—The treatment of a broken tendon is very similar to the treatment of a fractured patella, because 212 HUNTER'S PRINCIPLES OF SURGERY. their uses, and in some degree their situations, namely, the giving way of an intermediate substance between the power (that is the muscles,) and the resistance. All come under one general principle of cure, though the mode of treatment is somewhat different. These intermediate parts are principally tendons, probably some ligaments, and bones. The fracture of a tendon is probably always produced by the power being in action, and the resistance counteracting at the same time and with great velocity. We might suppose that every tendon in the body would be liable to such accident, but I believe there is only one that stands any chance of such effect by the natural exertions of the body; this is the tendo-Achillis.* There is also, probably, but one bone in the human body which can be broken in the same way, that is the patella; though there may be instances of processes of bone being turn off near their insertion, which would be somewhat similar. The tendo-Achillis seems liable to be broken by the natural actions of the body, from having at the same time to sustain the action of the power and of the resistance also. When it has only the action of the muscles to contend with, there is no danger of its rupture, because the tendon is capable of supporting a much stronger power than that of the muscles. Though the tendon is continually in this state, yet there is little danger, because when the action is voluntary all the actions tend to support one another; but in a careless unguarded action the motion is more violent and quick, and the part less prepared against it. I believe fracture of this tendon often happens when a person is fatigued and off his guard, as after dancing, &c, and after the muscles have acted spontaneously, as in the cramp; at least it happened to me after dancing, and after a violent fit of the cramp. The general principle of cure in parts displaced is the replacing them in their natural situations, which is the whole cure in some, as dislocations, and the first step to be taken in every case where the continuity of parts is broken. When the tendon is broken it is seldom attended with pain in the parts. It commonly gives a pain, which instantly seizes the calf of the leg. The noise or snap which it produces gives no idea of the mischief done; but being at the same time attended with pain in the calf of the leg, and the patient not being able to walk as usual, he conceives that some one has struck him with a hard body on the calf, and if he is so situated as not to have been liable to a blow*, he becomes puzzled to conceive what can have happened. We generally find that the muscle is thrown into a state of cramp when the tendon gives way, losing the power of relaxation by the will, or of itself. As a surgeon is seldom present when such an accident hap-

* [This is a mistake: the tendons of the patella, triceps extensor cubiti, and quadriceps extensor cruris are sometimes ruptured from a sudden and abrupt exertion of these muscles. An example of the latter kind is at this moment in one of the wards of St. George's Hospital. I may also mention that fiactures of the collar-bone, from muscular exertion, are not very uncommon.] PRACTICAL ILLUSTRATIONS, ETC. 213 pens, it is often allowed to remain some time in that state; but the pain often leads to the right mode of cure, the patient squeezing the muscle down with his hands, which a surgeon should do if at hand. The broken ends will always at first be some distance from each other, because they are pulled apart by opposite forces. The parts should be allowed to remain nearly in their natural position; no inconvenience will attend a small separation of the broken ends of the tendon, namely, half an inch or so; whereas considerable disadvantage would arise if we were to push the two broken ends together by throwing back the heel (which has been the general practice). The only circumstance that would seem to forbid such practice, namely, letting the broken tendons remain without a bandage, is, that the muscle will lose half an inch of its power of contraction, which the motion of the ankle may or may not lose; but though this may be lost at first, we know muscles will acquire it again afterwards, and therefore no attention need be paid to this objection. The advantage of not throwing the heel up, and of allowing the tendon to heal nearly in its natural position is, that the patient may be enabled to walk from the very beginning of the cure, a very desirable circumstance. However, it is not necessary to adhere rigidly to either of these modes of treatment, but to adopt a medium between the two, which will be best. The heel may, therefore, be a little raised during the time of walking only, by raising the heel of the shoe. A roller should be passed several times round the calf of the leg, and kept constantly applied, as we cannot guard against the involuntary actions of the muscles ; and at night we may apply an apparatus consisting of a leathern slipper or sock, with a strap from the heel to be fixed to a belt, in order to steady the muscles. . When the tendo-Achillis is broken, there is but very little inflammation attendant; but some general fulness comes on about the small of the leg and ankle, the skin looks dark from the effusion ot blood, and the parts have a firm feel, from coagulable lymph being thrown out. This firmness of the cellular membrane increases near to the fracture laterally, and this assists in keeping the tendon in its place. The inflammation hardly requires any particular treatment when the foot is in a proper position. As I would not restrain the patient from walking almost from tne very beginning, (the inflammation may prevent it for the first day or two,) it is necessary to give him some directions how he is to manage the muscles under the cure, as walking cannot be performed in the usual way. I have recommended to keep the position ot the toot nearly at a right angle with the leg, as in standing, but not quite so, the heel being a little raised, by some pieces of leather put into the shoe, which may be removed one by one. When he walks he must turn his toes out, and carry the inside of his foot forwards without attempting to bend the joint of the knee; indeed, the latter precau tion is unnecessary, for this motion is only necessary when thehee can be raised from the ground, which he cannot do. 1 his toot win 214 HUNTER'S PRINCIPLES OF SURGERY. be for some time the leading foot in walking, for it will be an easy motion to set it forwards before the other, especially if the heel is not much raised; but it will be impossible to set the other foot forwards and leave this behind. The patient will be hardly able to mend his pace for two months, except it be by getting familiar with his present mode of walking. The ankle and foot will swell occasionally, especially in the evening; and this may continue more or less after the tendon is united, but is of no importance. Three or four weeks after the accident he may remove the roller from the calf of the leg, and about the same time leave off the slipper at night. We cannot say when he may use the muscle of this tendon: that will depend on the fitness of the tendon to be used, which can only be known by the power the patient has of putting it to use. About two months after the accident we find him gradually bringing his toes more and more forwards, until he at last walks as usual.* It is impossible for a patient with a fracture of the tendo-Achillis to act with the gastrocnemius and soleus muscles, if he were to try to do so. When the Duke of Queensberry broke Tiis tendo-Achillis he was immediately aware of what had happened, and pointed out to me the broken ends. He readily submitted to my reasoning: walked about his room as well as he could, and found it impracticable to contract the gastrocnemius muscle. Some surgeons thought the tendon could not be broken, because he was walking about his room; but in such a case the patient has no more power to contract his gastrocnemius and soleus muscles than to jump over St. Paul's. Of simple Fractures.—A fracture is the solution of continuity of a bone, whereby more or less of a cavity or space is allowed between the broken parts. It often, if not always, happens that the surrounding soft parts are also torn by the broken ends of the bone. On the surface of this broken or torn part are the mouths of many ruptured vessels, which immediately fill the cavity writh blood. This is the first stage of the bond of union. This blood, having the living principle in it, unites with the torn surfaces, in the same manner as in ingrafting the living parts of animals. An inflammation generally comes on, similar to that which produces adhesions where there is no ruptured vessel, which is of service in this case for the better union of surrounding parts, where extravasated blood cannot enter, by which means the callus becomes larger than it would otherwise be. Vessels are either continued from the old parts into this extravasated blood, or it forms new * [The period of perfect recovery is generally protracted several months before the ultimate organization of the uniting medium is effected, in consequence of the low powers of vitality which tendinous parts possess. Simple incised wounds of tendons, as in amputation, are observed to heal without difficulty; but the union of ruptured tendons is a much slower process, depending upon the slow reproductive powers of these parts. At first the union is by cellular membrane, which gradually becomes harder and tougher: very often it becomes osseous, as in Mr. Hunter's own case; but very frequently it remains a fibrocartilaginous knot, which never assumes the tendinous character.] PRACTICAL ILLUSTRATIONS, ETC. 215 vessels in its own substance; this substance then goes through the regular stages of ossification, becoming first cartilaginous and then bony. Thus 'new parts are formed and old ones united without the occurrence of any considerable inflammation, and all owing to this circumstance of the extravasated blood being preserved, and allowed to retain its living powers. All the surgeon has to do in such cases is to put the parts as much into their natural situation as possible, and to keep them there by art in the easiest way to the patient that he can. The same idea and the same practice is extended to all unions by the first intention. The position of the patients themselves, when the fracture is in the lower extremities, (abstracted from the nature of the fracture itself,) has been of late a consideration. It has been a question whether they should lie on their backs or on their sides. I am inclined to prefer the back; for, from the experience of one patient, who had the same thigh-bone broken twice, lying on the back was the easiest, though it was the last, method of lying: and I conceive that it is a position that can be borne longer than that on the side. The pain arising from fracture is but little, only from the bones either tearing or wounding the soft parts. The inflammation is of course but little, if the parts have not been violently torn. Of Compound Fractures.—If the violence of the fracture has continued the laceration through the skin, so as to have allowed part of the blood to escape, and to have exposed the remainder sufficiently long to allow it to lose its living principle, so as to become an extraneous body, unfit for the purposes of union, then the suppurative inflammation must take place, and granulations finish the union which the blood was incapable of doing. In this case the granulations become the origin and seat of formation of the callus, and go through the regular changes until they become ossified, as was the case with extravasated blood in simple fracture. In these cases considerable fever and inflammation, proportioned to the local injury, come on. There are two cases which partake of the nature both of simple and compound fracture. The first is, where the injury was a simple fracture at first but afterwards becomes a compound, which I shall call the simple compound fracture; the other is when the fracture is a compound one at first, but the external wound so small, and the soft parts having sustained so little injury, as to require very little different treatment from what happens in the simple fracture; and this kind I call a compound simple fracture. Of the Simple Compound Fracture.—This is owing, in some cases, to some part of the extravasated blood losing its living principle, and then acting as an extraneous body ; in others it is owing to the sharp end of the bone pressing against the inside of the skin and causing it to ulcerate. In these cases we see inflammation come on, at first, as in simple fracture, with that mildness which generally attends such cases; but some days after a stimulus is given by the broken pieces of bone, or by the blood which has lost its living 216 HUNTER'S PRINCIPLES OF SURGERY.

principle, or from the parts being beyond the power of union by the first intention, and the suppurative inflammation comes on. The cases which I have seen of this kind have been much less dangerous than fractures that were compound from the first. The only reason I can assign for this is, that the whole of the blood produced from the lacerated parts does not lose the living principle, so that a considerable portion becomes so much a part of the living solids during the first few days as to be able to keep its ground, only a portion of it acting to produce the suppurative inflammation, which is therefore less. The treatment of the simple compound fracture is very simple: the limb may be bound up in general as in a simple fracture, with splints and a roller, only leaving a free space for the change of dressing and to keep the parts clean. Of the Compound Simple Fracture.—The effect of this is similar to the foregoing, though the cause is different. There are cases of compound fracture where the wound in the skin is but very little at first. If the broken ends of the bone have not done much mischief to the soft parts, and only made a small wound in the skin, they may be treated as simple fractures, which gives us an opportunity of retaining the uniting matter. By immediately closing up the wound with a bit of sticking-plaster, or a little lint soaked in the blood and allowed to dry on it, the greater portion of the wounded parts and broken ends of the bone will unite by the first intention, and only those parts of the solids which are exposed will suppurate. This small suppuration will oblige the surgeon to leave the wound in the skin free from bandage, in order to be enabled to look at it occasionally; though, from some accounts, it might seem that even this was not necessary. This mode of treating it as a simple fracture obliges it to heal as such. This practice has been followed even when the laceration in the skin was considerable; but I have not seen a sufficient number of cases to say how far it may be extended. Inflammation, Suppuration, and Ulceration of circumscribed Cavities.—All circumscribed cavities, as the pleura, peritoneum, &c, admit of the three inflammations. They may be formed into true and distinct abscesses by adhesions inclosing the matter, as in common abscess. If the inflammation does not stop at the adhesive, then suppuration follows, and ulceration also becomes necessary for the exit of the matter, which is an extraneous substance. A material circumstance happens in the inflammation of cavities containing vital parts, which is, that very little sympathy exists between the surrounding part and the parts contained, whence the inflammation of the one is not always continued to the other ; thus, inflammation of the peritoneal coat of the abdomen and of the intestine may exist without inflammation of the inner coat of the intestine. But this does not hold good universally, for inflammation of the tunica vaginalis spreads through the whole body of the testis. Inflammation of the Pleura.—This membrane is more subject to PRACTICAL ILLUSTRATIONS, ETC. 217 inflammation than any other investing membrane. Probably this does not arise from any difference of structure, but from its situa tion, by which it is exposed to the operation of cold air, and fron its contact with the lungs. Perhaps there is hardly one in fifty who at the age of fifty, is without adhesion of the lungs to the pleura We often find the lungs adhering to the whole surface of the pleura lining the thorax, and it does not seem necessary that inflammation should take place on both surfaces to produce adhesion. Abscesses may be formed here, either having the matter inclosed in a particular bag or diffused through the whole side, forming one large abscess; hence true and false empyema. Empyema.—The cavity of the chest is subject to the two diseases of other circumscribed cavities, dropsy, and inflammation and suppuration, or empyema. These two kinds of disease will have some of their symptoms very different, though the symptoms arising from the ultimate effect, namely, the collection of fluid in the chest, will be nearly the same in both. But as this cavity has connexions with parts whose symptoms when diseased will be very different from those of this cavity simply, and as those parts will sympathize with the diseases of this cavity, we shall find that a complication of symptoms will often take place which may mislead the judgment so much as to make us suspect that the sympathizer is the seat of the disease. This sympathizer is the heart; and as a disease of this part has produced symptoms which have been lately called angina pectoris, we find that it requires particular attention to be paid to the specific symptoms of empyema, to separate them from those of the heart. The general cavity of the chest is divided into two distinct cavities : therefore whatever disease affects one simply, cannot affect the other by its having affected this. Water may collect in the cavity of the chest almost at once, without giving much previous notice. It may be the consequence of various causes, as cold, fever, &c. The symptoms arising from the presence of a fluid are either peculiar, common, or sympathetic, which last may or may not occur. The first true specific or peculiar symptom arising from an extraneous fluid, in some considerable quantity, in the cavity of the chest, is difficulty of breathing, which is always an attendant, and is distinguished from difficulty of breathing from other causes by this, that the patient is always able to breathe much better in certain positions. This position will vary according to circumstances: if water is only on one side, the person can lie on that side, and on that side only; if on both sides, he can lie on his back, not horizontally, but with the chest raised as much as possible. He feels the fluctuation of the fluid within the chest whenever he moves, especially when he raises himself up. I have heard patients often say that'they could hear the fluid move. The fluid is felt pressing like a weight on the diaphragm. An anasarcous habit often takes 218 HUNTER'S PRINCIPLES OF SURGERY. place, and sometimes ascites. These two last symptoms would seem to arise from a universal irritable debility. The second, or common symptoms with other diseases, of those parts are difficulty of breathing, and of expanding the chest; great lowness and oppression ; a feeling of suffocation or of dissolution. The third, or sympathetic, symptoms are often great irregularity of the pulse, palpitations, flutterings. When the symptoms are known to arise from the presence of a fluid in the chest, it should in general be let out by an operation called paracentesis thoracis, which is only making an opening into the thorax and allowing the fluid to flow out. The wound should be made to unite by the first intention. The fluid to be evacuated may be of various kinds: as blood from a ruptured vessel, or wound made with a ball or cutting instrument; or extravasated serum, as in hydrops pectoris; or pus, the consequence of inflammation. Whatever the fluid is which is to be discharged, I have always found suppuration, take place in all the operations I have seen performed ; for when the discharge was nothing at first but serum, (as water in ascites), yet afterwards it gradually changed into pus. This arose simply from keeping the external wound open. I am inclined to think that nothing could have saved these patients but resolution of the inflammation, and the parts falling back into their natural disposition. This, as I have mentioned, sometimes takes place in common abscesses, especially those of a scrofulous kind, and in the present cases it might the more readily take place, as there is here no change of structure or granulation of the whole surface of the pleura or lungs. However, wounds have been made into the cavity of the thorax, suppuration has taken place, and yet the patient has got well; but how this has been brought about I cannot tell.* General Murray, to whom I have often expressed a wish to peep into his chest, has been twice wounded in this way. I tried the experiment by shooting a dog; but both Nature and the dog cheated me, for I intended to keep open the wound until the whole surface of the pleura had taken on suppuration, when I meant to let Nature have her way and cure the dog as she pleased, and then I intended to kill the dog and see what she had done. But the dog would always lie on the wounded side; and when, after death, I examined it, I found the lungs had adhered to the wound and prevented the inflammation spreading over the surface of the lungs. The wound, after the evacuation, therefore, should be united as quickly as possible, to prevent the whole pleura from sup-

* [There cannot be any doubt that the cure is effected in these cases by the obliteration of the cavity of the pleura, partly by coagulable lymph which is effused at the same time with the serum or pus, and partly by granulation ; the cavity of the pleura being precisely under the same conditions as a common abscess, and healing by the same methods. In these cases the patient seldom regains the power of complete expansion of that side of the chest, which alway» remains in a more or less contracted and flattened state.] PRACTICAL ILLUSTRATIONS, ETC. 219 purating, which would destroy the patient in nineteen cases out of twenty. Inflammation of the Pericardium.—The cavity of the pericardium is not so apt to produce universal adhesions as that of many other cavities.* When it goes no further than adhesion the patient lives, although this produces many disagreeable symptoms, as palpitation of the heart, irregularity of the pulse, great oppression and faintings, which in general produce a bad state of health, a great debility, and symptoms which have gone by the name of angina pectoris. If the inflammation approaches to suppuration, it will certainly kill. Emphysema.—It will not be improper here to say something of the treatment of patients affected with emphysema arising from a wound in the lungs by a fractured rib, for if any surgical operation is necessary, great caution is required not to make the wound communicate immediately with the cavity of the thorax, in order to avoid the mischief above described. If the lungs are wounded by a fractured rib, we know that the pleura must be wounded, and that there must be a communication between the cells of the lungs and the cavity of the thorax. There is also a communication between this cavity and the common cellular membrane of the body by the wound in the pleura. The air escapes from the lungs into the cavity of the thorax, and in the act of respiration is squeezed into the cellular membrane of the body. The internal wound does not inflame so quickly as the external, because the internal depends on extravasated blood for the renewal or adhesion of parts ; and the wound of the lungs, from its being in contact with the air, may be considered as an external wound, while that of the pleura is an internal one ; the former will therefore probably heal sooner than the latter, whereby the air will be confined in the cavity. The operation for the relief of this disease is making a perforation into the cavity for the relief of this disease, which operation should be religiously avoided, because it will produce the suppurative inflammation all over the internal cavities, and most probably make the wound in the lungs ulcerate. If an external opening is necessary, it should be made at some distance from the fractured rib, and never on the rib itself. If this is not attended to, it will make what was at first a simple a compound fracture, which probably would produce the same effect as an incision at once into the cavity of the thorax; or if it did not produce this evil, would produce adhesive inflammation quickly about the fractured rib,

* [This may be accounted for by the unintermitting action of the heart, which must present the most unfavourable conditions imaginable for the organization of the lymph. The opposing surfaces of the pleura or peritoneum may be preserved by the patient in the most perfect state of apposition during the progress of inflammation, by breathing only by the chest or diaphragm, according as the case may be. But the heart has only one mode of action, which must continually tend to disturb the process of union, just in the same manner that the continually recurrent action of the sphincter ani prevents the cure of fistula; in that situation.] 220 HUNTER'S PRINCIPLES OF SURGERY. which would prevent any future escape of air from the pleura, which should be allowed; and for the same reason the patient should not have a roller bandage put on, as this would cause an impediment to the respiration by the other lung, and, by preventing the escape of the air, cause the whole contents of the thorax to be pressed to the other side. Peritoneal Inflammation.—This inflammation is attended with great pain, not of the colicky kind, but a violent soreness or tenderness on external pressure. The fever or sympathy of the constitution, arises much higher than if it arose from the inflammation of a common part, and runs through all its stages much sooner than another part. When the immediate cause of these constitutional symptoms is not known, and the effects are violent, it has been called a fever, and the chief attention has been directed to checking this fever ; but the symptoms are merely the consequence of the inflammation in a part by which the constitution is easily affected ; so that if it wrere possible to restore the healing disposition to the cavity of the abdomen, the other symptoms would vanish and health be restored. A diarrhoea sometimes comes on, but at other times there is costiveness, both of which I am inclined to think may be considered as sympathetic affections. It is perhaps almost impossible at first to say what the inflammation is, whether the true inflammation or the erysipelatous, because we are only guided by the constitutional symptoms, not by the appearances. A person in seemingly tolerable health attacked at once with so violent a local disease will be at first roused, which will make it appear a truly inflammatory complaint; but if it is erysipelatous he soon sinks. Still at first the apparent indication would be bleeding, and that largely; but if it is of the erysipelatous kind we may be led by those symptoms beyond the quantity suitable to the constitution. Yet I do not know wdiat we can do better; I should be inclined to reduce the patient to the lowest pitch rather than allow suppuration to take place, for that would certainly kill. In whatever light we consider an inflammation of the peritoneum that is capable of producing suppuration, it is one of the most dangerous diseases we can meet with. How far in such cases it might appear desirable to make an opening into the abdomen, and throw in warm water repeatedly to wash away the matter, I will not undertake at present to determine. Peritoneal Inflammation after lying-in.—Inflammation often attacks some part or the whole of the peritoneum in women some days after childbirth, and hence has been called puerperal fever, from supposing it to be a fever peculiar to that state, and the inflammation of the peritoneum a consequence of this fever, whereas the fever is only a sympathetic symptom of the inflammation; but as this inflammation is connected with vital parts, the sympathetic fever is so much the more violent and dangerous. I believe I am the first who formed this idea of this disease. Why such a disease should occur after so natural an operation PRACTICAL ILLUSTRATIONS, ETC. 221 is not easily explained. It does not arise from an inflammation of the substance of the uterus first taking place, as we might at first naturally expect; for if the uterus did inflame in consequence of delivery, there would be no more necessity for the peritoneum of that viscus to inflame than for the peritoneum of an intestine to inflame when the intestine is itself inflamed, which it seldom does; and if the peritoneum of the uterus inflamed in consequence of inflammation of the uterus, that is not a necessary cause why the whole peritoneum should inflame, excepting the inflammation was carried so far as to produce suppuration on that part of the peritoneum. But the substance of the uterus generally appears as sound as in those who have no such disease; however, although the uterus is to appearance sound, yet it may be in such a state as to give the same stimulus of imperfection as if it were entirely removed or not existing. To illustrate this we may bring forward the circumstance of two cocks' combs that were frozen and thrown off as dead sloughs, for I suppose from analogy that the frozen parts were still alive, and if so we may see that a living part may be so circumstanced as to give the stimulus of death to the parts with which it is connected. That the inflammation of the peritoneum arises from the stimulus of imperfection is also evident, because if a man is wounded in trie belly with a sword which has also wounded one of the intestines, if the wound in the abdomen is closed, and unites by the first intention, the wound in the intestine will unite with some part with which it comes in contact, either by extravasated blood or the adhesive inflammation, and no further trouble wall ensue, because the stimulus of imperfection has not been given. But if a man is wounded in the belly, and there is no wound of the viscera, yet if the wound is kept from healing by the first intention, the whole peritoneum becomes inflamed immediately, not from the spreading of inflammation by the continuity of surface, but the consciousness of imperfection in the membrane itself, by which the whole is brought into the same action. It is probable that the uterus suddenly contracting, the neighbouring parts, becoming sensible, as it were, of the loss of a part they have been accustomed to, inflame. Sometimes adhesion will lake place, and a circumscribed abscess will be formed in the lateral and lower part of the belly, and probably the inflammation was chiefly in the round or broad ligament; first there is hardness and pain, then prominence and fluctuation, when it may be safely opened.*

* [Mr. Hunter has fallen into two errors on this subject: first, in ascribing puerperal peritonitis to an ideal cause ; and secondly, in supposing that the constitutional fever invariably arises from inflammation of the peritoneum, ihere cannot, I should think, be the least hesitation in ascribing the inflammation ot the peritoneum which ensues on child-birth to the irritation which the uterus has suffered during that process, for the inflammation is not only sometimes confined to that part of the membrane which covers the uterus, and always is most violent there, but it invariably commences from that point. The fact, however, ot the same cause giving rise to inflammation of the adjacent organs is completely subversive of the imaginary cause assigned by Mr. Hunter, arising from tlie 19* 222 HUNTER'S PRINCIPLES OF SURGERY. Inflammation of Peritoneum after tapping.—A man whom I tapped at the hospital died the third day. I said he died of the puerperal fever. This was smiled at in the hospital, and some were pleasant in remarking on the curiosity of a man being delivered; but a few months afterwards another having the same fate, I convinced them, by dissection, that he had died of suppuration of the peritoneum, which we must admit to happen in puerperal fever. Frequently the inflammation does not go so far as to produce suppuration, and then the patient commonly recovers ; but it often runs the whole course and produces death. It seldom attacks those parts of the peritoneum that are pretty sound, or where the disease is not of long standing; but where the disease has arisen from a bad constitution or diseased viscera, it seldom fails of attacking them, especially in the second or third tapping. Hernia.—The consideration of inflammation of internal cavities leads me to make a few remarks on hernia. We might suspect that the operation for hernia would often be the cause of universal inflammation of the peritoneum, but I believe in bubonocele and femoral hernia it is generally prevented by the sides of the skin of the abdomen being pressed together after the operation. This inflammation is met with after the operation for umbilical hernia, because the edges of the wound cannot be brought together. In this case we should contrive that a portion of the epiploon shall remain at the bottom of the wound, and if it is not protruded 1 think it would be the best way to find it if possible: in this way, by adhesion taking place round the opening, the general cavity would be excluded. Caesarian Operation.—In this operation, and in every other instance where the lips of the wound do not come well together, assistance should be had from art to unite them as closely as possible. If it should be found necessary to use sutures, care should be taken that they do not pass through into the cavity of the abdomen, as by this they would produce effects exactly contrary to what was

" consciousness of imperfection." No such imperfection can be supposed to be felt by the veins, the absorbents, or the ovaries, and yet these parts are frequently inflamed, independently of the peritoneum. Of forty-five fatal cases of puerperal fever which were examined by Dr. Lee at the British Lying-in Hospital, (in all of which was found some morbid change, the effect of inflammation,) the peritoneum and uterine appendages were found inflamed in thirty-two; in twenty-four there was uterine phlebitis; in ten there was inflammation and softening of the muscular tissue of the uterus ; and in four the absorbents were filled with pus. In short, the irritation of parturition may extend to any or all the circumjacent parts within the sphere of ils influence, and give rise to puerperal fever by exciting local inflammation. Local inflammation probably always exists, but the peritoneum is not always that part which the inflammation attacks. The morbid appearances presented on dissection are extremely various, and closely resemble those which arise from inflammation of the peritoneum following the great operations of surgery, as lithotomy, hernia, &c, viz., large effusions of lymph, turbid serum, or pus separately or blended together in different proportions. Pus is not an invariable product of this inflammation, as might be inferred from the text.] PRACTICAL ILLUSTRATIONS, ETC. 223 wished —that of rendering the cavity perfect; for as these continue, suppuration of the wounds made by them will come on, they acting as a seton, by which the exposure of the cavity will be greater, though perhaps, from the irritation they would occasion, adhesions would be formed at the bottom of the wound before they suppurated, which might prevent the admission of air. In a woman in whom I performed this operation, and who died, I found, thirty-six hours after death, that the intestines had adhered o the inner edge of the wound of the belly for the breadth of an nch: the uterus was entirely within the pelvis; but the edges of he wound in the uterus had not closed at all, and a good deal of coagulated blood was found in it I should therefore in future watt until the bleeding had nearly stopped from the uterus before I closed the external wound. ,,„m Bladder.-lt may be said that the bladder be.ng so seldom inflamed after the operation for stone, is an objection <o my supposition that an opening into any circumscribed cavity, by the expoe and consciousnlss of imperfection induced in that cavity is almost necessarily productive of inflammation of that cavity, but here it must be observed that the internal surface of the bladder nartake more of the nature of an outlet than of a circumscnbed ^.taCtting therefore iess ^J^-^

l^lrrtteTwS mu°t rtde'r H ^susceplibie of inflammct"iwS.-It is from the disposition that the cavities of ioints have to fa Unto the suppurative inflammation when anopemng is made nto them that unionby the first intention does not take place. ThTareatest care should be taken to put this in their power if pos- ^5" sVey do not readily run through the regular ^ofi^

mGo* r , .; There are other cavities, besides those of the

* [The lighter and cooler the dressing, in *»-5»J^^^S^ fJS JiJjSd Perfect repose of the organ, an easy P"*?* «** u?a alio th Simplest mod?e of in blood over the wound, is probably the best, ^'V'u^dbe combated at once treatment. If symptoms of infl*™«™*™\£U^^tj, until the by a copious venesection, which should be repeateo, inflammation is subdued.] 224 HUNTER'S PRINCIPLES OF SURGERY. with suppurative inflammation ; nor does the absorption of the fluid which they contain readily take place. Ganglions have been sometimes dispersed by soap p'lasters, and sometimes, although rarely, by electricity. A gentleman was cured of a ganglion on the wrist, which had returned after being dispersed by a blow, by the Balsamum Canadense, applied thick and bound on tightly. I would advise a blow to rupture the sac; but the fluid is soon reaccumulated. For a radical cure, an opening should be made, and this prevented from healing by the first intention, that it may suppurate and heal by granulations. As these are connected with joints, weakness and stiffness may be produced for a time; but this is overcome by motion. Inflammation of the Eye.—I shall consider the eye now as a cavity. Inflammation of the eye often takes place after extraction of the crystalline lens. The lips of the cornea not adhering by the first intention, suppuration ensues, which is followed by a shrinking of the globe. The same effects are sometimes produced when an opening is made to discharge the accumulated aqueous humour, as also when the globe has been suffered to burst spontaneously. This has sometimes happened from accident, the opening into the anterior chamber not closing; but probably these effects only take place where either the crystalline lens or the vitreous humour have been disturbed or lost in part, but more particularly the latter, as the adherence of the crystalline to the processus ciliares would prevent the inflammation extending; but when separated, the posterior part of the eye becomes conscious of this, and suppuration follows. The pus may be seen through the cornea, but no fluctuation can be felt. It is necessary to distinguish between simple opacity of the cornea and the accumulation of pus in the anterior chamber; they may appear similar, and both may be present at one time ; the first maybe of long standing, the last must be recent: an inflammation must have very recently preceded the accumulation of pus. If the progress of the opacity can be observed,—but it cannot always, especially in children,—we may distinguish them: if in the cornea, a dimness may be seen to begin over the whole, and get white by degrees, or it may remain in a point, and remain there only; if pus, it will begin at the bottom of the cornea, and its shape will be semilunar, the straight line being uppermost, and as it advances the line will rise till it comes to the top, and if first seen in this state it is with difficulty distinguished. If the disease is an opacity of the cornea, reabsorption is the only cure, and no operation is to be performed; in the other case, the removal of the pus is the cure. There appear to be two natural modes of cure ; one the absorption of the pus into the constitution, which I have often seen take place; the other is ulceration of the cornea, as in other abscesses, and discharge of the pus. The latter is the worst mode of cure, for the pus, by its pressure on the crystalline lens, may disease it, and an irritation will be kept up by the PRACTICAL ILLUSTRATIONS, ETC. 225 distention, which should be avoided, as the consequence will be the obliteration of the cavity of the eye, as in any other abscess. This, then, leads to an artificial cure, which is by removing the pus at an early period, when we see it will not be absorbed, by an incision like that for removing the lens, by which we avoid the second or natural cure; but it is not always perfect, as we cannot heal the wound by the first intention.* Of the Brain.—I have not seen a sufficient number of cases to determine how far inflammation attacks the pia mater when it is exposed in trepanning, but from the protrusion of brain in such cases inflammation may be inferred, as I have mentioned already. I never saw a case recover where the dura mater had been punctured,f which I attribute to inflammation of the pia mater extending to the brain below. Inflammation of Veins.—The cavities of veins are subject to inflammation, either in consequence of inflammation of surrounding parts, or from themselves taking on the inflammatory disposition and involving the surrounding parts. This inflammation of veins happens sometimes after bleeding, and has been attributed to a pricked tendon or nerve by some, and by others to a bad constitution; but if we consider this consequence arising from bleeding more accurately we shall find that it happens after bleeding in veins where no tendon could be wounded, and when no nerve is in the way, as often as in the others, and frequently in constitutions where there is no apparent want of health, and also where the wound, on bleeding from another part in the same person, probably with a view to cure the former, has healed readily. The manner in which these inflammations come on shows very plainly that they arise from the wound made by the lancet not healing by the first intention, and in different arms we have also the different degrees of extension of the inflammation. In some, suppuration has only spread superficially, the veins and parts below having united, and the inflammation only seated between the vein and the skin, and then it is of little consequence ; in other cases the skin sha appear united, but not close to the vein, so that a small abscess shall

* THvpopium, or the accumulation of pus in the anterior chamber of the eye, is very often the result of inflammation of the whole internal part of the globe, which rarely admits of a cure. When it proceeds from an ulcer situated on the internal part of the cornea, a cure may be expected, particularly if mercury is employed, which causes the effused pus to be absorbed. Neither of these circumstances, however, can justify the surgeon in_ making an opening into the cornea, unless there is at the same time an excessive accumulation of purulent fluid, giving rise to great pain and tension of the g obe. In which cases relief may bi afforded by letting out the pus, although little hope of saving the sight can be entertained from the operation.] ultimate + [Wounds of the dura mater undoubtedly very much aggravate *he ultimate danger arising from other accidents, but are not in themselves universa"y :&*!. On The contrary, numerous cases are recorded of extensive penetratmg wounds of the brain which have recovered without a single untoward symptom.j 226 HUNTER'S PRINCIPLES OF SURGERY. form between the skin and the vein. But when this imperfect union of wounded parts is carried on to the cavity of the vein, then more mischief ensues; the external wound in most cases festers or inflames, then suppurates and ulcerates ; then the vein inflames from being an imperfect cavity, the inflammation extending both towards the heart and from it; and also, for a considerable way, the surrounding parts join in the inflammation. We find in these cases all the different degrees of inflammation in different cases; sometimes it goes no further than the adhesive inflammation, and suppuration is prevented by adhesion being allowed to take place in this part. The veins in such cases are ever after obliterated, and may be felt, after the surrounding inflammation has subsided, like hard cords. But these slighter effects are not always all, and suppuration will unfortunately too often take place. The suppuration has all the degrees of violence and extension. It is often so confined as only to form a small abscess near the orifice; this arises from adhesions having taken place in the vein a little above and below the orifice. In many cases the inflammation and suppuration extend further, adhesions not having taken place; sometimes a very long abscess is formed, and often there is a series of abscesses, following one another in the direction of the vein, between the orifice and the heart; but not always in this course, for we find them sometimes between the wound and the extreme parts. I have seen from a wound in the foot the saphena inflame all up the leg and thigh, nearly to the groin, and have been obliged to open a string of abscesses almost through the whole course. I have almost always found that inflammation has taken place in the larger veins which pass through a part that has been violently inflamed. This disease often happens in horses after bleeding, for the operators do not take proper care to close the orifice in these animals. This has sometimes proved fatal; but whether from the inflammation extending to the heart, or from the matter that is secreted in the veins passing in considerable quantity into the circulation, I cannot say. The method of preventing these ill effects is to bring the edges of the wound carefully together, when the bleeding is finished, that they may unite by the first intention. I would recommend a compress of linen in preference to plaster; for I imagine that the blood itself being applied over the orifice is a kind of bond of union which is more natural than any other application. I have seen more sore arms after bleeding where a plaster has been applied than in any other cases. I have also seen it several times where the orifice has opened a second time and bled again, and has not been properly closed. Treatment.—If inflammation has just come on and not arrived to suppuration, a compress should be applied to produce adhesion of the sides of the vein, whereby the inflammation may be prevented from reaching the suppurative stage. If the suppuration is come OF HYDROCELE. 227 on, let pressure be applied immediately above, to prevent the matter from passing to the heart, by producing adhesion there. Inflammation of Arteries.—Arteries unite by adhesion when their sides are compressed. This we find after the division of the larger arteries after amputation. I never have seen arteries suppurate, and do not know whether they ever do suppurate, nor what would be the consequence. Perhaps it would produce mortification; but I am about to determine this by experiment. CHAPTER XVI.

Theory of the cure simple, but in practice the operation often fails.—Description of the disease;—distinguished from others.—Encysted hydrocele;—its nature;—common to all ages and constitutions ;—disappears spontaneously in children;—rarely in adults;—symptoms;—state of the testicle to be ascertained ;—hydatid ;—scirrhus ;—false membrane covering testes ;—adhesion of testis to cicatrix after puncture ;—former cicatrix to be avoided.—Palliative treatment;—heematocele ; diffusion of blood into the cellular tissue;—suppuration following simple puncture.—Radical cure;—various methods recommended;—object of all;—adhesive inflammation occasionally occurs;— obstacles to its taking place.—Erroneous notions of the mode of cure.— Injection ;—tent;—seton ;—caustic ;—laying open sac ;—violence of the latter method;—all severe.—Practice of removing testicle when enlarged;— doubtful if always required.—Causes of failure of all the above operations,— of each in particular.—Mode of operating recommended;—after-treatment, and consequent symptoms.—On the actions of medicines.—On diseased dispositions and actions.—Of the difference of different parts to heal—Of one disease curing another.

The disease called hydrocele is a very common one ; it consists of an undue secretion of the fluid which moistens the tunica vaginalis testis, and admits of a cure according to the laws of inflammation, suppuration, and granulation, which is the process of a common abscess. Although the theory of the cure of a hydrocele is very simple, yet no disease affecting the human body, and requiring an operation for its cure, has called forth the opinions and pens of surgeons so much as this disease.* The reason of this is easily accounted for ; for they have gone so far as to find that every mode

* [This was no doubt the reason which led Mr. Hunter to enter so fully into the consideration of the subject. " At the time," Sir Astley Cooper remarks, " I was attending Mr. Hunter's lectures, the town was divided in opinion as to the best mode of performing the operation for hydrocele; and so great was the difference of opinion among the students of the different, hospitals, that it was quite ridiculous to observe their warmth on this subject. The operation, by injection, as recommended by Sir James Earle, was not introduced until a few years afterwards, but has since been universally acquiesced in as one of the most simple as well as most effectual remedies of surgery.] 228 HUNTER'S PRINCIPLES OF SURGERY.

of operating but their own has failed, but have not noticed the cause of failure. It was enough for them that they could condemn. They rested contented with having recommended a method which was to them infallible; nor did the condemnation of this favourite method of theirs by others rouse them into an inquiry as to the cause of its failure. The scrotum in man has two circumscribed serous cavities in it, which may become the reservoirs of any part of the blood that may be extravasated, but which are generally in these cases distended with water, forming an aqueous cyst. Besides this, there are other extravasations of water into the scrotum, but they are common to every part of the body as well as it. Each of these cavities is called tunica vaginalis testis, and when either of them is filled with fluid it is called a hydrocele. There are other cavities formed in these parts from disease, like those formed from similar diseases in other parts, and which may be called hydatids. I believe they are more common in these parts and in the ovaria in women than in most other parts, probably from their being glands of a peculiar kind. But every distention of the scrotum with water is called a hydrocele: even water collected in the cellular membrane of the scrotum in anasarcous habits, where it has only soaked through from the parts above, or arises from irritation: this kind might be called diffused hydrocele. This collection in the cellular membrane is often so great as to be diffused into the cellular membrane of the penis, which always produces phymosis, with twisting of the skin of the body of the penis, from the frenum not being so extensible as the common skin. This often proves very troublesome, by confining the urine. The radical cure of this kind of hydrocele will be the cure of the disposition, which is commonly more constitutional than local. But this cannot always be done; and we may then give a temporary relief to the parts where the scrotum is become considerably enlarged, with much phymosis. It then becomes necessary to procure an evacuation of the water, which can easily be done by making small punctures with a lancet or needle in the most depending part of the scrotum, and also, if necessary, at the end of the prepuce. However, some attention must be paid to the state of the patient; for, if very weak and debilitated, mortification may take place at these orifices; therefore the smaller and fewer the punctures the better. Another watery swelling, similar to the above, is described, namely, an anasarcous state of the spermatic cord. This disease I never saw.*

* [Pott and Scarpa have both described this disease, which they represent as consisting of an enlargement of the cells of the spermatic cord, which in process of time, particularly towards the bottom of the tumour, merge in one general cavity, divided by a number of septa more or less perfect. Essentially, therefore, it does not differ from encysted hydrocele of the cord, except in the mode of its commencement.] OF HYDROCELE. 229 The encysted hydrocele is a collection of water in some cyst situated in these parts. This species of hydrocele has been divided into three kinds, according to the situation of the water: first, when it takes place in the tunica vaginalis testis; secondly, when it occurs in the body of the testicle: thirdly, when in the spermatic cord; and, indeed, by the same mode of multiplying species, I could from my own knowledge, make a fourth and fifth, namely, hydatids at the back of the testicle, where the vessels enter, and hydatids on the body of the testicle,* within the tunica vaginalis testis; which last may be complicated with hydrocele of the tunica vaginalis, as I have seen. These two last, as also hydrocele of the cord, are only hydatids in those parts. The hydrocele in the body of the testis must also be classed with hydatids: but this I have never seen. Of those on the outside of the testis I have seen several cases. All these tumours, however, are properly only divisible into two kinds; hydrocele of the tunica vaginalis, and hydatids; for it does not alter the disease whether the hydatids be in the spermatic cord, cellular membrane, scrotum, or body of the penis; it is still hydatid, wherever placed. As the symptoms arising from the testicle being in a state of irritation are different from those of irritation in other parts, so we shall find that the symptoms arising from, and the cure of, these encysted hydroceles will be different from those arising from hydatids in the body of the testicle ; whereas these will be similar to those of the tunica vaginalis testis because in both they have connexion with the testicle. But the symptoms arising from the cure of hydatids not connected with the body of the testicle will be similar to common inflammation in all cases of the disease. The cause of the anasarcous hydrocele is very evident: it arises from a universal disposition to throw out serum: and, from the situation of the part, it becomes a universal detainer of the water as it is descending from the upper parts. In the encysted hydrocele the cause is generally not known, especially of the hydatid kind. However, the hydrocele of the tunica vaginalis often arises from a disease of the testicle; for I have observed that many who are operated on for the radical cure show

* [According to Sir Benjamin Brodie, these swellings commence between the tunica vaginalis and tunica albuginea of the testicle, and not in the proper structure of the testicle as has generally been supposed ; they do not therefore essentially differ from encysted hydrocele of the epididymis, except in being more. strictly bound down by the tunica vaginalis which will necessarily tend to limit their growth, and on this account to obviate the necessity of surgical interference. Simple hydatiform cysts in the body of the testicle are referred to by Dr. Hodgkin. See Med.-Chir. Trans., vol. xv. p. 289. It will scarcely be necessary to remind the reader that the term hydatid 19 employed by Mr. Hunter in the old acceptation. The true hydatid has no connexion with the surrounding textures, and is probably a parasitical animal, endowed with independent vitality and a peculiar mode of propagation, these do sometimes occur in the gland of the testicle in association with malignant disease; but never, I believe, as an original and independent affection.] 20 230 HUNTER'S PRINCIPLES OF SURGERY. a disease in the testicle ; also I have seen several hydroceles that at first were hardly anything but true hydrocele, the testicle hardly appearing diseased, yet in time (viz., a year or two) the testicle has increased gradually, and the water has been diminished so much, that hardly anything was left- but a large diseased testicle, and all this time giving little or no pain. Hydrocele of the tunica vaginalis is common to all ages; it is met with in children, in middle-aged and old men. In children they arise sometimes before communication between the tunica vaginalis and abdomen is completely cut off, so that any fluid from the abdomen can pass down and distend the bag. In appearance this somewhat resembles a rupture ; for when the water is pressed upwards, it makes a swelling close up to the ring, but by squeezing, it can be made to pass up into the belly. In these cases a slight bandage or truss should be worn for some years. Hydroceles are common to every kind of constitution; not more common to the dropsical and anasarcous person than to the healthy, which is not the case with ascites or hydrops pectoris; therefore it is probable they arise from a disease in the part, or are what my be called truly local. They are common in all countries; but they would appear to be most common in warm climates. In general we find them go away of themselves ; in young lads, therefore, in such cases, I never recommend any mode of treatment. In grown people they seldom or never go away ;* I have known only two or three cases in which they have disappeared without the obliteration of the sac. I have tried several stimulants, as mercurials diluted, turpentine, &c, by way of application, but they had not the desired effect. However, I once thought the latter, namely, turpentine, checked the progress of a hydrocele. Even letting out the water simply does not prevent the accumulation again taking place, whence the term palliative cure. Diagnosis.—The encysted hydrocele consists of a bag filled with water placed in the scrotum, sometimes a little higher on the spermatic cord. The principal points to be known or discovered are, whether, when a tumour appears in this part, it contains water; and, if possible, the true situation of that water as respects the testicle: for there is another disease that will imitate this so as to be with great difficulty distinguished from it, which is a diseased testicle simply. Some ruptures put on an appearance somewhat similar to hydrocele, and when the gut contains a fluid, it often gives an obscure

* [Many examples are on record in which old hydroceles have disappeared spontaneously ; an event which is most likely to happen, according to Sir Astley Cooper, when the disease has originated in inflammation; or, according to Sir Benjamin Brodie, about once in twenty cases. However, there is no rule on this subject. As ruptures of the tunica vaginalis from external injury are not followed by a permanent cure, we have no right to suppose that slighter degrees of external violence will have this effect; although something of this kind has frequently been supposed, when spontaneous cures have taken place.] OF HYDROCELE. 231 fluctuation; so that hydrocele is but too often confounded with rupture. Fluids contained in a circumscribed bag are commonly easily made to pass from one side of the bag to another, unless the bag is extremely full and thick in its coats, and then there will be only a gentle receding of the fluid from the side pressed on. This is made plain to the senses by applying our hands or fingers to two different parts of the bag, and pressing those two parts alternately; this is called fluctuation. But solid bodies also, of a loose texture, inclosed in a bag, can be made to recede from pressure, and give nearly, if not wholly in many cases, the sensation of a complete undulation; a feeling which the testicle sometimes takes on in one of its diseases. Therefore, as this body sometimes conveys the feeling of fluctuation of a hydrocele, and as the latter often acquires a hardness like that of the testicle, the difference we might expect to find between the feel of water and of the testicle is in some cases wholly lost. I think that in general a distinction is to be made in the shape ; for I observe that in general when the testicle swells, it flattens on each side, having an edge forwards and backwards, and is not, like hydrocele, of a pyramidal figure, with the apex upwards, passing into the cord towards the ring of the abdominal muscles, and even in some cases passing a little way into the ring, with (in many cases) a slight contraction at the part where it does pass into.the cord. But this cannot be set down as an invariable rule, for the testicle will vary in shape according to the disease and other circumstances ; and hydrocele will also vary in shape according to circumstances, and if it be an hydatid, and not within the tunica vaginalis, it will have less of the pyramidal form, though even then it often retains or acquires that shape; but if flat, it may be suspected to be the testicle. It has been recommended that we should put a light on the opposite side, and see if the tumour has a degree of transparency; but this can only take place where it must be evident from other symptoms, where, namely, the skin is not thickened, and the fluctuation is therefore perfect.* * [There is only one disease of these parts which there is much danger of being mistaken for hydrocele, and that is the medullary disease of the testicle, which it is often very difficult to distinguish from hydrocele. Besides the points of difference which have been noticed in the text, I may observe that the oval shape of the testicle in fungus haematodes is generally marked with some degree of bulging, which destroys the perfect ovality of the swelling; that the cord may be felt perfectly distinct for a greater extent of its course than in hydroceles of equal size ; that the/ee/, although generally pulpy and elastic, is not uniformly so, but softer in some parts than it is in others; that the weight of the tumour is greater than that of hydrocele, and the superficial veins more swollen ; and, finally, that the swelling commences uniformly in every part, unlike that of hydrocele, which begins at the lower part of .the scrotum and gradually ascends. The test by the lighted candle ought not to be despised, especially as it conveys useful information as to the real situation of the testis, and very often gives immediate knowledge of the disease, when, from the tension of the swelling, it is scarcely 232 HUNTER'S PRINCIPLES OF SURGERY. But supposing the disease to be well ascertained to be water, we are not in all cases properly prepared for an operation until its situation with respect to the testicle is exactly ascertained, for the situation of the testicle with respect to the general tumour will vary according as the water is situated. When the water is in the tunica vaginalis, as is most common, or in an hydatid in that bag, the testicle will mostly, if not always be placed at the posterior part of the tumour, and there is consequently but little danger of doing mischief to the testicle by any of the operations, unless adhesions between the tunica vaginalis and testicle have previously taken place, and then the testicle will be confined to the side on which the adhesions are, as well as to the posterior part. If water is contained in an exterior hydatid, then it is not at all certain in what part of the general tumour the testicle may be. Perhaps it is often not possible in such cases to distinguish the situation even by the sensations of the patient, and therefore we must always be on our guard when the situation is not ascertained. If the testicle is found on any side of the scrotum except the posterior, it is more than probable that the water is not within the tunica vaginalis, but in some cyst or hydatid placed contiguous to the testicle, or that some adhesions have taken place between the tunica vaginalis and testicle, cases of which I have seen. If an hydatid is within the tunica vaginalis, and fills up the whole tunic, it will in general be similar to the case of water within the bag itself; but it admits of a variety of complications, which may lead the surgeon into error even in the time of the operation, a case of which I think I have seen. The complication appeared to be the following: water both in the hydatid and tunica vaginalis, which led the surgeon to remove the whole as a scirrhous testicle ; for on opening the tumour and letting out the water, he found another tumour within this, which he naturally took to be the testicle itself, and which of course led to the extirpation of it. On examining the parts after removal, it was found to be simply another cyst of water, with the testicle sound within it, or rather behind it.* There is another mode of complication which the above case gave me an idea of, and which I do conceive I once met with in a patient of my own, namely, that inflammation had taken place over the whole sac, so as for the sac to have become lined with coagulable lymph, similar to what I have seen in other cavities; that this lining at last became part of the sac; but that a part of this lining had separated from it, and the space between the two had become filled with water, as also the general cavity, so that they formed a sort

possible to discern fluctuation. In doubtful cases, it is always expedient to insert a lancet or explorative needle into the tumour previously to the operation of castration.] * [There is reason to believe that this mistake has frequently occurred. The danger, however, of confounding haematocele with disease of the testicle is still greater, although the history of the case, and the suddenness with which haematocele commences, will never fail to point out the difference to the intelligent surgeon.] OF HYDROCELE. 233 of double hydrocele. This case and the anterior hydatid would, I presume, assume the same appearance. We should naturally suppose, when the situation of the testicle is not immediately known, and where the temporary cure has been performed with success, that there could be but little doubt of the testicle being at some other part of the tumour than the part where the wound was first made; but this is not always to be trusted to, for the operation of the temporary cure often becomes the cause of adhesions of this part of the sac to the body of the testicle. This very case occurred to me when about to perform the radical cure, for after having made the first incision on the cicatrix, and cutting through the tunica vaginalis as I thought, I was cutting on the body of the testicle. In performing this part of the operation I suspected all was not right, but did not in the least expect to find the testicle, and therefore cut carefully on till I came to the tubular substance of the testicle. I of course desisted, and performed the operation in another part, at no great distance from the first, as the testicle is not a large body, and I did not require to make a second incision in the skin. There did not appear to be any additional symptoms in this case, in consequence of the wound in the testicle, which seemed to.heal as readily as a wound elsewhere would do. When the testicle is in the fore part of the tumour, either from the water not being in the tunica vaginalis, or from previous adhesions there, and its situation is not known or attended to, and the operator makes an incision on the fore part where the testicle is, like that in the above-mentioned case, and he finds he is cutting on the testicle, and determines to shift his ground, I would advise him either to go lower, or to ward one side with his future incision; but at all events not to go above the testicle, to get into the sac, for there he will most probably find the spermatic cord passing along the fore part; and by cutting through it he may cut the spermatic artery and castrate the patient, or cut the vas deferens, which will in all probability render the sore fistulous. A case of this kind I once saw, where the spermatic artery being cut, the blood escaped into the cellular membrane of the scrotum. This circumstance of the cellular membrane of the scrotum being sometimes filled with blood in consequence of an operation, may at first mislead the surgeon to suppose it is mortification, if he is not acquainted with the cause.*

* [Every species of hydrocele, as Mr. Hunter has remarked, is reducible to two forms, that of hydrocele of the tunica vaginalis, and encysted hydrocele of the cord. The first, or common form of hydrocele, is a true dropsy of the tunica vaginalis, and arises from the same causes which produce dropsies in other situations. The encysted hydrocele of the cord is an adventitious production, which has no existence in the primary structure of the parts, and ought to be classed with serous cysts occurring in other parts of the body. The varieties of common hydrocele depend on the form or structure of the sac, or the nature of its contents. The ordinary situation of the testicle in hydrocele is two-thirds of the way down the tumour at the posterior part; but, as Mr. Hunter has remarked, the tunica vaginalis is liable to every possible form of adhesion, which will necessarily occasion great differences in the position of the 20* 234 HUNTER'S PRINCIPLES OF SURGERY. Of the temporary Cure.—I shall not say much with regard to the palliative or rather temporary cure of hydrocele, as it consists only of the evacuation of the water in the easiest and shortest way, without doing anything to prevent a recurrence of the disease, and is hardly so nice an operation as bleeding. The same care is

testicle and its vessels, as well as of the external configuration of the hydrocele. When the testicle has united to the anterior part of the tunica vaginalis, at the lower part, the vessels of the cord are generally spread out over the anterior surface of the tumour, and become liable to be injured by the trocar. Sometimes the tunica vaginalis presents a honeycombed appearance on its internal surface ; occasionally it is much thickened, especially in those who have resided in hot climates; or converted into cartilage, in which more or less extensive depositions of bone have taken place; at other times it is presented under the form of an hour-glass contraction, which may be either partial or complete, or may, after being partial at first, become complete afterwards. When there are no adhesions, and no thickening of the sac, the hydrocele may attain a very considerable magnitude. I have known several cases in which the apex of the tumour has advanced considerably beyond the external abdominal ring, so that no part of the spermatic cord could be distinctly identified, and the quantity of fluid exceeded from three to four pints; but a case is mentioned by Sir Benjamin Brodie which increased till it hung down to the patient's knees. The fluid of this form of hydrocele resembles that of ascites, that is, it is of a deep yellow colour, and is readily coagulated by heat. It loses its transparency, however, and becomes whitish when inflammation has been present, or becomes of a chocolate hue of various shades when from any cause the smaller vessels of the sac have been ruptured, so as to cause an effusion of blood into the cavity of the cyst: sometimes it contains a number of micaceous particles, consisting of adipocire ; at other times a number of small bodies, looking like melon-seeds ; and occasionally one or more loose cartilages, which exactly resemble those which are contained in the joints. The serous cysts which are developed in the spermatic cord and epididymis, or between the membranes of the testicle, are wholly different from the common hydrocele of the tunica vaginalis, and resemble those which are not unfrequently met with beneath the common integuments of the body, on the surface of the liver and kidneys, in the breast, the ovary, and in other situations. It is possible that they may be produced by the distention of one or more of the cells of the cellular membrane, which a partial inflammation or some other cause may have shut off from their communication with the adjoining cells; but this has not been ascertained. The secreting cyst is extremely thin and loosely attached ; and the fluid, instead of being like that of hydrocele of the tunica vaginalis, is remarkably transparent and watery, and does not coagulate by heat. The occurrence of these cysts on the body of the testicle, or epididymis, will necessarily give a lobulated and very irregular appearance to this organ, and expose it to be mistaken for malignant disease, although this mistake may easily be avoided in general, by a careful examination of the part with the fingers, or by a lighted candle. When they occur high up, they are liable to be confounded with hernia, especially as from their loose connexion with the neighbouring parts, and consequent great mobility, they may easily be pushed up towards the abdominal rin<r, or even through it, and in that case be protruded again whenever the patient coughs. In such cases, however, there is always a visible bulgino- above the situation of the ring, which cannot be entirely dispersed ; besides, hydrocele in this situation may always be distinguished by pushing the tumour downwards, and then feeling for the spermatic cord above the tumour; under such circumstances, no impulse will be communicated to the finger when the patient couohs. Hydrocele of the tunica vaginalis may coexist with encysted hydrocele of the spermatic cord, hernia, varicocele, diseases of the testicle, and hematocele. These complications may generally be distinguished without much difficulty, provided all the circumstances of the ca6e are duly considered.] OF HYDROCELE. 235 necessary as above described to ascertain the situation of the testicle, lest the operator should puncture the body of the testicle, and wounding it, will certainly fail in his intentions with regard to the evacuation of the water, and may be led by his failure to mistake the disease, and suppose it of more consequence than it really is ; not to mention the injury which might be supposed to arise from injuring so sensible a part, though I believe this last circumstance is not of so much consequence as might be imagined, for I know a case where the water was placed in a distinct bag on the posterior part of the testicle, so that this body could not be distinguished from the general tumour by the surgeon, who therefore supposed it to be a hydrocele of the tunica vaginalis, with the testicle in its proper place ; and that he might avoid wounding the testicle, he pushed his lancet into the fore and lower part, but no water came. This he repeated four times, nearly in the same place, with the same effect; and on a further knowledge of the disease it was found that all those four wounds were in the testicle ; yet no bad consequence followed, nor did the patient suffer more pain than afterwards, when the lancet went into the cavity of the bag where there was only water. In such cases the best guides are the feelings of the patient, and not that of the surgeon,—a circumstance to which too little attention has been paid, for a great many diseases may be distinguished by the sensation of the part when in pain. It is well known that the pain felt on squeezing the testicle is very different from that arising from other parts; therefore if it is this organ that is swelled, the sensation arising from squeezing the tumour will be the same in every part, and will be that sensation which is peculiar to the testis ; but if it is a hydrocele, or any adventitious swelling, the sensation will be different in different places, that is, when the part pressed is the testicle, the pain will be such as is usually felt on squeezing the testicle ; and when the watery part of the tumour is pressed, the sensation of common pain only will be felt. From attending to this circumstance only, I have been able to distinguish a hydrocele from a pulpy testicle, when the disease was supposed by other surgeons to be the latter. However, there are cases in which I have still had my doubts about the situation, from the impossibility of pressing on it with sufficient firmness to give the true sensation when the coats are much thickened. The operation for the temporary cure requires an incision not bigger than that made in bleeding ; or it may be done with a small trocar. When the water is let out in this way, it sometimes happens that a vessel is wounded either in the skin, cellular membrane, or sac, which bleeds pretty considerably, and the blood is either diffused into the cellular membrane of the scrotum, giving the appearance of mortification, or extravasated into the sac, and fills it up probably as large as ever. Both these effects from tapping I have seen, but never saw any bad consequences arise from them, the blood being always absorbed. I could even conceive a good consequence to arise from the last, as it might be the means of 236 HUNTER'S PRINCIPLES OF SURGERY. forming a bond of union between the sac and the testicle by the first intention, which I have seen take place partially. This is one of the diseases called haematocele, described by authors; they have also described others of a different kind, but taking place from the same accident; and also some cases of haematocele of the spermatic cord, which I have not seen. A blow has been known sometimes to burst the bag, by which means the water has been diffused into the cellular membrane of the scrotum, and a temporary cure has been produced in this way. The patient, and also the surgeon, have been alarmed sometimes with this case; for blood has been diffused with water into the cellular membrane, which has given the idea of mortification having taken place. I would advise that the operation for the palliative cure should not be performed but at a time when the patient can lie by, as inflammation may come on and produce the radical cure where only the temporary was intended. A gentleman who was usually tapped every six months begged I would do it for him before he went to Paris. I objected, telling him my reasons. He was pleased with them, and postponed the operation until his return, and fortunately for himself, for it actually happened that inflammation succeeded the tapping, which proved the radical cure. In cases where such an occurrence takes place, the wound made by the lancet or trocar has generally healed up in some measure; but inflammation has taken place in the whole sac, and suppuration has come on, and ulceration has led the matter to and through the skin. As the orifice has in many cases healed up, the cause of this inflammation is not so evident as it would be had the sac remained exposed, and the inflammation is therefore not so quick in its termination, and in many cases seems to be stationary, as if suspended between resolution and suppuration. In other cases resolution will take place when the inflammation has been very violent, and when we have been every day in expectation that suppuration would ensue. In this case I would advise you to open the sac, and complete the operation by suppuration.* Of the radical Cure.—As various methods have been practised and recommended to effect a radical cure, it naturally leads me to make some observations on those methods, for they cannot be all equally proper in all cases; however, I mean not to be very particular in my criticisms on those different methods that have been proposed, only so far as to point out different cases where they may be attended with inconvenience, arising from particular circumstances in them; nor shall I mention these different methods further

* [Besides the suppuration of the sac which occasionally follows the palliative operation, particularly in West Indian patients, the sac sometimes mortifies in old people. Sir Astley Cooper has mentioned two cases of this kind, which were followed by death, from which he has judiciously enforced the propriety of keeping old persons to their beds whenever this apparently simple operation is performed.] OF HYDROCELE. 237 than will illustrate my own opinion. I do not even mean at present to recommend one method in preference to another, but only to show the advantages that each has, although they all proceed on the same principle, leaving to the surgeon, and in some measure to the patient, to choose for himself after he has thoroughly considered all the different circumstances of the case ; while at the same time I mean to show that more depends on the mode of treatment after the operation has been performed than on the mode of operating. . The radical cure depends on the obliteration of the cavity which contains the water. There are but two natural methods in which obliteration of the sac can probably take place, namely, by our two inflammations, adhesive and suppurative ; for union by the first intention can hardly take place, though I can conceive it possible in some cases where the operation for the temporary cure has been performed. I have observed that this is a disease which never arises from the constitution, and seldom or never affects it; nor are the parts themselves much affected by the consequence of the disease, namely, the accumulation of water, especially if it is occasionally let out. It is necessary, therefore, that we should be very particular in our method of cure, for whatever danger arises rests in the mode of cure alone. We should always make a material distinction between an operation which is to cure a person of a disease which will probably kill of itself without an operation, and an operation which is performed to cure an inconvenience only, and where the danger is not in the disease but in the method of cure.* The method of cure by adhesive inflammation is union of every part of the cavity with itself; and as the testicle makes part of the cavity, the tunica vaginalis must also unite with it. However, this method is one which I need hardly take notice of, as it is one which very rarely occurs in these cases, and as yet we have no certain method of procuring it without running a risk of the suppurative following it. It is much to be wished that such a method ot cure could be put in practice with certainty and success. That it is possible for such a method to take place I know from experience, and also from the dissection of dead bodies, for we very often find the cavity of the tunica vaginalis entirely obliterated, and fixed to the tunica albuginea; but it is more than probable that in such cases there never had been water in the cavity, and therefore adhesions the more readily took place, these adhesions being a very common

* [M. Dupuytren, in his Lecon Orales, used to remark that <operations> of convenience much more frequently prove fatal than others such for "J*™*" Imputation of the thigh for old anchylosis of the knee, the removal or^d .charge ofTrge bursae, &c; So much so that he was accustomed to decline operating in subcases. Surgeons occasionally allow themselves to be-persuaded, bythe fmportunif.es of a patient, to undertake operations against ^Jh™°™jXng ments loudly declare : surely such conduct ought o be reprobated, as proceeding rimer from culpable weakness or some motive still more reprehensible.] 238 HUNTER'S PRINCIPLES OF SURGERY.

consequence of swelled testicle from gonorrhoea. Perhaps letting out the water, and only keeping the wound open a short time, might just procure the adhesive state, and by allowing it to heal up before the suppurative took place the latter might be prevented; however, I believe the knowledge of this critical time, if there be such, is beyond the power of human sagacity; therefore I believe it would not answer in most cases. Indeed I have seen suppuration follow simple tapping; and admitting we were masters of the degree of inflammation, yet many arguments might be brought against the probability of its success, for we might suppose it not possible for the adhesive to produce its effects universally: first, because it is next to an impossibility to evacuate the whole of the water, and that remaining would be sure to keep some parts separate; secondly, as the tunica vaginalis is much enlarged in such cases, the collapsing of the skin might prevent adhesion taking place at all; thirdly, the contact could not be so uniform as to bring all parts into apposition. I know but of two cases where this method occurred successfully. Observations on the different methods of radical cure.—I believe I am-the first who have taught that the radical cure is performed by inflammation, suppuration, and granulation; it was the general opinion, and I was always taught, that it was by adhesion; but if union took place by adhesion, without granulation, then we should not have had suppuration. The most simple mode recommended for obliterating this cavity consists of making a small opening into the sac, and introducing an extraneous body to prevent union by the first intention in the wound, by which means universal inflammation should take place over the whole surface of the sac. This probably was not thought sufficient to raise an inflammation, therefore it was recommended to throw into the cavity by this orifice stimulating liquors, so as to increase the inflammation; they had not an idea of an imperfect cavity producing inflammation of itself. In very old cases, where suppuraation is but slow in its progress, this mode may be of considerable service. Another method was by seton, which was no more than a double tent, or two wounds instead of one. The ideas annexed to these modes of practice were, that they produced adhesions of the sides of the sac to each other, and also to the testicle, by the first method of union. Great pains have been taken in a treatise published by Mr. Douglas to show the impossibility of the sac collapsing so readily as to unite in every part of its extent. But this is neither the effect one might naturally expect to ensue from the methods put in practice, nor what really takes place in the very cases where they were tried, as is easily known from the symptoms described by the operators themselves, which were plainly those of the suppurative inflammation, though they did not see it in that light. So far was this disease treated to procure adhesions of the tunica OF HYDROCELE. 239 vaginalis to obliterate the sac, and perhaps it was on the same principle that a small caustic was at first applied, and which has been used with success; but in a late publication (Else's) it is recommended on principles very different from the foregoing, for it is there supposed that the whole tunica vaginalis sloughs off and passes out through the opening. But that the whole tunica vaginalis should slough away by this treatment more than when the whole cavity is laid open, is not to be conceived. It is, however, a wellknown fact that the tunica vaginalis often throws off partial sloughs, and in some very old cases may slough wholly away; but it is not to be expected as a general effect. When it does slough, this is owing entirely to the diseased state in which the sac is at the time, and not to any particular virtue in the method of cure. I suspect that after caustic, more than after other methods of cure, there is an appearance very much like sloughing, so much so as very readily to deceive; this appearance is the coagulable lymph thrown into the cavity among the water from the internal surface of the sac in the time of the adhesive inflammation. From the ignorance of the true principles of cure, and the uncertainty of success from the former methods, practitioners were led naturally into the method of opening the whole sac or bag; but most probably they were led to this practice by imitating what may be called the natural cure, in cases where the sac had burst, and a radical cure ensued. It is most likely that the bursting of the sac never happened from mere distention, but from preceding inflammation And suppuration, which might arise from the distention, and in that light is only to be considered as an abscess. And here it will be proper for me to observe, that such a case might lead a surgeon to form an erroneous idea of it; for if he had not been consulted from the beginning of the disease, namely, when in the state of hydrocele, and also had not made himself master of what the disease now is, he might readily suspect it to be a diseased testicle, and might be confirmed in the opinion by the inflammation and suppuration, unless the appearance of these should cause him to suspect it not to be cancerous; but if it does not, he will be most likely led to the extirpation of the whole mass, unless by first laying open the abscess freely he should gain a knowledge of what the disease is. Even then, however, he"might continue to be deceived, for the inflammation having attacked the body of the testicle, he will find it very much swelled, and to appearance diseased, especially if the abscess should not have been thoroughly opened. A case of this kind I once saw, and also the mistake above-mentioned: the abscess was opened, and the testis exposed and condemned; when I saw the abscess and the testicle at the bottom, I suspected what the case was; the testicle was not removed, and the patient got rid of his hydrocele. It is possible that a case of this kind might happen where the disease would not show itself so manifestly; for if the water had been contained in a hydatid, the testicle would not be exposed bv 240 HUNTER'S PRINCIPLES OF SURGERY. opening the abscess, and the whole tumour might appear to be the body of the testicle. In a case of this kind the sick heavy pain and the pain of the back which attend diseased testicle would not be present, nor the pain in the small of the back ; so that if these symptoms were attended to, there might still be a means of saving the testicle. Although this natural cure might have shown the possibility of a cure being effected by inflammation and suppuration over the whole sac, and that very probably no more was necessary to produce it than making an opening into the sac, and not allowing it to heal by the first intention, yet it was certainly not understood, for it was thought necessary by some to open the whole sac, and indeed to make it still more secure by cutting off a part of the sac, or even the whole, which indeed was all that they could, unless they had dissected off the tunica albuginea from the testicle. As this method of operating is much more violent than the others, of course its consequences are more violent; it is, therefore, evidently not to be put in practice to its full extent, if a less violent and as sure a one can be devised. However, do not suppose that I mean to prefer a patient's ease during an operation to his cure. In every one of the operations for the radical cure of hydrocele, the suppurative inflammation is an effect which is pretty violent, and therefore in many cases of thickened sac it produces an inflammation which is absolutely sufficient to kill some parts which are not able to support the actions of life, and which are thrown off in the form of sloughs. Incision, it has been said, is to be preferred, because it gives the operator an opportunity of seeing the state of the testicle, which has been found very much diseased in such cases, so that the operator has thought himself obliged to have recourse to extirpation of it. This is a case which sometimes happens ; but I suspect that, if the symptoms were particularly attended to, we might inform ourselves exactly of it before the operation was performed. Perhaps in most cases it would be right to perform the temporary cure first, which would show the state of the testicle at the time ; and as the sac generally fills again pretty fast, there could be no danger of the testicle becoming diseased during the time of refilling: for in most cases where the testicle is diseased there is an obscurity in the feel; it will give the feel of water in some positions, and in others of more of a solid substance. However, in any of the operations, excepting that by caustic, we might judge, I think, of the state of the testicle as soon as the water was wholly or in part evacuated ; and if the testicle is found of its natural size, there will be no reason for apprehension about it; and if very much thickened, then the surgeon is to act accordingly. But I am inclined to believe that such diseases of the testicle as are generally attendant on dropsy of its coats, and are perhaps the causes of that dropsy, seldom do much mischief. I cannot say I ever saw a cancerous testicle that began by pro- OF HYDROCELE. 241 ducing a common hydrocele, nor can I call to mind any case of common hydrocele, where the radical cure has been attempted, in which the testicle ever became cancerous afterwards. Yet I have known cases where it appeared a true hydrocele at first, and the testicle afterwards enlarged, and by degrees the water diminished, till at last the whole has been an enlarged testicle, and has been obliged to be extirpated. I have often seen the testicle diseased on opening the sac, and it has been generally thought proper in such cases to remove the whole ; yet I imagine it is seldomer necessary than is thought. This disease would appear to be not sufficiently distinguished from cancer, to which I believe it has no real affinity; however, it is possible that cancer of the testicle may be attended with hydrocele. Perhaps this disease may have some connexion with scrofula, for I have seen scrofulous testicles, and have even extirpated them as cancerous. In some cases this practice is right, and it was so in those in which I did it, but it was not intentionally right; for although not cancerous, yet they often become so much diseased and so large that it is absolutely necessary to extirpate them. But still such have an advantage over cancers, as we may be pretty certain of the cure from the operation, which is not always the case where there is a cancerous disposition. If the case appear very dubious, I should recommend an incision, that the state of the testicle may be better understood, and the patient will be equally sure of a cure. , , I shall now mention the causes of failure common to every method of cure, and then the causes of failure peculiar to each. The sac containing the water being membranous, it only can be distended by the water which it contains, and readily collapses and throws itself into folds whenever this distention is taken off; and, as every method of cure requires the evacuation of the water, the membrane will collapse, if not prevented; and this collapsing I find to be the common cause of failure in them all. It is a principle in the animal economy, when any natural internal cavity is exposed, that if any two parts of the cavity are brought together they will unite, but only at the edge next to the exposed surface ; beyond this, if any two parts of the surface are in contact, they will not unite, being excluded from the necessity of union by the union of the edges which are nearest to the exposure, lms part that does not unite then is formed into a cavity capable ot containing a fluid, and of being hereafter filled in that way ; where the sac has been large and not thickened, several such cavities may be formed, each capable of carrying on the disease. Until I understood the above facts, I could not understand why we have recurrence of this disease in the same tunica vaginalis. The first time I saw that a recurrence could take place was in a patient of my own, who died of small-pox whilst under the radical cure of the hydrocele Ihe recurrence of the disease will follow every method which does not prevent the two sides of the sac coming into contact with one another in the time of inflammation. 21 242 HUNTER'S PRINCIPLES OF SURGERY. Of the causes of failure common to theSeton, Tent, and Caustic.— In either of these three methods of treatment, if the water is evacuated immediately,or is evacuated soon after the operation, at least before suppuration has come on, it often happens that the surface of the sac surrounding the orifices shall come in contact with the body of the testicle and adhere, which will immediately exclude all the other parts of the cavity from the necessity of inflaming, suppurating, &c, so that no union of the sac is produced but at the part. I have known a seton inclosed in this way along its whole course, and lying in a canal formed for it, instead of being loose in the general cavity. I have known the same thing happen to the parts when the caustic has been applied: the edges of the sac all round have adhered to the testicle, so that when the slough has come away this has formed the bottom of the wound, which granulated ; the wound filled up, the disease recurred, and required a second operation. I have also found sometimes, where the caustic has been used, that Nature has covered the inner surface of the eschar with new living matter, by which the inner cavity has been made perfect. A patient of mine had a hydrocele in each tunica vaginalis. I applied the caustic to each; when the sloughs came out, I observed at the bottom of each a bluish white surface, while the edges all round were red and granulating. This surface I suspected was the tunica vaginalis not affected by the caustic. I endeavoured to complete what the caustic had failed in; but was surprised to find that I was obliged to push my lancet in half an inch before the water came; when I introduced a tent to prevent its being wholly evacuated. I made a similar attempt on the other side; I introduced my lancet half an inch, and no water came, and I then made a puncture through the sound skin, and had not to go so deep as when the eschar had fallen out. I suppose that when a breach or waste or loss of substance is produced in the outside of any cavity (and probably in every other part) there immediately takes place an irritation suitable to this cause, and this irritation produces an extravasation of coagulable lymph on the inside, to preserve the cavity or part as entire as possible, which it had certainly effected in this case. Probably this is the common cause of failure in the immediate effect of caustic, which was not before understood. We see the same thing take place in-joints ; where that part of the bone which makes part of the joint becomes dead, we find a layer of coagulable lymph laid over the dead part or end of the cartilage, which preserves the joint perfect; otherwise the whole cavity must suppurate. In these cases of joints, as well as in the above, it has puzzled me to know how the layer of coagulable lymph was formed. If in either case death in the part did not go quite to the cavity, but leave a living surface, (no matter how thin, so as it is sufficient to produce a surface by extravasation,) we may then conceive how new matter may be laid on this surface and increase OF HYDROCELE. 243 to any thickness. If we can provide one layer, we can easily make it increase. It is a curious fact, and deserves attention. It is as if Nature was making the same opposition as we should do if a neighbour was endeavouring to niake a way through the wall of our house, and, as we could not prevent his endeavours on that side, we should barricade further on this side, by raising up another wall. To avoid these failures, I have practised and recommended that the tent or seton should be as large as the opening made for the introduction of it, so as to fill up the whole wound, and to allow but little or no water to escape, until inflammation and suppuration have come on; and in cases where the caustic has been applied I have not cut through the eschar, but allowed it to slough off, by which time the necessary inflammation has come on. This mode would seem to give the preference to the caustic; but we find Nature taking all the steps she can to frustrate our operations whenever they are violent upon her, as described above. In some of the cases where the sac has collapsed and united as above described, leaving a cavity beyond it loose, it has happened that the preceding inflammation has gone too far for those cavities to remain in a quiet state, and suppuration has taken place in them while under cure, forming there an abscess which either breaks through the adhesions and opens into the first sore, or makes a new passage through the scrotum, like any other abscess, and a complete cure has been effected. I have reason to believe that from the small opening made by these three modes, old hydroceles are sometimes deprived of the full effect of exposure; and that, though the parts inflame and suppurate, yet when the orifice has become small and taken on the closing process, the sac loses the suppurative disposition, (like the pleura when suppuration takes place,) the surface never having granulated, but simply secreted matter like the inside of a duct; and when the exposure ceases, falls back into the natural state, and the accumulation of water recurs. When the radical cure is to be performed, either by tent, seton, or caustic, it is more proper to do it in one part of the tumour than another. One might at first suppose that the most depending part of the tumour would be the best, as in an abscess; but in fact it is the very worst, because here the inflammation is to follow the operation, whereas in an abscess the opening follows the inflammation. Why this should be a reason for performing it in a different part may not at first sight appear: but it is to be considered that the tumefaction attendant on the inflammation which is to succeed, will not be so great in the part where the operation is performed, if the extravasated juices, which are the chief cause of the swelling, can be allowed to depend; hence the opening will be less liable to close up when made at the upper part of the bag than at the lower, where it would be in the centre of the tumefaction, and would not allow a free discharge of matter, as we really see to be the case on many occasions. To avoid this 244 HUNTER'S PRINCIPLES OF SURGERY. inconvenience, the opening should not be made at the lower part of the tumour; nor at the upper, for the following reason, viz., the water as it increases commonly pushes up the sac into the spermatic cord; therefore the situation of the upper part of the sac is changed immediately on the evacuation of the water; and the sac collapsing and contracting in proportion to the evacuation, its upper part moves downwards, which of course must alter the relative situation of the opening in the sac and in the skin. The opening should therefore be made in the middle of the tumour. Of the Mode of performing the Operation with the Tent.—When the bag is pretty full of water, examine the bag carefully for the testicle. The situation of this being ascertained, grasp the bag in the hand, and squeeze the vyater towards that side where the testicle is not. Push the lancet in until the water comes out by the side of it, and then carry it forward, and enlarge the wound to about double the breadth of the lancet. Withdraw the lancet, but keep the tumour in the same situation, that the orifices in the skin and sac may continue opposite each other, or it will be almost impossible to introduce the tent; but do not press the sac quite so hard, or all the water will come out before the tent is introduced. Introduce the tent with the right hand, and hold it till it swells, when there will be less danger of its falling out. Then put on a piece of sticking-plaster, to secure the whole. The tent may be kept in till the edges of the wound swell, which will be in a few days, and then the tent becomes loose, after which there will be no danger of the wounds closing up, for by this time the alarm will be given to the whole cavity, and the irritation of an imperfect part will be sufficient to prevent the wound healing. I recommend a sponge tent, as it swells and keeps the orifice perfectly open, and as this swelling is greater at the two ends than between the lips of the wound, by which two disagreeable accidents are prevented: the one, the escape of the tent into the cavity of the tunica vaginalis; the other, the escape of the tent altogether from the wound. Of the Seton.—This is to be preferred to the tent, as being more easy to perform. The most easy method is with the common seton needle: holding the scrotum as above, introduce the needle perpendicularly where we know the water is ; lower the end and raise the point, and bring it through the skin about half an inch or more above the other incision. Take off the needle, and apply a piece of sticking-plaster over the wound. A lancet and eyed probe, carrying a skein of silk, is sometimes used, but it does not answer so well. When suppuration is established, the seton may be either left in or removed, according to circumstances. Of the Caustic.—A small caustic applied to the tumour is commonly sufficient to produce the effect, if it acts quite through the sac. In applying it, we should attend to the feelings of the patient, to judge when the sac is deadened by the action of the caustic. OF HYDROCELE. 245 The uncertainty of its acting through all the coverings of the sac has been an objection to this practice by many; and when it does fail in this way, the finishing what the caustic has not effected reduces the operation to the case of a simple puncture. I have before shown another objection also. If the chance of the caustic not penetrating was the only objection, I should prefer the caustic to all other methods of cure for the following reasons: because it removes a small part, which gives a freer passage to the water than a simple wound; and we may produce the adhesive inflammation in the inner edge surrounding the slough before the water is evacuated, which in some degree determines the thickness of that part before the general tumefaction comes on. This gives it a considerable advantage over the puncture or seton, for they produce the general inflammation nearly as early as the local one, which proves inconvenient in many cases by thickening the scrotum at the orifice, which lengthens the passage and almost shuts it up. Besides, if the effects of caustic are produced quite through into the cavity, they excite the suppurative inflammation over the whole cavity before the water is evacuated, the presence of which more readily allows it to become universal. However, the caustic is not always a certain cure, even when its immediate effects are completely gone through, for I once saw a case where the seton had been used first, and on the recurrence of the disease the caustic was employed, yet after this there remained a small sac which required a third operation. The cause of failure in both the first was, I believe, that which I have before noticed of the edges of the opening collapsing and becoming united to the body of the testicle. From what has been said it must appear that the great art in this operation is the prevention of the possibility of a relapse ; to prevent which it is requisite that every part of the sac should be obliterated, for which purpose it is necessary that every part should be subject to suppuration. I have now considered this disease, the precautions necessary before the operation, and the different methods of operating, with their advantages and disadvantages. I have endeavoured to show that every method hitherto recommended has in many instances failed, and I have also endeavoured to show the causes of their failure. It is proper now to consider of some method which shall not be subject to the above mentioned inconveniences. I have of late used the following method of cure, with a view to producing universal inflammation and suppuration of the sac. Make an incision into the sac about three inches in length, and let the whole of the water escape ; then fill it as full as possible with pretty stiff poultice, occasionally introducing your finger to direct the poultice into every corner of the bag; and, lastly, put some lint into the wound to keep the poultice in. The poultice should be be made of linseed meal, and pretty stiff; if it is made into little balls it will be still more convenient. The advantages 21* 246 HUNTER'S PRINCIPLES OF SURGERY. that this method has over the others are, first, that it is simpler than exposing the whole; secondly, the parts are kept universally distended by an extraneous body, so that the inflammation becomes universal; thirdly, the poultice does not become entangled in the granulations as dry lint does ; fourthly, as the parts granulate and contract, the poultice is gradually squeezed out, and only requires superficial dressing during the whole time. With the same intention I have sometimes used lint dipped in oil or lard, which prevents its becoming entangled in the granulations, which without this precaution it is liable to do ; so that I have known it retained in the sore for six weeks, when it was obliged to be removed to allow the sore to heal over.* To prevent inflammation coming on too quickly and causing unnecessary pain, I believe it is right to apply a piece of linen cloth, folded ten or twelve times, and of sufficient breadth to cover the scrotum, first dipping it in brandy and squeezing it dry. Over this apply a suspensory bandage, which should be wetted as it becomes dry. The symptoms following the operation are those common to all wounds, but as there is also a part in some cases concerned in this operation which has symptoms peculiar to itself, it becomes necessary to describe these; this part is the testicle. The testicle is only concerned when the collection of water is in the tunica vaginalis. The symptoms peculiar to it are in some measure those of a vital part; a dull heavy pain is felt, the stomach is sooner affected, and lassitude sooner produced, than in affections of common parts. Besides these, there is one peculiar symptom, that is, the pain in the back attending inflammation of the testicle. This is generally supposed to arise from the nerves of the testicle arising from the nerves of the loins. If this is the true solution of the case, we can only say this is peculiar to this part; therefore out of the common way of symptoms. In less than twenty-four hours the symptoms of the operation will begin: for, although the patient should have no pain, he will soon feel a lassitude, small short rigors attended with restlessness, which show that where this operation of inflammation is going on in the part, though it may not affect the senses, it is yet capable of producing considerable effects on the animal economy, so as very much to effect the vital principle. These symptoms increasing, the scrotum becomes sore to the touch, a greater degree of heat than common arises in the skin, the patient complains of thirst, and at last the diseased part becomes painful, swells, and throbs. The swelling is often very considerable; and, from the pain, this might be supposed to arise from the testicle, but it consists principally of the cells of the scrotum, which being composed only of cellular membrane, and that very ductile, gives way to the extravasated fluid, viz., coagulable lymph and serum. However, the testicle

* [Mr. Hunter afterwards substituted the use of flour, which he dusted over the exposed surfaces] OF HYDROCELE. 247 itself swells and inflames in hydrocele of the tunica vaginalis, especially when that body is laid bare, as might be expected, as that part, or rather its coats, inflame and suppurate. Besides, we have the symptoms which denote affection of the testicle. The future treatment is like that of common wounds, only a suspensory is required, as it relieves the pain in the back. After the parts are healed, the testicle, for a considerable time appears hard and large, and the skin of the scrotum adheres to it. This gradually subsides by the contraction of the granulations, which are the chief cause of it, and by the absorption of the adventitious substance deposited by the inflammation. This natural process may be much accelerated by the use of the mercurial ointment, rubbed on the scrotum, for a month or six weeks.*

On the Action of Medicines.

Before I proceed to make any further observations on particular diseases and injuries, I shall say a few words on medicines, or rather of their action on the human body.

* [There is one capital objection to all the operations above mentioned, which is their severity and danger. Many cases of death occurred, and many more of high constitutional irritation which placed the patients' lives in imminent peril. The operation which is now almost universally resorted to, and which is only cursorily alluded to by Mr. Hunter (p. 238), is free from these inconveniences, at the same tune that it very rarely indeed fails of curing the disease. It was introduced by Sir James Earle, and consists in injecting the evacuated sac with any mild stimulating liquid, such as a solution of zinc, or equal parts of port wine and water, which are allowed to remain in from five to ten minutes, according to the feelings of the patient. A moderate inflammation generally follows this operation, and in a few days the fluid re-collects : after a short time, however, the inflammation subsides, and the fluid is absorbed. The time required for the absorption of the fluid varies from one to six months. Occasionally, but very rarely indeed, the disease returns. It was imagined that this operation effected the cure by causing an adhesion between the opposite sides of the sac. An effect which is doubtless sometimes produced, and probably in all cases to a certain extent, although later observations have proved that universal adhesion of the sac is by no means a general consequence of the operation, which cures by destroying the morbid action of the secreting vessels in some manner which has not been explained. The success of this operation is not by any means in proportion to the quantity of inflammation produced, although a certain quantity seems necessary for the effect. The inflammation arising from injection rarely exceeds the adhesive stage; although this does sometimes occur. Only three cases of this kind are mentioned by Sir Benjamin Brodie as having occurred in his experience, and these three were West Indians, in whom suppuration took place. Occasionally the scrotum sloughs. (See note, p. 236.) Where the operation by injection has failed, the operation by incision may be had recourse to. In children it is generally advisable to have recourse to the seton, using a few threads of silk only, passed by a common curved needle. In encysted hydrocele of the cord the same means may be adopted ; or, what is still better, the sac may be laid open, and the fore part of it cut away. If it be situated on the testicle or epididymis, and of small size, it had better not be meddled with, or it may be simply evacuated, provided it is inconvenient to the patient from its magnitude. The operation by injection does not succeed in encysted as in common hydrocele.] 248 HUNTER'S PRINCIPLES OF SURGERY. The living principle, I before observed, is susceptible of impressions which may be productive of action, either diseased or healthy, *'. e., productive of restoration; each of these may be brought on by medicine. Whatever affects the animal body otherwise than mechanically must be in a state of solution. From our juices being chiefly watery, the solution of many substances can easily be conceived; but they are likewise capable of dissolving earths, metals, &c.; nay, there is, I believe, hardly any substance which is not capable of being dissolved in the human body. Earth, and even iron, is found in animal substances on analysis, which must have been dissolved in the fluids, as well as essential oils, which may be detected passing off by our excretions. Taste is one proof of the power of our fluids to dissolve, for there is hardly any substance capable of stimulating but what will give a taste if applied to the tongue: thus, almost all metals held in the mouth for a little time will give a taste : the same thing most probably takes place with substances applied to the organ of smell. The blood, from its being so heterogeneous a fluid, may have its powers of solution inferred; and as I suppose a necessity of solution of these substances to affect the organs of smell and taste, so in like manner I suppose the necessity of solution, not only for its introduction, but for it to affect the system. Simple water possesses much less power of solution than when combined with some other substances ; thus, by the addition of fixed air it becomes capable of holding earth in solution. From some similar combination perhaps the blood and other animal fluids derive their extraordinary powers of solution. Medicines affect the living principle by their stimulant or sedative qualities only, unless they act chemically, as caustics; they have the effect of irritating or quieting, and these two contrary effects are generally to be found in the same substance, the difference resulting from the difference of quantity; thus, a small quantity of heat relaxes and softens, but a larger quantity will stimulate. A stimulus is what either causes a natural action, or increases one which has already taken place, or excites an action contrary to one present, as by giving an opiate when a patient cannot sleep, &c. Medicines may either stimulate or irritate; such as increase the natural power of acting are stimulants: such as excite new and unnatural actions are irritants. The powers of both will be according to the medicine and the parts combined, for fixed air in the stomach increases its action; in the lungs it destroys action.* The effects of medicine will be different according to the mode of action the parts are in at the time, that is, diseased, natural, or restorative. This is well illustrated by many diseases of the consti-

* [Sir Humphry Davy found that when he attempted to breathe pure carbonic acid the glottis spasmodically closed, from the stimulant action of this gas, so as to render further inspiration impossible; on the other hand, Fodere" has remarked that a too free use of aerated waters will sometimes produce precisely the same effects as the inhalation of the dilute acid by the lungs, viz., giddiness and intoxication.] OF HYDROCELE. 249 tution, as fever, &c, curing diseases in parts which had before been incurable; if the part had not been diseased the effect would not have taken place, for fever deranges a healthy sore. Actions may be, first, of healthy parts ; secondly, action produced by stimuli or irritants on healthy parts; thirdly, action of diseased parts: fourthly, action of stimuli and irritants on a diseased part. Irritants may produce very different effects on a healthy part, or whilst disease already exists ; thus, mercury, by its irritation, will produce diseased action in a healthy part; the venereal poison, by its irritation, will also produce diseased action in a healthy part; but from the application of mercury to a part already affected with diseased action from venereal irritation, an action results different from that which would be produced by the application of it to a healthy part; for from the conjoined action of the two, results the action of health ; but if carried beyond that it may do harm, producing its own specific action. Besides this, it is to be observed that the venereal action, or in fact any other morbid action, may produce a disposition for other increased actions, which may require only the absence of the former disease to allow it to come into action. These consequences are therefore to be distinguished from the original disease, otherwise the mode of cure maybe continued too long, and that which might be curative of the first disease may increase the consequent one. In a former part of the course I mentioned susceptibility, disposition, and action. Can the same medicine have an influence on all these? Will mercury, for instance, destroy the susceptibility and the disposition for the venereal disease, when formed, as well as the action? It will certainly destroy the latter, and we have cases which would make us think it will lessen the susceptibility also; but as to its having any effect in lessening the disposition I should very much doubt; but it may perhaps retard it. A gentleman had a chancre, for the cure of which he used a large quantity of mercury, both by friction and internally, which produced very little soreness of his mouth. The sore at last healed, and from the quantity of mercury which had been useditwas thought that the constitution was preserved; but in a little time discdorations of the skin appeared; for these he drank a quart of s^rsaparilla daily, without their removal; on the contrary fresh ones appeared. I gave two grains of calomel twice a day, and he wafcured. No^ 1 supposl that a disposition for this diseased action might have existed before the mercury was first used, which deposition was by this not lessened, but only retarded, and thecure d dPnot take place until the venereal action took place, which was ?hen cured by the action of mercury the first mercury not prevent, ng the disposition from forming; and it thus appears that what wiU cure the action will not cure the disposition, hence lues often requires repeated courses of mercury. The ultimate effect of [mpTessions, I have already shown, are actions; and I also showed hTd seased actions were thus produced; and here is the place to 250 HUNTER'S PRINCIPLES OF SURGERY. observe, that in the same manner actions may be produced which are destructive of that which is diseased. But disease is not always the consequence of impression, but sometimes of imperfection of parts; thus, there may be a wasting of the body from a want of absorption of chyle from the intestines, or mesenteric obstructions. There is no impression without a counter-impression ; as if one has a pain in the knee from a disease in the hip or loins ; here it would be ridiculous to apply a remedy to the knee, as that is only the effect; yet this is often done.* Medicines have visible and invisible effects. The visible may be divided into two, the constitutional and the local, the former producing the latter. The local are vomiting, purging, &c.; as an instance of the constitutional, the effects of mercury may be mentioned. Their invisible effects are commonly the specific effects, for we find that their curative do not always depend on their visible effects; and indeed their specific effects are often greater when they have no visible effect, as mercury producing salivation in the attempt to cure the venereal disease, bark in intermittents: but others cure by their visible effects. Of Stimulants, Irritants, and Sedatives.—The two former are most commonly used by surgeons, because a want of disposition for restoration is more common than excessive wrong action; and a backwardness to heal is more apt to excite the idea of sluggishness than of excessive or wrong action, though perhaps even the latter may be the case. Medicines given slowly and continued long will produce effects very different to those produced on their sudden application, and thus it is that even stimulants and irritants may produce weakness. On restoration of Action.—In the restoration of action of the whole body, or of diseased parts, attention should be paid to the strength of the parts, or of the whole system, for there may be too much action and too little strength, or too much strength and too little action. Strength and action should be well proportioned to produce good effects. When parts have lost their action for some time, they become weak, as we see in people recovering after drowning. If we do not attend to the degree of strength, we shall often produce irritability by hurrying on action too soon in weak parts. If a man is weak from loss of blood or from famine, his strength should not be tried by too much food, stimulation, &c. When strength exceeds action, then there is room for the use of

* [However unscientific this practice may appear, yet it is often found to relieve the pain, probably upon the simple principle of counter-irritation. If (it is argued) the knee sympathizes with the hip, why may not the hip sympathize with the knee] The principle is not very different upon which leeches are applied to the anus, and sinapisms to the feet, in affections of the head ; that is, certain parts of the body sympathize with each other more readily than with other parts, and on this account are thought to afford the most favourable situations for counter-irritation ; hence blisters to the knee relieve this part by first relieving the hip. The precise meaning of the term " counter-impression" in this connexion is not very apparent.] OF HYDROCELE. 251 stimulants. If the effects of medicines did not extend beyond the point of contact, their effects would be very trifling indeed; but their effects are extended much further by sympathy. This sympathy may be either contiguous, continuous, or remote. Such sympathies as are continuous and similar lose their power by distance only, and medicines acting thus maybe termed local. But it is to be remembered that the remote sympathetic effect of medicines is not always the same as their effect on the part to which they were first applied. If the continuous sympathy was not similar, and if the effect of any medicine on any part thus affected was not continued by that same similar continuous sympathy through that part, how trifling would be the effect of such applications; and how could any application to the surface affect an inflammation which extends to a great depth but by the same sympathy? It is by sympathy that ether, applied to the forehead, relieves headache; applications to the skin of the abdomen, its contents, &c.; in short, if this were not the case no medicine could cure without coming in contact with every part of the diseased organ. On ihe effects of external applications.—The commonly-received opinion respecting external applications is that they enter into the pores of the skin, and so reach the part; and on this idea practice was built. Parts were supposed to be relaxed and moistened by Jie joint effects of warmth and moisture, and on this idea warm Vjaths were used to ruptures and dislocations. In many cases, indeed, very salutary effects were derived from their use; but this cannot be from the cause assigned, for the warmth of a living part is not thus increased ; and a living part may be immersed for ever in warm water without becoming moister, except where the water is in contact. The good effects are produced by the external parts being soothed, and by sympathy the parts beneath lose their irritability, and the natural actions return. In suppression of urine the warm bath is often effectual; not surely because it penetrates from without, but because relaxation is brought on by sympathy. Volatile spirits and vapours have been used with the same idea, but it is well known that water will often penetrate where these will not. Oils are often used for the purpose of restoring stiff joints, perhaps from seeing their salutary effects on rusty hinges; but rusty hinges have greatly the advantage of the animal body, as oil will penetrate into every part of them and wash off the rust, whereas in a stiff joint not a particle of the oil will penetrate. The idea of their penetration has been carried so far as to lead some to prefer animal to vegetable oil, on the supposition that as it had come from an animal it would more easily enter an animal. Essential oils are used as stimulants in rheumatism, &c, but I suppose their effects are only produced by sympathy. Although I do not admit of this mechanical penetration of substances, I have no doubt of their absorption by the action of the proper absorbing vessels: thus, mercury applied to the thigh is 252 HUNTER'S PRINCIPLES OF SURGERY. absorbed and carried through it; but if rubbed on the bubo this can only be affected by sympathy with the skin.* Pressure and Friction.—The ultimate effect of these seems to be similar, namely, stimulating, but from different causes. If pressure is used as a stimulant, it must be gentle: if violent, it will irritate, and produce vesication, as we see in bedridden people. Pressure produces increase of action, by first impeding action, the impediment acting as a stimulus on the part. Friction is more powerful, more active and immediate than pressure, and may be applied to larger surfaces; it does not impede action as pressure does at first, but rouses the parts into action, and excites a warmth in them. Stimulating or irritating medicines render friction more powerful in torpid parts. Fibres, by frequent rubbing, are stretched, and lengthen. Heat, cold, and electricity produce effects not only at the part to which they are applied, but much deeper also. Water as it conducts quicker, is a better vehicle for the application of heat than air. Cold, when applied to the skin, has great and immediate effects. We have two opposite effects from cold-bathing, according to the mode of application and the state of the constitution at the time. By its quick and sudden application the power which the body possesses of forming heat is called up and exerted, and a glow of heat is soon felt on the surface; this is what takes place in a strong constitution ; but if it is too often repeated in the same day, or the constitution is weak, instead of being refreshed, the person is more languid, is chilly through the whole day, the constitution not having sufficient power to restore the heat so suddenly abstracted. Heat would seem to be produced in the vital parts; and it is to be observed that both birds and beasts have warmer clothing over their vital organs than their extremities, which abound more with oil, even in the bones. Action from the application of cold may be diseased, being sometimes the action of weakness; it may also act by sympathy, as cold applied to the back will stop a bleeding from the nose. Applied to the skin it will produce pain in the intestines, and a relaxation of the bladder. In a sprain it is common to pump cold water on the part, as it is supposed to produce action in old sprains. I believe it is not so plainly indicated, except where the constitution is sluggish. Heat pervades all matter: the quality made evident to our senses is here meant; for the matter of heat is to be found more in some bodies than in others, though their sensible heat may be the same. Heat may be native or foreign: the latter I mean to consider here. Heat may be either stimulant, irritative, or sedative. It tends directly to increase action ,» cold, to lessen it. A case explaining

* (Later observations have shown that many of the phenomena of absorption are referrible to imbibition.] OF HYDROCELE. 253 my idea of the necessity of adapting action to the strength may be introduced here. A child, with fever of the putrid kind and sloughs in her throat was very low and weak; she had taken bark, and had been blistered. I was called on account of a large slough appearing on the blister, to which I applied poultices, with opium. It was proposed to apply stimulating applications, which I objected to, on the idea that action had been already beyond the proportion which it ought to keep with the powers of the patient. The warm bath was likewise proposed, and on the same ground objected to ; but it was tried, and my opinion confirmed, by the ill effects it produced. In fact, in such a case as this I should be careful of not increasing action too far; for as it is spared, so must the powers and the strength he preserved. Heat is either applied in a dry or moist state; the first can only convey absolute heat to the part: water or bran in a bladder are the best dry applications. Electricity is the only application, perhaps, which can be said to penetrate, and its influence is very extensive. On Diseased Dispositions and Actions.—I have formerly compared the dispositions of the body with the dispositions of the mind, and observed that dispositions were cured by actions taking place. In some cases the action entirely destroys the disposition; in others it destroys it only for a time, but the disposition is renewed; in others the whole action never destroys the disposition, or if it does, the action goes on without the disposition, as if from habit, till stopped by some unnatural power, as medicine. In the first case, where the action destroys the disposition, it is the action of restoration, as suppuration after inflammation. In the second case the disposition is destroyed for a time, or its power of continuing the action is destroyed for a time, but recurs again because the original cause, whatever it is, continues to exist, and is capable of renewing the disposition again, which again renews the diseased action. This is the case with all periodical diseases as agues, &c, and even some natural actions, as the menses. But whenever the constitution or part is capable of forming the full action of the disease, then that constitution or part is perfectly master of the disease, and it will seldom if ever prove dangerous, excepting it should produce some local effects in a vital part, as sometimes is the case of the gout. Let us take an ague as an example: it consists of three actions, which complete the whole, namely, the cold fit, hot fit, and sweat. If it stops in the cold fit, debility is either the cause, or it takes place; if it stops at the hot fit, strong action takes place which will probably prove a continued fever; if it goes through the third, then it is completed. It often happens that it is not able to form the hot fit, and, as it were, passes over it with sweat, which is cold and clammy, as if the discharge were not common sweat. But such cases approach to dissolution, for the sweat appears not to be the termination of dis- 22 254 HUNTER'S PRINCIPLES OF SURGERY. eased action, but the termination of all action. Fits of all kinds, as epilepsies, are the same ; they are a full action of the disposition ; for such people shall be ill for days before the fit comes on, and after the fit they shall recover perfectly, only feeling a little weak from the exertion. Of the third we have an instance in the lues venerea; for it appears, from experience, that it goes on increasing, till it is either cured or destroys the patient. (See note, p. 90.) Cancer the same, and probably many other diseases. Of the first class there are many more diseases than we might at first imagine. Vomiting would appear to produce the cure of sickness; for sickness is the disposition; and the action, which we must suppose to be the ultimate effect, destroys the disease. Causes may produce a disposition, and that may bring on action at some distance of time, although health may intervene. A young man applied a strong solution of corrosive sublimate for the cure of an itching of the pubis; by this application a violent inflammation was produced. I ordered a wash of lime-water, to decompose any part of the sublimate still adhering, and a poultice of oatmeal and lime-water to cover the parts, with tinctura thebaica sprinkled over it, wdiich gave him much relief. This was continued two days, when I ordered him the bark, to diminish irritability; but the apothecary chose to give him an emetic first, which brought up a great deal of blood from the stomach, for which Dr. Heberden, who was called in, ordered tincture of roses; but this proved ineffectual. Seeing the patient dying, and well knowing the good effects of turpentine in stopping bleeding externally, I gave him two spoonfuls every two hours of an emulsion made wTith Chio turpentine; cold water clysters being also used. He continued for some time very low, and had scarcely any pulse, having lost so much blood; but he recovered, and got strong and fat. He now became dropsical, but recovered from this by the use, first of emetics, and then of squills and turpentine. Here the loss of blood produced not only debility but a disposition to dropsy, which disposition was not at first brought into action, and the patient got fat and well; but the disposition being at length brought into action he became dropsical. It is on the same principle that many acute diseases cure chronic, the disposition being removed by a full action taking place. Should we not therefore attempt to induce this action for a permanent cure? This practice is attempted in some obstructions to the full actions of natural operations, as in the menses: the period of attempt being wrhen the natural effort is made, which is judicious. In intermittents, when there is not full action, perhaps giving a glass of brandy in the hot fit, and sudorifics to complete the termination, might be proper. At present this is only conjecture; but it shall be tried. On the greater or less Disposition of different Parts to Heal.__ Some parts of the body have a stronger disposition to heal in con- OF HYDROCELE. 255 sequence of common inflammation than others. Those parts which have the greatest powers sympathize most and inflame most, as the muscles, skin, and cellular membrane; but we must also observe that these parts have different powers in different parts of the body. Other parts have but little powers of healing, which may be owing to their natural want of powers as tendons, ligaments, bones, &c. These parts often lose their living principle, and be sloughed off, which is often salutary. The cellular membrane is common to different parts, and partakes of the power of such parts; thus, that connecting tendon to tendon has much less power than that of muscle. The sensation of those parts which are backward to heal is very different from that of the muscles and skin, as we should find on pricking them. There is a difference in the power of healing, according to the age. —The diseases peculiar to different ages we have observed, some of which are specific. Those diseases which are common to all are less difficult to heal in youth than in old age. In youth the healing powers "are much stronger than when that period is passed: and this is still more the case with regard to the powers of restoration than in the cure of diseases. Ages I divide into growth, rest, and decline. The powers of restoration may be ranged in the same order, and may be snpposfid greater in a r.hild of two years old than in one which is younger, because it now has strength adding to its powers of growth, the increase of strength being in proportion to its growth up to a certain period. One Disease often cures another.—We have observed that there may be universal sympathy with local affection; now this principle is capable of being reversed. One local disease often cures another, as hernia humoralis a gonorrhoea: and we have a local complaint curing a constitutional, but this local complaint is probably caused by the constitutional, the whole disease centering in one part, as gout, which I have called an act of the constitution. It is on this principle that blisters, setons, and issues are ordered ; the former are useful, but from the latter two I have seen but little advantage. Constitutional diseases may cure local ones; the reason is, no part escapes the constitutional disease. I have seen fevers cure old ulcers, noli me tangere, &c.; which is done by destroying morbid action in the part; the local diseased action and the constitutional producing the third act, or health. Constitutional diseases sometimes cure themselves without taking on the complete action or crisis. When a local disease cures another (which is often the case) it must be by contiguous or remote sympathy, as headache by blistering the arm, gonorrhoea by swelled testicle, &c.; but I have seldom seen the second affection cured by bringing back the former. Local may be cured by constitutional, but may have reflected back on it the same disposition as that from which the constitutional action proceeds. Of ihe Mode of Recovery.—As there is no disease but what has a peculiar mode of cure of its own, and every particular part a par- 256 HUNTER'S PRINCIPLES OF SURGERY.

ticular mode of curing its own diseases, it is necessary to see how far in this case Nature imitates natural principles. We shall first give the original or natural ones, and then show that Nature is always uniform in her operations, and when she deviates is still regular in her deviations. We may observe that a disposition is given at first to particular parts, and that that disposition continues in restoring their own properties, as cartilage grows cartilage, bone bone, &c.; but sometimes she changes the disposition, as the parts become adapted for different purposes, as where a joint is created at the end of an unreduced dislocation. Nature's adherence to her original principle may be exemplified by observing that in the regeneration of bone which was originally cartilage, as the long bones, there when a fracture takes place she begins by forming cartilage, but in the head, where the bone was at first membrane, there membrane is formed. CHAPTER XVII.

Injuries of the head ;—of four kinds ;—concussion;—compression ;—wounds;— want of due support.—Three first to be treated of;—symptoms attending all three.—Concussion.—Compression, from internal or external causes.— Wounds, and loss of substance.—Want of compression from loss of blood.— General remarks on fractures of the skull;—mode of examining them ;—complications ;—treatment.

Injuries of the brain may be said to be of two kinds; one where the imagination is diseased, as madness, which probably arises from many different causes, which we have nothing to do with at present; the other, where it has suffered from some external or internal injury, which is mechanical. This mode of injury may be of four kinds : first, concussion; secondly, compression; thirdly, wounds, and loss of substance; fourthly, want of due compression, which last does not come within our present subject. To these may be added a consequent, namely, inflammation ; but as this may arise from other causes, and is not always the consequence, it only requires to be mentioned. The first may be simple, that is, existing alone, or it may be complicated with one of the others. The first three kinds of injury will produce symptoms similar to each other, but very different from the fourth, as also from what may be called the fifth, or inflammation.

* [It may be observed that the lectures on gun-shot wounds have been omitted, in consequence of their great similarity, both in substance and arrangement, to Mr. Hunters's published opinions on the same subject. It was considered useless to repeat them under these circumstances, especially as they are less perfect in several particulars.] INJURIES OF THE HEAD. 257 The symptoms of an injury done to the brain can, I think, be but two, viz., an increase of imagination, or a diminution. The first is least frequent, and I should suspect arises from a slight cause rather than from a violent one, namely, such derangement as takes place in common madness, fevers, inflammations of the brain, &c, and which may arise from very slight compression. The three first injuries will generally give the appearance of too much repletion. The muscles about the mouth and throat become flaccid, hence laborious respiration; and as respiration must go on, a kind of rattling in the throat is produced, which often works up the saliva into a froth. But all these symptoms will be in proportion to the injury done, and perhaps many other circumstances. The fourth will produce an insensibility, attended with restlessness similar to convulsions or fainting; and I suspect that the fifth produces a delirium, if but in a slight degree. In all cases of affection of the brain, sympathy takes place in the stomach, which produces vomiting ; but I believe that in order that this symptom should take place it is necessary that the senses be not entirely gone, for those who are struck perfectly insensible, I believe, do not begin to vomit till they begin to recover in some degree their senses. Sometimes erysipelatous inflammation of the head arises, and then the patient often feels violent headaches, sometimes approaching to delirium, rigors, &c. In these I suspect that the brain is in some degree affected with the same inflammation, therefore the symptoms are not to be attributed to the immediate effect of the blow. Concussion is always from some considerable violence. It may arise from some degree of displacement or alteration of the texture of some part of the brain, so as to destroy the arrangement on which health, sensation, &c, depend. Compression may arise from accident, or from many other diseases. Those arising from accident may be either immediate or secondary. Immediate, as when a piece of the skull is beaten in upon the brain, or a blood-vessel ruptured, producing apoplexy. The secondary is from slow extravasation, as from inflammation, or the formation of pus. Compressions arising from disease will always be the immediate effect of that disease. They may be said to arise from eight causes; two of which may be called external, the other six internal. The two externals are, when the brain is compressed either by the skull being beaten in, or from the thickening of the bone by disease. The six internal causes are : first, distention of the ventricles by water; secondly, distention of the blood-vessels of the brain; thirdly, inflammation; fourthly, formation of pus; fifthly, extravasated blood, as in apoplexy; sixthly, tumours in the substance of or on the brain. Wounds or loss of substance are somewhat similar. When the substance of the brain is broken in upon, loss of substance may or may not be the immediate effect of the violence. It is the immediate effect, when part of the substance is carried offby the violence; 22* 258 HUNTER'S PRINCIPLES OF SURGERY. but the consequence, when a part is lost in consequence of an opening being made to take off any fluid that is pressing. The fourth species, where there is want of due compression, arises from large bleeding, or where the water is let out which the brain has been accustomed to bear, as in hydrocephalus or spina bifida, which are rare, and which are out of the power of surgery.* Whichever of the three first species of injury takes place, the effects are nearly the same, if the degrees are the same; and whatever are the causes of compression, the symptoms are the same. If we only know that symptoms have arisen in consequence of violence, then it is necessary to know the date of the violence, that we may know whether the symptoms are the immediate or the secondary effects, or both; for they are often attendants on one another. The symptoms of concussion, if slight, are always the immediate effect, that is a more or less immediate loss of sense, &c, which is proportioned to the violence done. Under certain circumstances, the effects of concussion will be more violent than what belongs to the injury itself; for a man who»is drunk may get a blow on the head which, joined with the effects of the liquor, will produce violent symptoms, and may lead the surgeon to do more than is necessary. Therefore it is better to wait until the drunken state is gone off, and the effects of concussion left pure. When there is depression of bone or extravasation, the symptoms of concussion are lost, though it may be at the bottom of all. If the symptoms of concussion have kept up eight or ten days, we may expect extravasation has taken place; if three or four weeks, suppuration. We may know whether the symptoms are caused by blood or pus, by their going off entirely and then re-appearing. If they come on soon after, it is blood; if not for a week or so, it is probably pus. A gentleman for two years after receiving a blow on the skull was delirious. I felt a little depression, and applied the trepan, and took out a piece of bone which had been depressed all this time, part of the internal table of which was absorbed, and pus was lying on the dura mater.t

* [Modern experience has shown that both these diseases are capable of relief from surgery. The operation of drawing off the water, when performed under favourable circumstances and with proper precautions, holds out a reasonable hope of success, and has effected a cure in several cases.] f [The great importance of injuries of the brain may justify a few observations in this place, for the purpose more especially of pointing out the distinction between the symptoms of concussion, compression, and lacerations of the brain, which is a part of the subject which has been only slightly adverted to in the text. Indeed, Mr. Hunter has said that these u three kinds of injury will produce symptoms similar to each other." 1. Concussion—When a severe injury is inflicted on the head, the patient is instantaneously deprived of volition and the power of voluntary motion; the pulse becomes feeble and intermittent, and the whole system labours under a remarkable depression, approaching to a state of syncope. After a few minutes, INJURIES OF THE HEAD. 259 General Observations on Fractures of the Skull.—Fractures of the skull may be divided into three kinds, and these are sometimes

or perhaps several hours, the patient recovers his consciousness; the action of the heart is re-established ; the sickness, with which he was at first affected, passes off, and nothing remains but a severe headache, which may last for several days as a solitary symptom, or else recur at different intervals, upon any occasional excitement. These effects of concussion may of course be variously complicated with wounds of the scalp and brain, compression of the brain, and fractures of the cranium; but very often these complications do not exist; and yet after death no perceptible lesion of the affected organ can be detected, except perhaps a separation of the dura mater from the internal table of the skull, or the extravasation of blood in minute specks in the substance of the brain. In the severer forms of concussion, indeed, the brain is generally lacerated in one or more parts, from whence it is reasonable to suppose that disorganization of a less palpable and extensive kind is also produced in the slighter forms, although it is not capable of being detected by the eye. Now it is observable, that although one of the first effects of severe concussion is complete insensibility, yet this state is soon followed by one in which the sensibility is only impaired, so that it is not difficult to rouse the patient by any sudden and strong impression. Upon being roused, his manner is generally peevish, obtuse, and incoherent, and he instantly relapses into his former state of tranquil lethargy, as soon as he is left undisturbed. There are no indications of paralysis : the pupils contract on exposure to light; the pulse, which at first was exceedingly feeble, now rallies and rises above the natural standard ; the circulation is easily accelerated upon the slightest exertion, and there is very generally an intense headache, which becomes proportionably more severe as the reaction of the circulation takes place and the sensibility returns. The dangers attending this species of injury are twofold. The first arises from the state of collapse immediately following the injury, which may be so considerable that the constitution is not able to make any effectual effort to rally from it. The second arises from the inflammation which may afterwards ensue. Cases of the first description are of rare occurrence and only require that the surgeon should bear in mind the possibility of such an event, in order to guard against it by the administration of cordials whenever the necessities of the case seem to demand these aids to reaction. The danger of inflammation is much more formidable, and will be in general in proportion to the severity of the first symptoms and the rapidity and violence of the reaction. Other circumstances, however, will exercise an important influence on this event, as, for example, the separation of the dura mater from the cranium ; the existence of disorganization or rupture of the minute structure of the brain ; the denudation of the pericranium from the bone; or the patient's being in a state of intoxication at the time of the accident. These circumstances will greatly increase the dangers of his situation, and require a more vigorous adoption of such measures as are calculated to avert inflammation. At first, when the reaction of the heart has taken place, the patient should lose a considerable quantity of blood, so as completely to subdue the force of the circulation; afterwards, for the most part, it is only an occasional bloodletting which is required, and that to a moderate extent. These measures should be assisted by perfect repose of body and mind ; depleting and cooling medicines; cold applications to the head ; a spare diet, and a raised position of the head and shoulders, which should be persisted in more or less for several weeks, even although all apparent effects of the injury have disappeared. It is unnecessary to observe, that the old practice of applying the trephine in such cases is in the highest degree pernicious, and cannot possibly answer any good object. The occurrence of secondary inflammation, at the end of four or five days to as many weeks, should be jealously watched for, and instantly combated by the most vigorous depletion. Such cases generally terminate unfavourably; but 260 HUNTER'S PRINCIPLES OF SURGERY. complicated with one another: first, when the external table is beaten in; secondly, fissures ; thirdly, when the bone is broken off'

happily they are of less frequent occurrence than they were formerly, in consequence, it may be presumed, of the steady antiphlogistic measures which are now almost universally resorted to in the first instance. When, however, these symptoms arise, followed by rigors and the evidences of compression, attended at the same time with a puffiness in some point of the scalp, or a glassy unhealthy state of the wound, if there happens to be one, then the application of the trephine, to let out the matter which is collected between the dura mater and the skull, is justifiable, and ought not to be delayed. Still it must be evident that this operation will be unavailing when the matter is effused on the interior of the dura mater, which very frequently happens in such cases. 2. Compression.—The enumeration of the causes of compression by Mr. Hunter will probably be found to include every possible variety; yet it is to be observed that compression produces different effects, according as it is gradual or sudden ; in the substance or on the exterior of the brain ; in one spot or diffused over a large surface ; or as it is situated at the inferior or superior part of this organ. The slow encroachment of a tumour on the brain does not so suddenly rob the patient of his faculties, as a portion of the cranium suddenly depressed by accidental violence; neither is it of common occurrence for sanguineous effusions on the surface of the brain to produce hemiplegia, although this is one of the most frequent symptoms of apoplexy arising from spontaneous effusions into the substance of this organ. "There is reason," Sir Benjamin Brodie observes, " to believe that pressure is on the whole more dangerous when it affects the lower part of the brain than when it affects the upper part; and it has appeared to me that more urgent symptoms are produced by a given quantity of blood when it is effused into the cells between the tunica arachnoides and pia mater than when it is collected in one mass so as to produce a less general pressure." In speaking, therefore, of the effects of compression, I would wish to be understood as confining myself to that form of the affection which arises from accidental violence. It should never be forgotten that the blow which occasions a fracture and depression of the cranium or an extravasation of blood is likely to produce concussion also, although, as Mr. Hunter has remarked, the symptoms of concussion in such cases will be proportionally less severe, as the cranium has yielded more readily to the cause of fracture. The leading symptom of compression of the brain is insensibility, which is generally much more complete than that which arises, from concussion, and more nearly allied to that of apoplexy, with which in other respects the symptoms of this accident closely correspond. The pulse is oppressed and slow ; the pupils are dilated and immoveable; the respiration is slow and stertorous; and the voluntary muscles are paralysed. Sickness and vomiting do not usually occur, at least in the worst cases, until the cerebral symptoms have undergone some mitigation, and it is observable that the symptoms all disappear the moment the compressing cause is removed, which explains why a copious venesection shall frequently produce a temporary but fallacious amendment. When these symptoms arise from depression of bone, they show themselves immediately after the infliction of the injury; but when they depend on an extravasation of blood, a longer or shorter interval elapses before they come on, depending on the rapidity of the effusion, which will in general be greater in proportion to the celerity and violence of the reaction from the first impression of the accident. Not unfrequently, therefore, the first insensibility is produced by concussion, then the patient recovers, and then relapses again upon the effusion taking place. In other cases, the insensibility, which was only partial at first, gradually terminates in complete stupor, corresponding to the gradual manner of the effusion ; in other cases, again, the patient does not recover from his insensibility until inflammation has set in, and then the two sets of symptoms are confounded together. In short, the symptoms of compression not only vary in degree, but as INJURIES OF THE HEAD. 261 into a loose piece. I have also been told of a case where the symptoms of an injured brain arose, but the skull showed no fracthey happen to be complicated with those of other injuries of the brain ; and it is worthy of remark that the same amount of compression gives rise to symptoms of very different degrees of severity in different cases ; while of two individuals in whom the early symptoms appear to be equally urgent, one may die in the course of three or four hours, and the other may survive for several days; in one the symptoms may wholly subside in the course of a day or two, and in the other continue, at least some remains of them, for several months or even years. Sir Astley Cooper, for example, has related an extraordinary case, in which a total loss of volition and voluntary motion continued for upwards of thirteen months, on which Mr. Cline afterwards operated successfully by removing a depressed portion of bone, which restored the young man to the perfect possession of his intellect in the course of four days. But compression may give rise to other symptoms besides those which have been mentioned, as, for example, pain in the head, general convulsions, furious delirium, partial paralysis of particular muscles or sets of muscles, and various states of the pupil. The pupils, as I have already mentioned, generally remain permanently dilated ; sometimes, however, they remain permanently contracted, or contract and dilate as usual, although in other respects the patient may be in a complete state of insensibility. Dr. Hennen has related a case in which the admission and withdrawal of light operated differently to what it usually does ; and Sir Benjamin Brodie has referred to cases in which the two pupils were in opposite states, or in which they dilated and contracted independently of light >nH darkness. The loss of one entire class of sensations, as of speech, smell, taste hearing', or sigui, 10 nut voij unvuiiimun, vn iue arrtecuon may Be even still more partial, as, for example, a ptosis of one eye, a paralysis of one arm or one side of the face, the destruction of the sexual powers, or the loss of memory, which may be either of recent or of remote events. In some of these cases dissection has disclosed some local cause of pressure, while in others the removal of a depressed portion of bone has immediately removed the symptom, so as to leave no doubt on the mind as to the real cause which produced it. In many instances, however, it is only possible to offer a conjecture, derived from general analogy and the particular circumstances of the case, guided by the knowledge which we possess of the functions of the different parts of the brain, from all which it would appear probable that these partial lesions are sometimes due to disorganization of, or pressure on, certain districts of the cerebrum, from whence the nerves to the paralysed parts are specially derived. However, as Sir Benjamin Brodie has remarked, " it is difficult to conceive that pressure on the brain should exist in so great a degree as completely to destroy a complete class of sensations, and at the same time be so partial as not to affect any other function of the nervous system. On the other hand, it is also difficult to regard these as the effects of concussion of the brain, since it is one of the characteristics of concussion to produce no more than a diminution of sensibility, and that diminution, instead of continuing for months or years, is completely relieved in the course of a few days, and probably in a much shorter space of time." The most common situation in which blood is effused in accidents of the head is between the dura mater and tunica arachnoides, especially towards the base of the brain. It may occur, however, between this last-mentioned membrane and the pia mater, or between the pia mater and the brain, or in the substance of the brain itself. It may also occur between the dura mater and the cranium, whenever the connexion between these parts has been destroyed by the violence of the injury. It is, however, to be observed that considerable effusions of blood rarely occur in this last situation, except when the cranium has been fractured in the direction of the middle meningeal artery, and the artery has been ruptured in consequence. , The treatment of compression arising from depression of bone will be spoKen of in a future note ; but where compression arises from extravasation ot blood, 262 HUNTER'S PRINCIPLES OF SURGERY. ture or fissure; and on removing a portion with the trephine, the inner table was found beaten in, the external table being perfectly

the same general principles must be followed as in cases of concussion, both to prevent any further effusion and to obviate the danger of inflammation. The question however arises, whether any operation can be beneficial for the purpose of giving an exit to the effused blood ? In answer to which it may be replied, that as a general rule no operation can be beneficial in these cases, both on account of the difficulty of ascertaining the precise seat of the effusion, and the impossibility in the great majority of cases of reaching it when it is discovered, When, however, a blow has been inflicted over the meningeal artery, and the symptoms of compression are not only not relieved by venesection, but gradually become more urgent, it will be extremely proper to give the patient the chance of the operation, which will also be proper in other cases where the seat of the injury is well marked and the stupor is hourly becoming more alarming. Unquestionably it would be unwise and unwarrantable to resort to an operation too hastily, but under the circumstances which are supposed an operation will scarcely be supposed to add much to the danger of the case, at least the operation of dividing the scalp in order to ascertain whether the bone bleeds freely, or whether there be any fracture. If the bone does not bleed so freely as it ought, or if there be a fracture, these are justifiable grounds for perforating the cranium; and the surgeon will be further justified in puncturing the dura mater if he finds an accumulation of blood beneath that membrane pressing on the brain. It ought, however, to be remarked, that it will always be expedient to remove the cranium extensively whenever the trephine is resorted to for this urpose, or for affording: an escape to pus, as without this, is done only half the enefits of the operation will be obtained. 3. Wounds of the Brain and Membranes.—The peculiar danger of wounds of the brain and its membranes arises, in the great majority of instances, not so much from the immediate effects of the injury as from the extensive and intractable inflammation which afterwards follows, giving rise to effusions of pus, disorganization of the substance of the brain, and hernia cerebri. When the head receives a severe concussion, the brain is liable to be lacerated, particularly towards the base, in consequence of the inequalities of the cranium at that part; and the symptoms in such cases will necessarily be complicated with those of concussion as well as with those of compression : but when the brain has been simply incised or punctured, very often no symptoms whatever arise to indicate that the bodily or mental functions are in the least degree impaired ; indeed this absence of symptoms is sometimes very remarkable, and extends to cases in which considerable portions of the brain have been lost, or foreign bodies been lodged in it. Wounds of the brain, however, are always dangerous, and it is not to be supposed that there can be an extensive destruction of a part so important as the brain without immediate death, or death in the course of a very few hours. A confusion of intellect beyond that which simple concussion usually produces, and twitches of the muscles of the extremities, are diagnostic marks by which (as Sir Benjamin Brodie has observed) these cases may sometimes be distinguished. The same author also observes : " I have not been able to discover, among all the works which 1 have consulted, a single instance of recovery from a wound of the posterior lobes of the cerebrum, of the cerebellum, or medulla oblongata; and in the great majority of cases in which a cure has taken place, the injury has been confined to the frontal hone, and that part of the brnin which is covered and defended by it." It is unnecessary to observe that the general principles of treatment which have been already pointed out are equally applicable to wounds of the brain, and must be persevered in with the most watchful assiduity. The local treatment resolves itself into the management of fracture, which will be considered in an ensuing note. I shall only, therefore, further observe, that the most judicious surgeons of the present day unitedly concur in the wisdom of forbearance, and in not attempting to extract foreign bodies, unless this can be done with the most perfect facility.] I INJURIES OF THE HEAD. 263 sound. I have seen several instances where the external table was beaten in, and the inner table not hurt.* Depression of the external table may be complicated with extravasation or concussion, and may become the cause of extravasation or of the formation of pus. Fracture may be complicated with fissure, that is, fissures often run from the fracture a very considerable way along the skull. Where the external table only is beaten in, it is owing to the meditullium being thick and spongy, and allowing the external plate to sink into it. This is generally done by a small instrument with a good deal of velocity, as the edge of a horse's shoe. Every violence that can produce complete fracture must cause more or less depression, though it may not be very visible; and sometimes, if the force has not been very great, the piece may be returned again into its position immediately. Besides, the inner piece is always broader than the point where the violence has been applied on tire external. All fractures of the skull may be called compound ; for if not so naturally, they are made so by the removal of the scalp. They differ widely from fractures in general in other parts, as healing the parts is only necessary in fractures of other bones, but here we have to prevent the mischief arising from the broken bone to parts essential to life. Fractures of the skull of themselves produce no symptoms respecting the brain, only those of a broken bone ; but when they are complicated with other effects, then symptoms arise accordingly, more or less according as the fracture is greater or less. There may be bleeding at the nose and ears when the fractures must be running over these parts, but they may occur without a fracture of these parts, and there are symptoms of other injury besides fracture. When complicated with concussion, the symptoms of this will be less according as the fracture is greater, for it is from the bones not giving way easily that the head is violently and quickly moved so as to produce concussion. These effects will be according to the weight and velocity. When the weight is great and the velocity small, we shall have more concussion than with a small weight and great velocity : hence from gun-shot wounds we seldom have any concussion. In cases of fissure only it may admit of a dispute whether we are always to trepan. If there is no symptom of an injured brain,

* [Dr. Hennen has given an account of a case in which the internal table of the. skull was splintered, and at one part driven more than half an inch into the membranes of the brain, although there was not even a fissure of the external table. Cases of a similar kind are preserved in almost every museum, and are easily accounted for by the greater brittleness of the internal table. Of course the same cause will produce similar effects in ordinary cases, so as to render it impossible to ascertain the actual amount of pressure which exists in any given case from mere inspection of the external fracture. In children the bones generally are more tenacious than in adults, in consequence of containing less earthy matter. Hence the cranium may be depressed or indented in them without being fractured, just as a tough or green bough will yield to a force in a very different manner from a dry stick.] 264 HUNTER'S PRINCIPLES OF SURGERY.

certainly it will not be necessary. It may not be necessary even when attended with symptoms of an injured brain, for the injury may only be from the concussion, and we never trepan in a concussion. However, as we cannot tell for certain at the time whether the symptoms arise from concussion, compression, or from extravasation of blood, it may be more advisable to trepan, as the operation can do no harm. In cases of depression of the outer table it would also be unnecessary to trepan ; but it will be impossible to say that it is certainly a case of this kind: for, though there may be no symptoms of an injured brain, there may be depression of the inner table, which may do mischief afterwards. In young people there may be fracture with depression which may cause no bad symptom at the time, but as the patient grows up bad symptoms may arise, probably from this cause, that there is not sufficient room for the natural growth of the brain. In all cases of violence attended with compression, either from fracture or not, the trepan is absolutely necessary ; but we cannot always promise relief from the operation, nor can we always apply it where it is necessary. When compression is by bone, and its situation known, and the situation is a proper one for trepanning, there is no difficulty; but when the compression is by blood or pus, and there are no external marks of violence, then it is more puzzling. However, rather than let the person die, one would trepan somewhere or other; and if this did not answer, one would not stop here: for I have seen a collection of matter on the opposite side to that on which the blow was inflicted ; yet this is a case where one would promise but little encouragement, there being but little chance of success. Even when we have external marks of violence to guide us, and do trepan, yet this is often not sufficient to free the patient from the compression, for these fluids are often formed between the dura mater and the brain when none is found between the skull and dura mater. The dura mater must not, however, be perforated without good grounds; we should be as certain that there is fluid contained under the dura mater as we were certain of the necessity of applying the trepan in the first instance. In all cases where I have seen the dura mater wounded, it was by a crucial incision, and the patients have all died. When it is necessary to open the dura mater, I would recommend making a simple incision, for this would be more likely to heal by the first intention, and we could then move the edges to one side, and see if there were any injury below. Whenever I have seen the dura mater opened, the brain has worked through the opening, and the patients have died.* This was the

* [As hernia cerebri may occur simply from the support of the cranium being removed, it will a fortiori be more likely to occur when the dura mater is removpd also. I should remark, hor,ever, that hernia cerebri does net necessarily ensue under these circumstances. It may be proper to observe, that the treatment of this disease consists in the INJURIES OF THE HEAD. 265 case with a Mr. Cooper, whose dura mater I opened with a crucial incision on account of the state of parts beneath: he died, and I think it is probable I killed him, by opening the dura mater. Patients, under these circumstances, might probably have died independently of the opening, but this I think would certainly kill them. Fractures very rarely run through the base of the skull where operations cannot be performed ; but if the bones of the base of the skull are only fissured, it will be of sufficient service to trepan on the fissure as low as we can follow it. I have trepanned once below the insertion of the muscles of the neck, and with success. Trepanning on sinuses has been condemned, but it can do neither harm nor good if the blood is between the dura mater and pia mater; if there is only a depression on them it can only obstruct the sinuses, and not affect the brain. An incision is sufficient to examine for a fracture if made sufficiently long; and if a fracture is found, it is to be followed to its full extent: but where it is found necessary to trepan, it will be proper to remove the scalp, and do it freely, for an operation should have no incumbrance which we can prevent. We should scalp carefully, lest there should be some loose pieces of bone underneath which we cannot see, by which otherwise we might plunge into the brain; and yet I own I cannot always call to mind this caution at all times when operating.* It has been recommended lately, after trepanning, to put the scalp down again, and unite it by the first intention; but I doubt whether we should be able to bring the angles perfectly together; and if not, part of the dura mater must be exposed, and must suppurate. A fungus is very apt to arise from the dura mater. Why this should be more than from any other part I cannot say. A poultice is the best application after either scalping or trepanjudicious application of pressure until the fungus is repressed below the level of the dura mater, which then heals over it and prevents its reproduction. This plan generally succeeds, although the old method, consisting in the removal of the surrounding bone, or of the fungus itself, almost invariably failed. The danger of hernia cerebri being formed when the cranium is removed may justly be urged as an argument for not having recourse to the operation of trephine without the most satisfactory reasons, to which may be added, the still more alarming risk of inflammation and sloughing of the dura mater from accidental violence inflicted by the trephine, or from the mere effects of simple exposure. The fact also of a portion of the cranium being left undefended after the recovery of the patient, should not be neglected in estimating the dangers of this operation, which unquestionably are very considerable.] * [It is impossible to help being struck with this confession, so characteristic of the love of truth and candour which Hunter possessed. Indeed, the same remark appears to me to apply to all the preceding observations, in which may be traced a hesitation and forbearance of judgment uncommon to the author, as if he had not fully approved of the existing rules of treatment, although he had not yet gone to the extent of substituting others in their stead.] 23 266 HUNTER'S PRINCIPLES OF SURGERY. ning, because it always admits of immediate removal, and keeps parts in an easy agreeable state.*

* [No part of surgical treatment (with the exception perhaps of aneurism,) has undergone such important amelioration as that which relates to injuries of the head. Whoever will look into the writings of the period when these lectures were delivered will be astonished at the officiousness of surgeons in counteracting the restorative efforts of Nature by their rude interference, and converting into complicated wounds what were simple in their origin. Hunter was unquestionably less infected with this evil than most of his contemporaries, but still we cannot but observe the influence of this spirit in the directions which he has laid down for the treatment of fractures of the cranium, for which reason it will be necessary to guard the reader against drawing false conclusions on this important subject. The propriety of these observations will be apparent from considering the cases in which Hunter thought the application of the trephine was justifiable, viz. 1, in young children in whom there was depression without symptoms; 2, in cases of depression of the outer table only; 3, "in cases of fissure only it may be more advisable to trepan, as the operation can do no harm,-" 4, "in all cases of violence attended with compression, either from fracture or not, the trepan is absolutely necessary," and if blood is not found on one side, to trepan on the other; and lastly, in fractures of the base of the cranium. Now it is to be observed that there is as much, if not a much greater, difference between simple and compound fractures of the cranium as there is between simple and compound fractures of the thigh ; consequently, nothing can be more unadvisable and rash than to convert a simple fracture into a compound one, unless the urgency of the symptoms is such as imperatively to demand interference. In regard, therefore, to simple fractures of the cranium, it may be laid down as the general rule of practice never to interfere without the strongest reasons for so doing, nor even then until a reasonable time has been allowed for the symptoms (which may depend on concussion,) to subside, and depleting measures been freely employed. Under such treatment the symptoms will often disappear after a short time, and the dangers of subsequent inflammation be infinitely lessened. Nothing surely can be worse than the attempt to anticipate the symptoms of compression by resorting to the trephine. And in regard to compound fractures of the cranium the same rule is to be observed. If there are no symptoms, the surgeon should desist from any interference, and endeavour, to the utmost of his power, to procure union by the first intention. If, indeed, the depression is very considerable, it may be advisable to elevate it, although there are no symptoms at the time; but if there are symptoms, it will be right and proper to do so in all cases. The same principle should guide the surgeon in the extraction of splinters of bone and foreign bodies, and restrain him from making the attempt unless his object can be accomplished without adding to the irritation of the injury. It is scarcely possible to imagine a case in which an operation so near the basis of the cranium as the author has described can answer any useful object.] OF THE DISEASES OF BONES AND JOINTS, ETC. 267 CHAPTER XVIII.

OF THE DISEASES OF BONES AND JOINTS J OF FRACTURES, DISLOCA- TIONS, ETC.

Bones liable to all the diseases of soft parts.—Death of bone.—Caries.—Diseased actions; — ulceration; — induration. — General treatment of diseased bones.—Accidents to bones; simple fracture;—principles of treatment;— period and mode of union;—false joints.—Inflammation of bones;—treatment.—Suppuration of bones.—Compound fractures ;—treatment;—communicating with joints.—Question of amputation.—Fracture of patella, olecranon, and outer ankle.—Suppuration in bones;—spina ventosa;—necrosis;— treatment.—Of the contraction of diseased joints___Sprains ;—treatment.—Dislocations ;—observations on their reduction.—Formation of new joints.—Accidents andinflammation of joints.—Loose cartilages.—Anchylosis.—Diseasestof joints.—Wasting of muscles.—Exfoliations and necrosis;—treatment, by actual cautery.—Extraction of sequestra.—Rickets.—Mollities ossium ;—treatment. —Exostosis;—treatment.—Exfoliations of cartilage.

Bones have been very much considered separately from other parts in their growth, structure, and diseases. Bones being less subject to changes after death than the soft parts, are therefore more favourable for the explanation of their diseases after death, such as ulceration, tumours, &c.; and diseased bones of all kinds may be picked up in church-yards. The bones, in their causes of disease, in many of their diseases, in the terminations of these, and in their restoration, are similar to the soft parts. They are susceptible of the different inflammations and their consequences, but they are more backward to heal, forming fistulas; in their specific diseases also they resemble the soft parts. But, unluckily for bones, they can hardly swell; nor can their coverings swell without its being immediately suspected as venereal, so that mercury is often given to the detriment of the patient. Nor can they require a different treatment, as regards their vital power, from the soft parts, though they may in the mechanical part; but it will be found that they require a different mechanical treatment only in consequence of their solidity. The hardest bones are most liable to venereal affections; the softer to scrofula ; but the surrounding parts very often partake of their diseases for very wise purposes. Their diseases do not so readily recover as those of soft parts, as the restoring powers are much more weak and tedious in their operations. This slowness is probably owing to an indolent disposition and weak powers. This may, in some measure, arise from the earth in them being a part not possessed of the living principle; yet we find that the hardest bones are cured the soonest; but this is when there is exfoliation, which shows they are more ready to die, and, consequently, to exfoliate. 268 HUNTERS PRINCIPLES OF SURGERY. Their diseases are often very serious, in consequence of our ignorance of the extent of disease, as well as of its nature; for though, from an increase of size or a fistulous opening, we may know the bone to be diseased, still we obtain very little information as to its nature. Death of Bone.—Bones often lose their life from becoming detached, and their surface being either exposed to the air, or to matter surrounding it. The reason of this is, that bones receive most of their nourishment from the surrounding parts, as from the periosteum; therefore it is natural to suppose that the surface at least will become dead when this part is removed. This may be observed on the projecting end of a stump. The harder the bone, the more ready it is to lose its vital principle by exposure. Sometimes the external surface dies easier on being laid bare than the internal: this is the case in the skull; the external will often exfoliate without the internal.* Caries.—Death of the exposed surface makes a material difference in the appearance of ulcers of the bone, and they have been classed accordingly. In one case surgeons found the surface of the bone dry; in others moist, and covered with matter; hence the distinction of dry and moist caries ; but this arose from ignorance of the disease. When the bone is entirely dead, then there is dry caries; but in the moist the bone is inflamed and ulcerated, and furnishes a discharge, not being dead. When it wras perceived that the dry caries only exfoliated, the actual cautery used to be applied on the idea of drying the moist caries ; but this was done without knowing the principle on which it was done, viz. that of entirely destroying the life of the bone. By caries I should understand a rotten bone, and by a rotten bone a dead bone. But the distinction between a diseased bone and a dead bone has not been sufficiently attended to, for the term caries has been commonly applied to a bone in the state of an ulcer, and also to a dead bone. Now a disease must always be in a living part, whether soft or hard; but the same term applied to the two different states of bones can give no just ideas of the disease which it is intended to designate, for that which is commonly called caries is, strictly speaking, an ulcer in the bones ; but ulcers of the bones are as different from the death of these parts as ulcers in soft parts are different from common mortification. Diseased Actions of Bone.—Bones are very susceptible of diseased actions and dispositions, and sometimes a very slight accident will convert a disposition into an action, as in scrofula; and this may again be increased by the part of the bone which is injured ; thus, in the case just related the effect is most considerable when it happens at the end of a bone forming part of a joint. The situation, with respect to the body, is also a cause of retardation in healing, as it is in the soft parts. * [The reason of this is that these two layers are nourished by two different sets of vessels.] OF THE DISEASES OF BONES AND JOINTS, ETC. Ulceration.—Ulcers of a bone are exactly the same in their immediate causes as those of a soft part, and in some of their effects also, the difference not being that of the disease but of the structure. Bones admit of every mode of absorption that the soft parts do. The most common cause of absorption in them is pressure ; whatever makes an unnatural pressure gives a stimulus for the removal of the bone. Bones admit of being absorbed from debility, or want of power to support themselves; but this I believe only takes place in newly-formed bones. Induration.—It does not appear that ossific inflammation takes place in the parts pressed, so as to make them firmer and harder, as in the soft parts. If bones were rendered harder they would have less power, and therefore would be more liable to death. However, there is often a thickening or running up of the bone all round, as in old dislocations, so that a new joint will be formed. Diseased bones communicate their disease to contiguous parts; most commonly to the nearest, as the periosteum ; when near to the joints, to the ligaments or cartilages. General treatment of diseased Bones.—This I shall refer, as much as possible, to the treatment required in soft parts, which is very similar, though the slow action in bones renders it more tedious, and requires a somewhat different method of cure. If an abscess is seated in the soft parts, and also in the bones, that in soft parts will readily be recognised, from the difference in its appearance and feel from any of the surrounding parts; and it will in general approach the skin very soon, which, however, will depend very much on the nature of the disease and of the soft parts. The abscess in the soft parts will generally make a passage for itself, without the necessity of an artificial opening. But this is not so in bone ; if a spontaneous opening takes place, it is not sufficient for a cure ; therefore the trephine is often necessary; or it maybe necessary to destroy the living principle in the bone, and then the actual cautery will be necessary. To kill the soft parts the caustic is sufficient; but the actual cautery is required for bones. Of accidents to Bones.—The effects of accidents which hurt a sound bone are never to be reckoned as disease while it retains the actions of restoration natural to the animal body. Injuries done to bones are of two kinds: one, simple injury without exposure; the other, injury with exposure. One simple injury is a bruise; another simple injury is a loss of continuity, as in a simple fracture. The union of the bone in simple fracture is exactly similar to the healing of a wound in the soft parts by the first intention; but here adhesive inflammation is unnecessary, though it generally happens from the irritation, and then adhesive inflammation is substituted for union by the first intention. Simple fractures'.—A simple fracture is a solution of continuity, generally with laceration of the surrounding parts, attended often with splinters of bone attached to the soft parts, or loose. The space between the broken surfaces of the bone and other parts are 23* 270 HUNTERS PRINCIPLES OF SURGERY. first filled with extravasated blood from the ruptured vessels. This blood coagulates, and in time becomes vascular, as in the same mode of union in soft parts, forming a callus.* Then the arteries and absorbents, by their action, model the part, and form it into a cellular substanee, in which the arteries deposit calcareous earth. It is first formed into cartilage, and then into bone. Adhesion of the detached splinters also takes place, interstitial absorption making them softer, and less pointed; and this takes place not only in those which are attached to the soft parts, but even in such as are entirely loose. (This was shown in a thigh-bone, in which one of the splinters had been tnrned quite round on its axis, and adhered by its outer surface to the bone.) Therefore these pieces must retain the living principle, and probably only this, while those that remain attached have more. I never examined a compound fracture without finding some of these loose pieces, which shows they must be common. Their union must be similar to that in the transplanting of teeth. Callus.—The modelling of the callus to the parts in the neighbourhood is very evident in ribs that have been fractured, for on that side next the lungs the inequality is very inconsiderable. Whether the modelling in these cases is purely from the mechanical pressure of the lungs, or whether it is from absorption in consequence of that pressure, I cannot pretend to say: probably both

* [I have already observed, when speaking of the mode of union by adhesion in soft parts, that this is always accomplished by the effusion of coagulable lymph, which afterwards becomes vascular, and not by the organization of coagulated blood. The only difference in regard to bone consists in the time required for the ultimate organization of the new-formed structure. It is probable that there is no difference in the quality of the lymph (as it is first poured out,) from any of the structures of the living animal body, because the organic elements which enter into the composition of these structures are essentially the same, whether of bone or any other parts, viz. cellular membrane, nerves, blood-vessels, and absorbents. W'hen a bone is fractured, the periosteum and surrounding cellular membrane concur with the broken surfaces and lining membrane of the bone to pour out a mass of lymph {callus), which gradually undergoes successive transformations of structure, until the new-formed part closely assimilates in all respects to the old structure. For the first week or ten days it is observed to consist of a soft vascular granular-looking mass, which gradually assumes, toward the twentieth day, a white and cartilaginous aspect, and at the same time diminishes in bulk : from this period to the fortieth or fiftieth day the diminution of the callus still proceeds, and the process of ossification is now observed to have converted the greater part of it into true bone, although towards the centre of the mass a portion may still remain, which is not fully converted into bone before the expiration of the fourth or sixth month. If at the end of this period the bone be examined, it will be found to be thick and irregular at the point of fracture ; the medullary cavity will be found to be obliterated, and the new bone to possess the hardness of ivory. Ulterior changes, therefore, still go on for two or three years, which at last end in the complete restoration of the external form of the bone, as well as of the internal medullary cavity and reticulated structure. Dupuytren has called the external callus, which embraces the broken extremities of the bone like a bulky ferrule until the union is consolidated, the cal provisionel. There is not, however, as it appears to me, anything peculiar in this process to require the application of a new name, for the surrounding induration which attends the union of soft parts is precisely a similar phenomenon.] OF THE DISEASES OF BONES AND JOINTS, ETC. may act. The increased solidity of the new substance is either from the deposit of new matter, mixed with the first, or from absorption of the first, and deposit of new matter instead. I think the last the most likely. Ossification of the Callus.—The ossific substance is first deposited at the extremity of the bones themselves, and then extends to the callus; at the same time several points in the callus are forming ossific matter. Young people seem to have a greater disposition to form ossific matter than old, but there is a difference even in those of the same age. This new substance is similar to the original bone, and on this account probably is stronger than that from granulation ; however, it is not so durable as the original bones are. This process must necessarily be more tedious than in the soft parts, in consequence of the second process which is required; sometimes no union takes place for a length of time after the accident, and the variety of callus is great. Treatment in simple fractures.—Parts to be united by the first intention are first to be placed in their habitual position; but this cannot possibly be effected in all cases, nor is it always necessary in soft parts and when there is no external wound. In those parts which are for the support of the body, the fractured parts must if possible be brought into their original and natural position, before they are retained by bandage, &c.; but in some of these it is impossible, as in the ribs, clavicle, neck of the femur, &c, especially in fat lusty people. In such it is very difficult to say what the case is, or how the parts are situated. In the extremities there is more room for the exercise of art, but not in all equally. Simple fractures seldom affect the constitution except the soft parts are much lacerated; then there is generally constitutional affection in proportion to the degree of inflammation. Rest of the part is necessary : in most cases, therefore, splints and bandages are used; and when there is much inflammation expected, a folded compress, moistened with some cooling lotion, is applied until the inflammation subsides, and then rollers and splints are applied, which should be tightened as the limb subsides. Spasms often arise from the splinters pricking the soft parts ; I should think that a solution of opium would be the best application to remove this symptom. The position for the patient to lie in was formerly on the back ; but the side is now generally adopted. However, 1 think its whole advantage is that it has the appearance of novelty, and is not a real improvement; but time will establish the truth. I prefer the back position, with the knee bent, as the patient will support this for the greatest length of time, and it is always the position of debility. In this position the limb will be kept more steady, and will be less liable to be moved by moving the body.*

* [The use of fracture-boxes, consisting of two inclined planes, the angle of which is regulated by a rack-work, has led to the almost universal adoption of the position on the back in fractures of the lower extremities. These boxes are of various construction, but most of them combine the double advantage, first, of 272 HUNTER'S PRINCIPLES OF SURGERY. Period of Union, and manner in which this effect takes place.— The time in which the bone will be united will depend on circumstances. In the soft parts union will often take place in forty-eight hours: but it will require a much longer time in bones. In the first place they cannot be brought so closely into contact, therefore a larger quantity of new matter must become vascular; secondly, there is the second or ossific process to be effected; thirdly, there is laceration of the soft parts; fourthly, the state of the constitution and restorative powers may be weakened; fifthly, age. The situation too of the bone will cause a variation; the lower requiring a longer time than the upper extremities. In the middle-aged, and of a good constitution, union will take place in three weeks, so as not to admit of perceptible motion. If much longer in uniting, it will be very uncertain at what time this will take place: I have known it months, and yet unite at last. This slowness seems to be from imperfection in the two first bonds of union, the adhesive and the cartilaginous ; sometimes from a want of disposition to ossification.* These two, union by the first intention and that by adhesion, constitute the two first modes of union of bone; the third is where these two have failed, and here the union is effected by means of granulations from the broken ends of the bone and from the soft parts, which granulations become converted into bone (see note, p. 203). It is difficult to account for the failure of the first two: often it depends neither on the constitution nor the part; for the constitution has often been good, as is seen by it bringing on new inflammation on exposure. I have seen a simple fracture where the two first processes,

an easy position, resulting from the semi-relaxed posture of the principal muscles, and, secondly, of admitting of the application of fresh bandages and dressings without being required to disturb the fractured member. Mr. Earle and Mr. Amesbury have contrived beds on the same principle, which effectually combine these advantages, and must be considered as most important acquisitions in the treatment of compound fractures.] * [It may be observed that this want of disposition is particularly manifested during the periods of pregnancy and lactation, which would seem to divert the powers of the constitution from the reparation of the injury to the more important object of nourishing the offspring. The same effect will be produced by excessive depletion, or constant motion of the fractured extremities of the bones. By the former the naturally weak reproductive powers of bone are still further reduced, and by the latter the ossific process is arrested, and a new disposition created for the formation of a bursal structure, similar to what takes place in other parts of the body when friction is employed. It should be observed that constant motion of a fractured bone will inevitahly lead to the formation of a false joint; but this will be differently formed in different cases. If the process of union has been interrupted from the commencement, the broken extremities will be found rounded off and covered with hard enamelled surfaces, inclosed by an adventitious synovial bursa; but if the interruption has taken place durina the ossification of the callus, then the extremities of the bone will be united by a cellular or fibro-ligamentous structure. I am not aware that true cartilage is ever reproduced when removed from the surfaces of joints by ulceration, or ever found as a new formation on the extremities of bones forming a false joint.] OF THE DISEASES OF BONES AND JOINTS, ETC. 273 namely, the conversion of the blood into a vascular substance and the deposition of cartilage, had taken place, and the third had failed; and then, on allowing the parts a little motion, they got firmer, and at last perfectly strong. False Joints.—Sometimes simple fractures will not unite at all. This is a worse consequence than any of the foregoing, there being no soft union even, or, if there ever was, that being absorbed. Here the surrounding parts thicken and form a kind of capsular ligament, and the extremities of the bone rub against each other at each motion of the limb, by which stimulus the broken parts are absorbed, and the extremities become smooth, and in time are covered with something similar to cartilage, and at length the cavity between them becomes filled with a fluid very much resembling synovia. In this case it is necessary to lay open the new cavity and irritate the ends of the bones, and then, by keeping them in position, bony union will often take place. It has been recommended to saw off the ends of the bones ; but all that seems necessary is to irritate them sufficiently to excite a fresh inflammation.* Inflammation of Bones.—Bones are subject to the adhesive, suppurative, and ulcerative inflammation, as the soft parts are. The adhesive inflammation of bones is attended with this peculiar circumstance, namely, the formation of new bony matter in the inflamed parts, and therefore may be called ossific inflammation. Soft bones and the soft parts of hard bones are the most liable to inflammation and suppuration. Whether this arises from the structure of the bones or from some other cause, I cannot say. The suppurative and ulcerative inflammation is the same in the bones as in soft parts, as is also the granulation and cicatrization. When an injury is done to a bone sufficient to cause inflammation, or if inflammation arises spontaneously in a bone, then, some time ' after, there appears a swelling. This state is similar to the adhesive inflammation in soft parts. But pain appears to be the first symptom of inflammation in bones, and to precede the swelling a considerable time, whilst in soft parts they appear together. From this slowness in swelling it would appear to be a different operation, and it is * [It has not been found that any plan uniformly succeeds. Among the least severe methods adopted in these cases may be mentioned blisters over the seat of fracture, or lateral or longitudinal pressure (according to the circumstances of the case) of the broken ends of the bone, so as to excite inflammation. Thus, Sir Everard Home procured a fractured femur to unite by encircling the limb with a stiff leathern belt, and making the patient walk. A seton passed between the ends of the bones has succeeded in a few cases ; but the excision of the fractured extremities is much more effectual, although it is attended with the great inconvenience of shortening the limb. Mr. Hunter's is certainly a less severe method, and may be applicable to those cases, such as fractures of the tibia, where the bursal sac can easily be exposed ; although I should mention that it has lately failed in two cases in St. George's Hospital. I believe, however, that time and a well-adjusted apparatus will succeed in the great majority of cases, without having recourse to any other method.] 274 HUNTER'S PRINCIPLES OF SURGERY. difficult to understand how a bone can swell from extravasated lymph or calcareous matter, yet it is impossible to conceive that it is from any other causes. A swelled bone is true bone, and nearly as hard as any other bone ;* it is easily distinguished from the sound bone and from swelling of the surrounding parts. A cylindrical bone seems most liable and ready to swell at its extremity or softest part, which is the last formed part; and this is agreeable to what I have before said, that the latest formed parts are weakest and least able to resist disease. But in the bones of the skull the swelling is generally in the centre. Pain in inflammation of bones is more violent than in other parts. Whether this arises from the nerves being more compressed, or from the nature of the nerves themselves, is not easy to determine. This is rather a heavy depressing pain than an acute one, and is similar to that of rheumatism, generally more violent at night when warm in bed. This symptom is common to all inflammations of the bones and periosteum, though it has been supposed to be peculiar to venereal affections. In this stage the constitution is not much affected, except from the long-continued pain, which may be so continued and violent that the patient may in the end become considerably affected by it. We cannot divide the bones, like the soft parts, into vital and nonvital ; therefore we have not two species of symptoms. We have oftener, however, hectic from inflammation of the bones than from that of the soft parts. The parts surrounding the bone generally, if not always, sympathize with the ossific inflammation ; first producing simply adhesive inflammation of the periosteum, then of the muscles and cellular membrane. When considerable, this adds much to the swelling: the periosteum becomes fixed to the bone itself, so that this seems more swelled than in reality it is. The soft parts contiguous to the bone, besides sympathizing with the inflammation, receive the ossific disposition. The cells which contain the marrow are subject to be affected, so that the cavity is filled up, and the bone increased in size. The ossific disposition takes place in the surrounding parts much oftener than either the swelling of the bone or the ossific disposition of the cavity; therefore it seems an easier operation to nature. This ossific disposition in the soft parts assists in the union of fractures and in the formation of anchylosis. Here are bones [exhibiting them] where the ossific or adhesive inflammation had taken place in the substance of the bone, producing thickening of that substance; others where inflammation has taken place on the surface of the bone; and here, similar to the exudation of coagulable lymph on the soft parts, a coat of adventitious

* [There is great difference in this respect in different cases. Bones, in general, become spongy and light from inflammation ; but there are other cases in which they acquire a hardness and denseness of structure little inferior to that of ivory.] OF THE DISEASES OF BONES AND JOINTS, ETC. 275 bony matter is laid on the surface of the bones by ossific inflammation. This in some, you may perceive, is laid on so close and so thin as to appear like ossification of the periosteum ; in others it is loose and capable of being shelled off. In this bone of a lion it is laid on in places nearly half an inch thick, adhering closely to the bone; and in this it appears, from the little connexion it had with the bone, that the bony matter had grown from the surrounding soft parts. From this preparation of one of the bones of the lion, which had been injected and steeped in acid, it appears that this newly-added bone was vascular, and had only lost its earth by this steeping, its form still remaining; it therefore must be as much an animal substance as the original bone. This appearance on the surface of bones, some years ago, before I gave these lectures, would have been supposed to have arisen from caries. If a bone is bent, broken, or hurt, &c, the consequent inflammation produces an addition of adventitious matter, which will strengthen the part even beyond what it originally was. In disease of the bone, when the ossific disposition does not exist, we may observe that the periosteum is very slightly attached to the bone, being as easily raised from it as the cuticle may from the skin. Treatment.—The swelling of a bone, if of no specific nature, requires little chirurgical treatment, but will most probably require internal and external medicines before it can be reduced to its original size. If a bone be only in a state of adhesive inflammation, every method is to be used that is used in inflammation of other parts, as bleeding, rest, &c.; and if in the lower extremities, a horizontal position will add greatly to the cure. Fomentations will give ease, especially when near the skin. However, this treatment is sometimes ineffectual, and suppuration comes on. Suppuration, however, is not always the consequence; for in some cases the bone becomes indolent, and remains swelled for years. I believe bones are more likely to take on the indolent habit than other parts. The adventitious bone may always be considered as in a weak state, not being an originally-formed part, and as it is often in parts where it becomes an incumbrance, must be considered as a disease ; and if it could be removed it would be of service ; but in most cases this could not be done without producing worse effects. When bones take on this indolent habit, it will be necessary to rouse the diseased part to action. For this purpose mercury may be used internally, and pursued for a considerable time in a middle dose between what would be used in a venereal affection and what would be given as an alterative. Mezereon has been much recommended in indolent swellings. The decoction recommended by Dr. Russell is to be made as follows. Fresh mezereon root one ounce, pure water a gallon and a half. Boil it in a copper vessel tinned, over a moderate fire down 276 HUNTER'S PRINCIPLES OF SURGERY.

to a gallon. Towards the end of the boiling, add an ounce of liquorice-root, sliced. Half a pint is to be taken three times a day, which is more than most can drink. This does not increase any of the secretions, except being a laxative in a very few cases. It has been tried with double the quantity of mezereon, but was then too pungent for the stomach. Patients using this decoction are not confined to any regimen. The medicine has been strongly recommended in the Medical Observations by Dr. Russell. The cases he has described I should not call venereal, though they were treated as such, but scrofulous; therefore we may find mezereon a good remedy in scrofula. It cannot be considered as a specific in syphilis, as it is only useful when the bones are affected. Of the Suppurative Inflammation in Bones.—When the ossific inflammation is not cured, suppuration takes place. There is no visible difference between suppuration in bones and in the soft parts; for as bones are composed of animal matter with calcareous earth, there is no reason why they should not go through the same process. Suppuration does not indeed take place so readily in bones, the inflammation often not reaching so far. Whether this proceeds from an indolent disposition stamped on them from the first, or from their structure, I do not know; but whenever suppuration takes place in them it is a serious piece of business. The periosteum and surrounding parts are more ready to take on suppuration than the bone itself, yet it may originate in the substance of the bone. The consequence of suppuration is ulceration, which may also originate from pressure, or blood lying on the bone. There is, I believe, no difference between the ulceration of soft parts and of bone, the adhesive going on with the suppurative in the soft parts; so in the bone we have the ossific going on with the suppurative. To repair the loss that has been made, Nature sets herself to work to repair the loss with granulations. The intention of these is, to fill up abscesses; to repair compound fractures ; to restore the part lost by trepanning, &c. Nature sets about to repair these injuries of bones by the same original principles by which bone was first formed: thus, if a cylindrical bone is to be restored which was originally formed on cartilage, the first step to its reproduction will be the formation of cartilage ; if a bone in the skull, it will be of membrane. But we sometimes have too great a disposition to ossification in the granulations, so as to make the new part bulky and inconvenient. A difference is observable in the newly-formed substance which arises from ossific inflammation and that which is formed from granulations in consequence of ulceration. The former has a smooth fibrous appearance, very different from the latter, the surface of which is granulated, as if the bone had grown from the centre to the circumference, the grain being of a sandy texture. Compound Fractures.—These differ from simple fractures in the first and second modes of union being lost; and therefore the third, by granulation, takes place. The granulations between the ends of OF THE DISEASES OF BONES AND JOINTS, ETC. 277 the bone and on the lacerated surfaces take on an ossific disposition, and the suppuration is always more or less surrounded by the adhesive inflammation, so that it extends pretty far, and consequently the callus'is large. Hence these fractures are so tedious and dangerous, especially when in the lower extremity, which is their usual situation. There are no bounds to the mischief done by a compound fracture: the loss of the uniting substance by the wound, and the loss of the living principle to what remains by the exposure, are causes of the failure of the first process; and, besides, the ends of the bones are sometimes so locked together as to require to be sawed off, or so denuded of their investing membrane as to lose their living principle and to exfoliate, as the dead part must be thrown off before the wound can heal. This sometimes takes six or eight months, and is so extensive as to be very dangerous. The inflammation, too, which follows the accident is commonly very considerable, and may proceed to mortification. Treatment.—The only peculiarity in compound fracture by which it differs from other lacerated wounds is the breach of continuity of the bone, which admits of motion in the part where none was intended. This singularity it is which requires a peculiarity in the treatment, as this motion and the operations of nature are in contradiction to each other. A variety of inventions have been employed to prevent this motion; but the dressing of the wound every day counteracts the effect of every invention that has been thought of, and it is perhaps impossible to dress the sore without motion (see note, p. 271). At first the part is generally put into a poultice, but changing this must give considerable movement. Instead of a poultice, I would lay the leg or arm in cloths, doubled several times, and wetted with goulard, and lap them over so as to come into contact. These should be wetted occasionally, and continued until the inflammation is over and the suppuration takes place. When the wound is on the back of the leg we shall be obliged to raise the leg every day to apply the cloths. A bit of oil-cloth should be put under the leg, and wiped clean every day. The time of union of a compound fracture is necessarily much longer than that of a simple fracture, from the processes they have to go through, and is very uncertain; but the union of the bones is generally effected long before the external wound is healed up, for whatever retards the cure of the bone retards also the cure of the sore. When granulations have been formed and bony union is late in taking place, and the wound is healed up or nearly so, it should be treated like a simple fracture in the same circumstances, and gentle pressure is of use, as walking, with a machine to take off the weight of the body: here necessity acts as a stimulus for bony union to form. Compound fractures do not always take on the bony union: but there is never a want of soft union, as there is at times in simple fractures ; and therefore new joints are never formed, as they are 24 278 HUNTER'S PRINCIPLES OF SURGERY. sometimes when simple fractures do not unite by the first or second modes of union. Compound Fractures communicating with Joints.—Joints do not so readily go through the suppurative and granulating inflammation when wounded as other parts; and it would be improper for them to do so, as it would produce anchylosis. If, in a compound fracture, the fracture extends to a joint, the question arises, What shall we do ? The injury may be viewed in one of three lights : first, as a compouud fracture; secondly, as a laceration of a joint: thirdly, as a compound of both. If it is such a fracture as seems impossible to recover, it is not necessary to consider the joint at all, but amputation must be performed. If the laceration into the joint be such that, although the fracture may not be considerable, inflammation and suppuration of the whole joint must come on, then it is probable that amputation must also be its fate. But if the fracture appears to be such as may unite, and the laceration in the joint be such as can unite by the first intention; if the fracture be such a one as we think would do well when restored to its situation, if not complicated with a wound in the joint, it becomes dubious what ought to be done. If the wound in the joint will admit of being kept from exposure, then we may consider the case as one of compound fracture only. This sort of injury most often happens at the ankle joint, this tibia being very liable to fracture at its lower extremity. All wounds of the joints should be healed by the first intention, if possible.* Of Fracture of the Patella, Olecranon, and outer Ankle.—The peculiarity attending these fractures is, that they make the lateral part of a joint so exposed that the fracture communicates with the cavity of the joint which gives an exit to the immediate bond of union. The treatment of the patella and the olecranon will be very similar, because they not only make the lateral parts of joints, but they have inserted into them the tendons of considerable muscles. Hence the fractured ends are separated from each other, instead of riding over one another as in common fracture, and a different treatment is consequently necessary. As the fractured patella is commonly produced by a contraction of its muscles, especially when opposed by a resistance of other

* [The question of amputation in cases of compound fractures, is one which depends on many circumstances: as, for example, the implication of the great joints; the degree in which the soft parts are bruised and injured and the bone comminuted ; the injury of the principal vessels or nerves of the fractured limb, as well as the age, previous habits, and present conveniences of the patient. Without, however, going into the subject further, it maybe sufficient to mention that surgeons are now more in the habit of trusting to the efforts of Nature than used formerly to be the case; so that cases which would certainly have been condemned by Pott and Hunter are frequently saved in the present day. Where youth and a sound consiitution exist, the surgeon should be especially careful not hastily to condemn a fractured limb because the joint happens to be implicated, or on account of any other simple circumstance; but should reflect how extensive the resources of Nature are, and that an attempt to save the limb in the first instance will not necessarily preclude his having recourse to the remedy of amputation in a later period of the case.] OF THE DISEASES OF BONES AND JOINTS, ETC. muscles, the fracture is then transverse, and then the muscles are at liberty to contract to their full extent, and consequently the broken part of the bone above is drawn up the thigh with them, for the rectus muscle has more than a simple power of extending the leg, namely that of bending the thigh on the pelvis. Treatment.—When the ends of the fractured bones are pretty soon brought tolerably close together, I can conceive that union may take place as in simple fracture. Before the year 1750 it was the practice to endeavour to bring the broken ends of the bones as near together as possible, with little or no motion allowed; but after that a fashion arose (for we have fashions in surgery as in everything else, arising perhaps from a person happening to do well who had not been treated in the old way,) of letting the parts separate, and of not forbidding motion so strictly; but now caprice has I believe had its day, and we are taught by reason and experience that the parts should be, when cured, as nearly as possible in their natural situation. To effect this, the upper portion of the patella should be brought down as much as we can, and the common bandage be applied. It may be imagined that in the treatment it is not only necessary to extend the leg, but to lay the thigh at right angles with the body; but from a complete knowledge of all the circumstances, it will appear that this practice is not at all necessary; for as the rectus has a greater power of contraction than extending the leg, so it must also be granted that it has a greater power of relaxation; therefore it is not necessary to place the leg at right angles with the body. Fracture of the patella seems to be cured by Nature, in the manner of the simple fracture, by granulation, because the first and second bonds of union have escaped into the cavity of the joint and have been absorbed. But, perhaps, if the ends were brought together earlier, they might be united by the same means as the common simple fracture, especially as we sometimes see a luxuriance round their edges, which is probably owing to the ossific disposition having taken place in the coagulum. But if the first and second modes fail, I conceive the third, by granulation takes place: the ends of the bone and ligaments exuding coagulating lymph, which coagulates immediately, and, taking vessels as in other granulations, becomes not bone, but a kind of tendinous or ligamentous substance; which seems a wise provision of Nature, because if they were united by bone, this might be of such a length as would prevent the motion of the joint, except with the leg at right angles with the femur. When union is formed it would be proper to give some passive motion; but voluntary motion is always better, because the will is always sensible how far the powers of a part extend, and will attempt no more; but if force is used to extend a part, all the muscles of which have not their due power, it may be thrown into such a situation as to give an improper action to a weak muscle: the will alone is proper to perform those actions she has determined on herself. 280 HUNTER'S PRINCIPLES OF SURGERY. The method of cure by ligament only is very tedious; but there are other things to be done after this union has taken place. First, the accommodation of the muscles to their new situation, where less length is necessary, from the patella having become longer; secondly, the new contraction in this new situation; thirdly, acquiring sufficient strength in it. We have reason to believe that the greatest contraction in a muscle is somewhat greater than the joint will allow of; for we find them firm when the limb is stretched as if the power was greater; and when the part is deprived of this firm band we find the muscles draw the bone up higher than they should. Thus the upper part of the patella is always drawn up when the bone is broken. While the union is taking place, the muscles are accommodating themselves to the great length of the bones. After this it will be necessary to bend the limb and keep it so, in order that the muscles may be thus enabled to admit of an elongation equal to the flexure of the limb, by which means the patient will be enabled easily to bend the limb. Extension will not be so easy ; but still by perseverance it may be acquired, as the following case will show. I called with a friend to pass a day or two with a family in the country. The lady of the house had had her knee fractured, and had been treated according to the maxims the surgeon had learned while attending the London hospitals, which at that time were to leave the whole unconfined, and take no measures to bring the portions of bone together. She recovered from the accident, but was totally unable to use the limb, and had to be wheeled about in a chair. Her leg was made to swing backwards and forwards as she sat on a high table or chair, but still she had no power of contracting the rectus muscle, and as soon as the force that gave the motion ceased, the motion ceased with it. It was not until several years after the accident that I saw her; and, having spent a whole night in considering the probable cause of her loss of power, it appeared to me that the space between the two attachments of the rectus being much shortened, while the muscle continued of the same length, the utmost degree of its contraction would scarcely be able to straighten itself, much less move the patella and leg also. I advised her to sit as before, but instead of having her leg moved, to move it herself. This she could not in the least effect at first. I considered, however, that the power of contraction which the muscles possess beyond that necessary for the mere purpose of extending and flexing the limb, as mentioned above, is probably obtained by the mind's influence on the muscle; and that, in this case, if the influence of the mind was frequently exerted on the muscle, it would gain this power of contraction, in which it would probably be aided by the interstitial absorption taking place, and actually shortening the muscle and suiting its length to the office it was to perform. I therefore advised her ladyship to repeat her exercise, as often as she could, every day for a month, assuring her that if at the end of the month she had obtained the least power of motion, I had not a doubt that she would OF THE DISEASES OF BONES AND JOINTS, ETC. 281

again be enabled to walk by a regular exercise of the muscle. The event proved as fortunate as I could wish: the lady, at the end of three or four months, being able to walk, although she had not walked for years. Fracture of the Olecranon.—The olecranon may be considered as a fixed patella, the inserting-point of a considerable muscle, and when broken is drawn up as the patella. The immediate treatment is the same; but the consequences are often different, as it should always be united by bony union. The arm should be extended, and kept so ; and the upper portion brought down, if up, and retained by a bandage, which will be somewhat similar to those used after bleeding. When soft union has taken place, and bony is beginning, passive motion of the joint should be made. As the union gets stronger, the motion should be increased, but should not be very great till bony union is completed, as before this it will bend the olecranon over the lower end of the os humeri, and occasion it to make a smaller curve than it should do, even an angle; by which the full extension will be prevented. This, by proper attention, may be avoided. Fracture of the Ankle Bones.—It is possible for these to unite in general, like simple fractures, as the displacement can hardly be very considerable, unless great injury has been done, here being no muscle fixed to them, the contraction of which would draw up the parts ; so that the extravasated blood and juices may be sufficient to unite them by the first intention. Suppuration in Bones.—I shall first consider that on the surface of bones, or on the periosteum ; secondly, in the substance ; thirdly, in the medullary parts ; fourthly, may be reckoned that in the joints, which is similar to that of a bone; but, as it is attended with consequences peculiar to the nature of the part, I shall treat of them after. When inflammation attacks the surface of a bone, the first effects are adhesive ; and when suppuration takes place, the periosteum is separated as far as the suppuration extends, making underneath a cavity for the matter. As the adhesive state takes place some way round the abscess, there is in many cases a circle of adventitious bone formed in the periosteum round the abscess. This will be more or less, according to the rapidity of the suppuration: if it takes place soon, there will not be time for the ossific inflammation; if slowly, a ridge will be formed, as is often the case in the cranium giving the appearance of bone being wanting under the muscles. As soon as ever it is known that suppuration has taken place, it should be freely opened, to prevent as much as possible the separation of periosteum ;* granulations will form, and in proportion to

+ [The propriety of this direction cannot be questioned as regards those cases where collections of matter between the periosteum and bone give considerable pain, or where, suppuration not yet having taken place, the suffering from the periosteal inflammation cannot be subdued by the ordinary antiphlogistic and mercurial treatment. It should be recollected, however, that considerable col- 24* 282 HUNTER'S PRINCIPLES OF SURGERY. them will the ossific disposition follow, which ossific disposition is often not confined to the granulations, but exists in the surrounding cellular membrane, &c.; so that, around the bone, ossific matter is deposited which increases it very much in thickness : this is seldom the case when the granulations are healthy, but almost always when unhealthy. The oftener bones have undergone inflammation and ulceration the thicker they become, and also much more subject to it, as we evidently see in working-people's legs, &c. Often, from the separation of the periosteum, part of the bone dies, and must exfoliate. The second Species.—This is of greater consequence, as more of the bone becomes diseased. When inflammation attacks the substance of the bone, it is seldom that the whole diameter of the bone swells, generally only on one side, w-here the suppuration is. This must at first be much confined, from the solid parts around, and ulcerative inflammation is obliged to take place early; and accordingly, as in common abscesses, the ulceration goes on towards the soft parts, and until it arrives there it is impossible to tell whether there is abscess in the bone or not.* It will burst, as usual in abscesses; but this probably does not so quickly take place here as in soft parts. When near the external surface, and so near the periosteum as to give it the stimulus of adhesion, then the adventitious substance is formed on the external part of the bone, while its substance is gradually lessening internally by absorption; but the addition externally is not in proportion to the internal loss, and therefore it bursts externally. [Preparations of this were shown where suppuration and ulceration had taken place in cylindrical bones, as in the tibia, Sj-c.'] This used to be called spina ventosa. The third Species.—Inflammation in the medullary part is still more serious in its consequence than the last. The body of the bone thickens from the adhesive disposition, and also the ossific disposition takes place in some degree in the periosteum all round, so that the external parts are much increased in bulk; this only takes place in the bones of the extremities, where strength is necessary, and never in the scalp, &c. The ossific disposition in the medullary parts takes place at all points of the abscess; and by this the other part of the marrow is saved. When suppuration takes place, there being no vent obliges the ulcerative inflammation to take place: on all sides and on the outside additional matter is deposited. Nature intending to keep up the strength which it is losing internally; the

lections of pus, arising from a venereal cause, are frequently dispersed by an appropriate treatment directed to the cure of the original disease; especially when such collections are situated on the frontal bone.] * [Notwithstanding the great obscurity which involves the early existence of these cases, yet it is not always impossible to discover their true nature. In the clinical lectures delivered by Sir Benjamin Brodie, that gentleman has related several cases in whioh he has detected and given exit to circumscribed abscesses in the heads of bones entering into the composition of the larnre joints. Such oases are marked by a fixed deep-seated pain in some determinate spot, unattended by any considerable swelling of the parts, or disease of the neighbouring joints.] OF THE DISEASES OF BONES AND JOINTS, ETC. 283

newly-formed bone is itself disposed to the ossific inflammation, by which it in many parts becomes much thickened, so that the remaining shell is often entirely new. Where the two opposite processes do not bear a proportion to each, the bone becomes often so very thick as to resemble a compound fracture. In the two last mentioned we have often exfoliations, as well as in the first; they are less favourable, from their situation being different, and are called internal exfoliations. The head of the tibia is more subject to abscess than any bone in the body. The medullary arteries and membrane, which furnish nourishment for the internal laminae of the bones and marrow, is the seat of the inflammation producing it. \_A preparation was shown where it was very large, but only a mere shell remaining.] Treatment.—When the adhesive or ossific inflammation does not stop, but goes on to suppuration, it must be treated as inflammation in soft parts. When the suppuration is superficial, so that the bone only makes one of the sides of the abscess, the matter will come immediately to the surface. All the soft parts are to be laid freely open, or entirely removed. This is necessary in all wounds, where healing does not take place from the bottom, to expose them and bring on inflammation; and when there is exfoliation, the opening is more necessary, as it cannot heal until this is removed, and it will sooner be removed and healed by exposure. It will often be necessary to remove a part; but when the skin and bone are very near, then it must be only a simple opening, without removing the skin, as in such cases the skin is fixed very much to the bone, and should not be lost; and again, here the granulations have less power to contract than in deeper and more fleshy parts, and there is less danger of sinuses or fistulous openings; but when deep-seated, simple and free openings are insufficient, and some parts must be removed, otherwise the external opening will close, and fistulous openings will remain till the bone has recovered* Bones are very apt to fall into an indolent inactive state, which should be discovered, and stimulating dressings applied. Oily dressings have been objected to; but oil has neither a power of promoting nor retarding granulations, though the former has been imagined to be the case. By this means they are often cured, but are afterwards very liable to new inflammation; and this is generally attended with ulceration, which begins in the skin. This is owing to weakness in the part, and is most frequent in the lower extremities. In some cases it will be necessary to apply the actual or potential cautery to the bone. The treatment of these cases is various, and the cure is generally very difficult. They are seldom understood: at first they may appear as a common abscess, and are often opened and dressed as such, which, proving generally ineffectual, leads the surgeon to a more particular examination, and he easily discovers a diseased bone, if the opening has been free. As the bone cannot be dilated by a cutting instrument, it must be killed either by the potential or 284 HUNTER'S PRINCIPLES OF SURGERY. actual cautery, or sometimes the trepan will be useful. After exfoliation is finished, the same dressing as in caries is required ; but in many cases it will be necessary to do something more. The cavity of the abscess in some requires to be exposed, by removing surrounding parts, as is sometimes done in abscesses of the soft parts before they will heal. Of the Matter in Diseased Bone.—The matter discharged from a sore where there is diseased bone is seldom good matter, especially if it become fistulous. The diseased bone that is bare is often producing mechanical effects, such as rubbing the soft granulations, so that there is a small quantity of blood mixed with the matter, which gives it a bad colour. Such matter generally blackens or in part corrodes silver probes. This probably arises from the hepatic air (sulphuretted hydrogen gas) which Mr. Kirwan has discovered to be produced by the putrefaction of animal matter. Of the Shortening of Muscles of Diseased Joints.—Joints when diseased naturally get into a middle state between flexion and extension; and, as the joints are passive, this must be performed by the muscles, and either by their voluntary or involuntary action. This stiffness of the joint depends on the involuntary contraction of the muscles, and is in consequence of the muscles sympathizing with the joint But this involuntary contraction is not like tetanus; the muscles in this state feel like strong cords, and, if straightening the joint be attempted it seems to the patient as if these cords were breaking. As the joint loses its power of motion by the disease, in that proportion the muscles are altered; they adapting themselves to the quantity of motion the joint will admit. In the artificial extension of a joint which has been contracted, the muscles which are contracted should never be called into action, because the parts which ought to lengthen will thus be shortened. To illustrate this, let us suppose the gastrocnemius and soleus muscles to be contracted, and to draw up the heel, so that the patient rests on his toes, his foot being in a line with his leg: in walking he will involuntarily use these muscles to give firmness to his leg. In this case we should give support to the heel in a degree. By this means the patient, convinced of his ability to bring his heel as low as the support requires, will cease voluntarily to contract the gastrocnemius and soleus muscles, and they by degrees will acquire the property of relaxing themselves ; which, if the heel was entirely supported at first, they would have no occasion for, and while altogether unsupported they never could.

Of Sprains.—In sprains the ligaments are probably often torn ; for in most sprains there is a considerable extravasation in the surrounding cellular membrane. Considerable pain is felt, at the time of the accident, of the heavy dull kind, which often produces sickness, and the blood leaves the skin of the body generally. Considerable swelling takes place, and this is almost instantaneous. The swelling arises from two causes; the surrounding cellular membrane being loaded, and the increased OF THE DISEASES OF BONES AND JOINTS, ETC. secretion of synovia into the joint. This will be more visible in the joints where the capsular ligament is loose, as in the joint of the knee above the patella. These symptoms are succeeded by inflammation, which produces great pain and sensibility on motion. These parts are very insensible in a sound state, but they easily move from a state of insensibility to one of sensibility. Nature does not seem to have bestowed so much pains on these parts as on others, for they have very weak powers of restoration, which produces tediousness of cure. Treatment.—In the first place, rest should be employed, with topical bleeding. Pumping on, or long immersion in cold water, and friction with vinegar, lees of wine, spirits of wine, &c. on the part have been recommended. Whether these last reinedies serve any useful purpose or not I am undetermined: but we know that sprains are at least seldom perfectly cured. I have known the effects of a strain continue through life (above fifty years), always swelling and becoming painful on the least violence. Where there is a perfect cure obtained, I suspect the ligaments only have been injured, and not the cartilage, which is extremely slow to restoration. Though the mechanical strength is recovered, yet a weakness is often found to remain, which may sometimes be removed by some application which has not been before applied, as a pitchplaster, opodeldoc, &c, which gets the credit and the name of a specific: but these often fail. The same applications are often recommended in the second stage as in the first, but to use it in the same way must be improper. In the second stage cold water should be applied no longer than to excite heat. Sprains often remain very painful after the original symptoms have been removed; this pain is often removed by giving the part motion, as if some part was moved into its place by that motion; but it is most probably by the motion's giving the parts an opportunity of adapting themselves to each other's action. On Dislocation.—This term generally is applied to bones, and probably might also be applied to cartilages, when any two bones forming a joint are displaced. Probably the articulating substance or ligament is torn; but this circumstance is not yet well ascertained. In many joints a lateral motion must be applied to produce it, the muscles being at right angles with the bone that they move, &c. When the head of the bone has moved beyond a certain point, then the antagonist muscle is unable to bring it back, and then it requires some passive motion to bring the bone so far back that the antagonist muscle can replace it. A lady had the tibia brought too much below the os femoris, by too great flexion: the surgeon attempted to replace it, by bringing the foot forward, and so to replace it by the extensor muscles: but I thought the tibia was got beyond the centre of motion; therefore I conceived that the above means would make it worse : he then, by my direction, raised the head of the tibia a little upwards, by placing the hand 286 HUNTER'S PRINCIPLES OF SURGERY. in the ham, and the reduction of it was then finished by the extensor muscles. General observations on the Reduction of Dislocations.—As joints are composed of two parts, one more moveable and the other more fixed, the more fixed might be called the reactor, and the moveable part the actor. When a violence has been applied to the actor there is a deformity occasioned, as if this was out of its place, yet both are equally so. In dislocations the powers are generally applied to the actor, and though in most cases the reactor does its office spontaneously yet it often requires assistance. In most joints of the body the reactor can be made more fixed, as, e. g., the body in dislocated hip, but in the shoulder there wants a counter resistance, or reactor, the scapula being so very moveable, and hardly to be fixed by art: hence extension is obliged to be more on the muscles, as the latissimus dorsi, pectoralis, &c, than on the ligament where it should be; therefore, to reduce it, it is necessary to make the scapula a fixed point, to do which often requires much labour and some art. When you stretch the shoulder as far as it can, the scapula is brought forwards as much as possible, but the latissimus dorsi and pectoralis major prevent the os humeri from being extended on the scapula beyond a certain point, which is much against you in the reduction. In reducing a dislocation the bone should be returned exactly in a retrograde motion, overcoming that effect first which was produced last, and then a lateral motion is to be made in a contrary direction to that motion which occasioned the dislocation; in doing this the most immoveable part is to be the fixed point if possible, and the moveable is that which is to be extended. This is to be done as soon as possible after the dislocation, as afterwards the parts will become adapted to their new situations, and render the reduction more difficult, and sometimes impracticable. New Joints produced in consequence of Dislocations.—We have sometimes new joints produced in consequence of dislocations when the bones are not reduced, which brings the parts into somewhat of the condition of simple fracture ; and there is the same disposition between the two surfaces in contact as in simple fractures which do not unite by the soft continuity of parts. But this can only be when the dislocated bone comes in contact with another bone, as the thigh-bone with the ilium. When the two bones rub and press on one another absorption of the external surface takes place, the adhesive ossific inflammation goes on around the edges, a fluid is secreted in the cavity, and thus we have the new joint. These joints of necessity oftenest take place in the thigh-bone than elsewhere, but sometimes between the os humeri and the scapula. The effects of Accidents and Inflammation of Joints.-—They being circumscribed cavities, are subject to the same diseases as other circumscribed cavities, as inflammation, &c, but their peculiar structure sometimes renders their consequences different. Nature is very little disposed to take on the adhesive inflammation, because OF THE DISEASES OF BONES AND JOINTS, ETC. the necessary consequence would be loss of motion in a part originally intended for motion. This makes inflammation in joints so much worse than in any other circumscribed cavities, for, as before observed, if adhesive inflammation does not come on, the inflammation and consequent suppuration must spread through the whole cavity. The joints are mechanically strong; yet this is not that sort of power which resists disease; but they have sometimes a greater disposition than other parts to disease ; and sometimes they become diseased from the violence of accidents. They are slower of cure from their composition, than other circumscribed cavities are; besides, they are also subject to specific diseases, from the materials which they are composed of, and more backward in their cure. Inflammation in joints is generally of more serious consequence than in other parts; even when resolved it is disagreeable; yet this is always to be wished for. Inflammation from accidents often does well without any adhesion, but not when it arises from other causes. In all inflammations of joints there is a swelling, from extravasation, into the cellular membrane and cavities, as in the knee above the patella, where there is a sacculus mucosus. In inflammation from accidents the treatment must be similar to that in other parts, but here suppuration is particularly to be prevented if possible. Rest, topical bleeding by leeches and cupping, fomentations, blisters, purgatives, &c, are here to be particularly employed ; but as joints are very apt to become scrofulous, the patient should go to the sea when the swelling becomes chronic and appears to be at all stationary. Another cause of accidents here, besides strains, is extravasation of blood. Of loose Substances found in Joints.—These are ligamentous, cartilaginous or bony. Though there are often extravasations into joints, yet they seldom produce adhesions, although sometimes there are appearances as if blood extravasated into a cavity of a joint had become vascular. To explain this we must have recourse to the living principle of the blood. This, I suppose, when it is extravasated into a cavity, adheres to the cavity, and is not absorbed nor loses its living principle, but becomes vascular, and afterwards membranous, cartilaginous, or bony, according to circumstances. Its attachment being rendered small by motion, it becomes easily broken off, The treatment of these cases we have before mentioned when the joint was sound ; sometimes there is more than one of these substances. I know a gentleman who has four; therefore if an operation was to be performed we must take care to manage it so as to extract all of them at once. They may often occasion lameness in other joints where they are not discoverable ; but they are most liable to form in the kneejoint, from its greater size, and other joints might not so readily show their existence. These loose bodies can only be removed by making an opening into the joint, and this should only be done when they are evident. On the inside of the upper end of the 288 HUNTER'S PRINCIPLES OF SURGERY. patella is the best place; the loose pieces should be squeezed to that part, and then carefully surrounded by three or four fingers of an assistant: the incision "should be longitudinal and in length proportionate to the size of the loose bodies. The wound should be closed immediately by adhesive plaster and the uniting circular bandage, and the patient kept in bed for some days to procure the first mode of union if possible, the leg being kept quiet and extended, and the occurrence of inflammation carefully watched. Anchylosis.—This is an union of bone with bone which ought not to be united, and is of two kinds,—one by soft parts, the other by bone. In inflammations of joints we often have adhesions by a soft medium. Very considerable inflammation is necessary to produce anchylosis in joints, and much time is necessary for their perfection, as we see in white swellings. The adhesions are sometimes partial, sometimes universal. The soft is from two modes, viz. adhesion and granulation. The soft only can take place when there is naturally no intermediate substance, and the joint is surrounded by capsular ligament. Bony Anchylosis.—I shall divide bony anchylosis into five kinds, four of which are in the surrounding parts, by ossific inflammation, the other by an entirely new substance, betwixt the extremities of a bone. Distinct and separate bones are naturally united, either mediately or immediately; that between rib and rib, between tibia and fibula, and radius and ulna, is lateral attachment. The second is when there is an appendage for the union of two bones, as in joints in general; this is of two kinds, viz. 1st, when the whole surface is united by soft parts, or ligament, as vertebrae to vertebras; the other, when only round the extremities by caspular ligament. These will have different effects. When there is no continuity of soft substance, but only the bones, then the inflammation is obliged to shift the ligaments for bone. Of the first, from lateral attachment where there is no joint.—This generally takes place only when the bones are so near as to partake of the ossific inflammation between them, as in the tibia and fibula. This anchylosis is of little inconvenience, except between the ulna and radius, when their motions will be rendered imperfect. [A preparation was exhibited which showed the union of a tibia and fibula, by the ossification of the interosseous ligament; another, the union between two ribs; and another, the union between two of ihe metatarsal bones.] The second, or in surrounding parts.—This often takes place in bones united by their whole surface, as between vertebras and vertebrae, and I have seen it between sacrum and ilium; it often occurs in the human species, but much oftener in horses. The ossific inflammation would appear in such to arise from the bone, as it is found to be in different degrees. Sometimes the ossific inflammation attacks the periosteum around the connecting substance, leaving this as free from bone as ever. In a horse the vertebrae unite, not by ossification of the intermediate substance, OF THE DISEASES OF BONES AND JOINTS, ETC. but by the periosteum covering them becoming ossified. The same also occasionally happens in the human vertebrae, the intermediate substance not being at all ossified. Of the third, or between bone and bone.—Within joints, but with a continuity of substance, anchylosis often takes place in the vertebrae, by ossific inflammation having existed in the intermediate substance, These specimens [exhibiting them] show the intermediate substance ossified, while the external parts are little or not all affected. In the spine of a lion both are affected. The fourth, by capsular ligament.—This is much worse than the former, here the bones having a considerable motion, and this motion very necessary; but in some of these joints there is more inconvenience from anchylosis than in others; it is from the capsular ligaments taking on the ossific disposition, after strains and other injuries; however, this is much less frequent than the others and very long in coming about throughout and all around the ligament, though a partial anchylosis may take place which will render the joint stiff. [A preparation of the os ilium, anchylosed in part with the glenoid cavity, by ihe surrounding capsular ligament becoming in part bony, was shown. In the elbow another was shown, of this species of anchylosis.] The fifth, by the whole substance of the articulation.—This is of two kinds, and these kinds are the only ones which can admit of the soft anchylosis. It is somewhat similar to the union which takes place in soft parts; it arises from two causes, viz. 1st, from inflammation of the parts themselves; 2dly, from the inflammation of the surrounding parts, the parts themselves partaking of it. Sometimes the cartilages are ossified, and a new substance is formed on them, which I rather think arises from granulations without suppuration. Joints have lost their motion from inflammation in surrounding parts. A lady had an inflammation come on from the opening of a sacculus mucosus on her elbow, which inflammation was very violent, and extended to the joint, soon after which she lay in, and died of puerperal fever. On opening the joint, soft union was found to have taken place, which, if she had lived, would probably have become bony, and the joint would have been anchylosed, merely from adhesive inflammation. Of Suppuration in Joints producing Anchylosis.—This is of two kinds, viz. truly inflammatory and scrofulous; the former we shall now treat of principally. If the inflammation is carried on, an abscess is formed in the cavity, as in any other part; and the suppuration is more universal in the cavity than in other parts, being diffused through the whole. This continues to approach nearer and nearer the external surface, and either breaks or may be opened: so far as they are connected with bone they are similar to compound fractures; but the suppuration is slow, and takes place with difficulty, and then generally falls into the natural scrofulous disposition, which renders it tedious. The suppuration is then imperfect, appearing to partake of both the adhesive and 25 290 HUNTER'S PRINCIPLES OF SURGERY. suppurative. The ulcerative disposition is slow in bringing the matter to the skin, which arises from the indolence of the prior suppurative disposition and inflammation. The ulcerative inflammation sometimes goes on, so as entirely to alter the joint, that is, the receiving cavity becomes larger, and the received part less; this is often the case in the hip joint. These cases then become very tedious, and generally very uncertain in their cure. Before they are opened they are generally become so indolent that opening has very little effect; and often when scrofulous such a disagreeable inflammation comes on as to destroy the patient, and therefore amputation had better be performed at once if this disagreeable inflammation does not take place immediately after opening; yet a fistulous opening is generally the consequence. Soft Anchylosis from Granulations.—A joint so healed has no cavity left, the surfaces uniting. A joint coming to suppuration from not being resolved in the first mode, but forming granulations, is more tedious than in the soft parts. The granulations cannot contract here, as they do in the soft parts, and the powers of restoration in them are very weak. Bony anchylosis takes place when the granulations ossify, so that the two bones are united into one exactly similar to a compound fracture. [Preparations were shown; one, of the thigh united to the acetabulum; another, of the ulna to the os humeri; and another, of the metatarsal bones.] But when the suppuration is healthy the joints sometimes recover: in such cases the matter is sooner discharged, and the parts are more disposed to return into their original state. The modes of cure.—The first attempt should be to resolve the suppuration without opening. In some the cartilages have been destroyed (which may be known by the bones rubbing against each other,) and replaced. This I have seen in the knee. When a healthy process is going on, the joint should be attended to. Rest should be prescribed, both before and after it has taken place; when it is recovered pretty well, a little motion, and gently repeated, should be allowed; thus a cartilage will gradually form on the parts moved. The second mode of cure is the formation of granulations, which makes anchylosis complete by their union. Of Muscles losing their Action from injuries done to Joints, Tendons, and Ligaments.—It is remarkable that an injury done to tendons, ligaments, fasciae, &c, especially of the strain kind, impair the muscles more than when the muscles themselves are injured, so that these muscles appear to sympathize with those parts of little action, and become wasted and weakened in consequence. I think this arises from sympathy, or a consciousness of the parts being unable to answer to the action of the muscles, and it comes nearest to human reason of any thing in the body. If the affection be temporary, as in common inflammation, the muscles do not waste, being then conscious that the parts will recover. If one tendon is OF THE DISEASES OF BONES AND JOINTS, ETC. 291

materially weakened, the muscle will also; and then, if the motion of the joint depends on that muscle, lameness will be occasioned, and the other muscles will become also affected. If a joint recovers, the powers of the muscles begin to recover in proportion. This is the case after injuries of the joints, as fractures, or ruptured tendons ; and the first intelligence of recovery in a joint will be the enlargement of the muscles. This is the case in paralytic parts, from the cutting of a nerve ; the wasting is not occasioned by the deprivation of the nerve depriving it of nutriment, but from the muscles losing their power of exertion. If the hip is affected, the muscles of the leg or knee will waste, whilst those of the foot will not be altered, which would be the case was their wasting owing to want of nutriment from the nerves. If the elbow is affected, the muscles of the arm surrounding it will waste, whilst those of the hand will not be affected. When the muscles waste, in consequence of a disease in the joint, the surgeon will often say it is from want of action ; but if he will only observe the other leg, he will find the muscles nearly of their full size, though they have had no more motion than the mnscles of the diseased leg. The mind, likewise, loses its power over the muscles, for the will has never any power over muscles while the parts they move are unfit for motion, even although the muscles are not wasted. The effects which a disease of a part has on distant parts.—Many diseases of this class produce diseases of debility, as for example, involuntary contractions of muscles, oedema, inflammation, and sometimes mortification in parts beyond them ; thus, in a disease of the loins some of these effects follow in the lower extremities. Though they only arise while a disease is present, and is in its height, yet the disease may be cured, and the inability in the joint remain, as is the case in anchylosis. But here I may observe, concerning the contraction of muscles just mentioned, that it may take place together with these diseases, as in white swellings of the knee. But then it is very different from these diseases, the contraction proceeding from an endeavour of the muscles to adapt themselves to the state of the joint, whilst these are only like symptoms of beginning dissolution in the parts. This debility is not like common paralysis; the latter is a wasting of power in the muscles, from a want of stimulus; but this is a real disease from irritation. It is perhaps reducible to a species of sympathy similar to general hectic, from a local disease, and it may be called local hectic; but it sometimes goes beyond hectic, even to mortification. Effects of local diseases on Joints.—Joints that have a secondary motion with the diseased part, from having muscles common with it, may be included These joints gradually creep into the middle state of motion, but sometimes beyond this, so as to be more bent. Thus, the thigh is often bent forward, and also drawn more inward, so as to be immoveable, from diseased loins or hip. The knee also is frequently affected, even as if it was itself diseased. The limb first wastes; next is oedematous; and afterwards often inflames and 292 HUNTER'S PRINCIPLES OF SURGERY.

suppurates, which is sometimes very extensive. From continuation of one position, and want of action in the antagonist muscles, the joints, from necessity, become unfit for motion, and are afterwards often very imperfectly restored. Exfoliation.—This is the separation of a dead bone from the living, and is not generally understood. By the term we should be led to suppose that only the common separation of scales from a bone was meant, for the other exfoliations are not answerable to the term. We have many opinions of this process from different authors, but all very imperfect. The bone that separates cannot come away by rotting, for it is only dead, and not in the least putrefied. Bone is composed of two parts,—an animal substance, and an earthy substance intermixed with the animal. Hard bones, and the hard part of bones, have a larger proportion of earth than the soft or spongy bones; they have also fewer vessels. When apiece of bone becomes absolutely dead, it is then to the animal machine as any other extraneous body, and adheres only by the attraction of cohesion to the machine. The first business of the machine, therefore, is to get rid of this cohesion and discharge it. For effecting this separation there are several natural and successive operations going on. The first effect of the stimulus is on the surface of the living bone, which becomes inflamed ; whether new vessels are formed, or the old ones become larger, is undetermined; but by injecting the surface of the part it appears evidently much more vascular than the other parts. The surrounding parts also inflame, as the periosteum and cellular membrane, and often take on ossific inflammation. This produces another process: first, absorption of the earthy matter, and all the surface between the living and dead parts of the bone become as soft as if steeped in acid, while the dead part remains as hard as ever. To complete the separation, the absorbents continue their office, and absorb the living parts also, and the first process is in a small degree attended with the second. The operation of separation does not take place equally; it begins at the circumference, and continues on to the centre; and before the centre has begun the absorption of the earth, the circumference has begun the second. This progressive process in the suppuration causes the exfoliation to be tedious, so that the centre is the last place that separates. In pretty broad exfoliations, long before the centre has gone through the operation, the living parts perform their office, in producing granulations from the surface, and continue, in proportion to the waste, to fill up the space. When the dead part is wholly loose,'it is, like all extraneous bodies, pushed up to the surface. It often happens that the granulations ossifying, the exfoliation is locked in at the edges, thus giving it the appearance of internal exfoliation. Thus, while Nature is busied in getting rid of that part of the bone which is dead, she is laying on additional bone on the outside, the intention of which seems to be that of keeping up the strength of the bone, which would, without this addition, be lessened by the loss of sub- OF THE DISEASES OF BONES AND JOINTS, ETC. 293

stance. This opinion is, I think, supported by this circumstance seldom occurring in this manner in any bones but those of the lower extremity, which support the animal. If this is true, it is a curious process, by which Nature endeavours to support the strength of these bones during a loss of substance, by throwing on the outside bone in proportion to the loss of substance within. Nor is the process by which this adventitious bone is afterwards removed less curious, and the piece of dead bone set at liberty ; for from all that living bone adjacent to the dead piece, granulations arise, which push up the dead piece against the upper sides of the cavity; and in consequence of this pressure against the newly formed bone, the absorbents are set to work to remove it, and in proportion as this is absorbed the piece is pushed out, the granulations filling the space behind it. That in the separation of a dead piece a part is absorbed, I think is very evident; and that there is a loss of substance at the time of separation is obvious from this circumstance, that if a circular piece is taken out of the skull, and the circular edge of the remaining bone has its life destroyed by the actual cautery, to any distance, this deadened part will separate and come away, which it might not be able to do without a loss of substance between the living and dead bone. Another proof of the loss of substance in this supposed case is, that the side of the circular piece which is separated will retain its spiculae, while the edges of the remaining bone, so far from corresponding with them, are quite smooth. Now, as there is room in this circular hole to allow the ring of bone to come out, its regularity cannot be the effect of new matter added between the spiculas, but is in consequence of the absorption of those spiculae. It appears from this last supposed case that it is my opinion that the absorption is of the surface of the living bone; but I by no means wish to be understood that no absorption of the dead piece can take place ; for, on the contrary, I believe that Nature sometimes finds it necessary to the completion of her process; it generally takes place when the separation is slow, and the granulating process is quick, This absorption of the dead bone takes place in the fangs of the shedding teeth. [See note, p. 50.] The first appearance of separation is an alteration in the part round the exfoliating piece. This alteration is first a sponginess ; next, its becoming fuller of little holes; then a small groove is produced, a kind of worm-eaten canal about the thickness of a shilling, becoming gradually deeper and deeper: and the depth is irregular, according to the extent of the original cause. The small holes appear at first in the surrounding parts, and these appear more vascular, the more so the nearer the diseased bone. Sometimes parts become dead without any change of colour, dying almost suddenly, perhaps by exposure or a blow, and the surrounding part becomes spongy; the dead portion then looks the soundest; but when killed by previous diseases it is black. It is astonishing to see what little curiosity people have to observe the operations of Nature, and how very curious they are about the operations of Art. 25* 294 HUNTER'S PRINCIPLES OF SURGERY. After exfoliation, the living surface still continues soft until bone is formed. If it be a cylindrical bone, it has the appearance of a foetus's bone deprived of its epiphysis: it is hollow, but fills like a growing bone, in every respect, by bony matter deposited. Hard bones exfoliate quicker than soft, and the harder parts of soft bones sooner than the soft: the bones of full-grown people sooner than those of the young.* If you lay a hard bone bare to any extent, it always dies, but not always if the soft ones. Situation has the same effects as in other diseases: in the foot or leg it is slower than in other parts less removed from the centre. In exfoliations we often find considerable pulsations in the matter, lying in a hole which communicates with the granulations, which are formed under the exfoliating bone; sometimes it is hardly perceptible; this will depend much on the state of the granulations, their health, fulness, &c.; if all these are joined, the pulsation is very considerable : also according to the proportion which the size of the hole bears to the granulations underneath. After trepanning, the whole expansion of the arteries of the brain becomes visible, by being seen at one point: so it is with granulations, when the quantity is considerable in proportion to the hole. This depends on mechanical principles; so it is with mercury in a thermometer; we see it rise when in the stem, while in the ball it would be invisible. Exfoliation from accidents,—as from a blow, which is often of sufficient force to kill a sound portion of a bone, as in compound fractures, gun-shot wounds, at the ends of bones after amputations, &c, all of which do better than when it arises from diseased parts, the common processes of separation being carried on more vigorously. Exfoliation from Disease, as Caries.—Disease is often carried so far as to produce death in a part of a bone, and exfoliation is often very salutary, but not always so. Surgeons have endeavoured to cure a diseased bone by killing it: but this is often not so salutary as when it is spontaneous; for in the latter the whole diseased part generally dies; but it is often the contrary, or partial, when it is produced by art. The actual and potential cautery have been used for this purpose, and the practice probably arose from an idea that all diseased bones were disposed to separate by exfoliation, and that this would hasten it; but exfoliation is not, as has been supposed, a necessary consequence of disease in a bone, but it is the death of the bone which makes exfoliation necessary, to separate the dead piece. Now caustics neither hasten the process of separation either here or in soft parts; but the actual cautery, indeed, often has the power of inflaming the living surrounding parts, which invigorates and stimulates them to what they were

* [The great attention which Mr. Hunter bestowed on all matters connected with diseases of the bones entitle his opinions to the greatest respect. Believing however, that the bones afford no exception to the general principle, that the actions of parts are vigorous and rapid in proportion to their vascularity, I am compelled to dissent from the fact expressed in this paragraph.] OF THE DISEASES OF BONES AND JOINTS, ETC. 295

before incapable of, its use in this, and its superiority to the potential cautery not being commonly known. When the actual cautery can deaden the whole diseased part, a cure may be expected ; when art is to be used it is uncertain, as the quantity of disease in a bone can seldom be known : however, at times it may be guessed at, and as the seat and thickness of the bone vary, the cautery must be varied also. If the bone is diseased deeply, the cautery should be much heated, and very thick, so as to retain its heat longer: but these means are often insufficient, and the disease goes on teazing the part a long time, particularly in the lower extremities. In cauterizing, it is better to burn beyond the diseased part than not enough. But its frequent failure has occasioned the use of it to be much laid aside. Situations of Exfoliations.—There can only be two species of exfoliations, viz. external and internal; but they are often mixed, and then admit of a third kind, which I call the inclosed exfoliation. The external arises from internal causes, and is in many parts a simple operation, meeting with no obstructions, as in the head, ribs, &c. But in the extremities it is often complicated, and becomes inclosed, and then appears as an internal exfoliation. Internal Exfoliation.—These less frequently arise from accidents than the former ; but may arise from the two last suppurations of bones. The part which is to be exfoliated loses its life, and ulceration goes on in the internal surface of the surrounding living bone, to make room for the exfoliation. In internal exfoliations a part of the centre of the bone becomes dead, while the enlargement of the cavity lessens the substance of the surrounding part, and consequently weakens that part. But Nature wishes to furnish a substitute ; for the stimulus of weakness being felt, the surrounding parts become affected, and undergo the ossific inflammation, by which the bone is thickened; and this continues in proportion, and as long as the internal part is unremoved, or not cast off. Mixed Cases of Exfoliation.—The first is when an external one appears to be internal; the second is an exfoliation of the whole thickness of the bone in one part; the third of the whole bone. These I call inclosed, or incased exfoliations, generally occurring in the lower extremities. These three being different at first, are not very easily conceived. First species of Inclosed.—Sometimes when the surface of a bone becomes dead, before the separation of the piece of bone takes place, the ossific inflammation comes on, and entirely covers the exfoliating piece, leaving only a little hole for the discharge of matter. This takes place, first, when the periosteum is inflamed, and the granulations from the edges of the exfoliated pieces also ossify; but the process for freeing the portion of bone has been described already. The second species is when a piece of any given length becomes dead throughout; the appearance of internal exfoliation is here 296 HUNTER'S PRINCIPLES OF SURGERY. still stronger than in the last case. Exfoliation or separation begins on the living surface of contact, at the two ends of the dead bone or piece, and ossific inflammation comes on in the surrounding parts, so that it becomes incased. This rarely happens, but when it does, the separation of the exfoliated piece is very tedious, as the stimulus is given to all surrounding parts. The third species is where the ossific disposition takes place in the soft parts, from end to end, and the whole becomes inclosed in a case of bone. The difficulty lies in conceiving how it becomes inclosed at the ends where the joints are constituted; but probably it is from these ends being alive, and exuding coagulable lymph from their surfaces, or else from lymph being exuded from the surrounding ligaments, and that becoming a basis, so as to keep the joint complete. Of extracting Exfoliated Bones.—As it is uncommon for parts to heal before the exfoliated pieces are extracted, or if they do heal, not to break out again, their extraction becomes proper, if practicable ; but this is often difficult in many cases, from the situation, as also from the obscurity respecting the real circumstances, of the exfoliated piece: but in internal and in the incased kinds it becomes still more difficult, even though all the circumstances attending the exfoliated piece were known perfectly. The surrounding soft parts render many things respecting bones obscure; but wherever the bones are found loose and bare, attempts should be made to remove them. The pressure of a probe on a piece of bone will generally satisfactorily inform you if the part is detached, by its mobility. If detached, we may often gain time by removing it, and in general this is proper and the best practice. If it does not allow of a removal from its extent, it is best to break the exfoliated part into pieces: though it may be often difficult to ascertain this, as the edges are often covered with surrounding soft parts. The internal exfoliations, and also all the mixed species may be often assisted: but the difficulty lies in ascertaining the state of the incased piece, without which little can be done, nor should much be attempted. In the internal and mixed, which are not only covered by soft parts but also living bone, it will be difficult to ascertain. In mixed cases it may be evident that exfoliation has taken place, and is incased by bone; and for such, a dilatation must in order to expose some of the living bone. The next thing is to separate the dead bones; probably some of the living bone must be sawed through, (the best saw for which purpose will be one in form of an axe,) to allow of the extracting the dead pieces and such living parts as are broken off, which often happens; or the dead must be broken into many pieces. Both these I have done, as I will illustrate by a case. A young gentleman had an abscess form about the middle of the arm: when this was opened, the bone was found bare. It was opened in two places; first, on the outside of the arm above, and OF THE DISEASES OF BONES AND JOINTS, ETC. 297

next on the inside below. The openings did not heal, and the bone could plainly be felt at both. He had been in this way some years, when he came to London. On examining the parts I could plainly feel the bone with a probe, and move it upwards and downwards a little, but at the extent of each motion it seemed to be fast. It was plain that the bone should be removed, if possible ; but how was it to be done? I chose to expose the bone at the upper and outer orifice, this being less engaged with the nerves, vessels, &c, and also being more convenient to operate upon. An incision was made on the bone downwards and forwards on the outside of the biceps flexor; the end of the exfoliation was exposed, as also the upper part of the bony case. I followed this downwards and obliquely inwards, and when I had exposed the whole, I sawed it, in the direction of the exfoliated bone, to the exfoliation itself; but as this did not open so as to allow the disengagement of the bone, I put in the spatula to force it open, but could not; however, I did it in part, so as to get a wedge of wood into the opening, which kept its position. The next time I forced it open a little more, and pushed in a thicker wedge, and in two or three trials more I was able to bring out the exfoliated bone. It was a piece of the middle of the os humeri, about three inches long, and of its whole thickness. Of Rickets, or the Constitutional Defects of Bones.—This complaint would appear either to be a fault in the general constitution, or in the principle of the formation of bones themselves ; but as it is peculiar to one class of constitutions, which are all weak ones, it might be thought to arise from weakness. If weakness is necessary to produce this disease, it must be one attended with a peculiar disposition. And this is probably the case; for we can hardly suppose that such a disposition in the bones could produce this species of constitutional weakness. However, as it is a weakness attended with a disposition of a particular kind, it is possible it may arise from this fault in the bones, so far as the constitution sympathizes with the state of the bones. It is of a particular kind, as all weak people are not affected with it. This peculiarity of disposition, I suspect, is somewhat of a scrofulous nature, at least the two effects are often found in the same subject, whether the causes are the same or not. It would appear to be a want of power in the bones, or of disposition in their vessels, to form calcareous earth and animal matter, but less of the last than of the other. It is most common in young subjects, and is generally attended with enlargements, and the bones often bend from the incumbent weight. From the increase of size in growing subjects, it would appear that the proper quantity of earth is the cause of the limitation of size of bones, or that the bone has a greater freedom of growth when not checked by a due quantity of earth or its own solidity. This is more perceptible in the joints, as they are there softer than in other parts, and hence these parts are most subject to this disease. It is only in young and growing bones that this increase of size from the 298 HUNTER'S PRINCIPLES OF SURGERY.

deposition of the two substances can take place, it being only an effect; but a full-grown person may be rickety without any increase of size, their bones not admitting of it. The definition of rickets, then, is a deficiency of earthy matter in growing or full-grown bones. In the adult we see the bones bent by the action of the muscles. But the cause in the adult is different, it being a disposition to remove what is already formed and deposited by absorption ; however, a disposition to absorb would appear very different to a want of disposition to deposit, and may probably arise from a very different remote cause; for though the effect is similar, yet I can conceive both to have the same original cause. If a softening of the bone is to be the disease, it is only taking place by two different means ; for as there is probably a constant replacement of the earthy matter, this disease may arise in adults from a want of power or disposition to supply the place of that which the absorbents remove. Of Rickets in Adults [mollities ossium*].—The disposition to absorb the hard substance of a bone, or the disproportion between the process of deposition and absorption, which produces rickets in adults, is often in a much greater degree than in young subjects; for in the most rickety child I have always observed some earth in the bones, but in adults I have seen the bones become as flexible as a tendon almost. In different parts of the bone we find different dispositions ; but the disposition of absorption gets the better of the ossific disposition in other parts of the bone, or of the disposition to deposit earth. Of the Effects of Mechanical Pressure and Muscular Contraction on Rickety Bones.—The bones are often bent by mechanical pressure of the body, and by muscular actions, into very peculiar forms,

* [Mollities ossium differs from rickets in respect of the age at which it occurs, being a disease of adult age affecting the whole of the bones, whereas rickets is a disease of childhood which is principally manifested in the bones of the lower extremities and spine, and but rarely in the bones of the pelvis or upper extremities. They agree, however, in this, that when a section is made, the bone is found to be more cellular than usual, the cortical part is reduced to a mere shell, the cells are filled with a bloody or gelatinous-looking substance, and the deficiency of earthy matter is such that the bone is easily divided with a common knife. Dr. Bostock found in some instances of mollities ossium that the quantity of earthy matter was not more than one-fifth, instead of being two-thirds of the weight of the bone. It may further be observed that the disposition to mollities ossium is rarely overcome when once formed, but the disposition to rickets is generally worn out as children grow up ; and, in proportion as this happens, the long bones at the seat of curvature are found to be flattened laterally and strengthened on the concave side, where the support is required. Fragilitas ossium, depending on the superabundance of the phosphate of lime in old people, accompanied with a disposition to ossific deposits in the different structures of the body, may be considered as a vice of nutrition of the opposite kind. A remarkable case of this sort of ossific transformation of the muscles and other structures is preserved in the Hunterian Museum, in which the movements of the patient must have been as effectually manacled as by the enchanted wand of Comus.] OF THE DISEASES OF BONES AND JOINTS, ETC. 299 and often impede the actions of other parts. The joint forms a more acute angle than it would in health, and then the muscles get a greater power of action. It is most frequent in the back-bone, pelvis, and thigh-bones, in the angle made by the cervix femoris, knee, tibia, &c. In these it is most frequent, from the two powers acting (viz., weight and muscular action). The ribs are made straight, or rather bent inwards, by the pressure of the atmosphere, so that the child can hardly breathe ; a bad formation of the skull will affect the senses; crooked spine will affect the health from an alteration in many of the viscera. In the female pelvis many dreadful consequences occur in delivery. When a bone has admitted of a bias, a disposition takes place on the side unnaturally pressed, for a deposition of bone, so that we find a bony substance formed there which acts as a prop. In the leg the bone is bent forward from the muscular action behind. We have seldom these bends in the upper extremities, as only one of the powers is acting, viz. that of the muscles : however, they are sometimes bent, as an example of which an os humeri was shown. In the thigh the curve is generally forwards and towards the upper part, as was seen in an os femoris in which Nature had deposited a quantity of earth on the concave part. Rickety people are generally knock-kneed, from one condyle being less than the other; it always is somewhat less, unless in bow-legged people. Bow-legged people are in fact straightest with respect to the bones, the femur and tibia in them being in a straight line. Of the Cure.—The cure is not yet discovered, nor is the preventative^ of absorption in the adult yet known. The original cause being the same in both, the treatment should be the same. The indication is to give strength and tone to the system by bark, sea-bathing, &c.; but these only seem to give general health. However, I have the greatest opinion of sea-bathing, bark, and chalybeates. Of Exostosis.—This is in a great measure peculiar to youth. It is an increase of bony matter in particular parts of bones. It is of two species: one is local, and may be supposed to be similar to many tumours growing in the flesh, and probably may occur in any constitution; the other requires particular constitutions, and seems to be constitutionally interwoven with the formation of bones in such people. They are principally connected with the soft parts of bones, appearing generally at their extremities. When universal, the whole soft parts of the bone| are affected. It sometimes appears suddenly, and is of various figures, sizes, &c.; but sometimes it comes on gradually and increases gradually. These protuberances often sWell to a considerable thickness beyond their origin or attachment, by which means a small neck is formed. Sometimes they have a power of growth within themselves, and do not in all cases continue to grow from their origin. Sometimes it affects only one bone, at other times almost every bone in the body. It is a shooting out of bone from a bone, as the horns of a buck's 800 HUNTER'S PRINCIPLES OF SURGERY. head. It is not the effect of ossific inflammation. The substance of the bones in these constitutions is often enlarged in the _ soft parts, as in rickets, which leads me to suppose the same original cause is common to the two diseases. When near the joints it often produces lameness, and disturbs the action of the muscle so as to alter the motion of the joint. The cases of a gentleman and lady were mentioned who were subject to the former of these processes, which was very troublesome; the lady was evidently scrofulous. Cure of Erostosis.—As it appears to be more connected with the natural formation of bone than with disease, it is of more difficult cure than if it arose from disease; for disease is always producing action tending towards a cure. It is hardly ever to be cured by medicines either external or internal; but as it is sometimes spontaneously removed, we should endeavour to promote the absorption of it, by rousing up this power. If, however, we are not masters of this power, and we know of no such, they may be removed by art, if this can be done with safety. The situation first should be well understood, and the parts covering it well known. The instrument must be adapted to the kind of exostosis and to the situation; the common ones are a saw, cutting pincers, and chisel. First lay the part bare, either by removing a part of the integuments, or by making the incision somewhat longer than the tumour, so as to make more room, after the separation of the lips, for its removal. If anything more than skin covers the exostosis, as muscle, it should be only divided, not removed. When there is a hard root, and deeply situated, a cutting pincers or chisel is necessary; but if superficial, as on the tibia, it may be sawn off. I have removed them from under the deltoid muscle, and also from the tibia. The immediate dressings must be suited either for healing by the first intention or by granulations from the bottom of the bone. If the first, exfoliation may take place ; but this is of little consequence, therefore it should generally be attempted, as it frequently will succeed ; and if not, suppuration ensues, and it is easily and speedily thrown off. Diseased Exfoliations of Cartilages.—Cartilage is a peculiar animal substance, and composed wholly of animal substances, coming nearer to horn than any other structure. I divide them into two kinds: first, such as constantly change into bone at a certain age; secondly, such as do not change into bone, as that of the nose, ears, &c. They appear to have but weak powers. When there is a fracture, the union is bony by ossific inflammation in the cartilages, which change into bone; but in the permanent cartilage there is a renewal of its own substance. Sometimes the inflammation goes on to suppuration; but they seem to have insufficient power to admit of ulceration: yet they may be absorbed by the absorbents of other parts; as in white swellings, when suppurated, the cartilaginous ends are removed by the absorbents on the surface of the ends of the bones that the cartilage covers. OF THE DISEASES OF BONES AND JOINTS, ETC. 301

It may be ulcerated in this manner in other joints also; in the knee we find all the different stages of absorption of cartilage; granulations will shoot from under, through the cartilage, and sometimes when there is not much matter in the joint, these granulations will inosculate and form a bony union. [Preparations of cartilage were shown peeling off the ends of bones.'] Changes of Cartilages of Joints by exposure.—The only effect seems to be that they become softer, which is occasioned by interstitial absorption, which sometimes proceeds so far as to remove the whole and leave the bone bare; a case of which was given in the finger after amputation. When the cartilage is exposed, the surrounding parts granulate and surround the cartilage like a purse, not adhering to it for some time after the wound is healed, for cartilages will never heal by the first intention. A woman had her arm amputated at the shoulder-joint, with a flap by Mr. Bromfield ; and in two years afterwards she died of a fever in St. George's Hospital. Upon examination, I found that the cartilage had not adhered to the flap, which in that part had a smooth surface ; nor had any granulations arisen from the surface, which appeared unaltered. Exfoliation of Cartilages.—The separation of a dead part is called exfoliation, for there can be no ulceration of cartilage. However, this is very uncommon, as the absorbing powers are very deficient in cartilages to remove dead parts. I have never seen it. I have seen them black and dead, but then the whole cartilage came away, together with the end of the bone ; therefore it could not be called exfoliation of cartilage from cartilage, but of bone from bone. But the cartilages are capable of being absorbed from the granulations formed under them on the surface of bones. The permanent cartilages are just similar in their separation, &c. I have seen them separated in sores of the part, as the nasal cartilages. 26 302 HUNTER'S PRINCIPLES OF SURGERY. CHAPTER XIX.

of hemorrhages and aneurism.

Causes of hemorrhage.—Hemorrhage: 1st, natural; 2d, diseased;—arising from irritation ;—stimulating styptics to be avoided ;—occurring on membranous surfaces;—3d, from wounds;—checked by contraction of arteries; —artificial modes of checking hemorrhage ;—oil of turpentine.—Coagulation of blood;—stretching of arteries;—ligature ;—modes of applying it.—Secondary hemorrhage. Of aneurisms ;—true and spurious ;—different kinds of each according to authors ;—divisions fanciful;—definition of an aneurism.—Cause of aneurism; experiments on coats of arteries.—Situation of aneurisms.—Action of heart not the only cause of aneurism ;—local disease in the artery; and want of equable support round the vessel.—Natural cure of aneurism from obstruction of the artery;—oedema of the limb ;—sloughing of the skin over an aueurism. —Treatment of aneurism.—Objections of Pott and Bromfield to operations for aneurism.— Strictures of the latter on Mr. Hunter's operation.—Necessity for early operation;—improper practice of waiting for the dilatation of collateral channels.—Mr. Hunter satisfied of the propriety of his operation ;—arteries on which it might be practised.—Mode of operating where a tourniquet cannot be applied ;—when it can.

From what we have said of the blood, it must appear to be of great consequence that it should be distributed to every part of the body in its due proportions ; but in disease a much nicer proportion is necessary than in health. Effusions of blood arise from three causes: 1st, from natural causes ; 2dly, from disease ; and 3dly, from violence. Of the first species is the menstrual discharge. The second kind arises from many diseases both constitutional and local: those from the constitution are numerous, as bleeding at the nose, &c, which often appears to be a species of derivation, or the effect of a diseased action on this part, as is sometimes the case in piles, where they may be considered as produced by the constitution ; those from local causes may be called spontaneous, as bloody flux, bleeding from piles, vomiting or spitting of blood, diseased menses, &c. The third proceeds from violence, destroying the continuity of the vessels, among which must be classed aneurism. Of Hemorrhage from Disease.—At present I shall only speak of the second and third hemorrhages, from disease : these I have divided into constitutional and local. The constitutional should in general be encouraged rather than checked; but the local are next to our present purpose. The local arise from two causes: 1st, from a peculiar irritation, which can be cured only by quieting the irritation; or, secondly, from a species of relaxation, or want of power or action, in the vessels of the part. The first I have seen in many operations, when a new irritation had taken place; as OF HEMORRHAGES AND ANEURISM. 303 when the divided vessels had contracted and checked the bleeding, they have opened again on the application of a cautery near them. The intention of this would appear to be the removal of the extraneous body; it also occurs in many wounds and sores which do not secrete good pus, but pus mixed with blood. For the cure of this species, instead of styptics, we should apply sedatives, the best of which is opium; and sometimes, probably, solutions of lead. The effect of these will be according to the peculiar irritation. A boy, for instance, had a bloody sore on his shin from an accident, for which he first used a common poultice; but as it still continued to bleed and not to heal, I ordered a poultice made with poppv-head decoction, under which it went on well, and soon healed. Nothing affects the system more than too great a loss of blood; the body becomes languid and cold, and the heart seems disposed to suspend its action, as if a natural method was instituting to stop the bleeding, and also to keep the actions of the machine proportionate to its power. But I know not what the cold sweating is to do. An animal cannot subsist long in this state but the constitution will begin to rouse up its actions again; there will be a full pulse and seeming strength; but if the weakness is very great, this apparent action or reaction of the system does not long continue. When the pulse is strong and the body warm, it would appear an indication for bleeding; but this is improper, and the loss of a small quantity of blood at this time would probably kill the patient.* The rising of the pulse in hemorrhage is often an effort of Nature to live, and cannot be reduced, although it still further increases the irritability of the system. Hemorrhage from the second cause always exists in the small vessels, and commonly in the membranes of some outlet or excretory duct, and also in sores which have become in some measure like those secreting surfaces. It probably arises from a want of disposition to contract. The cure is the same as that from violence viz. the application of powdered resins, oleum terebinthinae, and other styptics. Of Hemorrhage from Violence.—All wounds do not admit of union by the first intention, as when a large vessel is wounded, when the second mode of union is necessary. But large vessels are sometimes wounded without much harm, which either depends on the mode of division, or their situation with respect to surrounding parts. The bleeding from vessels has in many cases a good effect, as in fractures, and is then in small quantity; but when copious it hinders this salutary effect, as is sometimes the case in simple fractures, and commonly in compound. The suppression of Hemorrhage is effected by three modes, viz. the natural, the accidental, and the artificial.

* [Dr M. Hall has amplified on this observation in an able paper in the seventeenth volume of the Medico-Chirurgical Transactions, in which he has pointed out the dangerous consequences which may arise from mistaking the reaction consequent on repeated losses of blood for an indication for further depletion.] 304 HUNTER'S PRINCIPLES OF SURGERY. The first is from the contraction of the muscular coats of the arteries: this power is one of the natural ones, and the accident is the cause of this contraction by its stimulus. It is most powerful in the small vessels, as the blood's motion is less in them; but even in large vessels it is considerable. I am of opinion that an amputation below the knee in most cases would not kill by its hemorrhage, even if left to itself; but this experiment can only be ascertained by accident. The artery in the thigh of a boar stopped bleeding before the animal was at all weakened, and the carotid artery of an ass also stopped bleeding after being divided: but I believe that the arteries of most animals have more of this power than those of man. It sometimes appears as if this contraction was not permanent, but relaxed and contracted at intervals; but when vessels repeatedly bleed there is probably a want of contractile disposition, for then the whole surface is bloody, and the patient becomes very weak from the loss of blood, and often dies. This contraction of the vessels can be increased or diminished according to circumstances. The first cause of increased contraction is exposure, which is very evident in operations; for when the wound is dressed it will bleed again, and again cease when exposed, so that here the contraction must be from exposure. 1 conceive that leeches occasion a free discharge of blood by their having a specific power or acting as a poison on the vessels, so as to weaken them and prevent their contraction thereby. The assistance which may be given to the natural contraction is by means of stimulants, which, however, can only affect the small vessels; their action is simply stimulating them to contraction. Whatever stimulants are used, they will be assisted by the power of the vessels and their sympathy with each other. A dossil of lint dipped in oil of turpentine, after having first wiped the wound clean in order that it may reach the vessel, is the best, and may be renewed pretty often. I have seen it immediately stop vomiting of blood from the stomach after all other means had failed [see p. 254], given internally with white of egg as often as the stomach would bear it. In external hemorrhages where it had not the desired effect applied externally, I would give it internally: it is the best, if not the only true styptic; thus, in a case of nasal hemorrhage which nothing would stop, I gave ten drops of oil of turpentine in a draught, and repeated it every two or three hours, which entirely stopped the bleeding in less than twenty-four hours, and it never returned.*

• [It is scarcely necessary to observe, in the present day, that this eulogium on the oil of turpentine is unmerited. Of external styptics, (if any really deserve that name,) a saturated solution of alum is much to be preferred ; and certainly no internal medicine has equally acquired the general confidence of medical men as the superacetate of lead conjoined with opium. The arrest of hemorrhage is attended by the following circumstances : 1st, the retraction of the artery within its sheath ; 2d, its diametrical contraction ; 3d, the effusion of blood into the cellular spaces between the vessel and its sheath ; 4th, OF HEMORRHAGES AND ANEURISM. 305 The second, or accidental, mode is of two kinds: first, the coagulation of the blood as it flows, not within the mouths of the arteries, as has been always described by authors, but around them. This can only take place when the arteries can contract a little into the surrounding cellular membrane by which the blood is divided, and this assists its coagulation; and the pressure of it on the mouths of the bleeding vessels assists in stopping the hemorrhage. This disposition can be increased by spongy bodies applied to the mouths of the vessels; in some cases lint is sufficient, and flour will assist the lint; cobwebs also are useful on the same principle, and the process of coagulation will also be increased by agaric, from its increasing the surface of coagulation, as well as by its pressure on the vessels ; but these can only be useful in wounds of small vessels, where the circulation is slow, so that the blood can coagulate, and are improper in wounds of the larger vessels. The tourniquet may be applied here, but it should not be twisted too hastily. Another mode arises out of, the natural, and may be considered in some degree as natural. It is a property in flexible bodies to have their diameters contracted as they are lengthened ; in arteries this might be carried to a great degree when permanent effects are to be produced. It is necessary that they should be lengthened so much as to destroy the contractile power; for this is the way Nature takes to stop the bleeding of ruptured vessels. Thus we see that arteries which are lacerated will more readily stop bleeding than if cut with a sharp instrument, as was proved in the case of the miller related by Cheselden; and this is the wray Nature takes to stop the bleeding of the navel-string in beasts. Surgeons do not take advantage of this; but farriers and gelders do, as their practice of tearing the artery through in gelding animals shows.*

the formation of a coagulum or plug within and around the vessel; 5th, the effusion of lymph; and, lastly, the contraction and obliteration of the cavity of the vessel to the next principal branch, and its final degeneracy into a ligamentous cord.] * [The principle of torsion, as practised by several of the French surgeons, is precisely the same as that which is here laid down in respect of lacerated arteries ; that is, the extremity of the artery is drawn to a point, and does not return to its original calibre, in consequence of the destruction of its elasticity. We may also further add, that the rupture of the internal and middle tunics, which generally happens on these occasions, will tend to occlude the mouths of the vessels still more completely by entangling the blood among the lacerated fibres and promoting its coagulation. But how far the first of these effects, or the obliteration of the calibre of the vessel, depends on the destruction of any vital property, as of muscular contractility, may well be questioned, since the same effect takes place on dead arteries when similarly treated. A preference is given by some surgeons to this means of arresting hemorrhage, inasmuch as it obviates the necessity for ligatures, and does away therefore with one cause of obstruction to union by the first intention. Torsion, however, is objectionable : 1st, because it cannot generally be depended on where large arteries are concerned ; and 2dly, because it requires a considerable isolation of the vessel from the surrounding parts, and sometimes leads to a sloughing of the extremity of the artery, which must operate as a much more dangerous foreign body in the wound than a simple ligature.] 26* 306 HUNTER'S PRINCIPLES OF SURGERY.

Of lateral Wounds in Arteries.—The lateral wounds in arteries are commonly, though improperly, called false aneurisms, on account of the formation of a tumour with pulsation; it having been supposed that only the external coat of the artery had been wounded, and that the internal had given way in consequence of having lost the support of the external coat; but the fact is that the blood escapes into the cellular membrane, and, coagulating there, forms a kind of sac, cutting off all communication with the other cellular membrane, and, assisted by external pressure, may stop the bleeding for the present; nay, the wound may heal up by the first intention; but by constant and increasing pressure, the surrounding cellular substance, containing the Mood, by degrees gives way and forms a perfect cyst. These may be divided into two stages; first, while the case is yet recent; secondly, when the cyst is formed. The first of these will either kill or come to the second, if not operated upon; after which, if the operation is not performed, the patient must die; therefore it is best to perform the operation as soon as possible, as the second will also kill if not operated on. In the first stage, then, if possible, the artery should be taken up. The operation is very simple: first apply the tourniquet, then lay the artery sufficiently bare, and tie it above and below the wounded part; the part included between the ligatures will, when it becomes dead, slough off, therefore does not require to be cut out. The ligature should be first made on that side of the artery next the heart, and the tourniquet then slackened a little, to satisfy the surgeon of its safety; afterwards the whole should be dressed as a recent wound. Of the artificial Means of stopping Hemorrhage.—The method is to stop the mouths of the bleeding vessels; but this is often very difficult, on account of the vessels being hid by being deeply-seated, and is made more so by the continuation of the bleeding, especially in a part where a tourniquet cannot be applied. I shall consider the artificial means employed for this purpose under two heads: 1st, chemical; 2d, mechanical. The first acts by destroying the natural texture, and of course the life, of the mouth of the vessel. The most powerful of these is heat, viz. the actual cautery, which should not be too hot, nor should it indeed be used at all unless other means fail. It acts by drying and coagulating the blood, and destroying the life of the part to which it is applied.* The iron should be thick, not too short, as large as the part will admit of, of a reddish heat or approaching to it. Concentrated acids have been applied with success, and whatever assists in coagulating the fluids, as ext. saturni; and I have sometimes thought of trying boiling water. The mechanical method of stopping bleeding is by compression, and is the most secure: we therefore have recourse to it when * [Besides this, the actual cautery corrugates and shrinks the animal textures, by which the bleeding orifice is obliterated. A similar but less powerful effect s produced by the mineral acids.] OF HEMORRHAGES AND ANEURISM. 307 every other means has failed. It consists in inclosing the vessel in a ligature. The spasms and convulsions which appear after operations, have been attributed to the nerve being inclosed with the artery in the ligature; but this seems false, it being only in particular habits that such symptoms occur, patients more generally recovering after the use of the ligature with no bad symptom than otherwise. I have sometimes tied nerves on purpose along with the artery, particularly along with the radial artery in amputations of the fore-arm, and never observed that any bad symptom succeeded.* There are two methods of applying the ligature, viz. the needle and the tenaculum ; the last cannot be employed on all occasions, only under particular circumstances. But the needle admits of application on almost all occasions. It has been objected to as taking up surrounding parts ; but this is essentially necessary in old persons, where the arteries have lost their elasticity. An artery in the centre of a muscle should be taken up by the needle. The tenaculum should only be employed where we have sound arteries to deal with, and when these are situated in the interstices of muscles. If the artery is in the substance of a muscle, the tenaculum would take in more of the surrounding parts than a needle would do, and the ligature will be less secure. I think the ligature should be larger than it generally is made : the proper tightness is not easily ascertained ; but it should be drawn more tight in proportion to the bulk of the parts inclosed. The degree of force used in this case would cut through the artery alone. The size, consistence, and roundness of the artery, and quantity of surrounding flesh, must direct us in the force which is necessary to make the ligature. The thicker the ligatures, the greater surface they compress. In small arteries the ligature need not be tight, slight compression answering the purpose. Of secondary Hemorrhage after Operations.—This happens more particularly to the large vessels, and generally occurs a few days after the operation, owing to some circumstance or accident therein : the ligature not having been made tight enough, or else too tight; or from much surrounding parts being included, and some of these ulcerating, the ligature gives way. If there is not a loose tourniquet about the limb, the patient may soon bleed to death, or the bleeding lays the foundation of future disease, as lingering

* [It can scarcely, I imagine, be necessary to warn the reader against so slovenly a practice, which may be attended with the most painful and dangerous consequences. In every case it is desirable to secure the extremity of the vessel as distinct from the surrounding parts as possible, which will not only lessen the irritation, but be the best security against the occurrence of secondary hemorrhages. The ligature should be of as small a size as possible consistent with strength, and be drawn with sufficient strength to cut through the internal tunics, which will then heal as incised wounds in other situations : but an artery which is diseased or inflamed becomes brittle, and will not bear the same strain as a healthy vessel. 308 HUNTER'S PRINCIPLES OF SURGERY.

weakness or dropsy. This secondary bleeding is very difficult to be stopped, especially when granulations are formed, as the artery at the bleeding part cannot be seen. However, an anatomical surgeon will not be at a loss to know the situation of the vessels; but admitting this, even then, the taking up an artery far above the surface of the wound will be a considerable operation. It will be right however, especially if the extremity of the artery be supposed to be diseased, to lay it bare above the diseased part, and then take it up where it is sound. A. B. came into St. George's with a white swelling, for which it was thought necessary to remove the limb. Instead of granulations ulceration came on: the artery bled at times; but before any one could come to his assistance it would stop : at length, however, the bleeding was so great that he was considerably weakened, and soon died. Upon examining the limb the artery appeared sound, till we got within an inch of the stump, when it appeared black, and seemed to have lost its elasticity: the circumstance of the bleeding stopping and returning again, I am inclined to attribute to the patient's being low and faint at the time he was losing the blood, but returning again on the recovery of his strength. In these cases a diseased artery should be suspected ; and I think it would be best to dissect for the vessels, and see whether it be so or not, and if found diseased, to take it up in a sound part. It is recommended by some surgeons to make a strong compression on the stump, which may be done by means of a thick pad, covered over with tin, and applied to a screw tourniquet, to prevent bleeding; but I would observe that the long pressure of the tourniquet is painful and inconvenient. Exposing the stump to cold air will at times stop the bleeding. These secondary bleedings as far as my observation goes, happen oftener to the radial and ulnar arteries than any other. The artery not healing by the first intention may be attributed to various circumstances, as ossification, extreme weakness, or the neighbourhood of a considerable branch. Of Aneurisms.

The injuries and diseases of arteries, called aneurisms by authors, are so various as to render it impossible to give a definition of them. They have been divided into true, and false or spurious aneurisms. The true, by Le Dran, are divided into three kinds, and Heister multiplies the division greatly. Le Dran's first is a regular dilatation of the coats of an artery; 2d, where one coat has given way, and the other coat, unable to sustain the force of the circulation, allows itself to be dilated; the third is a mixture of these two. The false are numerously divided by Heister and others: one is a true aneurism burst; another is a wround in an artery, which will produce various effects according to the treatment, all of which OF HEMORRHAGES AND ANEURISM. 309 are called so many aneurisms; but I do not consider a wound in an artery an aneurism, even if an aneurism itself. Heister gives us the size of aneurisms as described by authors, which is only showing us the ignorance of those authors in allowing them to come to such a size before the operation was performed; but I wish never to see one that can be made the subject of an operation larger than a walnut before it is operated on. I have already shown that a wound into an artery is not an aneurism ; so that I conceive there is only one disease which is properly to be called an aneurism, viz., the first, or true : nor is this divisible into different kinds ; the second kind is only ideal; and the third is the consequence of one part of the sac giving way sooner than another. By an aneurism, then, I understand the dilatation of the coats of an artery, arising probably either from disease or accident, producing weakness, which becomes the remote cause, while the force of the circulation is the immediate cause. It probably may also arise, however, from a disproportion in the blood's motion, and then the disproportion between the force of the circulation and strength of the artery is both the remote and the immediate cause ; but this is probably only in the larger arteries, where the force is greatest. However, whatever may have been either the remote or immediate cause, it must in fact in all cases arise from a disproportion between the force of the blood and the strength of the artery, the coats being weakened so as not to be able to support the force of the blood in its passage along its canal, which therefore gives way. This weakness of the coats of the artery would appear, in most cases, to depend on disease; for accidents, cateris paribus, have generally the powers of recovery. As a proof of this, I will relate an experiment made to ascertain the truth of the existence of the mixed kind, which was supposed to arise from a partial destruction of the coats of an artery, and that the remaining coat being too weak to sustain the force of the circulation, gave way, and distended. That the artery might have the full force of the blood's motion, I chose the carotid artery, as being near the heart. One of the carotid arteries of a dog, for an inch in length, was laid bare, and its coats removed, layer after layer, until the blood was seen through the remaining transparent coat, and I had gone as far as I dared; I then left the artery alone for three weeks, when I killed the dog, expecting to find a dilatation of the artery, as had been asserted ; but to my surprise the sides of the wound had closed on the artery, and the whole was consolidated to and over it, forming a strong bond of union, so that the whole was stronger than ever. Mr. Cruickshank has, I think, produced an experiment in opposition to mine, where, after the artery was denuded and thinned, the parts surrounding it were kept from uniting with it, and an aneurism formed : but this experiment does not apply here ; for in yvhat instance could such an alteration be made in the artery, and the surrounding parts not unite to it ? So that the blood's motion 310 HUNTER'S PRINCIPLES OF SURGERY.

was insufficient to produce the proposed effect. The force of the heart, however, has some power in operating as a remote or first cause of aneurisms. Aneurisms are most frequent in the larger arteries, as at the arch of the aorta ; and more frequent in the second order of arteries than in the third ; but they are sometimes found even in the fourth or fifth. I have seen an aneurism of the arteria pudica where it was passing out of the pelvis, and in which we must suppose a previous disease of the artery, as the force of the heart is small. The nature of the artery contributes likewise, the structure of the large arteries being chiefly of elastic matter, and not near so muscular as the small ones, which have therefore greater powers of resistance. It would appear that there must be a specific disease of the artery in most cases, for dilatation is too local for so general a cause as the force of the heart. As aneurisms have hitherto been allowed to go on till they have either destroyed the use of the part, or killed, little has been known with regard to their nature or manner of appearance at first. Instances discovered in dissection have given us the only insight into their original appearance. In several which I have seen there was a pretty regular dilatation of the coats of the artery; but in many there was great reason to believe it began at one side. If we were to form our ideas of the first formation from the appearance of those of long standing, we should suppose the dilatation always began on one side; for when we open an aneurism that is very large, and examine the internal surface, we find that the coats of the artery are commonly still remaining on one side of the sac and not on the other; but I suspect that the appearance arises from the dilatation going on faster on one side than on the other after the artery has been considerably distended, which may arise from the vessel being not equally diseased all round, or being more exposed to the force of the heart on one side than another, or less supported by surrounding parts. From the knowledge of the greatest force of the heart in the different arteries, and from the knowledge of those arteries which are not equally supported on every side, let us see if we could not, d, priori, say where the swell would be, if such and such arteries were diseased on every side equally, and became considerably dilated. First, in those arising from the force of the blood's motion; for instance, when an aneurism takes place at the curve of the aorta the dilatation is upwards, because it is there that the blood pushes with most force, passing in a straight line when in the ascending aorta at the fore part, and when in the beginning of the descending at the back part. When in the carotids, the swell is outwards and forwards, because there is less resistance; in the subclavian, forwards ; in the axilla, downwards; in the abdomen and thigh, forwards; in the ham, backwards; but in the leg, on which the pressure on the artery is equal on all sides, it is difficult to say on what side the swell would be, and hence it is that the bones of the leg are so often diseased when aneurism happen there, caries or ulceration ensuing when the OF HEMORRHAGES AND ANEURISM. 311 dilatation increases to a considerable size. Even in the last-mentioned situation the force of the heart directs, in some degree, the swell of the tumour; but that is not until the sac is a good deal enlarged. The force of the blood against the most distant part of the sac endeavours to carry it on further in the direction of the motion of the blood, which in time makes a pouch; therefore it is elongated in the direction of the sound artery. The sac often, by its increase, presses on the sound part of the artery, and becomes the cause of its obliteration, as I have seen more than once. Hence the blood becomes irregular in its motion, and has time to coagulate, till the sac becomes filled with coagulum, which is strongest and densest on its external surface. The coagulation takes place at the most distant parts from the direct current of the blood; the firmness and colour of the laminae in different parts of the tumour are such that it is easy to distinguish an old coagulum from a new one ; the external laminae are of a dusty brown colour, and these laminae grow gradually redder as we advance inwards towards the current of the blood. As the dilatation increases, the coats of the artery are either thickened by the thickening process, or the cellular membrane already thickened becomes firm, and adheres from a consciousness of weakness. When the aneurism proceeds to this state it generally gives way to the circulation. It must be observed that the force of the blood on the sides of the sac diminishes in an inverse ratio to the increase of its sides,* which therefore are longer in dilating than might be imagined; but after proceeding to a certain length the adventitious coat, gives way, and the blood is effused into the surrounding cellular membrane, producing distention; and when the artery is a considerable one, there is an obstruction to the blood's motion in the collateral branches, producing mortification. When the artery opens externally, it is always on that side where the artery gives way most. The ultimate effect of such events will vary somewhat, according to the situation of the aneurism ; thus, if it be of the carotid artery the effusion on its bursting will soon occasion suffocation, &c. When an aneurism is in an artery whose dilatation brings it to the skin, the coagulum comes first, and obstructs the circulation in the skin: the skin inflames and mortifies, forming a black slough, which dries and adheres to the coagulum. As the slough separates, there is an oozing of blood at the edges, which becomes more and more, till at last in a large artery, as the aorta, the plug may be wholly pushed off, and the patient die instantly. If in a smaller artery death will be more gradual.

* [The author does not seem to have been acquainted with the hydrostatical law'^of equal pressure contained in the following words; viz., that when a quantity of fluid contained in a vessel is submitted to compression, the whole mass of the fluid and the whole surface of the vessel, however large, is similarly and equally affected : consequently the enlargement of the sac can make no difference as to the quantity of pressure which any given portion of that sac has to sustain. See Arnott's Physics, Vol. I., p. 242, 4th edit.] 312 HUNTER'S PRINCIPLES OF SURGERY. Of the Method of Treatment, with the Opinions of Messrs. Bromfield and Pott.—This disease, if not attended to, is as dangerous as any that can affect the human body, because it is such as must always, even in the smallest arteries, kill; for as it arises from disease, the artery has neither the disposition nor power to relieve itself. Death must therefore be the consequence, either from the bleeding, or the consequences arising in the parts into which the blood is effused. Nor does it appear that the artery, either above or below the swelling, where it is sound, takes the alarm, or is stimulated to action; so that there is no resource, and death is the consequence. However, this disease is often capable of removal. When increased to a large size it is a very difficult operation; but I should wish it to be performed when the tumour is small. Messrs. Bromfield and Pott having written on this operation, and their opinions being different from mine, it is necessary that I should defend those opinions which I have adopted, and which I have spread abroad. Mr. Bromfield objects to every operation, either amputation, or for the aneurism ; this would be just if what he asserts was true, viz., that the whole of the arterial system is in general diseased, which however is certainly not the case. He says, too, " that the injecting of parts in dead bodies having shown that in particular subjects the branches sent off have now and then formed anastomoses with other branches given off lower down, has led to very extravagant notions of the smaller branches being always able to carry on the circulation; and an extravagant proposition has been suggested by some people to tie up the principal trunk of an artery in the extremities. I once saw an attempt of this kind in a true aneurism of the ham, in which 1 shall only remark that the patient died; and I do believe that the embarrassments which occurred, as well as the event of the operation, will deter the gentleman" (meaning me) " who performed it from making a second attempt in a similar case." Now, unfortunately either for Mr. Bromfield or myself, this is the very case from which I have formed favourable ideas of the success of future operations of a similar nature. Mr. Pott, after describing the disease in its last and most violent stage, just preceding dissolution, and when it has done all the mischief it can do without destroying the life of the patient, says, " If a man was to be asked how the disease was to be treated, he would answer, from theory, that the artery should be tied above and below the tumour, and the coagulated blood be evacuated; but that the artery is generally diseased some way above the dilatation, especially the popliteal." He also observes, " that the want of collateral branches of sufficient size to carry on the circulation is another powerful impediment to the operation." When the aneurism has arrived at the stage which Mr. Pott describes, perhaps the only thing is to amputate above the dilated part of the artery: but Mr. Pott should have considered, that before these threatening symptoms there is a stage when all the surround- OF HEMORRHAGES AND ANEURISM. 313 ing parts are sound. If this be true, would any man allow a disease in a part to go on till the surrounding parts are diseased and past cure ? The events of all diseases are of two kinds : first, where the termination is certain; 2d, where it is dubious. The aneurism is of the first kind ; its event is certain. Now I do aver, then, that there is a stage of the disease in which the operation is safe. I do not, certainly, know how to judge of this state from the external appearance, but from what I have seen of aneurisms, I believe it will allow of considerable latitude. My opinion is, that the operation should be performed, 1st, when the disease has done no mischief to the surrounding parts; 2d, where it is distinct and circumscribed, not connected with parts which may not be curable when exposed, as bones; 3dly, when there is a distinct pulsation. How early the operation may be performed I do not certainly know, but my opinion is that it may be done as soon as the aneurism is known to exist. By some it has been recommended to permit the disease to exist some time first, because, say they, as the circulation becomes obstructed, a freer communication will take place between the branches above and below; but this would not be until the obstruction had subsisted some time, and I would not wait for this, for fear of the consequences described by Mr. Pott. When the disease is in an advanced stage, I agree with Mr. Pott in thinking amputation necessary and preferable, but not under the circumstances above mentioned. The earlier, therefore, the operation for the aneurism is performed the better, not waiting with the expectation that an increased size of the aneurism will produce an increased size of the collateral branches. That the popliteal artery, according to Mr. Pott, is oftener diseased above the aneurism than other arteries, I cannot well determine, but can see no reason why it should be so. If the artery, however, cannot be tied above the aneurism in the operation, where can it be tied if the limb be amputated ? Why not tie it up higher in the sound parts, where it is tied in amputation, and preserve the limb ? The circumstances to be regarded chiefly turn upon the collateral branches being sufficient to carry on the circulation. The only arteries which admit of this question are the popliteal, femoral, and brachial; the other arteries either having a very free anastomosis, or being out of the way of any operation. In this account it may be supposed that I carry my notions too far ; but it is to be understood that I only give my own feelings upon this subject, and I go no further in theory than I would perform in practice, if patients, being acquainted with the consequences of the disease, would submit to, or rather desire, the operation; nor do I go further than I now think I would have performed on myself were I in the same situation. Not that I would have it supposed that I would recommend this at large : I would have no one perform an operation that he is not clear about the propriety of himself, espe- 27 314 HUNTER'S PRINCIPLES OF SURGERY.

cially when it requires more anatomical skill than falls to the share of most practitioners. Of those Arteries which admit the Operation.—These are, first, the carotids above the sternum; 2d, any of the branches of the external carotids; 3d, the subclavian (after having passed the scaleni muscles), and of course its trunk and branches down the arm ; 4th, the crural, immediately after having passed Poupart's ligament, and given off the large muscular artery. How far it would admit of an operation above the giving off of that artery I do not know, but I have seen one instance of that branch and the vessel itself being obliterated by an aneurism, and yet the limb was supplied with blood. Some of the branches of some of these arteries which I have mentioned will be very difficult of access: therefore, if not in parts that will admit of amputation, the patient will be likely to die. It will be very difficult to take up the anterior and posterior tibial and interosseous arteries, and it will be often necessary to amputate, from the difficulty attending taking them up, besides that the bone will often be diseased before we discover the disease, and this will make amputation necessary. If an aneurism should take place in the axilla, I should doubt of the propriety of taking up the artery above the clavicle, because I should doubt of its being sound. The same with the femoral artery, where it passes from under Poupart's ligament; unless the aneurism was lower down, and I might expect to find the artery sound. In dissecting tumours from the neck I have frequently laid bare the carotid artery; now, if by any accident during the operation the artery had been wounded, I should certainly have taken it up with a ligature ; or if the tumour had been so engaged with the artery that I could not disengage it, I should have tied it above and below the tumour, with every hope of success. The operation will be easiest, both to surgeon and patient, while the disease is in its infancy. Although I would perform the operation on all the arteries I have mentioned, and if I laboured under them myself would have them performed on me, yet I would wish every person to judge for himself, and not attempt an operation if he is fearful. General Observations on the Operation*—In performing this

* [It will be observed that the operation Hunter here describes is not the one which goes by his name, but that which was usually practised previously to the general adoption of the Hunterian operation. The first case in which Mr. H. operated according to the latter method occurred in December, 1785, rather more than a twelvemonth before the delivery of this lecture ; and he did not as yet feel sufficiently sure of its superiority to the generally received method to recommend it strongly to his pupils for their adoption. I gladly avail myself of this opportunity of referring to Mr. Guthrie's able and elaborate exposition of this department of surgery, in his work " On the Diseases and Injuries of Arteries,'''' in which the extent and accuracy of Mr. Hunter's labours are set forth with great judgment. The Hunterian operation for aneurism OF HEMORRHAGES AND ANEURISM. 315 operation the first attention should be paid to preventing the flowing of blood during its performance, which alone leads to two methods of performing it: 1st, where the tourniquet can be applied; 2dly, where it cannot. Where the tourniquet can be applied, this should be first done. In the next place make a longitudinal incision in the course of the tumour, of greater extent than the tumour ; cut gradually into this, scoop out the coagulated blood, and sponge the inside of the sac ; we should then slit up the sac, to discover the openings of the arteries into it. The inferior orifice will be most readily discovered, as it will throw out some little blood of a venous appearance. To discover the superior orifice the tourniquet must be slackened ; the artery then should be tied, at least an inch from the sac, at the superior part; but it is not necessary to observe this rule with the inferior part. When a tourniquet cannot be applied between the heart and aneurism, as in the carotids, an incision is to be made through the integuments ; the sac is to be laid bare, but not opened ; the artery is to be searched for, and tied above and below on the sound part. The sac is then to be opened, and the coagulum scooped out; and after being cleansed and spunged, the sac may be left to slough, and the wound dressed as other fresh wounds. The blood which comes from the lower orifice has become dark by stagnation, or slow motion: hence also the dark colour of blood when an artery is wounded below, while the tourniquet is applied, the blood not being venous, as some have thought, but arterial, which has taken a retrograde course. I believe we should not be anxious about the collateral branches; I have lost several advantages from this mistaken delicacy. I believe the circulation will always go on after the femoral artery is secured by ligature. Cases of Aneurisms.—1st, a young man had for two years a pain in the calf of his leg, similar to cramp; at length he received a blow in the ham, and a swelling, with pulsation, appeared soon after. I gave it as my opinion that the operation should be performed, and if it did not succeed, then to amputate. The operation was performed, and the patient apparently was going on well, till the fifth day, when the ligature giving way, the artery burst above, either from its being tied too tight or too loose. I was now obliged

was not the result of fortuitous discovery, but of accurate and minute knowledge, derived from a laborious investigation of the morbid anatomy of the arteries, and of just reasoning upon the data which he thence derived. The preparations and drawings relating to this subject contained in the museum of the Royal College of Surgeons, convincingly show that Mr. Hunter anticipated the greater number of modern discoveries, at the same time that they evince the indefatigable zeal with which he pursued his researches on professional subjects. By referring to the valuable work above mentioned, I shall save myself and the reader a great deal of trouble in these notes ; and I am very happy in having the opportunity of expressing my acknowledgments to the worthy author. I also beg leave to refer the reader to Sir Everard Home's paper on the same subject, and to the remarks in "the Life."] 316 HUNTER'S PRINCIPLES OF SURGERY. to dilate the wound still higher, and take up the artery higher up; but, apparently from the loss of blood before the tourniquet could be applied, the patient died a day or two after. The leg and thigh were both found to be putrid and emphysematous, and that was the case even above the aneurism. When I saw this man dying from the loss of blood, it struck me as a proper case for transfusion, and if I had been in his situation I would have had the blood of a sheep or hog transfused into my vessels. I do not know exactly how to account for the failure of this operation, whether from the unsoundness of the vessel, or the tightness or the smallness of the ligature; but from the appearance of the limb before the bursting of the artery, and the injection of the vessels after death, all seemed favourable for the operation. The artery also was sound above the part where the first ligature was applied. From these considerations, I should certainly be encouraged to perform the operation again, though this was the case which led Mr. Bromfield to condemn the operation. The second was a case of femoral aneurism in the middle of the thigh, in which the operation was performed by Mr. Bromfield, jun., in presence of Mr. B., sen., after his publication. The tumour was oblong, and extended five or six inches in length, and the operation was performed in a short time, and with success. In the third, where the operation was performed by Mr. Martin for the popliteal aneurism, the patient soon got well, and was able to dance. The fourth was an aneurism in the gluteus muscle. In cases where the arteries in several parts had the disposition to this disease, or, in other words, where many aneurisms were formed, the operation would not be advisable. In December 1785, I performed the operation at St. George's Hospital, in a case of popliteal aneurism, in a manner different from that ordinarily practised, and with success. The particulars of this case are given in the London Medical Journal. I would only observe, that in future I would advise only tying the artery in one part, and not to endeavour to unite the wound by the first intention. In that case four ligatures were applied upon the artery. OF SPECIFIC DISEASES, ETC. 317 CHAPTER XX.

OF specific diseases, tumours, hydatids, ETC.

Of Ulcers and the causes which retard their cure.—Abscesses___Specific diseases.—Irritable and indolent dispositions.—Hypertrophy of parts from chronic inflammation.—Varicose veins.—Corns,—Chilblains.—Of the unnatural growth of parts.—Preternatural accumulations of fat.—Elephantiasis.— Observations on the cure of indolent dispositions.—Tumours.—Encysted tumours.—Tubercles.—Solid tumours.—Warts.—Polypi.—Tumours in the cellular membrane.—The removal of tumours.—Tumours of bones ;—their varieties.—Encysted tumours.—Hydatids.—Cuticular tumours.—Of the inflammation of adventitious substances.—Fistulas.—Fistula lachrymalis.__ Fistulae of the buccal glands.—Fistula? of Cowper's glands.—Fistula of the parotid gland.—Fistula in ano—Fistula in perineo.—Cure of Fistulae.—Of the treatment of contracted joints___Of tetanus.

I come now to speak of what I call specific diseases, but before doing so I shall notice the causes which retard the cure of ulcers in sound parts. These often arise from circumstances not at all connected with the soundness of the parts, as their situation, depth, nearness to tendons, or vicinity with respect to the heart. The situation may make it tedious, though the parts are otherwise strongly disposed to heal, which is often the case in deep-seated abscesses; 'the nature of the parts may retard the cure, as when abscesses are situated in parts endued with slow or weak living powers, as bones, ligaments, or tendons. In such cases the matter goes a considerable way before it reaches the skin, while the superficial parts are more disposed to heal than the originally diseased deep-seated parts, so that abscesses soon become fistulous. The cure depends on removing the obstacle of depth by free opening, exposing, as much as the nature of the part will admit of, the bottom of the wound, and preventing the healing up of the superficial parts; but this must not be done unless or until the deep-seated parts are as much disposed to heal as the superficial, so far as respects their natural power, as in cases of exfoliation. Many are slower in healing from the nature of the parts themselves, as bones; but the treatment in such indolent- dispositions is very different from that of acquired indolence; for in these there is a disposition to act, whilst in indolence, which is natural, this is wanting. Hence it is dangerous to rouse these parts much, and accordingly we find that the mildest treatment is generally the best, often employing sedatives to lessen the consciousness of danger, as opium, which has often the best effect on parts naturally slow or indolent in disposition, as tendons. Many sores which go on well at first take on afterwards a 27* 318 HUNTER'S PRINCIPLES OF SURGERY.

quality contrary to health. All kinds of sores are subject to this change ; but in specific and poisonous ones, the poison must first be destroyed before a good disposition can take place. The causes of this change of disposition are many, but few of them are visible. The most visible is their situation in the body, as in the legs, which are far removed from the heart, and where the healing is prevented by much walking. The slowness often arises from exercise and intemperance, which are first to be attended to in the cure. A horizontal posture, with temperance, should be the first thing advised in sore legs in general, as removing the accidental impediments to healing. When sores do not heal, after having removed the above causes, some other cause must be remaining, as either an indolent or irritable disposition, or some specific quality, which is frequently to be discovered by experiment. If irritable, sedatives are to be used; if indolent stimulants ; but if it is not known which of the two exists, first try one, and then the other; if neither of these is effectual, a variety must be tried till you find that which agrees best. Sometimes one of these does good for some time and then loses its efficacy, the sores becoming stationary, when we must change the application. When sores are indolent in healing, there is a surrounding thickening, but this is seldom the case when healthy granulations arise; in such compression is proper; and if walking cannot be avoided, then light bandages, and sometimes a thin plate of lead, which is also often useful when the granulations are loose and there is a disposition to thickening. But these sores are very apt to return, which points out some particular remote cause, which I will presently describe. The sores of poor people are often in a bad condition from bad living, much exercise, or cold, and are often mended by rest, a horizontal position, fresh provisions, and warmth in hospitals, and the change is generally very speedy. If they do not soon improve I always suspect that something more is operating, as irritability or indolence, when I try experimentally different remedies till I pitch on one that is serviceable. The surface of the sore will easily discover if there is disease beneath, as of the bones or periosteum. If the granulations are broader than the disease underneath, the granulations over the diseased part are unhealthy, whilst those not so are healthy, and heal so that the sore becomes smaller and smaller by the gradual contraction of the granulations. Sores are often forced, as it were, to cicatrize, but the cuticle is not good, and the part removes it, and removes it again and again, till sometimes at last it becomes a good one ; at other times the cuticle becomes very thick, and irritating the cutis underneath, which is very tender, it is then thrown off like a scab, and leaves the skin underneath ulcerated. These cases must be treated as they were before they were cicatrized ; that is, they must be kept moist, and any cuticle which is unnecessary and thick must be scraped off. The medicines that first healed the sore, combined OF SPECIFIC DISEASES, ETC. 319 with water, should be applied to the sore ; as, when tar agrees, tarwater should be applied. Abscesses.—In all abscesses we should consider, in the first place, whether their seat is on or in the part at which they appear, for often they are abscesses of parts that are distant from that in which they appear. Thus, the external appearance of lumbar abscess is in the thigh, the loins, or between the ilium and sacrum. Abscesses of the liver also make their appearance externally; likewise spurious empyema and abscesses of the kidneys, which last often resemble lumbar abscesses, although their seat has been ascertained by the extraction of a urinary calculus. All these generally pass through and between some bands, as tendons, ligaments, or bones, and their first passage is small; but the abscess, getting into the cellular membrane, spreads, and gives the appearance of a large abscess of that part. None of these, however, penetrate so far as the lumbar abscess, owing to the position of the body, and the disposition of the inflammation having no tendency to set bounds to the spread of the matter. Treatment.—Little can be done for these cases ; they should be opened slightly or not at all. In the lumbar abscess opening is often productive of hectic fever, much sooner than if left to itself, and consequently death takes place much sooner. But when internal abscesses, whether pointing at a distance from the seat of disease or not, are likely to heal, as those of the liver, they should be opened as freely as possible, in order to know the extent of the disease. If they cannot be traced to the bottom, injections may be, used, as they are apt to become indolent. I have used stimulating solutions of caustic, infusion of myrrh, lime-water, and injections of decoction of bark.

I am now to treat of dispositions and actions which are not productive of restorative actions; those which we have hitherto treated of, where a salutary disposition is put on, in consequence of violence done to a part, I do not call disease. This is the most complicated part of surgery, as it requires a knowledge of sores and of every local action that can be in a part: it is the physiology of surgery, as a knowledge of the constitution is of medicine. The diseased sores alluded to will admit of being divided into local and local constitutional; but none are entirely constitutional. The first includes many diseases, as cancer, chancre, mortifications, and many others, which have simply some specific quality. The second, all the poisons and some mortifications. All uncommon actions, commonly called diseases, are divided into common and specific. The common I have treated of. The irritable and indolent may be thought improper to be placed among the following, which are the specific, because either of them may attend all specific diseases; but almost all uncommon actions are in some 320 HUNTER'S PRINCIPLES OF SURGERY. measure specific, all arising from a specific tendency, or susceptibility, brought into action by some leading cause, and therefore not taking on the restorative process as they ought to do. Every specific disease must have some peculiar action distinct from another. A true specific disease is that which has only one peculiar action. Some have many causes, as gout, yet have only one specific mode of action; others, as the morbid poisons, have only one specific cause. The first is divided into two ; regular and irregular. The regular are truly specific, as agues; of the irregular there are many which show disturbed modes of action, as inflammation in scrofulous habits; but these always are very imperfect, from the specific action hindering them from going on properly. These are the opposite to the salutary dispositions for restoration. Unsound dispositions may be divided into two classes; such as have too much action, and such as have too little action; or better perhaps, into irritable and indolent. The remote causes are many, but the immediate cause may be the same in both: few of the remote causes are known. Irritable and indolent might be classed amongst the common diseases, and not with the specific, as every specific disease may be accompanied with them, and all specific diseases are generally attended with one of them ; but some specific diseases are more irritable or indolent than others, and are also different in different constitutions. Of the Irritable Disposition.—Irritability is that disposition which Cannot remain at rest under an injury either in a part or the whole, nor can it set about a restorative action. This depends on some peculiarity both of the nerves and living principle, for there is often much sensibility as well as irritability in a part; or, on the contrary, it may be confined to one only. The one wrould show that there is an affinity or connexion between these two principles; the other, that this is not absolutely necessary. Irritability is of various kinds, but generally may be called passive; as even in the most irritable constitution there must be some other disease or some violence to bring this disposition into action. Thus, convulsions, are induced by tickling the skin. Many constitutions are thrown into violent actions from injuries, producing irritable inflammation. But all inflammations are not to be called irritable; those which are exactly sufficient for restoration cannot with propriety be called irritable. Irritability is most commonly constitutional, but not evidently so altogether, as one part is often irritable, while other parts are not: for example, a lady had a vesication on her shoulder, which all throughout its action gave amazing pain; yet at the same time she had one in the arm which gave very little inconvenience. And we find disease producing irritability in parts which were not irritable before; therefore it cannot be said to be constitutional altogether. Irritable inflammation most frequently arises from injuries done to an irritable habit. A local disease may produce irritability in a OF SPECIFIC DISEASES, ETC. 321 part, whilst the constitution is not irritable at all; it is then entirely local. But the constitution may be rendered irritable from a local cause, as in bubo. An irritable disposition is generally known by a disposition to inflammation, and that inflammation not terminating in any crisis. It would appear to be a mixture of the suppurative and erysipelatous, at least the erysipelatous seems to attack irritable constitutions most frequently; but probably the erysipelatous attacks when there is weakness, and erysipelatous goes off as in other habits. The effusion and extravasation in irritable inflammation is more watery, so that the swelling is rather cedematous and more diffused; the continued sympathy is very strong, so that it spreads often to a very great extent, and sometimes becomes universal. In many of the irritable inflammations of the skin, excoriation takes place, and the water exudes like a blister. When it is local it is very circumscribed, terminating all at once; in many cases it cannot be distinguished from common inflammation terminating soon, but here the irritability is slight. These often terminate in the indolent, as those arising from cold. Of the Cure by Resolution.—To cure irritability is extremely difficult, as lessening sensibility is more difficult than exciting parts when indolent. Whilst the parts are only inflamed, we should first avoid every thing which would irritate or hasten suppuration. A cataplasm of bread and milk is the most simple resolutive application, and the best till we know how further to proceed. But when from any accident there is too much irritability, something to lessen susceptibility should be used, as opium in the poultice, a fomentation of poppy-heads, or the preparations of lead. However, I think preparations of lead may do harm, as they lessen the restorative power as well as the irritability. If suppuration takes place, it should be suffered to go on to the true suppuration. Cutting is very disagreeable to these irritable parts, for the irritability still remains, and they will not heal kindly. Caustics are much better adapted for opening abscesses in such constitutions, and should always be preferred, and more especially if opium is joined to them, as either with or without opium they irritate much less than cutting. The matter is generally of a consistence little more viscid than serum. There is often coagulable lymph on the sore, in which case there is little discharge of pus, which is also often the case in the indolent. The milder the after-dressings are the better; none is preferable to the opium poultice, as they are apt to ulcerate and spread, which opium prevents better than any other dressing. When they begin to have a healing disposition, a mild cerate is preferable to dry lint. Bark internally, as lessening irritability and giving strength to the system, is of considerable service, together with the exhibition of opium ; but in some we find a treatment directly opposite necessary, the mildest dressings giving the greatest pain, whilst warm dressings, as oleum terebinthinae, give agreeable ease, although at first they give great pain in such sores. There is some peculiarity in 322 HUNTER'S PRINCIPLES OF SURGERY. the part which is removed by these stimulants; but unfortunately all these fail at other times, and we do not possess a sufficient number for the variety of constitutions we meet with. Of Indolent Dispositions and Actions.—Local diseases attended with indolence produce generally the following effects, viz., an increase of the parts diseased, which is of three kinds: 1st, increase of growth of the natural parts; 2d, a thickening of the diseased parts: 3dly, an entirely new-formed substance. The first has no variety; the second is occasioned by adventitious matter extravasated and effused into the cells, which I call interstitial increase, which will produce two different effects: either general swelling, which I call the diffused interstitial; or circumscribed increase, which I call the circumscribed interstitial. But the last has two causes, and is of two kinds; therefore the first owes its figure to the part being circumscribed, the other is from the nature of the disease. The third is always circumscribed, which I call the circumscribed adventitious. They are often spontaneous in their origin. Indolent dispositions may be either with or without inflammation, and also suppuration; they arise from either a disposition of the constitution or part. This is more rare than the irritable, and is seldom carried so far. Few constitutions are so quiet as not to call forth their powers when a part has received any injury. But specific affections may sometimes prevent them, and then the common powers have no effect; for in lues and scrofula thickened sores are very frequent. There may be indolence without any known specific cause; yet I suspect that there must be something specific concealed, which arises from peculiar constitutions in different complaints, as when tumours that are indolent are formed in glands. All constitutions, however indolent, are susceptible of inflammation, and very few diseased parts are exempt from it; yet sometimes indolent sores are not inflamed by the common causes of inflammation, as exposure; sometimes, in the irritable, sloughs are formed, which is a cure by the disease itself. After indolent parts are once inflamed, they are very apt to become indolent again, when the inflammation is removed. When indolence is in a diseased part it cannot be totally constitutional, but sometimes local, as in cancer and scrofula. When this indolence takes place in a part, the cause often steals on gradually, so that the part is not roused by it. Indolence is natural to tendons, ligaments, and bone, and when all these causes cooperate, the disease is worse; but indolence may take place in other parts, from some visible cause, as in muscles, and skin producing thickening. Many thickenings are owing to specific causes, as the induration of cancer, venereal diseased glands, sometimes affections of gout and rheumatism, and bone is subject to the same disease as in exostosis. Thickenings of parts are either from visible or invisible causes ; the first arise from some external inflammation; the second from OF SPECIFIC DISEASES, ETC. 323 some diseased action in the part. The remote cause may be predisposition, climate, or way of life. Local indolent diseases are generally confined, yet they sometimes spread; but here the cause must be more diffused. They spread but little, because indolence is but a small cause of sympathy; the sympathy is more continued when the sympathizer is of the same indolent disposition as the diseased part. Indolence in local diseases is attended with an increase of the part, sometimes similar to that produced by adhesive inflammation: this effect attends many unnatural actions of parts as well as inflammation. The parts swell more in this disposition than in the others ; for in this there is neither any disposition to suppuration or resolution, and therefore there is an increase in the thickening disposition. The division of this thickening is of three kinds, as before observed. The first is most visible in the adipose membrane; the second, as before; the third, adventitious, and which forms a tumour. The immediate causes are: 1st, a preternatural increase of the part itself: 2dly, interstitial increase ; 3dly, the formation of an entirely new part. The first consists in an increase in the figure of a part, as of a gland, a cell, any whole limb, or other whole part; the second is often circumscribed in cellular membrane, appearing to be newly formed ; but it is not so, but interstitial, as scirrhus in a glandular or cellular part, which becomes loaded with cancerous coagulable lymph formed by inflammation: the third is an original circumscribed swelling, arising in common cellular membrane, skin, bones, &c, and which should be called true tumour. In some of these diseased parts another disposition or mode of action, viz. ossification, arises; whether from a peculiar disposition arising from this disposition, or to increase the strength of the part, I am uncertain. The first is most probable, as strength is unnecessary where it is generally formed, viz. on the edges, &c. I shall lay it down as an axiom that all thickened parts are to be accounted new-formed parts, although they may be in original parts. The idea of their being all new parts shows why they should be disposed to form calcareous earth. Thickening, which is generally the first symptom of indolent complaints, often gives little or no pain; so that the sensibility is often not observed till some time after. The thickening gives so little pain as hardly to be communicated to the sensorium : but the heavy dull kind of pain afterwards often becomes very disagreeable, producing sickness, which is more peculiar to some parts than others. The colour is of no particular kind, which shows a languor of the blood in them. The hardness is sometimes so great as to become cartilaginous. The causes of this thickening are with difficulty assigned. In common inflammations there is increased action, and this is probably the case in indolent inflammation: but this increased action is of a peculiar kind, which may be called indolent inflammation, which is a peculiar mode of inflammation. The immediate causes are 324 HUNTER'S PRINCIPLES OF SURGERY. various ; but what the final intention is in most cases is very obvious. In common inflammation it is to form adhesions and limit the disease, but in the indolent it is to give strength. The visible causes of indolent disposition are various. 1st, The thickening may depend on a diseased part being accustomed to an irritation, till this irritation, losing its power, leaves the part in an indolent state and incapable of recovery. Probably all may be first ranked under the irritable. 2dly, From effects being produced by a disease not indolent in itself, but violent at first, as the gout. 3dly, From a slow alteration in structure taking place, in consequence of gentle irritation, as gentle pressure, which will take place in every part. 4thly, a long application of cold, which produces weakness. 5thly, Peculiarities in climate: as bronchocele in Derbyshire, and swelled legs in Barbadoes. These, and especially the four first, have no connexion with the constitution, yet may be assisted by a constitutional predisposition. They are seldom very diffusive, from their confined sympathy. The first of the first division are most frequent in the lower extremities, these parts being most frequently interrupted in their salutary actions. The second, arising from a disease in itself violent, as the gout, are apt to be very indolent. The third cause is mechanical and very extensive, even universal, and seems to be the consequence of a stimulus, as if increase of strength was wanted, as in the tunica vaginalis, from the increased quantity of water in hydrocele, cysts of hydatids, &c. Veins from this cause become varicose, and the cuticle is often thickened by this in working people ; but this is frequently carried too far, and produces corns, or it may produce ulceration if the pressure exists in a still greater degree. Varicose Veins appear to arise from pressure. A long column of blood presses along the inside of the veins of the lower extremities, and the veins being weak are stimulated, which increases their thickness and strength to resist this distention; sometimes they are so much thickened as to obliterate the whole cavity. The smaller veins are more or less affected, probably in the same manner as the large ones are in the legs, and hence the whole leg is indolent: they often suppurate, when it is almost impossible to heal them. This disease is in general too extensive for extirpation, although when it can be done this practice is very proper. Corns.—The cuticle admits of being thickened from pressure in all parts of the body: hence we find that on the soles of the feet of those who walk much the cuticle becomes very thick; also on the hands of labouring men. We find this wherever there is pressure, as on the elbow, upper part of the little toe, ball of the great toe, &c. The immediate and first cause of this thickening would appear to be the stimulus of necessity given to the cutis by this pressure, the effect of which is an increase of the cuticle to defend the cutis underneath. Not only the cuticle thickens, but the parts underneath, and a sacculus is often formed at the root of the great toe, between the cutis and ligaments of the joints, arising from the same cause, OF SPECIFIC DISEASES, ETC. 325 to guard the ligaments below. Sometimes, when the pressure is uncommonly great, inflammation takes place in this part, especially if there are corns, the sacculus suppurates and opens externally, and this forms what I believe is called a bunion. The sacculus then closes again, and leaves the parts much as they were before. The cuticle is not only thickened from pressure for salutary purposes, but it is also carried to disease. A corn is a thickened cuticle arising from external pressure, which is preternatural and continued. Uncommon or preternatural pressure on the surface must always affect the cutis more or less, producing a disposition in it to guard itself; but pressure is capable of producing another effect, which is according to the amount of pressure: when applied in a moderate degree, it gives a disposition to the cutis to continue the growth of the cuticle, forming layer upon layer. By this continuation of growth the cuticle becomes thicker; but if the pressure is too violent, then a diseased increase of the cuticle takes place, commonly in a very small portion of the part pressed, often in a point. This thickened part being pressed from without commonly sinks its own thickness into the cutis, which is the cause of the pain and troublesome symptoms. The cuticle being formed in layers peels off in layers, and if inflammation attacks the cutis underneath, this takes place : and hence the term ' onion,' which has been applied to these corns. There is often a sort of joint formed by a sacculus mucosus under the cutis allowing of motion in the corn: if this inflames and suppurates, a cure is often effected. When corns are of long standing and run pretty deep, they generally produce a degree of indolence in the healthy actions of the parts pressed on, which makes the cure tedious. The cure of corns is of three kinds, viz. natural, palliative, and radical. The first is by removing the primary cause, or pressure, which is done by leaving off shoes, or by introducing a soft substance, as plaster, between the corn and shoe. Two plasters are necessary, one with a hole opposite the corn, and another to be applied over this; and these should be continued as long as the cause is continued. Leaving off the pressure is the best mode, and then the effects are easily removed. The palliative consists in removing as much as possible the external surface, which relieves the pressure. This is done by holding the corn half an hour in warm water, when it swells, and then paring off as much as possible of it. It is difficult to remove the whole without injuring the surrounding cutis, which is often of bad consequence in old people, where fatal inflammation and mortification have been caused by it. The radical cure consists in removing the whole corn or thickened cutis. The cuticle may be raised here, as it is in every other part, by blisters: but its thickness prevents this effect taking place so early. Warm stimulating plasters will in general be sufficient. The causes of corns when carried too far often produce inflammation and suppuration, and whichever way the suppuration is pro- 28 326 HUNTER'S PRINCIPLES OF SURGERY. duced, it is liable, if not attended to, to become very tedious: for the skin having a greater disposition to heal than the parts underneath, produces a fistula ; so that such sores should be dressed to the bottom, and if they are indolent at the bottom should be stimulated by appropriate dressings. Indolence from Cold.—Cold is a powerful obstructor of the natural animal powers, whilst at the same it is exciting action, producing irritable inflammation and death. It is a true cause of mortification. Indolent swellings from cold arise from two different modes of action: 1st, when so gradually applied as not to excite irritable inflammation, but a gradual sluggishness ; 2d, when it produces irritable inflammation from the parts being weakened. Cold does not immediately obstruct the natural actions of the whole or part, but excites the whole or part to another action, viz. the production of heat. The extremities, from their great distance from the seat of the living power, and from being smaller, are most liable to this. Thus these parts become first irritable and then inflamed; but it is an increased disposition to act, with lessened powers. Hente the effects of cold are greater or less, according to the constitution. The weakly, the fair, and the delicate have the least power of generating heat. Chilblains are the common effects of these causes, and from the foregoing effects of cold we are led to a rational cure; first, to remove the cause, then to apply warmth, or rather to keep the parts temperate. Chilblains commonly get w7ell in summer. The cure, perhaps, should be divided according to the two stages of the disease, viz. the irritable and indolent; but how far the treatment should correspond in this way I cannot say. The}7 have bee» cured when they looked purple and livid by gentle stimulants, as oleum terebinthinae, or camphorated spirits of wine. Such applications bring on the florid red of inflammation, which generally terminates well, for they seem to counteract the stimulus or irritation of cold. Steeping the parts in warm vinegar has done much good ; when they ulcerate, the same exciting mode seems best. But they are sometimes so irritable as to require quieting; for which purpose a poultice or decoction of poppyheads is equal to anything. When the itching begins, rubbing the feet over with powdered chalk will be effectual to prevent it: the rubbing is useful, and the chalk keeps the feet warm by being a bad conductor of heat. The invisible causes of indolent dispositions are also various. The 1st of the spontaneous is a diseased increase of growth ; 2d, interstitial swelling; 3d, new formed substance. This division, according to the mode of increase, is into three kinds, viz. increase of natural parts, the interstitial, and the tumour. All these are liable to happen in every part of the body. These increases are either known by the sight or by the feel. Of the unnatural Growth of Parts.—These often form what mav be called a species of monstrosity of parts, either diffused or circumscribed. They are. generally situated in the cellular membrane, OF SPECIFIC DISEASES, ETC. 327 and feel doughy and soft, and are usually superficial, extending to the skin till it hangs as if by its own weight, sometimes having a broad base, but often hanging by a small neck: they appear to be in the cellular membrane what exostosis is in bone. These parts are less ductile than the natural parts. I have seen the double chin become one of these; I have seen them on the belly. Perhaps they produce absorption in the parts on which they press; for the bones underneath have been sometimes found deficient. Preternatural accumulations of fat take place in the same manner ; not depending on a deposit of interstitial substance, nor being adventitious, but a preternatural growth ; and are common to every part of the body, not excepting the internal parts. People have died of fat on the pericardium, and sometimes it is found in the bellies of cattle, as sheep. In the human subject these accumulations acquire an immense size, being composed of very solid fat, and in some degree moveable, being in separate parts, or lobulated, when between the skin and muscles. They may in general be distinguished by the former being of a regular uniform softness, whilst the latter appeared to be composed of solid pieces of fat, having a surface irregular to the feel. The interstitial or diffused thickening of a part arises from the interstitial deposition of matter in the cells of the part, and is of three kinds. Elephantiasis.—The first, or diffused, is very slow in increase, forming gradually. A whole leg will become stiff and feel tight by a loaded cellular membrane. It is most frequent in the legs, and almost peculiar to some countries and to some peculiar constitutions. A similar increase occurs in the thyroid gland : but this is of the second kind. The diffused is very common in the legs of Barbadoes' people; I have also seen it in this country, but very rarely. The legs of young people I have seen so swelled as to be all of a size. It arises from an extravasation of coagulable lymph equally diffused ; the parts become firm and similar to dropsy, only there is no pitting: it may be a kind of dropsy, for dropsical swellings often degenerate into this kind of swelling; yet the cause of the two may be very dissimilar: it is most frequent in young people. From its being so diffused and general, and in the legs, and most at the lower parts, I should think one of its immediate causes was a depending situation, with a weakened action of the system in general, as a simple bandage to support these parts often prevents it. [A preparation was shown in which a thickening of the leg put on the appearance of brawn.] There is no fixed cure. In the case I saw I recommended mercurial ointment to be rubbed into the parts, and a slight bandage. The ointment was omitted ; but the patient got perfectly well in a few months. If these had failed, I should have sent him to bathe in the sea. Pressure hinders the extravasation of more fluid, and we see that tight boots make the legs thinner. The second kind is an original disease, though it may be attended with pain and inflammation. It is not circumscribed, though con- 328 HUNTER'S PRINCIPLES OF SURGERY. fined to a spot, but gradually lost in the surrounding parts. It spreads in proportion to the power of continued sympathy. A node is similar in appearance to what this is of the soft parts, and perhaps is of the same kind. The pain of indolent swellings is very little or none at first, which is owing to the slow increase of the part not arousing the sensibility; but afterwards they have a heavy dull pain, producing sickness. This is often from the size, as well as from the tumour itself pressing on some other parts; for sometimes there is more pain in the surrounding parts than in the tumour itself. I may also observe that they seldom or ever inflame, but continue increasing till they press on surrounding parts, and raise inflammation in these parts and not in themselves; they are then often broken down into a curdly substance, but appear not to be dead, as they do not give the stimulus of extraneous matter : though the surrounding parts become thickened, yet they cannot properly be called encysted. If it appears to be scrofulous, the cicuta, sea-bathing, sal sodae, sea-water poultices, &c, are to be tried ; but these are sometimes useless, and extirpation becomes necessary ; or sometimes cutting into them is sufficient. They sometimes suppurate, and then the sores are very difficult to heal. The third kind consists in the interstitial increase of a circumscribed part. This is it when the swelling keeps to the original part, that part being circumscribed, as lymphatic glands, and also tumours or enlargements of the liver or spleen. They seldom affect the cellular membrane till they suppurate, and often not then at first, which shows they have something specific in them; for if merely indolent the surrounding parts would sympathize with them, as is often the case in the mixed cases. Although these diseases are interstitial increases, yet they often become similar to a tumour, and are understood as such. Observations on the Cure of Indolent Dispositions in Diseases.— We must first inquire whether they are wholly constitutional, partially so, or merely local, as upon this rests our treatment. We must not be satisfied with the present symptoms, but inquire into the constitution, whether it is indolent or irritable. Such as arise from the constitution are generally more diffused, and are often in many parts: and such constitutions as produce local complaints show something wrong in them; however, the symptoms are not always satisfactory. I suspect these indolent dispositions of the constitution require a specific stimulus, having something specific in their nature. They do not spontaneously take on steps of cure, as inflammation does; and if they suppurate, they do not suppurate kindly; and a variety of things are required to assist them. The first thing to be done is to remove the cause, if practicable, which it often is not, as changing the country and situation. In all, resolution should be preferred if possible, by absorption; for suppuration will do much harm. To procure suppuration in such, a particular mode is required, for we are not to lessen the living OF SPECIFIC DISEASES, ETC. 329 powers, as in adhesive inflammation that is healthy, but to increase them. The earlier the treatment is pursued the better, before the habit has suffered, or the surrounding parts have sympathized: sometimes a constant application of mercury to the part, which produces a kind of irritation short of inflammation, is advantageous ; if this is insufficient, fumigations with cinnabar, or with plants which have essential oil in them, may prove serviceable. If these fail, we must remove the indolent disposition by exciting an action which they are incapable of taking on themselves. Salutary inflammation in surrounding parts will produce other good effects in indolent diseases, for indolence arises from a want of predisposition to healthy action; thus, blistering the parts, and giving cordials internally, are often of use; but the more violent the inflammation, the more effectually is the indolence of the part removed, if it can bear it. Many indolent swellings are content with their own natural actions, as natural parts are with theirs: but this is not so always; but they take on an inflammatory action, not salutary, but leading to a bad kind of suppuration. The means of restoring the thickened parts is healthy inflammation, which as it goes off, does not leave them in their former state, but occasions an absorption of the extravasated matter; nevertheless the part, after healing, often retains somewhat of the original disposition. This treatment will not do either in cancer or scrofula. Of the Suppuration of Indolent Parts.—Resolution cannot always be effected, and suppuration will take place, which suppuration seems to arise from defective animal powers, and not from exerted powers. The matter is glairy, and the superficial parts are so little susceptible of this that the matter is long in coming to the skin; so that stimulating medicines must be applied to bring on, if possible, good suppuration, which can seldom, however, be done. Quick ulceration is best effected by exciting and hastening the inflammation; this is necessary in sound abscesses even, but much more necessary in indolent ones. The next thing is opening them, which should not be done too early, as the matter which remains in may increase the inflammation, which is necessary to the cure. When an opening is made it should be as large as possible; and even crucial incisions are frequently necessary; in many cases scarifying the sides of the abscess is proper, to excite quick inflammation, and if there are any sinuses these should be traced to their full extent: the parts then feel a greater necessity of action. But this is not always sufficient, for after good granulations are formed, the indolent state often returns, the granulations becoming dark-coloured, and the matter thin and glairy, according to the specific nature of the indolence; this is the case often in old sores which have become habitual from bad treatment. In old indolent parts and encysted tumours the sac is often thickened, and even ossified, and the inflammation then is sometimes so violent as to threaten mortification. But these parts often become insensible to the common causes of inflammation, and when inflammation does arise it is sluggish. In such, nothing can 28* 330 HUNTER'S PRINCIPLES OF SURGERY. cure but dissecting out the parts. Many abscesses, if out of the reach of surgery, or ill-treated, run into an indolent state. Many means are necessary in treating them, but we know of few useful ones: balsams and warm dressings are commonly used; sometimes they do good, at other times they have no effect; and when they agree they lose their powers by continuance, when it becomes necessary to change them, or increase their power. These balsams should often be mixed with red precipitate. Tincture of myrrh also is often very useful in indolent sores, requiring to be applied often, as it soon loses its efficacy; solutions of alum, tincture of bark, solution of lunar caustic, aqua camphorata, &c, are often useful, and require to be applied as often as three times a day, or oftener if the disease is considerable.

By this term is generally understood a circumscribed enlargement in a part from disease, not strictly a disease of a natural circumscribed part, as a thickened diseased gland. Of circumscribed interstitial enlargements in common parts.— These seem to depend on an accumulation of extravasated coagulable lymph, either in the adipose or cellular membrane, or both. They are of two kinds; one is probably scrofulous, and not so circumscribed as the other. The wen is commonly found in the cellular membrane of every part, but how formed it is difficult to explain; perhaps there is an absorption of the natural original parts underneath. The increase of cancer is much in the same way; a good deal of the cancerous matter appears to mix with the natural parts; but these natural parts appear to be lost as the cancerous matter increases. The specific quality of wens is not yet known.* They retain their living properties, and sometimes swell to an enormous size; sometimes they remain stationary, and sometimes they become solid throughout, so as even to be as hard as cartilage; when cut into they look like a lemon, but not so regular; they seem to have no leading cause, constitutional or local. Calcareous earth is often deposited in them. The first mode of preventing them, if we

* [Sir Astley Cooper has described a species of encysted tumour or wen of the common integuments, which evidently depends on an obstruction of the follicular ducts of the skin, in consequence of which the sebaceous follicles become distended by the accumulation of morbid secretion. Ranula, and the enlargement of the labial glands, are analogous cases, and it is extremely probable that many other forms of tumour, such, for instance, as the serous cysts which are developed in the viscera, and the solid tubercles which occur in similar situations, owe their orgin to a like cause, that is, to an obstruction in the primary branches of the excretory ducts. In general, however, the origin of adventitious growths, (see note, p. 150,) and the distinction of their specific natures, is involved in much obscurity, so that every attempt which has yet been made to classify them according to their natures has failed. The truth of this observation respecting the classification of tumours has been generally felt, and will be perceived in the ensuing observations of the author.] OF SPECIFIC DISEASES, ETC. 331 had any, would be by resolution, both by topical and internal applications ; but we have none of much power in this respect. For those which are external, as in the cellular membrane, such remedies as were recommended in the diffused are proper; but these are more difficultly removed than the diffused, and, being circumscribed, are less capable of sympathy, and more indolent; perhaps mercury is the best resolvent for them; electricity is not so much to be depended on as mercury; suppuration of them, by cutting, or any other mode, will do no good. They produce a sore which it is impossible to heal, and which often becomes cancerous; therefore suppuration should be avoided, as it diffuses the cancerous disposition. Extirpation is the only remedy, so that the earlier this is acceded to the better. Their situation makes caution necessary, in the avoiding to wound surrounding parts. I have laid bare the carotid in the necks of women, also the temporals for two inches, and often have laid the trachea bare. By care and attention these operations are very easy and safe. The jugular vein I have also laid bare; but I would tie its two ends, as it is afterwards very apt to slough. Tubercles may be classed under the head of spurious tumours : they are most frequent in the viscera. They are mostly of the lymphatic kind, and are often formed in the lungs of young people, and sometimes grow to a considerable size: they are often on and in the liver, the spleen, the uterus, the coats of the intestines, the peritoneum, and sometimes on the epiploon: the lungs are frequently full of them, and they are the cause of most consumptions. How they are formed, and whether glandular or not, I cannot determine; but I think they arise from scrofulous dispositions taking place in the lungs : their texture is often smooth. Solid Tumours.—Tumours may be divided into solid and encysted, which are very different diseases. Solid tumours differ from wens in being an entirely new-formed substance, and of new structure. Their situations are three: 1st, on the skin, forming warts, which are also sometimes seen on the mouth, lips, and oesophagus; 2d, in the inside of membranes, or canals, which are termed polypi; 3d, in the cellular membrane of every part of the body. They commonly arise from one fixed point, as a root, and then spread out in all directions, if the surrounding parts allow of it. These tumours, formed in solid substances, are perfectly circumscribed; they are generally more detached from the cellular membrane than the lymphatic glands. 1st. Warts are external or superficial: they also form on the inside of the lips, beginning of the vagina, and prepuce. Warts differ, according as the cutis and the cuticle differ, in different parts: when these parts are firm, the warts are hard, as on the hands ; but if soft, the warts are soft, as on the mouth or lips. They appear to arise from the true skin of the parts, and generally arise from, and are fixed on, a small extent of surface, projecting considerably, so as sometimes to be even pendulous, with a narrow neck. In hard 332 HUNTER'S PRINCIPLES OF SURGERY. parts they arise only to a small height, and appear to split into many parts, and often by accident become painful, bleed, and inflame. Those on the penis sometimes have a broad basis, and rise not so high, and divide into points. On the inside of the labia pudendi they often grow very large. It is difficult to assign their cause, but sometimes we see an immediate cause, as the venereal disease in the genitals. 2d. Polypi arise on the canals, or passages, each of which seems to produce a kind peculiar to itself, as the nose, vagina, uterus, &c. ;* they are supposed also to arise in the urethra, and I have seen them in the rectum in men. They have generally small necks, and require extirpation; those from the Schneiderean membrane are generally in a cluster, numbers arising from the same root; internally they consist of a reticular membrane, whose interstices are filled with a watery fluid, and, besides this, an external covering, both of which coats are vascular, but more particularly the external. They are inconvenient according to their size, often causing a tickling in the nose, which excites sneezing; when large, they are evident to the eye, either externally or internally, appearing to be semitransparent bodies within the nostrils; but when protruded so low as to be exposed to the air, they become opake, &c, and are then sometimes supposed to be cancerous ; and, indeed, we should be cautious in extirpating them, as cancerous tumours are sometimes found in the nose. The best mode of removing them is with a forceps, but seldom more than one can be removed at the same time. If the polypus is forward, it must be extracted anteriorly by the nostril, the patient blowing the nostril as much as possible, to bring it forward. When the operation is simple, it is merely necessary to twist it off by a rotatory motion of the forceps. 3d. Of the third species.—This is an entirely new substance in the cellular membrane, often irregular, attached by loose cellular membrane to the surrounding parts; wre have also often such in bones which have been diseased : they seem to occasion the absorption of natural parts. Pressure often hinders their growth, and sometimes even occasions their removal by absorption; but this is not always efficacious, and then extirpation is the only remedy. When in soft parts, we use the knife, and each incision may go as close to the tumour as possible, the surrounding parts not at all sympathizing ; but if there is a root, then a little deeper: if the root goes to the surface of the bone, we cauterize it. On the bone, * [It is questioned by some pathologists whether polypi, analogous to those which arise from other mucous membranes, are ever found in the uterus ; at all events, those tumours which are usually called polypi of the uterus are ascertained to be of a different kind. These latter are in fact precisely similar in structure to the fibrous or fleshy tubercles so frequently found imbedded in the tissue of that organ, which vary in their appearance according to their situation, which allows them sometimes to assume the pedunculated form. This I think is rendered quite certain, from the fact that they occur en the outside of the uterus as well as on the inside, and in that case hang into the cavity of the pelvis just as in other cases they do into the cavity of the uterus.] OF SPECIFIC DISEASES, ETC. 333 pressure will keep them down, or even make them lower than the common surface of the surrounding bone. Tumours often arise and shoot out from the alveolar processes, and the alveolar process often takes on the ossific disposition along with them: sometimes, but not always, they have bony matter in them. On the Removal of Tumours.—We should first consider the kind of tumour and part; if a simple body, the knife is the best mode of removing it. The first difficulty in the mode of opening it is, at first setting out, to know whether one or two incisions should be made in the skin. One incision is often sufficient, and two are often necessary; one is sufficient where the tumour is small, or very loosely attached to surrounding parts; but two are necessary when the tumour is large, or where the skin is diseased over it, so as to confine it much, even if small, as on the head, or sole of the foot. A simple incision is sufficient in fatty tumours, except when very large. In the dissection of common tumours we need not be at all nice about the tumour, nor in removing any of the surrounding parts ; but in scirrhus, or cancer, the incision must be extended to surrounding parts, and this is not for convenience, but for the success of the operation. For these wounds there are two modes of treatment; some heal by the first intention, others by suppuration. The first, when the skin will cover the whole sore, bringing the ligatures out at the under angle, when any are required to secure the vessels ; but when the sides cannot be brought perfectly in contact, or when sloughing is expected, suppuration must take place; but in many such cases some part may still be healed by the first intention. Of Tumours in Bones.—Besides ossific inflammation, as before mentioned, we have sometimes tumours, arising from extravasation of blood or scrofulous inflammation. 1st. Those from extravasated blood appear sometimes to arise from the surface of the bone, or else from its substance. The bone becomes lost in proportion to the size of the tumour; which arises from an unnatural accumulation of matter pressing on the part, occasioning absorption : this is most remarkable when the tumour is on the inside of the bone, which then appears as if scooped out; and as the cavity enlarges by absorption, the body is in proportion accumulated. This kind of tumour, arising from disease, differs from that arising from accident, as from fractures, these not exciting ossific inflammation in the surrounding parts; except, indeed, when in the leg and thigh, where, strength and support being needed, Nature forms new bone to supply the deficiency of the old. I can hardly tell whether the extravasation of blood is a cause or effect. Bones will break from this kind of tumour by very slight causes, such as by turning in bed; for before the whole cavity of the bone is absorbed, the bone generally gives way, and is fractured by a very slight cause: after the bone gives way, the extravasation increases from the continued disease and new-ruptured vessels. This kind of fracture happened to the Archbishop of Canterbury. 334 HUNTER'S PRINCIPLES OF SURGERY.

Mr. Grindle has many examples of this in different bones in his possession. 2d. The second of these diseases in the bone which have the same appearance, is an accumulation of curdly substance ; probably it is coagulable lymph, and may be reckoned among the encysted tumours. The ossific inflammation often goes on here, till the bone acquires great size, but in these the outer ossific accumulation is not in proportion to the absorption, and therefore, being only a thin shell, it gives way; this is most common in the head of the tibia, and is called spina ventosa. Scrofula, attacking bones, makes them soft, and also thick, although their structure often remains; however, sometimes it is altered, scrofulous matter being deposited, and then the natural matter is removed, till at length all the matter which forms the bone becomes scrofulous. Such cases in a bone generally increase so much as to approach the skin, which inflames, ulcerates, and exposes the parts ; and this increases the internal disease, which neither nature nor art can possibly cure ; and then a hectic, sooner or later, according to the habit of the patient, seizes and destroys him. These two different causes, perhaps, have some connexion, yet the last is most scrofulous. In the treatment, we ought first to prevent the extravasation, &c.; but we neither know the disease, nor how to effect this intention. If known early, perhaps exposure and sea-bathing would be the best cure. 3d. These tumours are of two kinds : 1st, tumours simply, which are often scrofulous to appearance; 2d, the cancerous, which at present I defer. The first kind I have often seen, and most frequently in the lower jaw, and upper part of the tibia. The latter is probably a species of spina ventosa. If the disease seems to be true scrofula, then sea-bathing may cure it, but this is more difficultly known than in soft parts. When of the soft kind and convenient, pressure should be tried, which often is of great service, as in Mr. Squire's case ; but when this fails, electricity, or the mercurial ointment and camphor should be used ; and when this also fails, an operation often becomes necessary ; an incision should be made upon it, and it should then be dissected out as in scalping, as close to its root as possible, with a little of the surrounding parts with it. If from bone, it is impossible to remove any of it by the knife, and it becomes necessary to cauterize it. Sometimes a saw or pincers are necessary for its removal, and cauterization of the cavity afterwards. Encysted Tumours.—These commonly consist of a bag, or cyst, filled with a substance softer and different from the surrounding parts, though not necessarily so. The cysts are of too kinds, viz., natural and acquired. Natural, as the tunica vaginalis containing a fluid morbid in quality or quantity ; Fallopian tubes; the uterus or oviducts of animals; when, for instance, their foetus or eggs are preternaturally retained; these parts then taking on the nature of the coat of an encysted tumour. Sometimes they arise from an OF SPECIFIC DISEASES, ETC. 335 obstruction of the duct of some gland, which forms a tumour: I have seen them on the inside of the lip from this cause. The second, or acquired, are in consequence of disease in solid parts, and have much the feel of common tumours. It might be supposed they were common tumours suppurated; but they are original specific diseases. They contain varieties of matter; and hence they are divisible into several kinds: as, 1st, hydatid, from their contents being watery; 2d, various matters of different consistency; 3d, a curdly substance. The thickened cellular membrane, condensed by pressure, forms the coats of the first and second; but I know not how the third coat is formed: some of them probably are scrofulous : and if so they are no more than very indolent abscesses in those parts, having acquired a strong coat, which I think is sometimes the case. 1st. Hydatids vary in kind, from the variety of their situation. All accumulations of water in cavities, are properly hydatids. (See note, p. 229.) The water may either be in a natural cyst, as the tunica vaginalis, pericardium, &c, or in a cyst formed by disease. This second division is of two kinds, but both occur in the cellular membrane. The first is filled with serum, and therefore similar to the above; the second is lined with a peculiar substance. Those of the first kind are most frequent in those parts which have an enveloping membrane, as the abdomen and thorax; and are more common to some of these than to others, though it does not arise from their having a cavity, but from a peculiar disposition of these parts ; these hydatids project into the cavity. Those in the cellular membrane are very uncertain in their situation. The first kind, or simply watery, are often in women's necks, or in the thyroid gland. I once saw a large cluster in the neck of a woman. As they increase in size their coats increase in thickness: those in the cellular membrane thicken soonest: for the lining membranes, or cysts, only thicken by a species of adhesive inflammation. The second differ from the former, and are made up of two parts : the strong external coat is lined by another, of a dusky white colour, much like the retina of the eye, and gelatinous; this coat is generally as thick as thin pasteboard, and as strong as thick wet paper. In many hydatids there is an additional or third coat on the inside of this, which is less opake; and sometimes a fourth, and so on, till at last nothing is seen but coats; none of which, except the external one, is vascular. It is easy to account for the formation of the external coat; but difficult for the internal ones. Whether the external is the first, and the parent of the others, or the consequence, is not easily determined; but the last is most probably the case, as when formed, they stimulate so as to produce a vascular coat; but whichever is formed first, we must suppose that it is capable of continuance. I suppose the first formed is the nucleus, and so on; similar to a nest of pill-boxes, one within another. There is another somewhat similar, but more irregular ; the external vascular coat being full of small ones, as shown in 336 HUNTER'S PRINCIPLES OF SURGERY. this preparation [exhibiting it]. Does this last species proceed from indolence? Many animals die of them in the liver, in cold climates, especiallv sheep: it is in them called the rot. Hydatids cause little sensation, and are seldom knowm till of a considerable size. Hydatids of the Uterus.—Those of the uterus and ovaries are generally circumscribed bags,* and generally are numerous, especially in the ovaries, and appear somewhat similar to those of the scrotum ; forming a species of hydrocele of the part. At first they are thin, containing a transparent fluid; but afterwards they become thicker, and the fluid is bloody, or like a jelly. They have when small but little attachment, but afterwards get to adhere to each other, when they grow often very large, and increase the size of the belly, forming ovarian dropsy. The history and progress only of the case can in general distinguish it from ascites; at first there is a partial, moveable swelling, rolling from side to side in bed. Afterwards they become fixed, but even then, in thin people, inequalities may be felt; when large, they become fixed to the parietes of the abdomen ; and if the person is not very fat, a fluctuation may be felt. The health is but little affected by them. Hence the cause is very different from ascites, where the health is first injured. Tapping is only a palliative cure, and a large trocar is required, as the fluid is generally gelatinous, and then only one cell is opened. If taken in the incipient stage, they might be taken out, as they generally render life disagreeable for a year or two, and kill in the end. There is no reason why women should not bear spaying as well as other animals; it would be simply opening the cavity of the abdomen, which we often do without inconvenience in healthy constitutions-! Hydatids in the Kidneys.—They are of the first species, of the adventitious, and are generally situated between the first and second laminae of the external coat; but they are certainly often in the internal substance of the kidney. Sometimes there are a great number. Those in the coats are never detached or pendulous ; the

* [The hydatid which forms in the uterus is peculiar to that organ, at least in the generality of cases, being of a pedunculated form, and generally grouped together like a bunch of grapes. Hydatids in this situation often attain a great size in the aggregate, and are expelled by a parturient effort. There is reason for suspecting that this form of hydatids most frequently arises from impregnation, in which case the destruction of the ovum is almost universally the consequence.] f [This recommendation has been adopted in several cases, but the success has not been found to warrant its repetition. The difficulty of ascertaining whether one or both ovaries is affected, as well as the obscurity in which the disease is involved in its earliest stages, are insurmountable objections to the operation; for I do not suppose that any one would be so bold as to propose it after the cyst has attained any considerable magnitude. Besides, it sometimes happens that the disease remains stationary for many years; and in other cases a cure 19 effected by the suppuration of the cyst consequent on tapping, the danger of which is scarcely greater than that which would attend the operation of extirpation.] „ OF SPECIFIC DISEASES, ETC. 337 coats are thin, and look like a red grape; they give no symptoms of any kind, nor do they require or admit of any remedy. Sometimes those about the kidneys burst into its pelvis, and come away by the urethra. A gentleman had a considerable swelling on the left side of his belly which had been a long time collecting, and evidently contained a fluid ; on a sudden a considerable quantity of fluid was discharged from the bladder through the urethra, and along with it a large number of hydatids; some whole, others burst; but the swelling of his abdomen subsided and he got well: however, he afterwards filled again; but he again emptied them by the ureters, and he is now perfectly well. Hydatids of the Liver.—The liver may be said to have none but those of the second species of the adventitious; they are generally, but not always, on the exterior substance of this viscus. In some rare cases they have produced ascites by their coats bursting internally; and sometimes they have been discharged externally by their coats adhering to the peritoneum, and inflammation and suppuration coming on. When known to be a bag containing fluid it may be opened, but I would not be in a hurry to do this. Hydatids of the Lungs.—These are of two kinds : first, a collection of water simply in one or more cells; the second, of the adventitious kind, either external to, or in the substance of, the lungs. Some open into the trachea, and are coughed up in abundance ; sometimes they produce spurious empyema, when they should be opened pretty early, to prevent their affecting the substance of the lungs by pressure. Hydatids of the Brain.—These I have never seen increase so far as to cause inconvenience. In some animals they are common when young, and are successfully taken out. They are very frequent in the plexus choroides. Hydatids of the Thyroid Gland.—Sometimes these are very large, and produce difficult respiration and deglutition. Hydatids of the Cellular Membrane.—These are generally of the first species of the second division of the adventitious, containing a transparent fluid. Some parts, and more especially women's necks, are more subject to them than others. They are also pretty common on the inside of the lips of men. 2d. The second kind of encysted tumour contains matter of various kinds, and are very similar to hydatids, often containing in part a watery fluid. In the ovaries, fatty, cuticular, and hairy tumours are sometimes formed. The treatment for the two first is the same. From their situation we may divide their cure into two kinds ; one admitting of external applications, the other not; but I know no medicine which will cause their absorption. When external, therefore, the only means is opening them, when they will inflame, suppurate, and may be managed as in common hydrocele; but so much nicety is not here required, as the sac, being generally thick, will not collapse. In some a free opening is only necessary; sometimes they inflame 29 338 HUNTER'S PRINCIPLES OF SURGERY. spontaneously, but rarely, and even then a free opening is necessary, on account "of their indolence. If the sac is much thickened, the exposure by opening will generally kill it, and cause sloughing; yet exposure is not always sufficient, but the whole sac will require dissecting out, and especially when we consider that there is sometimes in these a cancerous disposition. Of the Cuticular.*—The adhering cellular membrane forming the sac, takes on the disposition of the cutis, or more properly is changed into cutis, and is capable of generating an external one when exposed; it is lined, indeed, with a cuticle. These cysts often have so much the disposition of the external part, as to have hair grow in them, which is the same as that which covers the animal, as, for instance, wool in the case of sheep. Every part of the body is subject to them, but some parts particularly so. The ovum is subject to all kinds of encysted tumours, and to these more than other parts; and they probably throw off the cuticle every year, or oftener, the cuticle being filled with hair. They are also filled with various matters; sometimes with a caseous substance, in others with oil, fat, bones, &c.: they occur also in the eyelids, in the skin near the eyes, and in the lips, and all grow to a large size. There are two methods of cure, one dissecting out the tumour, the other opening it freely, or taking off the projecting part and leaving the basis : on the eyelids, when very superficial, they often burst, matter is discharged, and they get well. On the head they are opened and get well. I have seen the external skin only taken off, which gave rise to an inflammation round its edge, which suppurated and granulated, and healed over, producing a cure. A gentleman had a large encysted tumour on the muscles of the abdomen ; this was opened by taking out a circular piece of the integuments, comprising the fore part of the sac. The wound of the integuments suppurated ; but the internal surface of the sac, which was now fully exposed, never suppurated the least, so that the wounds of the integuments granulated and healed, tucking down the integuments to the thin surface of the sac. The patient has remained well ever since; but has a large cicatrix, part of which is composed of what was the internal surface of the sac. The surface of the internal coats of these tumours has a skin somewhat like that which covers the glans penis, different in some respects from that with which the rest of the body is furnished, but not of such a nature as to suppurate on exposure. 3d. Encysted tumours, in a part depending on an indolent disposition or suppuration are commonly deep-seated, and their progress is very slow at first; they appear as an abscess, and might

* [The reader is referred to Cooper and Travers's "Surgical Essays," p. 215, for an account of encysted tumours forming on the scalp and face. These strictly come under the designation cuticular, and have been adverted to in a previous note, p. 330.] OF SPECIFIC DISEASES, ETC. 339 be suspected to be encysted, from their giving no pain. I have seen sometimes a chain of them leading from the skin; that nearest the skin appeared to be the original of them. These often deceive the surgeon, who is either satisfied by opening or dissecting them out, suspecting no more of them; and I know no characteristic mark of their presence when the original one is deep-seated; when external, the examination after the removal of the first may distinguish them. Of the Inflammation, Suppuration, and Ulceration of new-formed parts or substances.—We shall find these parts more liable to dissolve than the natural parts are, having weaker powers of action. In proportion, therefore, to the quantity of new matter, is the part weaker; and these parts go through their diseases much quicker than original ones. When new-formed parts are under the necessity of inflammation, a very slight cause is sufficient; and the inflammation goes on more rapidly than in original ones; and it requires more attention and care to stop its progress. They are both more ready to mortify and suppurate. If in the adipose membrane or skin, and the inflammation is beyond resolution, then no suppuration, but ulceration, takes place, and mortification rapidly ensues; but it will be confined to the new-formed part, except in very bad constitutions. When suppuration has taken place, or mortification, there must be also ulceration, which is very rapid; so that an abscess in parts where an abscess had been before, will be much quicker than before in pointing, or than in other sound parts: if mortification takes place, the separation will be almost immediate. Hence it appears that it is a deposit of matter originally from the constitution, and she lays a claim to it in removing it and repairing it again at pleasure. Simple fractures sometimes disunite, though stronger than by granulations : in these cases no inflammation is produced, at least not so much as to produce suppuration. Union of parts by granulations often disunite, both in soft and hard parts, hence old sores and old fractures disunite. This disposition of fractures to disunite is most frequent in the lower extremities; the substance appears to be shorter lived than the original part was, as in old sores, w7hich so frequently break out again. In parts united by simple extravasation, and adhesive inflammation, which again ulcerate, there is no suppurative inflammation, but there will be in parts united by granulations and suppurations. Ulceration, though frequent after compound fractures, is seldom so considerable as to destroy the new-formed bone wholly, though often in part; these are the causes of bad ulcers, and of what are called foul bones. It most commonly occurs from a fault in the general system, as scurvy; and upon this principle, sloughs take place soonest in newformed parts, the separation depending on ulceration. For the cure of these cases we must first examine into the causes: if from scurvy, when the patient is at sea; or if from their depending position and too much exercise, when the ulceration is in the legs ; in which case rest and a horizontal posture are to be used; but 340 HUNTER'S PRINCIPLES OF SURGERY. there is something very peculiar in the lower extremities; they will become better and yet again slough. Of Fistulae in general—The term fistula gives a very inadequate notion of the disease, the fistulous canal being only the sign of the disease,—the means of conveying a fluid or extraneous matter to the surface. A fistula is the consequence of the powers of a part not being able to remove the original eause, so that the original cause and some of its effects remain. The causes of fistula are various, but may be divided into two classes: first, the obstruction of the passage of some natural secretion, as fistula of the parotid gland ; or of the canal for the passage of extraneous matter, as the intestines being strangulated so as to mortify, or being wounded; but all obliteration of the ducts where the fluids make a new passage will not be termed fistulas: secondly, the formation of pus or extraneous matter in a part requiring a passage, as in fistula in ano, fistula in the joints, and fistula from diseased bone. We shall first consider the first cause of fistulae. 1st. The obliteration of ducts, or canals, is the first cause. This arises from obstruction of the natural passages, in consequence of which a new one is formed for the passage of the natural secretion. These obliterations often arise from a thickening of the sides of the ducts, as in the urethra, nasal duct, &c, from inflammation; sometimes from the venereal disease or scrofula; and sometimes from accident, as in the parotid duct. These obliterations are often very troublesome, obstructing the evacuation of the natural secretions, which is very teazing to the part, and when complete is very serious in its consequences. In most there is a new passage when complete, which is made by inflammation and ulceration ; these new passages are called fistulous: the discharge is the natural secretion, mixed with the pus from the inflamed vessels of the sides of the passage. If this new passage answers all the purposes of the original one, it cannot well be called fistulous; when from a mortified or wounded intestine, it is called an artificial anus; when in the perinaeum, it is for the passage of the urine. There are often accumulations of secreted juices besides the above, arising from the same causes, and producing the same consequences, yet not called fistulous. Of the Fistula Lachrymalis.—This arises from an obstruction taking place in the passage of the tears from the lachrymal sac into the nose. The causes are often foreign to the nature of the parts themselves, as the small-pox or measles. This I suppose not to originate, as has been supposed, from a pustule at the end or mouth of the duct, but from inflammation running along the duct and causing the sides of it to adhere; it also may arise from ulceration of the duct from a venereal or scrofulous disposition in the part; but most frequently from obliteration of the canal from inflammation. The tears not passing, the inner surface of the sac becomes stimulated OF SPECIFIC DISEASES, ETC. 341 by pressure and distention, and the salts of the tears, which have little or no effect while the sac is natural, when diseased irritate it and produce inflammation. The sac swells, suppurates, and opens externally, and discharges the tears by this opening till the natural passage opens or a new one is made. If the os unguis had been susceptible of the stimulus and had ulcerated, it would have been fortunate, but it only thickens to defend itself from the disease ; for we find Nature has made internal parts less susceptible of such stimuli, the ulceration only taking place next the skin, so that it would perhaps be better for us if Nature would sometimes vary from her usual course. This internal thickening is sometimes so great as to unite the external part of the nose to the septum, and render the operation of perforating the os unguis less successful. Opening the old passage seldom succeeds, as it is very liable to become diseased again, as in strictures in the urethra, which are so apt to recur; and here bougies cannot be had recourse to, occasionally, as in the urethra. The operation, however, should not be done precipitately, as the duct often clears of itself and the patient gets well. Of the Obliteration of the Ducts of the Glands of the Lip.—These glands lie immediately under the skin of the lips, and when there is an obliteration of any of these ducts, a tumour is formed, which sometimes bursts of itself. As the secretion goes on, the new opening cannot heal, and it is then, though improperly, called fistulous, as it does the office of the natural passage, and yet is often stopped again: sometimes th3y do not burst, and I have dissected them out; for although they occasion little pain they are very troublesome. Obliteration of the Ducts of Camper's Glands in the Female.—This may be the case in the male, and probably would occasion fistula in perinaso. An accumulation of slimy matter takes place, and the ducts swell just under the skin, on the inside of the labia, near the carunculae myrtiformes. They increase in size, and sometimes are mistaken for hernia : they should be opened before becoming very large, by a crucial incision : and to prevent their union by adhesion after opening, they should be touched with lunar caustic : perhaps a round hole made by the lapis septicus would answer better than an incision. They first appear like a little encysted tumour, which increasing, becomes so troublesome as to prevent the person sitting. A lady had a very large one, which was taken for a hernia of the foramen ovale. She went to Paris, where it was thought an abscess and opened. Obliteration of the Duct of the Parotid Gland.—The parotid gland, from its superficial situation as it passes over the masseter muscle, is very liable to be wounded. Such a wound will afterwards become the orifice of the duot, and will heal in part, to a fistulous size: the duct itself going to the mouth probably closes, as the saliva must then be lost; and as its flowing here is very inconvenient, it is necessary to direct it to the mouth, which may be done with a needle, threaded with a round thread passed to the 29* 342 HUNTER'S PRINCIPLES OF SURGERY.

bottom of the fistula, then directing it to the mouth and feeling for the point internally, pushing it to the finger and drawing it through, leaving the thread in; and perhaps it will be necessary to bring the thread out of the corner of the mouth, and to tie the two ends externally. The thread should be left in till the new duct has lost its healing disposition, and then heal the external one; but it may perhaps be necessary to make it a new surface before it will heal by making the fresh surfaces adhere by placing them in contact. 2d. The second species of fistula, or that from disease, arises from the disproportion in the disposition to heal of different parts, viz. the internal and the external; the skin healing, while the deeperseated parts, or seat of the disease, have no disposition for it. It may arise from two causes : 1st, from any extraneous substance in the inner parts; 2dly, from a diseased state of the original part, when the disease formed. The first happens in large deep-seated abscesses, which are prevented healing at the bottom by the pressure of the matter. The second has two causes, the first from the part being naturally indolent, as tendons: the second from a disease in parts naturally ready to heal, but the disease being deep-seated, the skin is more ready to heal than the bottom of the fistula, and thus obstructs the necessary free discharge. Fistula in Ano—Generally originates two or three inches up the side of the rectum. The first process is inflammation, and the formation of an abscess; then the matter comes down by the side of the gut, and opens on the buttock. Sometimes the gut is so diseased as to give way, and then we have an opening into it, which being the easiest and readiest way for the matter, it is thus discharged, and then we may have no external opening; but if there has been one, it does not heal. The cellular membrane about the anus is sometimes the seat of encysted tumours, which are mistaken for fistula, although they do not proceed from inflammation. The treatment differs in these two very considerably; the tumour is often opened or breaks, but the inner surfaces of the two are very different. The abscess only requires opening, and then cures itself; but the encysted tumour, when opened externally, generally becomes fistulous, and opening into the gut will often not succeed, if attention is not paid to make them heal from the bottom; therefore it is necessary to keep them well open by dressing, or the two divided parts will unite at the edges after opening. When a fistula in ano has both an external opening and an opening into the gut, surgeons are in general satisfied with opening from one to the other; but the fistula sometimes runs higher up by the side of the gut than the inner opening, and then we should not attend to this opening, but get to the bottom of the sinus. Fistula in Perinceo.—In whatever part of the urethra the seat of the disease is, whether the prostate gland, or the membranous or bulbous part, the external opening seldom heals as long as the seat of the disease has no disposition to heal. This, I apprehend, arises in most cases from sympathy with a disease in deeper-seated OF SPECIFIC DISEASES, ETC. 343 parts: or, in other words, a deep-seated disease is capable of stimulating superficial parts, so as to prevent the natural action for healino-. Let us compare this disease with the state of parts after lithotomy. If the incision is made in sound parts, and the whole injury be a stone, which is extracted, the parts readily heal, in spite of the urine passing through that channel. This, then, shows that there is another cause of their not healing. Now if the parts higher up are unsound, as the prostate, &c, though the incision was made in sound parts, it does not heal: if perchance it does, the disease still continuing, you will have probably two or three fistula?. If the parts are unsound beyond the fistulae, you will be continually plagued with a return of them. Bougies should not be kept in too long, as they sometimes make fresh fistulae in perinaso. Several fistulae may arise from one disease. A diseased bottom may have many fistulous sores leading to it both in the perinaeum and anus: and if one of these be laid freely open, so as to expose the diseased part, the rest will heal. When the disease is in one fixed part, there is a canal leading to it, which I have called a fistula; but if more than one, these different ones are called sinuses. A fistulous orifice is generally a small opening in the skin, having no sore surface in view, and is easily distinguished from other sores; if the diseased part is deep and of long standing, the external skin will be thickened more or less near the orifice, from the contraction of granulations within the canal, so that sometimes there is a protuberance even by the contraction. But this appearance is also common to all diseased parts some way under the skin, when the skin does not partake of the disease; when it does, this appearance is less considerable. If near a bone, this is suspected to be affected. When the seat of disease is near the skin, as when on the tibia, then we may be certain the diseased cavity below is not large. The cure of fistula consists in first removing the immediate cause ; for frequently they get well by simply removing the obstruction. In fistula lachrymalis, a new opening, or the restoration of the old one, is the cure. A fistula in perinaeo will often be cured by stretching and dilating the canal of the urethra by bougies, which removes the obstruction. The cause of our first division of fistulae, arising from confined matter, is sometimes easily removed, but not always, by opening the suppurated part in the most depending situation, when, if the parts are readily disposed to heal, a cure takes place. The second, from a diseased state, must have the disease removed or extirpated if possible; but this is often impracticable. A perfect exposure is the next object; but the case will not often admit of it, and then becoming incurable it sometimes produces hectic, as in lumbar abscesses, and abscesses of the liver, which open externally but cannot be exposed. The constitution in such cases is to be most attended to, and everything done to lessen the irritation; but in most cases life is miserable, and we only protract it a little longer by our best efforts. Fistulas in the lungs and liver in consequence 344 HUNTER'S PRINCIPLES OF SURGERY.

of abscess, and in the intestines from old obstruction, can only have their orifice kept open for the discharge of the matter. Fistulas in ano are generally easily come at, and are then of easy cure. At first it is simply an abscess from disease on the outside of the rectum ; if not, it becomes so by inflammation and suppuration. This is proved by the cure, which is not simply a free opening where the abscess points, but opening the abscess from its original seat is necessary for the cure: slitting up the gut to the origin of the abscess is necessary in all cases of fistula in ano.* Of the attention necessary in diseased and wounded Joints respecting their motion.—I shall now speak of the preservation and acquirement of motion in joints when diseased, and after disease. We must consider in both the necessity of removing the first cause of the disease, or we shall be increasing it by endeavouring to preserve or to acquire the lost motion: nothing can promote contraction of the joint so much as motion before the disease is removed. In healing wounds in general, and especially those connected with joints, great attention should be paid to the motion of the joint: when all inflammation is gone off, and healing has begun, a little motion, and frequently repeated, is necessary to prevent their healing in one position, Wherever there has been an inflammation, a stiffness will remain ; but the parts will stretch, and the motion again become free, by gradual motion and friction. But in healing of wounds by granulations there will be more rigidity. When there has been loss of substance, from mortification and gun-shot wounds, there will be still greater rigidity, and consequently more attention is requisite. In violent inflammation there is a union, by a broad surface and close contact, and then motion is sometimes altogether irrecoverable. The parts may often be made to stretch by degrees: this is either by active or passive motion. The active or muscular motion is insufficient, if the disease has existed long, as the muscles often lose the power of acting. The passive or foreign power may be of three kinds: 1st, the hands of another person; 2dly, the addition of matter to the moving part, so as to increase its momentum; 3dly, putting the moving part into such a position as to increase its gravity, which will produce the same effect as the two former; but yet the assistance of the muscles are necessary also. The position is either the middle state of action, which is natural in disease, or it is in consequence of gravity. The arm in diseases of the shoulder, if in bed, lies a little out; but if up, it hangs by the side naturally. Joints are of two kinds, some with flexors and extensors, with a given power; the other have not only the above, but a given support, which support acts generally in the centre of gravity. This division makes a material difference in the position of joints. If in the former of these there is a disease, the part naturally falls into a half-bent state, and w7ill heal so if not prevented;

* [The reason of this necessity is the constant action of the sphincter muscle, which is divided in the operation.] OF SPECIFIC DISEASES, ETC. 345 but it is different in the other kind, for in whatever position they are placed, when there is a weight, the weight becomes the object of the mind, and not the motion; and the joint must be kept wholly in this position, which is a position rather contrary to that which it was meant to be kept in. This is most remarkable in the anklejoint, because the point of support will not be the natural one: the foot will be hanging in a straight line with the leg, which is just the contrary to that which arises from the elongation of the muscles of the ankle. Suppose the elbow contracted, and I want to put the flexor muscles into an elongated state, neither the muscles nor mind being able to do this; the hand, apparently, is not heavy enough; but suppose I should then put a little weight into the hand, in order to assist a little, then the mind will be fixed on the weight to support it, the flexors will support it, being influenced by the mind; and thus we shall do harm by increasing the power of the flexors. But if the mind is fixed on the extensors, and not at all on the support of the weight, then the weight will be serviceable by extending the flexors while contracting the extensors. In the endeavour to elongate the muscles in any part of the body, they should never be allowed to contract, which would counteract the elongating powers. In contractions of the gastrocnemius muscle, the heel should be always supported, to take off the mind from the support of the body ; the body should be supported by art, by supporting the heel, but this should be incomplete, and gradually made more so. When the knee is bent, the above method will assist when the person is obliged to walk; for when sitting, throwing and swinging the limb about will assist most, and sometimes attaching a weight to the limb. I would advise lying on the face, and with such a position of the knee that the foot should touch the plane on which the body was, and then raising the foot more by bending the knee more. When the contraction is in the thigh, we cannot have all these auxiliaries. With respect to the shoulder it will be much the worst, as it will scarcely be possible to assist its position by any auxiliary. I.have thought a pulley might be contrived to raise the arm, with the weight fixed to the end of the cord; or the patient might be requested to lay on that side, having his arm through a tube and hanging out the other side. Every possible method should be tried: if a man could walk on his hands awhile, the arm would then by its own weight come to a right position with the body, which would be sufficient.

The symptoms of this disease are involuntary contractions of the voluntary muscles of the body, and sometimes of the involuntary, which makes it fatal. This affection is sometimes only partial, and at other times general. When on the muscles of the jaw, 346 HUNTER'S PRINCIPLES OF SURGERY. it is called locked jaw ; when on the fore part of the body, as the pectoral and anterior muscles of the neck, emprosthotonos ; when on the muscles of the back, drawing the head backwards, opisthotonos. Tetanus should first be properly arranged as to class and species. It may be properly classed with every unnatural contraction of muscles which may be called spasm, of which there are many species, most of which have some specific difference. It is of the same genus as spasmus cynicus, cramp, wry neck, subsultus tendinum, &c. It may be also classed with St. Vitus's dance, and it seems to have great affinity with ague, as this disease sometimes attends it; but the ague is only the predisponent, or immediate cause. It also seems to be allied to catalepsy and epilepsy: these arise from affections of the brain and nerves, but they may arise from different causes. Most of the above diseases are acted upon by affections of the mind, and this is sometimes the case with tetanus. This disease sometimes occurs in animals, as horses, cows, sheep, &c, from which it might be supposed that these animals were subject to it from their way of life being somewhat similar to man's. I had a stag which died from locked jaw, from a compound fractured leg. Some muscles are more liable to it than others; those of the lower jaw are the most so; but as the disease increases, another order of muscles is affected, which I think arises from a species of sympathy: other involuntary actions have also their predisposed parts, as the cramp, wdiich is mostly in the lower extremities. The muscles of the neck are most liable to that species of permanent contractions which constitutes the wry neck. Of the Causes of Tetanus.—The principal inquiries which have hitherto been made have been on the cure, and not on the nature of the disease, or its similarity to others. This part of the subject I shall now consider, and also in what climates it is most frequent. Irritation from an injury done to a nerve, ligament, or tendon is generally supposed to be the cause, as it generally occurs from wounds of tendinous or ligamentous parts. This at first would seem reasonable ; but we must determine first what is irritation. That is called irritation which excites inflammation, and a patient is said to be irritable when a part of the whole constitution is easily affected by any slight cause. But everything relative to locked jaw does not arise from irritation of the wound itself, neither from inflammation or symptomatic fever ; for in such states the constitution is not disposed to it. It arises from an irritable habit, which may be increased or produced by irritation, but not such as is capable of producing inflammation. When there is inflammation, the locked jaw arises only when that is subdued. When from causes incapable of exciting inflammation, the irritation may be considered the immediate, but not the remote cause ; for there must be a disposition for the disease, such a cause being insufficient for producing such effects : thus also madness is produced OF SPECIFIC DISEASES, ETC. 347 from the slightest causes when the mind is predisposed; so it is in agues and fevers, the constitution being particularly predisposed at the time to such diseases. If it were from inflammation, the locked jaw would come on at first, or when the inflammation is most violent; but then the constitution is strong, which is a state unfavourable to the disease. It is perhaps impossible to say what are all the remote causes which produce this effect; probably many combined ; and it would be impossible to give all the immediate, but I shall give as many of both as I have observed. Constitutions most susceptible of the Disease.—First, there is a disposition of the nerves, and that principally of the nerves of the voluntary muscles and sensation, rendering sensibility more acute in such, so that they can scarcely bear to be touched. This appears to be from irritability of the nerves, and not from irritability of the living principle. To produce the disease only a slight immediate cause is necessary, which is the case also in most irregular actions of the nervous system, as we see in tickling, which will produce convulsions, though these would not be produced by a bruise in the same part. Those most susceptible of the disease are of weakly delicate frames and of suspicious minds, and not of strong and robust ones. It is common to have involuntary actions of the muscles in weakly constitutions, as we see in pregnant women, who are subject to cramps, fits, &c, although the living principle is acting at the same time vigorously; this was also the case with myself, at a time when weak. I threw a stone at a deer, and overexercised the muscles of the arm, which produced cramp and extravasation in my arm, and loss of the use of the muscles: this produced sickness and paleness, and after a little time cramp came on in my leg; but at last this and the other symptoms went gradually off: if the irritation had continued, a locked jaw might have come on. Now here, from the irritation, a spasmodic affection was produced in a person in health. This species of irritation is very different from irritation of the living principle causing inflammation. Climate seems the first of the predisposing causes, and that which can probably produce it without other causes: the second is the consequence of considerable local inflammation : the third is irritation. The immediate cause is often a small wound of a part possessing but little living powers. In warm climates it is most frequent, and consequently it is seldom found in cold weather. In the West Indies and in the Mediterranean, besides tetanus, we also find the diseases with which I have classed it very frequent. Sweden, Denmark, and other cold climates are not subject to it. The cramp is most frequent in warm climates, and also in bed: fits also are most frequent in bed, for warmth seems to have a peculiar effect in producing a particular disposition in the nerves ; and when there is an immediate slight cause, such diseases readily take place: nay, some are disposed to such actions without any immediate cause, which probably arises from climate, joined with a strong natural predisposition. The cases which I have seen from wounds were 348 HUNTER'S PRINCIPLES OF SURGERY.

those of the tendons, for these parts heal less readily, and the constitution is much weakened by wounds of such parts, so that sometimes a limb will waste from such a cause,—wounds being much more irritable here than in other parts, and particularly when attended with loss of blood. Nothing produces irritability more than a great loss of blood, especially when accompanied with a wound, and with this disposition of constitution. The wounds producing it are either considerable or slight: the first is a predisponent, the second an immediate cause. When I have seen it from the first, it was after the inflammatory stage, and when good suppuration was come on; in some where it had nearly healed, and the patient was considered healthy, under the disease as well as before. Some have had locked jaw after the healing was completed. In such I have supposed the inflammation was the predisponent cause, rendering the nervous system irritable as soon as it was removed. When it comes on in horses, as after docking, it is after the wound has suppurated, and begun to heal. A young man burned his face with gun-powder: in a fortnight after he was nearly well; but a short time after a locked jaw came on, and continued for two months, and then recovered ; but before that time his wounds were perfectly healed. It arises from slight wounds, before either inflammation or suppuration comes on. A man had a locked jaw about a fortnight after a nail entered the sole of his foot, which he did not at the time regard as of any consequence, the wound not being larger than that from bleeding, and not attended with any pain, inflammation, or hardness: he died; and after death I found a black line continued to a hard body under the skin, which could be dissected out almost like a lymphatic gland, and was found to be a bit of leather, surrounded by coagulable lymph: the black line wTas the mark of the nail. Here was no pain which could be the cause, and little, if any, inflammation, and the suppuration had not begun: hence it appears that the spasm arose from the slight irritation. Would producing a greater irritation have prevented or cured in this case? or would dissecting out the extraneous body have done this?* These two kinds of wounds appear very dissimilar: I consider that the inflammation is the predisponent cause in the large ones, and that in the case of slight wounds there must already exist a predisposition, which only requires an immediate cause to bring it into action. The disease oftener arises from slight wounds than large ones, which may partly, but not entirely, arise from such being most frequent. Locked jaw arises from other weakening causes; it sometimes arises at the termination of a fever, and also at the termination of a flux, which is one of the most weakening diseases we have. It is singular that it should begin in the muscles of the lower jaw, and extend from these as a centre; but this is not a * [We should probably answer this question in the negative, considering that the progress of the symptoms is not in any degree checked by the entire removal of the irritation by amputation of the injured part. The fatal result, on the contrary, is generally precipitated by this means.] OF SPECIFIC DISEASES, ETC. 349

general rule, as it has been known to begin in the muscles of the neck. When it is confined to the muscles first attacked it may then be considered as mild. Tetanus appears to have a dangerous period, in which it is most liable to attack vital parts, which period seems to be before the constitution has become much accustomed to it; when of longer continuance, not having attacked vital parts, its liability to attack them seems lessened, which is generally in a fortnight, as the constitution has then become accustomed to the spasms, and can better bear them: I have never seen one die where it had existed three weeks, and after this it often continues, sometimes for several months. Sometimes they may recover in three days, which is generally the most fatal period ; but sometimes they may go on three weeks, and afterwards recover. If violent, it kills about the third or fourth day from the attack. As it appears to attack parts not necessary to life, it seems strange how it kills; and, seemingly, the patient is in good health at the time without inflammation, and with a good appetite; and, yet, though not starved to death, from the difficulty of deglutition, it kills: however, it is sometimes combined with other, diseases, and then it is difficult to say which disease kills ; but when it is alone, the following seems to be the case: the disposition increases, and the effect, spreading to vital parts, affects the muscles of respiration, as the diaphragm and intercostal and abdominal muscles, as we see in gout when it attacks a vital part. The first symptom is a stiffness in the muscles of the lower jaw, or neck; but before the patient is sensible of it, its progress is generally gone some length, not having had occasion to open the mouth wide, for when it is perceived it is probably only by accident: this stiffness makes the articulation imperfect. When the spasm is perceived, a hardness may be felt in the temporal and masseter muscles, and most of the muscles of the face become contracted: if it extends, the muscles posteriorly on the neck become stiff, consequently the head is erect, and generally drawn backwards; the spasm extending to the muscles of the back, it becomes one concave arch, preventing the patient from lying on his back, and a heavy pain is felt at the lower part of the sternum, from the spasm probably of the diaphragm: from this and the abdominal muscles being contracted, respiration is almost suspended, and the pain is similar to that of the cramp. By this pain, and the dyspnoea, we judge of the muscles of respiration and the diaphragm being affected. General spasms next come on, as subsultus tendinum, cold sweats, and death; and it is remarkable that the patient generally, if not always, retains his reasoning faculties during the whole progress. Of the Treatment.—All the antispasmodics have been given, but without apparent success; opium has kept its ground the longest, but with little reason, as it only quiets; but from some patients having got well under its use, its name has been raised: I have tried it, both in large and small doses, though always unsuccessfully. I 30 350 HUNTER'S PRINCIPLES OF SURGERY. think medicines have no power without they produce some visible effect: opium never removes the cause, though it will prevent the effects; it cures spasms, and removes pain, but it does not remove the cause. It often does good, by not allowing the symptoms to do harm to the constitution. The first appearance of a cure is a recovery of strength, as weakness is a predisposing cause; and the first indication should be to strengthen the system. I should recommend everything to produce extreme external cold, as cold applications, consisting of snow with salt, to the part, and that the patient should be put into an ice-house or sent to a cold climate as soon as possible.* I know of no internal medicine. The pain is somewhat relieved by counteracting the violent contraction of the muscles: opening the mouth by force has eased it; but this has also killed, by causing a translation of the disease: keeping the back bent has also given ease ; but these have relieved only in the incipient state. Electricity has a temporary effect, in relaxing the muscles, and in partial affections has cured, by rendering the contractions gradually less violent. A man fractured his arm, and about a fortnight after had symptoms of a locked jaw. I found several pieces of bone in the wound, which I supposed produced irritation ; these I extracted, and gave two grains of opium every two hours, dressed the wound with tinctura thebaica, and over all applied a poultice; he continued as bad as before. The next day I directed bark and opium : on the fourth day he was better; on the fifth much more so, and his pulse good: he was bled, which was repeated on the sixth, immediately after which he fell into a fit, and died in half an hour. This sudden change could not be from the loss of blood, though assisted by it, and by his natural aversion to bleeding: he was of a nervous constitution, and his spirits were easily affected. It was probable that this affection of the nerves was transferred to the heart and brain, and probably the mind had something to do in this business. In another case of locked jaw I gave three grains of opium every quarter of an hour, but the patient died ; the opium had no effect, and the muscles were not relaxed by death. On opening him no preternatural appearances were found. In one case I tried saccharum Saturni, because lead produces paralysis, and as I conceived the locked jaw a disease directly opposite to paralysis; I gave it in pills, and it produced costiveness, and a peculiar sensation: a glyster relieved him, and he was better, and they omitted the pills because he supposed they made him costive, and would not be persuaded to take any more. He was at last seized in the night with a difficulty of

* [A remarkable case of tetanus, which was cured by an accidental exposure to cold and inclement weather for upwards of sixteen hours, is related by Sir James Macgrioor in the 6th vol. of the Medico-Chirurgical Transactions, p. 450. Dr. Elliotson has also alluded to a case of tetanus in a horse, which recovered under nearly similar circumstances. Med. Gaz., Vol. XL, p. 474. It is needless, however, to say that not any remedy has yet been discovered which is uniformly] or even generally, successful in controlling the symptoms of this disease.] OF SCROFULA. 351 breathing, and spasms on the abdominal muscles, which killed him. In this case I lamented that the lead could not be continued. The ol. animale has been tried, unsuccessfully. I attended another patient in England, with Sir N. Thomas. Asafcetida and opium were given without effect; these were left off, and bark given in large quantities. Dr. Warren being called in, advised, among other things, a bath prepared of milk and water. After this he seemed better, but died soon after. I discovered, to my amazement, the different modes of different physicians. Sir N. Thomas had read much, and knew all the antispasmodics from the days of Hippocrates downwards. Dr. Warren having just cured his son of locked jaw, implicitly followed the same practice in this case, being unable to alter his rules of practice in the smallest degree, as occasion might require. CHAPTER XXI.

Symptoms well marked, and usually easily distinguished ',—tl specific disease, but without a morbid poison;—appears to have a sedative quality ;—not confined to man;—certain constitutions most susceptible of it;—certain parts most liable to its attacks;—certain ages also ;—not proved to be hereditary ; __climate a predisposing cause;—and season ;—immediate causes numerous. —Inflammation of scrofula;—suppuration;—pus;—ulceration;—cicatrization; __difference according to the nature of parts.—Disease of the hip.—Lumbar abscess.—White swelling.—Consumption.—Scrofulous testicle ;—scrofulous breast;—distinguished from cancerous testicle and breast.—Cure of scrofula; —warm climate;—medicine;—sea-bathing;—regimen;—local applications ; —surgical treatment

Scrofula is so well marked, and has so many characteristics, that few can mistake it; yet I suspect there are three diseases which have a great affinity to it, viz. spina ventosa, exostosis, and rickets. The first seems to be a pure case of scrofulous suppuration in bones ; the two last to be only varieties of scrofula. Scrofula is to be classed as a specific disease, but not as a poisonous one. It has, in a degree, the power of making neighbouring parts sympathise, by continued sympathy. It seems to have resident in it a sedative quality, as the disease goes on without any increased action, and from there being no adhesive inflammation. The pus which is formed passes along the interstices of the muscles, and is there even incapable of irritating. Other animals, besides the human subject, are liable to it, and probably from the same causes; thus, we find a disease very similar to it in young turkeys, and also in monkeys, and I had once a young boar which died of a similar disease ; that is, it had swelled 352 HUNTER'S PRINCIPLES OF SURGERY. lymphatic glands almost everywhere, and thickenings of the joints, like white swellings : but every constitution is not equally susceptible of it, although probably every constitution is more or less susceptible of it. In some there is peculiar susceptibility, so as to have it produced by a slight immediate cause ; but this susceptibility is lost by age. So, likewise, some parts are more susceptible of it than others. Those most susceptible of scrofula are the delicate, who cannot bear much fatigue or cold without being affected, who are very irritable, and cannot bear strong impressions, as of mercury, who are of irritable minds, light-haired, and of fair complexions. In fair people there is a more languid circulation than in dark, and they would appear to have less red blood. When it attacks after the age of puberty it seems not so much confined to colour. When it attacks dark people I think they have a thin skin. Every part has in some degree its specific disease, and this disease has its parts. Some parts are even disposed to it without the above causes, even by the slightest accident. 1st. The lymphatic glands, particularly the superficial, and those most exposed, as those of the neck and lungs, which last may be reckoned external. As the office of these glands seems to be for giving passage to the absorbents, with their contents, it might be supposed it was only dependent on absorption ; but as this is a specific disease, and not confined to these parts, we must look for another cause, and then too the lymphatic vessels might be supposed subject to it; which they are not; hence these glands must have some specific properties rendering them liable to it. Joints also are particularly liable to it, and especially those of the feet and hands, from their having so many joints, with ligaments and tendons. The elbow and knee come in next, and sometimes the hip and shoulder, and frequently the vertebrae. In short, every part is subject to it, but no part more than another, except the above mentioned. The skin has less disposition to it than any other part, for the skin will resist the neighbouring disease for a long time. Although all ages under the above circumstances are in some degree subject to it, yet youth is more particularly so, for beyond the age of fifteen the disease is less frequent, although it will occur from that period up to forty; few cases, however, occur above forty-six. In youth it principally attacks the lymphatic glands ; at a later period, the testicle; and the same things happens in other animals. I do not think that scrofula can be proved to be hereditary, for if we compare the number of scrofulous subjects who have, and who have not scrofulous parents, we shall find them pretty nearly equal. I have known many families where it has arisen spontaneously, the parents or predecessors having never been subject to it; and on the other hand, I have known parents who have had it, and their children have perfectly escaped. It certainly often runs in families, but only when the natural predisposition and immediate causes are present; fair delicate children will probably have it by OF SCROFULA. 353 the influence of climate. An hereditary disease should act universally ; it should pass to all the descendants of a diseased parent; to the dark as well the fair complexioned; to the old and young, and in all countries and climates alike. The children may have the predisposition, but this does not come up to the meaning of hereditary disease. It is only the predisposing cause which can be hereditary. It is hereditary for people to be born with lymphatic glands, but it is not necessary for people to be born with them diseased. Probably a susceptibility of peculiar irritations may be hereditary, as we see in families with regard to small-pox, &c.; but this is an infectious disease. The weak and delicate are incapable of supporting the changes of temperate climates: the most delicate go into this disease, and the parts most subject to it are those which are the most delicate. Climate may be considered both as an immediate and a predisponent cause: the different kinds of weather, as damp and cold, seem to be the great disposers to the disease; however, in cold climates, where there is most constant dryness, it is less frequent. That irregularity of cold and moisture is one of the greatest disposers to it, is evident, from its never happening in warm climates; but the inhabitants of warm climates coming into cold ones often become affected with it. Some parts of the same country are more subject to it than others, which is also the case in other diseases, as agues, consumption, &c. The animals of warm climates often die of indurated lymphatic glands when brought to cold ones, as turkeys, the joints of their toes being first affected, in a similar manner to white swellings. The disease which is called the pip in fowls is also the scrofula. The seasons likewise have considerable effect; for, indeed, they may be said to form temporary climates in some parts of the earth. Thus, in summer the disease is less frequent than in winter, and often that which is produced in winter is carried off by summer. But the regular cold of winter does not affect these people so much as spring, for the spring disturbs the constitution, and rouses parts disposed to scrofulous action similarly to a slight fever. The autumn has the same effect as the spring, but not so powerful. Every unnatural affection of the constitution has the power, in some degree, of calling forth scrofula; but the disease is never an act of the constitution. Though there is constantly a constitutional susceptibility, its effects are always local. It is a constitutional local susceptibility. Scrofula appears spontaneously to arise up every day, the susceptibility in some being so strong that by the simple continuance of the immediate predisposing circumstance (climate) they fall into it, without any other immediate cause. The immediate causes are many. Everything capable of producing unnatural actions in a part is capable of exciting scrofulous action where the susceptibility exists; thus, the fevers of small-pox, measles, and chickenpox often produce it. The lues produces scrofulous buboes; the irritation of mercury in curing the lues produces nodes; cold also 354 HUNTER'S PRINCIPLES OF SURGERY.

produces it, principally in the glands of the lungs or neck; and strains, gout, and rheumatism often leave the affected parts in a scrofulous state. These causes are more violent than that of climate, and produce the disease usually from a pretty considerable irritation, attended with inflammation arising from the accident, combined with that of the specific kind; but the swelling soon becomes indolent, so that it does not soon get well, and if opened, the sore is still not healable. We should therefore avoid opening it as long as possible. The true scrofula seems attended with little or no inflammation; or if it is so, its sedative quality prevents it from producing pain ; but when there is less of the true scrofula, it may give pain; however, it is attended with many of the effects of inflammation, as extravasation of coagulable lymph, producing swelling and also adhesion of the cellular membrane, or of the sides of circumscribed cavities. I have seen the whole of the intestines adhering to the peritoneum, seemingly from a scrofulous cause, and having scrofulous tumours and suppurations in them also: the symptoms were tightness in the belly, without pain and costiveness; at other times purging. The adhesions in the lungs of consumptive people are probably of this kind. Their indolence and want of pain led me to suspect that scrofula has sedative qualities which it gives to the matter, which does not irritate the parts unconnected with the disease. Where the inflammation is visible its colour is of a purplish red, which is a proof of a languid circulation. The progress of scrofula is commonly very slow, but sometimes the lymphatic glands swell considerably in one night; but then there is a quick and immediate exciting cause, such as cold or fever, in which case there is common inflammation joined with the specific, which soon leads to suppuration, although after the phlegmonous inflammation is gone off it becomes truly scrofulous. The swelling at first is interstitial, but after some time there appears to be a change of structure, as in the lymphatic glands, the testis, and more particularly the bones, the whole bony structure of which is absorbed, so as to leave nothing but a true scrofulous deposit, similar in appearance to a scrofulous gland. When in the extremities of the joints, the part in view is thickened, with little pain; this is principally seated in the ligaments; the joint loses its motion, and the whole limb becomes weak and wastes away. Scrofulous suppuration is very imperfect if it is truly of this kind, and there is often none at all. The extreme parts may lose their life entirely; yet they do not mortify, but form a curdly matter, similar to that in encysted tumours. This want or loss of life, if there was no specific action, would cause inflammation, as other dead parts would; but scrofulous parts are incapable of this stimulus. Many scrofulous tumours suppurate and ulcerate, especially when near the skin ; but this is not entirely the suppuration of the original disease, but from the inflammation of the neighbouring parts. The matter, like common matter, is often a mixture OF SCROFULA. 355 of pus with coagulable lymph, which last is often most in quantity, it is a kind of glairy and often a curdly matter, being a mixture of the solid parts which are dead with the vitiated secretion. The ulceration is generally very slow, and when near the skin is often stationary, even after the appearance of redness ; sometimes it will remain in this state for several months, with a broad surface, not coming to a point, the skin assuming a shining purplish hue; but there is no absorption of the matter, as is generally supposed, from the scrofulous indolence. It seldom happens that granulations form, the sore remaining months, and sometimes years, without any. When formed, they look transparent, as if loaded with water, and have little power of contraction. The cicatrization is as slow as the other processes, from the essential and leading steps to it being backward. The skin around loses its natural elasticity, and so does not give to the contiguous granulations a skinning disposition. To describe the appearance of scrofulous tumours and sores is impossible, but we can easily distinguish them by sight. A scrofulous swelling generally begins in one of three ways: first, by a circumscribed tumour ; secondly by a more diffused tumefaction ; thirdly, by suppuration, without any tumefaction. These all frequently appear in the same person at once. The first is seated in the lymphatic glands, and assumes this form from the part being circumscribed, and also because the parts do not give the stimulus by contiguous sympathy to the adjoining dissimilar parts ; but there are some which seem scrofulous, and yet are not in the lymphatic glands. These I have called tumours; as, for example, those in the uterus, the breasts, &c. Of the second kind are scrofulous joints, and the diffused swellings on the skin, toes, fingers, hands, and also on the testicle; although, when the whole testicle is affected, it is generally circumscribed. Of the third kind are certain loose bags of matter, without any tumefaction to distinguish them, although near the skin ; these are often pretty deep, and therefore are adapted to the parts they are in. There is no true adhesive inflammation in these cases, when they occur in true scrofulous habits. In the breast it begins like a scirrhus, and is sometimes taken for one; but it has no pain, and is so gradual in its growth that it produces no tumour in the axilla, so that it may be safely removed. In the testicles it often goes off and returns again. The second kind, when near the skin, often ulcerates, and hollows the skin by the cellular membrane, giving way more readily than the skin; so that when suppuration comes on, the swelling does not subside, as in other cases. When in a bone, it is generally very slow, and the matter consists of a curdly substance. If the bone is dead, exfoliation is very slow, and in such cases the bone is eaten away by the exfoliations, as we mentioned when on the subject of exfoliations; that is, the absorbents of the surrounding granulations take it up. The different appearances in scrofula will vary according to the 356 HUNTER'S PRINCIPLES OF SURGERY.

nature of the part, and to these we have given different names; scrofula in the joints we have called white swelling; in the loins, lumbar abscess; in the lungs, consumption; in the hip, hip-case. Some of these are not suspected to be scrofulous. When it attacks particular parts, it produces symptoms peculiar to the part; but in some parts which are not very necessary to health, it is not easily discovered. If the extremities are attacked, we find a lameness; and if a joint, a wasting of the limb. When it attacks visible joints, it is in general easily known; when it attacks the knee, it has commonly true inflammation conjoined with it, probably from its being frequently excited by accidents. Disease of the Hip.—In most cases of lameness, or wasting of the lower extremities, the affected limb appears longer than the other, in consequence of the patient pressing most on the sound limb, and putting the diseased one further out from the pelvis, so as to raise the ilium. This is particularly the case in diseases of the hip, although the leg is not found to be longer than the other, if the patient is laid on the back. It arises from the centre of motion in the pelvis being rather altered by habit, which is removed if laid on the back. But sometimes, when the muscles are much wasted, the limb is shorter, which I cannot account for, nor why the limb is sometimes drawn up more, and sometimes put out further than the other. Mr. Cline says the limb is actually longer and shorter in different stages of the disease, and accounts for it thus: in the first instance, inflammation takes place in the ligaments of the joints, occasioning the parts to swell, and a large quantity of synovia to be accumulated in the joint, which displaces and pushes out the head of the femur, thus occasioning a lengthening of the limb; but as the disease advances, absorption takes place, not only of the accumulated synovia, but also of the bone itself, with the surrounding ligaments; and the head of the bone being drawn into the newenlarged cavity, by the action of the gluteus and other muscles, occasions a shortening of the limb; and this lengthening and shortening of the limb is peculiarly evident on laying the patient on the belly. The glands in the groin of the affected limb becomes enlarged, from absorption of the matter. The first appearance of scrofula in the hip is announced by a weakness in the limb, followed by a wasting; but sometimes there is a thickening of the surrounding parts before suppuration comes. It is sometimes difficult to distinguish it from lumbar abscess, which I shall next proceed to speak of. Lumbar Abscesses.—The mode of their coming on evidently proves them to be scrofulous: lumbar abscess comes on almost insensibly, but sometimes the patient can remember a pain in the part, a pain on the knee, or a pain on the outside of the thigh, leading to the foot. These are often called growing pains, which shows that the disease is affecting other parts; which symptoms, arising from sympathy, are often more severe than the original disease. The progress is often so slow, that the weakness is frequently not OF SCROFULA. 357 apparent even when matter is approaching the surface, as on the thigh or loins. It often arises or is caused by injuries, as strains; in which case it is attended with more than usual sensibility and weakness. Its occasional removal by sea-bathing proves it to be scrofulous. It seldom occurs after thirty years of age, except from accident, so that it is most frequently met with in young subjects, who have other symptoms of scrofula. White Swelling, in its beginning and progress, is generally similar to other scrofulous cases; stealing, as it were, upon the part, and occasioning stiffness. There is sometimes a fluctuation with pain, but then it is not truly scrofulous; the pain is sometimes scarcely perceivable, but at other times it is considerable. These cases are of two kinds, one of which is truly scrofulous, the other is only common inflammation, mixed with more or less of scrofula; the latter terminates in adhesion or suppuration. In scrofulous sores on the fingers of children, the pieces of bone are often destroyed, and come away insensibly, the finger becoming shorter and alarming the friends, to whom it is necessary that we should explain the circumstance. Of Consumption.—Most consumptions are of a scrofulous nature, which is evident from the attending circumstances and cure. They are very frequent, in this and other scrofulous climates, in the fair and delicate, and in the young and middle-aged. They come on generally in a true scrofulous way by catching cold. By this the glands in the neck are enlarged, at the same time that tubercles form in the lungs, which afford a scrofulous secretion, or are converted into a curdly substance, which in the end ulcerates and opens into the bronchi. Sometimes thay occasion pain, and generally a cough, difficult respiration, and expectoration. The pain is considerable if the immediate cause is violent, as great cold; and the dyspnoea and cough will be according to the degree of inflammation. The spitting varies according to the inflammation, being at first mucous, but after ulceration is formed purulent. The patients generally die ; but as all consumptions are not scrofulous, we should distinguish them. The diagnosis may be formed by the violence or mildness of the attack; by the slow or rapid progress of the disease; by the degree of pain in some one part, and by the hardness and quickness of the pulse, &c. Spitting of blood, which is sometimes violent, at other times trifling, is not always followed by a consumption. Does this bleeding arise from a disease in the lungs, or from a small vessel giving way ? I cannot answer this question ; but this I know, that such symptoms often precede a consumption. If the lungs are affected, the symptoms will arise from the functions of the,part being impeded, as difficult respiration. When we examine consumptive people after death, we generally find a true scrofulous appearance; and as it is clearly scrofulous, it admits only of one mode of cure, which strengthens the opinion of its being scrofulous. The physicians here keep their patients as long as they can, and then send them away to Bristol and other places to 358 HUNTER'S PRINCIPLES OF SURGERY, die. But, if we see the symptoms pretty early, and consider it as scrofula fallen on parts which are essential to life, we should not trifle with it as with a finger; we should send them to a warm climate at once, or near to the sea-side; for bathing and short voyages tend much to cure scrofula, and consequently to cure consumption. Bleeding, however, is often necessary, to proportionate the quantity of blood to the quantity the lungs are able to circulate; otherwise bleeding is very injurious, as tending to produce greater weakness, when already great delicacy exists. Of the Scrofulous Testicle.—The testicle is the next part in order of susceptibility for the disease, and when so affected has been often supposed to be cancerous. Scrofulous testicles begin with out any visible cause, are slow in progress, and are often cured by seabathing : when they suppurate, the suppuration is scrofulous. I have seen them in lads of sixteen years of age, but never sooner; from whence we might think that they are not scrofulous. They are seldom seen in old people: for as the action of the testicle before and after puberty differs, its diseases probably differ also. Of the Scrofulous Breast.—I have only seen one truly scrofulous breast, which came on at the age of twenty-six, and increased gradually to thirty-eight. It was sixteen or eighteen pounds in weight. In this case there was no disease leading to the axilla, as in cancer; so that I dissected it out, and it healed kindly, although the patient had other scrofulous appearances at the time. It was perfectly circumscribed, which is never the case with cancer, when of any size. Cancer may be so at first, when small and loose in the cellular membrane : but when as large as a large egg, it affects the surrounding parts, and is more diffused. True scrofula, however, if attended with inflammation, will also adhere, and diffuse and lose itself in the surrounding parts, so as to put on a cancerous appearance. Diagnosis between Scrofula and Cancer in the Testicles and Breasts.—A cancerous testicle affects the absorbents going from the testicle and the spermatic cord; but I do not think that this is universal, since we sometimes find the cord unaffected, but in scrofula it is never enlarged or affected at all. The distinction, however, in some cases, is very difficult. As we operate in cancerous cases because the cord is sound, so we must often do so in scrofulous cases which have no cancerous disposition. In the scrofulous breast we have no thickening leading to the axilla, or in the axillary glands, but in cancer they are thickened from continued sympathy; and this is, perhaps, the best criterion. From the circumstance of the cancerous disposition spreading by what I call continued sympathy, the surrounding parts being contaminated and taken in with the original disease, the skin in all these parts takes on the same disease with the cancer; but in scrofula it does not do so strongly: therefore when a cancer breaks it spreads, but in scrofula the skin seems rather to have a disposition to heal. OF SCROFULA. 359 Of the Cure of Scrofula.—The remedies must be directed both to the constitution and to the part affected; but if we had a specific medicine, then attacking the constitution alone would be sufficient, as it is in the venereal disease. As to external parts, the only certain cure is extirpation, and this is very confined and is often improper, because the parts frequently get well of themselves ; still we are often obliged to have recourse to this means. Internal medicines have very little power; they cannot alter the constitution of fair people, or prevent the effects of climate, or change the disposition of parts; neither can they make young people old. They can only lessen the susceptibility of the constitution, but do not reach the cause; hence there will soon be a relapse, if they are discontinued, climate being often of itself an immediate cause of the disease. We'can sometimes affect the constitution by changing the climate; but changing the climate will not always effect a cure, for when vital parts are affected it is seldom done till too late. Change of climate is equally necessary in other cases as in tubercles of the lungs, these all depending on the same constitutional disease. Scrofulous patients should go towards the South, or near the sea-side, or take short voyages. Sea-bathing in consumption appears tremendous, but it should be adopted in a warm climate. When these means cannot be complied with, strengthening remedies are useful, as bark and cicuta, with cold bathing ; but these have no specific effects. Mezereon seems to have great power in the cure of this disease : a man with a very large swelled elbow, which appeared to be scrofulous, (although he had more pain than is usual in scrofula,) had been under a course of mercury for a venereal affection when the swelling came on; he rubbed it with a liniment composed of acetum scillae, but with no advantage: he was then directed the mezereon decoction, and soon recovered the motion and natural figure of the arm. The cure was completed in twelve days without any sensible effects from the medicine or the liniment, which he continued to use. A woman with enlarged lymphatic glands of the neck, which did not subside as usual with warm weather, I cured by mezereon. I gave it in the following manner: mezereon root, one ounce; water, six quarts; liquorice root, half an ounce. Boil down to four quarts. Half a pint to be taken twice a day, or as much as the stomach will bear. Sea-bathing seems to have the greatest specific power. In general it is used in summer; but the disease requires it most in winter. It is to be considered in two lights; first, as a simple bath; secondly, as to its specific quality. Baths are of three kinds: cold, warm, and tepid; the specific effect being the same, whatever may be the temperature. When other diseases attend scrofula, for which baths of certain temperatures would do harm, the sea-bath should be regulated accordingly. In some constitutions a different degree of warmth is suitable from what is suitable in others. In some cases two good purposes may be answered, for in some the cold and 360 HUNTER'S PRINCIPLES OF SURGERY. specific are both wanted, and in others the tepid and specific. The directions for sea-bathing are in general insufficient, but they should be particularly attended to, as with some the cold bath will disagree independently of all disease; some will be rendered cold all day by it, though they will recover by its specific effect, which is always the same in all constitutions. I do not think that the sea-bath lessens permanently the susceptibility to the disease, but that it is a temporary cure for the present diseased action, and prevents the effect of immediate exciting causes; but after leaving it off, the susceptibility returns, and the disease often returns in winter after a summer course of bathing. Next to sea-bathing and mezereon, hemlock seems to have the greatest specific power. Burnt sponge has been recommended, but I am in doubt of its specific powers Mineral alkali is serviceable, but its specific powers are very weak. Warm clothing, and that next the skin, is most proper, because it keeps the warmth constantly the same. This is Nature's method in the cure of animals, and it should be particularly attended to in children : the outward clothing may be according to people's fancy. Children of this disposition should never expose their naked feet to cold and wet, as is frequently the case. The exercise should be gentle, and the diet principally of a vegetable kind: but I consider this of little service, as the disease is frequent in those countries where little else but vegetable diet is eaten. From the indolence of scrofula we might a priori think that many local applications would be serviceable, especially those of a stimulating kind; but these all prove injurious, as mercury, copperas, balsams, &c.; indeed, few applications are of any service. I have myself only found benefit from cicuta and sea-water. The juice of hemlock made into a poultice is serviceable after suppuration has come on; and poultices made with sea-water have done good, when the cicuta has failed, especially in white swellings, before suppuration has taken place; and I may also mention that this water, as a lotion, applied to sores, often gives them a healing disposition. The best surgical treatment for those cases which will not admit of removal, is to do nothing. Where suppuration is superficial, openings into the abscess should not be made, as they are often absorbed spontaneously, and when they break of themselves they heal the soonest: but exceptions may arise, as when an opening is required to extract an exfoliated bone; otherwise openings only add to the causes which produce such diseases. Those parts which cannot be removed, as lumbar abscesses, are generally incurable; and the question i?. are they to be opened or not ? The only answer I can give is, that before opening them patients are generally pretty well, but immediately after opening them they become unhealthy and hectic, which continues till death. Hence the practice of opening them shortens life; but sometimes thev get well bv this practice, that is, perhaps, about one in a hundred: and it mav be thought right to treat all as if they were curable, as we cannot OF MORTIFICATION AND CARBUNCLE. 361 distinguish; this must be left to the surgeon and the particular circumstances of the case. The common effects of surgical treatment will not be found to arise in cases of scrofula; cutting always does harm. In common indolent abscesses, free openings is the best remedy, and the production of as much violence as we can; but this will not do in scrofula and cancer. In scrofula, irritable inflammation frequently supervenes, or erysipelas extending to the cellular membrane, and produce sloughing: for we find that no violence can increase the restorative action without also increasing the original disease. We find few actually die from the disease, although the vital parts are attacked. When the lungs are affected, it is the difficulty of the respiration which kills; when the mesenteric glands are affected, death happens from the want of nourishment; when there is lumbar abscess, the constitution is worn out by long-continued discharge and teazing complaints; but when superficial parts only are affected they generally get well. Accident produces many visible causes of cure, as fevers, &c.: and probably many invisible ones too. Climate is often a cure as well as a cause of the disease. Children are most favourably situated for a cure, from the daily variation of their constitutions. Puberty often produces a cure, wdiich may be called the natural, and is most manifest in women. When the disease begins at a later period it has not these resources, but is more tedious. CHAPTER XXII.

of mortification and carbuncle.

Mortification ;—death of parts;—accompanied by pain :—with or without inflammation ;—treatment.—Caustics and cauteries.—Carbuncle ;—peculiarity of situation;—often numerous;—attacks free livers;—appearance, progress;— constitutional and local treatment.

The effects of life are preservation and action : death is the loss of both. Life may exist in the whole, or only in a part; but it must always be in a vital part. Other parts may be dead, without affecting materially the machine. The immediate cause of death in a part would appear to be a loss of circulation: this may arise in various ways, but it must be the effect of some cause. Mortification is very different from universal death: the loss of natural life arises from some universal action having taken place, the same structure still remaining; but it is altered in mortified parts, all is blended in one mass of animal matter, and cannot possibly be injected. Partial Death, or Mortification, arises from various causes, yet 31 362 HUNTER'S PRINCIPLES OF SURGERY. there is probably in all of them some cause which may be called specific. There are many others which may be considered as immediate and remote causes, as happens in gout, which may be produced by many causes, yet the specific cause has a peculiar mode of action in this as it has in other diseases. Mortification is commonly attended with great pain, characterised by burning, and, if it is in view, the stagnation of blood in the vessels always produces a livid colour. The same burning sensation takes place from pressure, if carried sufficiently far to produce mortification, and is familiar in people's heels after lying long in bed. There are two kinds of mortification, one without the other with inflammation. The first arises from causes less visible than the other; that is. there is no increased action, or sensible heat, although the burning pain is considerable. What the predisponent cause is I cannot tell :* I have suspected something like a spasm of the small vessels, but I cannot be certain: we know spasms will sometimes threaten mortification, as we see in priapism, by which I have seen mortification produced in a dog. When the disposition is present, the action goes on ; as we see in sores, some parts being of a purplish hue, and going on in this way, while health is in the other parts. In some of these cases, a part withers and dies, and does not stimulate the living parts, so as to produce separation, for a long time; but I have seen too few of these cases to judge of them accurately. The second kind seems to arise from a change taking place before death. Inflammation seems to be the immediate cause; but this inflammation has two remote causes, of which one is weakness. which is the commonest cause of mortification ; but the other, or that which produces carbuncle, is not well known. Inflammation sometimes depends upon an increased action with increased power of the vessels ; but in mortification it must depend on an increased action with diminished power; in all cases where this kind of mortification takes place, we have evidently a deficiency of the animal powers. In young people, mortification is generally preceded by fever ; in old by debility ; and the weakest parts generally give way first, as the toes. But debility alone does not produce mortification, if there happens to be strength in the part sufficient for the action which is induced : debility, therefore, is only a predisposing cause. We see this in scarifying" anasarcous legs, in weakness from accident in weakened parts, in bruises, in frost-bitten parts, or wherever action is produced beyond what the powers of the part or system are able to sustain. But the increased action is not necessarily inflammation ^ it may be a salutary endeavour of the part to restore itself; which salutary action the powers of the part canmot support, and hence it gives way and dies. When frost-bitten parts are exposed to heat, the debility is

* [Later observations have rendered it highly probable that dry gangrene always depends on a more or less complete obliteration of the great vessels: either the arteries or veins, but particularly the latter.] OF MORTIFICATION AND CARBUNCLE. 363 increased by the necessary action, which action the strength of the part cannot bear. Heat is congenial to life ; but it should be proportioned to the degree of life, otherwise it will increase the debility. On this principle it is that cold air is so serviceable to people weakened by disease. In frost-bitten parts, for example, the living principle is much diminished by the previous cold, and heat must be gradually applied, in proportion to the quantity of life which remains ; but as the manifestations of life increase, so should the heat be increased also, otherwise by applying a degree of heat, at once, too great in proportion to the life, the part will mortify, which is invariably the case in man and all other animals; for warmth induces a more than ordinary exertion of the living powers, which may even be so considerable as to destroy the powers themselves. This proportion of power and action should be attended to in many common diseases: as appears from a case which I have already described. Parts which have been weakened seem much disposed to take on the continued sympathy; and the parts, finding this disposition, become irritable, and are easily inflamed, which inflammation produces death oftener than any specific inflammation. Mortification, however, is neither peculiar to weakened habits nor to accidents; but is often consequent on common inflammation, as in compound fractures. In a state of health the powers are much greater than the action ; but when this state does not exist, either the powers or the action must be predominant. Thus in mortification the powers are too weak for the action ; but this weakened power is produced by various causes, such as old age, accidents, or erysipelas. The skin of such as take on this irritable action is generally opake, and looks withered even in the young subject. Of the Cure.—If our principles are just, it will be easy to lay down a rational practice. Practitioners have been conscious of the predisposing cause, which is debility, but not of the immediate one, which is increased action. Hence bark, cordials, wine, &c, have been given, by which an artificial or temporary action has been excited; but this practice produces an increased action, without producing increased powers, and afterwards the debility is greater. Antiseptic substances have also been employed, such, for instance, as preserve dead flesh; but this is very absurd. The local treatment has been equally so: consisting in the application of warm dressings in the wounds made by scarifications; thus stimulating parts, the actions of which were already too violent. This practice might be suitable enough in the first kind of mortification, where death comes on without any increased action or effort. Will any thing lessen action, and increase also the power ? Wine will not; bark is the only remedy of this kind we have: other medicines may be given on this principle, but none of them are so efficacious; opium for instance is useful, from lessening the action, but it does not increase the strength: it is, as I have ascertained by experi- 364 HUNTER'S PRINCIPLES OF SURGERY. ment, more especially useful when applied to the part than when given internally. Of Caustics and Cauteries.—The death of a part may be produced by a deficiency or privation of the living principle, and is then called mortification; but it may also be produced by mechanical and chemical causes, as bruises, the actual cautery, or caustics. Too much action will also arise from a violent stimulus, as arsenic, and kill a part, and in proportion to the deficiency of the living principle, the sooner will death be induced: as happens in bruises, in which the cellular membrane sloughs before the skin, though the skin is the part which is most injured. The more vascular a part is the greater is the power of life; hence muscles, glands, skin, &c, difficultly part with their life; whilst bones and tendons soon die by exposure, from want of living power to support the necessary inflammation. The actual cautery coagulates the juices, in consequence of which the living principle cannot exist. When caustic alkali is combined with animal or vegetable substance, the compound forms a kind of soap which is soluble in water. The operation of a caustic is not immediately on the living principle, but chemical; but its effects are retarded in some measure by the living principle, so that it acts more rapidly on some parts than it does on others. As no substance acts chemically till in solution, the caustic must first be dissolved, which is slowly effected by the perspiration on the skin. By the application of a caustic, a blister is raised, and serum accumulated, which dissolves a greater quantity of the caustic ; and this effusion is the consequence of all irritations, and is intended to get rid of the cause of irritation. Alkalies are in many cases to be preferred, although from their ready solubility they are disused in some cases. Their action is so very expeditious that the presence of the surgeon is required: they ought, therefore, only to be used in superficial abscesses, as they give much pain and spread, and would take up too much of the surgeon's time when the parts to be destroyed are deeply seated. The caustic alkali, or lapis infernalis, should have its end wetted with water previously to its being applied to the living part; as soon as it is through the cuticle, the cutis effuses serum, which should not be allowed to extend beyond the intended slough, but should be wiped off writh an armed probe. It is impossible to say what time will be necessary for this effect, as it will depend on the thickness or depth of the part; but when a very long time is necessary, we may scarify the upper part so as to quicken its effects; and this I may observe is a very ready way of opening superficial abscesses, when near the skin. When we make an issue in this way, we should go as low as the cellular membrane. The common caustic consists of caustic alkali and quick lime, which should be mixed with soft soap, or with liquid caustic alkali, if its powers require to be increased ; the concentrated acids are likewise employed, as for example the vitriolic and nitric, which should be applied, like the caustic alkali, by means of a piece of glass, or OF MORTIFICATION AND CARBUNCLE. 365 some other substance which will not be acted upon. The metallic salts are chiefly employed to destroy luxuriant granulations, as blue vitriol, lunar caustic, &c.; but if they are used to produce a deep slough, they must be used in powder, mixed with some soft substance. These last substances only coagulate the parts, but do not chemically combine with them, as the alkalies do. Arsenic seems to have both a chemical and a poisonous effect upon the living textures. Now as most parts are capable of communicating their sensations to the brain, the gradual destruction which caustic occasions produces considerable pain. This may be alleviated by mixing opium, or extractum thebaicae with the caustic, or by the application of an opiate plaster an hour or two before the caustic, which will have a very good effect, especially in women and children who cannot well bear the caustic long enough to produce its proper effects without these alleviations.* A long while generally elapses before we can bring a cut issue to a proper degree of suppuration, as the means which are employed for keeping it open prevent a good suppuration, by keeping up inflammation; but caustic seems to answer better, by destroying a certain quantity of substance, which separates in the form of an eschar, and leaves an open sore that will generally suppurate freely. In some the eschar is slow in separating; in others it will be thrown off in about ten days; but in others it will require three weeks, the separation being always more rapid when the caustic goes fairly into the cellular membrane, which has less life than the cutis. The separation of a dead part from a living is performed by the absorbents, which take into the circulation the edges of the sound parts which adjoin to the dead, and thus the dead part being set at hberty drops off. But in order to effect this, inflammation is first produced, and then ulceration or absorption follows. The separation takes place sooner or later, in proportion to the life of the part; hence the skin, muscles, and parts which are nearest the heart, slough readily: tendons and bones slowly; and cellular membrane less readily than the skin. Life in a part is in proportion to the number of vessels it has for its simple support, the vessels for other purposes not adding to its powers of life, considered in itself. In new-formed parts, however, the separation is not so slow as in original parts, although they are disposed to slough more readily; but this depends on a different principle, viz. on weakness, which is consistent with what has been already observed. How far the brain is capable of sloughing I cannot determine, but I should imagine that people would never live long enough for this process to take place. In vegetables we find dead parts rot; but they are

* [Nothing is so effectual for alleviating the pain occasioned by potassa fu3a» as the application of common vinegar, which immediately combines with the alkali to form a neutral salt. It possesses also another advantage, in restraining the operation of the caustic, which in some instances is very apt to, spread beyond the assigned limits.] 31* 366 HUNTER'S PRINCIPLES OF SURGERY. not separated as the dead parts of animals, because they have no absorbents; but if they separate, they do so by a process of putrefaction. Soft parts, when about to slough, first become darker coloured, and if exposed to the air become dry and hard. The separation always begins at the external edge, forming a groove between the living and dead parts ; this groove becomes gradually deeper, till at last it is quite through, and the slough drops off. Why the separation should begin at the surface I do not know, except that the external parts are more ready to take the alarm, or that the skin goes through its operations and separates more rapidly than the cellular membrane; but as we find in bones that the exfoliation always begins at the external edges, I cannot offer the above as an explanation. Its beginning from the edge makes the separation at first only from the circumference, but sometimes it is from the centre, as when matter is formed underneath. The separation of which I have been treating is of two kinds; first, where the cause is constitutional, as in mortifications; secondly. where it is local, as by caustic. To the first kind of separation much attention is to be paid, as the mortifying disposition must cease before the part already mortified can be removed. When the separation is begun, if the parts are small, they may be allowed to go on their own way; but where it is a whole limb, it is necessary to remove it, as the length of time required for the separation would often wear out the patient's constitution. The when and the where this is to be done is a matter of great importance. We should certainly remove the bulk of the mortified limb ; but as there is danger of inflammation and fresh mortification being brought on, from cutting the living parts, even though the mortification should be stopped, from the constitution being mended, we must wait till we see a healthy line of separation, and, by the appearance of the granulations, judge of the propriety of amputation. I would recommend removing the part in mortifications of the leg, by cutting into the dead parts near to the living; and after a time, if it be necessary (which can only happen in the legs,) the irregularities can be removed. In sloughs from caustic, practitioners used to cut out the eschar ; but as a part remains which requires the same length of time to separate as the whole, nothing is gained by this proceeding. Carbuncle, or Anthrax, is an inflammation of a specific kind, which is shown by its regular termination. It may in some measure be reckoned a cutaneous disease, commonly beginning in the skin. The mortification which takes place in the parts succeeds inflammation ; yet it does not always arise from inflammation, attended with general debility ; nor does it always take place in the weakest parts, as the foot, but commonly near the source of circulation. That there is some peculiarity in the constitution, is perfectly evident, from the patient being apparently otherwise well, with a orood pulse. It seems to be a specific effect of this inflammation to produce death in the part. It most frequently appears on the back or OF MORTIFICATION AND CARBUNCLE. 367 the neck, and seldom in the fore part of the body, which is very singular. Carbuncles seldom come alone; but seldom more than one begins at the same time, but in succession: I have seen them extend over the whole back. Another peculiarity is, that they seldom attack any but those who have lived above par, especially in eating ; in which respect they resemble gout, as well as in the circumstance that they are generally inclined to occur in fat people. I suspect that any irritation, applied to those in whom there is this peculiarity of constitution, brings them on; therefore to an elderly man of this disposition I am cautious of applying blisters. The inflammation is in the cellular membrane, and though very similar to the erysipelatous, is yet very different. It does not produce adhesive inflammation, but runs into mortification, as the erysipelatous does; neither does it produce true suppuration. At first it appears like a pimple or small-pox pustule, in the cutis, the matter of which would seem to penetrate to the cellular membrane, and affect it; but perhaps the disease itself extends to the cellular membrane in the first place, although the first idea is most probable, as there is no adhesive inflammation to prevent that being the case. The tumefaction is considerable, but flat: the cells being filled with pus, mixed with coagulable lymph. The matter approaches to the skin by ulceration ; or if very tight, it mortifies. The matter oozes from several openings, like water out of a sponge. At last, in most cases, the cellular membrane dies, and the ulceration in the skin extends. Sometimes the whole sloughs off together, leaving a wide chasm, with inflamed lips. When suppuration takes place, there is continued sympathy in the surrounding contiguous parts, and then the inflammation becomes more of the adhesive kind. The local peculiarities are as follow: 1st, it begins like a pimple ; 2dly, the inflammation spreads a little, giving it the appearance of a boil; 3dly, the inflammation spreads under the skin, and a doughiness takes place, the skin itself not being much affected, the tumour having a defined edge, and being six or seven inches perhaps in diameter. The skin now becomes affected, beginning at the first point of the disease, and spreading throughout; little pimples are frequently formed upon it, which often communicate with the cellular membrane beneath. Bounds are at last set to it by the surrounding adhesive inflammation. The practice should be to open it as soon as it begins to form a base, to prevent its spreading further. When it has gone through all its stages the process of cure begins, and it heals as soon as other sores, and one is often healing while others are forming. Boils, I suspect, are all of the carbuncular species, but less in size, with more of the adhesive inflammation, which prevents their spreading. Boils have another distinction, which is, that they seldom produce suppuration equal to their inflammation ; and, as in carbuncle, there is produced a visible slough, so there is a core in boils which answers to the slough. When boils are very large the constitution is in fault, but not so when few and small; they are 368 HUNTERS PRINCIPLES OF SURGERY. then supposed to be salutary. Boils arc most frequent in youth, carbuncles in age ; yet we find boils in old people; but carbuncles are seldom in people below the middle age. Treatment of Carbuncle.—As carbuncles begin with a species of inflammation, which terminates in mortification, the patient being generally of a full habit and in apparent health, it might be asked if the constitution should not be treated by evacuants. I would treat it always according to circumstances; but in the latter stage I have always found evacuations improper. Evacuations never answer in constitutional specific inflammations, as they do in common inflammations. Bleeding in gout and erysipelas is often very injurious, yet it is occasionally necessary ; neither in inflammation from poisons has it a good effect, unless where the constitution is ready to run into violent common inflammation, in addition to that produced by the specific power of the poison; hence, in small-pox, gonorrhoea, &c, bleeding is sometimes useful: but evacuations and bleeding never agree so well with those who have lived above par as in the temperate; hence they are more useful in acute rheumatism than in acute gout. Cordials and bark, and warm medicines, are commonly given, and made more stimulating by the addition of tinctures; and these are given for two reasons; first, because the part is dead ; and secondly, because the patient often becomes much debilitated. But such medicines can only keep up the strength and the action depending upon strength, but cannot overcome the specific nature of the disease: therefore we should give others, that we may at last find out a specific; yet, if we had a specific, these remedies would be often also necessary, as they are in lues. I have, however, tried other means, but with little success. A gentleman, aetat. 70, who had lived well, and had had a universal dropsy, which he appeared to be cured of, was attacked with inflammation on the left shoulder, which turned out to be true carbuncle, which, as soon as it was opened, was followed by several more near the spot. The person under whose care he was gave him one drachm of powder of bark with ten drops of tinct. thebaica every hour, which rather purged him; he also took calomel and opium, the former of which was increased, to see if mercury would do good; but it had no effect; neither did it prevent more from forming. One was very large, and there were several smaller ones in different parts of the back; one was opened pretty early, which seemed to stop its increase, and I opened another at its orifice, with caustic, which discharged the matter, and seemed to stop its progress. The first during this time was healing. When the first appeared he seemed to be in good health, but afterwards he gradually lost it, his appetite became bad, his pulse quick and small, and his ankles a little swelled. As neither bark nor calomel and opium had been of any use, I said to Dr. David Pitcairn, " Now do not let us permit this patient to be lost, whilst we are only using such means as experience shows to be of little or no effect; let us try something new ; OF MORTIFICATION AND CARBUNCLE. 369 for David, this is a case more belonging to my province than yours, and I, being an older man, have seen more of them than you have, and can tell you what perhaps you did not know, that we have no powers in this case that are known." Now David is a truly sensible man, and not governed by form ; he therefore agreed, but wanted to know where we were to begin. " Why, with the first letter of the alphabet, and go through the catalogue of the materia medica, so as we do not stop too long on the letter B (Bark), as is generally done." As cicuta was a medicine of considerable powers, and then not thoroughly known, we began with that, of which the patient took half a drachm in the day, but without effect. I then tried sarsaparilla, both in powder and decoction; the powder was made into bread and pudding, to eat through the day, but with no good effect. Dr. Pitcairn now proposed decoction of elm bark, from having seen it of use in erysipelatous inflammation, there appearing an affinity between this disease and erysipelas ; this I assented to, but from a thought which had struck me, I wished to try the fossil caustic alkali (soda); so they were given together, and we thought they were of service, as it was during this course that the patient recovered, though it must be confessed it was very slowly; but some fresh ones which had shown themselves disappeared again. I have given fossil alkali to several since with good effect. I was myself always troubled with boils, until I took forty drops of this lixivium night and morning in milk for two months, when all my boils disappeared, and I have since had no return of them. Another gentleman asked my advice on whom two or three carbuncles had begun to appear, and he was perfectly cured by this treatment. The topical treatment consists in the free dilatation of the skin which covers the sloughing cellular membrane ; but as this comes after all the mischief is done, I think it a bad practice at the latter stage, although applications to the part are useless until the slough is separated. Small openings at the beginning, to prevent the increase, is all we should do, and not make any openings afterwards.*

* [The practice of modern surgeons is to make free openings in all stages of the disease, for which the best reasons may be given. An escape is thus afforded to the diseased sloughs and secretions, and an opportunity given to apply appropriate dressings to the sore; but the propriety of this treatment chiefly arises from the indisposition of the skin to ulcerate sufficiently extensive to allow the sloughs to come out. See note, p. 196.] 370 HUNTER'S PRINCIPLES OF SURGERY. CHAPTER XXIII.

General considerations respecting poisons;—definition of a poison.—Mineral poisons.—Animal poisons, natural and morbid.—Morbid poisons ;—their origin ;—effects local, constitutional, or mixed.—Of local diseases.—Itch ;— nature;—cure.—Cancer, definition of;—origin and progress;—effects only local;—does not affect the constitution ;—reasons for this opinion ;—extension of the disease by three modes;—absorption of the poison;—does not produce specific fever;—no proof of poisonous disease of the constitution.— Local effects of cancer ;—predisposing causes.—First appearance and symptoms of cancer ;—progress towards suppuration ;—treatment;—destruction of cancer;—extirpation;—mode of effecting it, and cautions to be observed.— Cancerous testicle.—Fungated sores.—So-called cancer of the penis.

No unexceptionable definition of a poison can be absolutely given, for almost everything capable of injuring in a healthy or unhealthy state may be considered as a poison. They are such as destroy either the structure or the functions of an animal. The last may be similar to the weather, which often affects the mind, and may be called a poison of the mind. But there are many substances which, when applied to a healthy state of the body, may injure, as poisons; yet when applied to an unhealthy state they will counteract that state, and keep up health as long as they have the power of irritation. The healthy action, then, being a tertium quid of the unhealthy and poisonous, these are to be considered as medicines which have different effects at different times, and under different circumstances, as food; sometimes they are capable of curing one diseased state and not another, even of the same specific disease; indeed, each disease has its own peculiar specific. Many substances act as poisons in some constitutions and not in others; as muscles, &c, thrown into some stomachs poison them ; also strawberries and cider in some persons cause flushing and erysipelatous inflammation. Whatever our idea of a poison may be, we must generally exclude the idea of quantity, for even the most innocent substances may become poisonous by quantity, as common food. Some cannot eat meat of any kind without being affected, but can eat fish or fowl without harm. If we do not pay regard to quantity we cannot distinguish poisons from medicines, as many of our medicines may even be given so as to poison or to produce no effect at all. So vague are our ideas of poison that we do not give the name of poison to all the actions of the same substance when it is formed to act in two different ways, though it may kill in both ways. A man killed by swallowing a piece of glass could not be said to be killed by a poison, because we know its effects; but powdered glass swallowed would irritate the coats of the stomach, OF POISONS. 371 and kill, and would hence be called a poison. Many other things might be called poisons, as cold water drunk when a person is hot, producing fever, erysipelatous inflammation, the eruption called a surfeit, &c. Poison is not only what is taken in by the stomach, but also by the lungs, as mephitic air, which kills immediately, and has no cure; so likewise many applications administered externally are called poison. Our present idea is that they act in three ways, viz. mechanically, chemically, or on the living principle. The two first always act locally, but the third either on the whole or on a part. We do not call everything a poison which acts mechanically, as swallowing a knife ; but we suspect a different mode of action from powdered glass or hair, and therefore call them mechanical poisons, imputing the effects to some hidden power, which is in some measure right, it being their irritating effects on the living principle of the coats of the stomach, not simply cutting and lacerating mechanically as the knife does. These ought not therefore properly to be called mechanical poisons. Melted lead or boiling water will kill chemically, yet cannot properly be said to be poisons. Some only irritate the part, the substance being too weak to have any chemical effect. Nor is everything which acts on the living principle to be called a poison; but we should distinguish between poisons of this kind and medicines; yet we find " a slow poison" is a common saying, as brandy. Arsenic kills by inflaming the stomach, and not by a peculiar action, therefore it is not a poison; nor is anything else which kills by common inflammation or common effects. I would define poison to be a substance which has a peculiar mode of irritating, a peculiar mode of affecting the living principle, and which produces its effects more or less in any quantity, however small. Of this kind are most of the morbid poisons ; but small-pox falls short of the definition, in not keeping up its effects after having once affected the same person. Of the different ways in which Animals may be affected by Poisons,—There are three ways of their acting, and also a mixed way. The first is where the poison affects only the part in contact with it, and no part of the general system, except from the local injury. This includes the three kinds of poison, viz. mechanical, chemical, and those acting on the living principle. Examples of these are glass acting mechanically, sublimate of mercury acting chemically, and the matter of cancer, which acts only on the living principle. The second is when the poison affects the constitution, which constitutes it a morbid poison entirely, as, for instance, the jail distemper; but how it gets to the constitution is unknown. The third is when the whole nervous system is affected, as by poisoned arrows, honey, muscles, nux vomica, and probably also the bite of a mad dog, which produces no visible effects on the injured part. The mixed, or compound, is of two kinds: first, when it produces inflammation of the part, as was observed of cancer and itch, and at the same time affects the whole constitution, as the venereal dis- 372 HUNTER'S PRINCIPLES OF SURGERY. ease, which the cancer and itch do not. The second is that which has three different modes of contaminating a part, like the third class, viz. 1st, locally, as in the itch; 2d, like the jail fever, which acts first on the constitution; and 3d, like the first of the compound, producing local inflammation; of this kind is the small-pox, &c. We might make a fourth out of those in which the poison might be taken into the constitution without producing local effects in the first place, as in jail fever, natural small-pox, &c.; but these are then received by contact, and not by insertion. In some the constitution is unaffected till ulceration has taken place, from knowing which we can often prevent their general effects. How a poison lies inactive so long is with difficulty explained, but it is a principle belonging to each, each having also its own specific latent period before it affects the constitution. Mineral Poisons.—The mineral poisons are mostly metals, the poisonous qualities of which depend on their solution in our juices ; their virulence is often increased by their combination with acids, as, for instance, mercury with the muriatic acid; but they can poison either by affecting the living power, or by acting chemically; chemically when strong, and by irritating when diluted. Minerals are capable of acting in the three different ways; when mechanically, it might be supposed to be by altering the composition or arrangement of the animal fibre, so as to injure without destroying the living principle: but such cannot properly be called poisons. They may act chemically by combining with animal substances, as the vitriolic and other acids, and caustics. When they act on the living principle without seeming to alter the part to which they are applied, they are probably absorbed, and excite universal irritation, as for instance, lead and mercury, which, when given too largely, seem to have this property; but each of these will kill by their action on the stomach. I know of no mineral poison that produces universal sympathy when locally applied, except it is applied to the stomach. Most of them produce peculiar complaints as we see from lead, mercury, arsenic, opium, &c. The Vegetable Poisons appear to be of three kinds; first, the natural juice of plants without having undergone any secretion; secondly, the secretions of plants, as honey and the essential oils; thirdly, those which have undergone a change by a chemical process, as the oil of tobacco. These produce their effects in two different ways, similar to the mineral, viz. chemically, and on the living principle. Their power on the living principle is much more extensive than that of the mineral, and their effects are peculiar and different from those of any other disease, so that they are generally well characterized. The Animal Poisons act principally on the living principle. Nothing shows the variety of animal matter more than the poisons. The blood may be considered as the fluid animal, because it contains all the parts which compose the animal, and the whole body is composed out of it. The solids which exist already must have OF POISONS. 373 the power of decomposing this fluid according to the stimulus of each part, and on that the natural and morbid secretions depend. I shall consider these under the heads of natural and morbid poisons. 1st, Natural Poisons.—Many of these first affect the stomach, as some kinds of fish; others consist of animal secretions, which are produced by particularly formed organs, provided with an appropriate apparatus and ducts, for the especial purpose of secreting and inserting the poison in the bodies of other animals. These secretions do not affect the parts which contain them, although they would probably poison the animal itself if inserted into any other parts than those which naturally contain them, as, for instance, in scorpions, which poison each other, although the Abb6 Fontana denies this as to the viper. The second species produce their effects in two ways, by contact or by insertion. Those which affect the skin by simple touch are various, as sea insects, the ant, &c.; but before the others can possibly operate they must be conveyed into a wound, which brings them to the living principle, on which they will always act under these circumstances, but not when the cuticle is entire; hence all these animals make a wound before they can act. This second species are all of them very active, producing immediate effects, both locally and constitutionally, otherwise they would not answer their intended purpose, which is the defence of the animal. According to the quantity, they would appear to be more or less violent in their effects, as in small animals the effect is the same in kind, but not in degree, as in a large one; thus a large one kills, while a small one does not; the rattlesnake being longer and larger than the common viper, kills much sooner. Those which poison by the touch, first produce a soreness, and some swelling and inflammation, which latter is of the adhesive kind, although the swelling is generally oedematous. Those which act externally and locally do not occasion swelling at any distance, so that the continued sympathy is not great, as that from the ant. These all appear to have their peculiar distance, unless the effects are increased by rubbing, itching being generally their consequence. Those which become constitutional have also local effects, which, however, are not so fixed as those from the other sort; for in these a kind of continued sympathy exists, and a dissolution of the parts comes on, which produces extravasation of blood, and consequently a dark colour. The first symptom is pain, and if the poison is absorbed there is also a sore red streak, extending to the lymphatic glands, situated between the injured parts and the thoracic duct. The glands also, which are principally in the bend of the great joints, swell, and become painful, showing either absorption of the poison or that the lymphatic system sympathizes. A cold fit often follows, and sometimes convulsions and death in a short time. The injured parts likewise swell, and become dark and livid, from vessels carrying red blood which did not originally do so ; but the continuance of the local effects does not arise from the constitution, otherwise 32 374 HUNTER'S PRINCIPLES OF SURGERY.

similar effects would manifest themselves in other parts of the body. Suppuration of the part to which the poison is applied rarely happens : but by absorption this may sometimes happen, as in common buboes. Effects such as we have been describing are seen in the viper, scorpion, &c. Some insects poison in the act of sucking their food, as the gnat and bug, and these seem to produce specific diseases; that is, they appear not to suck the common red blood from the vessels, but to produce an inflammation, and afterwards suck the extravasated blood from the inflammation which they have occasioned. 2d, Of Morbid Poisons.—These probably arise from a diseased state of the body or part, which originated either spontaneously, or from the application of similar matter from another animal. This is proved by the late origin of all of them. We have many daily arising spontaneously, and which continue their excitement. The cancer is a proof of this, and I once thought the same of hydrophobia ; but Mr. Meynell tells me he never had a hound mad but what had been bitten. Some of the morbid poisons are lost, and others are losing ground every day for want of frequent communications : some of these act in a fluid state, and others in a state of vapour. The venereal poison requires contact, and possesses itself of those parts which are most frequently in contact; some affect the secretions so as to make them poisonous, as the saliva in the mad dog. It may perhaps in time happen that the human race shall be extirpated by poisons alone; but it is more probable that many poisons are extirpated, and that new ones arise in their stead every day. Morbid poisons differ from the natural in requiring a morbid action in the body to produce them, as cancer, which is either the produce of a similar disease, or arises spontaneously. These produce greater variety of effects than the natural, some of which are local, and others both local and constitutional. Some affect the whole system rapidly, as the variolous matter; but not so the venereal. Many of them are not content with simply poisoning those people wfio come within their influence, but communicate it to others, who in their turn are capable of affecting others. Every part of the body is more or less susceptible of being poisoned. The effects of some poisons seem confined to peculiar animals; as cancer, which occurs only in the human species. Others affect various animals; as hydrophobia, which attacks horses, cows, dogs, cats, geese, fowls, &c, when they are bit. Others only affect animals of the same species, as the variola. Some appear to choose peculiar ages; as the cancer, which never occurs in young people. Many choose a peculiar sex, or peculiar parts only are affected by them, some parts being more susceptible of some actions than others: as, for instance, the breast, of cancer; the skin, of small-pox; and the salivary glands, of hydrophobia. Both the great and small effects of morbid poisons depend less on quantity than those of the natural do. Some poisons perform their own cure, as in those cases where the constitution is only capable of being affected OF POISONS. 375 by them once; which, as we have no artificial cure, is a happy circumstance. But others seldom or never affect the system in such a manner as to oblige it to discharge the poison. Some perform their own cure, when the mode of their action is on a peculiar part, as gonorrhoea. Of the Modes of receiving Morbid Poisons.—If morbid poisons are applied in a solid state, they must become fluid, by the moisture of the part, before they can act. The manner of receiving them and being affected by them is in three ways : 1st, when the effects are always local and never reach the constitution, as in cancer; 2d, when the constitution only is affected, as in jail distemper; the 3d, or compound, is when the poison can affect one only or both at the same time, as the lues and small-pox. The first is of two kinds: first, when the patient contracts a poisonous disease, either from known causes, or from violence committed on parts which are capable of running into diseased action, and of communicating the same to others, as cancer and lues ; the second is where the disorder is external and local, so as to affect only the cutis, as the itch. The manner of receiving the second, or entirely constitutional, may be either by effluvia or contact. The first, or that by effluvia, is owing to the air being impregnated with poisonous vapours arising from the animal body; but how the poison is received into the constitution is unknown, there being no traces of it before it shows itself by the fever, as in the jail distemper and hooping-cough. The second of this division of constitutional poisons is the plague, which is caught by contact; but whether it could or could not be produced by inoculation is unascertained. The mode of receiving the third, or compound kind, is twofold: first, it differs from merely local poisons, because it seldom acts locally at first, as the variola; tor we receive this disease naturally without knowing it until the constitution is affected. Secondly, it can affect both the constitution and the part, as the above; but generally there is local inflammation, and sometimes ulceration, previously to the constitution being affected, as in lues. . . Of the Itch.—This is one of our first class ot the first division ot morbid poisons, which affect by simple contact and are always confined to the parts to which they are applied. Scabies never affect the constitution ; from which I conclude that it is never absorbed. However it originated, it is now become a common noison It produces small ulcerations, which are generally much confined; but when the disease is of long standing they are as large as a sixpence, and covered with a scab. First there is a smaU vesicle, which discharges a kind of matter, which gradually thickens until genuine suppuration takes place; *e matter wbch is thus formed produces ulcers of the same specific kind although its powers of contaminating are evidently weak, as c eanhness prevents contamination. The irritation of it ^scarcely sufficient to produce inflammation, and continued sympathy hardly evei takes place in it. It gives no pain, but occasions a sense of itching, it 376 HUNTER'S PRINCIPLES OF SURGERY. is generally caught by shaking hands, or from lying together, as the lower orders of people commonly do, who are most subject to this disease. Uncleanliness aids this effect; therefore washing the hands, even after the matter is on them, prevents the disease from taking place. When it arises from lying in an infected bed, or from a nurse, it is generally communicated to every part of the body; a fact which gave rise to an opinion that its origin was derived from nastiness. The disease has been said to arise from animalculas ; but these, if present, are, I am sure, unnecessary for the existence of the disease, as I have often examined the matter and found no animals in it; yet they may sometimes be in the matter. I forget who was telling me lately that Dr. Teigh had shown them to be, not in the pustule, but in the skin near it, as little black specks. It is capable of affecting the cutis when covered by cuticle, but not where the cuticle is thick. It affects parts thinly covered with cuticle most, as between the fingers, but often no part escapes, making the cure very troublesome ; for as the cure is effected by local applications, it then becomes necessary that they should be extended over every part of the body. Although a specific disease and a poison, yet it has several cures, which act in various ways ; but all must have powers to remove the irritation of the disease. Mercury often cures and often fails; yet a girdle often will cure when the unguent will not. Solution of sublimate of mercury sometimes cures, as does a decoction of hellebore. A sulphureous unguent is most efficacious; but it is volatilized by the heat of the body, and is disagreeable. If mixed with water, the smell is somewhat prevented; but it is then less efficacious. Sulphur given internally reaches the skin, and produces a smell thereupon, and will then cure ; but to produce this effect it must be given so largely that it is apt to prove purgative: opium therefore should be conjoined with it. Sulphur, however, is the only certain remedy ; and when properly used, it may be depended on. Of Cancer.—The diseases commonly classed under this name are in appearance very different, and probably are very different in their nature; they should not, therefore, be called by the same name. I would call that cancer which produces the following effects; viz., a circumscribed tumefaction with much hardness, and a drawing in of the skin covering it, as if the cellular membrane underneath was destroyed: then a species of suppuration takes place in the centre, and ulceration of the external surface. This is its most frequent appearance. It most commonly attacks the conglomerate glands, and first the female breast; also the uterus, the lips, the external nose, the pancreas, and the pylorus; besides which the testicle is very subject to it, though that is not to be classed among the conglomerate glands. So that when I speak of cancer, I mean a peculiar disease in some of the above parts. There is another disease which is also called cancer, which I have called fungated ulcer. The frequency of a disease in any one part is apt OF POISONS. 377 to lead us to suspect that this one disease is peculiar to that particular part; but scrofula attacks these parts also, in the form of a tumour, and a distinction between them would be a great advantage, although this probably can only be made in the breast, which is subject to both diseases. When small, they probably cannot be distinguished ; but as they increase, the distinction is more easy. If cancer, it will vary its appearance by becoming less circumscribed, not having so determined an outline, from the cellular membrane around becoming diseased ; the skin will be less moveable, the nipple more or less retracted, and the lymphatic glands going to the axilla will swell. But in scrofula there will be no surrounding disease, no affection of the nipple or axillary glands, no adhesion, even though the tumour be large; I have seen one loose, when it weighed eighteen pounds; the veins become also enlarged. When scrofulous tumours are large, and become slightly inflamed, they get more diffused, and put on a greater resemblance to cancer ; but in cancer the inflammation comes on earlier, and goes on with the disease. In cancer, the surrounding parts that are affected by continued sympathy also become cancerous near the skin, that is, all the parts become blended in one mass ; but in scrofula, although the surrounding parts are in action, yet that action is not so scrofulous as the part itself; so that the skin will sometimes heal over the scrofulous tumour, as I have seen in the testicle when suppuration had taken place, by which I determined the disease was no cancerous. The tumefaction is from interstitial extravasation of coagulable lymph, and the tumour is more ready to inflame than in the scrofula. Cancer is one of the first class of our first division of poisons, viz. that which only produces local effects, though it has been supposed to contaminate the constitution; which would be terrible indeed, as we have no specific nor even a palliative for it. The reasons for this opinion are the following. When a cancerous tumour has been removed often, the sore does not heal, or breaks out again. Sometimes it breaks out again in another part of the body ; which has been thought a proof of its arising from the constitution. This last circumstance as often arises where there has been no operation as where there has been one ; it does not therefore depend on that circumstance as a cause. However, the operation having or not having been performed does not affect their argument, unless they could prove that cancer is an act of the constitution, and acts as a drain or concentration of the cancerous poison, and that by stopping this it must go somewhere else. But the proportion of those who have it break out in two different parts of the body, compared with those who have it only in one, is about half what'the latter bear to those who have not the disease at all, or about five hundred to one. I never saw it in two different parts of the same person; but I have seen it in more than two distinct points of the same part. It often arises in distinct points of the same breast, but seldom at the same period; and some of these 32* 378 HUNTER'S PRINCIPLES OF SURGERY. may be so much in their infancy when the operation is performed as not to be observable, but afterwards increase and require a second operation. The surrounding substance of the breast has often little tumours, sometimes containing a blackish fluid; these may be called cancerous hydatids. It is therefore best to extirpate the breast completely at once, to remove the whole complaint. It must further be proved that the continuance of the disease, or contamination of other parts, is not owing to the healing or not healing of the sores. The above reasons for believing it constitutional would satisfy any one not of the profession; but for surgeons to be influenced by them shows an ignorance of the first principles of the animal economy. They should recollect that though it affects the neighbouring parts, and the parts through which the poison passes, by sympathy, producing a similar disease, it does not affect distant parts, like those which really affect the constitution. A scirrhus or cancer appears to have three modes of contaminating: 1st, by continued sympathy, which is common to other diseases; 2dly, by remote sympathy, which is peculiar to itself; 3dly, by contact or communication of p its matter to other parts by contamination. I have called these consequent cancers, in opposition to the original. Absorption would appear to arise during both stages of the disease : first, by the absorption of the tumor in a scirrhous state, that is, the coagulable lymph, which possesses the cancerous property; secondly, by the absorption of matter produced by suppuration. Both appear capable of contaminating the absorbents through which they pass, and so far agree with local morbid poisons ; but it may be a compound poison, so as to affect other parts, as small-pox does. Whether it is a compound poison I will leave you to judge from the following remarks on the effects of poisons on the constitution. Whether a poison be a compound one or enti ely constitutional, it first produces a fever that is universal, a specific general irritation ; and, if compound, local irritation also, which local irritation produces a discharge, as in small-pox and measles, the discharge being similar to the original in these, but not so in the venereal disease. Let us now see how far cancer agrees with these: if it does agree, it must be a compound; if it does not, it must be entirely local. A cancer in the breast or testicle is similar to the inflammation and ulceration after inoculation, or to a chancre, only differing in specific properties. The matter of lues and variola may be absorbed and cause inflammation of the absorbents, and the cancerous matter is also capable of absorption and of contaminating the parts as it goes along, so as to form buboes, or what I call consequent cancers; so far therefore these diseases are similar. But the above diseases are very quick in their effects, while the cancer is very slow : and so far their cases are dissimilar. The variolous poison occasions fever and an eruption similar to the original one; but the venereal poison does not do this, its effects being merely OF POISONS. 379 local, consisting of blotches on the skin, &c.; neither does the cancerous poison when in the constitution produce fever, nor is there any local effect which arises strictly from the constitution. Does cancer then produce any effect on the constitution ? When it has existed a long time we find slight fever and hectic ; but this is no more than the effect of all long continued irritations, or sores which are not disposed to heal, but no peculiar effect is produced from this affection on the constitution. The effect which has been mentioned is produced even by the venereal poison when of long standing, but it is different from the specific. I have seen locked jaw and difficult respiration produced from a cancer in the breast; but these were occasioned by the irritation of a non-healing sore; small-pox does not produce this hectic. It has been said that cancers are produced by ill health, as rheumatisms are; but this arises from the age of cancer being the age of such complaints, and being thus the predisposing cause of both, but not particularly of the cancerous disposition. Let us compare the cure of cancer with that of the venereal disease, when the latter can be extirpated externally. If we remove entirely a chancre, the sore heals readily and does not return, and if this is done before any absorption has taken place, then there will no future disease; but if after absorption has taken place, and after a bubo has formed, then, although the sore will heal, the bubo will go on, and the constitution will be affected. So likewise, if we remove a cancer, and no absorption has taken place, the sore will heal and the constitution will not suffer; but then the whole must be removed, as in the local venereal disease, otherwise it will return. If removed, and there has been absorption, the parts heal, though the consequent cancer goes on; but if the whole cancerous parts are removed, the constitution is free; here it differs from Ihe venereal; for there, when absorption has taken place, sores break out in other parts, but this is not the case in cancer. The general opinion has been the reverse of this. This shows that a cure is the consequence of a total removal of the parts, notwithstanding absorption has taken place, if all the diseased parts are removed. The only powers of contamination of this poison are; 1st, when it spreads from the centre, thus producing a disposition to the disease in the surrounding parts, and an extravasation of interstitial matter; 2d, when the disease extends to distant parts, as when little tumours form under the skin at some distance, not in the line of absorbents; and 3d, when it produces the same disease in the absorbents and glands. This last is easily conceived, from its being a poison; but the affection of a part that seems to have no connexion whatever with the diseased part is not so easily accounted for. When scirrhus is entirely let alone, it is commonly very slow. A small lump in the breast may sometimes continue for many years : but whenever inflammation takes place, its progress is accelerated, in as much as inflammation is an increased action of 380 HUNTER'S PRINCIPLES OF SURGERY. the part itself, as well as of the surrounding parts; so that if we remove the tumour in this condition the glands in the breast will probably inflame and sometimes suppurate, although often these effects are not cancerous. When inflamed, the tumour increases very fast, but the sympathy is very slow, which is common in many diseases. When distant parts, not in the line of the absorbents, are affected, it would appear that such parts are very slow in taking on the diseased action, although the disposition has been formed, for we frequently see that they do not take on an active form for some years after. In those cases where there is absorption of coagulable lymph, it becomes a question whether the lymph is cancerous, or whether the affection is only sympathetic; most probably it is the last. The last two forms of the disease are generally very slow, which circumstance makes them dangerous, as it cannot be ascertained when parts are really affected with the disease, which often necessitates a second operation, it being necessary to remove all the parts which have undergone the disposition, although the inflammation or tumour itself is circumscribed. The predisposing Causes of Cancer are three in number, viz. age, parts, and hereditary disposition; perhaps climate also has considerable effect, though not itself a predisposing cause. The cancerous age is from forty to sixty in both sexes, though it mayoccur sooner or later in certain cases. The testicle for instance, often becomes cancerous at twenty or thirty; but then not from the disposition of the parts alone, but from accident.* Cancer has been supposed to be in young people's eyes; therefore it is most probable that the breast is less subject to it at this age, and other parts are not so much confined to age in this disease. We often see tumours in the breast at thirty, and probably some of them are cancerous, although scrofula is more to be suspected. When cancer occurs in the breast of women under forty, it is more rapid in its progress than when the patient is older, and also more extensive; remote sympathy likewise takes place more readily in them than in the old, so that the operation succeeds better in the latter on this account. However, we seldom find it in the young or very old; although of the two it is most frequent in the latter. When it occurs in the young, does it not show a very strong disposition for the disease, and therefore more danger, from a greater likelihood of its returning? The parts most disposed to Cancer are those peculiar to the sexes, as the breasts and uterus in women and the testicles in men. Can-

* [The distinction between the various forms of medullary disease and cancer was not well understood in the time of Hunter, and consequently he has classed together several diseases which modern pathologists have very properly separated. It is unquestionably true that cancer may exhibit itself before the age of forty, and fungus haematodes after that period ; still, as a general rule this does not happen, nor is there any individual fact more characteristic of the difference of these diseases than the different periods of life at which they respectively occur.] OF POISONS. 381 cers are more frequent in women than in men, in the proportion of three to two ; owing, perhaps, to the more frequent changes taking place in these parts in the former. It is that change which renders them unfit for conception and changes the whole system, which is particularly obnoxious. Thus, the three disposing causes are : 1st, a peculiar part; 2d, the age of the patient; and 3d, the peculiarities of the part at this age. The parts next in order and frequency, and which are common to both sexes, are the conglomerate glands about the lips, nose, throat, tongue, pancreas, stomach, especially the pylorus; intestines, especially the rectum. Besides these, we have it in the eyes and glans penis. The disease also appears in other parts of the body; but, as most other parts are similar in structure, it does not attack one more than another. It sometimes falls on the bones from contamination, but on no one in particular. Whether Hereditary—Some suppose cancers to be hereditary; but this I can only admit according to my principles of hereditary right; that is, supposing a person to possess a strong disposition or susceptibility for a particular disease, the children may also; but I have not yet ascertained the generality of this fact. In many persons it would appear that some of the predisposing causes are sufficient to become the immediate ones ; as when the diseased action takes place at a certain stated time, without any immediate cause. Are they more frequent in one country than another? I have heard they are very rare in the West Indies; and they do not seem to be frequent in the Friendly Islands, where the women fight for prizes, and aim chiefly at the breast; so, most probably, climate has some power, both in disposing to the disease and in preventing it. Symptoms.—On the first appearance of a cancer it is a hard tumour, and being specific it is circumscribed, having its specific distance, when it is called scirrhus, which is a cancer not yet ulcerated. Sometimes the first symptoms of a cancer in the breast is a bleeding from the nipple, which must come from the ducts of the lactiferous tubes; and this I have seen in men. In the testicle it sometimes begins by forming a hard knot, but is generally more universal. When in the lip, there is a thickening of some part of it, and this increases till ulceration takes place: it comes on similarly in the nose. -There is one peculiarity in cancers, which is, that when the skin is affected there is a wrinkling or tucking in of it, which appearance always leads to suspicion of cancer. It often begins in the antrum, and distends the whole face; but I rather suspect this to be of the fungated kind. In the bones it begins by a soft swelling, which I also suspect to be fungated, from its forming such luxuriant fungoid granulations when ulcerated. In the testicle sometimes a softness and even an obscure fluctuation may be felt, although I suspect this not to be cancerous. The pain at first is so trifling as scarcely to be noticed; but when there is a disposition to suppuration and ulceration, a shooting lancinating pain is felt, and also a dead heavy one, which pain increases more in propor- 382 HUNTER'S PRINCIPLES OF SURGERY. lion than the disease appears to do. It is more violent in some parts than in others, depending in some degree on the sensibility of the part; thus, it is more violent in the breast and testicle than in less sensible parts. Cancer, however, produces no symptoms peculiar to itself; they are only such as would arise from any injury to the part capable of producing the above effects, independently of any specific quality. Cancer of the lip, of the nose, or of any other part, will produce no peculiar symptoms; but in the testicle, symptoms peculiar to that part will be occasioned, as, for example, pain in the loins and sickness, with suppression of the secretion of semen; in the bladder, the symptoms will be like those of stone; in the rectum, purging and tenesmus ; in the stomach, sickness and vomiting; within the skull, headache and coma. Cancer appears to give rise to no constitutional symptoms, except such as would arise in other diseases from the long-continued wearing pain and perpetual discharge. The progress towards suppuration is of two kinds: one by external ulceration, the other by the scirrhus becoming encysted. The first happens when the tumour reaches the skin and affects that part with disease, when the skin first becomes shining and then ulcerates and forms a sore which is called a cancer. While this is taking place, inflammation is beginning from internal exposure, and the exposure increases the inflammation. The other mode depends on a change in the substance of the tumour itself akin to suppuration, but which is very different from any other kind of suppuration. The cavity contains a fluid, which fluid appears of various kinds, and in some cases begins very early. In some breasts, where such an encysted tumour has been removed, many small knots are found during the operation, by either cutting through or against them : they often suppurate without any inflammation, therefore there is seldom any inflammation until there has first been exposure, When the matter has been evacuated, common inflammation and suppuration take place, and the disease then proceeds rapidly. Cancerous matter may be reckoned of two kinds: first, that in the tumour, which is various; in some serum, in some blood, and in others coagulable lymph, or else a yellow curdly matter. The second is of a bad quality, and proceeds from the internal cavity, which is similar in all respects to that formed externally by ulceration. The fluid from a cancerous ulcer is most commonly of a purplish red, which makes the skin of that colour; the absorption here seems to be of the intermediate substance between the skin and cyst. When near to the skin, it inflames and ulcerates as in other ulcerations. Of the Treatment.—No cure has yet been found ; for what I call a cure is an alteration of the disposition and the effect of that disposition, and not the destruction of the cancerous parts. But as we have no such medicine, we are often obliged to remove cancerous parts; which extirpation, however, will often cure as well as we could do by changing the disposition and action. Arsenic OF POISONS, 383 seems to have some power of this kind, and its effects might be increased, by being used internally and externally; but its use is very dangerous, and I am afraid insufficient for the disease. This is a remedy which enters into the empirical nostrums which are in vogne for curing cancer ; and among which Plunkett's holds the highest rank. But this is no new discovery, for Sennertus, who lived the Lord knows how long ago, mentions a Roderigues and Flusius, who obtained considerable fame and fortune by such a composition. I was desired to meet Mr. Plunkett, to decide on the propriety of using his medicine in a particular case : I have no objection to meet anybody : it was the young one; the old one is dead, and might have died himself of a cancer for aught I know. I asked him what he intended to do with his medicine. He said, " To cure the patient." " Let we know what you mean by that : do you mean to alter the diseased state of the parts ? or do you mean by your medicine to remove the parts diseased 1" " I mean to destroy them," he replied. " Well then, that is nothing more than I or any other surgeon can do with less pain to the patient." Poor Woollett the engraver died under one of these cancer-curers; he was under my care when this person took him in hand. He had been a life-guardsman, I think, and had got a never-failing receipt. I continued to call on Woollett as a friend, and received great accounts of the good effects; upon hearing which, I said, if the man would give me leave to watch regularly the appearance of the cancer, and see myself the good effects, and should be satisfied of its curing only that cancer, (mind, not by destroying it,) I would exert all my power to make him the richest man in the kingdom. But he would have nothing to do with me, and tortured poor Woollett for some time; till at last I heard the sound testicle was gone, and at length he died. Arsenic may be given internally with safety. If applied externally to a large surface, it will often affect the constitution, though to a small one it may be safe and efficacious; as, for example, a grain of arsenic to four ounces of water, applied in a poultice twice a day; this will often destroy the cancerous disposition and render the sore more healthv. Sometimes the quantity of arsenic must be increased, and when'it gets better, less must be used. When the cancerous disposition is too strong to be removed by this means, we must destroy the parts; and for this there are two modes: 1st, by destroying the life of it; 2dly, by an operation. The destruction of all the cancerous parts is the intention in both: in destroying locally any specific disease which has the power of its own increase, the whole must be destroyed. That first method I divide into two: 1st, the power which life has of destroying itself, by producing an action it cannot support; 2dly, by chemical effects. The second method is by an operation ; but the first method is not so extensive as the second, for with the knife we can go where the other cannot reach ; so that the first can only be employed where tne disease is exposed and circumscribed. When lying on a nerve or artery, the deadening method has the recommendation of safety. 384 HUNTER'S PRINCIPLES OF SURGERY. The first mode produces too much action, as would appear from the effect of arsenic, which does not act chemically, but produces inflammation, and probably weakness also; so that the diseased parts will be destroyed by it, while the sound parts will remain alive ; and this makes it preferable to caustic, which is not only too violent, but deadens the sound parts as well as the unsound. Plunkett's medicine is made as follows : crowsfoot, 3 drachms and 2 scruples ; dogfennel dried, 1 drachm ; crude sulphur, 2 drachms and a half; white arsenic, 5 drachms: beat in a mortar, and form into a powder; one or two drachms of which are to be mixed with the yolk of an egg, and being spread on a piece of bladder to be applied so as to cover the sore.* Arsenic alone would produce too violent an inflammation, and destroy the sound parts by mortification. The second, or chemical mode, is by caustics, by which life is destroyed by the combination of the caustic with the parts it comes in contact with, making but little distinction between those which are sound and those which are unsound ; but these cannot be used very extensively, for obvious reasons. The Second mode, on' Extirpation.—In considering the propriety of this we must often be more careful than in the above modes; and as the knife may be extended further, so the diseases may be more complicated than in the other modes. We should first consider if the whole disease can be safely extirpated, and if so, the operation is proper. Some cannot be extirpated safely, as when in the extremities ; but in such cases the whole limb may be safely removed, which should in doubtful cases always be done. But sometimes in the breast it is so fixed to the ribs as not to be entirely removeable. Now to know if a cancer is proper for operation, two things should be considered, viz. the cancer itself, and its consequences. Great attention should be paid to the tumour, whether it is moveable or not; for as the disease is further extended, so the parts are more united to the tumour. If it reaches a part which cannot be removed as the hips, or parts which cannot wholly be removed by amputation, then nothing can be done; but if the tumour is not only moveable, but the part naturally so, then there is no impropriety in removing it, with regard to the tumour itself; but before removing it, or a limb, we must consider if there are any consequences. We should examine for example, the glands in the groin or axilla to ascertain if they are thickened or swoln, and also the course of the absorbents; for if these are sound and moveable, then the disease may be safely removed. But if any are so deep or fixed as not to admit of removal, then we must consider whether the whole limb can be removed, above the consequent tumours; and if not, we ought to do nothing. All the above circumstances being considered, and no objections existing, the breast may be safely removed; and if any consequent cancers easy of extirpation are found, they

* [Any preparation containing so much arsenic must be exceedingly unsafe and dangerous.] OF POISONS. 385 may be safely removed also. But it requires very great caution to know if any of these consequent tumours are within proper reach, for we are apt to be deceived in regard to the lymphatic glands, which often appear moveable, when, on extirpation, a chain of them is found to run far beyond out of our reach, which renders the operation unsuccessful. As this is not easily known, I would, in most cases, where the lymphatic glands are considerably enlarged, advise that the case should be let alone. We cannot be too nice in our examination, nor often too rough-handed in the operation. In cases where the original and consequent tumours are circumscribed, and sufficiently moveable, the operation has generally been successful, being nothing more than a common wound. But the parts may have acquired the diseased action, and thus render the operation unsuccessful, although that action was invisible. Whenever there are such appearances the parts should beremoved as soon as possible : on the contrary, when the disease-has not beem entirely removed by the knife, from its not having been carried into the sound parts, the operation is unsuccessful; and these^arethe circumstances which gave the idea of the disease being constitutional: but let us observe what part of the sore does- not heal, and what part breaks out again after the operation. This is either in the cicatrix, or, in the lymphatic glands. Now, if the whole disease is not removed,.,the sore either does not heal, or if it does, the cicatrix breaks out again ; so likewise, if the surrounding contaminated parts are not removed, although the whole original disease is, then, some months after, there will be a new ulceration there; and so with regard to the glands also, if any of these are so far diseased as to require extirpation, but too high up for the knife. I have sometimes seen, after the operation, the glands under the clavicle swell, and push out the clavicle on the lower part of the neck; it has also happened, that after removing the glands in the axilla the absorbents between them and the original disease have become contaminated, in which case they should be removed as soon as possible. The contamination extends in other instances on the inside of the sternum, in the course of the internal mammary artery. Sometimes these consequent cancers appear long after the operation, even years, when they should be immediately removed. After the visible disease is removed, we should minutely examine the sore, so as to feel and press every part, and if any thing is hard or irregular, remove it. After operation in the axilla, we should introduce the finger into it, in order to discover if any of the other glands are affected; and before-the part is dressed the tumour itself should be inspected, to see if there are any corresponding appearances, so as to lead to the supposition of a part being left; but this can only be done in those from the breast, those only being- circumscribed. Having once had the. misfortune to leave a part, I let it go on for a few days, when the sore granulated healthily all over, except at that part, which had a blueish appearance, and discharged a dark coloured matter. I then dissected that bit only, and the patient 33 386 HUNTERS PRINCIPLES OF SURGERY. recovered. If a contaminated part is left, it comes into action in a few months after the operation; and if two or more are left, they all appear about the same time, and should be removed if they can as soon as possible, before they have contaminated other parts, when, in general, it will succeed, as far as I have seen. If these are not removed, other parts will be contaminated, and kill in the end ; but if parts contaminated do not come into action at the same time, after the original is removed, we shall not succeed. It is surprising to see how a young man, if he catches an idea which has any novelty, will write away on it and tell you wonders. Thus, Mr. Fearen has lately recommended healing by the first intention in this disease, which is the last thing to be thought of, as we have here only in view the total removal of the disease, and not the healing of the wounds. But no man should write a book without taking every circumstance of the disease into consideration; he should not write from a single idea, which many circumstances may render futile. I have used this plan in small circumscribed cases in the breast, where there was very much skin, although I have been very liberal of my removal at the same time. Of the effects of Cancer in ihe Breast when incurable.—When the glands become indurated the fluids are not absorbed, in consequence of which there is a stagnation and extravasation of serum, causing oedema of the parts around. The arm, and the integuments of the chest below, swell, and the fingers are sometimes rendered immoveable, and very painful. The inflammation about the diseased parts spreads, and causes a tightness around, which occasions dyspnoea, and in this stage sympathetic cancerous tumours often arise at a distance, and hectb fever comes on. We must now give large doses of opium, which yet do not often relieve the pain. I have seen the oedema of the arm before there was any tumefaction of the lymphatic glands ; but when oedema occurs, which is not the consequence of absorption, there may nevertheless be afterwards hardness of the glands from this cause: however, the oedema above mentioned puzzled me, having never before seen it without the glands being enlarged, and I have never seen another case. Of the Cancerous Testicle.—The same observations are here applicable as in the breast, with respect to the propriety or impropriety of an operation. If the cord is thickened the operation is doubtful, the consequence going often further than at first appears. If it has not extended so high as the ring, I would advise extirpation, it being the only resource left. When the testicle has affected the scrotum there may be absorption to the glands of the groin, as in lues; of this I have seen one case, where, half a year after the operation for the removal of the testicle and scrotum, the glands in the groin ulcerated, and killed the patient. In this case the testicle had become adherent to the scrotum. I cannot say how far it would have been proper to have removed these glands at first, but from the adhesion the scrotum was necessarily removed. I was at OF POISONS.] 387 first puzzled to account for the appearance of cancer in the groin, as we know the testicle receives its vessels, &c, from the loins, and therefore the glands in the loins become affected by the disease extending along the course of the cord; but when I recollected that the scrotum was affected, I knew it to be owing to the lymphatics of the scrotum, which pass through the groin. In cancerous diseases the surrounding parts become contaminated, and these again contaminate others ; but in scrofulous suppuration the surrounding parts, although affected, are not scrofulous, because this is not a poisonous disease. Before suppuration breaks out we can form little idea of the state of the part as to its malignancy: but after it breaks out we can, for if healthy it will recover itself, and granulate healthily; but if the contrary, it will not; hence, in the suppuration of the testicle, we cannot say whether it is scrofulous or cancerous till it is ulcerated, when the mode of healing informs us of the disease. Of Cancer of the Lip.—If small, the operation for the hare lip should be preferred, and it is right in this case to have the cure in view as soon as the operation is done, although we should be sure to remove the whole disease. These principles attended to will be sufficient to guide us in the management of cancers in other parts of the body. Of Fungated Sores.—These are commonly called cancers, and are similar to them in being incurable, although they differ in other respects. The cancer eats, as it were, away parts, though there is still an increase of growth or tumefaction; but in fungated sores there is a spongy fungus which cannot be kept down. It is, in fact, a specific well-marked disease, which appears common to every part, which I believe the cancer is not. I have seen it in the antrum, the tibia, the eye, the testicle, and the rectum. Its beginning, I believe, is in the form of a tumour, both of the encysted and solid kind; for I have seen an encysted tumour opened which threw out this fungus, which is very soft, spongy, and pulpy, of a dirty black colour, very easily torn, and very apt to bleed : the matter does not seem to be poisonous, for the glands and absorbents never appear to be diseased by it. Here [exhibiting it] is a preparation to show the disease on the sole of the foot, and here another, of the tunica vaginalis in which the fungus was very extensive, as was also this fungus on the penis. A woman had a large one on the upper part of the foot, for which I amputated the leg, and in this case the glands in the groin were not affected, and she recovered, which fhows there was no poison to contaminate by absorption. A man had a swelled testicle, which was not very painful, and the cord was not affected, which led me to think that it was scrofulous; the scrotum became affected by local sympathy, and adhered to the testicle. I removed the testicle, but not entirely the adhering skin, and after some time a fungus arose from the skin, and his health became impaired by the repeated hemorrhage. I tried arsenic made intoTocSs with flour, which were stuck into the fungus but stall hese did not destroy it sufficiently, and the man afterwards died. 388 HUNTER'S PRINCIPLES OF SURGERY. If this had been cancerous the progress would have been different, for the skin would have become cancerous from contamination, and the cord would probably have been affected in the same way. On dissection of this fungus from the cicatrix of the old skin the glands above were found sound. This species of fungus is pretty regular in structure; it is striated, and radiated, and its external surface is larger than that of the surface of contact. Nothing is left for it but to remove it, no natural cure being known ; but we should be careful to remove the whole of the diseased parts that have the disposition, as they will otherwise soon take on the action. It kills without appearing to have done much mischief, whereas cancer does much local mischief, and so do the consequent ones, before death. The first case of fungated ulcer from accident which I ever saw was one from a blow on the arm, which was afterwards obliged to be amputated. Cancerous Diseases of the Penis are somewhat similar to the former, consisting of a fungus, which begins on the glans, and increases till the whole becomes an excrescence, which resembles the fungated sore when cut or torn, except that it is much slower in its progress: sometimes it attains a large size, and appears like a cauliflower; and sometimes it is in the form of a tumour, covered with skin, and ulcerated at some parts only. These tumours may, I think, be classed with the true tumours, which consist of a newformed substance; but I do not think they ever arise from the venereal disease, as has been supposed. Extirpation, in my judgment, is the only surgical resource; and if so, it should be done as early and as effectually as possible. The Hcematocele Specifica Testis takes its name from the nature of the contents, which are blood, serum, or often a firm coagulated blood, the extravasation arising from a diseased action, or a peculiar mode of secretion, and not immediately from accident, as is the case with one species, which leads me to call this haematocele specifica testis. It is often taken for a eancerous testicle, and removed for such, and the fluid blood is then mistaken for cancerous extravasation, though it is common extravasated blood in the tunica vaginalis; although I will not deny that there may be new cysts occasionally found that may contain blood, as other new cysts do matter. Those which I have seen have felt like an obscure hydrocele, or something between hydrocele and scirrhus testicle. (See note, p. 232.) As it is so uncertain what is the true case, I have always advised tapping in the first place. In some there is much serum, and this in the centre of the coagulum, which adheres to the sides of the sac, the whole feeling like a thickened sac; and often the sac is really much thickened. In some the testicle has been so pressed as to burst, and to fill the cavity of the tunica vaginalis; but whether this is a specific disease or not, or a cancer similar to that in the breast, I do not know. I rather think it is specific, but if not specific, the treatment of hydrocele would be proper; but it must be distinguished from sarcoeele, as in that a different treatment is necessary. But we find OF POISONS. 389 it will not admit of the same cure as hydrocele. The coagulum adhering to the sac keeps off the stimulus of imperfection, and prevents a cure, so that in many cases it would be perhaps best to dissect out the whole tunica vaginalis. Perhaps in some the blood may become part of the solids, by becoming vascular, as was shown in a preparation. A gentleman in China had, he thought, a swelled testicle, for which he used mercurial ointment. On coming to England, I could not determine the case, but rather thought it a hydrocele. I tapped him; but no fluid was discharged, although the lancet was pushed in an inch deep. Mr. Pott was called in, who thought.it a scirrhus testicle, and the operation was performed. On examining it, a bloody serum was found in it, and the coats of the sac (which was the tunica vaginalis,) were extremely thick, and the testicle was much squeezed by it. I should think it was a mixed case, and might have been cured as hydrocele; but am not certain. In a case of true haematocele there was first an uneasy sensation, and the testicle was painful to the touch afterwards; the swelling increased, and was mistaken by a surgeon for hydrocele; then the hardness increased, and the pain become acute; several punctures were now made, which brought on much inflammation, which required that an opening should be made, in order to examine the parts, which were found to consist of grumous blood and a thickened coat. It was advised that all should be removed, together with some of the skin: but I think not enough, for although the parts healed readily, yet some months afterwards a swelling in the abdomen reappeared, and destroyed him. On dissection, there was found a set of tumours extending to the diaphragm, on the epiploon, together with some others in the liver, respecting which it was a question whether they were scrofulous or cancerous ; they went along the loins, in the course of the absorbents, showing them to be cancerous; but the tumours in the epiploon, which is a part not in the course of the absorbents, staggered me in that opinion, and other circumstances puzzled me still further. At present I know not where to class this disease, but I find it has not the powers of recovery when put in the way of it by exposure. 33* ANALYTICAL TABLE OF CONTENTS SURGICAL LECTURES. CHAP. I.—Introduction.

Introductory remarks ...... 7 Fundamental principles of physiology the only guides to a just practice ....... 8 Mr. Hunter's opinion of operations . ... 9 Preliminary observations on matter, attraction, repulsion, &c. . 11 Of animal and vegetable matter . . . . .13 Distinguished from common matter by its peculiar properties, as growth, propagation of the species, &c. . . .14 Errors of the mechanical and chemical physiologists . .16 The living principle is the main thing to be taken into account in this investigation . . . . . .17 The subject will be elucidated by a reference to comparative anatomy, disease, and monstrosities . . . .18

Difficulty of conceiving of this principle . . . .19 Complex in its effects, although simple in its essence . . 20 May possibly arise from a peculiar arrangement of the ultimate particles . . . . . . . ib. Erroneous comparison of life to mechanical powers . .21 Action not an essential property of life .... ib. Vitality of an egg . . . . . .22 This illustrated by experiments . . . . . ib. Yet action, when once established, continues life at the same time that it exhausts it . . . • .23 Peculiar form of putrefaction in certain bodies . . . 24

Erroneous views on this subject . . .. . . 26 Animalization and vivification two distinct steps in the conversion of foreign matter into part of a living body . . 27 The blood not merely fluid animal matter . . . ib. But has also become vivified . . . . . 28 Coagulation, and its importance in determining the nature of this fluid ....... 30 Of the varieties of this phenomenon . . • .31 392 HUNTER'S PRINCIPLES OF SURGERY. Page Case proving the life of the blood . • • .33 The death of blood prevents coagulation . . • .34 The analogy between muscular action and coagulation . . 35

CHAP. IV.—General Views of Organization and Action.

The compounding of an animal body is according to certain established laws . . . • • .37 Of the sense in which the term organization is used . . ib. Organization and life are distinct from each other . . 38 An animal differs from a machine inasmuch as every part of the former is endued with independent action and vitality . ib. Of the different kinds of action and their mutual dependence . ib. Of elasticity . . . . . . .41 Conclusion . . .. . . . . ib.

CHAP. V.—Of the Functions of Nutrition and Absorption.

The Stomach Is the peculiar and essential part of all animals . .42 Is intimately connected with the other vital and internal organs 43 In which respect it may be compared with the sympathy of^the brain with externnl parts . . . . ib. Sympathy of this organ with tendinous parts and with the mind ib. Vascular System. Its action necessary to be understood . . . . ib. ^Of the arteries, veins, and absorbents . . . 44, 45 Relative offices of these three systems of vessels . . 45 Of absorption, and its different kinds . . . .46 Modelling absorption illustrated by the growth of bones . 47 Absorption of entire parts . . . . .48 Of the various uses of absorption . . . .49 Of the attempts to explain this process . . .51 Absorption induces an alteration in the matters absorbed . 52 Table of absorption . . ,. . . . ib.

CHAP. VI.—Of the Brain and Nerves, and of Sleep.

Passive and active states of the brain, giving rise to sensations and mind . . . . . . .53 Too much influence attributed to the brain in the bodily actions . 54 Of the action of the nerves, and of the senses . . .55 Sensation, and the laws by which it1 is regulated . . .57 Connexion between the different functions of the brain .. . 58 Of sleep, and its importance in the animal economy . . '59

CHAP. VII.—Of Susceptieility of Impressions; of Stimuli; of Dispositions of the Body ; of Habit and Custom.

Difference between impressions on animate and inanimate bodies . 61 Of stimuli, and the laws by which they are governed . . 62 Of dispositions of the body . . . . .63 Of dispositions of the mind compared with those of the body . 65 ANALYTICAL CONTENTS. 393 And of both with the action of machines Those parts which are most distant from the sources of power are the weakest ...... Of habit and custom, and the laws to which they are subject Particularly of the diminution of passive impressions by repetition, in proportion as the active power is increased Page 65

69 CHAP. VIII.—Of the Heat of Animals.

Heat is one of the first principles of action in nature Of the sensation of heat ..... The order in which the different functions cease when heat is withdrawn . . . . . Of the causes of animal heat .... Cases in which this function was remarkably deranged Experiments ...... Diminution of heat during sleep .... Experiments on hedgehogs .... Heat of the lower animals varies with the external temperature Standard heat of the higher animals not uniform . Resistance to external heat, and experiments Difference in the capability of different animals to generate heat On climate ...... CHAP. IX.—^General Principles of Disease.

Disease the consequence of some unnatural impression Diseased actions often established on the same principles as healthy actions ...... Obscurity of the physiology of disease . Difference of susceptibility in different individuals Susceptibility of constitution and of parts for different actions Universal susceptibility producing local diseases . Temperament ...... Of the disposition for restoration, of necessity, and of disease Disease consists in a disposition for wrong action, but not in the aetion itself ...... First symptoms of disease .... Disease from too great and from too little action Diseased actions always simple, so that two diseases cannot exist in the same part at the same time Of wrong actions, as spasms, locked jaw, &c. Of irritability ......

Sympathy may be regarded as a secondary principle, introduced into the economy of the higher order of animals Connexion of principles of action in the living body Sympathy between different bodies . Of natural or diseased sympathy, and division of the subject 105 106 108 ib. 394 HUNTER'S PRINCIPLES OF SURGERY. Inflammatory and hectic fever are examples of constitutional sympathy ..... Certain parts sympathize more strongly than others Of similar and dissimilar sympathies Sympathy between the body and mind And of the mind with the living principle Uses of sympathy in the animal economy Of delusion, and the manner in which it may be explainer. Delirium ...... Dreams ...... Animal magnetism ....

CHAP. XI.—Of Local and Constitutional Diseases.

Difficulty of distinguishing local from constitutional diseases Diseases are constitutional, local, or mixed Of common and specific diseases Of the effects of age, climate, seasons, temperature, and the moon, on disease ..... The humoral doctrines examined Experiments of injecting medicines into the blood Which produced no specific diseases Of hereditary diseases, and in what sense they are to be considered so Scrofula and gout, with reference to this principle Of the effects of the mind on disease Of symptoms, local and universal But to judge of symptoms, the general character of the patient should be previously ascertained

CHAP. XII.—General Principles of Inflammation.

Frequency and nature of inflammation In a healthy constitution it has three terminations, viz. Adhesion ...... Suppuration, and ...... Ulceration ...... Causes of inflammation ..... Comparative susceptibility of parts to inflammation Strength and weakness of the constitution and of the part affected modify the inflammatory process Effects of inflammation on the constitution And on the vascular system in particular . Inflammation of vital and of non-vital parts Effects on the constitution different according to the stage of the inflammation ..... Rigors and exacerbations ..... Of the state of the blood in inflammation . Colour, heat, swelling, and pain .... Of the resolution of inflammation Of the restoration of injured parts Of ecchymosis ...... Puge ANALYTICAL CONTENTS. 395 Of external wounds, and the method of Nature in healing them Further observations on adhesive inflammation

CHAP. XIII.—Of Adhesive Inflammation.

Inflammation a restorative action . . . • Of adhesive inflammation, and the causes which limit its extension Of the utility or final intention of inflammation . The extravasated lymph is always of the same nature as the parts which produce it Local symptoms, viz. redness, swelling, and pain Of the uses of adhesive inflammation . . . • Adhesive inflammation sometimes imperfect Of the resolution of inflammation . . • ■ First, by constitutional means, as low diet, medicines and bleeding, and ....... Secondly, by external applications . Of revulsion and counter-irritation . • • Treatment of adhesive inflammation when suppuration must take place .....•• Page 171 172 173 174 175

ib. CHAP. XIV.—Of Suppurative and Ulcerative Inflammation ; Granulation, Skinning, Hectic Fever, and Dissolution. Of suppuration, and the circumstances under which it occurs Does not arise from the access of air, nor from the violence of the inflammation simply considered But most frequently on the surfaces of mucous canals Symptoms of suppuration Treatment of suppuration Of suppuration without inflammation Of granulation and cicatrization Theories respecting the formation of pus Of the globular natuie of this fluid, and the modes by which it may be distinguished from mucus The quality of pus varies under different circumstances The final intention of this secretion Of interstitial and progressive absorption, together with the and immediate causes of these actions Of the relaxation of the skin over abscesses Progressive absorption always attacks those parts which are nearest the skin . Absorption may take place without ulceration Of ulceration . • • • Newly-formed parts are most subject to ulceration Granulations may be produced without any breach of the Of the nature of granulations . • Of the union of granulations by inosculation Granulations have less powers, and arc shorter-lived than parts • • • • Contraction of granulations, followed by cicatrization remote solids original 187

205 ib. 396 HUNTER'S PRINCIPLES OF SURGERY. Of tho formation of new skin, and the economy of Nature in this process ....... Of the nature of the new-formed cutis, cuticle, and rete mucosum Constitutional.effects of suppuration .... Hectic fever ....... Arises from a disease which the constitution cannot overcome But is sometimes an idiopathic disease .... Symptoms of hectic fever ..... Erroneous-opinions respecting the cause of hectic fever Hectic fever is not produced by large abscesses until they are opened Treatment of hectic fever ...... Of dissolution, or death, arising from excessive suppuration, independently of hectic fever ..... 206 207 ib. ib. 208 ib. ib. 209 210 ib.

ib. CHAP. XV.—Practical Illustrations of the preceding Subjects. Of ruptured tendons, and particularly of the tendo-Achillis Principles of treatment ..... Muscular exertion impossible until the injury is repaired . Of simple fractures ..... Of compound fractures, and of the manner in which compound fractures may become simple, and e converso Inflammation, suppuration, and ulceration of circumscribed cavities Pleuritis ..... Empyema and hydrothorax Of the treatment of these cases . Pericarditis .... Emphysema from fractured ribs, and treatment Peritonitis, common and puerperal Peritonitis after paracentesis Hernia ..... Caesarian operation Wounds into the cavities of joints Ganglions ..... Inflammation of the eye . Inflammation of the brain Inflammation of veins Inflammation of arteries . 211 212 214 ib.

216 ib. ib. 217 218 219 ib. 220 221 222 ib. 223 224 ib. 225 ib. 227 CHAP. XVI.—Of Hydrocele, and the Actions of Medicines. Theory of the cure simple, but the operation often fails Description of the disease, and its different varieties Disappears in children, but rarely in adults Diagnosis .... Situation of the testicle varies in different cases And also of the vessels . Of the palliative cure The proper feeling of the organ will often enable the surgeon to distinguish a hydrocele from a pulpy testicle 227 228 230 ib. 232 233 234

235 ANALYTICAL CONTENTS. 397 Page The sac sometimes suppurates after the simple evacuation of its contents ....... 236 Of the radical cure . . . . . . ib. A distinction to be made between operations of convenience and operations of necessity ..... 237 Observations on the different modes of radical cure . . 238 Which failed from ignorance of the true principles of cure . 239 The causes of failure common to the following methods, viz. . 241 Seton, tent, and caustic ...... 242 Of the mode of performing these operations . . • 243 Of the method recommended, viz. by incision . . • 244 Of the action of medicines ..... 247 Medicines destroy the action, but canuot destroy the disposition to disease . ... . . . . 249 In the restoration of action, as after drowning, the strength and action should be well proportioned to each other . . 250 Of the effects of external applications .... 251 Of pressure, friction, heat, cold, and electricity . . . 252 Of diseased dispositions and actions .... 253 nstances in which the action destroys the disposition . . ib. Some parts have a greater disposition to heal than others . . 254 Of the effects of age in this respect .... 255 One disease often cures another . . . . . ib. Of the uniformity of Nature's operations in the recovery from disease ....... 256

CHAP. XVII.—Injuries of the Head.

Of the different kinds of injuries of the head from external violence, viz. concussion, compression, wounds of the brain, want of due compression, and inflammation . . • 256 Concussion ....... 258 General observations on fractures of the skull . . • 259 Compression ....••• 260 Wounds of the brain ...... 262 The external table may be fractured without the internal, and e converso ..••••• *63 Of the propriety of trepanning in the above mentioned cases . ib. The operation described . . . • • 264 Of wounds of the dura mater, and their consequences . . 264 Hernia cerebri ...•••• *"• Of the principles of treatment in injuries of the head . . 265

CHAP. XVIII.—Of the Diseases of the Bones and Joints ; of Fractures, Dislocations, &c.

Bones liable to all the diseases of soft parts . . • 267 Death of bone, and caries ..... 268 Diseased actions of bone ...-•• 269 Ulceration and induration of bone . . j Of simple fractures, and the mode in which union is accomplished 270 Treatment of simple fractures . . • • .271 34 398 HUNTER'S PRINCIPLES OF SURGERY. False joints ...... Bones subject to the adhesive, suppurative, and ulcerative inflamtion ..... Compound fractures, and their treatment . Compound fractures communicating with joints Question of amputation considered Fracture of the patella, olecranon, and outer ankle Periostitis .... Spina ventosa .... Necrosis ..... Of the contraction of diseased joints Sprains . . . . . Dislocations .... New joints produced in consequence of dislocations Inflammation of joints, and the reason of their great danger Of lose substances in the joints . Of the different kinds of anchylosis Wasting of the muscles in consequence of diseases of the joints Exfoliation of bone . . . . Necrosis ...... Of the extraction of exfoliated bone Rickets . Mollities ossium ..... Of the effects of mechanical pressure on riekety bones Exostosis ...... Of the exfoliation of cartilage Page 273 CHAP. XIX.—Of Hemorrhages and Aneurism.

Hemorrhage ...... May arise from 1 st, natural eauses ; 2d, disease; 3d, violence Of the effects of loss of blood on the system . Of the efforts of Nature to suppress hemorrhage Of lateral wounds of arteries . Of the artificial means of stopping hemorrhage Of secondary hemorrhage Aneurism ..... Classification of aneurisms and definition of the term Causes of aneurism ...... Experiments to illustrate this part of the subject Action of the heart not the only cause of aneurism Although arteries are apt to yield most on that side where the force of the heart is greatest, ami where they are least supported ..... Opinions of Pott and Bromfield on the operation for aneurism The operation should be performed as early as possible Of those arteries which admit the operation General observations on the operation . Cases . . . . • . Notice of the first case in which the author operated by taking up the artery in the middle of the thigh 310 312 313 814 ib. 315

316 ANALYTICAL CONTENTS. 399 CHAP. XX.—Of Specific Diseases, Tumors, Hydatids, and Tetanus. P Of ulcers, and the causes which retard their cure Of abscesses, and particularly of those which are deep-seated Of Specific Diseases, or rather of those dispositions and actions which are not productive of restorative actions These may be divided into the irritable Producing irritable inflammation And indolent Producing hypertrophy of parts Varicose veins Corns Chilbains Preternatural accumulations of fat Elephantiasis ...... Of the enlargement of particular organs Observations on the cure of indolent dispositions in diseases Of the suppuration of indolent parts. Of Tumors Wens Tubercles Warts Polypi Tumors in the cellular membrane Of the removal of tumors .... Tumors in bones ..... Encysted tumors, the cysts of which are, 1st, natural; 2d, acquired ...... Of Hydatids of the uterus, kidneys, liver, lungs, brain, &c. Encysted tumors of the cutis .... Of inflammation, suppuration, and ulceration of new-formed parts Of fistula? in general ..... Fistula laehrymalis ..... Fistula of the parotid duct .... Fistula in ano ...... Fistula in perineo ..... Of the cure of fistula? Of the attention necessary in diseased joints respecting motion Tetanus ..•••*• Of the classification of this disease Causes ...«••• Constitutions most susceptible of tetanus . Of the climate and kind of wound which have the greatest influence in producing this disease Of the mode of attack . Treatment generally unsuccessful

Scrofula a specific disease without a morbid poison . • 351 Other animals besides the human subject liable to it • • »>. Some parts, constitutions, and ages more subject to it than others . ib. 400 HUNTER'S PRINCIPLES OF SURGERY. Page Scrofula not hereditary ..... Of climate and seasons in reference to this disease Susceptibility to scrofula may be acquired Progress of scrofula slow, and suppuration imperfect The different appearances of scrofulous tumours and sores Diseases of the hip .... Lumbar abscess ...... White swelling ...... Phthisis pulmonalis ..... Scrofula of the testicle ..... Scrofula of the breast ..... Of the medical treatment of scrofula Of the surgical treatment of scrofula

CHAP. XXII.—Of Mortification and Carbuncle. Mortification of two kinds, one with, and the other without, inflammation ....... 361 In the former case it arises from the action being too great for the power ....... 362 Of the principles of treatment ..... 363 Of death from caustics and cauteries .... 364 Of the separation of the dead from the living parts . .365 Carbuncle ....... 366 Depends on some peculiarity of constitution distinct from mere weakness ....... 367 The appearance and progress of carbuncle described . . ib. Boils . . . . . . . ib. Treatment of carbuncle ...... 368 CHAP. XXIII.—Of Poisons. General considerations respecting poisons . 370 Of the different ways in which animals may be affected by poisons 371 Mineral poisons ....... 372 Vegetable poisons ib. .... C first, natural . Animal poisons: \second% morbid 373 374 Of the mode in which morbid poisons are receivec I 375 Scabies .... ib Cancer .... . 376 Does not affect the constitution 377 Extension of the disease by three modes . 379 Predisposing causes 380 Of the parts most susceptible of cancer ib. Whether hereditary, and in what sense . 381 Symptoms . ib. Progress towards suppuration . 382 Treatment ib. Extirpation . 384 Cancer of the testicle 386 Fungated sores . 387 Cancer of the penis . 388 Haematocele .... ib. the end. PLATES

THE PRINCIPLES OF SURGERY. PLATES TO HUNTER'S PRINCIPLES OF SURGERY. ii PLATE I. Fig. 1. Fig. 2. Fig.i 3. mm PLATES TO HUNTER'S PRINCIPLES OF SURGERY. ill Fig. 1. PLATE II. Fig. 2. - ' • ; PLATES TO HUNTER'S PRINCIPLES OF SURGERY. IV Fig. 1. D A PLATE III. Fig. 3. Fig. 4. \ STANDARD WORKS ON ANATOMY, MEDICINE, SURGERY,

&it& tfj* (Collateral Ztimtts,

ED. BARRINGTON & GEO. D. HASWELL,

MEDICAL BOOKSELLERS AND PUBLISHERS, PHILADA. ANATOMY.

ELEMENTS OF PATHOLOGICAL ANATOMY.

By Prof. SAMUEL D. GROSS, M. D., Professor of Surgery in the Louisville Medical Institute, Ky.

Late Professor of General Anatomy, Physiology, and Pathological Anatomy in the Medical

Department of the Cincinnati College.

Second Edition. Illustrated by 50 Colored Plate Figures, and 250 Engravings on Wood by the first

artists. 1 super-royal 8vo. vol., extra sheep. <- « We recommend it as the most complete, and, on the whole, the least defective compilation on the subject in the Enelish laneruace."—Brit, and For. Med. Jour. ... . - .. , * v- . "That a second edition should now be called for, considering the size and cost of the work and on a subject which comparatively few practitioners are sufficiently industrious and pains-taking to investigate, is certainly

fla«Thatgirwmmhe'n^orth^refard^d as a standard work, and introduced into the library of every physician of therfntertorwho aims either to educate his pupils thoroughly, or keep himself informed on the impjovemente ofQMd branch of medical and surgical science, we cannot doubt » "Evidently it has been a labor of love on the part of the author, rather than a task; and he was fortunate in securing publishers who seem to h^ve entCTed" to hiB own spirit. The mechanical execution of the work is deserving of the highest praise."-

^lurthelo^fcomtlet^d useful systematic work on Pathological Anatomy in the English language. The colored engra^higsTd woodcuts are exceedingly well executed, and the entire getting up of the work does

m« %^£ttLl£?^^^'* works ever issued from the American press, and it does great honor

"S is XgeTher the most complete exposition of Pathological Anatomy in our language. "-Amer. Jour, of

"w^rwmmend the work to our readers as one calculated to advance the subject upon which it treats. We trusTtheToTmay enterExtensively into the hands of the profession, and that they will bestow on it careful

^TKTmTy^re^wfth advantage, * * * it proves him a man of industrious habits, and anxious to dif-

''SSSSrtat service on his countrymen."-^. CHr. Rev.

THE LONDON DISSECTOR, OR GUIDE TO ANATOMY:

for tf)« Wist of Stufctntsf,

Comprising a Description of the Muscles, Vessels, Nerves, Lymphatics, and Viscera of the Human

Body, as they appear on Dissection; with Directions for their Demonstration.

By EDWARD J. CHAISTY, M. D. 1 vol. 12mo. muslin. „.,.,_ v. «.„» «re .several of these dissecting-room companions, there is not one in the whole catalogue that w ™ K from ite ntrinsfc lul,1han theo!d London Eissector. With the taP™eme»*, of'^J^Ueut Lu^n catefuUy revised, it will prove a very economical as well as certain assistant; and it therefore com minds'itself to the student."-.BMton Med. and Surg. Jour. ^ 2 BARRINGTON AND HASWELL'S OUTLINES OF THE ARTERIES,

With short Descriptions: Designed for the Use of Medical Students. With. Colored Engravings.

By JOHN NEILL, M. D., Physician to Wills's Hospital, and Demonstrator of Anatomy in the University of Pennsylvania.

Second Edition Improved. " This book should be in the hand of every medical student. It is cheap, portable, and precisely the thing needed in studying an importaut, though difficult part of Anatomy."—Boston Med. and Surg. Journ. " Its chief excellency, however, is its mode of reference, in which it differs from the usual method of numbering the different vessels, and referring to their numbers in the accompanying explanation."—Med. Exam. EXTRACT FROM A LETTER OF PROF. WEBSTER. "I have examined it, and think it a v«ry useful work, so much so that I shall recommend it to my class, and adopt the arrangement in my description of that system." " We recommend every Student of Medicine to purchase a copy of this work, as a laboi-saving machine, admirably adapted to refresh the memory, with knowledge gained by lectures, dissections, and the reading of larger works."—K. Y. Jour. Med. " This work is from the pen of a Philadelphia anatomist, whose familiar knowledge of the subject hag been aided by the press, the result of which is a volume of great beauty and excellence. Its fine execution commends it to the student of Anatomy. It requires no other recommendations."— Wast. Juurn. of Med. and Surg. OUTLINES OF THE NERVES,

By the same Author. Second Edition Improved. "This volume is as beautiful a* it is useful.—one in which both author and publishers have united their efforts for the especial benefit of the student, to whom a more acceptable work could not be offered, for facilitating an adequate acquaintance with the elements of neurology. Like that on the arteries, it hn< the distinctive recommendation of the names being affixed to the trunks and ramifications of the nerves, and in this way, of saving a deal of trouble and time, and of impressing them more firmly on the memory."—But. Med. Sci. " In the plates delineating the origin aud course of the nerves, the student will find a clear and beautiful exhibition of this portion of anatomy."—West. Jour. Med. and Surg. " The difficulty of following a demonstration, so often complained of by students, can, we think, no longer exist with such a guide as this."—Phil. Med. Exam. " To obtain this general knowledge of the nervoiis system, tho student will find Dr. Weill's work of great value."—West. Lancet. " It deserves all the commendation we bestowed upon its predecessor, and will prove a most useful aid to the student commencing the study of the Nerves."—Am. Jour, of Med. Sciences. OUTLINES OF THE VEINS AND LYMPHATICS.

By the same Anthor. With Colored Engravings. " We admire the plan of the work, and think it well calculated to facilitate the progress of the student of medicine."—Missouri Med. and Surg. Journ. " We think it a very useful work fir medical students, for whom it is chiefly desi<rned. as being well calculated to facilitate their studies, and to obtain a clear and concise view of the Nervous and Lymphatic Systems."— iV. Y. Journ. Med. "Like its predecessors, this work is a convenient aid to the student."—Am. Journ. Med. Sc. *** The three works can be had bound together in one volume, or separately.

FmrszoLoav and hygisnts,

INCLUDING COLD, SEA, WARM, HOT, VAPOUR, GAS, AND MUD BATHS; Also on the Watery Regimen, Hydropathy, and Pulmonary Inhalation. With a Description of Bathing in Ancient and Mo.lern Times. By JOHN BELL, M. D.— 1 Vol. 12mo. "The work by Dr. Bell is the most complete monograph, we do not hesitate to say, on the subject, that has •ever issued from the press, and should find a place, as a work of reference, in the library of every practitioner. It is also, we think, one of the most systematic works ever printed in the United States; and in this respect contrasts most favorably with the greater portion of Analo-American literature."—Brit, and Foreign Med. Chir. "We wish for this volume a wide-spread and extensive circulation; one that shall be commensurate with its design and merits."—K. Y. Med. Journal. "No work in our language contains so large an amount of well digested information respecting the above subjects, and we have reason to feel proud that such an addition to the permanent literature of the profession should have been made by one of our citizens."—Report of the Committee of the American Medical Association on Medical Literature. * a. . * . .. ^ r> „ * , . " These are our sentiments, and they lead us at once to thank Dr. Bell for his unique production. Wo receive it not only as a boon and an honor to the American profession and to our countrymen in general, but as a tribute to humanity at large. And we are happy to know that it comes as the forerunner of another gift from one MEDICAL PUBLICATIONS. 3

whoso public and private life have long since stamped him as a true lover of his fellow-men, and an able as well as earnest advocate of all that is likely to improve their physical and mental being."—PkOada. Med. Examiner. Its appearance is most opportune; for the community generally are so arrayed either for or asrainst hydropatny as it is practised here, and so much error is repeated on both sides, that there was much danger lest tne truth should be entirely neglected. This temperate exposition of the whole subject commends itself not only to the profession, but more particularly to the public. It will be found to be of an eminent, popular character."—Lyterary World. "It would be a very equivocal recommendation to denominate the work the best systematic treatise on bathing m the English language, for, as we have already remarked, it is the only one of that description ac cessible to the great mass of American physiciaus, to whose patronage we strongly commend it."—Am. Med. Jour.

OBSERVATIONS ON CERTAIN PARTS OF THE ANIMAL (ECONOMY,

By John Hunter, F. R. S., Etc. With Notes, by Richard Owens, F. R. S.

ON REGIMEN AND LONGEVITY:

Comprising Materia Alimentaria, National Dietetic Usages, and the Influence of Civilization on

Health and the Duration of Life.

Fellow of the College of Physicians of Philadelphia.—1 vol. 12 mo.

ON THE SANATIVE INFLUENCE OF CLIMATE. BY SIR JAMES CLARK. 1 vol. 8vo. half sheep.

" It is unnecessary to say anything of this work, as its vitlue is too well known to the profession to require any fostering at this period. The present edition is greatly .superior to its predecessors."— Western Lancet. " For amount of information, variety of details, and important instruction relative to the interesting subject to which it is devoted, we believe this work is uneoualled. It has been reprinted in an elegant cheap form."__ Gazette. PATHOlOGr.

OUTLINES OF GENERAL PATHOLOGY, By GEORGE FRECKLETON, M.D. Fellow of the Royal College of Physicians, <Lc.

A TREATISE ON THE BLOOD, INFLAMMATION, AND GUNSHOT WOUNDS, By JOHN HUNTER, F.R.S. With Notes, by James F. Talker, Senior Surgeon to the St. George's and St. James's Dispensary, &c, &c.—1 vol. 8vo. sheep.

HISTORICAL NOTICES ON THE OCCURRENCE OF INFLAMMATORY AFFECTIONS OF THE INTERNAL ORGANS AFTER EXTERNAL INJURIES AND SURGICAL OPERATIONS. By WM. THOMPSON, M.D., Etc.

A TREATISE ON INFLAMMATION. By JAMES MACARTNEY, F.R.S., F.L.S., Etc. LECTURES ON THE BLOOD,

AND ON THE CHANGES WHICH IT UNDERGOES DURING DISEASE,

CHANGES OF THE BLOOD IN DISEASE. TRANSLATED FR03I THE FRENCH OF M. GIBERT, By JOHN H. DIX, M.D., M.M.S.S.—1 vol. 8vo. half sheep. "The treatise of M. Gibert is elaborate, and exhibits a very good view of the relations of the blood to the morbid conditions of the system."—Western Lancet. •' This is one of the best treatises on the changes of the blood in disease. It has been elegantly translated from the French by Dr. Dix, of Boston, and is published for a mere trifle, by the enterprising firm of Barrington & Haswell, of Philadelphia. It is a most valuable addition to a medical library."—IK Gazette. 4 BARRINGTON AND HASWELL'S A TREATISE ON THE CAUSES AND CONSEQUENCE OF HABITUAL CONSTIPATION.

By JOHN BURNE, M.D., Fellow of the Royal College of Physicians, Physician to the Westminster Hospital, etc.

1 vol. 8vo. half sheep. '■ For some interesting cases illustrative of this work, the author is Indebted to Dr. Williams, Dr. Stroud, Dr. Callaway, Mr. Morgan, Mr. Taunton, Dr. Hoots, Sir Astley Cooper, Sir Benjamin Brodie, Mr. Tupper, Mr. Bailer, It. Paris, .Mr. Dendy, Dr. Hen. U. Thomson," kc—Preface.

BEING AN ANALYSIS OF ITS IRREGULAR AND AGGRAVATED FORMS.

IXCLCIING HYSTERICAL HEMORRHAGE AND HYSTERICAL ISCUVRIA. WITH NUMEROUS ILLUSTRATIVE AND CURIOUS CASES. By THOMAS LAYCOCK, House Surgeon to the York County Hospital—1 vol. 8vo. half sheep. ON THE CAUSES AND SIGNS OF ACUTE AND CHRONIC DISEASE, FROM THE GREEK OF ARET.EUS.

By T. F. REYNOLDS, M.B., F.L.S., Etc.—1 vol. 8vo. sheep. "The correct detail of symptoms, the nervous style, the graphic delineation of disease, displayed in this author's work, the poetic and quaint fancies scattered throughout, give a certain value and interest, that may fairly excuse an attempt to reinvest part of them in a vernacular gaTb." " We certainly have no hesitation in recoimnending this curious volume to the notice of our readers. Its price is a mere trifle."—JXew York Lancet.

OUTLINES OF PATHOLOGICAL SEMEIOLOGY. TRANSLATED FROM THE GERMAN OF PROFESSOK 8CIIILL,

With Copious Notes, by D. SPILLAN, M.D., A.M., Etc.—1 vol. 8vo. sheep. "The signs of disease exhibited by the principal tissues and organs, arc treated of in a succinct and comprehensive manner, by Dr. Schill, and as a work of daily reference to assist in distinguishing diseases it cannot be too highly commended."—Bait. Journ. "An elegant and accurate translation of a very ingenious and instructive work. We do not know any other source from which we can so easily and profitably obtain all that is really useful in the semeiology of the ancients; and the erudite translator and editor has so very creditably supplied the deficiencies of the author's abrige of the labors of modern workers, in this most important department of modern science, that we can in good conscience commend the book as one of unequivocal merit."—Xew York Lancet. MATERIA MEDICA AND THERAPEUTICS.

A PRACTICAL DICTIONARY OF MATERIA MEDICA. Including the Composition, Preparation and Uses of Medicines; and a large number of Extemporaneous Formulae; together with important Toxicological Observations. By JOHN BELL, M.D., Lecturer on Materia Mcdica and Therapeutics, &c, Ac.—1 vol. 8vo. sheep. "Dr. Brande's is an excellent work, and with the retrenchments, additions, and alterations of Dr. Bell, may be regarded as one of the most valuable works on the Materia Medica we now possess. It has an important advantage over many of the treatises on this subject, in giving a large number of prescriptions for the administration of the principal articles. This renders it especially valuable to the young practitioner."—Bait. Jour.

A THERAPEUTIC ARRANGEMENT AND SYLLABUS OF MATERIA MEDICA,

By JAMES JOHNSTONE, M.D., Physician to General Hospital, Birmingham.—Small vol. 8vo. "Thi3 book cannot but be particularly useful to those who intend to lecture or write upon the Materia Medica; as well as to the students for whose particular use it is prepared."—Brit, and For. Med. Rev.

LECTURES ON BLOOD LETTING. By HENRY CLUTTERBUCK, M.D.—1 vol. Svo. half sheep.

THE MEDICAL PROPERTIES OF THE NATURAL ORDER RANUNCULACE/E. ETC. By A. TURNBULL, M.D. MEDICAL PUBLICATIONS. 5 THEORY AND PRACTICE OF MEDICINE.

LECTURES ON THE THEORY AND PRACTICE OF PHYSIC.

Fellow of the College of Physicians, Philadelphia; Member of the American Med. Association, and of the American Philosophical Society, etc., etc.; and

WM. STOKES, M.D., Lecturer of the Med. School, Park St., Dublin ; Physician to the Meath County Hospital, etc., etc.

Fourth edition, much enlarged and improved.—2 vols. 8vo. sheep. " This edition is greatly superior to those that preceded it, and have no hesitation in pronouncing the work a giM.-l one."—N. 0. Med. and Surg. Jour. " It is unnecessary to speak of the character of this work, as it is one with which the medical profession of this country are sufficiently acquainted. The present is the fourth edition, which has been carefully revised, and enlarged by the addition of new and useful matter."—Buffalo Med. Jour. " Dr. Bell has the gratification of knowing, from the rapid sale of the former edition, that his great labor has been rightly appreciated by the profession, and that Bell and Stokes's Lectures now rank among the standard works of the day."—Med. Ex. " This improved edition is in two heavy octavos, containing 17C0 closely-printed pages. Dr. Bell has added, with bis own prolific pen, over fourteen hundred of them, which gives it a strong claim to the title of an American treatise. The preface shows that industry, a crowning virtue in all departments of life, has been conspicuously displayed in this very learned effort."—Boston Med. and Surg Jour. " We cordially recommend such of our readers as have not yet supplied themselves to procure a copy of the present edition of these lectures, for we feel confident that they will never regret the time as lost, that they may devote to their perusal."—iV. Y. Journal of Medicine. " For all the qualities which the student or practitioner can desire in a work for study and reference, these lectures may be safely recommended, as comprising as much as could be brought within their limits of sound opinion and judicious practice."—Ifet. Jour. " With such additions and improvements, we consider the work one of the best of its kind with which we are acquainted."—Maryland Med. <& Surg. Journ. '• The work has now assumed the form of a quite complete system of medicine, equally valuable as a text-book to the student, and a book of reference to the practitioner." " We know of no book of the kind which we would more readily place in the hands of a student, or to which we would more readily refer the practitioner, for a hasty investigation of a subject."—Mew Eng. Quart. Jour. .... « It would be rather late in the day to attempt to pass judgment upon a work which has already received its stamp from the profession."—Clw.rUs.ton Med. Journ.

ILLUSTRATED BY CASES OF THE MOST IMPORTANT DISEASES.

From the Papers of ALEXANDER D. GALT, M.D., for many years an extensive practitioner in Williamsburg, Va.—1 handsome vol. 8vo. sheep.

FIVE DISSERTATIONS ON FEVER. By GBORGE FORDYCE, M.D., F.R.S.—Second American Edition, 1 vol. 8vo. "The nublishors have done an a-cei>table service to the profession in republishimr them."—Phit. Med. Exam. « Fordyce has not been excelled by any writer before or since his day ."-Buffalo Med. Journ •'Thedissertations which compose the work of Dr. Fordyce on Fever, are, of all his writings those which in an especial manner have established his reputation for sound medical views."-& Journ. Med. and Piwrm.

DISEASES OF THE LIVER AND BILIARY PASSAGES.

By Wm. THOMPSON, one of the Physicians of the Royal Lnfirmary of Edinburgh.

ILLUSTRATIONS OF THE LIVER AND SPLEEN.

By WILLIAM TWINING, Surgeon of General Hospital of Calcutta, &c, Ac—1 vol. Svo. sheep. « The work before us is an excellent compilation on the subject of hepatic affections, functional and structural; . T^ n U Vnfinitelv more valuable to practitioners and students than any original essay, however ably ™ted We cannordo better, therefore, than strongly recommend the work as the best in the English langu^on'tbc important subjects of which it tre&ta."-Mcdico-Chirur. Rev.

Clinical Remarks on some Cases of

LIVER ABSCESS PRESENTING INTERNALLY. By JOHN G. MALCOLMSON, M.D.,

Surgeon Hon. E. L C. Service, Fellow of the Royal Asiatic Society, Ac. 6 BARRINGTON AND HASWELL'S MEDICAL NOTES AND REFLECTIONS.

By HENRY HOLLAND, M.D., F.R.S. Fellow of the Royal College of Physician*, and Physician Extra, to the Queen.

HISTORY AND CURE OF DISEASES.

New and Handsome Edition, 1 vol. 8vo. " All who admire sound cliuical knowledge; all who wish t > obtain unadulterated facts collected at the bed-side, and untinctured with speculation or theory, will not fail to avail themselves of this masterly production of the renowned Hcberden."—X. Y. Journ. of Med. '•' Now regarded as one of the classic productions of the profession.'"—Xtw Orleans Med. and Surg. Journ.

SOURCES AND MODE OF ACTION OF FEVER.

"The volume before us abounds in details of a highly instructive kind, and manifests a vigorous and healthy tone of investigation, which, even in its indirect effects! cannot but be beneficially felt by the American reader." —Bulletin of Med. Science. '• Dr. Davidson evinces an intimate acquaintance with thes abject which he treats, and embodies in his essay a large amount of valuable matter. The subject is one uf intrinsic interest, and will well repay the student for the time and labor devoted to its examination."— WcsUrn Ljuicct.

ITS HISTORY, PATHOLOGY, AND TREATMENT.

Professor of the Institutes and Practice of Medicine in the Medical College of South Carolina.

1 small volume. Svo. muslin.

MACROBIN'S INTRODUCTION TO THE STUDY OF PRACTICAL MEDICINE.

Bring an Outline of the Leading Facts and Principles of the Science.—1 small vol. 8ro. half sheep. "Dr. Maerobia's work is largely madj up of the primipl s of medicine, embracing the pathology and etiolosy of disease, and may therefore be esteemed a nucleus around which the student may, with advantage, gather a more extended system."—Western Lancet.

DERANGEMENTS, PRIMARY AND REFLEX, OF THE ORGANS OF DIGESTION,

Ey ROBERT DICK, M.D., Author of "A Treatise on Diet and Regimen."—1 vol, Svo. sheep. '■ It is the fullest, most comprehensive, and decidedly the best accountof derangements of the digestive organs that we have encountered. While it embraces all that is important or interesting to be found in the writings of other authors, it contains much original information, which the physician will find of great practical usefulness."— Westtrnand Southern Medical Recorder. •• We recommend this volnme most warmly to the attention of our readers."—London Lancet. '• This volume may, in fact, be denominated with no small degree of propriety an encyclopedia of dyspeptic disorders."—X. Y. Lancet. "It is decidedly the best compilation in the English language on the extensive class of disorders and diseases comprehended under the term dyspepsia, united with a very large proportion of original matter, derived from the author's own experience."—Med. Chir. Reo.

EPIDEMICS OF THE MIDDLE AGES.

From the German of I. F. C. HECKER, M.D.,

NO. I.—THE BLACK DEATH IX TUP. FOURTEENTH CENTURY.

" Hecker's account of the " Black Death," which ravaged so bir^e a portion of the globe in the fourteenth century, may be mentioned a- a work worthy of our notice, both as containing many interesting details of this tremendous pestilence, and as exhibiting a curious specimen of medical hypothesis."—Cyclopaedia of Practical Medicine, NO. II.--THE DANCING MANIA.

"Medical History has long been in need of the chapter which this book supplies; and the deficiency could not have been remedied :it a better season. On the whole, the volume ought to be popular; to the profession it must prove highly iiee,vt:i!'e. as conveyinj: so much information, touching an important subject which had almost been suffered to 1* lmried in oblivion, and we think tbvt to Dr. Babington especial thanks are duo for having naturalized so in.,-re'tin,' a production. Tbe style of the translation, we may add, Is free from foreign idioms: it reads like an English original."—Lond. Med. Gaz. MEDICAL PUBLICATIONS. 7 A TREATISE ON TETANUS.

By THOS. BLIZARD CURLING, Assist. Surg, to the London Hospital, etc. 1 vol. 8vo. half sheep. Y "This book should be in the library of every surgeon and physician. It is a valuable work of reference. It does not pretend to originality, for originality on such a subject was not wanted. But a compendium 01 iacis was wanted, and such a compendium is this volume. We cannot part from Mr. Curling without thanking nun for the information we have received."—Med. Chir. Rev.

TREATMENT AND MANAGEMENT OF THE INSANE.

By I. G. MILLINGEN, M.D., Late Medical Superintendent of Lunatic Asylum, Hanwell, Middlesex, etc.—1 vol. Svo. half sheep. " Dr. Millingen, in one small pocket volume, has compressed more real solid matter than could be gleaned out of any dozen of octavos on the same subject. We recommend his vade macum as the best tning oi xne una we ever perused."—Dr. Johnson's Review.

A PRACTICAL TREATISE ON THE PRINCIPAL DISEASES OF THE LUNGS,

CONSIDERED ESPECIALLY IN RELATION TO THE PARTICULAR TISSUES AFFECTED, ILLUSTRATING THE

DIFFERENT KINDS OF COUGH. By G. HUME WEATHERHEAD, M.D., Member of the Royal College of Physicians, Lecturer on the Principles and Practice of Medicine, and on 'Materia Medica and Therapeutics, etc., etc.—1 vol. Svo. half sheep.

A TREATISE ON THE DIAGNOSIS AND TREATMENT OF DISEASES OF THE CHEST,

2d Edition, with an Introduction and Numerous Notes, by the American Editor.—1 vol. 8vo. sheep. "It is delightful, indeed, to contemplate the sound pathology and rational therapeutics which it inculcates;— so different from the swelling egotism, the groundless assertions, the illogical conclusions, and often empirical treatment) recommended in some of the modern works on these and other important medical subjects."-i/ed.

&« ^inconsiderable part of the book is made up of Dr. Bell's notes, and it now constitutes one of our most useful^treatises on the diseases of the chest, characterized by sound pathology and rational therapeutics."-.^

^lo^weU knoCn^retoe writings of Dr. Stokes, that no effort of the medical press in this country is necessary to increase their circulation. Young practitioners would find this volume a pathological guide, which they would be unwUlin^ to part with when made familiar with its intrinsic yalue »-ift»to» Med. and Surg. Journ.

THE DIAGNOSIS, PATHOLOGY, AND TREATMENT OF

By W. W". GERHARD, M.D., Lecturer on Clinical Medicine in the University of Pennsylvania, etc.-l vol. Svo. sheep. Third Edition, much improved.

"We would sav bv all means study this volume."—Buff. Med. Jour. T„-.^ « mvf- .ou',r r?;",y'TiUZ, nf rir Gerhard's well known work on thoracic diseases."—London Lancet. This is the third edition of ^' ^™^L whidTare constantly made against physical exploration in medicineTby ZlelT.S^StSS can never advance beyond the point atwhich they ceased to

16 « Ind^iS .Sfto be Invidious, we may not inaptly designate Dr. Gerhard as the Louis of America."

"HwortmhSoTtts Diseases of the Chest will be accredited as the highest authority on that subject."

- West. Journ. Med. o-^djurg. , D Gerhar(i for the excellent work with which he has presented

them a ^^O^^^^^^S^^ * «* »*" Sale°f *»» *"»* -**•"-**** Med. Exam. recommend the book of Dr. Gerhard as the fullest and most judicious manual, motionS^ff^Ti* «^-^ W canprocure,'-^e^ and Southern Recorder.

ON DISEASES OF THE HEART AND GREAT VESSELS.

Translated from the French, by WILLIAM A. HARRIS, M.D., U.S.N. _ "This is an excellent epitome of a large and important class of diseases-especially as to diagnosis. -Med.

Chir. Rev. ,8 BARRINGTON AND HASWELL'S ^This work, though issued under the modest title of a manual, is yet so comprehensive as to afford minute Instruction on every point of which it treats."—Phil. Med. Ex. " We do not know of any production in which so much positive knowledge has been compressed within mode- ^*!f^i?IB*tS, and.yet clearness of description presented, as in this manual."—Bulletin of Med. Science. " We hope this manual, comprising, as it does, a summary of what has been published in more elaborate works, wul be extensively read, and that the study of it may lead to a more correct appreciation of the character of these diseases."— West. Jour, of Med. and Surg. "The present treatise will prove of great value, as it reallv contains all that is well known on this most difficult yet important branch of pathology and therapeutics.'— West. Lancet. LECTURES ON SUBJECTS CONNECTED WITH CLINICAL MEDICINE.

AUSCULTATION AND SEMEIOLOGY.

Physician extraordinary to the Queen, and late Physician to St. Bartholomew's Hospital.

1 vol. 8vo. sheep. " It is classical in style, replete with facts, rich in illustration, sound in doctrine, and a legitimate product of the Hippocratic school of observation."—X. Y. Journ. Med. " Containing valuable matter presented in a highly agreeable manner."—Buffalo Med, Journ. " They contain clear, concise, practical views of semeiology, and of the value of symptoms, in the diagnosis and treatment of disease, which are not to be found in any other single work."—South. Journ. Med. and Phar. " The chapter on the Doctrine of Symptoms, embrace auscultation and the various physical signs of disease, and ought to be studied by all who aspire to a knowledge of these subjects."—Medical Examiner. "We consider this publication well deserving of that patronage which men of enlarged professional views should bestow upon works of the first character on practical medicine."—Boston Med. and Surg. Journal. LECTURES ON SUBJECTS

CONNECTED WITH C L I N I C A L M E D I C I N E,

COMPRISING DISEASES OF THE HEART.

Physician extraordinary to the Queen, and late Physician to St, Bartholomew's Hospital.

1 volume 8vo. sheep. " It is a deeply reflective volume, replete with results indicative of close observation, and abounding with hints and directions which cannot fail to give a strong and beneficial impulse to the study of cardiac disease."— Brit, and For. Med. Rev. "We know of no work where the reader will find so clear and easily intelligible a view of a difficult practical subject—the Diagnosis of Diseases of the Heart—as in Dr. Latham's two volumes."—Mcdico-Chirur. Review. " He will find in them much that no other work upon the subject contains, and what is even better, much that will move him to observe more closely, and ponder more earnestly, what is going on within his own experience."—Amer. Journ. Med. Science. " One of the most remarkable works which has, for a long time, been presented to the profession; a work full of original remark, abounding in correct analysis, just reasoning, clear and lucid expositions of doctrine, and judicious practical teachings."—South. Journ. Med. Pharmacy. " We commend the book most heartily to our readers, as one of high value, and not less pleasing than valuable."—Western Journal. " These have all been illustrated by the able and experienced author in a most interesting and lucid manner, so that hereafter no work will be regarded as more essential in studying diseases of the heart than this of Dr. Latham."—N. Y. Journ. of Med. " Throughout the whole work, we meet with the evidences of the deepest reflection, and of the most philosophical caution and acumen in weighing and analysing facts."—Land. Med. Gaz.

NATURE, CAUSES, AND TREATMENT OF ERYSIPELAS. By THOMAS NUXNELEY,

Lecturer on Anatomy, Physiology, and Pathology in the Leeds School of Medicine, Surgeon to the General Eye and Ear Infirmary, <fec, Ac.—1 vol. 8vo. sheep. " Nothing short of a perusal of the entire book will do justice to the author or reader."— Western Lancet. " The work in its entireness is one which will be accounted necessary to every physician's library."__Western Journ. of Medicine and Surgery. " Did our space allow, It would be both interesting and profitable to enter into a full analysis of this work • but we would advise our readers, one and all, to purchase it, and thus judge of its value from a personal examination of its pages."—X. Y. Jour. Med. and CoUat. Sciences. " Mr. Nunnelev contends, and we think with success, that puerperal fever and erysipelas are one and the same disease, modified by the seat of the inflammation."—N. Orleans Med. Jour. MEDICAL PUBLICATIONS. 9 PRACTICAL OBSERVATIONS ON DISEASES OF THEHEART, LUNGS, STOMACH, LIVER, ETC. OCCASIONED BY SPINAL IRRITATION, And on tlie Nervous System in general, as a Source of Organic Disease. Illustrated by Cases. By JOHN MARSHALL, M.D.-l vol. Svo. half sheep.

CLINICAL LECTURES. By ROBERT J. GRAVES, M.D., M.R.I.A., Professor of the Institutes of Medicine in the School of Physic, Trinity College, Dublin. Third American, from the Dublin Edition, with additional Lectures and Notes. By W. W. GERHARD, M.D., Lecturer on Clinical Medicine to the University of Pennsylvania, Physician to the Philadelphia Hospital, Blockley, Ac — 1 vol. 8vo. sheep. « The possessor of this treatise will actually have an embodiment of all that is modern in the science to which

|S5=^^SnS library of practical Medicine.;'—XY./?"«*■ . .. . scarcely a disease to which the human frame • r^^rtoes ^t'^^ln^mlSStto.^orlntid^TLrf as a guide to practice, especially gdlmcu^^ md **«* RWUW-

ANDRAL'S CLINIC ON DISEASES OF THE ENCEPHALON, it « " ABDOMEN. tt " " CHEST, Either of the Works can he had Separately. Three volumes 8vo. sheep. «TheW«e^i^ SURGERY.

THE COURSE OF LECTURES ON SURGERY, Delivered in the Royal College of Surgeons in Ireland, v, ♦!,„ l. te ABRAHAM COLLES, M.D., for thirty-four years Professor of Surgery in the College. ■ By the late A^**1.1 ,ml,rPB80f Mr Colles's name, any practical man looking over these pages would « Even without the precious impress°f Mr. ^oiieisii^j a u art »_£„■<. and For. Med. Rev.

^FeT^^^^^ ^Ch^hesltation^m^ volume which has Deen ouerw , Surg. , . „„,, nf tt,p«.e lectures with a very high opinion of the judgment and surgical , TuTen of^Tto P^rr ^ und^ra'ctical facts."-io«d Xf-f™. amanof accurate observation and extended experience: not ■ h" ?0^f P "dueton o7 a^mpiler who C Laired his knowledge of diseases only from the recorded observa- [ tions of ^ere."-^K Jbum. oj^ o{ ,ta technical verbiage, must read these lectures as they fell from j 10 BARRINGTON AND HASWELL'S PRINCIPLES AND PRACTICE OF SURGERY,

By FREDERICK TYRRELL, Esq. Fifth American, from the last London edition.—1 vol. 8vo. sheep. LECTURES ON THE PRINCIPLES OF SURGERY.

By JOHN HUNTER, F.R.S., With Notes, by James F. Palmer, Senior Surgeon to the St. George's and St. James's Dispensaries, etc., etc. With plates, 1 vol. 8vo. sheep.

LISTON'S ELEMENTS OF SURGERY.

Edited by' SAMUEL D. GROSS, M.D.,

Professor of Surgery in the Louisville Medical Institute. Author of Elements of Pathological Anatomy, etc., etc.,

Fourth American, from the last London edition, with upwards of one hundred and sixty illustrative Engravings. 1 vol. 8vo. sheep.

" We must not forget to mention that the volume is rendered still more attractive by the addition of numerous wood engravings (some of them introduced by Dr. Gross), all finely executed. These will be found of very considerable advantage to the student, materially assisting him in comprehending the explanation of morbid structure.''—Western Jour, of Med. and Surg. " We are here presented with a republication of Mr. Listen's admirable and much praised work on Surgery, which has been subject to the alembic of a critical and learned friend, Dr. Gross. He has added ' copious notes and additions,' such as the progress of surgery in the United States demands in order to meet the wants of the surgeon; and has bestowed unwearied pains to adapt it to the present condition of things. It is modern in every respect, since it contains tlie latest improvements, and the very last discoveries, in the domain of operative surgery, both here and in Europe."—Boston Med. and Surg. Jour. " In another essential feature this edition is greatly improved. With the principles is taught also with it the practice of surgery; and both morbid structure and operations are doubly described; first by the author and editor, and next by the graver of the artist."—Z?uH. Med. Scien. " Mr. Listen has seen much, thinks accurately, and speaks independently. From a volume written by such a man, more really valuable practical instruction is to be derived than from all the books that were ever compiled." — Western and Southern Med. Recorder. " It embraces all the principles of surgery, which the work on the operations does not."—& Journ. of Med. and Pharm. « " Few living authors are better qualified for expounding the principles of surgical science, and the evidence of these attainments are abundant in the work before us."—Philad. Examiner. " This is a work of established reputation. It has gone through two editions in Great Britain, and the same number in this country. The additions of the American edition are copious, and add materially to the value of the work."—Amer.Jour. Med. Sciences. " The notes and additions by Prof. Gross, are well arranged and judicious, supplying some evident deficiencies in the original work. It is no mean praise, that this treatise has so readily found its way into the hands of the profession."—Western Lancet.

NATURE AND TREATMENT OF DEFORMITIES.

Surgeon to the Royal Orthopaedic Hospital.—lvol. royal 12mo., with numerous Hlustrations. " They constitute a work both original and useful. Mr. Tamplin, if we are not greatly mistaken, will be generally admitted to have performed a useful task well, and to have made substantial additions to the treatment of deformities without any parade or self-laudation."—Bulletin of Med. Science. " To those numerous members of the profession desirous of making themselves acquainted with the most recent and approved principles of treating a class of diseases which have hitherto been considered to fall within the special domain of quackery, we cordially recommend Mr. Tamplin's valuable lectures."—Lond. Med. Gaz. " We strongly recommend our professional friends generally, and especially such as reside in the country, to have a copy of it beside them."—Med. Chir. Rev. " This work is practical in the strictest sense of the word, being confined to facts and illustrations of principles, furnished in a plain, brief, and systematic style."—S. Med. and Surg. Journ. " Their collection into a separate volume is a just tribute to their intrinsic merit, as well as to the high character of their author."—St. Louis Med. and Surg. Journ. "The author is a sound, practical man, and in these lectures he gives us the result of a large experience in one of the best conducted and most valuable charities of London; a charity devoted exclusively to the treatment of deformities."—Buffalo Med. Journ. " This work may be consulted with much profit by the surgical reader; and we therefore strongly recommend our professional friends generally, and especially such as reside in the country, to have a copy of it beside them." —Med. Chir. Rev. MEDICAL PUBLICATIONS. 11 HUNTER ON THE VENEREAL DISEASE. With Notes, by Dr. BABINGTON. With Plates.—1 vol. 8vo.

"Under the hands of Mr. Babington, who has performed his task as editor in a very exemplary manner, the work has assumed quite a new value, and may now be as advantageously placed in the library ot tlie stuaeni as in that of the experienced surgeon."—Brit, and For. Med. Rev. . . ,. "The notes, in illustration of the text, contain a siunmary of our present knowledge on the ™oject, tne manner in which these notes are constructed is at once clever and perspicuous; and the modes ot treatment prescribed, spring from a right apprehension of the disease. We would recommend to the reader the note on ine primary veneroal sore; the note itself is an essay in every word of which we fully concur. —Mea. (xaz. LECTURES ON VENEREAL AND OTHER DISEASES ARISING FROM SEXUAL INTERCOURSE. By M. RICORD. "Twentyeight lectures are given, which fully and minutely embody the ^^^.%^L^ ^as day, in the treatment of those maladies having an origin in the source adverted to in^tho title-sheet, ltnas an advantage over more costly books upon the same topic, because it is muUum in parvo, and may be purchased for a trifle."—Boston Med. and Surg: Journ. . . fill th^ hi "The present lectures, clinical in their character, and appearing » » "ndnl?i*,*™w?Sn will cjnniend tus which the profession at large have for some years felt. We regard the work as one which wdl «m»a itself to the profession as the most concise and able exposition of the doctrines of syphdis^ -^^£<* "We cannot close this notice of M. Ricord's Lectures without expressing an approbation^of the mam n which the reporter and translator has executed his task; nor without again repeating the high estimation ^&1^^^iltfS£^£^^^ snould 1- in the library of every medical man." —Philadelphia Examiner.

ON CURVATURES AND DISEASES OF THE SPINE, INCLUDING ALL THE FORMS OF SPINAL DISTORTION. By R. TV. BAMPFIELD, One of the Surgeons to the Royal Metropolitan Infirmary for Diseases of Children. Edited by J. K. MITCHELL, M.D., Professor of the Practice of Medicine in the Jefferson Medical College of Philadelphia, Ac. "Tho Tm best treatises on spinal diseases and their treatment extant."—Medical Examiner "We he^rtiS recommendthisP book to all who feel an interest in the matter, and especially in these days ^T^reatiX "iTa ve'rfvalulwe on^and Cheerfully recommend it to the profession."-^ OrUan, Medical Journal. A TREATISE ON THE STRUCTURE, ECONOMY, AND DISEASES OF THE EAR. By GEORGE PILCHER, Late Lecturer on Anatomy, Lecturer on Surgery, and Senior Surgeon to the Surrey Dispensatory. First American, from the second London edition, with Notes and numerous Illustrative Plates. 1 vol. Svo. sheep.

^Jot^tr%l ^y^jffj£^^ on the ear deserves to^ran^m^ 'tS^^t^^r^^^ but two generally neglected, departmentoTs'urgery t^whlehU^"^^ work, and must haye a great Ji^^SS^tffiS ahou^hf anatLy^iseasJs of the ea,"-.V. Y. HeraM.

A TREATISE ON THE TEETH. f By JOHN HUNTER. With Notes bv Thomas Bkll, F.R.S. With Plates.- 1 vol. Svo. sheep. 1 \C ♦ Jh • „Hif«l bv Mr Bell a Gentleman accomplished in his art. Mr. Bell has studied' "The treatise on the teeth „ edted by Mr Ml •^e .^^ at thefoot of the page corrects the, »eXb^^ »d pathology ."-Med. Gaz. 12 BARRINGTON AND IIASWELL'S THE NATURAL HISTORY AND

DISEASES OF THE HUMAN TEETH.

By JOSEPH FOX, M.R.C.S.L. Lecturer on the Structure and Diseases of the Teeth, at Guy's Hospital, Ac.

First American, from the third London edition.

REM0DE1ED, WITH AN INTRODUCTION, AND NEARLY TWO-THIRDS OF ADDITIONAL MATTER. By CHAPIN A. HARRIS, M.D., D.D.S.

Professor of Practical Dentistry and Dent Pathol, in Baltimore College of Dent Surgeons, Ac.

Illustrated with Thirty Plates.—1 vol. super-royal, 8vo. sheep. "On the whole, considering the vast amount of practical information it contains, the judicious arrangement of its subjects, and last though not least, the great number of valuable engravings, many of which are not to be met with elsewhere, it is a work which we think every dental student, and especially practitioner, should possess. The plates alone are worth the price of the book."—Am. Journ. of Dental Science. " The known character of this work, together with the reputation of the American Editor, renders it unnecessary for us to say anything in its favor, except that the engravings are executed in the best manner, and the paper and type correspond; and though far superior to, it is sold at about one-third the price of the English edition."—Dental Intelligencer. '• The present edition comes forth with the advantages of a careful revL-ion, and the sanction of a distinguished teacher and practitioner of the dental art. That these additions are judicious, we need no better guarantee than the .known competency of the editor."—Phil. Med. Examiner. " Its intrinsic scientific worth, the number and beauty of the engravings, and the paper and typography, altogether entitle it to rank among the first if not the very foremost of the many works issued of late years on the anatomy and diseases of the teeth, and their curative treatment."'—Bulletin of Mul. Science.

OR HINTS ON THE EVERYDAY DUTIES OF THE SURGEON.

Lecturer on Minor Surgery, Fellow of the College of Phvsieians, etc., etc.

Illustrated by two hundred and forty-seven engravings. 1 vol. 12mo. 3d edition, much enlargod. " And a capital little book it is. . . Minor Surgery, we repeat Is really Major Surgery, and any thing which teaches it is worth having. So we cordially recommend this little book of Dr. Smith'.-."—Med. Chir. Rev. "This beautiful little work has been compiled with a view to the wants of the profession in the matter of Bandaging, ic, and well and ably has the author performed his labors. Well adapted to give the requisite information on the subjects of which it treats."—.V. I. Examiner. "The directions are plain, and illustrated throughout with clear engravings."—London Lancet. " One of the best works they can consult on the subject of which it treats.''—Southern Journ. Med. and Pharm. " A work such as the present is therefore highly useful to the student, and we commend this one to their attention."—Am. Journ. of Med. Sciences. " No operator, however eminent, need hesitate to consult this unpretending yet excellent book. Those who are young in the business would find Dr. Smith's treatise a necessary companion, after once understanding its true character."—Boston Med. and Surg. Journ. " No young practitioner should be without this little volume; and we venture to assert, that it may be consulted by the senior members of the profession with more real benefit tiian the more voluminous works."—Western Lancet. XKIDWXFZIXt.'X' AND DI33ASES OF WOMEN.

LECTURES ON THE THEORY AND PRACTICE OF MIDWIFERY, By ROBERT LEE, M.D., F.R.S., Fellow of the Royal College of Physicians, London; Physician to the British Lying-in Hospital, and Lecturer on Midwifery at St. George's Hospital.

Illustrated with numerous Wood Engravings.—1 vol. 8vo.

" One important feature is the introduction of tables of the results of certain operations, as of craniotomy, and of certain diseases uf the puerperal state, as puerperal fever; which constitute a statistical ba^is for future observations and a present support for active and available practice."—Bulletin of Med. Science. " It is the production of a highly cultivated and practical mind, and has been elaborated with a degree of judgment and care which must render the Lectures a valuable record of professional learning and experienoe." — Western Journal of Med. S'-iences. •• Every passage will indicate in the author a discriminating, practical mind, enlightened by learning, and extensive observations." '• It is a store-house of facts from which the student may enrich his mind, and to which the practitioner may apply to refresh his memory."—Western Jour. " The aim of the publishers was to give to the profession one of the very best systems of midwifery in the lanouage for the least money—to place a volume of unquestionable excellence within the reach of every medical man in the country. They have been successful."—Ibid. " The present production of Dr. Lee will always rank high, as the offspring of a vigorous mind, stored with all the learning relating to the subject, and enriched with the results of the most extensive experience."—X. Orleans Med. Jour. MEDICAL PUBLICATIONS. 13 r "I shall take advantage of the present occasion to refer you to that charming volume, < Lectures on the Theory «nd Practice of Midwifery, by Robert Lee, M.D., F.R.S., Ac, &c.,' a book which I could desire to be in the hands of every one of my pupils, as I look upon its author as the ablest man in all England, in this part of science and practice."—Meig's Letters on Female Diseases. <

LECTURES ON THE PRINCIPLES AND PRACTICE OF MIDWIFERY,

Edited by Charles Severn, M.D.—1 vol. 8vo. sheep.

"The eminently fluent and agreeable style—the large and accurate information—the great experience, tool original mind of Dr. Blundell, have secured for him a very enviable reputation as a public lecturer. It isimpossible to read these lectures without beins delighted—it is equally impossible to avoid being instructed, were these discourses more generally diffused and studied here—were their sound and judicious directions rccoliectea, and their salutary cautions observed, we would hear of fewer cases of malpractice. ^This work torms a complete system of midwifery, with the diseases of the puerperal state and of the infant.'—X. Y. Lancet.

AN ACCOUNT OF SOME OF THE MOST IMPORTANT

DISEASES PECULIAR TO WOMEN.

By ROBERT GOOCH, M.D.—1 vol. 8vo. Second Edition.

"Calmly and clearly ho investigates all thu phenomena of a disease, and simply registers precisely whatis essential."—Boston Med. and Surg. Journ. „ ~ %r . T "Dr. Gooch was an original thinker, and excellent observer. '—Buff. Med. Jour.

A PRACTICAL COMPENDIUM OF MIDWIFERY.

By the late ROBERT GOOCH, M. D.

Prepared by George Skinner, Member of the Royal College of Surgeons, London.

Fourth American edition.—1 vol. 8vo. sheep.

"Wherever civilization and science have been introduced, there the name and character of Dr. Gooch are

^We know Tno^medial wo7k Sicontains, in an equal number of pages, so much that is practically useful

content to^enend forknowledge on the compendium and text books, prepared to facilitate the progress of the Zdent but are disposed to seek for information at its original source. It may be well for the young s^tudent student, du; arc> "^V^, iudement to rely upon the digest prepared for his guidance; but the advanced stuaen? andX^Utton^hoJ wT^to bTsmne^hing mo« than a mere routinist, must consult the great ^ter^of our «cimc^ study their opinions in their own writings, compare their views, and form his own opinions. TmongthS always stand pre-eminent and the profession are under obhga, tion^ ^ the publfshersfor placing bis works within their reach."—W. Journ. Med. Science.

THE HISTORY, PATHOLOGY, AND TREATMENT OF

PUERPERAL FEVER AND CRURAL PHLEBITIS.

By Drs. GORDON, HEY, ARMSTRONG, and LEE.

With an Introductory Essay, by Charles D. Meigs, M.D.,

Professor of Obstetrics, and the Diseases of Women and Children, in the Jefferson Medical Colrr lege, Philadelphia.—1 vol. 8vo. sheep.

"We have peculiar satisfaction, in announcing the publication of this very judiciously arranged series of "We have^™»»r _■ 't t and interesting diseases, which demand the attention of the physician." ^Mei£s7nT^^ *° read with profit He speaks in the highest 1 « if .nmmendation of Dr". Gordon's invaluable treatise-a treatise which cannot be too generally diffused teTAudiedAlto^e her this volume presents the most acceptable and useful compend of the doctrines and prac and studied, ^iw cuicr >,ur■» ^ , Puerpcral Fever,' with which we have ever met."—X. Y. Lancet. ti^^tbe^™x^o^^^rtrSu comprises presents an invaluable mass of facts in relation to Child-bed

^tTer^n'^ « !Jp1 l's voluml I wouldnot take the trouble to write this letter; for I believe, that a study of that voumf Bnd ""*f""™^^wth«Treading of it, but a careful study and a conscientious examination of that volume alone^is enougK aSsStion on the subject of cbild-bed fever, whether sporadic or epidemic."-^ Letters on Female Diseases. 14 BARRINGTON AND UASWELL'S LECTURES ON THE FUNCTIONS AND DISEASES OF THE WOMB.

By CHARLES WALLER, M.D., Bartholomew's Hospital.

ON DISEASES OF THE UTERUS AND ITS APPENDAGES.

By M. LISFRANC, La Pitie Hospital.

ON DISEASES OF THE PUERPERAL STATE.

By J. T. INGLEBY, Edinburgh.—1 vol. 8vo. sheep.

"We can very cordially recommend them as affording a concise and practical exposition of the pathology and treatment of a most important class of diseases, and which cannot be too attentively studied. — X. 1.

"The present volume contains a short and succhict practical account of the principal morbid states either of the functions or the structure of the womb, the best methods of distinguishing them, and the means which experience has shown to be the most effectual in removing them. The reader will find that he obtains, in a small compass, adistinct view of the nature and treatment of each disorder."—Edinb. Med.and Surg.Journ. TOXICOLOGY.

IN RELATION TO MEDICAL JURISPRUDENCE, PHYSIOLOGY AND THE PRACTICE OF PHYSIC.

By ROBERT CIIRISTISON, M.D., F.R.S.E.,

Professor of Materia Medica in the University of Edinburgh, Ac, Ac. "We cannot but hail with satisfaction a new edition of this standard classical book. Its merits are too well acknowledged for it to be necessary to say anything further in its behalf. Wherever Toxicology is known as a science. Professor Christison's Treatise is received as an authority of the greatest weight. -Laruxt. "It has for a long period, been in the hands of barristers, who have not failed to make a good use of it in the cross^xamlnation of medical witnesses; and we believe there are few medical men who venture into the witness DoTon atrial for poisoning, without having at least consulted it respectmg some point on which their evidence is

"^Dr^hristison^i's a'v^'sjerior guide'for the general practitioner and student."-^. C/iir. Rev " We are freeto say that it is the best book on the subject in the Enghsh language.' - Western Lancet "This book is of the very highest authority on the subject of poisons, and may be said to exhaust it. —West-

*"" The",a^thorrof it has, with singular industry, brought within the compass of a single volume every variety of ulfulhrfornlation and illustration connected with the subject. It is an invaluable addition to the library

*£r£K^7^™&5^1>e™r>>rh* whole subject is clearly and well arranged and the - svmot^ "ffecstand tests of different poisons very fully and plainly stated Accept my thank s for the book." ^eItrTct' Irom 1 Letter op Judge Story -" I return youmy sincere thanks for your kindness in presenting me Extract from a j.LiitK Treatise on foi?ons. I shall certainly recommend it to be purchased for Zfll7d^"^S^^^ya^in& a high rank for the students of MedicalJurisprudence."

PRACTICAL TREATISE ON THE DISEASES OF CHILDREN.

By JAMES M. COLEY, M.D., Member of the Royal College of Physicians in London, Ac. • I a- „„..= nr ,v,;i,ir»n r«inires the exercise of all our perspective faculties, and every aid J^^^^V^^t^S^^^ -ems reral^weU fitted for consultation on this ^throu^h the medium of the.pages which lie *-^*-^ M JotirnaL

PRACTICAL TREATISE ON THE DISEASES AND MANAGEMENT OF CHILDREN,

By RICHARD T. EVANSON, M.D., Professor of Medicine, and

Henry Maunsell, M.D., Professor of Midwifery in the College of Surgeons, Ireland.

Edited by D F. Cosdie, M.D., From the Fourth Dublin Edition.-l vol. Svo. sheep. MEDICAL PUBLICATIONS. 15 " The second chapter embraces the Management and Physical Education of Children. This chapter ought to be printed in gold letters, and hung up in tlie nursery of every family. It would save many lives, and prevent much suffering."—Medico-Chirurg. Rev. '• As this Practical Treatise on the Diseases of Children has before been made known to the medical public, we dare not suppose it a new thing to any intelligent practitioner in this country : still, there may be those who do not own a copy—and to such there is nothing ungenerous in saying we with that they may always have it in their power to consult such authority."—Boston Med. and Surg. Journ. " The present edition is enlarged, and in its present form constitutes one of the best works on the subject in our language.'—1'ialad. Med. Exam. A TREATISE ON THE DISEASES OF CHILDREN.

WITH DIRECTIONS FOR THE MANAGEMENT OF INFANTS.

By the late MICHAEL UNDERWOOD, M.D.

With Notes, by S. Merhiman, M.D., Marshall Hall, M.D., and John Bell, M.D.

From the ninth English Edition, with Notes, 1 vol. Svo. sheep.

A MANUAL OF EXAMINATIONS

UPON ANATOMY AND PHYSIOLOGY, SURGERY,

PRACTICE OF MEDICINE, CHEMISTRY, MATERIA MEDICA, OBSTETRICS, ETC.

TO WHICH IS ADDED A MEDICAL FORMULARY, COMPRISING NEARLY FIVE HUNDRED OF THE MOST RECENT ANO APPROVED PRESCRIPTIONS.

Designed for the use of Students of Medicine throughout the United States.

By J. L. LUDLOW, M.D. Second Edition, revised and enlarged. 1 vol. 12mo.

"In this 'Manual of Examinations' the questions are clearly put, and, with few exceptions, well and distinctly answered." "The Manual will be found to be equally available at the three schools in Philadelphia, as at the two in New York, or those of Louisville, Lexington, and Cincinnati, or of Charleston, Augusta, and New Orleans, not to mention the numerous confrcries for teaching down East."—Bull. Med. Science. " We have no hesitation in saying, that Dr. Ludlow's Manual is decidedly the best, both in relation to comprehensiveness and general accuracy, that has yet been published in this country."—Western Lancet. " Dr. Ludlow discovers a minute knowledge with all the leading departments of professional lore, which h< Imparts agreeably. lie is careful to be exact, without being redundant in any paragraph."—Boston Med. one Surg. Jour. 11 Between all the classes whose comfort the Student's Manual is designed to promote, we should think ii would obtain not a little currency."— West. Journ.

AND ON PREPARATIONS IN ANATOMY, PATHOLOGY, AND NATURAL HISTORY.

Translated from the French of GANNAL, with Notes and additions, by R. HARLAN, M.D. ' IS MEDICAL SCIENCE FAVOURABLE TO SCEPTICISM!

By JAMES W. DALE, M.D., of Newcastle, Del.

CONNECTED WITH THE HISTORY AND PRACTICE OF MEDICINE AND SURGERY.

By THOS. JOSEPH PETTIGREW, F.R.S., F.S.A.

Doctor of Philosophy to the University of Gottingen, Ac, Ac. " The book will prove instructive, not only on account of the extensive learning which it displays, but tl numerous and curious facts which it develops."—X. Orleans Med. Journ. " Mr. Pettigrew's book is amusing to such as are inclined to smile, and instructive to those who are willh to reflect."—Med. Chir. Rev. " From the follies of the past we may derive wisdom for the future, and there is much in the volume befo us that may be profitably used for this purpose."—Med. Exam. " It is the common-place book of a literary physician, with a running commentary, giving a unity andoe tinuity to the mosaic."—Brit, and For. Med. Rev. " We do not know of pleasanter reading, either for the physician in the between-wbiles of professional Mffic or for the general reader who loves to study human nature in its external and often eccentric workings." Bulletin of Med. Science. " We heartily commend this little work to the curious of all classes of readers."—X. Y. Journ. of Med. " Wo take leave of his book, from which we have derived not only entertainment but instruction."__Weste Journal. 16 BARRINGTON AND HASWELL's MEDICAL PUBLICATIONS. MEDICAL AND TOPOGRAPHICAL OBSERVATIONS UPON THE MEDITERRANEAN,

PORTUGAL, SPAIN, AND OTHER COUNTRIES. Br G. R. B. HORNER, M.D., U.S.N. With Engravings. 1 volume 8vo. half sheep.

6i An uncommonly interesting book is presented to those who have any disposition to know the things medical in Portugal, Spain, and other countries," and -'will doubtless be read, also, with marked satisfaction by all who have a taste for travels."—Boston Med. and Surg. Journ. JOHN HUNTER'S WORKS.

Comprising hit Lectures on the Principles of Surgery ; A Treatise on the Teeth ; Treatises on Venereal Diseases; Treatise on Inflammation and Gunshot Wounds; Observations on certainparts of the Animal Economy ; and a full and Comprehensive Memoir.

Each of the Works are edited by men of celebrity in Medical Science, and the whole under the superintendence of

JAMES F. PALMER, of the St George's and St. James's Dispensary.—4 vols. 8vo. This is the only complete edition of the works of the distinguished physiologist ever published in this country. " One distinctive feature of the present edition of Hunter's works has been already mentioned,, viz: In the addition of illustrative notes, which are not thrown in at hazard, but are written by men who are already eminent for their skill and attainments on the particular subjects which they have thus illustrated. Uy this means, whilst we have the views of John Hunter in the text, we are enabled, by reference to the accompanying notes, to see wherein the author is borne out by the positive knowledge of the present day, or to what extent nis views require modification and correction. The names of the gentlemen who have in this manner assisted Mr. Palmer, are guarantees of the successful performance of their task."—Med. Gaz.

I THE LIFE OF JOHN HUNTER, F.R.S.

"In the summing up of Mr. Hunter's character, Mr. Ottley exhibits equal judgment and candor."—Brit, and %r. Med.

' THE PHILOSOPHY OF MARRIAGE,

*■ IN ITS SOCIAL, MORAL, AND PHYSICAL RELATIONS,

o WITH AN ACCOUNT OF THE DISEASES OF THE GENITOURINARY ORGANS.

WITH THE PHYSIOLOGY OF GENERATION IN THE ANIMAL AND VEGETABLE KINGDOMS.

Member of the Royal College of Physicians and Surgeons in London, Ac.

« Members of the Medical Profession will find in it much that is curious and entertaining, as rare <ro, aneeotes, recondite opinions of eminent men, interspersed with useful med.cal instruction."—-PhUad. Med. team '*Dr Kyanis above reproach or suspicion; and with a singular degree of candor and independence cxplans^ i atrue and philosophical manner, every branch of the subject which he considers essential to be underwood by all intelligent persons."—Boston Med. Surg. Jour. THE GUMS %H 1ATE DISCOVERIES ON THEIR STRUCTURE, GROWTH, CONNECTIONS DISEASES AND SYMPATHIES. Er GEORGE WAITE, Member of the London Royal College of Physicians. «^» BARRINGTON A HASWELL have constantly upon hand a large and varied assort-

°SCH00L, THEOLOGICAL, MEDICAL, CLASSICAL, AND GENERAL LITERATURE,

WHICH THEY WILL FURNISH AT JH&~ THE LOWEST CASH PRICES.

*j * Orders from the country thankfully received and promptly attended to. NLM011821728



====================================================================================================
VOLUME II
The Natural History and Diseases of the Human Teeth (notes by Thomas Bell); A Treatise on the Venereal Disease
====================================================================================================

JAMES F. PALMER, SENIOR SUBGEON TO THE ST. GEOBGE's AND ST. JAMEs's DISPENSARY, FE1EOW OF THE BOYAE MEDICAL AND CHIBUBGICAL SOCIETY OF LONDON, ETC., ETC. VOL. IT- ILLUSTRATED WITH NUMEROUS ENGRAVINGS NATURAL HISTORY AND DISEASES OF THE HUMAN TEETH; WITH NOTES BY THOMAS BELL, F.R.S.

A TREATISE ON THE VENEREAL DISEASE; WITH NOTES BY GE0RGE_fi^4BISGT0N. ___ i LIBRAK\ j SURGEON GENERAL'S OFFICE j

: JSftflata Wia:......„___ ' HASWELL, BARRINGTON, AND HASWELL. NEW YORK: J. & H. G. LANGLEY. 1841. wz. Mo

mi TREATISE THE NATURAL HISTORY AND DISEASES HUMAN TEETH:

EXPLAINING THEIR STRUCTURE, USE, FORMATION, GROWTH, AND DISEASES. IN TWO PARTS J bv ■'■'-' ;';»*■■ BY JOHN HUNTER, F.R.S. With iiOtOS

Fellow of theLinnean Society; Fellow of the Geological Society; Fellow of the Royal Medical and Chirurgical Society of London; Corresponding Member of the Society of Natural History of Paris; Lecturer on Comparative Anatomy at Guy's Hospital, etc., etc. J.i X JL* j.\.2:y.. i_v > I SURGEON GENEHALS UM HASWELL, BARRINGTON, AND HASWELL 393 MARKET STREET. 1841. 0 CONTENTS PART I.

Preface of the Editor.—Of the Upper Jaw—Of the Lower Jaw—Of the Alveolar Processes—Of the Articulation of the Lower Jaw—Of the Motion in the Joint of the Lower Jaw—Of the Muscles of the Lower Jaw—Of the Temporal Muscle—Of the Internal Pterygoid Muscle— Of the External Pterygoid Muscle—Of the Superior Digastric Muscle —Of the Structure of a Tooth—Of the Enamel—Of the Bony Part of a Tooth—Of the Cavity of the Teeth—Of the Periosteum of the Teeth —Of the Situation of the Teeth—Of the Number of Teeth—Of the Incisores—Of the Cuspidatus—Of the Bicuspides—Of the Grinders— Of the Articulation of the Teeth. Of the Gums—Of the Action of the Teeth arising from the Motion of the Lower Jaw—General Comparisons between the Motion of the Jaw in young and in old People—Of the Formation of the Alveolar Process— Of the Formation of the Teeth in the Foetus—Of the Cause of Pain in Dentition—Of the Formation and Progress of the Adult Teeth—Of the Manner in which a Tooth is formed—Of the Ossification of a Tooth upon the Pulp—Of the Formation of the Enamel—Of the Manner of Shedding of Teeth—Of the Growth of the two Jaws—The Reason for the Shedding of the Teeth—Of the Cavity filling up as the Teeth wear down—Of the continual Growth of the Teeth—Of the Sensibility of the Teeth—Of Supernumerary Teeth—The Use of the Teeth so far as they effect the Voice—Of the Class, among Animals, of the Human Teeth—Of the Diseases of the Teeth—Of Cleaning the Teeth—Of Transplanting the Teeth. PART II.

Introduction . • • • • . p. 59 Chap I.__Of the Diseases of the Teeth, and the Consequences of them ...-••• 60 1. The Decay of the Teeth, arising from Rottenness—Symptoms of Inflammation—Stopping of the Teeth.—2. The Decay of the Teeth '* contents.

by Denudation.—3. Swelling of the Fang.—4. Gum Boils.— 5. Excrescences from the Gums.—6. Deeply seated Abscesses in the Jaws.—7. Abscess of the Antrum Maxillare.

Chap. II.—Of the Diseases of the Alveolar Processes, and the Consequences of them ..... 78

Chap. III.—Of the Diseases of the Gums, and the Consequences of them . . . . . . 81 1. The Scurvy in the Gums, vulgarly so called.—2. Callous Thickenings of the Gums.

Chap. IV.—Of Nervous Pains in the Jaws . . 83

Chap. V.—Of the Extraneous Matter upon the Teeth 84

Chap. VI.—Of the Irregularity of the Teeth . 85

Cahp. VII.—Of Irregularities between the Teeth and Jaw 90 Of Supernumerary Teeth.

Chap. VIII.—Of the Under Jaw . . . 91

Chap. IX.—Of Drawing the Teeth ... 92 Transplanting Teeth—Of the State of the Gums and Sockets—Of the Age of the Person who is to have the Scion Tooth—Of the Scion Tooth—Of replacing a Sound Tooth when drawn by Mistake—Of Transplanting a Dead Tooth—Of the immediate Fastening of a Transplanted Tooth.

Chap. X.—Of Dentition ..... ioi Of the Cure—Of Cutting the Gums—Cases. PREFACE. The state of Dental Surgery at the period when Hunter wrote the following work was perhaps lower than that of any department of professional science or practice. The treatment of the teeth was still consigned to the hands of the ignorant mechanic, whose knowledge was limited to the forcible extraction of aching teeth, the manufacture of substitutes for those which were lost, and some rude methods of filling the cavities produced by decay. That this state of a branch of practice, as susceptible of a connexion with physiological and pathological science, and as improveable by such a connexion as any other, should have early attracted the attention of a man preeminently qualified for detecting and supplying such deficiencies, and whose labours, unparalleled as they are for their scientific importance, are not less valuable from the immense influence they have since exerted upon the practice both of medicine and surgery, might have been anticipated, from the peculiar character of his mind, which was too truly great to think any subject unworthy of his anxious attention which involved the improvement of the art of healing, or the extension of our knowledge of Nature's operations. If it may be stated that the work in question is perhaps the least felicitous effort of this extraordinary genius, and that of which the errors are the most obvious and striking, some apology may be found even for these, in the confined nature of the subject, and especially in the obscure and anomalous structure of the organs of which it treats ; whilst the basis which his experiments and observations have laid for subsequent improvements in our knowledge, both of the physiology and pathology of the teeth, as well as in the treatment of their diseases, constitutes a never-ceasing claim to the gratitude and admiration of every scientific practitioner of dental surgery. If, therefore, it may with truth be said that he was the father of scientific surgery; if he may claim the high distinction of having placed the practice of surgery upon the only solid foundation, that of physiological science, it is no less true of this humble 2 6 HUNTER ON THE TEETH. department than of those more important branches of the art, in which are involved the knowledge and treatment of diseases which stand in immediate connexion with vital organs and functions. It is not uninteresting, even in this work, to trace the peculiarities of his genius, and to watch the workings of his mind in his search after truth, which he pursued with an ingenuousness and candour which have never been surpassed, and rarely, if ever, equalled. It is, indeed, amongst the remarkable characteristics of his reasonings and conclusions,—and this must be the case, too, with all who follow truth with equal zeal and singleness of purpose,—that even his errors arise from that inviolable love of truth, that single aim at establishing, not the dogmas of a favourite theory, but the simple laws of Nature herself, which constitutes one principal charm of his greatest and most important discoveries. This is shown in a very striking point of view by the error, and even inconsistency into which he falls when reasoning on the structure of the teeth. His observations and experiments had shown him that these organs differ in many important respects from the other bones: that the phenomena which these two organs present under comparative circumstances, whether of disease or of experiment, differ in many important respects ; that the teeth are not susceptible of artificial injection; that they cannot restore lost parts ; and many other peculiarities, which led him too hastily to infer that " they are to be considered as extraneous bodies with respect to a circulation through their substance," though the same candour obliges him to confess, in the same sentence, that " they have most certainly a living principle, by means of which they make part of the body, and are capable of uniting with any part of a living body," although the experiments on which he founds the latter proposition, if they prove anything, prove that this union with a living body is effected by means of a vascular continuity. Here, then, is an example of a love of truth for her own sake, so pure, so invulnerable, that not even to avoid the dilemma into which his imperfect reasoning upon these two inconsistent propositions must necessarily force him, will he sacrifice, or modify, or gloss over one tittle of the facts on which they are founded. Whatever errors, however, may have crept into this work from the causes already alluded to, it forms the basis of all that has since been done to improve the knowledge of this branch of practice, and still more remarkably has it proved the foundation of all that is now known on the physiology of the teeth. It must, on the PREFACE. 7 other hand, be conceded to his immediate follower, Dr. Blake, that if he received from Hunter the hints from which his own discoveries were deduced, he has so clearly elucidated what in the former was obscure, so judiciously supplied what was deficient, and so satisfactorily harmonized what appeared to be incompatible or inconsistent, that he well deserves the praise of having contributed more to the right understanding of the subject than any other writer that has ever treated on it either before or since; and his inaugural dissertation (the work, it must be remembered, of a pupil,) contains opinions and statements on the structure, the formation, the growth, and the relations of these organs, which most subsequent writers have done well to copy, and all experimental physiologists have only been able to confirm. The late Joseph Fox, with far less of original talent than his precursor, brought to the practice of his profession a mind well prepared for a diligent, correct, and rational discharge of its duties. If, therefore, his intellectual character were such as precluded him from distinguishing himself in the field of original investigation and discovery, the sober reflective habits of his mind, joined to a regular professional education, enabled him to obtain from an extensive practice such a knowledge of the diseases of these organs, and such well-grounded principles their treatment, as to render his work a very valuable acquisition, not to the professed dentist only, but particularly to the general practitioner; a class of the profession to which his labours were especially devoted, as he lectured on this subject for many years in the theatre of Guy's Hospital. It is, then, to the writers just mentioned that the profession is principally indebted for the knowledge it at present possesses of the anatomy, physiology, and diseases of the teeth. It would be useless here to notice the numerous books which have from time to time appeared, chiefly derived, as they are, from these sources, the merits of which may generally be stated to be in the inverse ratio of their originality. Equally unnecessary is it to enter into an elaborate consideration of the hypotheses which are entertained on the nature of these organs by some of the most distinguished French physiologists. The object of the author in the annotations affixed to the following Treatise has been rather to avail himself of such means as lay before him, to elucidate the text where it is obscure, to correct its errors where subsequent investigations have proved errors to exist, and to add such information on subjects imperfectly treated on as the observations and experience of others, or his own, 8 HUNTER ON THE TEETH. have enabled him to obtain. He has entered upon the task with a degree of diffidence commensurate with the respect which the name of Hunter commands, and with a sacred regard to the same object of general utility as formed the guiding star to the great Original whose work he thus humbly endeavours to illustrate.

New Broad Street, February 1835.

N.B. The Editor's Notes are distinguished from the Author's by being placed within brackets. THE

Before we enter into a description of the teeth themselves, it will be necessary to give an account of the upper and lower jawbones, in which they are inserted ; insisting minutely on those parts which are connected with the teeth, or serve for their motion and action, and passing over the others slightly. The upper jaw is composed of two bones, which generally remain distinct through life. They are very irregular at their posterior and upper parts, sending upwards and backwards a great many processes, that are connected with the bones of the face and skull.* The lower and anterior parts of the upper jaw are more uniform, making a kind of circular sweep from side to side, the convexity of which is turned forwards; the lower part terminates in a thick edge, full of sockets for the teeth. This edge is called in each bone the alveolar process. Behind the alveolar processes there are two horizontal lamellae, which uniting together, form part of the roof of the mouth, which is the partition between the mouth and the nose. This plate, or partition, is situated about half an inch higher than the lower edge of the alveolar process; and this gives the roof of the mouth a considerable hollowness. The use of the upper jaw is to form part of the parietes of the * PI. II. f. 1 & 2. a, a. 3 10 HUNTER ON THE TEETH. mouth, nose, and orbits; to give a basis, or supply the alveolar process, for the superior row of teeth, and to counteract the lower jaw ; but it has no motion itself upon the bones of the head and face.

As the lower jaw is extremely moveable, and its motion is indispensably necessary in all the various operations of the teeth, it requires to be more particularly described. It is much more simple in its form than the upper, having fewer processes, and these not so irregular. Its anterior circular part is placed directly under that of the upper jaw; but its other parts extend further backwards.* This jaw is at first composed of two distinct bones; but these, soon after birth, unite into one, at the middle of the chin. This union is called the symphysis of the jaw. Upon the upper edge of the body of the bone is placed the alveolar process, a good deal similar to that of the upper jaw. The alveolar process extends all round the upper part of the bone, from the coronoid process of one side to that of the other. In both jaws they are everywhere relatively proportioned to the teeth, being thicker behind, where the teeth are larger and more irregular, upon account of the more numerous fangs inserted into them. The teeth that are situated backwards in the upper jaw, have more fangs than those that correspond with them in the lower, and the sockets are accordingly more irregular. The alveolar process of the upper jaw is a section of a larger circle than that of the lower, especially when the teeth are in the sockets. This arises chiefly from the anterior teeth in the upper jaw being broader and flatter than those in the lower.-)- The posterior part of the bone on each side rises almost perpendicularly, and terminates above in two processes ;J the anterior of which is the highest, is thin and pointed, and is called the coronoid process.^ The anterior edge of this process forms a ridge, which goes obliquely downward and forward on the jaw, upon the outside of the posterior sockets.|| To this process the temporal muscle is attached ; and as it rises above the centre of motion, that muscle acts with nearly equal advantage in all the different situations of the jaw. The posterior process, which is made for a moveable articulation with the head, runs upward, and a little backward; is narrower, thicker, and shorter than the anterior; and terminates in an oblong rounded head, or condyle,TI whose longest axis is nearly transverse. The condyle is bent a little forward ; is rounded, or convex, from the fore to the back part; and likewise a little rounded from one end to the other, or from right to left. Its external end is turned •Pl.I.f. 1&2. fPl.I.f.l. J PI. I. f. ae&d.-andPI. II. f. 2. e& f. § PI. II. e, e. || PI. I. f. 2, b. ^ PI. II. f. 2./. J OF THE ALVEOLAR PROCESSES. 11 a little forward, and its internal a little backward ; so that the axes of the two condyles are neither in the same straight line, nor parallel to each other; but the axis of each condyle, if continued backwards, would meet, and form an angle of about one hundred and forty-six deorees; and lines drawn from the symphisis of the chin of the middle of the condyle would intersect their longest axis at nearly right angles.* There are, however, some exceptions, for in the lower jaw of which I have a drawing, the angle formed by the supposed continuation of the two axes, instead of being an angle of one hundred and forty-six degrees, is of one hundred and ten only. The lower jaw serves for a base to support the teeth in the alveolar process during their action on those of the upper jaw in mastication, and to give origin to some muscles that belong to other parts.

Of the Alveolar Processes.

The alveolar processes are composed of two thin bony plates, one external and the other internal. These two plates are at a greater distance from each other at their posterior ends, than at the anterior, or middle part of the jaw. They are united together by thin bony partitions going across, which divide the processes at the anterior part into just as many distinct sockets as there are teeth; but at the posterior part, where the teeth have more than one root or fang, there are distinct cells or sockets lor every root. These transverse partitions are more protuberant than the alveolar plates, and thus add laterally to the depth of the cells, particularly at the anterior part of the jaw. At each partition the external plate of the alveolar process is depressed, so as to form a fluting! round the cells or cavities for the roots of the teeth. This is observable in the whole length of the alveolar process of the upper jaw, and in the fore part particularly of the lower jaw. lhe alveolar processes of each jaw form about one half of a circular, or rather of an elliptical, figure; and at the fore part in the lower iaw they are perpendicular, but project inwards at the posterior part, and describe a smaller circle than the body of the bone upon which they stand, as we shall observe more particularly hereafter, when we come to treat of the jaws of old people. The alveolar processes of both jaws should rather be considered as belonging to the teeth than as parts of the jaws ; for they begin to be formed with the teeth, keep pace with them in their growth and decay and entirely disappear when the teeth fall out; so that if we had no teeth, it is likely we should not only have no socke s, but not even these processes in which the sockets are termed; tor the iaws can perform their motions, and give origin to muscles, without either the teeth or alveolar processes In short, there is such a mutual dependence of the teeth and alveolar processes on * PL II. f. 2- ^l.I.f.2./,/,/,/. 12 HUNTER ON THE TEETH. each other, that the destruction of the one seems to be always attended with that of the other.* In the head of a young subject which I examined, I found that the two first incisor teeth in the upper jaw had not cut the gum, nor had they any root or fang, excepting so much as was necessary to fasten them to the gum, on their upper surface ; and on examining the jaw, I found there was no alveolar process nor sockets in that part. What had been the cause of this I will not pretend to say; whether it was owing to the teeth forming not in the jaw but in the gum, or to the wasting of the fangs. The appearance of the tooth favoured the first supposition, for it was not like those whose fangs are decayed in young subjects, preparatory to the shedding of the teeth ; and as it did not cut the gum, it is reasonable to think it never had any fang. That end from which the fang should have grown was formed into two round and smooth points, having each a small hole leading into the body of the tooth, which was pretty well formed.

Of the Articulation of the Lower Jaw.

Just under the beginning of the zygomatic process of each temporal bone, before the external meatus auditorius, an oblong cavity may be observed, in direction, length, and breadth in some measure corresponding with the condyle of the lower jaw. Before and adjoining to this cavity, there is an oblong eminence, placed in the same direction, convex upon the top, in the direction of its shorter axis, which runs from behind forwards; and a little concave in the direction of its longer axis, which runs from within outwards. It is a little broader at its outer extremitv, as the outer corresponding end of the condyle describes a larger circle in its motion than the inner. The surface of the cavity and eminence is covered with one continued smooth cartilaginous crust, which is somewhat lio-amentous, for by putrefaction it peels off, like a membrane, with the common periosteum. Both the cavity and eminence serve for the motion of the condyle of the lower jaw. The surface of the cavity is directed downward ; that of the eminence downward and backward, in such a manner that a transverse section of both would represent the italic letter S. Though the eminence may, on a first view of it, appear to project considerably below the cavity, yet a line drawn from the bottom of the cavity to the most depending part of the eminence is almost horizontal, and therefore nearl? parallel with the line made by the grinding 'surface!o^ he teethb the upper jaw: and when we consider the articulation fnvthT shall find that these two lines are so nearly p^M^ ^^

* [This observation is strictly correct: however raniHW i\, L sorbed, whether from indigestion, the use of mercury, theSnm^lf IT befCOmes ab" matter, or that affection which is vulgarly termed scurvvTn Se ilTnfcal,cu,ous process never becomes exposed (unless it be a dead portion exfoliati \ a^veo,a« sorption of the bone always keeps pace with that of the gum.] &J> but ab- MOTION IN THE JOINT OF THE LOWER JAW. 13 moves almost directly forwards in passing from the cavity to the eminence; and the parallelism of the motion is also preserved by the shape of an intermediate cartilage. In this joint there is a moveable cartilage, which, though common to both condyle and cavity, ought to be considered rather as an appendage of the former than of the latter, being more closely connected with it, so as to accompany it in its motion along the'common surface of both the cavity and eminence. This cartilage is nearly of the same dimensions with the condyle, which it covers, and is hollowed out on its inferior surface, to receive the condyle. On its upper surface it is more unequal, being moulded to the cavity and eminence of the articulating surface of the temporal bone, though it is considerably less, and is therefore capable of being moved with the condyle, from one part of that surface to another. Its texture is ligarnento-cartilagineous. This moveable cartilage is connected with both the condyle of the jaw and the articulating surface of the temporal bone, by distinct ligaments, arising Irom its edges all round. That by which it is attached to the temporal bone is the most free and loose ; though both ligaments will allow an easy motion of the cartilage on the respective surfaces of the condyle and temporal bone. These attachments of the cartilage are strengthened, and the whole articulation secured, by an external ligament, which is common to both, and which is fixed to the temporal bone, and to the neck of the condyle. On the inner surface of the ligament which attaches the cartilage to the temporal bone, and backwards, in the cavity, is placed what is commonly called the gland of the joint; at least the ligament is there much more vascular than at any other part.

Of the Motion in the Joint of the Lower Jaw.

The lower jaw, from the manner of its articulation, is susceptible of a great many motions. The whole jaw may be brought horizontally forwards, by the condyles sliding from the cavity towards the eminences on each side. This motion is performed^chiefly Z~eel of the lower jaw are brought directly under those of ?he upper, in order to bite or hold anything very fast between

thOr' the condyles only may be brought forwards, while the rest of the iaw is tilted backwards, as is the case when the mouth is open ; for on that occasion the angle of the jaw is tilted backwards and the chin moves downwards, and a little backwards also. In this last motion the condyle turns its face a little forwards; and he centre of motion lies a little below the condyle, in the hne beween it and the angle of the jaw. By such an advancement of he condyles forwards, together with the rotation mentioned, the aperture of the mouth may be considerably enlarged; a circumstance

"ThT^yle. maVSlHur=ely backwards and forwards, 14 HUNTER ON THE TEETH. from the cavity to the eminence, and vice versd; so that while one condyle advances, the other moves backwards, turning the body of the jaw from side to side, and thus grinding between the teeth the morsel separated from the larger mass by the motion first described. In this case the centre of motion lies exactly in the middle between the two condyles. And it is to be observed, that in these slidings of the condyles forwards and backwards, the moveable cartilages do not accompany the condyles in the whole extent of their motion, but only so far as to adapt their surfaces to the different inequalities of the temporal bone: for as these cartilages are hollow on their lower surfaces where they receive the condyle, and on their opposite upper surfaces are convex where they lie in the cavity, but anteriorly, at the root of the eminence, are a little hollowed, if they accompanied the condyles through the whole extent of their motion, the eminences would be applied to the eminences, the cavities would not be filled up, and the whole articulation would be rendered very insecure. This account of the motion of the lower jaw and its cartilages clearly demonstrates the principal use of these cartilages, namely, the security of the articulation, the surfaces of the cartilage accommodating themselves to the different inequalities, in the various and tree motions of this joint. This cartilage is also very serviceable tor preventing the parts from being hurt by the friction; a circumstance necessary to be guarded against where there is so much motion. Accordingly I find this cartilage in the different tribes of carnivorous animals, where there is no eminence and cavity, nor other apparatus for grinding, and where the motion is of the true ginglyrrms kind only. In the lower jaw, as in all the joints of the body, when the motion liVamPn^ lUi $™*f ex}en^ in an7 direction, the muscles and hgaments are strained and the person made uneasy. The state, therefore, into which every joint most naturally falls, especially

KtreJesJLf^u18 n.G\rIy in th* middIe -tate between the extremes of motion; by which means all the muscles and ligaments

he Sft [h *t ^ ■ ^^ * *? that ™<^ and Sly of thTlowir tLZVT frG T m C°ntact' nor are the ™"W™ ot the lowei jaw so far back in the temporal cavities as they can go,

Of the Muscles of the Lower Jaw

■o^it^tifr; fft-ss z:iand i,se of ihe count of the muscles that arc ihe causes?ilTo,fj'^ S°™ aC- There are five pa.rs of muscles, each of .hem canahle „f„rJ • various motions, according to the situation of7h^P ■ Prod"clng they act singly or in conjaaction wkh 0°her, T'JBW'*

than one muscle at a time. Tnu^t^ £ «"S MUSCLES OF THE LOWER JAW. 15 brought to one side, either the masseter, temporal, or pterygoideus internus of the opposite side will not only raise the jaw but bring it to its middle state. It will be necessary in the description of each muscle to give its use in the different situations of the jaw, by which means, after they are all described, their compound actions will be better understood. I shall first describe those which raise the jaw ; then those which give it the lateral motion ; and lastly, those which depress it; proceeding in the order in which they present themselves in dissection. The most superficial is the masseter: it is situated upon the posterior and lower part of the face, between the cheek-bone and angle of the lower jaw, directly before the lower part of the ear. It is a thick, short, complex muscle, and a little flattened : it appears to have two distinct origins, an anterior and outer, and a posterior and inner; but that is owing only to its outer edge at its origin being slit, or double, and the fibres of these two edges having a different course, decussating each other a little. The anterior and outer portion of the muscle begins to rise from a small part of the lower edge of the malar process of the maxillary bone, adjoining to the os make ; and continues its origin all along the lower horizontal edge of this last bone to the angle where its zygomatic process turns up to join that of the temporal bone. The external layer oi fibres in this portion is tendinous at its beginning, while the internal is fleshy. The posterior and inner portion of this muscle begins to rise, partly tendinous and partlv fleshy, from the same lower edge oi the os mate : not where the origin of the other portion terminates, but a little further forwards; and this origin is continued along the lower edge of the zygomatic process of the temporal bone, as iar backwards as the eminence belonging to the articulation oi the lower jaw. , . •, , From this extent of its origin the muscle passes downwards to its insertion into the lower jaw. The anterior external portion is broader at its insertion than at its origin; for it occupies a triangular space of the lower jaw; which, above the angle and on the outside; is about an inch in breadth, but below about an inch and a half from the angle towards the chin. In consequence ot this extent of insertion! the fibres of this portion divaricate very considerably They are mostly fleshy at their insertion, a few only beincr tendinous, particularly those that are inserted backwards. The'posterior and inner portion of the masseter is narrower at its insertion than at its origin : its posterior fibres running forwards as well as downwards, while its anterior run almost directly downvvards It occupies in its insertion the remaining part ol the scabrous surface above the angle of the lower jaw, which lies between the anterior portion and the two upper processes, viz. the condyle and coronoid. As the anterior fibres of this portion rise nn the inside of the posterior fibres of the other portion, and as its posterior fibres run forwards as well as downwards, and its ante- 16 HUNTER ON THE TEETH. rior run almost directly downwards, while the fibres of the other portion radiate both forwards and backwards; these two portions in some measure decussate, or cross one another. The anterior fibres, which run furthest and lowest down, are tendinous at their insertion, while the posterior and shortest are fleshy. The use of the whole muscle is to raise the lower jaw ; and when it is brought forwards, the posterior and inner portion will assist in bringing it a little back: so that this muscle becomes a rotator, if the jaw happens to be turned to the opposite side. We may observe that this muscle is intermixed with a number of tendinous portions, both at its origin and its insertion; which give rise to a greater number of fleshy fibres, and thereby add to the strength of the muscle.

The temporal muscle is situated on the side of the head, above and a little before the ear. It is a flat and radiated muscle; broad and thin at its origin ; narrow and thick at its insertion; and covered with a pretty strong fascia above the jugum. This fascia is'fixed to the bones round the whole circumference ol the origin of the muscle. Above, it is fixed to a smooth white line, which is observable upon the skull, extending from a little ridge on the lateral part of the os frontis, continued across the parietal bone and making a turn towards the mammillary process. It is fixed below to the ridge where the zygomatic process begins, just above the meatus auditorius; then to the upper edge of the zygomatic process itself, and anteriorly to the os mala This adhesion above before, and behind, describes, as it were, the circumference of the origin of the temporal muscle. This muscle arises from all the bones of the side of the head that are within the hue for insertion of the tendinous fascia! viz f on the lower and lateral part of the parietal bone, from al the squa mous portion ot the temporal bone, from the lower and lateral part of the os frontis, from the temporal process of the os sphenoide often from a process at the lower part of this surface»Twhirh portion, however is often common t/this m I I e(p n goideus externus), and from the posterior surface of the os mate: outwardly, it arises from the inner surface of the ,„ and from the whole inner surface of the fascia At IV 5 ' from the jugum it is not to be distinguished from ^l « f being there in fact one and the same nC c an7?J^7h ^ seter is no more than a continmtinn J,i lndeed the masedge of the jugum, and Zth Voner v enn'T.0"** U"der the same, both as' to its origin and iStfo and f reCk°ned ^ its use also. mseiuon, and in some measure in The origin is principally fleshy and th« ™ i thence downward] and'a Imle for^ar us, %>£%£ Zi7 '^ a thin middle tendon: after which the mvsZZste^XZ INTERNAL AND EXTERNAL PTERYGOID MUSCLES. 17

the inside of the jugum, and is inserted into the coronoid process of the lower jaw, on both sides tendinous and fleshy, but principally tendinous. It reaches further down upon the inside of the coronoid process than upon the outside, the insertion being continued as low down as the body of the bone. The posterior and inferior edge of this muscle passes over the root of the zygomatic process of the temporal bone as over a pulley, which confines the action of the muscle to that of raising the lower jaw more than if its fibres had passed in a direct course from their origin to their insertion. The use of the temporal muscle, in general, is to raise the lower iaw • and as it passes a little forwards to its insertion, it must bring the condyle at the same time backwards, and so counteract the pterveoideus externus of the opposite side ; and if both muscles act, they counteract both the pterygoids, by bringing back the whole of the jaw.

Of the Internal Pterygoid Muscle. The internal pterygoid muscle is situated upon the inside of the lower iaw, opposite to the masseter. It is a strong short muscle, a little flattened, especially at its insertion. It arises tendinous^and fleshy from the whole internal surface of the external ala oi the sphenoid bone; from the external surface of the internal ala, near its bottom; from that process of the os palati that makes part ot the fossa pterygoidea; likewise from the anterior rounded surtace of that process where it is connected to the os maxillare supenus. From thence the muscle passes downwards, a little outwards ana backwards, and is inserted, tendinous and fleshy, into the inside ot the lower jaw, from the angle up almost to the g™ve f°r.™ admission of the maxillary nerve, where the surface of the bone is remarkably scabrous. . . The use of this muscle is to raise the lower jaw ; and from is direction, one would suspect that it would bring the condyle a littte forwards; but this motion is contrary to that of the lowei jaw, tor it is naturally brought back when raised.

Of the External Pterygoid Muscle.

The external pterygoid muscle is situated immediately between the external surface of the external ala of the pterygoid process and the condyle of the lower jaw, lying, as it were, horizontally afonthe basis of the skull. It is somewhat radiated in some bodies broad at the origin, and small at the insertior>; bu the greater part of it forms a round strong fleshy belly, so that the nirt that makes it of the radiated kind is thin. , floo. P The th ck and ordinary portion of it arises tendinous and fleshy, from almost the whole external surface of the external ala of the 18 HUNTER ON THE TEETH. pterygoid process of the sphenoid bone, excepting a little bit of the root at the posterior edge; and towards the lower part it arises a little from the inner surface of that ala. The thin portion arises from a ridge of the sphenoid that is continued from the process towards the temple, just behind the foramen lacerum infcrius, which terminates in a little protuberance. This origin is sometimes wanting, and in that case the temporal muscle arises from that protuberance ; and very often this origin is common to both. These two origins of this muscle are sometimes so much separated as to make it a biceps. From these origins the muscle passes outwards and a little backwards, converging; that is, the superior fibres passing outwards and backwards, and a little downwards; while the inferior or larger portion of it passes a little upward. It is inserted, tendinous and fleshy, into a depression on the anterior part of the condyle and neck of the lower jaw, upon the inside of that ridge which is continued from the coronoid process; a little portion is likewise inserted into the anterior part of the moveable cartilage of the joint. When this muscle acts singly, it is a rotator; for it brings the condyle of the jaw forwards, and likewise the moveable cartilage, which throws the chin to the opposite side; but if it acts in conjunction with its fellow of the opposite side, instead of being turned to one side, the whole jaw is brought forwards, and thus these counteract the temporal, &c. These two muscles generally act alternately; and when they do so, one acts at the time of depression, the other at the time of elevation ; so that these muscles act both when the lower jaw is raised and when it is depressed ; although they do not assist in this act.

Of the Superior Digastric Muscle.

The digastricus is situated immediately under and a little upon the inside of the lower jaw, and exterior to the fauces, extending from the mastoid process to the chin, nearly along the angle made by the neck and chin, or face. The name of this muscle expresses its general shape, as it has two fleshy bellies, and of course a middle tendon. Yet some of its anterior belly does not arise from the tendon of the posterior, but from the fascia which binds it to the os hyoides. These two fleshy bellies do not run in the same ine,but form.an angle, just where the tendon runs into the anterior belly; so that this tendon seems rather to belong to the posterior, which is the thickest and longest. This muscle arises from the sulcus made by the inside of the mastoid process, and a ridge upon the temporal bone, where it is united with the os occipitis. The extent of this origin is about an inch; it is fleshy upon its outer part, viz. that from the mastoid process, and tendinous on the inside from the ridge. From its SUPERIOR DIGASTRIC MUSCLE. 19 origin it passes forwards, downwards, and a little inwards, much in the direction of the posterior edge of the mammillary process, and forms a round tendon, first in its centre and upper surface. This tendon passes on in the same direction; and when got near the os hyoides, commonly perforates the anterior end of the stylohyoideus muscle. From the lower edge of this tendon some fibres seem to go off, which degenerate into a kind of fascia, which binds it to the os hyoides; while some go across the lower part of the mylo-hyoideus, and joining their fellows on the opposite side, bind the os hyoides by a kind of belt. At this part the tendon becomes a little broader, makes a turn upwards, inwards, and forwards, and giving origin to the anterior belly, passes on, in the same direction, to the lower part of the chin, where it is inserted, tendinous and fleshy, into a slight depression on the under and a little on the posterior part of the lower jaw, almost contiguous to its fellow. Besides the attachment of the middle tendon to the os hyoides, there is a ligamentous binding, which serves in some measure as a pulley. This is more marked in some subjects than in others; and this depends on the strength of the tendinous expansion which binds the tendon of the digastricus to the os hyoides. When we say that these parts are attached to the os hyoides, we do not mean that they can be traced quite into it, like some other tendons in the body; but the os hyoides seems to be the most fixed point of attachment. Very often we find two anterior bellies to each muscle: the uncommon one, which is the smallest, does not pass to the chin, but joins with a similar portion on the other side, in a middle tendon, which is often fixed to the os hyoides. At other times we find such a portion on one side only, in which case it is commonly fixed to the middle tendon of the mylo-hyoideus. The use of these muscles with regard to the lower jaw is principally to depress it; but according as one acts a little more forcibly than the other, it thereby gives the jaw a small rotation, and becomes in that respect a kind of antagonist to the pterygoideus externus. Besides depressing the lower jaw, when we examine the dead body, they would appear to raise the larynx. But although they have this effect, a proper attention to what happens in the living body will probably show that their principal action is to depress the lower jaw, and that they are the muscles commonly employed for this purpose. Let a finger be placed on the upper part of the sterno-mastoideus muscle, just behind the posterior edge of the mastoid process, about its middle, touching that edge a little with the finger; then depress the lower jaw ; and the posterior head of the digastricus will be felt to swell very considerably, so as to point out the direction of the muscle. In this there can be no deception, for there is no other muscle in this part that has the same direction; and those who are of opinion that the digastricus does not depress the lower jaw will more readily allow this when they are told that we find the same head of the muscle act in deglutition? but not with a force equal to that which it exerts in depressing the 20 HUNTER ON THE TEETH. lower jaw. Further, if the sterno-hyoidei, sterno-thyroidei, and costo-hyoidei, acting at the same time with the mylo-hyoidei and genio-hyoidei, assisted in depressing the jaw, the os hyoides and thyroid cartilage would probably be depressed as the bellies of the sterno-hyoidei and of the other lower muscles are by much the longest; but, on the contrary, we find that the os hyoides, with the thyroid cartilage, is a little raised in the depression of the jaw, which we may suppose to be done by the anterior belly of the digastricus; and, secondly, if these muscles were to act to bring about this motion of the jaw, these parts would be brought forwards, nearer to the straight line between the chin and sternum, which is not the case in this action; whereas we find it to be the case in deglutition, in which these evidently act. By applying our fingers upon the genio-hyoideus and mylo-hyoideus, near the os hyoides, between the two anterior bellies of the digastricus (not near the chin, where the action of these two bellies may occasion a mistake), we find these muscles quite flaccid, which is not the case in deglutition nor in speaking, in which they certainly do act; nor do we find the muscles under the os hyoides at all affected, as they are in the motion of the larynx. It has been observed that when we open the mouth, while we keep the lower jaw fixed, the fore part of the head or face is necessarily raised. Authors have been at a good deal of pains to explain this. Some of them considered the condyles of the jaw as the centre of motion. But if this were the case, that part of the head where it articulates with the spine, and consequently the whole body, must be depressed in proportion as the upper jaw is raised, which is not true in fact. Others have considered the condyles of the occiput as the centre of motion; and they have conceived the extensor muscles of the head to be the moving powers. The muscles which move the head in this case are pointed out by two circumstances which attend all muscular motion; in the first place, all actions of our body have muscles immediately adapted to them; and, secondly, when the mind wills any particular action, its power is applied by instinct to those muscles only which are naturally adapted to that motion; and further, the mind being accustomed to see the part move which is naturally the most moveable, attends to its motion in the volition, although it be in that instance fixed, and the other parts of the body move towards it; and although the other parts of the body might be brought towards it by other muscles, and would be so if the mind intended they should come towards it, yet these muscles are not brought into action. Thus, the flexors of the arm commonly move the hand to the body, but if the hand be fixed, the body is moved by the same muscles to the hand. In this case, however, the mind wills the motion of the hand towards the body, and brings the flexors into action; whereas, if it wished to bring the body towards the hand, the muscles of the fore part of the body would be put into action, and this would produce the same effect. ^ • STRUCTURE OF A TOOTH—THE ENAMEL. 21 To apply this to the lower jaw: when we attempt to open the mouth while the lower jaw is immoveable, we fix our attention upon the very same muscles (whatever they are) which we call into action when we depress the lower jaw, and we find that we act with the very same muscles; for our mind attends to the depressing of the jaw, and not the raising of the face, and under such circumstances the mouth is actually opened. We find then by these means the head is raised; and the idea that we have of this motion is the same that we have in the common depression of the jaw; and we should not know, except from circumstances, that the jaw was not really depressed; we find also at this time that the extensors of the head are not in action. On the contrary, when the jaw is fixed in the same situation, if we have a mind to raise the head or upper jaw, which of course must open the mouth, we fix our attention to the muscles that move the head backwards without having the idea of opening our mouth; and at this time the extensors of the head act. This plainly shows that the same muscles which depress the jaw when moveable, must raise the head when the jaw is kept fixed. This is a proof too that there are no other muscles employed in depressing the lower jaw than what will raise the head under the circumstances mentioned. This will further appear from the structure of the parts; wherein four things are to be considered, viz. the articulation of the jaw; the articulation of the head with the neck; the origin and the insertion of digastric muscle. Suppose the upper jaw to be fixed, and the lower jaw to be moveable on the condyle, if the digastric contracts, its origin and insertion will approach towards one another; in which case it is evident that the lower jaw will move downwards and backwards. But if the lower jaw be fixed, as in the case supposed, and the vertebra also the condyle will move upwards and forwards upon the eminence in the joint, the fore part of the head will be pushed upwards and backwards by the condyle, and the hind part of the head will be drawn down; so that the whole shall make a kind of circular motion upon the upper vertebrse; and the digastric muscle, pulling the hind part of the head towards the lower jaw, and at the same time pushing up the condyles against the fore part of the head, acquires by this mechanism a very considerable additional power.

Of the Structure of a Tooth; and, first, of the Enamel.

A tooth is composed of two substances, viz. enamel and bone. The enamel, called likewise the vitreous or cortical part, is found only upon the body of the tooth, and is there laid all round on the outside of the bony or internal substance.* It is by far the hardes nart of our body ; insomuch that the hardest and sharpest saw will scarce make an impression upon it, and we are obliged to use a hie * PI. 111. f. 15, 16, 18. 4 22 HUNTER ON THE TEETH. in dividing or cutting it. When it is broken it appears fibrous or striated, and all the fibres or striae are directed from the circumference to the centre of the tooth.* This in some measure prevents it from breaking in mastication, as the fibres are disposed in arches, and also keeps the tooth from wearing down, as the ends of the fibres are always acting on the food. The enamel is thickest on the grinding surface and on the cutting edges or points of the teeth, and becomes gradually thinner on the sides as it approaches the neck, where it terminates insensibly, though not equally low, on all sides of the teeth.f On the base or grinding surface it is of a pretty equal thickness, and therefore is of the same form with the bony substance which it covers.J It would seem to be an earth united with a portion of animal substance, as it is not reducible to quick-lime by fire till it has first been dissolved in an acid. When a tooth is put into a weak acid, the enamel to appearance is not hurt; but on touching it with the fingers it crumbles down into.a white pulp. The enamel of teeth, exposed to any degree of heat, does not turn to lime: it contains animal mucilaginous matter; for when exposed to the fire it becomes very brittle, cracks, grows black, and separates from the inclosed bony part of the tooth. It is capable, however, of bearing a greater degree of heat than the bony part, without becoming brittle and black.§ This substance has no marks of being vascular and of having a circulation of fluids: the most subtile injections we can make never reach it; it takes no tinge from feeding with madder, even in the youngest animals ; and, as was observed above, when soaked in a gentle acid there appears no gristly or fleshy part with which the earthy part had been incorporated.|| We shall speak of the use and formation of the enamel hereafter, when they will be better understood.1T

* PI. III. f. 22, 23, 24. -J- ibid ± j.., ao§thFT th'S ^cumstancLp; w^ can show the enamel better by burning a tooth as the bony part becomes black sooner than the enamel. The method* of bu ningand showing them after they are burnt, is as follows : Let oSal'of a tooth be filed away, from one end to another, then burn it aentlv in th/fi ! • ?<■,,?

|j In all these experiments I never could observe tn*t ti,„ „ i • , least tinged, either in the growing or formed tooU Thil I Tm?l ?M '" th? were the earth more fully depurated, or™,aiSff T u0ks aS ,f the enamel such a manner as not to &l0£ ihegMsnrttLZV^M* C°mm°n jUiceS j" may not be amiss to remark, that the names cHven f. f' l° paSS> Here U gluten, &c, are not in the least expressive of thl ?,ammal substance, such as such thing as glue in an animal till it has either umWlng meant' for there is no or been changed by heat. And here, too I wish ir f°"k * Putrefactive process not consider earth as any part of an animal or th»t"• , underst°od that I do animal substance. ' u,a'" makes up any part of an «T [The structureof the enamel is perfectly crystalline tu in appearance, and placed parallel to each other =u it*. lhf; crystals are fibrous ' 3t r'Sht anSles with the surface BONY PART OF A TOOTH. 23 Of the Bony Part of a Tooth.

The other substance of which a tooth is composed is bony, but much harder than the most compact part of bones in general. This substance makes the interior part of the body, the neck, and the whole of the root of a tooth. It is a mixture of two substances, viz. calcareous earth and an animal substance, which we might suppose to be organized and vascular. The earth is in very considerable quantity : it remains of the same shape after calcination, so that it is in some measure kept together by cohesion; and it is capable of being extracted by steeping in the muriatic and some other acids. The animal substance, when deprived of the earthy part by steeping in an acid, is more compact than the same substance in other bones, but still is soft and flexible. That part of a tooth which is bony has nearly the same form as a complete tooth; and hence, when the enamel is removed, it has the same sort of edge or points as the enamel itself. We cannot by injection prove that the bony part of a tooth is vascular; but from some circumstances it would appear that it is so; for the fangs of teeth are liable to swellings, seemingly of the spina ventosa kind, like other bones, and they sometimes anchylose with the socket by bony and inflexible continuity, as all other contiguous bones are apt to do. But there may be a deception here, lor the swellino- may be an original formation, and the anchylosis may arise from the pulp, upon which the tooth is formed, being united with the socket. The following considerations would seem to show that the teeth are not vascular : first, I never saw them injected in any preparation, nor could I ever succeed in any attempt to inject them, either in young or old subjects, and therefore believe that there must have been some fallacy in the cases vyhere they have been said to be injected. Secondly, we are not able to trace any vessels going from the pulp into the substance of a new-formed tooth ; and whatever part of a tooth is formed, it is always completely formed which is not the case with other bones. But, reasoning from analogy, we have a still more convincing proof in the effect of madder. Take, for example, any young animal, as a pig, and feed it with madder for three or four weeks; then kill the animalarid upon examination you will find the following appearances : first, if this animal had some parts of its teeth formed before

r,, ,„„.,,:.. nf tliP tooth with which their inner terminations are placed in cttacu" ^ is° truetattereTa trace of animal matter in this substance, according to the following analysis by Berzelius : Phosphate of lime..........8;>'3 Fluate of lime............ 3-2 Carbonate of lime ........... 8* Phosphate of magnesia........ I'5 Soda and muriate of soda...... 1* Animal matter and water....... 1' 100-] 21 HUNTER ON THE TEETH. the feeding with madder, those parts will be known by their remaining of the natural colour; but such parts of the teeth as were formed while the animal was taking the madder will be found to be of a red colour. This shows that it is only those parts that were formed while the animal was taking the madder that are dyed; for what were already formed will not be found in the least tinged. This is different in all other bones, for we know that any part of a bone which is already formed is capable of being dyed with madder, though not so fast as the part that is forming; therefore, as we know that all other bones when formed are vascular, and are thence susceptible of the dye, we may readily suppose that the teeth are not vascular, because they are not susceptible of it after being once formed. But we shall carry this still further: if you feed a pig with madder for some time, and then leave it off for a considerable time before you kill the animal, you will find the above appearances still subsisting, with this addition, that all the parts of the teeth which were formed after leaving off feeding with the madder will be white. Here then in some teeth we shall have white, then red, and then white again ; and so we shall have the red and white colour alternately ihrough the whole tooth. This experiment shows that the tooth, once tinged, does not lose its colour: now as all other bones that have not been tinged lose their colour in time, when the animal leaves off feeding with madder (though very slowly), and as that dye must be taken into the constitution by the absorbents, it would seem that the teeth are without absorbents as well as other vessels. This shows that the growth of the teeth is very different from that of other bones. Bones begin at a point, and shoot out at their surface, and the part that seems already formed is not in reality so, for it is forming every day by having new matter thrown into it, till the whole substance is complete ; and even then it is constantly changing its matter. Another circumstance in which teeth seem different from bone and a strong circumstance in support of their having no circulation in them, is, that they never change by age, and seem never to undergo any alteration when completely formed but by abrasion they do not grow softer, like the other bones, as we find in ome cases where the whole earthy matter of the bones has been takTn into the constitution. miteii From these experiments it would appear that the teeth are to be considered as extraneous bodies, with resoect tn «"-,?• through their substance; but they have mtscertaLv7 ^ principle, by which means they make pa^of the S3? » \ § capable of uniting with any U of Pa tbg body ^ wdl ^ explained hereafter. It s to be ohsprv^ *u ♦ a-y' ■ m be whole body hare less influence upo,htee,Iff"0".3,, °f the of the body. Thus, io child™ affected w?t,£rAL^,^ grow equally well as in health, though all thf o tTot 'at S CAVITY OF THE TEETH. 25 affected; and hence their teeth being of a larger size in proportion to the other parts, their mouths are protuberant.*

Of the Cavity of the Teeth.

Every tooth has an internal cavity, which extends nearly the whole length of its bony part.f It opens or begins at the point of the fang, where it is small; but in its passage it becomes larger, and ends in the body of the tooth;J the cavity at this end is exactly of the shape of the body of the tooth to which it belongs; and in

* [As the arguments which are here adduced against the vascularity of the teeth are wholly insufficient, and in many respects inconsistent with each other, it will be useful to examine into the true bearing of the observations *on which Ihey are founded. The failure of all attempts to inject the substance of the teeth, when even the finest of the matters usually employed for filling the minute branches of arteries in other structures of the body, can scarcely be considered as conclusive, since the colouring matter is, in all of them, too dense and coarse to pass into the vessels of many other parts, which, though in the healthy condition they do not convey red blood, yet in a state of inflammation, become evidently injected with red particles. I have, however, on another occasion, alluded to two very conclusive facts, which appear unanswerably to prove the vascularity of the teeth. One is the occasional occurrence of red patches in the otherwise healthy bony structure of a tooth when much inflamed, discoverable by breaking or sawing asunder the body of the tooth immediately after extraction. The other, the injection of a tooth with bile in cases of jaundice, of which I have seen more than one example. In the former instance, the red patches are of rather a bright colour, until they become dull and obscure by time; and in the latter the whole substance of the tooth is imbued with a bright yellow colour. The experiments on madder would be far from conclusive on the point at issue, even were the details more complete. In the absence, however, of all information respecting the duration of each experiment, and especially the period which elapsed after the madder had been discontinued before the animal was killed, it would be futile to combat the conclusions which Hunter has deduced from them. Thus deficient, they only prove that the more highly organized bones, as might be expected, lose the colouring matter of the madder by absorption sooner than the teeth. The paragraph in which the results are summed up is perhaps as characteristic of the peculiar tendencies of Hunter's mind as any that can be found in his works. Concluding, from the failure of his experiments with madder, and from other peculiarities, that the teeth are devoid of a circulation through their substance, and therefore to be so far considered as extraneous bodies, his intense love of truth, which never suffered him even to escape from a dilemma by its slightest sacrifice, forces him to confess the existence of a living principle, because** he found, from the result of other experiments, that they " were capable of uniting with any part of a living body." Instead, therefore, of endeavouring to render his theory consistent with itself, by disguising or perverting one of the two incompatible conclusions to which his observations had forced him, he adopts them both, and is thus driven to the inference, that an organ can, at the same time, be " an extraneous body," and yet possess " a living principle," and be " capable of uniting with any part of a living body." The truth appears to be, that the teeth are truly organized bodies, having nerves and absorbent and circulating vessels, but possessing so low a degree of living power, and so dense a structure, as to exhibit phenomena, both in their healthy and diseased condition, whieh are very dissimilar from those which are observed in true osseous structures.] f PI. III. f. 1, 2, 3, &c. t Ibid. 4* 26 HUNTER ON THE TEETH. general it may be said that the whole of the cavity is nearly of the shape of the tooth itself, larger, that is, in the body of the tooth, and thence gradually smaller to the extremity of the fang; simple where the tooth has but one root,* and in the same manner compounded when the tooth has two or more fangs.f This cavity is not cellular, but smooth in its surface : it contains no marrow, but appears to be filled with blood-vessels,J and, I suppose, nerves, united by a pulpy or cellular substance. The vessels are branches of the superior and inferior maxillaries, and the nerves must come from the second and third branches of the fifth pair. By injections we can trace the blood-vessels distinctly through the whole cavity of the tooth; but I could never trace the nerves distinctly even to the beginning of the cavity.

Of the Periosteum of the Teeth.

The teeth, as we have observed, are covered by an enamel only at their bodies; but at their fangs they have a periosteum, which, though very thin, is vascular, and appears to be common to the tooth which it incloses, and the socket, which it lines as an investing internal membrane. It covers the tooth a little beyond the bony socket, and is there attached to the gum.§

Of the Situation of the Teeth.

The general shape and situation of the teeth are obvious. The opposition of those of the two jaws, and the circle which each row describes, need not be particularly explained, as they may be very well seen in the living body, and may be supposed to be already understood from what has been said of the alveolar processes We may just observe, with regard to the situation of the two rows, that when they are in the most natural state of contact, the teeth of the upper jaw project a little beyond the lower teeth, even at the sides of the jaws, but still more remarkably at the fore part where, in most people, the upper teeth lie before those of the lower' jau ;|| and a the lateral part of each row the line or surface of contact is hollow from behind forwards in the lower jaw, and in the same proportion it is convex in the upper iaw 1 J 1 he edge of each row is single at the fore part of the iaw, • but as the teeth grow thicker backwards, it there ^HtsInto an Internal

* PI. III. f. 4, 5, 6, 7. t PI III f 1 2 § [The periosteum can hardlv be said mh«™™l' , + Pl' V- f- 7> 8- It is, in fact, continued from tL external sn^? 1° th,e t00lh and lhe so<*et. socket, and then reflected over the surface of th! areolar process into the be removed from a dead body, it will be fnnnH V j hus' if a healthy tooth periosteum, and the alveolar cavitv will also nA°* W1.th an extremely thin structure. Probably when inflammation has once7x^7'" ""^ b* a simi,ar ln 5 piTST' the two ,ayerVb TbT pe--emT^nrdTs,derable degree NUMBER OF THE TEETH. 27 and external edge. The canine tooth, which we shall call cuspidatus, is the point from which the two edges go off, so that the first grinder, or what we shall call the first bicuspis, is the first tooth that has a double edge.*

Of the Number of the Teeth.

Their number in the whole, at full maturity, is from twenty-eight to thirty-two: I once saw twenty-seven only; never more than thirty-two. Fourteen of them are placed in each jaw when the whole number is no more than twenty-eight, and sixteen when there are thirty-two. If the whole be twenty-nine or thirty-one in number, the upper jaw sometimes, and sometimes the lower, has one more than the other ; and when the number is thirty, I find them sometimes divided equally between the two jaws; and in other subjects sixteen of them are in one jaw and fourteen in the other. In speaking of the number of teeth, I am supposing that none of them have been pulled out, or otherwise lost; but that there are from eight to twelve of those large posterior teeth, which I call grinders, and that they are so closely planted as to make a continuity in the circle; and in this case, when the number is less than thirty-two, the deficiency is in the last grinder. The teeth differ very much in figure from one another, but those on the right side in each jaw resemble exactly those on the left, so as to be in pairs; and the pairs belonging to the upper jaw nearly resemble the corresponding teeth of the lower jaw in situation, figure, and use.f Each tooth is divided into two parts, viz. first, the body, or that part of it which is the thickest, and stands bare beyond the alveoli and gums ; secondly, the fang, or root, which is lodged within the gum and alveolar process : and the boundary between these two parts, which is grasped by the edge of the gum, is called the neck of a tooth. The bodies of the different teeth differ very much in shape and size, and so do their roots. The difference must be considered hereafter. The teeth of each jaw are commonly divided into three classes, viz. Incisors, Canine, and Grinders ; but from considering some circumstances of their form, growth, and use. I choose to divide them into the four following classes, viz. Incisores, commonly called fore teeth; Cuspidati, vulgarly called canine; Bicuspides, or the first two grinders ; and Molares, or the last three teeth. The number of each class irreach jaw, for the most part is four incisores, two cuspidati, four bicuspides, and four, five, or six molares. There is a regular gradation, both in growth and form, through these clnsses, from the incisores to the molares; in which respect the cuspidati are of a middle nature between the incisores and bicuspides, just as the last-mentioned are intermediate between the "PI. II. f. 1,2. f PI. I. & II, and PI, III. row 1, 2, 3, 4. 28 HUNTER ON THE TEETH. cuspidati and molares: consequently the incisores and molares are the most unlike in every circumstance.*

The incisores are situated in the anterior part of the jaw ; the others more backwards on each side, in the order in which we have named them. The bodies of the incisores are broad, having two flat surfaces, one anterior, the other posterior. These surfaces meet in a sharp cutting edge. The anterior surface is convex in every direction, and placed almost perpendicularly; and the posterior is concave and sloping, so that the cutting edge is almost directly over the anterior surface.f These surfaces are broadest, and the tooth is thinnest, at the cutting edge or end of the tooth, and thence they become gradually narrower and the root thicker towards the neck, where the surfaces are continued to the narrowest side or edge of the fang. The body of an incisor, in a side view, grows gradually thicker or broader from the edge of the tooth to its neck; and these coincide with the flat or broad side of the fang : so that when we look on the fore or back part of an incisor, we observe it grows constantly narrower from its cutting edge to the extremity of its fang. But in a side view it is thickest or broadest at its neck, and thence becomes gradually more narrow, both to its cutting edge and to the point of Tts fang.} The enamel is continued further down, and is thicker on the anterior and back part of the incisores than on their sides, and is even a little thicker on the fore part than upon the back part of the tooth. If we view them laterally, either entire or when cut down through the middle, but especially in the latter case, it would seem as if the fang was driven like a wedge into and had split the body or enamel of the tooth.§ They stand almost perpendicularly heir bodies turned a little forwards. Their fangs are much shorter than those of the cuspidati, but pretty much of the same length with all the other teeth of this jaw.|| a

fir?, ^h UP?ei" J*,w-they a[e bLroader and thicker, especially the two first, heir length is nearly the same with those of the lower iaw. they stand a little obliquely, with their bodies turned much more

Sunder jaw eSPeCially'} ^ ^ Senera1^ fal1 0Ver *°"'* The two first incisores cover the two first and half of the second of the lower jaw, so that the second incisor of the upper jaw covers we*Sto^d^ptU- are .*h aTare ju'st S£i££ f^ ^ *»* f™» which in the least worn down by mastication.3 0urTellHpfe p' ^ ?0t ^^ from the lower jaw; and the difference between E and ,hh class ls taken classes m the upper jaw immediately follows that description corresPonding t PL HI. t Ibid. § lbid. f. 18< V n' THE CUSPIDATUS. 29 half of the second incisor and more than half of the cuspidatus of the under jaw.* The edges of the incisores, by use and friction, in some people become blunt and thicker; and in others they sharpen one another, and become thinner.

The cuspidatus is the next after the incisores in each jaw, so that there are four of them in all. They are in general thicker than the incisores, and considerably the longest of all the teeth.f The shape of the body of the cuspidatus may be very well conceived by supposing an incisor with its corners rubbed off, so as to end in a narrow point instead of a thin edge;} and the fang differs from that of an incisor only in being much larger.§ The outside of the body of a cuspidatus projects most at the side next the incisores, being there more angular than anywhere else. The enamel covers more of the lateral parts of these teeth than of the incisores. They stand perpendicularly, or nearly so, projecting further out in the circle than the others, so that the two cuspidati and the four incisores often stand almost in a straight line, especially in the lower jaw. This takes place only in adults, and in them only when the second teeth are rather too large for the arch of the jaw; for we never find this when the teeth are at any distance from one another, or in young subjects. Their points commonly project beyond the horizontal plane formed by the row of teeth, and their fangs run deeper into the jaws, and are oftener a little bent. In the upper jaw they are rather longer, and do not project much bevond the circle of the adjacent teeth ; and in this jaw they are not placed vertically, their bodies being turned a little forwards and outwards. When the jaws are closed, the cuspidatus of the upper jaw falls between and projects a little over the cuspidatus and first bicuspis of the lower jaw. When they are a little worn down by use, they commonly first take an edge somewhat like a worn incisor, and afterwards become rounder. The use of the cuspidati would seem to be to lay hold of substances, perhaps even living animals: they are not formed for dividing, as the incisores are, nor are they fit for grinding. We may trace in these teeth a similarity in shape, situation, and use, from the most imperfectly carnivorous animal, which we believe to be the human species, to the most perfectly carnivorous, viz. the lion. || * PI I f 1 f PI. II. f. 4; Plate III. row 1, b. ± pi.' ii. ir. 1, at bb. § PI. II. f. 4. II [That our conclusions as to the functions of an organ as it exists in man, when drawn exclusively from analogous structures in the lower animals, will frequently prove erroneous, is strikingly shown in these observations on the use 30 HUNTER ON THE TEETH. Of the Bicuspides.

Immediately behind the cuspidati, in eaoh jaw, stand two teeth, commonly called the first and second grinders, but which, for reasons hinted at above* I shall suppose to constitute a particular class, and call them bicuspides. These (viz. the fourth and fifth tooth from the symphysis of the jaw) resemble each other so nearly that a description of the first will serve for both. The first indeed is frequently the smallest, and has rather the longest fang, having somewhat more of the shape of the cuspidatus than the second. The body of this tooth is flattened laterally, answering to the flat side of the fang. It terminates in two points, viz. one external and one internal. The external is the longest and thickest; so that on looking into the mouth from without, this point only can be seen, and the tooth has very much the appearance of a cuspidatus, especially the first of these teeth. The internal point is the least, and indeed sometimes so very small that the tooth has the greatest resemblance to a cuspidatus in any view.* At the union of the points the tooth is thickest, and thence it loses in thickness, from side to side, to the extremity of the fang, so that the fang continues pretty broad to the point, and is often forked there. All the teeth hitherto described often have their points bent, and more particularly the cuspidati. The enamel passes somewhat further down externally and upon the inside, than laterally; but this difference is not so considerable as in the incisores and cuspidati; in some, indeed, it terminates equally all round the tooth. They stand almost perpendicularly, but seem to be a little turned inwards, especially the last of them. In the upper jaw they are rather thicker than in the lower, and are turned a very little forwards and outwards. The first in the upper jaw falls between the two in the lower, the second falls between the second and the first grinder; and both project over those of the lower jaw, but less than the incisores and cuspidati. The bicuspides, and especially the second of them, in both jaws, are oftener naturally wanting than any of the teeth, except the dentes sapientiae; hence we might conjecture that they are less useful; and this conjecture appears less improbable when we consider that

of the cuspidatus. The simple and obvious use of this tooth, in the human species, is to tear such portions of food as are too hard or touffh to be divided by the incisores ; and we frequently find it even far more defeloned in animals which are known to be exclusively fruerivorous. Not onlv \Jul f ! animals unadapted for such an object as that°ass gned. tTit in11 "tl*tTTT "^ analogous or other ground for supposing that man J J ? tC,f' but there 1S "° the pursuit and capture of livinTprey0. Hi Tnto^™81™"' COnStructed for structure of the mouth would render this imposs L LV^1 P0Slt,?nr and the Hunter, and the possession of so perfect an Emt i aVET u ^ I7 necessity of his ever employing any other orsan for\h« ? obviates the holding food of whatever description.] g he PurP0Se of seizing or * PI. II. f. 1,2, c c. THE GRINDERS. 31 in their use they are of a middle nature between cutters and grinders, and that in most animals, so far as 1 have observed, there is a vacant space between the cutters and grinders. I have also seen a jaw in which the first bicuspis was of the same shape and size as a grinder, and projected, for want of room, between the cuspidatus and second bicuspis. These and the grinders alter very little in shape on their grinding surfaces by use; their points only wear down and become obtuse.

In describing the grinders we shall first consider the first and second conjointly, because they are nearly the same in every particular, and then give an account of the third or last grinder, which differs from the former in some circumstances. The two first grinders differ from the bicuspides principally in being much larger, and in having more points upon their body and more fangs.* The body forms almost a square, with rounded angles. The grinding surface has commonly five points, or protuberances, two of which are on the inner, and three on the outer part of the tooth ; and generally some smaller points at the roots of these larger protuberances. These protuberances make an irregular cavity in the middle of the tooth. The three outer points do not stand so near the outer edge of the tooth as the inner do on the inside; so that the body of the tooth swells out more from the points, or is more convex, on the outside. The body towards its neck becomes very little smaller, and there divides into two flat fangs, one forwards the other backwards, with their edges turned outwards and inwards, and their sides consequently forwards and backwards: the fangs are but very little narrower at their ends, which are pretty broad and often bifurcated. There are two cavities in each fang, one towards each edge leading to the general cavity in the body of the tooth. These two cavities are formed by the meeting of the sides of the fang in the middle, thereby dividing the broad and flat cavity into two ;f and all along the outside of these (and all the other flat fangs) there is a corresponding longitudinal groove. These fangs at their middle are generally bent a little backwards.J The enamel covers the bodies of these teeth pretty equally all round. The first grinder is somewhat larger and stronger than the second; it is turned a little more inwards than the adjacent bicuspides, but not so much as the second grinder. Both of them have generally shorter fangs than the bicuspides. There is a greater difference between these grinders in the upper and lower jaw than between any of the other teeth. In the upper

*P1. II. f. l,2,dd. t PI. III. f. 8, where four dark spots are observed. X ^> H* *• 4* 32 HUNTER ON THE TEETH. jaw they are rather rhomboidal than square in their body, with one sharp angle turned forwards and outwards, the other backwards and inwards; besides, they have three fangs, which diverge, and terminate each in a point: these are almost round, and have but one cavity. Two of them are placed near each other perpendicularly over the outside of the tooth; and the other, which generally is the largest, stands at a greater distance on the inside of the tooth, slanting inwards. In this jaw these two grinders are inclined outwards, and a little forwards; they project a little over the corresponding teeth of the lower jaw, and are placed further back in the mouth, so that each is partly opposed to two of the lower jaw. The second in the upper jaw is smaller than the others; and the first and second are placed directly under the maxillary sinus. I once saw the second grinder naturally wanting on one side of the lower jaw. The third grinder is commonly called dens sapientias: it is a little shorter and smaller than the others, and inclined a little more inwards and forwards. Its body is nearly of the same figure, but rather rounder, and its fangs are generally not so regular and distinct, for they often appear squeezed together; and sometimes there is only one fang, which makes the tooth conical: it is much smaller than the rest of the grinders. In the upper jaw this tooth has more variety than in the lower, and is even smaller than the corresponding tooth of the lower, and consequently stands directly opposed to it: but for this circumstance the grinders would reach farther back in the upper jaw than in the lower, which is not commonly the case In the upper jaw this third grinder is turned but a very little outwards, is frequently inclined somewhat backwards, and projects over that of the under jaw. It oftener becomes loose than any of the other teeth. J It is placed under the posterior part of the maxillary sinus, where the parts which compose the sinus are thicker than in the middle. I he variations as to the natural number of the teeth depend commonly upon the dentes sapientas.

CT,3n"ii fTi!he w!801'68 t0 the first Srinder' the teeth become giadually thicker at the extremity of their bodies, and smaller from the first grinder to the dens sapiential. From the cuspidatus to the dens sapientue. the fangs become much shorter: the incisores are nearly of the same length with the bicuspides. From the firs

andlums G ^ ^"^ ^ tGGth Stand le"S out *°» the soC£

waTSs6 atthe a^o^r? ^^^ZTT"^ * "f* °Ut" grinder, they are inclined graduVmWwaST' tV^ IP the upper jaw project over those of the under eS1Sinli? t ^ * part, which is owing to the greater ohE P/ aIly at the fore upperjaw; for the circle of t£ Sft,^ tCeth. \th? jaws. This oblique situation, however becn\JJ *Te ln both from the incisores backwards to the last grinder whi& ^ ksS' gradually project less in the same proton Whlchmakes them THE GRINDERS. 33 The teeth in the upper jaw are placed further back in the circle than the corresponding teeth of the lower ; this is owing to the two first incisores above being broader than the corresponding incisores below. All the teeth have only one fang, except the grinders, each of which has two in the lower jaw and three in the upper.* The fangs bear a proportion to the bodies of the teeth; and the reason is evident, for otherwise they would be easily broken, or pushed out of their sockets. The force commonly applied to them is oblique, not perpendicular; and they are not so firmly fixed in the upper jaw, that is, the alveolar process in that is not so strong, as in the under jaw : it is perhaps on this account that the grinders in that jaw have three fangs. This particular structure in the alveolar process of the upper jaw is perhaps to give more room for the antrum Highmorianum. On this supposition the fangs must be made accordingly, i. e. so that they shall not be pushed into that cavity: now, by their diverging they inclose, as it were, the bottom of the antrum, and do not push against its middle, which is the weakest part; and the points of three diverging fangs will make a greater resistance (or not be so easily pushed in) than if they were placed parallel. If there had been only two, as in the lower jaw, they must have been placed opposite to the thinnest part of the antrum ; and three points placed in any direction but a diverging one would have had here much the same effect as two; and as the force applied is endeavouring to depress the tooth, and push it inwards, the innermost fang diverges most, and is supported by the inner wall of the antrum. That all this weakness in the upper jaw is for the increase of the antrum is probable, because all the teeth in the upper jaw are a good deal similar to those in the lower, excepting those that are opposite to the maxillary sinus; and here they differ principally in the fangs, without any other apparent reason : and what confirms this is, that the dentes sapientise in both jaws are more alike than the other grinders,—for this reason, as I apprehend, because the dens sapientiae in the upper jaw does not interfere so much with the maxillary sinus. What makes it still more probable that the two first superior grinders have three fangs on account of the maxillary sinus is, that the two grinders on each side of the upper jaw, in the child, have three fangs, and we find them underneath the antrum; but those that succeed them have only one fang, as in the lower jaw; but by that time the antrum has passed further back, or rather the arch of the jaw has projected, or shot forwards, as it were, from under the antrum, so that the alveolar processes that were under it at one age are got before it in another. That the edge of every fang is turned towards the circumference * Those anatomists who allow the teeth to have more fangs have been led into a mistake ; I suppose, by often observing two canals in one fang, and thence concluding that such a fang was originally two, and that these were now grown together. 34 HUNTER ON THE TEETH. of the jaw, in order to counteract the acting power, we shall see when we consider the motion of the jaw and the use of the teeth.

Of the Articulation of the Teeth.

The fangs of the teeth are fixed in the gum and alveolar processes by that species of articulation called gomphosis, which in some measure resembles a nail driven into a piece of wood.* They are not, however, firmly united with the processes, for every tooth has some degree of motion ; and in heads which have been boiled or macerated in water, so as to destroy the periosteum and adhesion of the teeth, we find the teeth so loosely connected with their sockets that all of them are ready to drop out, except the grinders, which remain, as it were, hooked from the number and shape of their fangs.

The alveolar processes are covered by a red vascular substance, called the gums, which has as many perforations as there are teeth, and the neck of a tooth is covered by and fixed to this gum. Hence there are fleshy partitions between the teeth, passinf between the external and internal gum, and, as it were, uniting them : these partitions are higher than the other parts of he gum, and form an arch between every two adjacent'teeth. The thickness of th?t Lal° ^h SZ which.Pr°J-ts beyond the J^^Ldlr^ so that when the gum is corroded by disease, by boiling or o?her wise, the teeth appear longer, or less sunk into tL jaw tL lum andetroth?ty fA m & healthful State bolh to the alveolar prof™ the teeth %t' "* "I™6 b°rder is na,urj% ]°™ "l around

any great degree of Snsibil!ty? &To£h we Xn T V?" eating, and in picking our teeth yetwe d/L f i ?°™d lt ]" these occasion?- arJthmh in ' r V , not feel much Pa,n UP°" are no ?eeth the eui bl n ^ ^ °Id PeoPIe> where there pain. ' g mS bCar a Ver^ considerable pressure without

peoPle%ho have losf their tefth ha°veg n ^ Wh°le h^L ™ sound state, the gUms are'*LXirriStSV1^ When in * and therefore are not so liable to inflamma in Y bTg wounded> soon heal. " anamination as other parts, and The teeth being united to the iaw bv th* ■ have some degree of a yielding ^1^^ S™>

^eePI>II-f-4'f°rthet-h ^selves in their sockets." ACTION OF THE TEETH, ETC. 35 circumstance renders them more secure ; it breaks the jar of bony contact, and prevents fractures both of the sockets and of the teeth themselves.

Of the Action of the Teeth, arising from the Motion of the Lower Jaw.

The lower jaw may be said to be the only one that has any motion in mastication, for the upper jaw can only move with the other parts of the head. That the upper jaw and head should be raised in the common act of opening the mouth or chewing, would seem, at first sight, improbable; and from an attentive view of the mechanism of the joints and muscles of those parts, from experiment and observation, we find that they do not sensibly move. We shall only mention one experiment in proof of this, which seems conclusive. Let a man place himself near some fixed point, and look over it, to another distant and immoveable object, when he is eating. If his head should rise in the least degree he would see more of the distant object over the nearest fixed point, which in fact he does not. The nearer the fixed point is, and the more distant the object, the experiment will be more accurate and convincing. The result of the experiment will be the same if the nearest point has the same motion with the head, as when he looks from under the edge of a hat, or anything else put upon his head, at some distant fixed object. We may conclude, then, that the motion is entirely in the lower jaw; and, as we have already described both the articulation and the motion of the bone, we shall now explain the action of mastication, and at the same time consider the use of each class of teeth. With regard to the action of the teeth of both jaws in mastication, we may observe once for all that their action and reaction must be always equal, and that the teeth of the upper and lower jaws are complete and equal antagonists both in cutting and grinding. When the lower jaw is depressed, the condyles slide forwards on the eminences, and they return back again into the cavities when the jaw is completely raised. This simple action produces a grinding motion of the lower jaw, backwards on the upper, and is used when we divide anything with our fore teeth, or incisores. For this purpose the incisores are well formed: for as they are higher than the others, their edges must come in contact sooner; and as the upper project over the under, we find, in dividing any substance with them, that we first bring them opposite to one another, and as they pass through the part to be divided, the lower jaw is brought back, while the incisores of that jaw slide up behind those of the upper jaw, and of course pass by one another. In this way they complete the division, like a pair of scissors, and at the same time they sharpen one another. There are exceptions to this, for these teeth in some people meet equally, viz. in those people whose fore 36 HUNTER ON THE TEETH. teeth do not project further from the gum, or socket, than the back teeth; and such teeth are not so fit for dividing: and in some people the teeth of the lower jaw are so placed as to come before those of the upper jaw. This last situation is as favourable for cutting as when the overlapping of the teeth is the reverse, except for this circumstance, that the lower jaw must be longer, and therefore its action weaker. The other motion of the lower jaw, viz. when the lateral teeth are used, is somewhat different from the former. In opening the mouth one condyle slides a little forwards, and the other slides a little further back into its cavity; this throws the jaw a little to that side, just enough to bring the lower teeth directly under their corresponding teeth in the upper jaw : this is done either in dividing or holding of substances, and these are the teeth that are general!? used in the last-mentioned action. When the true grindinf motion is to be performed, a greater degree of this last motion tak?s place; that is, the condyle of the opposite side is brought further forwards, r?ifv nfT ? th,eusame side is d^wn further back into the cavity of the temporal bone, and the jaw is a little depressed. This rL°i Yf ^Pf at°ry f°r the effect to bc Produced, for the moving

The lateral teeth in both jaws are adapted to this oblique motion

mo e'i TV*167/1"6 ,Ur?ed a Htt,e inwards' that th^mTaei mo e in the direction of their axis; and here the alveolar process is s rongest upon the outside, being there sunoortpH h 1? •/

the same reason; and the longest fanr, if tu0 j outwards, for inside, where the socket isis^t^eSjf^th8^^8 " Up°n the tween the antrum and nosl * Hen^ thaVthe e^ oTthe l" bC" upler -^—edges worn down first, t^ ££ !nT ^ C0^riS°nS ^

s^^ »" -em to be a temporal bone is not yet formed7'JcTil ^ 6minenCe °f the the condyle ; therefore th? cenSe oW lty V0t larSer than condyle. In old people whVhnetrtT" 1" l^ mUSt be in the tion appears to be in the condyles and Jh? **? the Centre of mo" be only depression and elevation The' motlon°f >eir jaw to sufficiently to bring the condyle forwards^th? deprGSS the JaW in them the mouth is sufficiently opened ?i eLm,nence, because natural position. J p a wllen the jaw is in its Hence it is that in old people the j»nr«„ r *L meet in ,he fore part of .he"mou*,^ t^t^t fe*^ FORMATION OF THE ALVEOLAR PROCESSES. 37 part so well as at the side of the jaw; and, instead of the grinding motion, which would be useless where there are no grinders, they bruise their food rather by a simple motion of the jaw upwards and downwards. It is from the want of teeth in both these ages that the face is shorter in proportion to its breadth. In an old person, after the teeth are gone the face is shorter while the mouth is shut by almost the whole lengths of the teeth in both jaws; that is, about an inch * and a half. From the want of teeth, too, at both those ages, the cavity of the mouth is then smaller, and the tongue seems too large and unmanageable, more especially in old people. In these last we observe also that the chin projects forwards in proportion as the mouth is shut, because the basis of the lower jaw (which is all that now remains,) describes a wider circle than the alveolar process in younger people. The jaws do not project so much forwards in a child°as in an adult; hence the face is flatter, especially at the lower part. In proportion as the last grinders are produced, the sides of the curve formed by the jaws become longer, and push forward the fore part, none of the additional part passing backwards. The fore part also continues nearly of the same size, so that the whole jaw is longer in proportion to its breadth, and projects further forwards.

Of the Formation of the Alveolar Processes.

Having considered the alveolar processes in their adult, or perfect state, we shall next examine and trace them from their beginning. We may observe the beginning of the alveolar process at a very early period. In a foetus of three or four months it is only a longitudinal groove, deeper and narrower forwards, and becoming gradually more shallow and wider backwards: instead of bony partitions, dividing that groove into a number of sockets, there are only slight ridges across the bottom and sides, with intermediate depressions, which mark the situation of the future alveoli. In the lower jaw the vessels and nerves run along the bottom of this alveolar cavity in a slight groove, which afterwards becomes a complete and distinct bony canal. The alveolar process grows with the teeth, and for some time keeps the start of them. The ridges which are to make the partitions shoot from the sides across the canal, at the mouth of the cell, forming hollow arches : this change happens first at the anterior part of the jaws. As each cell becomes deeper, its mouth also grows narrower, and at length is almost, but not quite, closed over the contained tooth. . The disposition for contracting the mouth of the cell is chiefly in the outer plate of the bone, which occasions the contracted orifices of the cells to be nearer the inner edge of the jaw. The reason, 5* 38 HUNTER ON THE TEETH. perhaps, why the bone shoots over, and almost covers the tooth, is that the gum may be firmly supported before the teeth have come through. The alveoli which belong to the adult grinders are formed in another manner; in the lower jaw they would seem to be the remains of the root of the coronoid process, for the cells are formed . for those teeth in the root of that process; and in proportion as the body of the bone, and the cells already formed, push forwards from under that process, the succeeding cells and their teeth are formed, and pushed forward in the same manner. In the upper jaw there are cells formed in the tubercles for the young grinders, which at first are very shallow, and become deeper and deeper as the teeth grow ; and they grow somewhat faster, so as almost to inclose the whole tooth before it is ready to pu«h its way through that inclosure and gum.* There is a succession of these till the whole three grinders are formed.

Of the Formation of the Teeth in the Fcetus.

The depressions or first rudiments of the alveoli observable in a foetus of three or four months, are filled with four or five little pulpy substances which are not very distinct at this age. About the fifth month both the processes themselves and the pulpy substances A^T\w°Ve dfincVhe a"teri0r of which are the most compete About this age, too, the ossifications begin on the edge of the first incisores. The cuspidati are not in the'same circular line with the rest, but somewhat on the outside, making a projection here at this age there not being sufficient room for them About the sixth or seventh month the edges or tips of all these five substances have begun to ossify, and thl first of them is a little advanced; and besides these, the pulp of the sixth I h V to be formed : it is situated in the" tKcle of the upper twlnd"

-~^ffSu^s ^JiTon>and ibout the cut or pass through the gums first ,~ ,, incisores begin to Before this time the ossifiSn^"a,^-,?I,yf. in the *™e? jaw. makes the first in the adult, have begun finder, or that which The cuspidati and molares of the fo>fn* „ the mcisores; they generally all aDnP! "ot formed so fast as / appear nearly about the same Pi- IV. f. i. CAUSE OF PAIN IN DENTITION. 39 time, viz. about the twentieth or twenty-fourth month; however, the first grinder is often more advanced within the socket than the cuspidatus, and most commonly appears before it. These twenty are the only teeth that are of use to the child from the seventh, eighth, or ninth month, till the twelfth or fourteenth year. These are called the temporary, or milk teeth, because they are all shed between the years of seven and fourteen, and are supplied by others.

Of the Cause of Pain in Dentition.

These twenty teeth in cutting the gum give pain, and produce many other symptoms which often prove fatal to children in dentition. It has been generally supposed that these symptoms arise from the tooth's pressing upon the inside of the gum, and working its way mechanically ; but the following observations seem to be nearer the truth. The teeth, when they begin to press against the gum, irritate it, and commonly give pain. The gums are then affected with heat, swelling, redness, and the other.symptoms of inflammation. The gum is not cut through by simple or mechanical pressure, but the irritation and consequent inflammation produces a thinning or wasting of the gum at this part; for it often happens, that when an extraneous or a dead substance is contained in the body, it produces a destruction of the part between it and that part of the skin which is nearest it, and seldom of the other parts, excepting those between it and the surface of a cavity opening externally, and that by no means so frequently; and in those cases there is an absorption of the solids, or of the part destroyed, not a melting down or solution of them into pus. The teeth are to be looked upon as extraneous bodies with respect to the gum, and as such they irritate the inside of that part in the same manner as the pus of an abscess, an exfoliation of a bone, or any other extraneous body, and therefore produce the same symptoms, excepting only the formation of matter. If, therefore, these symptoms attend the cutting of the teeth, there can be no doubt of the propriety of opening the way for them; nor is it ever, as far as I have observed, attended with any dangerous consequence.*

* [There can indeed be no doubt that the emancipation of the rising tooth is occasioned by absorption of the gum, but it is also probable that this absorption is increased, if not wholly produced, by the pressure of its edge on the horizontal surface of the tooih. It appears probable, therefore, that when, in consequence of the rapid elongation of the root, the crown of the tooth rises faster than this process for the removal of the containing parts goes on, an undue pressure takes place on the inside of the gum, and local inflammation, accompanied by much constitutional disturbance, is the result. The mere existence of the tooth in contact with the gum " as an extraneous body," would not account for all this disturbance, for after the gums are lanced the tooth is still in contact with the soft parts; but because the pressure is thus taken off, the irritation immediately subsides.] 40 HUNTER ON THE TEETH. Of the Formation and Progress of the Adult Teeth.

Having now considered the first formation and the progress of the temporary teeth, we shall next describe the formation of those teeth which are to serve through life. In this inquiry, to avoid confusion, I shall confine the description to the teeth in the lower jaw, for the only difference between those in the two jaws is in the time of their appearance, and generally it is later in the upper jaw. Their formation and appearance proceed not regularly from the first incisor backwards to the dens sapientiae, but begin at two points on each side of both jaws, viz. at the first incisor and at the first molaris. The teeth between these two points make a quicker progress than those behind. The pulps of the first adult incisor and of the first adult molaris begin to appear in a foetus of seven or eight months ; and five or six months after birth the ossification begins in them. Soon after birth the pulps of the second incisor and cuspidatus begin to be formed, and about eight or nine months afterwards they begin to ossify. About the fifth or sixth year the first bicuspis appears ; about the sixth or seventh, the second bicuspis and the second molaris; and about the twelfth, the third molaris, or dens sapiential The first five may be called the permanent teeth : they differ from the temporary in having larger fangs. The permanent incisores and cuspidati are much thicker and broader; and the molares are succeeded by bicuspides, which are smaller, and have but one fang. All these permanent or succeeding teeth are formed in distinct alveoli of their own, so that they do not fill up the old sockets of the temporary teeth, but have their new alveoli formed as the old ones decay.* The first incisor is placed on the inside of the root of the corresponding temporary tooth, and deeper in the jaw. The second incisor and the cuspidatus begin to be formed on the inside, and Th«pW.hat ^n^ temP°raiT ^cond incisor and cuspidatus lZ tl\T^\ SltUaiGd mUCh,in thG Same manner withPrespect 1^^^™^^ tkey arG P,aCGd S°mJhat

tha?t^hrPiS iS P,aC6d Unde5' and somew^t further back than the fiist temporary grinder, or fourth tooth of the child.

tenTpta^glder81518 " ^ immediately under the second The second molaris is situated in the lencrth^n;™ ♦ u i • .. upper jaw, and directly under the coronoid gnf g.tulf rc,le ln the The third molaris, or dens sapienZ hi P °Cef m the lowerunder the coronoid process Sapi6ntia3' beSms to form immediately The first adult molaris comes to nprf^;~ j *>«, the Uve,f,h year of age, the slZ^Cn^^Z

' PI. IV. f. 1,2,3. FORMATION AND PROGRESS OF THE ADULT TEETH. 41 the third, or dens sapientise, from the twentieth to the thirtieth; so that the incisores and cuspidati require about six or seven years from their first appearance to come to perfection, the bicuspides about seven or eight, and the molares about twelve. It sometimes happens that a third set of teeth appears in very old people ; when this does happen it is in a very irregular manner, sometimes only one, at other times more, and now and then a complete set comes in both jaws. I never saw an instance of this kind but once, and there two fore teeth shot up in the lower jaw. I should suppose that a new alveolar process must be also formed in such cases, in the same manner as in the production of the first and second sets of teeth. From what I can learn, the age at which this happens is generally about seventy. From this circumstance, and another that sometimes happens to women at this age, it would appear that there is some effort in nature to renew the body at that period. When this set of teeth which happens so late in life is not complete, especially where they come in one jaw and not in the other, they are rather hurtful than useful, for in that case we are obliged to pull them out, as they only wound the opposite gum.*

* [This account of the manner in which the permanent teeth are formed is exceedingly imperfect. The observations of Dr. Blake, (recorded first in his inaugural thesis, and afterwards published in English in an enlarged form,) first made known the process by which this extraordinary formation is produced. Subsequent investigations have confirmed the general views given by Blake, and I make no apology for offering the following account of the process, which is substantially the°same as I have already given in another work. The formation of the permanent teeth, although essentially proceeding upon the same general principle, and produced by means of similar structures as those by which the temporary ones are formed, differs in some very remarkable points from that process. The rudiments of the permanent teeth, instead of being original and independent, like those of the temporary, are, in fact, derived from them and remain for a considerable time attached to and intimately connected with them. (See PI. V. f. 9, 10, 11, 12.) At an early period in the formation of the temporary teeth, by a process which reminds us of the gemmiparous reproduction in the lower grades, both of animal and vegetable life, the investing sac, or capsule, gives off a small process, a bud containing a portion of the essential rudiments, namely, the pulp, covered by its proper membrane. This constitutes the rudiment of the permanent tooth. It commences in a small thickening on one side of the parent sac, which gradually becomes more and more circumscribed, and at length assumes a distinct lorm, though still connected with it by a peduncle, which is nothing more than a process of the investing sac. For a time the new rudiment is contained within the same alveolus with Its parent, which is excavated by the absorbents for its receDtion bv a process almost unparalleled in the phenomena of physiology. It is not nroduced by the pressure of the new rudiment, as has been erroneously believed but commences in the cancelli of the bone immediately within its smooth surface thus constituting what may be termed a process of anticipation, lhe new cell after bein«r sufficiently excavated, and as the rudiment continues to increase, is gradually separated from the former one, by being more and more deeDlv excavated in the substance of the bone, and also by the deposition of a honv partition between them; and at length the new rudiment is shut up in its popVsocket, though still connected with the temporary tooth by the cord or 42 HUNTER ON THE TEETH. The Manner in which a Tooth is formed.

The body of the tooth is formed first, afterwards the enamel and fangs are added to it. All the teeth are produced from a kind of pulpy substance, which is pretty firm in its texture, transparent, excepting at the surface, where it adheres to the jaw, and has at first the shape of the bodies of the teeth which are to be formed from it.* These pulpy substances are very vascular: they adhere only at one part to the jaw, viz. at the bottom of the cavity which is to form the socket, and at that place their vessels enter, so that they are prominent and somewhat loose in the bony cavity which lodges them. They grow nearly as large as the body of the tooth before the ossification begins, and increase a little for some time after the ossification has begun. They are surrounded by a membrane, which is not connected with them, excepting at their root or surface of adhesion. This membrane adheres by its outer surface all around the bony cavity in the jaw, and also to the gum where it covers the alveoli. When the pulp is very young, as in the foetus of six or seven months, this membrane itself is pretty thick and gelatinous.f We can examine it best in a new-born child, and we find it made up of two lamellae, an external and internal: the external is soft and spongy, without any vessels; the other is much firmer and extremely vascular, its vessels coming from those that are going to

SSfPth !h?iil TkeS 1 ldnd °f caPsu,e for the pulplnd body of the tooth While the tooth is within the gum there is always a mucilaginous fluid like the synovia in the joints, between this membrane and the pulp of the tooth.

flfpThXthe t0°th^T thG gUm' this membrane likewise is perforated, after which it begins to waste, and is entirely gone by the

^^i^\lx$jrAh*which has in the mean time b- ■* tnJhehn!,tUatT °Z e3Ch Permanent ^diment when its corresponding temporary S later Tnd" rLlXZ^f ^f" ^ gUm' JS be"eath ""da littleTehS stemen6;; t"w*it' SdnTSn^C^tih^ *""* ***««*<*

of the new process of pulp in its first nrodno,in uT,d \ai° the comP°sition and modified in their StructureasultiCel vSfofm ^ '* ^i™ S° ^^ This is much more probable than to suppWthJ » * ^ de"tal brancheS< sels is given off from the maxillary branchestoY?W*et of nerve* ™* vesthrough an intervening layer of bone of an indefinite \l- i pulpS at a distance> new tooth. 'naennite thickness, to supply every Wu6- "uT'therefore' find the ^w rudiment in a stite no i in which the parent tooth was oriainally placed a„i ■ ? Hy analogous to that surrounding parts; the sac above, attached to thl S1milar relations to the (covered with its proper membrane,) connected by ^TsAT^^^ ri. r. i. «, o, b, |P1. V. f 1 o Jaws,l OSSIFICATION OF A TOOTH, ETC. 43 time the tooth is fully formed, for the lower part of the membrane continues to adhere to the neck of the tooth, which has now risen as high as the edge of the gum.*

Of the Ossification of a Tooth upon the Pulp.

The beginning of the ossification upon the pulp is by one point, or more, according to the kind of tooth. In the incisores it is generally by three points, the middle one being the highest, and the first that begins to ossify. The cuspidatus begins by one point only; the bicuspis by two, one externa], which is the first and the highest, and the other internal. The molares, either in a child or an adult, begin by four or five ossifications, one on each point, the external always the first. Where the teeth begin to ossify at one point only, that ossification gradually advances till the tooth is entirely completed; but if there is more than one point of ossification, each ossification increases till their bases come in contact with one another, and there all unite into one, after which they advance in growth as one ossification. The ossifications in their progress become thicker and thicker where they first began, but increase faster on the edges of the teeth; so as thence to become more and more hollow, and the cavity becomes deeper.f As the ossification advances, it gradually surrounds the pulp till the whole is covered by bone, excepting the under surface ; and while the ossifications advance, that part of the pulp which is covered by bone is always more vascular than the part which is not yet covered.J The adhesion of the pulp to the new-formed tooth or bone is very slight, for it can always be separated from it without any apparent violence, nor are there any vessels going from the one to the other; the place, however, where it is most strongly attached is round the

* [The statement that the bone of a tooth is produced from the pulp is erroneous. This substance constitutes only the mould upon which the ossification is formed, between which and the pulp is placed a membrane of extreme tenuity, which I have termed the proper membrane of the pulp. It is slightly attached to the surface of the pulp, which it completely covers, and it is from the outer surface of this membrane that the bone is secreted. As the pulp recedes on the deposit of the successive laminae of bone, the ossific membrane continues to cover it, and ultimately forms the well-known membrane lining the internal cavity of the perfect tooth. The double investing membrane or sac which surrounds the whole rudiment as far as the neck of the tooth, and no further, has been proved, by repeated injections, to be vascular throughout, though Hunter states the internal, and Blake the external layer to be exclusively so. It is from the inner surface of this capsule that the enamel is secreted, as will be more particularly noticed hereafter. As soon as the enamel is secreted the capsule becomes absorbed, beginning at the edge or horizontal surface of the tooth, where the enamel is first deposited. It is, therefore, not perforated by the rising of the tooth, as inferred in the text, but absorbed as soon as it has performed its single function.] f PI. V. f. 14, a, b, c, d, two rows of incisors sawed down the middle, the highest of the child, the other of the adult: e,f, g, two rows of grinders showing the same circumstances. X PI. V. f. &, 6. 44 HUNTER ON THE TEETH. edge of the bony part, which is the last part formed. When the bone has covered all the pulp, it begins to contract a little and becomes somewhat rounded, making that part of the tooth which is called the neck; and from this place the fangs begin.* When the fangs form, they push up the bodies of the teeth through the sockets, which waste, and afterwards through the gum, which also wastes, as has been explained upon the cutting of the teeth ; for before this time the rising of the teeth is scarce observable, as the pulp was at first nearly of the size of the body of the tooth itself, and wasted nearly in proportion to the increase of the whole ossification. The pulp has originally no process answering to the fang ;f but as the cavity of the body of the tooth is filled up by the ossification, the pulp is lengthened into a fang. The fang grows in length and rises higher and higher into the socket till the whole body of the tooth is pushed out. The socket at the same time contracts at its bottom, and grasping the neck or beginning fang, adheres to it and rises with it, which contraction is continued through the whole length of the socket as the fang rises; or the socket which contained the body of the tooth, being too large for the fang, is wasted or absorbed into the constitution, and a new alveolar portion is raised with the fang; whence in reality the fang does not sink or descend into the jaw. Both in the body and in the fang of a growing tooth, the extreme edge of the ossification is so thin, transparent, and flexible, that it would appear rather to be horny than bony, very much like the mouth or edge of the shell of a snail when it is growing; and indeed it would seem to grow much in the same manner,J and the ossified part of a tooth would seem to have much the same connexion with the pulp as a snail has with its shell. As the tooth grows, its cavity becomes gradually smaller, especially towards the point of the fang. In tracing the formation of the fang of a tooth we hitherto have been supposing it to be single, but where there are two or more it is somewhat different and more complicated. When the body of a molaris is formed, there is but one general cavity in the body of the tooth, from the brim of which the ossification is to shoot, so as to form two or three fangs.fc If two only, then the opposite parts of the brim of the cavity of the tooth shoot across where the pulp adheres to the jaw, meet in the middle, and thereby divide the mouth of the cavity into two openings ;|| and from the edges of these two openings the two fangs grow.l We often find that a distinct ossification begins in the middle of the general cavity upon the root of the pulped two proceLa coming from the opposite edges of the bony sheS iZ it which answers the same purpose. y J in ll' wnicn When there are three francs we wp tk™,. * PI. V f 13 14 15 Processes coming from % Pi'. V. f. 13,' 14,' 15.' J PL V. f. 1, 4, 5, 6. FORMATION OF THE ENAMEL. 45 so many points of the brim of the cavity, which meet in the centre and divide the whole into three openings ;* and from these are formed the three fangs.f We often find the fangs forked at their points, especially in the bicuspides. In this case the sides of the fang as it grows come close together in the middle, making a longitudinal groove on the outside; and this union of the opposite sides divides the mouth of the growing fang into two orifices, from which the two points are formed. By the observations which I have made in unravelling the texture of the teeth when softened by an acid, and from observing the disposition of the red parts in the tooth of growing animals interruptedly fed with madder, I find that the bony part of a tooth is formed of lamellse placed one within another. The outer lamella is the first formed and is the shortest; the more internal lamella? lengthen gradually towards the fang, by which means, in proportion as the tooth grows longer, its cavity grows smaller, and its sides grow thicker.J How the earthy and animal substance of the tooth is deposited on the surface of the pulp is not perhaps to be explained.^

Of the Formation of the Enamel.

In speaking of the enamel we postponed treating of its formation till it could be more clearly understood; and now we shall previously describe some parts which we apprehend to be subservient to its formation, much in the same manner as the pulp is to the body of the tooth. From its situation and from the manner in which the teeth grow, one would imagine that the enamel is first formed ; but the bony part begins first, and very soon after the enamel is formed,upon it. There is another pulpy substance opposite to that which we have described: it adheres to the inside of the capsule, where the gum is joined to it, and its opposite surface lies in contact with the basis of the above-described pulp, and afterwards with the new-formed basis of the tooth. Whatever eminences or cavities the one has, the other has the same, but reversed, so that they are moulded exactly to each other. In the incisores it lies in contact, not with the sharper cutting edge of the pulp or tooth, but against the hollowed inside of the tooth; and in the molares it is placed directly against their base, like a tooth of the opposite jaw. It is thinner than the other pulp, and decreases in proportion as the teeth advance. It does not seem to be very vascular. The best time for examining it is in a foetus of seven or eight months old. In the graminivorous animal, such as the horse, cow, &c, whose teeth have the enamel intermixed with the bony part,|| and whose teeth, when forming, have as many interstices as there are con-

* * PI. V. f. 13, F, G. f PI. V. f. 13, H, I, K. % PI. V. f. 7, 8. § This is explained in the note to the preceding section. || PI. III. f. 20, 21. 46 HUNTER ON THE TEETH. tinuations of the enamel, we find processes from the pulp pawing down into those interstices as far as the pulp which the tooth is formed from, and there coming into contact with it. After the points of the first-described pulp have begun to ossify, a thin covering of enamel is spread over them, which increases m thickness till some time before the tooth begins to cut the gum. The enamel appears to be secreted from the pulp above described, and perhaps from the capsule which incloses the body of the tooth. That it is from the pulp and capsule seems evident in the horse, ass, ox, sheep, &c, therefore we have little reason to doubt of it in the human species. It is a calcareous earth, probably dissolved in the juices of our body, and thrown out from these parts, which act here as a gland. After it is secreted, the earth is attracted by the bony part of the tooth which is already formed, and upon that surface it crystallizes. The operation is similar to the formation of the shell of the egg, the stone in the kidneys and bladder, and the gall stone. This account for the striated crystallized appearance which the enamel has when broken, and also for the direction of these stria?.* The enamel is thicker at the points and basis than at the neck of the teeth, which may be easily accounted for from its manner of formation ; for if we suppose it to be always secreting, and laid equally over the whole surface, as the tooth grows, the first formed will be the thickest; and the neck of the tooth, which is the lastformed part inclosed in this capsule, must have the thinnest coat; and the fang, where the periosteum adheres, and leaves no vacant space, will have none of the enamel. At its first formation it is not very hard ; for by exposing a very young tooth to the air the enamel cracks and looks rough; but by the time that the teeth cut the gum, the enamel seems to be as hard as ever it is afterwards; so that the air seems to have no effect in hardening it.f

* The author has made many experiments on the formation of different calculi, and finds they are formed by crystallization, which were communicated to his brother, and taught by him to his pupils in 1761, and which he proposes to give to the public as soon as his time will permit. f [According to the most accurate observations which I have been able to make, and they are confirmed by those of others, the substance which Hunter terms "another pulpy substance," adhering to the inside of the capsule, is nothing more than a thickened and turgid state of the inner layer of the capsule itself, surcharged with blood and probably also with the earthy matter which it tooth Thi0?h°Sl' c.onstltutlnS the future enamel-covering of the crown of the ooth. This thickening appears to be somewhat analogous to that extraordinary tumescence which is observable in the mantle of certafI species of snaiI as 2 own Hehx Fomatia immediately before the calcareousi win* P . ' a out from every part of its surface. calcareous winter operculum is poured The enamel when just deposited is not much more «mi,l (K„n ,u- i It soon sets, but is at first but little coherent, bein^easilv ml ? x*C\ T ally, however, assumes its crystalline form, become?^ Pulver,sed 5 li 8Tadu" tremely hard.] ' Decoines semitransparent, and ex- MANNER OF SHEDDING THE TEETH. 47 Of the Manner of Shedding the Teeth.

An opinion has commonly prevailed that the first set of teeth is pushed out by the second; this, however, is very far from being the case ; and were it so, it would be attended with a very obvious inconvenience; for, were a tooth pushed out by one underneath, that tooth must rise in proportion to the growth of the succeeding one, and stand in the same proportion above the rest. But this circumstance never happens, neither can it, for the succeeding teeth are formed in new and distinct sockets, and generally the incisores and the cuspidati of the second set are situated on the inside of the corresponding teeth of the first set ;* and we find that in proportion to the growth of the succeeding teeth, the fangs of the first set decay, till the whole of the fang is so far destroyed that nothing remains but the neck, or that part of the fang to which the gum adheres,f and then the least force pushes the tooth out. It would he very natural to suppose that this was owing to a constant pressure from the rising teeth against the fangs or sockets of the first set, but it is not so ; for the new alveoli rise with the new teeth, and the old alveoli decay in proportion as the fangs of the old teeth decay, and when the first set falls out, the succeeding teeth are so far from having destroyed, by their pressure, the parts against which they might be supposed to push, that they are still inclosed and covered by a complete bony socket. From this we see that the change is not produced by a mechanical pressure, but it is a particular process in the animal economy. I have seen two or three jaws where the second temporary grinders were shedding in the common way, without any tooth underneath; and in one jaw, where both the grinders were shedding, I met with the same circumstance. A remarkable instance of this sort occurred to me in a lady who desired me to look at a loose tooth, which I found was the last temporary tooth not yet shed. I desired that it might be drawn out, and told her it was of no use and could not by any art be fixed, as it was one of the teeth that is naturally shed, and that another might come in its place: however, she was disappointed. These cases prove evidently, that in shedding, the first teeth are not pushed out by the second set, but that they grow loose and fall out of their own accord. That the succeeding teeth have some influence on the shedding of the temporary set is proved by those very cases; since in one of the first mentioned the person was above twenty years of age, and in the other the lady was thirty; and it is reasonable to believe, that the shedding of these teeth was so late in those instances from the want of influence, whatever it is, of the new teeth. When the incisores and cuspidati of the new set are a little advanced, but long before they appear * PI. VI. f. 2, 3. . f PI. V. f. 16, 17, and 18, which show the gradual decay in the single ana double teeth, and also in one grinder of a horse. 48 HUNTER ON THE TEETH. through their bony sockets, there are small holes leading to them on the inside, or behind the temporary sockets and teeth; and these holes grow larger and larger, till at last the body of the tooth passes quite through them.*

Of the Growth of the Two Jaws.

As a knowledge of the manner in which the two jaws grow will lead to the better understanding of the shedding of the teeth, and as the jaws seem to differ, in their manner of growing, from other bones, and also vary according to age, it will be here proper to give some account of their growth. In a foetus three or four months old, we have described the marks of four or five teeth, which occupy the whole length of the upper jaw, and all that part of the lower which lies before the coronoid process, for the fifth tooth is somewhat under that process. These five marks become larger, and the jaw-bones of course increase in all directions, but more considerably backwards; for in a foetus of seven or eight months the marks of six teeth in each side of both jaws are to be observed, and the sixth seems to be in the place where the fifth was ; so that in these last four months the jaw has grown in all directions in proportion to the increased size of the teeth, and besides has lengthened itself at its posterior end as much as the whole breadth of the socket of that sixth tooth. The jaw still increases in all points till twelve months after birth, when the bodies of all the six teeth are pretty well formed; but it never after increases in length between the symphisis and the sixth tooth; and from this time, too, the alveolar process, which makes the anterior part of the arches of both jaws, never becomes a section of a larger circle, whence the lower part of a child's face is Hatter, or not so projecting forwards as in the adult. After this time the jaws lengthen only at their posterior ends; so hat the sixth tooth which was under the coronoid process in the ower jaw, and in the tubercles of the upper jaw of the foetus, is at ast, viz. in the eighth or ninth year,placed before these parts; and then the seventh tooth appears in the place which the sixth occupied, twpmhT'f tofthefkcoronoid Process and tubercle; and about the sevfnth w/°U[ Gn,th yAeaVhe eiShth tooth is sit"ated where the ooth 11 5 w- Au the a§e of ei§hteen or twenty, the eighth tooth is found before the coronoid process in the lower iaw and under, or somewhat before the tubercle in L, jaw and tubercle is no more than a succession if 1 t, ?PGr ujaW' W,hlC£ they are completely formed SUCCeSS1°n of sock^ for the teeth till

* [In the last paragraph of the section is an aAA„; j • misunderstanding of the relation of the permanent tit. ,nstance of the total their formation. The holes which have been desorih a • temPorar}' teeth during foramina through which the communicatino- cordI ff, '" a/ormer note, as the rudiment to the neck of the temporary tooth are hlP , the permanent commencement of the openings throuah which th'^erroneo"sly stated to be the subsequent progress. See PI. V. 9, 10, Tl,12.] ' Permanent teeth pass in their REASON FOR SHEDDING THE TEETH. 49 In a young child the cavity in the temporal bone for the articulation of the jaw is nearly in a line with the gums of the upper jaw ; and for this reason the condyle of the lower jaw is nearly in the same line; but afterwards, by the addition of the alveolar process and teeth, the line of the gums in the upper jaw descends considerably below the articular cavity; and for that reason the condyloid process is then lengthened in the same proportion. In old people who have lost all their teeth, the articulation comes again into the same line with the gums of the upper jaw ; but in the lower jaw, the condyles cannot be diminished again for accommodating it to the upper, so that it necessarily projects beyond the gums of the upper jaw at the fore part. When the mouth is shut, the projection of the jaw at the chin fits the two jaws to each other at that place where the grinders were situated, and where the strength of mastication lies; for if the chin was not further from the centre of motion than the gums of the upper jaw, at the fore part, the jaws, in such people as have lost all their teeth, would meet in a point at the fore part, like a pair of pincers, and be at a considerable distance behind.

The Reason for the Shedding of the Teeth.

As the shedding of the teeth is a very singular process in the animal economy, many reasons have been assigned for it; but these reasons have not carried along with them that conviction which is desired. Authors have not fully considered the appear^ ances; which naturally explain themselves; nor have they considered the advantages necessarily arising from the size and construction of only such a number as the first set; nor have they considered fully the disadvantages that such size and construction would have, if continued when it is necessary to have a great number, which is the case with the adult. We shall consider these advantages in a child where the shedding-teeth are all completely formed, which will be setting them in the clearest point of light; and also the disadvantages that would occur if in the adult these were not changed for another set somewhat different. If the child had been so contrived as not to have required teeth till the time of the second set appearing, there would have been no occasion for a new set; but the jaw-bones being considerably smaller in children than in adults, and it being necessary that they should have two grinders, there is not room for incisores and cuspidati of sufficient size to serve through life; and the first-formed grinders have necessarily two small fangs, and the jaw increasing at the back part only, these two grinders would have been protruded too far forwards, and at two great a distance from the centre of motion. This variation in the size of the teeth is likewise a reason why the second set are not formed in the sockets of the first, and why the old sockets are destroyed. 6* 50 HUNTER ON THE TEETH.

m. • ♦ «* «-ith regard to the shedding of the teeth, These circumstances^ th regard lo s broader and

ve the resistance would be greater to them than to ^e incisores 7 From the manner in which the teeth are shed, it is evident that drawing a temporary tooth for the easier protrusion of the one underneath, will be of no great service; for in general it falls out before the other can touch it. But it is often of much more service to pull out the neighbouring or adjacent temporary tooth for we must be convinced by what has been advanced with regard to the changes in size, that excepting the whole were to be shed at the same time, or the order of shedding, viz. from before backwards, were to be inverted, that the second set of incisores and cuspidati must be pinced in room till the grinders are also shed, and therefore we find it often of use to draw a temporary tooth that is placed further back; and it would, perhaps, be right upon the whole, always to draw at least the first grinder, and perhaps, some time after, the second grinder also.*

Of the Cavity filling up as the Teeth wear down.

A tooth very often wears down so low that its cavity would be exposed if no other alteration were produced in it. To prevent this, Nature has taken care that the bottom part of the cavity should be filled up by new matter in proportion as the surface of the teeth is worn down. This new matter may be easily known from the old, for when a tooth has been worn down almost to the neck, a spot may always be seen in the middle, which is more transparent, and at the same time of a darker colour (occasioned in some measure by the dark cavity under it), and generally softer

* [The practice here recommended, " always to draw at least the first grinder" of the temporary set, has been but too much followed by the interested or ignorant, who have readily shielded their malpractice under the authority of Hunter's name. The early extraction of any of the temporary teeth to make room for the permanent ones is rarely necessary, and it is on all accounts to be deprecated, unless the peculiar circumstances of ihe case imperatively call for it. But the removal of the large molar teeth of the child, in anticipation of a future deficiency of room, is so obviously uncalled for, and such a wanton interference with the usual process of nature, that we cannot but wonder at its being proposed as a general rule, even were there no positive evils to be apprehended from it: but this is not all; not only does the premature removal of the temporary molares endano-er the perfect formation of the bicuspides which succeed them, by the forcible laceration of the connecting cord before described, but, if it take place before the permanent teeth are ready to fall into their ultimate situation, the jaw will contract as the rh.ld grows, and the second set of teeth will be forced into an irregular position, from permanent want of room. These arguments hold good against the too early removal of any of the deciduous teeth.] CONTINUAL GROWTH OF THE TEETH. 51 than the other.*6 Any person may be convinced of the truth of these observations by taking two teeth of the same class, but of very different ages, one just completely formed, the other worn down almost to its neck. In the last he will observe the dark spot in the centre, and if as much is cut off from the complete tooth as has been worn off from the old one, the cavity of the young tooth will be found cut through ; and on examining the other, its cavity will be found filled up below that surface. Now this observation contradicts the idea of the hole leading into the cavity of the tooth being closed up ; and what is still a further proof of it, I have been able to inject vessels in the cavities of the teeth in very old people when the alveolar process has been gone, and the teeth very loose in the gum. Old people are often found to have very good sets of teeth, only pretty much worn down. The reason of this is, that such people never had any disorder in their teeth, or alveolar processes, sufficient to occasion the falling of one tooth. For if by accident one tooth is lost, the rest will necessarily fail in some degree, even though they are sound, and likely to remain so, had not this accident happened ; and this weakening cause is greater in proportion to the number that are lost. From this observation we see that the teeth support one another.f

Of the Continual Growth of the Teeth.

It has been asserted that the teeth are continully growing, and that the abrasion is sufficient to keep them always of the same length; but we find that they grow at once to their full length, and that they gradually wear down afterwards, and that there is not even the appearance of their continuing to grow. The teeth would probably project a little further out of the gum if they were not opposed by those in the opposite jaw; for in young people who had lost a tooth before the rest had come to their full length, I have seen the opposite tooth project a little beyond the rest before they were at all worn down. It may be further observed, that when a tooth is lost, the opposite one may project from the disposition of the alveolar process to rise higher, and fill up at the bottom of the sockets; and the want of that natural pressure seems to give that

* PI. III. f. 25, 26. . f [The filling up of the internal cavity of teeth in old people here alluded to, appears to be consequent upon the loss of substance from the surface. As the superstratum of bone becomes thinner by abrasion, the membrane lining the internal cavity, from which, as I have before shown, the bone of the tooth loas originally produced, now again resumes its ossific action, and produces a fresh layer of bony matter, which in some cases atlength fills the socket, and obliterates the membrane from which it has been secreted. This is particularly the case in sailors who have lived much upon hard biscuits, a circumstance which tends o-reatly to accelerate this abrasion of the surface, a process perfectly and obviously analoo-ous to that of the wearing cf the teeth in graminivorous animals.] 52 HUNTER ON THE TEETH.

a- •»• * <uM nrnrrsses which is best illustrated in those disposition to these processes, \\in^u . teeth which are formed deeper in their sockets than usual..As a proof that the teeth continue growing, it has been said that the Kace of a fallen tooth is almost filled up by the increased thickness of the two adjacent teeth, and the lengthening of that which is opposite. There is an evident fallacy in the case; either he observations have been made upon such jaws as above described, or the appearances have not been examined with sufficient accuracy; for when the space appears to have become narrow by the approximation of the two adjacent teeth, it is not owing to any increase of their breadth, but to their moving from that side where they are well supported to the other side, where they are not. * or this reason they get an inclined direction; and I observe it extends to the several adjacent teeth in a proportionally less degree, and affects those which are behind more than those which are before the vacant space. In the lower jaw the back teeth are not fixed perpendicularly, but all inclined forward, and the depression of the jaw increases this position; the action of the teeth, when thrown out of the perpendicular, has also a tendency to increase that oblique direction, as a pair of scissors, in cutting, pushes everything forward, or from the centre of motion; therefore this alteration, I think, is most commonly observable in the lower jaw. And that teeth are not actually always growing in breadth, must be obvious to every person who considers, that in many people, through life, the teeth stand so wide from each other that there are considerable spaces between them, which could not be the case if they were always growing in thickness. We might add, too, that according to the hypothesis the dens sapientias should grow to an enormous size backward, because there it has no check from pressure; and in people where the dens sapientias is wanting in one jaw, which is very common, it should grow to an uncommon length in the opposite jaw, for the same reason, but neither of these things happens. I need hardly take notice, that when a tooth has lost its opposite it will in time become really so much longer than the rest, as the others grow shorter by abrasion; and I observe that the tooth which is opposite to the empty space becomes in time not only longer, for the above-mentioned reason, but more pointed. The apex falls into the void space, and the two sides are rubbed away against the sides of the two approaching teeth next to that space. The manner of their formation likewise shows that teeth cannot grow beyond a certain limited size. To illustrate this I may ob* serve, that I have often, in the dead body of adults, found the left cuspidatus of the upper jaw with its points scarcely protruding out of the alveolar process though the tooth was completely formed, and longer than the other by the whole point, which in that other was worn away. This tooth, at its first formation, had been deeper SUPERNUMERARY TEETH. 53 in the jaw than what is common; and after it had grown to the ordinary size it grew no longer, though it had not the resistance of the opposite teeth to set bounds to its increase ; yet commonly in these cases the tooth continues to project further and further through the gum, though this is not owing to its growing longer, but to the socket filling up behind it, and thereby continuing to push it out by slow degrees.

Of the Sensibility of the Teeth.

The teeth would seem to be very sensible, for they appear to be subject to great pain, and are easily and quickly affected by either heat or cold. We may presume that the bony substance itself is not capable of conveying sensations to the mind, because it is worn down in mastication, and occasionally worked upon by operators in living bodies, without giving any sensation of pain in the part itself. In the cavity of a tooth it is well known that there is exquisite sensibility, and it is likewise believed that this is owing to the nerve in that cavity. This nerve would seem to be more sensible than nerves are in common, as we do not observe the same violent effects from any other nerve in the body being exposed either by wound or sore, as we do from the exposure of the nerve of a tooth. Perhaps the reason of the intenseness, as well as the quickness of the sense of heat and cold in the teeth, may be owing to their communicating these to the nerve sooner than any other part of the body.*

Of Supernumerary Teeth.

We often meet with supernumerary teeth, and this, as well as some other variations, happens oftener in the upper than in the lower jaw, and, I believe, always in the incisores and cuspidati. I have only met with one instance of this sort, and it was in the upper jaw of a child about nine months old: there were the bodies of two teeth, in shape like the cuspidati, placed directly behind the bodies of the two first permanent incisores, so that there "were three teeth in a row, placed behind one another, viz. the temporary incisor, the body of the permanent incisor, and that supernumerary tooth. The mos't remarkable circumstance was, that these supernumerary teeth were inverted, their points being turned upwards, and bended by

* [That the bony substance of the teeth "is of itself capable of conveying sensation to the mind" is, notwithstanding the author's presumption to the contrary easily proved. Whence otherwise arises that acute sensation so commonly felt when the neck of a tooth is touched with the nail or with any sharp hard instrument, or when a portion of the enamel only is broken from the surface of a tooth * In the latter case every other part of the tooth may be touched without any sensation being produced, but as soon as the instrument comes in contact with the denuded portion of the bone, a painful acute sensation is instantly perceived.] 54 HUNTER ON THE TEETH.

the bone which was above them not giving way to their growth, as the alveolar process does. . , „„__„ It often happens that the incisores and cuspidati, in the upper jaw especially, are so irregularly placed as to give the appearance of a double row. I once saw a remarkable instance of this in a boy; the second incisor on each side was placed further back than what is common, and the cuspidatus and first incisor closer together than if the second incisor had been directly between them, so that the appearance gave an idea of a second row of teeth. This happens only in the adult set of teeth, and is owing to there not being room in the jaw for this second set, the jaw-bone being formed with the first set of teeth, and never increasing afterwards; so that if the adult set does not pass further back, they must overlap each other, and give the appearance of a second row.*

Of the Use of the Teeth, so far as they affect the Voice.

The teeth serve principally for mastication, and that use need not be further explained. . , They serve likewise a secondary or subordinate purpose, giving strength and clearness to the sound of the voice, as is evident from the alteration produced in speaking, when the teeth are lost. This alteration, however, may not depend entirely upon the teeth, but, in some measure, on the other organs of the voice having been accustomed to them ; and therefore when they are gone those other organs may be put out of their common play, and may not be able to adopt themselves so well to this new instrument. Yet I believe that habit in this case has no great effect, for those people seldom or never get the better of the defect: and young children who are shedding their teeth, and are, perhaps, without any fore teeth for half a year or more, always have that defect in their voice till the new teeth come, and as these grow the voice becomes clear again. This use seems to be entirely in the fore teeth, for the loss of one: of these makes a great alteration, and the loss of two or three: grinders seems to have no sensible effect. As an argument for the' use of the teeth in modifying the sound of the voice, we mayf observe, that the fore teeth come at a time when the child begins to articulate sounds, and at that time they are so loose in the gums that they can be of very little service in mastication. Every defect in speech, arising from this defect of the organ, is generally attended with what we call a lisp. People who have lost all their teeth, and most old people for that reason, lose, in a great

* [The occurrence of supernumerary teeth is not at all uncommon, and they are found not as Hunter supposes, only amongst the incisores and cuspidati, but not unfrequently also near the posterior molares. When found near the front of the mouth they also resemble a small and ill-formed cuspidatus, and when near the molares the crown is broader and truncated, somewhat like the neighbouring teeth. It is almost unnecessary to add that the case of irregularity mentioned in the second paragraph is one of very frequent occurrence.] DISEASES OF THE TEETH. 55 measure, their voice. This arises partly from the loss of the fore teeth, but principally from the loss of all the teeth, and of the alveolar processes of both jaws, by which means the mouth becomes too small for the tongue, and the lips and cheeks become flaccid, insomuch that the nicer movements of these parts, in the articulation of sounds are obstructed, and thence the words and syllables are indistinctly pronounced and slurred, or run into one another.

Under what Class do the Human Teeth come.

Natural historians have been at great pains to prove, from the teeth, that man is not a carnivorous animal; but in this, as in many other things, they have not been accurate in their definitions ; nor have they determined what a carnivorous animal is. If they mean an animal that catches and kills its prey with its teeth, and eats that flesh of the prey just as it is killed, they are in the right; man is not in this sense a carnivorous animal, and therefore he has not teeth like those of a lion: and this, I presume, is what they mean. But if their meaning were that the human teeth are not fitted for eating meat that has been caught, killed, and dressed by art, in all the various ways that the superiority of the human mind can invent, they are in the wrong. Indeed, from this confined way of thinking, it would be hard to say what the human teeth are fitted for, because, by the same reasoning, man is not a graminivorous animal, as his teeth are not fitted for pulling vegetable food, &c. They are not made like those of cows or horses, for example. The light in which we ought to view this subject is, that man is a more perfect or complicated animal than any other, and is not made, like others, to come at his food by his teeth, but by his hands, directed by his superior ingenuity, the teeth being given only for he purpose of chewing the food in order to its more easy digestion, md they, as well as his other organs of digestion, are fitted for the inversion of both animal and vegetable substances into blood, and thence he is able to live in a much greater variety of circumstances 1'ian any other animal, and has more opportunities of exercising the faculties of his mind. He ought, therefore, to be considered as a compound, fitted equally to live upon flesh and upon vegetables.

Of the Diseases of the Teeth.

The teeth are subject to diseases as well as other parts of the body. Whatever the disorder is that affects them, it is generally attended with pain; and from this, indeed, we commonly first know that they are affected. Pain in the teeth proceeds, 1 believe, in a great measure from the air comino- in contact with the nerve in the cavity of the tooth, for we seldom see people affected with the tooth-ache but when the cavity is exposed to the air. 56 HUNTER ON THE TEETH. It is not easy to say by what means the cavity comes to be exposed. The most common disease to which the teeth are subject begins with a small dark-coloured speck, generally on the side of the tooth where it is not exposed to pressure; from what cause this arises is hitherto unknown. The substance of the tooth thus discoloured gradually decays, and an opening is made into the cavity. As soon as the air is thereby admitted a considerable degree of pain arises, which is probably owing to the admission of the air, as it maybe prevented by filling the cavity with lead, wax, &c. This pain is not always present; the food and other substances perhaps fill up the hole occasionally, and prevent the access of the air, and of consequence the pain, during the time they remain in it. When an opening is made into the cavity of the tooth the inside begins to decay, the cavity becomes larger, the breath at the same time often acquires a putrid faztor, the bone continues to decay till it is no longer able to support the pressure of the opposite tooth; it breaks and lays the cavity open. We have not as yet found any means of preventing this disease, or of curing it; all that can be done is to fill the hole with lead, which prevents the pain and retards the decay; but after the tooth is broken this is not practicable, and for that reason it is then best to extract it. It would be best of all to attempt the extraction of a tooth by drawing it in the direction of its axis, but that not being practicable by the instruments at present in use, which pull laterally, it is the next best to draw a tooth to that side where the alveolar process is weakest, which is the inside in the two last grinders on each side of the lower jaw, and the outside in all the others. It generally happens in drawing a tooth that the alveolar process is broken, particularly when the grinders are extracted; but this is attended with no bad consequences, as that part of the alveolar process from which the tooth was extracted always decays. In drawing a tooth the patient complains of a disagreeable jarring noise, which always happens when anything grates against the bones of the head.*

From what was said of the nature and use of the enamel, it is evident that whatever is capable of destroying it must be hurtful; therefore all acids, gritty powders, and injudicious methods of scaling the teeth are prejudicial; but simply scaling the teeth, that is clearing them of the stony concretions which frequently collect about their necks, while nothing is scraped off but that adventitious substance, is proper and useful. If not removed by art, the quan-

* [The introduction of forceps of various forms, and of simple elevators, has greatly facilitated the extaction of single-rooted teeth and stumps; but the key instrument must still be acknowledged to be the most certain instrument in many, perhaps in most, cases.] TRANSPLANTING THE TEETH. 57 tity of the stony matter is apt to increase and to affect the gum. This matter first begins to form on the tooth near to the gum; but not in the very angle, because the motion of the gum commonly prevents the accumulation of it at this part. I have seen it cover not only the whole tooth, but a great part of the gum : in this case there is always an accumulation of a very putrid matter, frequently considerable tenderness and ulceration of the gum, and scaling becomes absolutely necessary.*

Of Transplanting the Teeth.

From considering the almost constant variety of the size and shape of the same class of teeth in different people it would appear almost impossible to find the tooth of one person that should fit, with any degree of exactness, the socket of another; and this observation is supported, and indeed would seem to be proved, by observing the teeth in skeletons. Yet we can actually transplant a tooth from one person to another without great difficulty, Nature assisting the operation if it is done in such a way that she can assist; and the only way in which Nature can assist, with respect either to size or shape, is by having the fang of the transplanted tooth rather smaller than the socket. The socket in this case grows to the tooth. If the fang is too large, it is impossible indeed to insert it at all in that state; however, if the fang should be originally too large, it may be made less, and this seems to answer the purpose as well.

* The animal fluids, when out of the course of the general circulation, especially when they stagnate in cavities, are apt to deposit an absorbent earth, and form concretions. This earth is sometimes contained in the fluids, and is only deposited, as in the formation of the stone in the urinary passages; in some cases, perhaps, the fluids undergo a change, by which the earth is first formed, and afterwards deposited. This deposition takes place particularly in weakened parts, or where the circulation is languid, or where there are few arteries, such as about joints and tendons, as if it were intended to strengthen these parts if they should at any time give way : for if an artery, for instance, is overcome by the action of the heart, and unnaturally dilated, its coats have commonly these concretions formed everywhere in their interstices. The same thing happens also in the coats of encysted tumours, which are constantly distended, in cases of distentions of the tunica vaginalis, testis, &c. It is also apt to take place in parts which have lost their natural functions, as in the coats of the eye in cases of blindness, and in diseased lymphatic glands, &c, and where the living power is diminished in the system, as in the arteries, membranes, &c. of old people; and in some particular habits, as in those who are affected by the gout.* The same sort of deposition takes place likewise where there is any substance with such properties as render it a fit basis for crystallization, as when extraneous bodies are lodged in the bladder ; whence such bodies are so often found to form the nucleus of a stone. The same thing happens in the bowels of many animals, whence the nucleus of intestinal concretions, or bezoars, is commonly a nail, or some indigestible substance which had been swallowed. The crust which collects upon the teeth seems to be a crystallization of the same nature.

» [This substance consists, in a very large proportion, of earthy [hosphates, combined with mucus.] 58 HUNTER ON THE TEETH. The success of this operation is founded on a disposition in all living substances to unite when brought into contact with one another, although they are of a different structure, and even although the circulation is only carried on in one of them. This disposition is not so considerable in the more perfect or complex animals, such as quadrupeds, as it is in the more simple or imperfect, nor in old animals, as in young; for the living principle in young animals, and those of simple construction, is not so much confined to, or derived from, one part of the body; so that it continues longer in a part separated from their bodies, and even would appear to be generated in it for some time; while a part, separated from an older or more perfect animal, dies sooner, and would appear to have its life entirely dependent on the body from which it was taken. Taking off the young spur of a cock and fixing it to his comb is an old and well known experiment. I have also frequently taken out the testis of a cock and replaced it in his belly, where it has adhered and has been nourished; nay, I have put the testis of a cock into the belly of a hen with the same effect.* In like manner a fresh tooth, when transplanted from one socket to another, becomes, to all appearance, a part of that body to which it is now attached as much as it was of the one from which it was taken; while a tooth which has been extracted for some time, so as to lose the whole of its life, will never become firm or fixed • the sockets will also in this case acquire the disposition to fill up,' which they do not in the case of the insertion of a fresh tooth. These appearances show that the living principle exists in the several parts of the body, independent of the influence of vhe brain or circulation, and that it subsists by these, or is indebted to them for its continuance; and in proportion as animals have less of brain and circulation the living power has less dependence on them, and becomes a more active principle in itself; and in many animals there is no brain nor circulation, so that this power is capable of being continued equally by all the parts themselves, such animals being nearly similar in this respct to vegetables.!

* [These experiments are related in the Animal (Economy.] t JVThe Pf^V?6 of transPlami"g teeth from one person to another originated, 1 believe, with Hunter, under whose superintendence it was frequently performed. Had the results of all these cases been known to him, it is probable that this recommendation would not have been written; there is not I believe a sinde oy ev™ ftaT £S£ Tof in" "h"' the'e T "^ " »""nVl,a\ten'follS

exposing its continual failure, it/occasiona"Eo^X Zd i'*™",byf correct feeling which seems to be necessarily i„J,olvej in ?,"''S'a,"d lhe Wanik°f tooth figured by Fox as having been the subieot„,t Performance. The collection of Gtry's Hospital Acs L, is ^£&gES%££" " ** DISEASES OF THE TEETH. 59 PART II. INTRODUCTION.

The importance of the teeth is such that they deserve our utmost attention, as well with respect to the preservation of them when in a healthy state, as to the methods of curing them when diseased. They require this attention not only for the preservation of themselves, as instruments useful to the body, but also on account of other parts with which they are connected, for diseases in the teeth are apt to produce diseases in the neighbouring parts, frequently of very serious consequences, as will evidently appear in the following treatise. One might at first imagine that the diseases of the teeth must be very simple, and like those which take place everywhere else in the bony parts of our body; but experience shows the contrary. The teeth, being singular in their structure and some other circumstances, have diseases peculiar to themselves. These diseases, considered abstractedly, are indeed very simple; but by the relations which the teeth bear to the body in general, and to the parts with which they are immediately connected, they become extremely complicated. The diseases which may arise in consequence of those of the teeth are various, such as abscesses, carious bones, &c, many of which, although proceeding originally from the teeth, are more the object of the surgeon than of the dentist, who will find himself as much at a loss in such cases as if the abscess or carious bone were in the leg or any other distant part. All the diseases of the teeth which are common to them with the other parts of the body, should be put under the management of the physician or surgeon, but those which are peculiar to the teeth and their connexions belong properly to the dentist. It is not my present purpose to enumerate every disease capable of producing such symptoms as may lead us to suspect the teeth, for the jaws may be affected by almost every kind of disorder. I shall therefore confine myself to the diseases of the teeth, gums, and alveolar processes ; which parts, having a peculiar connexion, their diseases fall properly within the province of the dentist. I shall also purposely avoid entering into common surgery, so as not to lead the dentist beyond his depth, into matters of which (it is to be supposed) he has not acquired a competent knowledge. In order that the reader may perfectly understand what follows, it will be necessary for him previously to consider and comprehend the anatomy and uses of every part of a tooth, as explained in my 60 HUNTER ON THE TEETH. Natural History of the Human Teeth, to which I shall be obliged frequently to refer. Without such previous study the dentist will often be at a loss to account for many of the diseases and symptoms mentioned here, and will retain many vulgar errors imbibed by conversing with ignorant people, or by reading books in which the anatomy and physiology of the teeth are treated without a sufficient knowledge of the subject. Whichever of the connected parts be originally diseased, the teeth are commonly the greatest sufferers. None of those parts can be distempered without communicating to the teeth such morbid effects as tend to the destruction of them.* CHAPTER I.

OF THE DISEASES OF THE TEETH, AND THE CONSEQUENCES OF THEM.

§ 1. The Decay of the Teeth, arising from Rottenness.

The most common disease to which the teeth are exposed is such a decay as would appear to deserve the name of mortification. But there is something more; for the simple death of the part would produce but little effect, as we find that teeth are not subject to putrefaction after death, and therefore I am apt to suspect, that during life there is some operation going on which produces a change in the diseased part. It almost always begins externally in a small part of the body of the tooth, and commonly appears at first as an opaque white spot. This is owing to the enamel's losing its regular and crystallized texture, and being reduced to a state°of powder,

* [The object of the author in writing this work, as given in the introduction to the second part, was indeed worthy of himself. That the dentists of his day required such information as he professes to give them, nearly as much as those of the present, may be fairly inferred ; but it also may be reasonably asked, how he unfortunate dent.st who is supposed by our author not to have acquired a knowledge of common surgery, as " a matter beyond his depth," is to understand the diseases « which are peculiar to the teeth and their connexions,-" as if abscess, ulceration, tumours, caries, necrosis, &c, are lobe readily understood bv the charlatan who knows nothing of the principles of common urterv'when they occur in the gums and a veo ar processes -whilst if u i ° 7 • , y pans of the fody, «hey fall within ST roVhnt" ' L'^e r. ^Had'Hon er endeavoured to rescue the surgical treatment nf iha T ,"T»fon- ,Haa„ «unier hands of the mere mechanic, *tino££™£iJ£Z^ altogether from the of professional knowledge upon the°notic«o"the scientific „« 1??re8tln|f Portl°n have done more to raise it from its present dearaflS 1 PractlUoner> ,,e would power of a less influential author toXt; agnd w^oild noT" °T ^l"?* deplore, in his own quaint but expressive words that ZHt TZ hVAh*d t0 a loss to account for many of these diseases aKll, f. S Sh°U,d be "at vulgar errors imbibed by conversing witM^reTpeJpT"] " "^ "^ DECAY OF THE TEETH, ETC. 61 from the attraction of cohesion being destroyed, which produces similar effects to those of powdered crystal. When this has crumbled away, the bony part of the tooth is exposed; and when the disease has attacked this part, it generally appears like a dark brown speck. Sometimes, however, there is no change of colour, and therefore the disease is not observable till it has made a considerable hole in the tooth. The dead part is generally at first round, but not always, its particular figure depending more on the place where it begins than on any other circumstance. It is often observed on the hollow parts of the grinding surface of the molares, and there looks like a crack filled with a very black substance. In the incisores the disease usually begins pretty near the neck of the tooth, and the scooping process goes on enlarging the cavity, commonly across the same part of the tooth, which almost divides it into two. When such a diseased tooth gives way, the mischief is occasioned by its body breaking off. When it attacks the bony part it appears first to destroy the earth ; for the bone becomes softer and softer, and is at last so soft on the exterior exposed surface that it can be picked away with a pin, and when allowed to dry it cracks like dried clay. It begins sometimes in the inside of the tooth, although but rarely. In this case the tooth becomes of a shining black, from the dark colour being seen through the remaining shell of the tooth, and no hole is found leading into the cavity. This blackness is seldom more than a portion of the bony part decayed or mortified. However, it often happens that the remaining part of the tooth becomes simply dead, in which state it is capable of taking on a dye. As it is generally on the external surface, one might expect no great mischief would ensue; but the tendency to mortification goes deeper and deeper, till at last it arrives at the cavity of the tooth, and the mortification follows. Mortification is common to every part of the body; but in most other parts this tendency is owing in a great measure to the constitution, which being corrected, that disposition ceases; but here it is local, and as such it would appear that we have no power of resisting it. When gone thus far the decay makes a quicker progress, similar to those cases where the decay begins in the cavity; for then this disposition is given to the whole cavity of the tooth, which being a much larger surface than what the disease had before to act upon, the increase of the decay seems to be in the same proportion; at last it scoops out its inner substance, till almost nothing is left but a thin shell, which generally being broken by mastication, a smaller or larger opening is made, and the whole cavity becomes at length exposed. The canal in the fang of the tooth is more slowly affected; the scooping process appears to stop there, for we seldom know a fang become very hollow to its point when in the form of a stump; and it sometimes appears sound, even when the body of the tooth is almost destroyed: hence I conclude that the fang of the tooth has greater living powers than the body, by which the process of the 62 HUNTER ON THE TEETH. disease is retarded; and this part appears at last only to lose its living principle, and not to take on the mortifying process above described; for which reason it remains simply a dead fang; however, it does not remain perfectly at rest." This is the stage in which it is called a stump. It begins now to lose its sensibility, and is seldom afterwards the cause of pain. Thus, in appearance, it will remain sometimes for many years, but there will be more or less of a change going on ; Nature will be attempting to make up the deficiency by endeavouring to increase the stump; for in many cases we find the stumps thickened and lengthened at their terminations, or small ends; but it is a process she is not equal to, therefore no advantages accrue from it. When she either fails in this process, or is in such a state as not to attempt it, then by this condition of the tooth a stimulus is given to the alveolar processes which produces a filling up of the socket from the bottom, whereby the stumps are gradually protruded. But although they are pushed out at the bottom, they seldom or never project further beyond the gum than at first; and that part of the tooth which projects seems to decay in proportion to its projection. Besides this decay at the external end of the stump, there is an absorption of the fang at the bottom, which is known by the following observation: the end of the stump, which was in the gum or jaw, becomes irregularly blunted, and often rough, and has not the appearance of the end of the fang of a sound tooth. Such stumps are in general easily extracted, being attached often to little more than the gum, and that sometimes loosely. Although the disease'appears to be chiefly in the tooth itself, and but little to depend on external causes, yet in many cases the part which is already rotten seems to have some influence upon that which remains; for if the rotten part be perfectly removed before it has arrived at the canal of the tooth, a stop is sometimes put to the further progress of the decay, at least for a time. However, this is not constantly so; it is oftener the contrary; but it is expedient in most cases to make this trial, as it is always right to keep a tooth clean and free from specks. This decay of the teeth does not seem to be so entirely the effect of accident as might be imagined; for it sometimes takes place in them by pairs, in which case we may suppose it owing to an original cause coming into action at its stated time; the corresponding

tTo^shTpf, &cP.airS reSp6Ct t0 thG diseaSG' as Wel1 as t0 situa'

lowef iat"not ll^ewh^^S^ened by the fore teeth in the alhou^a^ decay as tho*e i" the upper, ence S accidents arising from external influmi wmcn could Proa-uce the disease in general The fore teeth in the lower jaw aPpea?to be iess subject to this

* [The mortification and simple death of n ,M.( , On this object the reader is referred to the ^2/K%^^rent thinSS" DECAY OF THE TEETH, ETC. 63 disease than any of the others ; the fore teeth in the upper jaw, and the grinders in both, are of course more frequently affected. This disease and its consequences seem to be peculiar to youth and middle age ; the shedding teeth are as subject to it, if not more so, than those intended to last through life; and we seldom or ever see any person whose teeth begin to rot after the age of fifty years. This might be supposed to arise from the disproportion that the number of teeth after fifty bear to them before it; but the number of diseased teeth after fifty do not bear the same proportion. This disease has not hitherto been accounted for: if it had been always on the inside of the cavity, it might have been supposed to be owing to a deficiency of nourishment from some fault in the vascular system ; but as it begins most commonly externally, in a part where the teeth in their most sound state receive little or no nourishment, we cannot refer it to that cause. It does not arise from any external injury, or from menstrua, which have a power of dissolving part of a tooth ; for anything of that kind could not act so partially: and we can observe in those teeth where the disease has not gone deep, that from the black speck externally there is a gradual decay or alteration leading to the cavity, and becoming fainter and fainter. We may therefore reasonably suppose that it is a disease arising originally in the tooth itself; because when once the shell of the tooth has given way to the cavity, the cavity itself soon becomes diseased in the same way. That the disease spreads thus rapidly over the cavity as soon as the tooth has given way does not depend simply on the exposure; for if a sound tooth be broken by accident, so as to expose the cavity, no such quick decay ensues; however, sometimes we find in those cases that exposure of the cavity will produce a decay, and even pain, similar to an original disease; and in the diseased tooth we find that the exposure has a considerable effect in hastening the progress of the disease; for if the tooth be stopped so as to prevent its exposure to external injury, its cavity will not nearly so soon become diseased. Exposure, therefore, seems at least to assist the decay. How far a rotten tooth has the power of contaminating those next to it, I believe, is not yet completely ascertained ; some cases seem to favour this idea, and many to contradict it. We frequently see two teeth rotten in places exactly opposite to each other, and as one of them began first to decay, it gives a suspicion that the last diseased was infected by that which received the first morbid impression. On the contrary, we often see one diseased, whilst another tooth, in contact with the decayed part, remains perfectly sound.*

* [The reasoning which we find in the preceding section is not only inconclusive, but in many parts not wholly consistent with itself. Nor is it possible, with the vague notions entertained hy Hunter, and even by some in the present day, who follow his words rather than his spirit respecting the peculiar character of the bony structure of these organs, to form a rational and consistent 64 HUNTER ON THE TEETH. Symptoms of Inflammation.

Few or no symptoms are produced by this disease besides the above appearances till the cavity of the tooth is exposed : however, it often happens that a tenderness, or a soreness upon touch, or other external influences, takes place long before; but when the cavity is exposed, then pain and other symptoms often begin, which are generally very considerable: however, the exposure of the cavity of a tooth does not in all cases give pain. Some teeth shall moulder wholly away without ever having any sensation. In many cases there will be very acute pain upon the cavity being exposed, which will subside and recur again without producing any other effect; but it more frequently happens that this pain is the first symptom of inflammation, and is in most cases very considerable, more so than that arising from such an inflammation in other places. The surrounding parts sympathize commonly to a considerable extent, viz. the gums, jaw-bones, and integuments covering them; they inflame and swell so much as to affect the whole of that side of the face where the affected tooth is situated. The mouth can hardly be opened ; the glands of that side of the neck often swell; there is an increase of the saliva, and the eye is almost closed, the tooth not giving way to the swelling of the soft parts within it; and for this reason the local effects of the inflammation cannot be so visible as in the soft parts.

opinion on this difficult subject. Fox appears to have made an approach towards the truth; but by assuming the absolute identity of structure in the teeth and true bones, without taking into the account their remarkable and acknowledged discrepancies, he fell into the opposite error, of expecting to find in the morbid affections of the teeth the analogue of every disease to which the more highly organized bones are liable. The opinion that decay of the teeth is communicable by contact is now fast becoming obsolete. That we often see two teeth becoming decayed " at places exactly opposite to each other," as observed by Hunter, is a matter of almost proverbial notoriety; but it is not, I believe, difficult to account for this fact, without assuming a doctrine so inconsistent with all that is known of the structure no less than of the chemical composition of these organs. As the enamel, when perfect, not only prevents the wearing away of the teeth by mastication, but also protects that part which is out of the gum from external cause of irritation and decay, whatever should tend to injure that substance and destroy the unity of its texture would be likely to occasion decay of the subjacent bony substance. When two teeth, therefore, are very strongly pressed together, either during their growth or afterwards, the crystallized structure of the enamel is frequently broken down, or at least the continuity of its texture injured, to such a degree as to admit of those external causes of inflammation and of subsequent loss of vitality which have just been alluded to. This would occur at the point of contact, and hence the frequency of the occurrence of this disease at that part. The prevalence of decay in contiguous teeth may also be accounted for by attributing it in both to the same general exciting cause, as cold, mechanical injury, &c. And, on the other hand, it appears impossible to imagine infection taking place through a substance so entirely inorganic, so dense, and so perfect and uniform in its structure, as this crystallized enamel. To which it may be added, that there is no chemical agent evolved during the decay of a tooth which can decompose this substance Notwithstanding the absurdity of the opinion, however, it is probable that at the time when Hunter wrote the doubt expressed in the text he was the onlvrnan in the profession who ventured to entertain such a doubt.] y SYMPTOMS OF INFLAMMATION. 65 This inflammation of the tooth often lasts a considerable time, and then gradually subsides. We may suppose, according to the general lawr of inflammation, that it is at first of the adhesive kind, and accordingly we sometimes find the teeth swelled at their ends, which is a character of the adhesive stage of inflammation ; and sometimes two fangs are grown together. That we seldom find adhesions between the teeth and surrounding parts may be reasonably imputed to their less aptitude for such connexions. The suppurative inflammation succeeds ; but as a tooth has not that power of suppuration which leads to granulations, so as to be buried, covered up, and made part of ourselves, as happens to other bones (which would destroy any use of a tooth), the inflammation wears out, or rather the parts not being susceptible of this irritation beyond a certain time, the inflammation gradually goes off, and leaves the tooth in its original diseased state. No permanent cure, therefore, can possibly be effected by such inflammations ; but the part being left in the same state as before, they are still subject to repetitions of inflammation till some change takes place, preventing future attacks, which I believe is generally, if not always, affected by the destruction of those parts which are the seat of it, viz. the soft parts within the tooth. Nature seems in some measure to have considered the teeth as aliens, only giving them nourishment while sound and fit for service, but not allowing them when diseased the common benefits of that society in which they are placed. They cannot exfoliate, as no operations go on in them except growth ; therefore, if any part is dead, the living has not. the power of throwing it off, and forming an external surface capable of supporting itself, like the other parts of the body: indeed, if they had such a power no good purpose could be answered by it; for a piece of tooth simply dead is almost as useful as if the whole was living; which may be observed every day. The pain, however, appears to take its rise from the tooth as a centre. That it should be more severe than what is generally produced by similar inflammations in other parts of the body, may, perhaps, be accounted for when we consider that these parts do not readily yield; as is likewise the case in whitloes. It sometimes happens that the mind is not directed to the real seat of the disease, the sensation of pain not seeming to be in the diseased tooth, but in some neighbouring tooth which is perfectly sound. This has often misled operators, and the sympathizing tooth has fallen a sacrifice to their ignorance. In all cases of diseased teeth the pain is brought on by circumstances unconnected with the disease ; as, for instance, cold, wherefore they are more toublesome commonly in winter than in summer. Extraneous matter entering the cavity, and touching the nerve and vessels, will also bring on the pain. This pain is frequently observed to be periodical; sometimes there being a perfect intermission, sometimes only an abatement of it, 66 HUNTER ON THE TEETH. The paroxysm comes on once in twenty-four hours, and for the most part towards the evening. The bark has therefore been tried; but that failing, the disorder has been suspected to be of the rheumatic kind, and treated accordingly with no better success. At length, after a more particular examination of the teeth, one of them has been suspected to be unsound; and, being extracted, has put an end to the disorder. This shows how injudicious it is to give medicines in such cases, while the true state of the tooth is unknown. This disease is often the cause of bad breath, more so than any other disease of those parts, especially when it has exposed the cavity of the tooth. This most probably arises from the rotten part of the tooth and the juices of the mouth and food all stagnating in this hollow part, which is warm, and hastens putrefaction in them. I come now to the prevention and cure of this disease. The first thing to be considered is the cure of the decaying state of the tooth, or rather the means of preventing the further progress of the decay; and more especially before it has reached the cavity, whereby the tooth may be in some degree preserved, the consequent pain and inflammations, commonly called tooth-ache, avoided, and often the consequent abscesses called gum-boils. I believe, however, that no such means of absolute prevention are as yet known. The progress of the disease, in some cases, appears to have been retarded by removing that part which is already decayed ; but experience shows that there is but little dependence upon this practice. I have known cases where the black spot having been filed off and scooped entirely out, the decay has stopped for many years. This practice is supposed to prevent at least any effect that the part already rotten may have upon the sounder parts; however, if this is all the good that arises from this practice, I believe in most cases it might be as well omitted. Even if it were an effectual practice, it could not be an universal one; for it is not always in the power of the operator to remove this decayed part, either on account of its situation, or on account of its having made too great a progress before it is discovered. When it is on the basis of a grinder, or on the posterior side of its neck, it can scarcely be reached. It becomes also impracticable when the disease is still allowed to go on, and the cavity becomes exposed, so that the patient is now liable to all the consequences already described, and the tooth is making haste towards a total decay; in such a case, if the decay be not too far advanced, that is, if ,t be not rendered useless simply as a tooth, I would advise that it be extracted, then immediately boiled, with a view to make it perfectly clean, and also destroy any life there may be in the tooth; and then that it be restored to the socket this will prevent any further decay of the tooth, as it is now dead', and

«tnSnyUP°n ^ ^ dlS6aSe' bUt Can °»'y «** chemically This practice, however, I would only recommend in grinders, SYMPTOMS OF INFLAMMATION. 67 where we have no other resource on account of the number of fangs, as will be more fully explained hereafter. This practice has sometimes been followed with success; and when it does succeed, it answers the same end as the burning the nerve, but with much greater certainty. If the patient will not submit to have the tooth drawn, the nerve may be burned: that this may have the desired effect, it must be done to the very point of the fang, which is not always possible. Either of the concentrated acids, such as the sulphuric, the nitric, or the muriatic, introduced as far into the fang of the tooth as possible, is capable of destroying its soft parts, which most probably are the seat of pain: a little caustic alkali will produce the same effect. But it is a difficult operation to introduce any of these substances into the root of the fang, till the decay has gone a considerable length, especially if it be a tooth of the upper jaw ; for it is hardly possible to make fluids pass against their own gravity; in these cases, the common caustic is the best application, as it is a solid. The caustic should be introduced with a small dossil of lint, but even this will scarcely convey it far enough. If it be the lower jaw, the caustic need only be introduced into the hollow of the tooth, for by its becoming fluid, by the moisture of the part, it will then descend down the cavity of the fang, as will also any of the acids; but patients will often not suffer this to be done till they have endured much pain and several inflammations. When there is no other symptom except pain in the tooth, we have many modes of treatment recommended, which can only be temporary in their effects. These act by derivation, or stimulus applied to some other part of the body. "Thus, to burn the ear by hot irons has sometimes been a successful practice, and has relieved the tooth-ache. Some stimulating medicine, as spirit of lavender, snuffed up into the nose, will often carry off the pain. When an inflammation takes place in the surrounding parts, it often is assisted by an additional cause, as cold or fever: when the inflammation has taken place in a great degree, then it becomes more the object of another consideration; for it may be lessened like any other inflammation arising from similar causes, the pressure of an extraneous body, or exposure of an internal cavity. If the inflammation be very great, it will be proper to take away some blood. The patient may likewise properly be advised to hold some strong vinous spirit for a considerable time in his mouth. Diluted acids, as vinegar, &c, may likewise be of use, applied in the same manner. Likewise preparations of lead would be advisable ; but these might prove dangerous if they should be accidentally swallowed. If the skin is affected, poultices, containing some of the abovementioned substances, produce relief. The pain in many cases being often more than the patient can well bear, warm applications to the part have been recommended, such as hot brandy, to divert the mind; also spices, essential oils, &c, which last are, perhaps, 68 HUNTER ON THE TEETH. the best. A little lint or cotton soaked in laudanum is often applied with success ; and laudanum ought likewise to be taken internally to procure an interval of some ease. Blisters are of service in most inflammations of these parts, whether they arise from a diseased tooth or not. They cannot be applied to the part, but they divert the pain and draw this stimulus to another part; they may be conveniently placed either behind the ear or in the nape of the neck. These last-mentioned methods can only be considered as temporary means of relief, and such as only affect the inflammation. Therefore the tooth is still exposed to future attacks of the same disease.*

* [In the foregoing passages there is much important and accurate observation evinced in the description of the symptoms either attending or succeeding inflammation in the teeth. There are, however, apparently no less than three distinct diseases confounded in this description. The first is the inflammation produced by the exposed pulp from decay of the tooth; the second, suppuration of the pulp, which often takes place independently of exposure; and the third, the inflammation and suppuration of the surrounding parts, which as frequently occur from the irritation produced by the existence of dead teeth or roots in the socket (as extraneous bodies) as from any other cause. Many of the remarks on the treatment of these affections are replete with sound sense, and have undoubtedly laid the foundation for the best modes of practice in use since that day. A few observations of a more detailed nature may not, however, be wholly useless. When the disease termed caries, or more properly gangrene, has only just commenced under the enamel, so as only to exhibit the appearance of a brown opake mark, there can be no doubt that the entire excision of the spot will much retard the progress of decay by removino- one cause of irritation to the surrounding healthy bone; but if the decay has extended to any distance from the surface, the file must be used to such an extent, in order to remove the whole of the diseased portion, as to expose a considerable part of the bone to external irritants, and consequently will hasten rather than retard the mischief. The replacement of a decayed tooth after extraction, beino- first of all boiled to destroy its vitality, is recommended by Hunter only theoretically. An obvious and insurmountable objection exists to this operation, which is, that a dead extraneous body is thus forced into the alveolus, still sore from the operation, which must necessarily produce much irritation, and often suppuration, with all those severe symptoms which so often arise from-dead roots, or from teeth whose connexion with the socket has been destroyed by a blow. The burning of the nerve is deserving of no better eulogy than the operation just mentioned. Hunter himself observes, with much naivete, that » it must be done to the very point of the fang, which is not always possible."* The truth k that burning the pulp of a tooth even superficially, to be of service at all, must be done whenthe cauterizing wire is at a white heat, or it otherwise only produces inflamnjft.on, and not the instantaneous destruction of the surface ; but when the small size of the instrument, the distance which it must necessarily pass before it is brought into contact with the pulp, and the time which must e apse before it is applied, are considered, the imp^ss bil tyo ™ffelally em ploying this remedy is obvious. The other remedies here allied to andI £<£d all other caustic applications, are generally productive nf mnrl; \i u £ and exacerbate rather than diminish their inflammation JdnanJU^ I ' gative medicines, and the local application of narcoSC nf u ^ PUu often be beneficial; but, the pulp beinff once exnll, ' I ca,mPhor' &c-< wl11 afford can be but temporary, and the onl/reiSy SKift rel,ef wh>ch these tion of the tooth.] J y t0 be relled upon is the extrac- STOPPING OF THE TEETH. 69 The Stopping of the Teeth.

If the destruction of the life of the tooth, either by drawing and restoring it again, or by the actual or potential cauteries, has not been effected, and only the cure of the inflammation has been attempted, another method of preventing inflammation is to be followed, which is to allow as little stimulus to take place as possible. The cavity of the tooth not being capable of taking the alarm like most other cavities in the body, and of course not suppurating, as has been already observed, often no more is necessary, either to prevent the inflammation from taking place altogether, or extending further, than to exclude all extraneous irritating matter; therefore the stopping up the cavity becomes, in many cases, the means of preventing future attacks of the inflammation, and often retards even the progress of the disease, that is, the further decay of the tooth, so that many people go oh for years thus assisted: but it is a method which must be put in practice early, otherwise it cannot be continued long; for if the disease has done considerable damage to the inside of the tooth, so as to have weakened it much, the whole body of the tooth most probably will soon give way in mastication: therefore, under such circumstances, the patient must be cautioned not to make too free with the tooth in eating. Gold and lead are the metals generally made use of for stopping teeth. Gold being less pliable must be used in the leaf; lead is so soft in any form as to take on any shape by a very small force. Stuffing the hollow tooth with wax, galbanum, &c. can be but of very little service, as it is in most cases impossible to confine these substances, or preserve them from being soon worn away; however, they have their uses, as it is a practice which the patients themselves can easily put in execution. It often happens from neglect, and much oftener in spite of all the means that can be used, that the tooth becomes so hollow as to give way, whereby the passage becomes too large to keep in any of the above-mentioned substances; however, in this case, it sometimes happens that a considerable part of the body of the tooth will still stsmd, and then a small hole may be drilled through this part, and after the cavity has been well stopped, a small peg may be put into the hole, so as to keep in the lead, gold, &c. But when this cannot be done, we may consider the broken tooth as entirely useless, or at least it will soon be so; and it is now open to attacks of inflammation, which the patient must either bear, or submit to have the tooth pulled out. If the first be chosen, and the repeated inflammations submitted to, a cure will be performed in time by the stump becoming totally dead; but it is better to have it pulled out, and suffer once for all. Upon pulling out these teeth we may in general olpterve a pulpy substance at the root of the fang, so firmly adhering to the fang as to be pulled out with it. This is in some pretty large, so as to have made a considerable cavity at the bottom of the socket- This 8 70 HUNTER ON THE TEETH. substance is the first beginning of the formation of a gum-boil, as it at times inflames and suppurates.*

§ 2. The Decay of the Teeth by Denudation.

There is another decay of the teeth, much less common than that already described, which has a very singular appearance. It is a wasting of the substance of the tooth very diflerent from the former. In all the instances I have seen, it has begun on the exterior surface of the tooth, pretty close to the arch of the gum. The first appearance is a want of enamel, whereby the bony part is left exposed, but neither the enamel nor the bony part alters in consistence as in the above-described decay. As this decay spreads, more and more of the bone becomes exposed, in which respect also it differs from the former decay; and hence it may be called a denuding process. The bony substance of the teeth also gives way, and the whole wasted surface has exactly the appearance as if the tooth had been filed with a rounded file, and afterwards had been finely polished. At these places the bony parts, being exposed become brown. I have seen instances where it appeared as if the outer surface ot the bony part, which is in contact with the inner surface of the enamel had first been lost, so that the attraction of cohesion between the two had been destroyed, and as if the enamel had been separated for want of support, for it terminated all at once In one case, the two first incisors had lost the whole of the enamel; on their anterior surfaces they were hollowed from side aJha'/tl if r°andrfi,!e.had been aPP^d to them longitudinally, and had the finest polish imaginable. The three grinders on each

tfarvTe^t ^t^/0^! ^ had been Used on ^em in a con o thyeturn soth^t ih1 °n thG incisors'viz- ^oss their bodies close to the gum, so that there was a groove running across their bodies,

day^rwafatl&Jh^f f ^ ^ -derstood in the present wifhstandingThe numerus extmen's wlThf ^T^ 7™ T'^ Not" able quack nostrums which ha^Tbee^trod nee? ^Z^V"* *l i™"™'

whichfOTdo»bRi^ pastes, cements or fncsihlo m««„n- ^ . l0 Pure g°Jd- All the amalgams, plausible, h^i^^^^rTS1' sre of ^v<^~ and some feW cases partially succeed w£ a totr!°l m,fntfth^ they may not in

w/th ^^^^l^^^^ ^e progress of decay operation should be had recou^to as sooasZ* ^ fXp°Sed' In fact the ear her, and the decayed part can be drilledUutnfTT1 u3S glVen wa?' or even still further the decayed portion must beenTf t0°th' When il has gone struments adapted to this purpose, and 15 r,emoved bY means of little ingold, beaten of a proper thickness, is to be ca?Jft U S m?de Per^tly dry, the it is completely and solidly filled.] ca'efully pressed into the cavity until SWELLING OF THE FANG. 71 which was smooth in the highest degree. Some of the other teeth in the same jaw had begun to decay in a similar manner; also the teeth in the lower jaw were become diseased. I saw a case very lately where the four incisors of the upper jaw had lost their enamel entirely on their anterior surfaces, and there was scarcely a tooth in the mouth which had not the appearance of having had a file applied across it close to the gum. Those whom I have known have not been able to attribute this disease to any cause; none of them had ever done anything particular to the teeth, nor was there in appearance anything particular in the constitution which could give rise to such a disease. In the first of these cases the person was about forty; in the last about twenty years of age. From its attacking certain teeth rather than others in the same head, and a particular part of the tooth, I suspect it to be an original disease of the tooth itself, and not to depend on accident, way of life, constitution, or any particular management of the teeth.*

§ 3. The Swelling of the Fang.

Another disease of the teeth is a swelling of the fang, which most probably arises from inflammation, while the body continues sound, and is of that kind which in any other bone would be called a spina ventosa.f It gives considerable pain, and nothing can be seen externally. The pain may either be in the tooth itself or the alveolar process, as it is obliged to give way to the increase of the fang. As a swelling of this "kind does not tend to the suppurative inflammation, and as I have not been able to distinguish its symptoms from those of the nervous tooth-ache, it becomes a matter of some difficulty to the operator; for the only cure yet known is the extraction of the tooth, which has been often neglected on a supposition that the pain has been nervous. These diseases of the teeth, arising from inflammation, become often the cause of the diseases in the alveolar processes and gums, which I shall proceed to describe. J

* [I have elsewhere mentioned a very curious case of an affection somewhat analogous to that here described. It consisted of the gradual truncation of the edges°of the front teeth, both of the upper and lower jaw, extending back to the bicuspides. The exposed surface was perfectly smooth and polished, and the loss of substance extended so far that the cavities of the teeth must have been opened, but that they had become filled with a new solid bony substance, so transparent that it was only by touching it that its presence was ascertained. As the teeth never could have come in contact at the truncated part, and as no mechanical means had ever been used by which it could have been occasioned, the cause of this singular affection remains wholly unknown.] | [Natural History of the Teeth, p. 23.] £ [The affection here described is nothing more than a deposit of bony matter around the fang, produced, doubtless, by inflammation of the periosteum. The new bone is rather yellower and less opaque than the original structure. Hunter has alluded here to the occurrence of nervous pains, produced by these cases._ It appears probable that the pressure of the new bone upon the nerves of the perios- 72 HUNTER ON THE TEETH. § 4. Gum-Boils. Although suppuration cannot easily take place within the cavity of a tooth, yet it often happens that the inflammation which is extended beyond it is so great as to produce suppuration in the jaw at the bottom of the socket where the diseased tooth is, forming there a small abscess, commonly called a gum-boil. This inflammation is often very considerable, especially when the first suppuration takes place. It is often more diffused than inflammations in other parts, and affects the whole face, &c. The matter, as in all other abscesses, makes its own way outwards, and as it cannot be evacuated through the tooth, it destroys the alveolar processes, and tumifies the gum, generally on the fore part, either pointing directly at the root of the tooth, or separating the gum from it, and is evacuated in one or other of these two ways, seldom on the inside of the gum; however, this sometimes happens' Gum-boils seldom arise from other causes; however, it sometimes happens that they originate from a disease in the socket or jaw, having no connexion with the tooth, and only affecting it secondarily. Upon drawing such teeth, they are generally found diseased at or near the point, being there very rough and irregular similar to ulcerating bones. There is no disease To appearance in the body of the tooth. These last-described gum-boils may arise

retgyonraneffecat.CaUSe' ^ *V*»™<» °n ^ fan* °f the t00th These abscesses, whether arising from the teeth or the sockets a ways destroy the a veolar processes on that side where they open;

a counTt^e ^fhT W ^ ^T* °f mM* SCulls^ on "wE account the tooth becomes more or less loose. It may be perceived in the living body; for when the alveolar procesTX enSSy de stroyed on the outside of the tooth, if that tooth be moved the motion will be observed under the gum along the whole lengthIf

by^onsent1!6 ^^ alVG°lar Processes' and S»™ become diseased

ancet'arThis^,11168!-^TS t0 ?kin over' and in ah appearh HU7 J iJV- Pu CUhar t0 those which °Pen through the Sumscan nevei til tvt^ ^P"1™ betweem the ^ms and'S howeve"the^disch'arll^f. ^ F™ C™UOt Unite ™th the tooth;

teum of the alveolus, or of the alveolar process itself ia ,1. for it cannot be distinguished from local EeuXsl !i *?e °ause of this Pain« cause Cases of this description are detailed ^bv ^"1 ty *a* 0ther similar the only method by which the true seat of nj? fW by myself, in which striking the affected tooth, by which pa „ WaPS urnT*a ** ascen™e* was by the tooth at once exhibited the cause of the JLP»„.Tff '* *?d the extraction of F In and effected its cure.] GUM-BOILS. 73 skin over. But either exposure to cold, or some other accidental cause, occasioning a fresh inflammation, produces an increased suppuration, which either opens the old orifice in the gum, or augments the discharge by the side of the tooth; however, I believe, the inflammation of this last case is not so violent as in the other, where a fresh ulceration is necessary for the passage of the matter. Thus a gum-boil goes on for years, healing and opening alternately; the effect of which is that the alveolar processes are at length absorbed, and the tooth gets looser and looser, till it either drops out or is extracted. Most probably in all such cases the communication between the cavity of the tooth and the jaw is cut off; yet it keeps in part its lateral attachments, especially when the gum grasps the tooth: but in those cases, where the matter passes between the gum and the tooth, these attachments are less; but some of them are still retained, particularly on the side opposite to the passage for the matter. Gum-boils are easily known. Those which open through the gum may be distinguished by a small rising between the arch of the gum and the attachment of the lip; upon pressing the gum at the side of this point, some matter will commonly be observed oozing out at|the eminence. This eminence seldom subsides entirely; for even when there is no discharge, and the opening is healed over, a small rising may still be perceived, which shows that the gumboil has been there. Those gum-boils which discharge themselves between the gum and the tooth are always discovered by pressing the gum, whereby the matter is pressed out, and is seen lying in the angle between the gum and tooth. These abscesses happen much more frequently in the upper jaw than in the lower, and also more frequently to the cuspidati, incisores, and bicuspides in that jaw than to the molares; seldom to the fore teeth in the lower jaw. As gum-boils are in general the consequence of rotten teeth, we find them in young and middle-aged people more frequently than in old; but they appear to be most common to the shedding teeth. This will arise from those teeth being more liable to become rotten; and perhaps there may be another reason, viz. the process of ulceration which goes on in these teeth,*- in some cases falling into suppuration. It sometimes happens in these gum-boils that a fungus will push out at the orifice, from a luxuriant disposition to form granulations in the inside of the abscess, and the want of power to heal or skin; the same thing frequently happens in issues, where the parts have a disposition to granulate, but have not the power of healing, on account of an extraneous body being kept there. The tooth in the

* Vide Natural History of the Teeth, for an explanation of this process in those teeth, p. 47. 8* 11 HUNTER ON THE TEETH. present case acts as an extraneous body, and by the secretion of matter the abscess is prevented from healing. In the treatment of gum-boils, the practice will be the same, whether the abscess has arisen from a diseased tooth, or a disease in the socket. The teeth being under such circumstances in the animal machine that they cannot partake of all the benefits of a cure in the same manner as other parts do, on that account, when an abscess forms itself about the root of a tooth, the tooth, by losing its connexion with the other parts, loses every power of union, as it is not endowed with the power of granulating, and thereby it becomes an extraneous body, or at least acts here as an extraneous body, and one of the worst kind, such as it is not in the power of any operation of the machine to get rid of. This is not the case with any other part of the body, for when any other part becomes dead, the machine has the power of separating it from the living, called sloughing or exfoliation,and expelling it, whence a cure is effected; but in the case of gum-boils the only cure of them is the extraction of the tooth. As this is the last resource, everything is to be done to make the parts as easy under the disease as possible, so that this operation may be postponed. When the abscess has opened through the gum, I believe the best method that can be tried with a view to prevent future gatherings is to prevent the closing up of the abscess; and this may be done by enlarging the opening, and keeping it enlarged till the whole internal surface of the cavity of the abscess is skinned over, or till the opening in the gum loses the disposition to close up, which will in a great meas,]re prevent any future formation of matter, or a eas

rccumdatio^T601 ?l*ad fn *** °Utlet> which wil1 P™ent these accumulations from taking place ever after. The end of the fang

rJo be ^nl trsT^f "W b,\Under SUch circumstances it 3 not be in a woise situation than when soaked in matter.

tilled water- anH fh! diaJiim of the caustic in two ounces ofdis-

One considerable disadvantao-P r^™,. • .. • the difficulty of keeping onthe'Te^ZhV^ PraCtiCG' which ''S make up for the inconvenience o < uf ion constant attention will If the surface of the abscess be tm\n\ a ■ , and the lip kept from comingi, cSf d^||h Jhe potassa fusa, minute, it answers better than anv V h the Part for one that space of time, will penetrate to thl h ™ethod'> for this, within The surface of >he J, should\e t, fe,ry as , , Pea ar>»as much as the EXCRESCENCES FROM THE GUM. 75 nature of the part will allow, to prevent as much as possible the spreading of the caustic, which by care can be prevented, as the operator will watch it the whole time. To extract the tooth, then to file off any diseased part of it, and immediately to replace it, has been practised, but often without the desired success ; for it has often happened that a tooth has been introduced into a diseased jaw. This practice, however, now and then has succeeded. When a gum-boil is formed on a back or molar tooth, such very nice treatment is not necessary as when it happens to the fore teeth, because appearances are there of less consequence; therefore the gum may be slit down upon the fang through its whole length, from the opening of the gum-boil to its edge, which will prevent any future union ; and the whole cavity of the abscess skinning over will prevent any future collection of matter. The wound appears afterwards like the hare lip, and therefore this practice is not advisable where it would be much in view, as when the disease is in the fore teeth. In these cases, where the granulations push out through the small opening, they may be cured by the method above mentioned; but if it is not complied with, they may be very safely cut off with a knife or lancet. However, this does not effect a cure, for they commonly rise again. To slit the gum in this case has been common, but it is a bad method whenever the defect is in sight.*

§ 5. Excrescences from the Gum.

From bad teeth there are also sometimes excrescences arising at once out of the gum, near, or in contact with, the diseased tooth. In general they are easily extracted with a knife, or whatever cutting instrument can be best applied; but this will vary, according to their situations and the extent of their base. They will often rise in a day or two after tha operation as high as ever; but this newly generated matter generally dies soon, and the disease terminates well. They have often so much of a cancerous appearance as to deter surgeons from meddling with them ; but where they arise at once from the gum, and appear to be the only diseased part, I believe they have no malignant disposition. However, I have seen them with very broad bases, and where the whole could not be removed, and yet no bad consequences have attended their removal. These often rise again in a few years, by which means they become very troublesome. After the extirpation of them, it is often necessary to apply the actual cautery to stop the bleeding; for arteries going to increased

* [The practical surgeon who has seen much of the diseases of the teeth will see that the long detail of the treatment of gum-boil, or, as it may with more propriety be termed, alveolar abscess, is altogether supererogatory. The roots occasioning these gum-boils must be removed, or every other means will fail.] 76 HUNTER ON THE TEETH. parts are themselves increased, and also become diseased, and have not the contractile power of a sound artery.*

§ 6. Deeply seated Abscesses in the Jaws.

Sometimes deeper abscesses occur than those commonly called gum-boils. They are often of very serious consequence, producing carious bones, &c. These commonly arise from a disease in the tooth, and more especially in the cuspidati, those teeth passing further into the jaw than the others. Their depth in the jaw being beyond the attachment of the lip to the gum, if an abscess forms at their points, it more readily makes its way through the common integuments of the face, than between the gum and lip, which disfigures the face ; and when in the lower jaw looks like the evil. In the upper jaw it makes a disagreeable scar on the face, about half an inch from the nose. These, although they may sometimes arise from diseases of the teeth and gums, yet are properly the object of common surgery; and the surgeon must apply to the dentist, if his assistance is necessary, to pull out the tooth, or to perform any other operation which comes under his province. It sometimes happens that the abscess is situated some way from the root of the diseased tooth both in the upper jaw and the lower; but, I think, more frequently in the lower. When it threatens to open externally on the skin of the face, great care should be taken to prevent it, and an opening very early made into the swelling on the inside of the lip; for it is generally very readily felt there. This practice of early opening these abscesses on the inside of the mouth is more necessary when the abscess is in the lower jaw than when m the upper, because matter by its weight always produces ulceration more readily at the lower part. I have seen this practice answer, even when the matter had come so near the skin as to have inflamed it. If it is in the upper, the opening need not be so very large, as the matter will have a depending outlet. To prevent a relapse of the disease, it will in most cases be necessary to pull out the tooth; which has either been the first cause, or has become diseased, in consequence of the formation of the abscess; and in either case is capable of reproducing the disease. Ihe mouth should be often washed ; and while the water is within the mouth the skin should be pressed opposite to the abscess. DrobabTv wntti6 ? ^ destr°>'ed' il will exfoliate ; and very probably two or three of the teeth may come away with the exfo- * [Whenever the tumours here described arD r^-i ji , . . from diseased or dead teeth, the^- wSl constanS^^ ^ *e Irritotion ar "I* cause is removed by the extraction of theteeth -JT-1 a/ter [emoval> «ntl1 the this operation they disappear spontaneously It' if " en haPPens l"at after of this description so completely to conceal' thP f unf>-°mmon for a tumour growth, that it is only by the excision of the t P u has occasi<>ned its ascertained. It is therefore necessary in all o« ?aJ. that the cause can be should be carefully searched for after the rem » f V , descriPtion that a root removal of such a tumour.] ABSCESS OF THE ANTRUM MAXILLARE. 77 liation. Little should be done in such cases, except that the patient should keep the mouth as clean as possible by frequently washing it, and when the bones exfoliate, they should be removed as soon as possible. In these cases it is but too common for the dentist to be very busy, and perhaps do mischief through ignorance.

§ 7. Abscess of the Antrum Maxillare.

The antrum maxillare is very subject to inflammation and suppuration, in consequence of diseases of the neighbouring parts, and particularly of the duct leading to the nose being obliterated. Whether this is the cause, or only an effect, is not easily determined, but there is great reason to suppose it an attendant, from some of the symptoms. If it be a cause, we may suppose that the natural mucus of these cavities accumulating irritates and produces inflammation for its own exit, in the same manner as an obstruction to the passage of the tears through the lachrymal duct produces an abscess of the lachrymal sac. This inflammation of the antrum gives a pain which will be at first taken for the tooth-ache, especially if there be a bad tooth in that side; however, in these cases, the nose is more affected than commonly in a tooth-ache. The eye is also affected; and it is very common for people with such a disease to have a severe pain in the forehead, where the frontal sinuses are placed ; but still the symptoms are not sufficient to distinguish the disease. Time must disclose the true cause of the pain ; for it will commonly continue longer than that which arises from a diseased tooth, and will become more and more severe; after which a redness will be observed on the fore part of the cheek, somewhat higher than the roots of the teeth, and a hardness in the same place, which will be considerably circumscribed. This hardness may be felt rather highly situated on the inside of the lip. As this disease has been often treated of by surgeons, I shall only make the following remarks concerning it. The first part of the cure, as well as of that of all other abscesses, is to make an opening, but not in the part where it threatens to point: for that would generally be through the skin of the cheek. If the disease is known early, before it has caused the destruction of the fore part of the bone, there are two ways of opening the abscess: one by perforating the partition between the antrim and the nose, which may be done ; and the other by drawing the first or second grinder of that side, and perforating the partition between the root of the alveolar process and the antrum, so that the matter may be discharged for the future that way. But if the fore part of the bone has been destroyed, an opening may be made on the inside of the lip, where the abscess most probably will be felt; but this will be more apt than the other perforation to heal, and thereby may occasion a new accumulation; which 78 HUNTER ON THE TEETH. is to be avoided, if possible, by putting in practice all the common methods of preventing openings from healing or closing up : but this practice will rather prove troublesome; therefore the drawing the tooth is to be preferred, because it is not so liable to this objection.* CHAPTER II.

OF THE DISEASES OF THE ALVEOLAR PROCESSES, AND THE CONSE- QUENCES OF THEM.

Having thus far treated of the diseases of the teeth themselves, and those of the sockets and gums, which either arise from them or are similar to such as arise from them, I come now to consider the diseases which take place primarily in the sockets, when the teeth are perfectly sound. These appear to be two; and yet I am not sure but that they are both fundamentally the same, proceeding together from the same cause, or one depending on the other. The first effect which takes place is a wasting of the alveolar processes, which are in many people gradually absorbed and taken into the system. This wasting begins first at the edge of the socket, and gradually goes on to the root or bottom. The gum, which is supported by the alveolar process, loses its connexion, and recedes from the body of the tooth, in proportion as the socket is lost; in consequence of which, first the neck, and then more or less of the fang itself, becomes exposed. The tooth of course becomes extremely loose, and at last drops out. The other effect is a filling up of the socket at the bottom, whereby the tooth is gradually pushed out. As this disease seldom happens without being attended by the other, it is most probable that they generally both arise from the same cause. The second in these cases may be an effect of the first. Both combine to hasten the oss of the tooth; but it sometimes happens that they act separately; for I have seen cases where the gum was leaving the teeth

nehiSV^t "atUFe ° rtMs- affe°tion is generally mistaken, and the error is perfhan an alU^ rafaPPhcatIf0" of the te™ "bscess. It consists of nothing more co^on^™^l^Cus ^Z ^^^Uy, gonorrhoea. It does not always hannen thlt th! • ^"^ ,°f the Urethra ln impervious in this disease Te even where thisTo"^ "^ ?° D08e ^T6" and allows of a ready exit for thlZZpunl^^Zf^^^1"^ applied to the diseased membrane withou,^remoVf„ra?n't^f'Tvf6168 CM H perforating the floor of the antrum. ThT usua?S °7 ^ f°r,the PurP0Se °f of a small trocar; and the treatment b simUa^t0 thl^r^ *» " by r*"' relates to the injection of stimulant or astrin^nf 1? • ?onorrh°ea, as far as course liable to the same objections in the m-Slf ?P loatlons' whi°h are not of mentioned.] J e present instance as in the disease just DISEASES OF THE ALVEOLAR PROCESSES. 79

and yet the tooth was not in the least protruded; on the other hand, I have seen cases where the tooth was protruding, and yet the gum kept its breadth; but where this is not the case, and the gums generally become extremely diseased; and as they are separated from both the teeth and the alveolar process, there is a very considerable discharge of matter from those detached surfaces. Though the wasting of the alveoli at their mouths, and the filling up at their bottoms, are to be considered as diseases, when they happen early in life, yet it would appear to be only on account of a natural effect taking place too soon; for the same thing is very common in old age ;* and also, as this process of filling up the bottom, and wasting of the mouths of the alveolar processes, takes place in all ages, where a tooth has been drawn, and the connexion between the two parts is destroyed, this might lead us to suspect that the original cause of these diseases may be a want of that perfect harmony which is required between the tooth and socket, whereby a stimulus may be given in some degree similar to the loss of a tooth; and by destroying that stimulus upon which the absorption of the process and the filling up of the socket depend, the natural disposition may be restored. This last opinion is strengthened by the following case. One of the first incisores of the upper jaw of a young lady was gradually falling lower and lower. She was desirous of having a tooth transplanted, which might better fit the shallow socket, as it was now become. She consulted me: I objected to this, fearing that the same disposition might still continue; in which case the new tooth would be probably pushed out in about half a year; that the time since the old one began to sink, and a relief of so short a continuance, would be all the advantage gained by the operation; but I observed, at the same time, that the operation might have the effect of destroying the disposition to filling up, so that the new tooth might keep its ground. This idea turned the balance in favour of the operation ; and it was performed. Time showed that the reasoning was just; the tooth fastened, and has kept in its situation for some years. These diseases arise often from visible causes. Anything that occasions a considerable and long-continued inflammation in those parts, such particularly as salivation, will produce the same effect. The scurvy, also, when carried to a great height, attacks the gums and the alveolar processes, which becomes a cause of the dissolution of those parts. This is most remarkable in the scurvy at sea. When the disease arises from these two last causes, the gums are either effected with the same disease, together with the alveolar processes, or they sympathize with them. They swell, become soft and tender, and upon the least pressure or friction bleed very freely. How far these diseases can be prevented and cured is, I believe, not known. ♦ Natural History of the Teeth, p. 11. 80 HUNTER ON THE TEETH. The practice has principally been to scarify the gums freely; and this with a view to fasten the teeth made loose by the disease, which has therefore generally made a considerable progress before even an attempt towards a cure has been made. This scarification has certainly a good effect in some cases, the teeth thereby becoming much faster; but how far the alveolar processes have been destroyed in such instances cannot be determined. Perhaps only a general fulness of the attaching membrane between the tooth and the process had taken place, as in a slight salivation, so as to push the tooth a little way out of the bony socket; which having subsided by the plentiful bleeding, the tooth of course becomes fast. Or perhaps, by producing an inflammation of another kind, the first inflammation, or disposition to inflame, is destroyed; which evidently appeared in the case of the young lady above mentioned. If the above practice is unsuccessful, and the tooth continues to protrude, it will either become very troublesome or a great deformity. A front tooth may not, indeed, be at first so troublesome as a grinder, because these teeth frequently overhang, but it will be extremely disagreeable to the eye. If the cause cannot be removed, the effect must be the object of our attention. To file down the projecting part is the only thing that can be done; but care must be taken not to file into the cavity, otherwise pain, inflammation, and other bad consequences may probably ensue. This practice, however, will be very troublesome, because it will be difficult to file a loose tooth. At last the tooth will drop out, which will put an end to all further trouble. If the alveoli have really been destroyed in those cases of loose teeth which have become firm again, it would be difficult to ascertain whether they have a power of renewing themselves analogous to that power by which they first grow, or whether the fastening be effected by a closing of the gum and process to the teeth. When the disease arises from the scurvy, the first attempt must be to cure that disease, and afterwards the above local treatment may be of service. Together with drawing blood from the gums, astringents have always been used to harden them. But when the disease does not arise from a constitutional cause, which may be removed (such as the sea-scurvy or salivation), but from a disposition in the parts themselves, I have seen little relief given by them. The tincture of myrrh, tincture of Peruvian bark, and sea-water are some of the applications which have been recommended. In such cases I have seen considerable benefit from the use of the tincture of bark and laudanum, in the proportion of two parts of the tincture of bark to one of the laudanum: and this to be used frequently, and at each time to be kept in the mouth durino- ten, fifteen, or twenty minutes.* °

* [The practice here recommended of filing a tooth which is descending in the alveolus, is, on more than one account, exceedingly injurious. The immediate DISEASES OF THE GUMS, ETC. 81 CHAPTER III.

OF THE DISEASES OF THE GUMS, AND THE CONSEQUENCES OF THEM.

§ 1. The Scurvy in the Gums {vulgarly so called). The gums are extremely subject to diseases, the symptoms of which, in an advanced state of them, are in general such as were described in the preceding chapter. They swell, become extremely tender, and bleed upon every occasion; which circumstances being somewhat similar to those observable in the true scurvy, the disease has generally been called a scurvy in the gums. But as this seems to be the principal way in which the gums are affected, I suspect that the same symptoms may arise from various causes, as I have often seen the same appearances in children evidently of a scrofulous habit, and have also suspected the same cause in grown people; they likewise frequently appear in persons who are in all other respects perfectly healthy. When the gums first begin to have a tenderness, we may observe it first on their edges; the common smooth skin of the gum is not continued to its very edge, but becomes at the edge a little rough like a border, and somewhat thickened. The part of the gum between two teeth swells, and often pushes out like luxuriant flesh, which is frequently very tender. The inflammation is often carried so far as to make the gums ulcerate, so that the gums in many cases have a common ulcer upon them, by which process a part of the teeth is denuded. This is often on one part only, often only on one jaw, while in some cases it is on the whole gums on both jaws. In this case it often happens that the alveolar process disappears, after the manner above described (see page 80), by taking part in the inflammation, either from the same cause, or from sympathy. In such cases there is always a very considerable discharge of matter from the inside of the gum and alveolar process, which always takes the course of the tooth for its exit. cause of such a descent of the tooth is, as Hunter observes, a deposit of bone in the alveolus; and, as this deposit takes place in consequence of some irritation in the periosteum, everything should be avoided that could increase this irritation. Filing, however, would certainly increase it to a great degree. It would also tend greatly to lessen the attachment of the tooth to the socket, and the support which the latter affords to it. The best mode of treatment appears to be, to apply leeches occasionally, particularly when there is any unusual sensation produced by touching the tooth, indicating a degree of inflammation in the periosteum of the socket. This plan may be followed up by the use of astringent lotions. It is unnecessary to add, that any force applied to the tooth, and even frequently touching it, should be avoided. Ligatures are especially improper.] 9 Si HUNTER ON THE TEETH. In many of these cases we find that while the gums are ulcerating in one part, they are swelling and becoming spongy in another, and hanging loose upon the teeth; and this often takes place where there is no ulceration in any part. The treatment proper in this disease, where the gums become luxuriant from a kind of tumefaction, is generally to cut away all the redundant swellings of the gum. I have seen several instances where this has succeeded; but still I am inclined to think that this is not the best practice; for it is not that an adventitious substance is thus removed, as in the case of luxuriant granulations from a sore, but a part of the gum itself is destroyed, in like manner as a part enlarged by inflammation may be reduced by the knife to its natural size; which would certainly be bad practice. I should suspect that the good arising from such practice is owing to the bleeding which takes place, especially as I have found from experience that simply scarifying the gums has answered the same purpose. Where there are reasons for supposing it to arise from a peculiarity in the constitution, the treatment should be such as will remove this peculiarity. ' If the constitution is scorbutic, it must be treated with a view to the original d.sease. If scrofulous, local treatment, by wounding the parts, may do harm; but sea-bathing, and washing the mouth thTfknow * SGa'Water' are the most Powerful means of cure

§ 2. Callous Thickenings of the Gums.

co^x?orvvirthaiSnlSUb-ieCt 'a °thT difases' abst™cted from their ^pros^ect ^ ' "MCh d° "^ Wb°lly bd0ngt°

ticirice^T uTa " ^ thickcnin2 of the Sum » »me par- Many ofthe'se hLo a CaH°US n&tUre' similar to an excrescence. surcr/oEif^m^' cancerous appearance, which deters the They mav be oftPnng '^ ^mjubut in Seneral ^out ™son. bleeding Xn fnH ^^ V6 knife' but not aIwavs- The

sal oVertioresi8hrr ¥ain' wh,ich ■«the ?*«"* *> ** such caLs I SUSpcct thai ttT" l^T GXtraCted six times' but in suspect that they really have a cancerous disposition;

noUc^oft ^^e^L^^J^^ ever come underthe benefit, the two remedies J^ZSZii^]^^UWZf^mmmt mouth with sea-water, have proved asH,, t ' .. ba,hln? and washin? *<> means of cure. It is very probable that the 1^"" ?hseTves' ^ most powerful and of scene, and the absence of all the defbfiT^ t0m,C effeCt °fchan£e of air tion to business and of a town resi,fence aid e*?**™** of close applies* sisted the means alluded to; bu there anni,hablts' ma7 have greatly asbenefit derived from the local kpp" caS 0/ Sea ^ 8°] t0 ^ ^ mUch *rect NERVOUS PAINS IN THE JAWS. 83

at least, it has been so in two cases which have fallen under my observation. But here the skill of the surgeon rather than that of the dentist is required. CHAPTER IV.

OF NERVOUS PAINS IN THE JAWS.

There is one disease of the jaws which seems in reality to have no connexion with the teeth, but of which the teeth are generally suspected to be the cause. This deserves to be taken notice of in this place because operators have frequently been deceived by it, and even sound teeth have sometimes been extracted through an unfortunate mistake. This pain is seated in some one part of the jaws. As simple pain demonstrates nothing, a tooth is often suspected, and is perhaps drawn out; but still the pain continues, with this difference, however, that it now seems to be in the root of the next tooth; it is then supposed either by the patient or the operator that the wrong tooth was extracted, whereupon that in which the pain now seems to be is drawn, but with as little benefit. I have known cases of this kind where all the teeth of the affected side of the jaw have been drawn out, and the pain has continued in the jaw; in others it has had a different effect, the sensation of pain has become more diffused, and has at last attacked the corresponding side of the tongue. In the first case I have known it recommended to cut down upon the jaw, and even to perforate and cauterize it, but all without effect. Hence it should appear that the pain in question does not arise from any disease in the part, but is entirely a nervous affection. It is sometimes brought on, or increased, by affections of the mind, of which I once saw a remarkable instance in a young lady. It often has its periods, and these are frequently very regular. The regularity of its periods gives an idea of its being a proper case for the bark, which however frequently fails. I have, seen cases of some years' standing, where the hemlock ' has succeeded when'the bark has had no effect; but sometimes all attempts prove unsuccessful. Sea-bathing has been in some cases of singular service.* * [The disease here treated of is evidently that which has since the time of Hunter been so often treated of under the terms Neuralgia and Tic-douloureux. It is unnecessary here to say much on the subject of this disease when arising from constitutional causes, in which case, I believe, the periodical character will almost always distinguish it; but it may not be useless to offer a few observations on those cases of local neuralgia which are more or less connected with the teeth, and which more or less nearly stimulate tic-douloureux, especially when occurring in a constitution predisposed to that affection. It appears that the pres- 84 HUNTER ON THE TEETH. CHAPTER V.

OF THE EXTRANEOUS MATTER UPON THE TEETH.

There are parts of the tooth which lie out of the way of friction, viz. the angles made by two teeth, and the small indentation between the tooth and gum. Into these places the juices are pressed, and there stagnate, giving them at first the appearance of being stained or dirty. A tooth in this stage is generally clean for some way from its cutting edge towards the gum, on account of the motion of the lips upon it, and the pressure of the food, &c. It is also pretty clean close to the gum from the motion of the loose edge of the gum upon that partbut this circumstance is only observable in those who have their gums perfectly sound, for in others this loose edge of the o-um is either lost, or no longer retains its free motion. If art be not now used, as the natural motion of the parts is not sufficient, the incrustation increasing covers more and more of the teeth. As mastication generally keeps that part clear which is near to the edges and grinding surfaces, and as the motion of the lips in some measure retards its growth outwards, it accumulates on the parts above mentioned till it rises almost as high as the gum; its

fdT nP,T? ^ retard6d hi!that direction' h accumulate* on the I f?\ ! e gUm' S0 that in time * Passes over the gum, of which it covers a greater or less portion. When it has incYea ed so much as to touch the gum (which very soon happens especiallv

lltauin ofebIden thGteelh)' ^ P^°duC"S "IceraSTof th^ and a train of bad consequences. Often the gums receding from this matter, become very tender and subject tffioSa«^

ulcl?ate s'ta't ZT7 *"*??*' ?k° parl with the Z"™> *** u cerate so that the teeth are left without their support ?nd at last

Vw^L% thG diS6aS!S °f„these Parts aEy descr e which's dis olvediTZ" COns!dei^b[e ^antity of calcareous earth, wnicn is dissolved in them, and which is separated from them upon

TqVestiorlS on the extremhy of the Mt^lf^S? *Ppe?a ^ the dePosit ofbony ™tter other similar caLe will produce i.|ooththe existence of a dead tooth, and any tional remedy, usually employed in ti/Znlfen * °f Vn which every constitueffect for an affectio/of this; & which had" 'he? ^ been emPloyed without attacks; and on learning that it had exisfprl t bec?me excessively violent in its the part was carefully examined, anVa .*.nZZXZt* T"f °D °f * t0°th' discovered under the edge of the ffum on 1 k ?f the alve»lar process was was instantly excited. The removal of this sS^ ** ^^ °f Pain This case is here mentioned to show how triflin Was at once successful. severe pains of this description, and to point «„? .? °aUSe may P'oducatbe most even minute examination of the nart in which thl • necessity f°r a careful and 1 which the pain appears to commence.] EXTRANEOUS MATTER UPON THE TEETH. 85

exposure, which continues mixed with the mucus; so that the extraneous matter consists of earth and the common secreted mucus.* This disposition of the juices of the mouth to abound so much with earth, seems to be peculiar to some people, perhaps to some constitutions; but I have not been able to ascertain what these are. We find persons who seem to have nothing particular either in constitution or way of life so subject to this accumulation that the common methods of prevention, such as washing and brushing the teeth, have not the desired effect. The disposition is so strong in some people that the concretion forms on the whole body of the tooth; I have seen it even on the grinding surface of the molares, and often two or three teeth are cemented together with it. This I think could only happen to those who seldom or never use these teeth. It is very apt to accumulate on a tooth the opposite of which is lost. I once saw a case of this kind where the accumulation, which was on a grinder, appeared like a tumour on the inside of the mouth, and made a rising in the cheek, which was supposed by every one that felt it to be a scirrhous tumour forming on the cheek; but it broke off and discovered what it was. This accumulation is very apt to begin during a fit of sickness, when the extraneous juices are allowed to rest; and perhaps the juices themselves may have at this time a greater tendency to produce the incrusting matter. It may also arise from any circumstance which prevents a person from eating solids, whereby the different parts of the mouth have less motion on each other. Lying-in women are instances of this; not to mention that the assistance of art in keeping the teeth clean is commonly wanting under such circumstances. The adventitious substance, as was said before, is composed of mucus, or animal juices, and calcareous earth ; the earth is attached to and crystallized upon the tooth, and the mucus is entangled in these crystals. The removal of this adventitious matter is a part in which the dentist ought to be very cautious; he should be perfectly master of the difference between the natural, or original, tooth and the adventitious matter ; and he should be sensible of the propriety of saving as much as possible of the tooth, and at the same time take pains to remove all that which is not natural. Many persons have had their teeth wholly spoiled by an injudicious treatment of them in this respect. As the cause of this incrustation is not either a known disease of the constitution or of the parts, but depends on a property of the matter secreted, simply as inanimate matter, the remedy of course becomes either mechanical or chemical. The mechanical remedies are friction, filing, and picking. The

'■'- Vide Natural History, page 57, in the note, for a further description of this. 9* 86 HUNTER ON THE TEETH. first is sufficient when the teeth are only beginning to be discoloured ; or, when already clean, they may be thus kept clean. Various are the methods proposed : to wash them with cold water, and at the same time to rub them with a piece of cloth on the fore finger, has been thought sufficient by some; others have recommended the dust of a burnt cork, burnt bread, &c, with a view to act with more power on the adventitious matter than what can be applied by the means of a soft brush or cloth. In cases where this incrustation has been more considerable, powders of various kinds have been employed, such as tartar, bole, and many others. Cream of tartar is often used, which at the same time that it acts mechanically, has likewise a chemical power, and dissolves this matter. Other mechanical means are instruments to pick, scrape, and file off the calcareous earth ; these should only be made use of when it is in large quantities, and with great caution, as the teeth may be somewhat loose ; or a part of the tooth may be broken off with the incrustation. The chemical means are solvents: these are either alkalies or acids; the alkaline salt will answer very well early in the disease, for the crust in the first stage consists chiefly of mucus, which the alkali will remove very readily; but it should not be used too freely, as it rather softens the gums, and makes them extremely tender. Acids are also employed with success, as they dissolve the earth, but are attended with this disadvantage, that they act with more force upon the tooth itself, dissolving part of it; which is to be avoided, if possible, for no part of a sound tooth can be spared. We may observe that people who eat a good deal of salad or fruit have their teeth much cleaner than common, which is owing to the acids in those fruits; and for the same reason people's teeth are commonly cleaner in summer than winter in those countries where there is a great plenty of fruit. When the accumulation has been considerable, the teeth and gums will feel tender on the removal ot this matter, and even be affected by cold air ; but this will not be of long continuance. CHAPTER VI.

OF THE IRREGULARITY OF THE TEETH.

of AtVh^■ °f Th jaW Whlch holds the ten fore teeth is exactly of the same size when it contains those of the first set as when it contains those of the second, and as these last often occudv a much arger space than the first,* in such cases the second" etTre obTed to stand very irregularly. ouugea

* Natural History, p. 48. IRREGULARITY" OF THE TEETH- 87 This happens much oftener in the upper jaw than in the lower, because the difference of the size of the two sets is much greater in that jaw. This irregularity is observed almost solely in the incisores and cuspidati; for they are the only teeth which are larger than their predecessors. It most frequently happens to the cuspidati, because they are often formed later than the bicuspides; in consequence of which the whole space is taken up before they make their appearance : in such cases they are obliged to shoot forwards or outwards over the second incisor. However, it frequently happens to the incisores, but seldom to such a degree. This arises often from the temporary cuspidatus of one or both sides standing firm. I have seen the irregularities so much as to appear like a double row. The bicuspides generally have sufficient room to grow, because even more space than what they can occupy is kept for them by the temporary grinders.* This, however, is not universally the case; for I have seen where the bicuspides were obliged to grow out of the circle, very probably from their being later in growing than common. That it is from want of room in the jaw, and not from any effect that the first set produces upon them, is evident; first, because in all cases of irregularity we find that there is really not room in the jaw to allow of placing all the teeth properly in the circle; so that some are necessarily on the outside of the circle, others within it, while others are turned with their edges obliquely, as it were warped; and secondly, because the bicuspides are not out of the circle, although they are as much influenced by the first set as any of the others. As they are not influenced by the first set, it cannot be of any service to draw the first possessor, for that gives way in the same proportion as the other advances. As the succeeding tooth, however, is broader, it often interferes with a shedding tooth next to it, the fang of which not being influenced by the growth of its own succeeding tooth, it does not decay in proportion as the other advances, and therefore the drawing of the adjoining shedding tooth is often of service.f In cases of considerable irregularity for want of room, a principal object is to remove those which are most out of their place, and thereby procure room for the others which are to be brought into the circle. To extract an irregular tooth would answer but little purpose if no alteration could be made in the situation of the rest; but we find that the very principle upon which teeth are made to grow irregularly is capable, if properly directed, of bringing them even again. This principle is the power which many parts (especially bones) have of moving out of the way of mechanical pressure. * Natural History, p. 40. f Ibid., p. 50. 88 HUNTER ON THE TEETH. The irregularitv of the teeth is at first owing to mechanical pressure ; for one tooth getting the start of another, and fixing firmly in its place, becomes a. resistance to the young, loose, forming tooth, and gives it an oblique direction. The same principle takes place in a completely formed tooth whenever a pressure is made upon it. Probably a tooth might by slow degrees be moved to any part of the mouth, for I have seen the cuspidati pressed into the place of the incisores. However, it is observed that the teeth are easier moved backwards than forwards, and when moved back that they are permanent, but often when moved forwards that they are very apt to recede. The best time for moving the teeth is in youth, while the jaws have an adapting disposition; for after a certain time they do not so readily suit themselves to the irregularity of the teeth. This we see plainly to be the case when we compare the loss of a tooth at the age of fifteen years and at that of thirty or forty. In the first case we find that the two neighbouring teeth approach on another, in every part alike, till they are close ; but in the second the distance in the jaw between the two neighbouring teeth remains the same, while the bodies will in a small degree incline to one another from want of lateral support. And this circumstance of the bodies of the teeth yielding to pressure upon their base, shows that even in the adult they might be brought nearer to one another by art properly applied. As the operation of moving the teeth is by lateral pressure upon their bodies, these bodies must first have passed through the gum sufficiently for a hold to be taken. The best time seems to be, when the two grinders of the child have been shed ; for at this time a natural alteration is taking place in that part of the jaw. The means of making this pressure I shall only slightly describe, as they will greatly vary according to circumstances, so considerably, indeed, that scarcely two cases are to be treated alike, and in general the dentists are tolerablv well acquainted with the methods. In general, it is done with ligatures or plates of silver. The ligatures answer best when it is only required to bring two teeth closer together, which are pretty much in the circle. The trouble attending this is but trifling, as it is only that of having them tied once a week or fortnight. Where teeth growing out of the circle are to be brought into it, curved silver plates, of a proper construction, must be used. These are generally made to act on three points, two fixed points on the standing teeth and the third on the tooth which is to be moved. That part of the plate which rests on the two standing teeth must be of a sufficient length for that purpose, while the curved part is short and goes on the opposite side of the tooth to be moved. Its effect depends very much on the attention of the patient, who must frequently press hard upon it with the teeth of the opposite jaw so IRREGULARITY OF THE TEETH. 89 that this method is much more troublesome to the patient than the ligature. It is impossible to give absolute directions what tooth or teeth ought to be pulled out. That must be left to the judgment of the operator; but the following general- hints may be of service. I. If there is any one tooth very much out of the row, and all the others regular, that tooth may be removed, and the two neighbouring ones brought closer together. 2. If there are two or more teeth of the same side very irregular (as, for instance, the second incisor and cuspidatus), and it appears to be of no consequence, with respect to regularity, which of them is removed, I should recommend the extraction of the furthest back of the two, viz. the cuspidatus; because, if there should be any space not filled up when the other is brought into the row, it will not be so readily seen. 3. If the above-mentioned two teeth are not in the circle, but still not far out of it, and yet there is not room for both, in such a case, I would recommend the extraction of the first bicuspis, although it should be perfectly in the row, because the two others will then be easily brought into the circle, and if there is any space left, it will be so far back as not to be at all observable. The upper jaw is often rather too narrow from side to side, near the anterior part which supports the fore teeth, and projects forwards considerably over the lower, giving the appearance of the rabbit-mouth, although the teeth be quite regular in the circle of the jaw. In such a case it is necessary to draw a bicuspis of each side, by which means the fore part of the circle will fall back ; and if a cross-bar was to be stretched from side to side across the roof of the mouth, between cuspis and cuspis, it would widen the circle. The fore teeth might also be tied to this bar, which would be a means of assisting nature in bringing them back. This has been practised, but it is troublesome. As neither the bodies nor the fangs of the teeth are perfectly round, we find that this circumstance often becomes a cause of their taking a twist; for, while growing, they may press with one edge only on the completely formed tooth, by which means they will be turned a little upon their centre. The alteration of these is more difficult than of the former, for it is, in general, impossible to apply, so long and constantly as is necessary for such an operation, any pressure that has the power of turning the tooth upon its centre. However, in the incisores, it may be done by the same powers which produce the lateral motion; but where these cannot be applied, as is frequently the case, the tooth may be either pulled out entirely, and put in again even, or it may be twristed round sufficiently to bring it into a proper position, as has been often practised. It may not be improper, in this place, to take notice of a case which frequently occurs. It is a decay of the first adult grinder at 90 HUNTER ON THE TEETH. an early age, viz. before the temporary grinders are shed, and before the second grinder of the adult has made its appearance through the gum. In this case, I would recommend removing the diseased tooth immediately, although it may occasion no kind of trouble; for, if it be drawn'before the temporary grinders are shed, and before the second adult grinder has cut the gum, it will in a short time not be missed; because the bicuspis of that side will fall a little back, and the second and third grinders will come a little forward, by which means the space will be filled up, and these teeth will be well supported. Besides, the removal of this tooth will make room for the fore teeth, which are often very much wanted, especially in the upper jaw.* CHArTER VII.

OF IRREGULARITIES BETWEEN THE TEETH AND JAWS.

Certain disproportions between the teeth and jaw sometimes occur, oneof which is, when the body of the lower jaw is not of sufficient length for all the teeth. In such cases, the last grinder never gets perfectly from under the coronoid process, its anterior edge only being uncovered; and the gum, which still in part lies upon the tooth, is rubbed against the sharp points of the tooth, and is often squeezed between the tooth upon which it lies and the corresponding one of the upper jaw. This occasions so much uneasiness to the patient, that it becomes necessary to relieve the gum, if possible, by dividing it freely in several places, that it may shrink and leave this surface of the tooth wholly uncovered. If this does not answer, which is sometimes the case, it is advisable to draw the tooth. Sometimes, although but seldom, an inconvenience arises from the dentes sapientiae being in the upper jaw and not in the lower; these teeth pressing upon the anterior part of the root of the coronoid process when the mouth is shut; for the coronoid processes are * [The foregoing observations on irregularity are generally very judicious; and it would have been well if many writers on this subject had imitated the moderation which characterizes the mode of treatment here recommended. It is in the treatment of the teeth of children during the second dentition that we have in the present day chiefly to deplore the continual interference of interested ignorance, in the early removal of the temporary teeth, under the pretence of making room fox the permanent ones. It is impossible too often or too forcibly to deprecate this practice. Cruel as it is, this is perhaps its least evil, for the pain and apprehension which are occasioned by it are but temporary ; but a great permaimnvpTh ? T .S FaCt,0e' WtliQh is' that if the temporary teeth be removed before the permanent ones are ready to fall into their place, the iaw will considerably contract during the growth of the child, and thus create ad iSce pancy between the size of the new teeth and the extent of the arch whfch they occupy. I feel assured that upon the whole, more injury is at present done! with regard to irregularity, by the interference of dentists, than wonM accrue were the teeth of children at this period never examined or meddled with aJal THE UNDER JAW. 91 further forwards in such cases than when the lower jaw also has its dentes sapientias; in short, the exact correspondence between the two jaws is not kept up. In such cases, I know of no other remedy but the extraction of the tooth. Of Supernumerary Teeth. When there are supernumerary teeth,* it will in general be proper to have them drawn, for they are commonly either troublesome, or disfigure the mouth. CHAPTER VITI.

It is not uncommon to find the lower jaw projecting too far forwards, so that its fore teeth pass before those of the upper jaw when the mouth is shut ;f which is attended with inconvenience, and disfigures the face. This deformity can be greatly mended in young people. The teeth in the lower jaw can be gradually pushed back, in those whose teeth are not close, while those in the upper can be gently brought forward ; which is by much the easiest operation. These two effects are produced by the same mechanical powers. While this position of the jaw is only in a small degree, so that the edges of the under teeth can be by the patient brought behind those of the upper, it is in his own power to increase this till the whole be completed, that is, till the grinders meet; and it is not necessary to go further. This is done by frequently bringing the lower jaw as far back as he can, and then squeezing the teeth as close together as possible. But when it is not in the person's power to bring the lower jaw so far back as to allow the edges of its fore teeth to come behind those of the upper, artificial means are necessary. The best of these means is an instrument of silver, with a socket or groove shaped to the fore teeth of the lower jaw to receive them, so as to become fast to them, and sloped off as it rises to its upper edge, so as to rise behind the fore teeth in the upper jaw in such a manner that, upon shutting the mouth, the teeth of the upper jaw may catch the anterior part of the slanting surface, and be pushed forward with the power of the inclined plane. The patient who wears such an instrument must frequently shut his mouth with this view. These need not be continued longer than till the edges of the lower teeth can be got behind those of the upper, for it is then within the power of the patient, as in the first-slated case. * Natural History, p. 49. t Ibid. p. 35. 92 HUNTER ON THE TEETH. CHAPTER IX.

The extraction of teeth is. in some cases an operation of considerable delicacy, and in others no operation is less difficult. As this is often not thought of till an inflammation has come on, it becomes an object of consideration whether it be proper to remove the tooth while that inflammation continues, or to wait till it has subsided. I am apt to believe it is better to wait even till the parts have perfectly recovered themselves, because the state of irritation renders them more susceptible of pain. The contrary practice might also appear reasonable, for by removing the tooth it might be imagined that we should remove the cause; but when the inflammation has once begun, the effect will go on independently of the cause; and to draw the tooth, in such a situation, is rather to produce a fresh cause, than to remove the present. Of this I think an instance has occurred to me. However, most teeth are drawn in the height of inflammation; and, as we do not find any mischief from the operation, it is perhaps better to do it when the resolution of the patient is the greatest. The sensibility of the mind may even be less at this time. Teeth are easy or difficult of extraction, according as they are fast or loose in their sockets; in some degree according to the kind of tooth, and also in some degree with reference to their situation.* They are naturally so fast as to require instruments, and the most cautious and dextrous hand ; and yet are sometimes loose enough to be pulled out by the fingers. When the sockets and gums are considerably decayed, and the tooth or teeth very loose, it would in most cases be right to perform extraction; for when they are allowed to stay, and perhaps are kept in their proper place by being tied to the neighbouring teeth, then they act upon the remaining gum and socket as extraneous bodies, producing ulceration there, and making those parts recede much further than they naturally would have done if the tooth had been drawn earlier ; which produces two bad effects—it weakens the lateral support of the two neighbouring teeth, and it renders it more difficult to fix an artificial tooth. But unless these two last circumstances are forcibly impressed upon the patient, it is hardly possible to persuade him to consent to the loss of a tooth while it has any hold, especially a tooth which appears sound. The extraction should never be done quickly ; for this often occa-

*For further directions, see Natural History, p. 56. DRAWING THE TEETH. 93 sions great mischief, breaking the tooth or jaw; on the same principle as a bullet going against an open door with great velocity will pass through it, but with little velocity will shut it. This caution is most necessary in adults, or in the permanent teeth ;* for in young subjects, where there are only the temporary teeth,f the jaw not being so firm, the tooth is not in much danger of being broken.J It is a common practice to divide the gum from the tooth before it is drawn, which is attended with very little advantage, because at best it can only be imperfectly done, and that part of the gum which adheres to the tooth decays when it is lost. But if such a separation as can be made saves any pain in the whole of the operation, I should certainly recommend it; and at least, in some cases, it might prevent the gum from being torn. It is also a common practice to close the gum, as it is termed; this is more for show than use; for the gum cannot be made so close as to unite by the first intention, and therefore the cavity from which the tooth came must suppurate like every other wound. But, as the sensations of these parts are adapted to such a loss, and as a process very different from that which follows the loss of so much substance in any other part of the body is to take place, the consequent inflammations and suppurations are not so violent.^ We may be allowed to call this a natural operation which goes on in the gum and alveoli, and not a violence; as we see that the delivery of a young animal before its time, which is similar to the drawing of a fixed tooth, in happening before all the containing parts are prepared for the loss, produces considerable local violence, without doing proportionable mischief. Therefore in general it is very unnecessary to do anything at all to the gum. There are some particular circumstances which naturally, and others which accidentally, attend and follow the drawing of teeth; but they are in general of no great consequence. There follows a bleeding from the vessels of the socket and those passing between it and the teeth.|| This commonly is but trifling ; however, instances has occurred where it have been very considerable, and the awkwardness of the situation makes it very difficult to stop it. In general it will be sufficient to stuff the socket with lint, or lint dipped in the oil of turpentine, and to apply a compress of lint, or a piece of cork thicker than the bodies of the adjacent teeth, so that the teeth in the opposite jaw may keep up a pressure. It has been advised, to stuff into the socket some soft wax, on a supposition that it would mould itself to the cavity, and so stop the

* Natural History, p. 40. t Ibid- P1- V- f-16> 17'18- X I must do Mr. Spence the justice to say, that this method appears to be peculiar to him, and that he is the only operator I ever knew who would submit to be instructed, or even allow an equal in knowledge; and I must do the same justice to both his sons. § Vide Natural History, on decay of the alveoli, p. 12. | Natural History, pp. 25, 26, PI. V. f. 1—8. 94 HUNTER ON THE TEETH. bleeding; this perhaps may sometimes answer better than the other method, and therefore should be tried when that fails. It is scarcely possible to draw some teeth without breaking the alveolar processes. This in general is but of little consequence, because, from the nature of the union between the teeth and sockets, these last can scarcely be broken further than the points of the fang, and in very few cases so far; therefore little mischief can ensue, as the fracture extends no further than the part of the socket which will naturally decay after the loss of the tooth ; and that part which does not decay will be filled up as a basis for the gum to rest upon. It has been supposed that the splinters do mischief: I very much doubt this; for if they are not so much detached as to lose the living principle, they still continue part of our body, and are rounded oft at their points, as all splinters are in other fracture* and particularly here, for the reasons already assigned, viz. because the part has a greater disposition for wasting. And if they are wholly detached they will either come awav before the gum contracts entirely or after it is closed will act as an extraneous body, form a small abscess in the gum, and come out. It sometimes happens that the tooth is broken, and its point or more of the fang is left behind, which is very often sufficient to continue the former complaints; and therefore it should be extracted,

wil1 in , ' WUh Carei uIf h Cannot be ext™ct^ the gum will in part grow over it, and the alveoli will decay as far as where it is. The decaying principle of the socket will produce the disoo sition to fill up at the bottom, whereby the stump win b^pushed out; but, perhaps, not till it has given some fits of The tooth-ache

ttToTh-;ctCirCUmStanCe d0CSn0t ^ decerne a° caused

Although this operation is in itself a matter of no difficulty vet

rrVchirWurlea' a'ndTh°f ^ "T,' °f '" °^io^ "ui?e under the ca8erf"hefct^T n°W'edge 'han ^ ,hal comes sary to be observed! espec 1 y in ^.Tvi^h"''..'!0!:'- T transplanted benn p ,n ♦£,♦ • ng tooth wmch 1S t0 be we haVno grbeeaC,avUaS ie^of" hTe" 'l^V* »?""" its '*> a"d the patient- he shn„U „™i cno'te- Much, likewise, depends upon he thinls uicessarv to ffi $&£? S'Vf lhe,de"'ist «« «l» <'™ to he of a proper size &c t u™1"5'' of tee,h ,hat aPPear get out of fis KandTbefore,, ,s "adW^bt ""* n°' b° ™^Z <°

bee^e^'^^rngrf:"?'^" CaD ^ be ^"^ incisores and cuspidati than the' t,W^-,?UCCelSS 1S greater in the quently the ends o-f theWhnK^ff*' ^T !3St having ** the operation will become less perfect circumstance It is hardlv possibie to transpiant the grinders, as the chance of STATE OF THE GUMS AND SOCKETS. 95 fitting the sockets of them is very small. When indeed a grinder is extracted, and the socket sound and perfect, the dentist may, perhaps, be able to fit it by a dead tooth.

Of the State of the Gums and Sockets.

The first object of attention is the sockets and gums of the person who is to have the fresh tooth. If the tooth which is to be removed be not wholly diseased, there is great probability that the socket will be as sound and complete as ever; but if the body of the tooth has been destroyed some time, and the fang has been in the state of what is commonly called a stump, it has most probably begun to decay on its outer surface and point, in which case the socket will be filled up in the same proportion; if so, there is no possibility of success. But as, in the operation of transplanting, the diseased tooth is to be first drawn, it will show the state of the socket; and the scion* tooth is to be left or drawn, according to the appearance on the diseased one. If the appearance be not favourable, and it therefore be not probable that the scion tooth can be introduced, so as to unite in the place of the stump, I would recommend to every dentist to have some dead teeth at hand, that he may have a chance to fit the socket. 1 have known these sometimes last for years, especially when well supported by the neighbouring teeth. Indeed this very practice is recommended by some dentists in preference to the other. But even this should not be attempted unless the socket is sound and pretty large, as the tooth can otherwise have but very little hold. Whenever there are gum-boils I would not recommend transplanting, as there is always in such cases a diseased socket, although the disease has originated in the tooth. In one or two instances, indeed, which I have seen, the boil has been cured by such an operation. If the gums are diseased, and become spongy, as has been described, it will be very improper to transplant, as there will be but little chance of success; also, if the sockets have a disposition to waste, and the tooth becomes in some degree loose; in short, the sockets and gums should be perfectly sound. No person should have a tooth transplanted while taking mercury, even although the gums are not affected by it at the time, for they may become affected by that medicine before the tooth is fixed. I would carry this still further; no one should have a tooth transplanted who has any complaint that may subject him to the taking of mercury before the tooth is well fixed. For this reason, those who have teeth transplanted ought particularly to avoid for some time the

* As the transplanting of teeth is very similar to the ingrafting of trees, I thought that term might be transferred from gardening to surgery, finding no other word so expressive of the thing. 96 HUNTER ON THE TEETH. chance of contracting any complaint for the cure of which mercury may be necessary. I would not recommend transplanting, even where mercury has been taken lately. How soon mercury may be taken after a tooth has been transplanted is not easily ascertained. I have known it fail from this cause (as it seemed) after six weeks, where there was every reason to suppose that it might have been attended with success.

Of the Age of the Person who is to have the Scion Tooth.

The socket should be of its full size, and one or two grinders on each side of each jaw should be full grown, to keep the two jaws at a proper distance, which will allow the transplanted tooth to be undisturbed by the motion of the jaw while fastening. This will be at the age of eighteen or twenty years. It sometimes, however, happens that a fore tooth decays before this age, and even before it is completely formed ; and therefore all the above-mentioned advantages cannot be had. In such cases it is not very material whether transplanting is practised or not as simply to draw the diseased tooth will in most cases be sufficient for the two neighbouring teeth may be brought together, so as to fill up the space, the others following in a less degree, as has been already observed upon irregularities of the teeth.

The scion tooth, or that which is to be transplanted, should be a full-grown young tooth; young, because the principle of life and union is much stronger in such than in old ones. It will be scarcely necessary to observe, that the new teeth should always be perfectly sound, and taken from a mouth which has the appearance of that of a person sound and healthy ; not that I believe it possible to transplant an infection of any kind from the circulatin* juices although we know from experience that it may be done bf

what the toor*hted ^ T thr' 7hi! SCi°n t0°th should be le» * an what he tooth was the place of which it is to supply. This cannot

the two teeih lu 1 V JUd9D* fr°m the size of the b°d*s of port on the hoi f, f?gS ^ "0t alwa?s bear a» ex^t proportion to the body, it sometimes happens that this method fails Also it is not a ways in our nower tn inA™ *. . .metnod ta',s' in some cases the body oWSoffr this manner, for one transplanted sha/be quite Ts o^ he^oni"0 " *■ ^ in these cases we must iudcre from uJZ? , g onty remaining : side; but even tha, to^^£^$«* °" *■ oppose It has been supposed that we run n„ " i il tooth fron, a jou% subject; but th s is^o'^securitv't^ "" "t'0," "u ^^cunty, tor a complete REPLACING A SOUND TOOTH, ETC. 97 tooth is of the same size in the young as the old.* To remedy this inconvenience as much as possible, the scion tooth should be that of a female, for female teeth are in general smaller than those of men; but the inconvenience still remains whenever a female is the subject of this operation. Some women have such small teeth that it is almost impossible to fit them. When the fang of the scion tooth is larger than that which it is intended to supply, it must be made smaller, and only in that part where it exceeds. But the necessity of this should be avoided if possible, for a tooth that is filed has lost all those inequalities which allow it to be held much faster. If, however, some part must be removed, it should be done so as to imitate the old tooth as much as possible. The best remedy is to have several people ready whose teeth in appearance are fit, for if the first will not answer, the second may. I am persuaded this operation has failed, from a tooth being forced in too tight, for let us reflect what must be the consequence of such practice. A part of the soft covering of the tooth, or lining of the socket, is squeezed between two hard bones, so that all circulation of juices is prevented ; a mortification in that part takes place; and in consequence of that a gum-boil, and the loss of all union between tooth and socket, so that the tooth drops out. It will be hardly necessary to mention that the sooner the scion tooth is put into its place the better, as delay will perpetually lessen the power upon which the union of the two parts depends.f

Of replacing a sound Tooth when drawn by mistake.

It sometimes happens that a tooth is drawn on an idea that it is diseased, because it gives pain, but appears after the extraction to be perfectly sound. In such a case I would recommend the replacing it, that there may be no loss by the operation ; and the seat of the pain will probably be removed to the next tooth. A tooth beat out by violence should be replaced in the same manner. This ought to be done as soon as possible; however, I would even recommended the experiment twenty-four hours after the accident, or as long as the socket will receive the tooth, which may be for some days. If the tooth be replaced at any time before its life is destroyed, it will reunite with the cavity of the socket, and be as fast as ever. No tooth is excepted from this practice, for although in the grinders there are more fangs than one, yet these fangs will as readily go into their respective sockets as one fang would ; and most probably when the tooth has been beat out, the sockets are enlarged by their giving way. However, the grinders are not so subject to such accidents as

♦Natural History, p. 51, on the Growth of Teeth. f See Natural History of Teeth, pp. 57, 58, for an explanation of the principle upon which the success of this operation depends. 10* 98 HUNTER ON THE TEETH. the fore teeth, both from their situation and from their firmness in the sockets. Where a tooth has been only loosened, or shoved out in part, the patient must not hesitate, but must replace it immediately. As a proof of the success to be expected from replacing teeth, I will relate the following case. A gentleman had his first bicuspis knocked out, and the second loosened. The first was driven quite into his mouth, and he spit it out upon the ground, but immediately picked it up and put it into his pocket. Some hours afterwards he called upon me, mentioned the accident, and showed me the tooth. Upon examining his mouth, I found the second bicuspis very loose, but pretty much in its place. The tooth which had been knocked out was not quite dry, but very dirty, having dropped on the ground, and having been some time in his pocket. I immediately put it into warm water, let it stay there to soften, washed it as clean as possible, and then replaced it, first having introduced a probe into the socket to break down the coagulated blood which filled it. I then tied these two teeth to the first grinder, and the cuspidatus with silk, which was kept on some days, and then removed. After a month they were a* last as any teeth in the head, and if it were not for the remembrance ot the circumstances above related, the gentleman would not be sensible that his teeth had met with any accident. Four years nave now passed since it happened.

Of transplanting a dead Tooth.

The insertion of a dead tooth has been recommended, and I have

asTeh .sThPC?m,nUT f°r S3ny yearLS' If this alway* succeeded as well os the living I would g.ve it the preference, because we are

Tad teXcrn?" °f ""^ them' aS a much ^ater varTty f afwavs retain thp- Pro1curedkthan of H™g ones. But they do not I S known t T ?7' bUt are sl'scePtibIe of stain. However, haveLDeareH ™IJ! f X^rs without any alteration; and some hrgeenePrParhaevernoter "^ * ^S^^ -"ich dead teeth

Of the immediate Fastening of a transplanted Tooth.

is^^t";^^^^.^ «* thing to be done in general, to the two neUbomW .,liDt?ded t0 remain' that is' we?d. If it is an inciw^S^^ TT ?J fk °T ^ to the neck of one of the neiS ' G f,lk should first be tied possible; then the two end^ of the^ ^V^T the 6™ M upon the body of the scion tooth but not h°Uld bf brouSht round former, and tied there ; then it 8h, „u I , "ear the Sum as in the of the other neighbouring tooth as ni ? brought round the neck the first, and tied there. The reason nfV?-§-Um as ^slUe, as in reason of the difference of the heights IMMEDIATE FASTENING OF A TRANSPLANTED TOOTH. 99

of the silk recommended must appear evident, it being our intention to keep the tooth close to the bottom of the socket. If the transplanted tooth be a bicuspis, the same mode of tying may be followed; but the silk may be brought over its grinding surface between the two points, by which it will be better confined than in any other way. It sometimes happens that the body of the scion tooth is either too long, too thick, or in such a position as to be pressed upon by the teeth of the opposite jaw. Great care should be taken to prevent this, as the opposite teeth constantly oppose the fastening of those which are transplanted, in every motion of the jaw. To remedy this inconvenience, we have recommended smaller teeth than those lost; but even when they are of a proper size imother respects they will in some cases still touch the opposite teeth. When this arises from length of the tooth, a small portion may be filed off from the cutting edge with great safety. If it is owing to the thickness of the scion tooth, and in the upper jaw, some part may be filed off the hollow or concave surface of the tooth directly opposed to it. When it is owing to the position of the teeth, the same thing may be done with propriety. By attending to this circumstance in the tying, this inconvenience may in many cases be prevented: however, if it should not be in the power of the dentist to prevent it by the above-mentioned method, then he should bring them forwards by tying them to a silver plate, a little more bent than the circle of the teeth, and resting at each end upon the neighbouring teeth. Where a tooth does not exactly fit, but is too short, then there arises a difficulty with the patient whether he ought to consult propriety or beauty. The tooth should be as much in the socket as it can be with ease, for although in that case it is too short, appearances must give way. The patient must now finish the rest. He must be particularly attentive at first, and give it as little motion as possible. In many cases a soreness will continue some days, and the gums will swell; in others there will neither be soreness nor swelling. The patient must take great care not to catch cold, or expose himself to any of the other common causes of fever, for such accidents are very likely to prevent the success of this operation. This caution is more necessary in the winter than the summer. The tooth in some will begin to be fast in a few days, and the gum will cling close to it; while in others many weeks will pass before this happens, though the tooth may become fixed at last. I have seen the transplanted tooth come a little way out of the socket, and, without any art being used, retire into it as far as at first. The silk is to be removed sooner or later, according as the tooth is more or less fast; in some people after a fortnight, in others not till some months after the operation. This operation, like all others, is not attended with certain success. It sometimes happens that the two parts do not unite, and in 100 HUNTER OX THE TEETH. such cases the tooth often acts as an extraneous bodv,* and instead of fastening, the tooth becomes looser and looser, the gum swells, and a considerable inflammation is kept up, often terminating in a gum-boil. Jn some cases, where it is also not attended with success, there are not these symptoms; the parts appear pretty sound, only the teeth do not fasten, and sometimes drop out. It also happens that transplanted teeth have a very singular operation performed on them while in the socket; the living socket and gum finding this body kept in by force, so that they cannot push it out, set about another mode of getting rid of it, by eating away the fang till the whole is destroyed, exactly similar to the wasting of the fangs of the temporary teeth in the'young subject t J have all along supposed, that where this practice is attended with success there is a living union between the tooth and socket, and that they receive their future nourishment from this new master My reasons for supposing it were founded on experiments on other parts,! in animals, and also observations made on the practice itself; for first I observed that they kept their colour, which is very different from that of a dead tooth; for a living tooth has a degree of transparency, while a dead one is of an opaque chalk v white Secondly, there are instances of their becoming diseased, in the same manner as an original living tooth; at lelst the fol owin* case favours strongly this opinion. °

tratn^nfrJl 72h * §entIerman of the <"% of London had a tooth extremelTwP 1 ,hWf ^^'^ S<Td' and fixed in its new **ket extremely well; about a year and a half after two spots were

a dlcTy "hJ™ ^ if *? *?* °f the t0°th' wh^S a decay they were exactly similar to specks, or the first aDoearanceof decay, which come upon natural living teeth! Pa ia so sometimes felt in the transplanted tooth But what puts it beyond a doubt is, that a livino- tooth when "dSveiirof8the6 H™* W «o animal, wil^IaTo^ i^sho vn bv le folio? l ^ C«mU™^ with the tooth, a ib snown oy tne following experiments *

deep^nd^-!?'" ^ " f TT'S head: lhe" ™de " prelly Serf theftnn of ZT T- 'he Vh-ick part »f««^ comb, and

in eeedti:°nr,,renlsba :s tJ je^"6 ^r1™^^ and Ibe teeth beim, softened bv this m ""? P u°'° " Weak acid' into two halves, i°n to^R&^%la«to™*>«>*to«ai vesseis of the toeth ,e„ in^/lnd^ X.T that £e°t£

* I say often, because T do not suppose that h .1 body.; because we know that dead teeth hive It *lw,ays acts as an extraneous the sockets or gums in the least. We mU th r years with°"t affecting times the case with transplanted livincr teeth herefore ^pose that it is some- X Natural History, p. 57. DENTITION. 101 nal surface of the tooth adhered everywhere to the comb by vessels similar to the union of a tooth with the gum and sockets.* f

Teeth, at their first formation, and for some time while growing, are completely inclosed within the sockets and gums,J and in their growth they act upon the inclosing parts in some degree as extraneous bodies; for while the operation of growth is going on in them, another operation is produced, which is a decay of that part of the gum and socket that covers the tooth, and which becomes the cause of the very disagreeable and even dangerous symptoms which attend this process. As the teeth advance in size, they are in the same proportion pressing against these sockets or gums, from whence inflammation and ulceration are produced. That ulceration which takes place in dentition is one of the species which seldom or never produces suppuration; however, in some few cases I have found the gums ulcerated, and the body of the tooth surrounded with matter; but I believe this seldom happens till the tooth is near cutting the skin of the gums. As this is a disease of an early age, and indeed almost begins with life, its symptoms are more diffused, more general, and more uncertain at such an early period than those of any disorder of fullgrown people, putting on the appearance of a great variety of maladies; but these symptoms become less various and less hazard-

* I may here just remark, that this experiment is not generally attended with success. I succeeded but once out of a great number of trials. f [It is unnecessary in the present day to enter into any dis«ission on the merits of an operation now, I believe, wholly discontinued-. From the experiments which Hunter made on the transplanting of i^feth from the jaw to other situations, and the successful result of several^fHTtem, the operation in question became a favourite one with him ; andwjjrtppears to have been very frequently performed either by himself oru^Whisairections. The frequent failures which occurred, even in the operatfJWfself, and still more the severe results which very often succeeded its performance at different periods, have very properly induced almost all subsequent practitioners to abandon its employment. Nothing but the sanguine expectations created in an ardent mind, by the interesting results which followed his first experiments, could account for a man of so sound a judgment having followed up a practice so obviously objectionable. The experiment with which this section is closed has, however, an interest attached to it far more important than its having given rise to the temporary adoption of an objectionable operation. In the result of this experiment may be found an interesting collateral argument in favour of the organized structure of the teeth, and their actual living connexion with the body. The vessels of the tooth, we are told, were well injected, and the external surface adhered everywhere to the comb by vessels. To what purpose are these vessels formed, what object can possibly be fulfilled by the existence of a vascular pulp in the internal cavity, and a vascular periosteum covering the external surface,—so obviously vascular that it was well injected from the vessels of a cock's comb, into which it had been transplanted,—unless they are intended to nourish the bony substance of which the tooth consists, and to form the medium of its connexion with the general system ?] % Natural History, pp. 38 and 39, PI. V. f. 15. 102 HUNTER ON THE TEETH. ous as the child advances in years, so that the double teeth of the child, and still more so the second set of teeth, or those of the adult, are usually cut without producing much disturbance. These symptoms are so various in different children, and often in the same child, that it is difficult to conceive them to be from the same origin, and the varieties are such as seem to be beyond our knowledge. They produce both local and constitutional complaints, with local sympathy. The local symptoms we may suppose to be attended with pain, which appears to be expressed by the child when he is restless] uneasy, rubs his gums, and puts everything into his mouth. There is generally inflammation, heat, and swelling of the gums, and an increased flow of saliva. The constitutional or general consequential symptoms are fever and universal convulsion. The fever is sometimes slight and sometimes violent. It is very remarkable both for its sudden rise and declension; so that in the first hour of this illness the child shall be perfectly cool, and in the second flushed and burning hot, and in the third temperate again. The partial or local consequential symptoms are the most various and complicated; for the appearance they put on is in some degree determined by the nature of the parts they affect; wherefore they imi ate various diseases of the human body. These symptoms we shall describe in the order of their most frequent occurrence. -Uiarrhoea, costiveness, loss of appetite, eruptions on the skin, especially on the face and scalp, cough, shortness of breath, with a Kind of convulsed respiration, similar to that observable in the nooping cough, spasms of particular parts, either by intervals or 2nuefd'aB( increased secretion of urine, and sometimes a dimi- £, 5 secretion, a discharge of matter from the penis, with gonorrn-La ^ '" Dg WatGr' imitatinS exactly a violent

nnJifth^^N1. glandS °f thG n6ck are at this time ^t to swell; w 11 rlf hta53 Str°nS tendencyt0 the scrofula, this irritation win promote that disease.

allT^ennamf^b?i,many-0ther s^mPtoms with which we are not at their foln'^" Pat,GnutS m general not bei"g ab*e to express namefv thf' ^f 7 fhe S^mPtoms °f ^ tsetse are dangerous, attack^ vftal n»rt Th*' T*' ^P** thoS& loCal symptoms°which be fatal but t£ 1 l" feV°r' lnde?d' se,dom lasts «> long as to

a e^' "iX^^Zt^ ""TT/h 4-^ often violent, do not kill; and when "vn f / althoug\very the patient is generally free from dan7erP n " V1*] V™?**™** being obtained by the sufferings of nS,' a* °U"ty to the whole quence to life. brings ot a part which is of little conse- Universal sympathy seems to be the fW **&,.♦ c ■ ■ ■ .n genera! appear, as such in those ^ose lotun°d parhaT^ DENTITION. 103 tion, and irritability, are not yet formed; for in such subjects, when one partis irritated, the whole sympathizes, and general convulsions ensue. But as the sensations and partial irritability begin to be formed, each part, in some degree acting for itself, acquires its own peculiarities; so that when a local disease takes place in a patient that is very young, it is capable of giving a general disposition to sympathize; but as the child advances, the power of sympathy becomes partial, there not being now in the constitution that universal consent of parts; but some one part is found which has a greater aptitude than the rest to fall in with the local irritation; therefore the whole disposition for sympathy is directed to some particular part, and it sympathizes according to its own peculiar action. This arises from the different organs acquiring more and more their own independent sensations as the child grows older, and gradually losing the power of sympathizing with one another, so that by the age of six years few parts suffer but those immediately affected; and in adults, who cut their teeth, we almost always find the pain and other symptoms confined to the part, or only local sympathy taking place, such as a swelling of the side of the face. But as the symptoms become more confined, the suffering part is often much more violently affected than where it has a power of taking in the other parts. Therefore we find that in adults the pain of cutting a grinder is frequently excessive, and that the local inflammation is very considerable, and often of long continuance.* This is not the case with children; their pain does not appear to be so very considerable, and we are certain that the local inflammation is not great; that it is confined to the very parts which suffer, and is not diffused over the face; so that in children the symptoms of sympathy are often more violent than those of the parts themselves. Though it is generally a fact that the symptoms of dentition in adults are confined to the parts immediately injured, it is not always or certainly so; for sometimes, as will appear from Case the fourth, there will be the strongest symptoms imaginable from sympathy, which seems to be owing to a peculiar aptitude in the constitution to universal sympathy. These pains in the adult are often periodical, having their regular and fixed periods, from which circumstance they are often supposed to be aguish, and the bark is administered, but without effect. Medicines for the rheumatism are likewise given, with as litle success, when a tooth will appear, and disclose the cause of the complaint; and by lancing the gums the cure often is performed, but the disease will recur if the gum happens to heal over the tooth, which it will very readily do if the tooth is pretty deep. As these teeth are generally slower in their growth than the others, and more especially those which come very late, they become the cause of many returns of the symptoms. How far children under this circumstance are subject to paroxysms of the disease is not an easy thing to determine; but from many of * Vide Case the third. 104 HUNTER ON THE TEETH. their sympathetic symptoms going off and returning, it would appear that they have also their exacerbation.

The cure of diseases arising from dentition, from their nature, can only be temporary and local, even when it is directed to the real seat of the disease; and certainly every method of cure which is not so directed must prove ineffectual, as it can only operate by destroying the effect. Opiates, indeed, will in some degree take off the irritation, by destroying the sensibility of the part; but surely it wrould be better at once to remove the cause than to be attempting from time to time to remove or palliate the effect. When the sympathy is partial, and not in a vital part, it would be better to allow it to continue than cure it, because it may by such means become universal; for instance, if it is a diarrhoea, the best way is to allow it to go on, or at least only correct it if too violent, which is often the case. I have seen cases where the stomach and intestines have sympathized so much as almost to threaten death. The small quantity of nourishment that the stomach could admit of was hurried off by the intestines.

As far as my experience has taught me, to cut the gum down to the teeth appears to be the only method of cure. It acts either by taking off the tension upon the gum, arising from the growth of the tooth, or by preventing the ulceration which must otherwise take place. It often happens, particularly when the operation is performed early in the disease, that the gum will reunite over the teeth; in which case the same symptoms will be produced, and they must be removed by the same method. I have performed the operation above ten times upon the same teeth, where the disease had recurred so often, and every time with the absolute removal of the symptoms. It has been asserted that to cut the gum once will be sufficient, not only to remove the present but to prevent any future bad symptoms from the same cause. This is contrary to experience and the known laws of animal economy; for frequently the gum, from its thickness over the tooth, or other causes, must necessarily heal up again; and the relapse is as unavoidable as the original disease. f tit**/ PreJUdlCe ?revai s aSainst this Practice, from an objection that if the gum is lanced so early as to admit of a reunion, the

ready ,. give Way «o pressure ^'o^TU-wth^E CUTTING THE GUMS. 105 either the part itself or the constitution. Therefore each operation tends to make the passing of the teeth easier. When the teeth begin to give pain, we find them generally so far formed as to be easily discerned through the gum. The fore teeth are to be observed at first, not on the edge of the gum, but on the fore part, making risings there, which appear whiter than the other parts; and it may be observed that the gums are broader than usual. At this period the incisions must be made pretty deep, till the tooth be felt with the instrument, otherwise little effect will be produced by the operation; and this is the general rule with respect to the depth of the incision in all cases. When the grinders shoot into the gum, they flatten the edge of the gum and make it broad. These teeth are more easily hit by the instrument than the fore teeth. The operation should not be done with a fine-pointed instrument, such as a common lancet, because most probably the point will be broken off against the tooth, which will make the instrument unfit for going on further, if more incisions are required. A common lancet with its point rounded is a very good instrument, but an instrument something like a fleam would be of the most convenient shape. There is no need of any great delicacy in the operation, the gums being very insensible parts; and to cut through the whole gum down to the teeth with certainty, when they are pretty deep, requires some force. The gums will bleed a little, which may be of service in taking off the inflammation. I never saw a case where the bleeding either proved inconvenient or dangerous. If it ever should be troublesome, I think there could be no great difficulty in stopping it. In general, no application is necessary: the gums soon unite at the most distant part from the tooth, if it lies deep; and if it be more superficial, the thin gum soon shrinks back over the tooth, leaving it bare, and decays. The cutting of the dentes sapientiae is often attended with an inconvenience which does not attend the others; and this happens, I believe, only when they come very late, viz. when the jaws have left off growing. This arises from the want of room in the jaws for these late teeth ; a circumstance which produces an addition to the other inconveniences arising from dentition. When it takes place in the upper jaw, the tooth is often obliged to grow backwards ; and in such a position it sometimes presses on the interior edge of the coronoid process, in shutting the mouth, and gives great pain. When it takes place in the lower jaw, some part of the tooth continues to lie hid under that process, and covered by the soft parts, which are always liable to be squeezed between that tooth and the corresponding tooth in the upper jaw. To open very freely is absolutely necessary in these cases; but even that is often not sufficient. Nothing but drawing the tooth, or teeth, will remove the evil in many cases. 11 106 HUNTER ON THE TEETH. CASES.

It would be endless to give histories of cases exemplifying each symptom of dentition; I shall only relate a few which are singular, and which, being extraordinary, will the better enforce the propriety, in all cases, of the cure I have recommended. Case I.—A young child was attacked with contractions of the flexor muscles of the fingers, and also of the toes. These contractions were so considerable as to keep her fingers and thumb constantly clenched, and so irregularly that they appeared distorted. All the common anti-spasmodic medicines were given, and continued for several months, but without success. I scarified the gums down to the teeth, and in less than half an hour all the contractions had ceased. This, however, only gave relief for a time. The gums healed; the teeth continued to grow, and filled up the new space acquired by the scarifications; and the same symptoms appeared a second time. The former operation was immediately performed, and with the same success. Case II.—A boy, about two years of age, was taken with a pain and difficulty in making water, and voided matter from the urethra. I suspected that, by some means or other, this child might possibly be affected by the venereal poison; and the suspicion naturally fell on the nurse. These complaints sometimes abated, and would go off altogether, and then return again. It was observed at last that they returned only upon his cutting a new tooth. This happened so often, regularly and constantly, that there was no reason to doubt that it was owing to that cause. Case III.—A lady, about the age of five or six and twenty years, was attacked with a violent pain in the upper jaw, which at last extended through the whole side of the face, similar to a violent toothache from a cold, and was attended with consequent fever. It was treated at first as a cold ; but, from its continuance, was afterwards supposed to be nervous. The case was represented to me from the country, and I gave the best directions that I could, on a representation of the symptoms. She came to London some months after, still labouring under the same complaint. Upon examining the mouth, I observed one of the pour's of the dens sapientiae ready to come through. I lanced the gums, and the disorder gave way immediately. A lady, about the same age, was attacked with a violent pain in the left side of her face. It was regularlv periodical, coming on at six o'clock in the evening. She took the Peruvian bark, which had no effect. She took antimonials, and Dover's powder, which also were equally ineffectual. But one of the points of the dens sapiential of the upper jaw of the same side appearing, showed the cause, and indicated the remedy. The gums were lanced, and the pain ceased. EXPLANATION OF PLATES. PLATE I.

Fig. 1. A front view of the upper and lower-jaws of an adult, with a full set of teeth, a a a the upper-jaw. b b the lower-jaw. Fig-. 2. A side view of both jaws in the same state, a a the upper-jaw. b b the lower-jaw. c its ascending process, d the root of the coronoid process, e the condyle, ////the fluted alveolar processes.

Fig. 1. The basis of the upper-jaw, with a full set of teeth, showing the cutting edges and grinding surfaces of the teeth of the upper-jaw. aaaa the four incisores. b b the two cuspidati. c c the four bicuspides. d d the six grinders. Fig. 2. A view from above and behind of the lower-jaw, with a full set of teeth ; showing the cutting edges and grinding surfaces of the teeth of that jaw, with the coronoid processes, and condyles for articulation. a a a a the four incisores. b b the two cuspidati. c c the four bicuspides. d d the six grinders, e e the coronoid processes. // the condyles. Fig. 3. The moveable cartilage of the joint of the lower-jaw. a the cut surface of a longitudinal section of it: the lower and cancave surface is what is articulated with the condyle, the upper and convex surface is what is in contact with the temporal bone. Fig. 4. A side view of the upper and lower-jaw, in which the outer plate of the alveolar process was taken off to expose the fangs of the teeth in their sockets. The length of each fang is at once seen with respect to its neighbour, and this kind of articulation pointed out at one view.

/Vw. i. Two views of the sixteen teeth of one side of both jaws, taken out of their sockets to expose the whole of each tooth. Row 1. The teeth of the upper-jaw, seen from the outside. Bow 2. The same view of the teeth of the lower-jaw : the five single are similar to those of the upper-jaw, but the grinders in this have only two fano-s. a the incisors, b the cuspidati. c c the bicuspides. d d 108 HUNTER ON THE TEETH. the two first grinders, having three fangs, e the third grinder, or dens sapientiae, having also three fangs. Row 3 & 4. A side view of the same teeth, showing that the incisores and cuspidati, in this view, differ from the former view more than the bicuspides or grinders. Row 3. a a the two incisores of the upper-jaw, showing the hollowed inner surface of the body of these teeth, b the cuspidatus, showing the same, c e the bicuspides, showing the two points at the basis of each. The first of them has a forked fang. Fig. 1—7. Show the cavities of the teeth in the incisores, cuspidatus, bicuspidatus and molares. Fig. 8. A molaris of the lower-jaw, with part of its fangs sawed off, to show that the sides of the cavity or canal have grown together, and divided it into two small canals, which are represented by the four dark points. Fig. 9—10. The cavity in the body of the teeth seen in transverse sections. Fig. 11—12. Longitudinal sections of the molares to expose the cavities. Fig. 13. The basis of a molaris whose points were worn down, and the bony part which projected into those points exposed. Fig. 14. A molaris whose bony part is wholly exposed, and only a circle of enamel left, covering the sides all round. Fig. 15—16. A lateral view of the enamel of a molaris and bicuspis, cut longitudinally. Fig. 17. A cuspidatus worn so much down as to expose the whole end of the bony part, a circle only of enamel remaining. Fig. 18. An incisor slit down its axis, to show the enamel upon the body of the tooth, covering much more of the convex than of the concave part. Fig. 19. An incisor, showing the same as fig. 17. Fig. 20. A horse's tooth slit down its whole length, to show how the enamel is intermixed with the bony part, and that it passes through the whole length of the tooth. The enamel is presented by the white lines, which are penniform, showing the striated texture of the enamel. Fig. 21. The grinding surface of a horse's molaris, to show the irregular course of the enamel. Fig. 22. An incisor a little magnified, slit down its middle, to show that the enamel is striated, and that the stria? are turned towards the centre. Fig. 23. A grinder in the same state, to show the same circumstances. Fig. 24. The basis of a molaris broken through, showing that the enamel is striated in this view also, and that the stria? point to the centre. N.B. The teeth must be broken to show these facts Fig. 25. An old tooth whose basis has been worn down below the original termination of the cavity in the body of the tooth, and that end has been filled up, in the same proportion with new matter, to prevent the cavity being exposed. This matter i,nf,^ i , sented in the figure. * dafker C°loUr' aS rePre" Fig. 26. Another tooth in the same state. EXPLANATION OF PLATES. 109 PLATE IV.

Fig. 1. One side of the upper and lower-jaw of a subject about eight or nine years of age, where the incisores and cuspidati of the foetus were shed, and their successors rising in new sockets; showing likewise the two grinders of the child, with the bicuspides forming underneath. The adult grinder was ready to cut the gum ; and the second grinder of the lower-jaw is lodged in the root of the coronoid process, and in the upper-jaw it is in the tubercle. Fig. 2. Part of the lower-jaw cut through at the symphysis. The incisor of the child is standing in its socket, and the adult incisor forming in a distinct socket underneath. Fig. 3. Another view of the same piece of the jaw, to show that the bicuspides are formed in distinct sockets of their own, and not in the socket of the grinder which stands above.

Fig. 1—2. The lower and upper-jaw of a fcetus, from which part of the gum and bony socket is taken off, to expose the membrane which incloses the teeth. Fig. 3. The lower-jaw of a new-born child, where this inclosing membrane is opened, to show the bodies of the teeth which were covered by it. The blood-vessels which run in its substance are also exposed. Fig. 4. That part of the jaw and gum which contains the cuspidatus : the whole is a little magnified. The membrane is opened and turned off on each side, and the fore-part is turned down : the upper part of the pulp is covered with its bony shell, which is seen by its want of vessels. Fig. 5 and 6. The pulp of a cuspidatus, and the pulp of a grinder, magnified. The ossifications are removed to show that the pulps are of the same shape with the teeth which are formed upon them. As far down on the pulp as the vessels are seen, the ossification had advanced; which shows that it is more vascular where the operation of ossification is going on. The lower ragged edges represent the borders of the capsular turned down. Fig. 7. One of the grinders of the lower-jaw, sawed down to expose the two cavities or canals leading to the body of the tooth, where they unite and form a square cavity. In these two canals are seen two arteries, which run on to the common cavity, and there ramify. The veins are not injected. The whole is magnified. In the body of the tooth may be observed a number of strata, each of which is lost in the circumference of the tooth. Fig. 8. An incisor prepared and magnified in the same manner, showing the same circumstances in that tooth. Fig. 9. The production of the permanent rudiment by means of a process given off from the temporary, shown in a lower incisor. 110 HUNTER ON THE TEETH. Fig. 10. The rudiments in a more advanced stage; the permanent being now inclosed in its proper socket, though still connected with the temporary. Fig. 11. The connection between the temporary tooth and the permanent rudiment, as it exists after the former has passed through the gum. Fig. 12. A view of the lower-jaw, after the whole temporary teeth have passed through the gums, showing the relative position of the temporary teeth, and the rudiments of the permanent at this period. Fig. 13. Shows the formation and cavity of the fangs of the molares. The upper row are those of the lower-jaw, and the lower those of the upper. A A, a a is the common cavity in the body of the tooth; which in the second, a a, is deeper than in the first. B shows the bony arch thrown over the mouth of the cavity, and dividing that into two openings, which give origin to the two fangs. C D D the progress of these fangs. F a molaris of the upper-jaw, where the mouth of the cavity is a little tucked in, at three different points from which three ossifications shoot. G shows these ossifications, and the beginning of these fangs. H I K show the gradual growth of these fangs. Fig. 14. Is a comparative view of the incisors and grinders of the child and adult; for the better understanding of which they are sawed down the middle, showing, in a side view, the gradual increase of these teeth. The uppermost row is of the child, and the lower of the adult. abed show the gradual growth of the body, fangs and cavity of the incisors of both ages, efg show these circumstances in the grinders. Fig. 15. 1—7 show the gradual growth of a single tooth, from its formation nearly, to its being almost complete. Fig.- 16. A series of grinders of the child, from their being complete, to their utmost decay, a is a grinder of the upper-jaw nearly complete, in which the three fangs are almost formed, b has some of its fang absorbed, c more, d still more, c nearly all gone, and /the whole of the fangs gone, only the neck and body remaining. Fig. 17. A series of incisors in the same state. No. 1. a completely formed tooth ; 2, the fang somewhat decayed ; 3, more so ; 4, still more; 5, The fang almost gone; and 6, the whole fang gone, the neck and body only remaining. Fig. 18. A horse's tooth that was just ready to be shed. The three parts of the tooth, which stand up, inclosed the rising end of the young tooth. This is all that was left of a long tooth. PLATES HUNTER ON THE HUMAN TEETH. PLATE I. Fig. 1. PLATES TO HUNTER ON THE TEETH. 113 Fig. 2. PLATE I. 12 Fig. 1. PLATES TO HUNTER ON THE TEETH.

4$ PLATES TO HUNTER ON THE TEETH. 125 PLATE V. Fig. 1. PLATES TO HUNTER ON THE TEETH. 127 Fig. 14. PLATE V. f§ li ^J*!^® Fig. 16. Fig. 18. Fig. 12. A TREATISE ox

THE VENEREAL DISEASE. BY JOHN HUNTER, F.R.S. With Mottn \ BY GEORGE G. BABINGTON, SUKGEOX OT ST. GEORGE'S HOSPITAL; FORMEBLY SUBGEON OF THE LOCK HOSPITAL, ETC. HASWELL, BARRINGTON, AND HASWELL, 293 MARKET STREET. 1841. CONTENTS. Preface of the Editor.

Introduction. 1. Of Sympathy.—2. Of Morbid Actions being incompatible with each other.— 3. Of the comparative Powers of different parts of the Body—from Situation —from Structure.—4. Of Parts susceptible of particular Diseases.—5. Of Inflammation.—6. Of Mortification.

Chap. I.—Of the Venereal Poison. 1. Of the first Origin of the Poison.—2. Began in the Human Race, and in the Parts of Generation.—3. Of the Nature of the Poison.—4. Of the greater or less Acrimony of the Poison.—5. Of the Poison being the same in Gonorrhoea and in Chancre.—6. Of the Cause of the Poisonous Quality—Fermentation —Action. Chap. II.—The Mode of Venereal Infection.

Chap. III.— Of the Different Forms of the Disease. Varieties in different Constitutions.

Chap. IV.—Of the Lues Venerea being the Cause of other Diseases.

Chap. I.— Of Gonorrhoea. 1. Of the Time between the Application of the Poison and Effect.—2. Of the Difficulty of Distinguishing the virulent from the simple Gonorrhoea.—3. Of the common final intention of Suppuration not answering in the present Disease.—4. Of the Venereal Gonorrhoea.—5. Of the Seat of the Disease in both Sexes.—6. Of the most common Symptoms, and the Order of their Appearance.—7. Of the discharge.—8. Of the Chordee.—9. Of the Manner in which the Inflammation attacks the Urethra.—10. Of the swelled Testicle. —11. Of the Swellings of the Glands from Sympathy.—12. Of the Diseases of the Lymphatics in a Gonorrhoea.—13. Short Recapitulation of the Varieties in the Symptoms.

Chap. II.— Of the Gonorrhoea in Women. Of the Proofs of a Woman having this Disease.

Chap. HI.—Of the Effects of the Gonorrhoea on the Constitution in both Sexes.

Chap. IV.—Of the Cure of Gonorrhoea. 1. Of the Different Modes of Practice—Evacuants—Astringents__2. Of Local Applications—Different kinds of Injections—irritating—sedative—emollient —astringent.

Chap. V.— Of the Cure of Gonorrhoea in Women. Chap. VI.—Of the Treatment of the Constitution in the Cure of the Gonorrhoea.

Chap. VII.—0/Me Treatment of occasional Symptoms of the Gonorrhoea.

1. Of the Bleedings from the Urethra.—2. Of preventing painful Erections.— 4 CONTENTS. 3. Of the Treatment of the Chordee.—4. Of the Treatment of the Suppuration of the Glands of the Urethra.—5. Of the Treatment of the Affection of the Bladder from Gonorrhoea.—6. Of the Treatment of the swelled Testicle. —7. Of the Decline and Termination of the Symptoms of Gonorrhoea.

Chap. VIII.—Observations on the Symptoms which often remain after the Disease is subdued. 1. Of the Remains of the disagreeable Sensations excited by the original Disease. —2. Of a Gleet.—3. Of the Cure of Gleets—Constitutionally—Locally.— 4. Of the remaining Chordee.—5. Of the Continuance of the Irritation of the Bladder.—6. Of the Remaining Hardness of the Epididymis.

Chap. I.— Of Diseases supposed to arise in consequence of Venereal Inflammation in the Urethra of Men. Of Strictures.

Chap. II.— Of the permanent Stricture.

1. Of the Bougie.—2. Of the Treatment of the permanent Stricture.—3. Of the Cure of Stricture by Ulceration.—4. Of the Application of a Caustic to Strictures.

Chap. III.— Of Strictures in Women. 1. Of the Cure of Strictures in Women.—2. Of the Gleet in consequence of a Stricture.

Chap. IV.—Of Stricture attended icith Spasmodic Affection.

Chap. V.—Of some circumstances attending the Use of Bougies—their Figure and Composition. Of a New Passage formed by Bougies.

Chap.VI.—Of Diseases in consequence of a permanent Stricture in the Urethra.

1. Of the Enlargement of the Urethra.—2. Of the Formation of a new Passage for the Urine.—3. Of Inflammation in the Parts surrounding the Urethra.— 4. Of the Treatment of the Inflammation in the surrounding Parts.__5. Of the Effects of Inflammation in the surrounding Parts upon the Constitution. —6. Of Fistulae in Perinteo.—7. Of the Operation for Fistula? in Perineeo.

Chap. VII.—Of some other Affections of the Urethra.

1. Of the Spasmodic Affections of the Urethra.—2. Of the Cure of the Spasmodic Affections of the Urethra.—3. Of the Paralysis of the Urethra —4 Cure of the Paralysis of the Urethra.-5. Of Caruncles or Excrescences in the Urethra.—b. Of the Cure of the Excrescences or Caruncle.

Chap. VIII.—Of the swelled Prostate Gland. Of the Treatment of the Swelled Prostate Gland.

Chap. IX.-Ofthe Diseases of the Bladder, particularly from the beforementioned Obstructions to the Urine.

L ^vSernTte111 ^Of ^f ^ns of the Urethra and Bladder do not ex-

Obstruction arising from Pressure or Spasm ' Para'yS1S °f the Bkdder from

Chap. X.-Ofa Suppression of Urine and Operations for the Cure of it. 1. Of allowing a Catheter to remain in the Urethra and Bladder.-2. Of the CONTENTS. 5 increased Strength of the Bladder.—3. Of the Distension of the Ureters.—4. Of Irritability in the Bladder independent of Obstructions to the Passage of the Urine.—5. Of the Cure of simple Irritability of the Bladder.—fj. Of a Paralysis of the Acceleratores Urinae.

Chap. XL— Of the Discharge of the Natural Mucus of the Glands of the Urethra.

Of the Discharge of the Secretions of the Prostate Gland and Vesiculse Seminales.

1. Of Impotence depending on the Mind.—2. Of Impotence from a want of proper Correspondence between the Actions of the diflerent Organs.

Chap. XIII.—Of the Decay of the Testicle. PART IV.

Chap. I.—Of Chancre. Of the Phimosis and Paraphimosis.

Chap. II.—Of Chancres in Women.

Chap. III.—General Observations on the Treatment of Chancres. 1. Of the Destruction of a Chancre.—2. Of the Cure of Chancres—Local Applications.—3. Of the Treatment of Phimosis in consequence of, or attended with, Chancre.—4. Of the common Operation for the Phimosis produced by Chancres.—5. Of the Constitutional Treatment of Phimosis.—6. Of the Treatment of the Paraphimosis from Chancres.—7. Of the Cure of Chancres by Mercury given internally.

Chap. IV.—Of the Cure of Chancres in Women.

Chap. V.—Of some of the Consequences of Chancres—and the Treatment of them.

1. Of Dispositions to new Diseases during the Cure of Chancres.—2. Of Ulceration resembling Chancres.—3. Of a Thickening and Hardening of the Parts. -^. Of Warts.—5. Of Excoriations of the Glans and Prepuce.

Chap. II.—Of Buboes in Women.

Chap. III.—Of the Inflammation of Buboes, and the Marks that distinguish them from other Swellings of the Glands.

Chap. IV.— General Reflections on the Cure of Buboes. 1. Of Resolution of the Inflammation of the Absorbents on the Penis—2 Of the Resolution of Buboes in the Groin.—3. Of the Resolution of Buboes in Women.-4. Of Buboes in other Parts.—5. Of the Quantity of Mercury necessary for the Resolution of a Bubo.—6. Of the Treatment of Buboes when they suppurate.

Chap. V.—Of some of the Consequences of Buboes. 1* 6 CONTENTS. PART VI.

Chap. I.—Of the Lues Venerea.

1 Of the Nature of the Sores or Ulcers proceeding from the Lues Venerea.—2. Of the Matter from Sores in the Lues Venerea compared with that from Chancres and Buboes.—3. Of the Local Effects arising from the Constitution considered as critical—Symptomatic Fever.—4. Of the Local Effects arising from the Constitution considered as critical—Symptomatic Fever.—4. Of the Local and Constitutional Forms of the Disease never interfering with one another.—5. Of the supposed Termination of the Lues Venerea in other Diseases.—6. Of the Specific Distance of the Venereal Inflammation.—7. Of the Parts most susceptible of the Lues Venerea.—Of the Time and Manner in which they are affected—what is meant by Contamination, Disposition, and Action—Summary of the Doctrine.

Chap. II.—Of the Symptoms of the Lues Venerea.

1. Of the Symptoms of the first Stage of the Lues Venerea.—2. Experiments made to ascertain the Progress and Effects of the Venereal Poison.—3. Of the Symptoms of the Second Stage of the Lues Venerea.—4. Of the Effects of the Poison on the Constitution.

Chap. III.— General Observations on the Cure of the Lues Venerea.

1. Of the Use of Mercury in the Cure of the Lues Venerea.—2. Of the Quantity of Mercury necessary to be given.—3. Of the sensible Effects of Mercury upon Parts.—4. Of the Action of Mercury.—5. Of the different Methods of giving Mercury—Externally—Internally.—6. Of the Cure of the Disease in the Second or Third Stage.—7. Of Local Treatment.—8. Of Abscesses—Exfoliation.—9. Of Nodes on Tendons, Ligaments, and Fascise.—10. Of Correcting some of the Effects of Mercury.—11. Of the form of the different Preparations of Mercury when in the Circulation.—12. Of the Operation of Mercury on the Poison.—13. Of Gum Guaiacum, and Radix Sarsaparillae, in the Venereal Disease.

Chap. IV.—-Of the Effects remaining after the Disease is Cured, and of the Diseases sometimes produced by the Cure. 1. General Observations on the Medicines usually given for the Cure.—2. Of the Continuance of the Spitting.

Chap. V.—Of Preventing the Venereal Disease. PART VII.

Chap. I.—Of Diseases resembling the Lues Venerea, which have been mistaken for it. Of Diseases supposed to be Venereal, produced by Transplanted Teeth. PREFACE. Of all the works of John Hunter, there is none on which he bestowed more labour, or which he was more solicitous to perfect, than his treatise on the Venereal Disease. " I am resolved," said he, to a friend, " that it shall not be a mere bookseller's job, every subsequent edition rendering the former useless. The truth of the doctrines I have proved so long as to reduce them to conviction ; and, in order to render the language intelligible, I meet a committee of three gentlemen,* to whose correction every page is submitted." It would seem that this correction of style was adopted in the second edition. On comparing it with the first we find numberless verbal alterations, which were evidently intended to render the expressions more lucid and more elegant. It is doubtful whether much has been gained by the change. The language is certainly less rugged, but it is also less forcible, and occasionally less distinct and decided. However, as the corrections have extended in some instances to points of more consequence than style, the second edition must undoubtedly be considered as containing the latest experience and ultimate conclusions of the author. The third edition was published after his death by Sir Everard Home, who has in general followed the text of the first edition, and has introduced some passages which were certainly never written by John Hunter.

* The three gentlemen were, Dr. (afterwards Sir Gilbert) Blane, Dr. George Fordyce, and Dr. David Pitcairn, and with these Mr. Marshall appears to have been associated, 8 HUNTER ON THE VENEREAL DISEASE. For these reasons the text of the second edition has been followed as the most genuine : but as the alterations by Sir E. Home profess to be derived from materials left by the author, it has been thought best not to omit them entirely, and consequently such of them as are more than verbal have been added in notes at the bottom of the page. It cannot be disputed that the work thus produced bears marks of the mind that gave it birth. To form a just estimate of its merits, it is necessary to compare it with the books on the same subject which had previously appeared in this country. These seem, for the most part, to have been written less with the design of increasing the knowledge of the disease, than with a view to temporary notoriety, and to the emoluments which such notoriety might bring. John Hunter always had higher objects. He has laboured to apply to this disease the general principles of pathology, and to subject it to the same scrutinizing analysis which generally guided his philosophical researches. The facts he has selected from his daily experience are valuable, not for their singularity, but for the inferences to which they lead. Where the practice was previously uncertain and contradictory, he has often established systematic principles of treatment; and where the practice was right, he has placed it on a sure foundation, by substituting the deductions of reason for the habits of empiricism. With respect especially to diseases of the bladder and urethra, the observations contained in this work first threw light on those affections, and formed the basis on which our present accurate knowledge of them has ben founded. Yet at the same time it must be admitted that this treatise is not without defects, and that the reputation of of John Hunter rests more on his other works than on this. Many of the remarks are rather theoretical than practical, and some of the doctrines have not obtained that general assent which has crowned most of his other labours. The causes of these imperfections are to be found in the nature of the subject and the character of the author. PREFACE. 9 A little reflection will show that the Venereal Disease was less adapted than many other subjects to the peculiar genius of John Hunter. The faculties which chiefly distinguished him from other men of science, and which generally insured his success, were an ardour and an energy which nothing could damp, and an industry which nothing could tire. Under the influence of these qualities he pushed his investigations with unexampled activity, and brought to light a multitude of facts, which the less energetic inquiries of other philosophers had failed to discover. Wherever our previous knowledge was partial and indistinct, the new facts which he collected by observation, or discovered by dissection, or established by experiment, illuminated the whole subject, and substituted the clear distinctness of the day for the obscurity and uncertainty of twilight. His view was always large and comprehensive; and by combining these new discoveries with what was known before, he deduced without difficulty laws which had eluded previous research, and then verified his deductions by a further observation and a more extended experiment. It is more to the activity of his inquiries than to the strength of his reasoning powers that we owe his discoveries. Indeed, his powers of reasoning were scarcely on a level with his other faculties; but the errors of his logic wereperpetually corrected by the variety and accuracy of his experiments. Now it so happens that in the Venereal Disease he had little opportunity for the exercise of his usual means of investigation. Experiments on animals are impossible in this case, as the disease seems to be confined to the human species. Dissections give little information, for the virus itself altogether eludes our sight; and such of its effects as are not obvious, are for the most part too minute to be distinguished by the eye. As most syphilitic symptoms occur in parts which are superficial and exposed to view, their general form and character have long been familiar to surgeons : the minuter changes are not discoverable by I0 HUNTER ON THE VENEREAL DISEASE.

simple inspection, nor easily demonstrable to the senses. The casual observations of every day were open to John Hunter as to others, but he was exposed to the same difficulties which had checked the progress of his predecessors, and was liable to be misled by the same causes of error. In the Venereal Disease we have abundance of facts, of a certain kind, on record. It is not additional experience that we want, but a more correct discrimination, which would enable us better to understand our experience, to disentangle its perplexities, and reconcile its apparent contradictions. The facts noticed by John Hunter are not sufficiently novel or important to throw of themselves much additional light on the pathology of the malady. He was therefore reduced to the necessity of reasoning from the old experience, and of endeavouring, by subjecting it to a more correct process of induction, to correct the errors and improve on the knowledge of those who had preceded him. Consequently it is not surprising that his labours should have been less successful here than in some other branches of pathology, and that he should often have failed in removing the obscurity which envelops this malady. It may even be doubted whether his natural appetite for generalization has not sometimes misled him, and whether, /;in his desire to ascertain a general law, he has not sometimes abandoned his hold of the acknowledged facts of the disease, and left it even more obscure than before. There was one way in which the investigation might have been conducted, which would have promised higher results. The symptoms of the Venereal Disease, though very obvious, are at the same time infinitely various, and even to this day they have never been accurately discriminated. If the Author had bent the full powers of his keen and penetrating mind to tracing out in the first instance a correct description of each separate symptom ; if he had then pursued the research so as to have ascertained in each case the particular structure affected, and the particular nature of the morbid alteration, he would have laid PREFACE. 11 a firm basis for his reasoning, and could not have failed to elucidate both this malady and many which resemble it. It is probable that he would have so ascertained the laws which regulate the peculiar action of the venereal virus, as to have left no room for confounding its effects with diseases from other causes. It is probable that he would have explained the apparent contradictions in the effect of remedies, and, by appropriating each to its peculiar class of affections, have rendered the system of treatment no longer dubious and empirical, but clear and intelligible. It is certain that he would have opened the way for subsequent discoveries to an extent which cannot be calculated, and that, not only in the disease under consideration, but also in other maladies which have hitherto been little studied by pathologists, especially in eruptions and other diseases of the skin. That such a task as this was well adapted to the powers of John Hunter cannot be questioned. The descriptions he has given in the work before us are sufficient of themselves to establish his reputation. In accuracy and distinctness they have never been surpassed, and they remain at the end of half a century the standard definitions to which all subsequent writers have referred. But the plan here sketched out would have been toilsome and long. It would have required the labour of a life. The fruit which it promised was remote and uncertain. It might never have been gathered by the author, but might have remained to be the spoil of a future generation. He followed his natural inclination. He preferred the more delusive, apparently the more direct road which has seduced so many philosophers. He sought to arrive at the general laws of nature at once by conjecture; rather than, by a close and detailed study of her inferior operations, to ascend, step by step, through a slow and gradual induction to those laws which govern her general procedure. " Altera (via) a sensu et particularibus advolat ad axiomata maxime generalia, atque ex iis principiis eorumque immota veritate 12 HUNTER ON THE VENEREAL DISEASE.

judicat et invenit axiomata media; altera a sensu et particularibus excitat axiomata, ascendendo continenter etgradatim, ut ultimo loco perveniatur ad maxime generalia."* But though this treatise is tainted more than any other of the works of John Hunter with the vice of a too hasty generalization, yet it is full of practical observations of the highest value, and must always form an essential part of the study of every surgeon who wishes to make himself acquainted with the disease of which it treats. In the present Edition it has been attempted to render it more generally useful by engrafting on it the labours of other surgeons. The opinions of the author have been treated with the respect which is due to his high reputation; but where important facts have been brought to light by others, either in confirmation or in correction of his principles, they have been presented to the reader, in order that he may have before him in one view the present state of the science, and that by comparing the reasoning of others with that of the author, he may be enabled to form a just opinion of the truth or the error of his conclusions.

G. G. BABINGTON. Golden Square, June 13, 1835.

N.B. The Editor's Notes are distinguished from the Author's by being placed within brackets [ ]. The various readings of the text, according to the third edition, by Sir Everard Home, are placed with that gentleman's name affixed. * Bacon, Aphorism, xix. A TREATISE OS THE VENEREAL DISEASE. INTRODUCTION.

Two motives have induced me to publish the following treatise. In the first place, I am not without hope, that several new observations contained in it will be deemed worthy of the public attention ; in the next place, I am desirous to have an opportunity of showing, from whom some opinions that have made their way into the medical world originated. But as much of the theory which will often be referred to in the course of this work is peculiar to myself, it seems necessary to give an introductory explanation of some parts of it, in order that the terms used may be the more intelligible to the reader.

I divide sympathy into two parts, universal and partial. Universal sympathy is an affection wherein the whole constitution sympathises with some sensation or action. Partial sympathy is an affection wherein one or more distinct parts sympathise with some local sensation or action. The universal sympathies are different in different diseases; but those that occur in the venereal' disease are principally two, the symptomatic fever and the hectic fever. The symptomatic fever is an immediate effect of some local injury, and seldom takes place in the venereal disease in any great degree under any of its forms, except in the case of a swelled testicle, which is itself an instance of a partial sympathy; the symptomatic fever here, therefore, is an universal sympathy arising from a partial one. The hectic fever is an universal sympathy with a local disease, which the constitution is 14 HU.NTER ON THE VENEREAL DISEASE. not able to overcome. This takes place oftener and in a greater degree in the lues venerea than in any other form of the disease. I divide partial sympathy into three kinds ; the remote, the contiguous, and the continuous. The remote is where there appears to be no visible connexion of parts from whence we can account for such effects, as in the case of pain of the shoulder in an inflammation of the liver. The contiguous is that which appears to have no other connexion than what arises from vicinity or contact of separate parts, an instance of which we have in the stomach and intestines sympathising with the integuments of the abdomen. The continuous is where there is no interruption of parts, and the sympathy runs along from the irritating point, as from a centre, which is the most common of all sympathies. We have an example of this in the spreading of inflammation.

§ 2. Of Morbid Actions being incompatible with each other.

The venereal disease is not only suspected to be present in many cases where the nature of the disorder is not well marked, but it is supposed that it can be combined with other diseases, such as the itch and the scurvy. Thus, we hear of pocky itch and of scurvy and the venereal disease combined; but this supposition appears to me to be founded in error. I have never seen any such cases, nor do they seem to be consistent with the principles of morbid action in the animal economy. It appears to me, beyond a doubt, that no two actions can take place in the same constitution, or in the same part, at one and the same time. No two different fevers can exist in the same constitution, nor two local diseases in the same part, at the same time; yet as the venereal disease, when it attacks the skin, bears a resemblance to those symptoms which are vulgarly called scorbutic, they are often supposed to be mixed, and to exist in the same part. What has been called a scorbutic constitution is no more than a constitution very susceptible of an action producing eruptions on the skin whenever an immediate cause takes place ; and there are some parts of the body more susceptible of this than others, in which, therefore, a slighter immediate cause is sufficient to excite the action ; but the easy susceptibility with respect to one disease is not a reason why a constitution should not likewise be susceptible of other diseases. A man may have the pox and the small-pox at the same lime; that is, parts of his body may have been contaminated by the venereal poison, and the small-pox may take place, and both diseases may appear together, but not in the same parts. It both were consequences of fever, and each followed the fever nearly about the same time, it would be impossible for each to have its respective eruption, even in different parts, at the same time : two fevers, antecedent to these different diseases, cannot be co-existent. From this principle I think I may fairly put the following queries. INTRODUCTION. 15 Does not the failure of inoculation, and the power of resisting many infections, sometimes arise from the person's having at the same time some other disease, and therefore being incapable of a new action 1 Does not the great difference in the time, from the application of the cause to the appearance of the effect, in many cases, depend upon the same principle ? It has been sometimes observed that the puncture in the arm has shown no sign of inflammation in fourteen days after the application of the variolous poison. Has there not been another disease in the constitution at the time of inoculation ? Does not the cure of some diseases depend upon the same principle ? The suspension or cure of a gonorrhoea by a a fever may be an instance of this. Let me illustrate this principle still further, by one of many cases which have come under my own observation. On Thursday, March 16, 1775, I inoculated a gentleman's child, in whose arms it was observed I made large punctures. On the Sunday following he appeared to have received the infection, a small inflammation or redness appearing round each puncture, and a small tumour above the surface of the skin having been observed. On the 20th and the 21st the child was feverish, but I declared that the fever was not variolous, as the inflammation had not at all advanced since the 19th. On the 22d a considerable eruption appeared, which was evidently the measles: upon this the sores on the arms appeared to go back, becoming less inflamed. On the 23d he was very full of the measles, the punctures on the arms being in the same state as on the preceding day. On the 25th the measles began to disappear. On the 26th and 27th the punctures began to look a little red. On the 29th the inflammation increased, and there was a little matter formed. On the 30th he was seized with fever. The small-pox appeared at the regular lime, went through its usual course, and terminated favourably. In like manner, it may be observed that the venereal disease makes its appearance at different periods after infection. Is not this explicable on the same principle 1

§ 3. Of the comparative Powers of different Parts of the Bodyfroin Situation—-from Structure.

We shall have occasion to observe, that the parts affected assume the morbid action more readily and continue it more rapidly when near to the source of the circulation than when far from it; for the heart exerts its influence upon the different parts of the body in proportion to their vicinity to it; and the more distant that the parts are, the weaker are their powers. This is perhaps better illustrated by disease than by any actions in health, for in health we have no comparative trials, as no two parts of the machine, at unequal distances from the heart, can be thrown into equal action, and therefore no conclusions can be drawn. It may be observed that all the vital parts are near the heart. 16 HUNTER ON THE VENEREAL DISEASE. In diseases we see mortification arising from debility, in the extremities oftener than in other parts, more especially if the person is tall; the heart not propelling the blood to these distant parts with equal force. In such a state of constitution, those who labour under a hemiplegia are often found to die at last from a mortification in the extremities of the paralytic side. In some of these cases the arteries give way, and allow of an extravasation of the blood, and therefore we may reasonably suppose that they are proportionally weak in health. We also find that such extravasation commonly begins in the extremities. This principle is not only evident in these two diseases, but also in every disease that can affect an animal body. It appears in the readiness with which diseases come on and proceed in parts distant from the source of the circulation, and also in the steps towards a cure. Parts differ not only in their powers, in proportion as they are nearer or further from the heart, but likewise according to their peculiar structure, whereby they vary as much in the progress of morbid actions as in the operations of health. An animal body is composed of a varietybof substances, as muscle, tendon, cellular membrane, ligament, bone, nerve, &c. We have therefore an opportunity of observing the comparative progress of diseases in them, and their comparative powers of performing a cure ; and we find that they differ very much from one another in those respects. How far these differences take place in all diseases, I have not been able to determine; but should suppose, that in specific diseases, as scrofula and cancer, there is in general no difference in the mode of action in any of the structures,* these diseases producing the same specific effects in all the parts that are capable of being affected by them ; but in diseases arising from accident a great difference in the degrees of action takes place, the parts from such a cause being allowed to act according to their natures; which observation holds good also in the venereal disease. This difference appears to be chiefly in the degrees of strength and weakness in resisting, morbid action. The less the natural powers of action are in any particular structure of parts, the less they are able to resist disease ; therefore bone, tendon, ligament, and cellular membrane go through their morbid actions more slowly than muscle or skin; and this principle is applicable to the venereal disease.

§ 4. Of Parts susceptible of particular Diseases.

There are some parts much more susceptible of specific diseases than others. Poisons take their different seats in the body as if allotted for them. Thus we have the skin attacked with what are vulgarly called scorbutic eruptions, and many other diseases ; it is • Here it is to be understood, that we do not include those parts which have a greater tendency to specific diseases than what many others have; as the lyn> phatics to the scrofula, the breast to the cancer. INTRODUCTION. 17 also the seat of the small-pox and the measles ; the throat is the seat of the hydrophobia and the hooping-cough. The scrofula attacks the absorbent system, especially the glands. The breasts, testicles, and the conglomerate glands are the seat of cancer. The skin, throat, and nose are more readily affected by the lues venera than the bones and periosteum ; which, on the Other hand, suffer sooner than many other parts, particularly the vital parts, which perhaps are not at all susceptible of the disease.

I consider common inflammation to be an increased action of the smaller vessels of a part, joined with a peculiar mode of action, by which they are enabled to produce the following effects; to unite parts of the body to each other, to form pus, and to remove parts of the solids. These effects are not produced by a simple increase of action or enlargement of the vessels, but by a peculiar action, which is at present perhaps not understood. These three effects of inflammation I have called distinct species of inflammation. That which unites parts I have called the adhesive inflammation; that which forms pus, the suppurative inflammation ; and that which removes parts, the ulcerative inflammation. In the adhesive inflammation the arteries throw out coagulable lymph, which becomes the bond of union. This, however, is not simply extravasated, but has undergone some change before it leaves the arteries, since in inflamed veins it is found lying coagulated upon the internal surface of the vessel, which could not have happened if simply extravasated. In the suppurative inflammation a still greater change is produced upon the blood before it is thrown out by the arteries, whereby it is formed into pus; which change is probably similar to secretion. In the ulcerative inflammation, the action of the arteries does not remove the parts: that office is performed by the absorbent vessels which are brought into action. In the two first species of inflammation there must be a change in the disposition and mode of action of the arteries; for the suppurative species cannot be considered as simply an increase of the action of the adhesive, as its effects are totally different; but in the third species there is probably no change of action in the arteries from that of the second: the action only of the absorbents being superadded, by which solid parts, and of course the arteries themselves, are removed.

Mortifications are of two kinds, one preceded by inflammation, the other not. But as the cases of mortifications which will be mentioned in this work are all of the first kind, I shall confine my observations to that species. I consider inflammation as an increased action of that power 3 18 HUNTER ON THE VENEREAL DISEASE. which a part is naturally in possession of. This increased action, in healthy inflammations at least, is probably attended with an increase of power; but in inflammations which terminate in mortification there is no increase of power. On the contrary, there is a diminution of power which, joined to an increased action, becomes the cause of mortification, by destroying the balance which ought to subsist between the power and action of every part. If this account of mortifications be just, we shall find it no difficult matter to establish a rational practice. But, before we attempt this, let us just take a view of the treatment hitherto recommended, and see how far it agrees with our theory. It is plain, from the common practice, that the weakness has been attended to, but it is as plain that the increased action has been overlooked; and therefore the whole aim has been to increase the action, with a view to remove the weakness. The Peruvian bark, confectio, cardiaca, serpentaria, &c, have been given in as large quantities as the case appeared to require, or the constitution could bear; by which means an artificial or temporary appearance of strength has been produced, while it was only an increased action. The cordials and wine, upon the principle on which they have been given, are rationally administered ; but there are strong reasons for not recommending them, arising from the genera-1 effect which all cordials have of increasing the action without giving real strength; and the powers of the body are afterwards sunk proportionally as they have been raised : by which nothing can be gained, but a great deal may be lost; for, in all cases, if the powers are allowed to sink below a certain point, they are irrecoverable. The local treatment has been as absurd as the constitutional. Scarifications have been made quite to the living parts, that stimulating and antiseptic medicines might be applied to them, such as turpentines, the warmer balsams, and sometimes the essential oils. Warm fomentations have been also applied as congenial to life; but warmth always increases action, and stimulants are improper where the actions are already too violent. Upon the principles here laid down, the bark is the only medicine that can be depended upon, as it increases the powers and lessens the action. Upon many occasions opium will be of singular service by lessening the action, although it does not give real strength. I have seen good effects from it, both when given internally in large doses, and when applied to the part. To keep the parts cool is proper; and all the applications should be cold. The above-mentioned practice is to be kept in view in mortifications that happen in the venereal disease. OF THE VENEREAL POISON. 19 PART I. CHAPTER I.

The Venereal Disease arises from a poison, which, as it is produced by disease, and is capable of again producing a similar disease, I call a morbid poison, to distinguish it from the other poisons, animal, vegetable, and mineral. The morbid poisons are many, and they have different powers of contamination. Those which infect the body either locally or constitutionally, but not in both ways, I call simple. Those which are capable of affecting the body both locally and constitutionally, I call compound. The venereal poison, when applied to the human body, possesses a power of propagating or multiplying itself; and as it is also capable of acting both locally and constitutionally, it is a compound morbid poison. Like all such poisons, it may be communicated to others in all the various ways in which it can be received, producing the same disease in some one of its forms.

§ 1. Of the first Origin of the Poison.

Though the first appearance of this poison is certainly within the period of modern history, yet the precise time and manner of its origin has hitherto escaped our investigation, and we are still in doubt whether it arose in Europe or was imported from America. I shall not attempt to discuss this question; and those who wish to examine at length the facts, authorities, and arguments brought in favour of the latter opinion, may consult Astruc; and for the former, a short treatise* published in 1751, without a name. The author of this treatise appears to have considered the subject very fully, and, as far as reasoning goes on a subject of this kind, proves that the disease was not brought from the West Indies. Not contented with this, he goes on to account for its first rise in Europe; but in this he is not equally successful. The subject is a difficult one, and

* Intitled " A Dissertation on the Origin of the Venereal Disease ; proving that it was not brought from America, but began in Europe from an epidemical Distemper. Translated from the original Manuscript of an eminent Physician. London, printed for Robert Griffiths, 1751." 20 HUNTER ON THE VENEREAL DISEASE. the want of a sufficient number of facts leaves too much room for conjecture. * We shall not, therefore, enter further into this question ; nor is it material to know at what period, and in what country, this disease arose ; but we may in general affirm, that as animals are not naturally formed with disease, or so as to run spontaneously into morbid actions, but with a susceptibility of such impressions as produce such actions, diseases must always arise from impressions made upon the body; and as man is probably susceptible of more impressions that become the immediate cause of disease than any other animal, and is besides the only animal which can be said to form artificial impressions upon himself, he is subject to the greatest variety of diseases. In one of those self-formed situations, therefore, the impression most probably was given which produced the venereal disease.

§ 2. It began in the Human Race, and in the Parts of Generation.

In whatever manner it arose, it certainly began in the human race, as we know no other animal that is capable of being infected with this poison. It is probable, too, that the parts of generation were the first affected ; for if it had taken place in any other part of the body, it might probably never have gone further than the person in whom it first arose, and therefore never have been known ; but being seated in the parts of generation, where the only natural connexion takes place between one human being and another, except that between the mother and child, it was in the most favourable situation for being propagated ; and as we shall find hereafter, in the history of the disease itself, that no constitutional effect of this poison can be communicated to others, we are led of necessity to conclude that its first effects were local.

§ 3. Of the Nature of the Poison.

We know nothing of the poison itself, but only its effects on the human body. It is commonly in the form of pus, or united with pus, or some such secretion, and produces a similar matter in others, which shows that it is most generally, although not necessarily, a consequence of inflammation. It produces or excites, therefore, in most cases, an inflammation in the parts contaminated ; besides which inflammation, the parts so contaminated have a peculiar mode of action superadded, different from all other actions attending inflammation; and it is this specific mode of action which produces the specific quality in the matter. It is not necessary that inflammation should be present to keep up this peculiar mode of action, because the poison continues to be formed long after all signs of inflammation have ceased. This appears from the following facts: men having only what is called a gleet, or healing chancre, give the disease to sound women; and many OF THE VENEREAL POISON. 21 venereal gonorrhoeas happen without any visible signs of inflammation. In women the inflammation is frequently very slight, and often there is not the least sign of it, for they have been known to infect men though they themselves have had no symptoms of inflammation, or of the disease in any form. Therefore the inflammation and suppuration, when present, are only attendants on the peculiar mode of action, the degree in which they take place depending more on the nature of the constitution than on that of the poison. The formation of matter also, though a very general, is not a constant attendant on this disease, for we sometimes find inflammation produced by the venereal poison which does not terminate in suppuration ; such inflammation I suspect to be of the erysipelatous kind. It is the matter produced, with or wi'thout inflammation, which alone contains the poison, for without the formation of matter no venereal poison can exist. Therefore a person having the venereal irritation in any form, not attended with a discharge, cannot communicate the disease to another. To communicate the disease, therefore, it is necessary that the venei'eal action should first take ^>lace, that matter should be formed in consequence of that action, and that the matter should be applied to a sound person or part. That the venereal disease is to be propagated only by matter is proved every day by a thousand instances. Married men contract the disease, and not suspecting that they have caught it, cohabit with their wives, even for weeks. Upon discovering symptoms of the disease they of course desist; yet in all my practice I never once found that complaint was communicated under such circumstances, except where they had not been very attentive to the symptoms, and therefore continued the connexion after the discharge had appeared. I have gone so far as to allow husbands while infected, but before the appearance of discharge, to cohabit with their wives in order to save appearances, and always with safety. I could carry this still further, and even allow a man who has a gonorrhoea to have connexion with a sound woman, provided that great care be taken to clear all the parts of any matter, by first syringing the urethra, making wafer, and washing the glans.' f

* The last sentence omitted.—Home, f[The omission of the last sentence in Sir Everard Home's edition is not without reason, since the truth of the doctrine is, to say the least, very questionable, and the practice which is deduced from it is undoubtedly most mischievous and reprehensible. The author's doctrine is, that the virus resides in pus, or some such secretion, and hence he draws two practical conclusions: 1. That when there is no pus, or puriform secretion, the disease cannot be communicated. So that before the appearance of a gonorrhoea, or after the healr ing of a chancre, there is no possibility of infection. 2. That even when pus actually exists, vet if particular care be taken to rer 3* " 22 HUNTER ON THE VENEREAL DISEASE. The matter which is impregnated with this poison, when it comes in contact with a living part, irritates that part, and inflammation is the common consequence. It must be applied either in a fluid state, or rendered fluid by the juices of the part to which it is applied. There is no instance where it has given the infection in the form of vapour, as is the case in many other poisons.

move it in the first instance, by very careful ablution, the individual may have connexion with a sound woman without danger of infecting her. The second conclusion cannot be too strongly reprobated. Ii is opposed to every day's experience ; and from the omission of the passage in Sir E. Home's edition, it may be supposed that further observation had led the author himself to change his opinion before the termination of his life. The former position also is by no means free from danger, as will be seen by the following instances, which are far from singular : A married woman was seized with the usual symptoms of gonorrhoea, which greatly surprised her, as her husband was free from complaint. On questioning, however, the husband, he confessed that he had had connexion with a common girl about a week before his wife complained ; but he positively asserted that he had had no discharge or uneasiness whatever, and certainly then showed no signs of disease. In about four days afterwards, that is to say, nearly a fortnight after the impure connexion, and a week after he must have communicated the disease to his wife, a gonorrhceal discharge appeared on him. • A gentleman, when absent from home, exposed himself to the hazard of infection. At the end of three days he returned home, and in about four days afterwards his wife had a gonorrhoea. On the tenth day after the connexion the gentleman first perceived a discharge, and the other symptoms of gonorrhoea. But it may be said, that though such cases show that the conclusion at which the author has arrived is practically unsafe, they by no means disprove the truth of the general principle on which it was founded. It may be said, that in these cases it is an error to suppose that there is no purulent secretion ; that in the very early stage of a gonorrhoea it is probable that the pus is too small in quantity to flow from the urethra; that it lodges in the lacunae, and is washed out by the urine, and is thus concealed from observation, but that it not less really exists ; and that the position therefore remains untouched,—that where there is no matter there can be no infection. However, there is another class of cases which go still further to throw doubts on the truth of this doctrine. A gentleman was exposed to infection when in London. A day or two afterwards he set off for Ireland, where his family resided. He made some stay at Cheltenham, and while there, there appeared on the inner prepuce two or three small indurations or tubercles. He showed them to a surgeon, who convinced himself that there was no ulceration, and did not believe the affection to be venereal. After a short interval he returned to Ireland, these indurations still existing, and infected his wife, who suffered from primary sores. A gentleman had an induration on the penis, which remained after the healing of a chancre. He suffered repeatedly from secondary symptoms, which were a3 often removed by appropriate treatment, but the induration always remained. At length, when a considerable interval had passed without a relapse, and he believed himself to be finally cured, he married, though the induration was not removed. His wife was infected. Cases of this kind might be multiplied without difficulty, and almost necessarily lead to the inference that infection may take place from the contact of a simple chancrous thickening, although no ulceration whatever is present. A misconception of this truth has often led to consequences which are most lanentable. In a considerable proportion of those cases in which a wife has been infected in consequence of marriage with a man labouring under syphilis, the communication seems to have taken place from the cicatrix of a sore which has been healed.] OF THE VENEREAL POISON. 23 § 4. Of the greater or less Acrimony of the Poison.

Venereal matter must in all cases be the same: one quantity of matter cannot have a greater degree of poisonous quality than another: and if there is any difference it is only in its being more or less diluted, which produces no difference in its effects. One can conceive, however, that it may be so far diluted, as not to have the power of irritation. Thus any fluid taken into the mouth, capable of stimulating the nerves to taste, may be so diluted, as not to be tasted. But if the poison can irritate the part to which it is applied to action, it is all that is required: the action will be the same, whether from a large or small quantity, from a strong or a weak solution.* We find from experience that there is no difference in the kind of matter; and no variation can arise in the disease from the matter's being of different degrees of strength, for it appears that the same matter affects very differently diflerent people. Two men having been connected with one woman, and both catching the disease, one of them shall have a violent gonorrhoea, or chancre, while the other shall have merely a slight gonorrhoea. I have known one man give the disease to different women, and some of the women have had it very severely, while in others it has been very slight. The same reasoning holds good with regard to chancres. The variations of the symptoms in different persons depend upon the constitution and habit of the patient at the time. What happens in the inoculation of the small-pox strengthens this opinion. Let the symptoms of the patient from whom the matter is taken be good or bad; let it be from one who has had a great many pustules, or from one who has had but few; let it be from the confluent or distinct kind, applied in a large quantity or a small one, it produces always the same effect. This could only be known by the great numbers that have been inoculated under all these different circumstances.-}- t § 5. Of the Poison being the same in Gonorrhoea and in Chancre.

It has been supposed by many that the gonorrhoea and the chancre arise from two distinct poisons; and their opinion seems to have some foundation, when we consider only the different appearances

* These words added, " Since those men who have taken great pains in washing the parts immediately after connexion have caught the disease, and the symptoms have been equally severe as in others who used no such precaution."— Home. f [Sir E. Home has here added a note, in which he calls in question the truth of this doctrine, as far as regards small-pox. He says that he has in many instances diluted the variolous matter, and always found that the disease produced from such matter was milder than when employed for inoculation in an undiluted state. However, in the venereal disease it must be acknowledged that there are no facts which prove the existence of a similar difference in the virulence of the contagion, or would justify the conclusion that the variations in the symptoms depend on any other cause than the constitution and habit of the recipient.] 24 HUNTER ON THE VENEREAL DISEASE. of the two symptoms, and the different methods of cure; which, with respect to the nature of many diseases, is too often all we have to lead our judgment. Yet, if we take up this question upon other grounds, and also have recourse to experiments, the result of which we can absolutely depend upon, we shall find this notion to be erroneous. If we attend to the manner in which the venereal poison was communicated to the inhabitants of the islands of the South Seas, there are many circumstances which tend to throw light upon the present question. It has been supposed, as no mention is made of a gonorrhoea at Otaheite, that it must have been the chancre that was first introduced into that island, and that of course nothing but a chancre could be propagated there ; for as no gonorrhoea had been communicated, no such disease could take place. But if we were to reason upon all the probable circumstances attending the voyages to that part of the world, we should conclude the contrary: for it was almost impossible to carry a chancre so long a voyage without its destroying the penis; while we know from experience that a gonorrhoea may continue for a great length of time. It is mentioned in Cook's voyage, that the people of Otaheite, who had this disease went into the country and were cured; but when it became a pox it was then incurable. This shows that the disease which they had must have been a gonorrhoea, for we know that it is only a gonorrhoea that can be cured by simple means; and further, if it had been a chancre, and they had been acquainted with the means of curing it, they could also have cured the lues venerea. Wallis left Plymouth in August 1766, and arrived at Otaheite in July 1767, eleven months after his embarkation ; and, if none of his men had the disease when he sailed, there was hardly a possibility of their contracting it anywhere afterwards in the voyage. This appears to be too long for a gonorrhoea to last. But let us suppose even that Wallis carried it thither in his ship, one or two of his crew having the disease : as he stayed there five weeks, it was very possible, even very probable, that such person or persons might have communicated it so quickly as to have become the cause of contamination of the whole crew of his ship. But as this did not happen, it is a presumptive proof that Wallis did not carry it thither. Bougainville left France in December 1766 ; but he touched at several places where some of his people might have got the disease, the last of which places was Rio de la Plata, which he left in November 1767, and arrived at Otaheite in April 1768, five months after. This interval of time agrees better with the usual continuance of the disease than the length of Wallis's voyage; and, therefore, from this circumstance it becomes more probable that Bougainville carried it thither. Besides, it is likely that he could guard his people less against the disease than Waliis; for Wallis could have his choice of men at his first setting out, which was all that • OF THE VENEREAL POISON. 25 was necessary to prevent his carrying the disease with him: for he ran no risk of contracting it afterwards; but although Bougainville had the same advantage at first, yet he had it not afterwards, for his men were in the way of infection in several places, and he had no opportunity of changing them, and probably no great chance of having them cured. The circumstance of the disease being found by Bougainville at Otaheite soon after his arrival, is a kind of proof that he carried it thither himself; for I observed before, that if Wallis had carried it by one man only, this man could in a very few days have so far propagated it as to have spread it through the whole ship's crew; and as Bougainville arrived at the island ten months after Wallis, there was a sufficient time for the inhabitants of the whole island to have been infected, and the ravages of the disease must have been evident to them immediately upon their arrival. Bougainville remained only nine days at the island of Otaheite, and observed nothing of the disease till some weeks after his departure, when it was found that several of the crew were infected, which most probably must have happened in consequence of the poison being carried there by some of his own people. It is also mentioned by Cook that the Otaheiteans ascribed the introduction of the disease to Bougainville; and we can hardly suppose that they would be so complaisant to our countrymen as to accuse Bougainville, when they must have known whether the disease was imported by Wallis or not, especially as they had no reason to be partial in favour of the people who accompanied the latter. But as we find in Cook's last voyage that the disease in every form is now there, and as we have no new intelligence of a gonorrhoea being since introduced, we must suppose that every form of the disease has been propagated from one root, which most probably was a gonorrhoea. If any doubt still remain with respect to the two diseases being of the same nature, it will be removed by considering that the matter produced in both is of the same kind, and has the same properties; the proofs of which are, that the matter of a gonorrhoea will produce either a' gonorrhoea, a chancre, or the lues venerea; and the matter of a chancre will also produce either a gonorrhoea, a chancre, or the lues venerea.* The following case is an instance of a gonorrhoea producing a lues venerea. A gentleman twice contracted a gonorrhoea, of which he was cured both times without mercury. About two months after each, he had symptoms of the lues venerea. Those in consequence of the first infection were ulcers in the throat, which were removed by the external application of mercury; the symptoms in conse-

* The following paragraph is here inserted : "That chancre is sometimes the consequence of gonorrhoea is rendered probable by the following case: A. B. had a gonorrhoea about the beginning of January, 1788; the inflammation went off, the discharge continued : about a month after, a chancre appeared on the glans penis, for which he took mercury, and it got well in about a month."—Home. 26 HUNTER ON THE VENEREAL DISEASE. quence of the second were blotches on the skin, for which also he used the mercurial ointment, and was cured. With regard to the lues venerea proceeding from chancres, instances occur so frequently to every one's observation as to require no further proof here. Since, then, it appears that the gonorrhoea and chancre are the effects of the same poisbn, it may be worthy of inquiry to what circumstances two such different forms of the disease are owing. To account for these two very different effects of the same poison, it is only necessary to observe the difference in the mode of action of the parts affected when irritated, let the irritation be what it may. The gonorrhoea always proceeds from a secreting surface,* and the chancre is formed on a non-secreting surface; and in this last the part to which the poison js applied must, become a secreting surface before matter can be produced. All secreting surfaces in the body being probably similar, one mode of application only is necessary to produce this disease in them all, which is by the poisonous matter simply coming in contact with them. But to produce the chancre, the venereal matter may be applied in three different ways: the first and most certain is by a wound, into which it may be introduced; the second is by applying the matter to a surface with a cuticle, and the thinner that is, it allows the matter to come more readily to the cutis; and the third is by applying the matter to a common sore already formed. The poison, then, being the same in both cases, why do they not always happen together in the same person ? For one would naturally suppose that the gonorrhoea, when it has appeared, cannot fail to become the cause of a chancre ; and that this, when it happens first, must produce a gonorrhoea. Although it does not often happen so, yet it sometimes does ; at least there is great reason to believe so. I have seen cases where a gonorrhoea came on; and in a few days after in some, in others in as many weeks, a chancre has appeared: and I have also seen cases where a chancre has come first; and in the course of its cure, a running and pain in making water have succeeded. It may be supposed that the two diseases arose from the original infection, and only appeared at diflerent times; and their not occurring oftener together would almost induce us to believe it was so, since the matter is the same in both, and therefore capable of producing either the one or the other. I suspect that the presence of one irritation in these parts becomes in general a preventive of the other. I have already observed, that the two parts sympathise in their diseases; and it is possible that

* By secreting surfaces I mean all the passages for extraneous matter, including also the ducts of glands, such as the mouth, nose, eyes, anus, and urethra; and by nonsecreting surfaces, the external skin in general. To which I may add a third kind of surface, leading from the one to the other, as the glans penis, prolabium of the mouth, the inside of the lips, the pudendum ; "which surfaces, partaking of the properties of each, but in a less degree, are capable of being affected in both ways, sometimes by being excited to secretion, and at other times to ulceration. OF THE VENEREAL POISON. 27 that very sympathy may prevent the appearance of the real disease; for if an action has already taken"place which is not venereal, it is impossible that another should take place till that ceases; and it is probable that this sympathy will not cease while the cause exciting it exists; and therefore when both happen in the same person at the same time, I suspect that either the urethra never had sympathised with the chancre, or if it did at first, that the sympathy had ceased, and then the venereal matter might stimulate the parts to action.*

* [There is yet a stronger argument than any which is here given. The author inoculated himself witrTthe matter of gonorrhoea, and the consequence was the production of chancres, followed by bubo, and by secondary symptoms. The experiment is related, at length, in Part VI.; Chap, ii., Sect. 2, of the present work. • . i u But, nevertheless, the identity of the poison of gonorrhoea with that ot chancre has been disputed, and that on no slight grounds. In reply to the argument drawn from the transfer of the venereal disease to the islands in the South'Seas, it has been denied that the disease exists there at all. Mr. Wilson, surgeon to His Majesty^ ship Porpoise, visited Otaheite in 1801, and, after a careful investigation, came to the conclusion that the venereal disease was then unknown in that island. It may also be alleged, that even if the disease actually prevails there, as has been reported by others, it by no means follows that it must have been originally carried thither in the form of gonorrhoea. The facts stated by John Hunter do not bear out his conclusion. Bougainville left the Rio de la Plata in November, 1767, and arrived at Otaheite in April, 1768. It is very possible that a chancre might have existed during the five months which intervened. Cases frequently occur in which primary sores continue for a much longer period, without occasioning any remarkable destruction, and certainly without at all rendering the subject incapable of sexual intercourse. The author affirms that cases occur in which true chancres are produced in those parts which are steeped in the discharge of a gonorrhoea. At the same time he acknowledges that such a circumstance is extremely rare. Yet nothing is more common than that excoriations should arise on the surface of the glans, or on'the inside of the prepuce, from the contact of gonorrhceal matter. These excoriations, if neglected, will last for an indefinite period ; but if the irritating matter is carefully removed by very frequent ablution, they will heal in two or three days, without the least necessity for the exhibition of mercury. Why do they not assume the characters of chancres, or infect the system ? Surely their innocence affords a negative proof of the diversity of the virus, more strong than the very rare occurrence of true chancres can be supposed to give of its identity. For it must not be forgotten, that in these cases the chancre may be attributed to another cause. It may be that the patient has again exposed himself to infection, and that the chancre has arisen from this second exposure. The patient under such circumstances is naturally disposed to conceal his misconduct. Still he may often be induced to confess it on a strict examination ; and in those cases where no such avowal can be elicited, it is perhaps'most reasonable to suspect that it is only prevented by shame. It cannot be denied that there are cases in which secondary symptoms appear to be the consequence of gonorrhoea; but these are so rare, that they must rather be considered as anomalies which we cannot as yet account for, than be admitted in contradiction to the general current of experience. The secondary symptoms in such instances are rarely of an indubitable character. It may be doubted whether distinct copper tubercles ever followed simple gonorrhoea. We have generally a mottled state of the skin, or the lighter and more fugitive forms of lichen, or slight excoriation of the surface of the tonsil. It has been asserted that women who are affected with gonorrhoea alone, will 28 HUNTER ON THE VENEREAL DISEASE. § 6. Of the Causes of the poisonous Quality—Fermentation—Action.

As the consideration and explanation of this point will throw some light upon the disease and cure, I may be allowed to dwell a

frequently produce chancres in those men that are connected with them. Without venturing to give a positive denial to this statement, it may be suggested that its truth has seldom, if ever, been satisfactorily ascertained. The investigation of the surgeon has evidently been confined to the external parts. The interior of the vagina has not been examined: yet it is certain that chancres do occur here, though more rarely, so as to be discovered only by the use of a speculum. When to°this consideration is added all the deception which is constantly practiced in regard to sexual intercourse, it must be allowed that these statements are deserving of very little confidence. There still remains the experiment of John Hunter; and if such experiments were multiplied, it cannot be denied that they would be decisive. That in his case the system was infected with the venereal virus can scarcely be questioned ; but it may be doubted whether the virus might not have been derived from some other source than inoculation with the matter of gonorrhoea. The chances of falling into error are so numerous, that such experiments should be frequently repeated. As it is, the case stands alone; opposed to the general course of experience, and opposed to a series of other experiments which rest on the authority of Mr. Benjamin Bell. The subjects were medical students, who instituted the experiments expressly with the view of deciding this question. They are thus related by Mr. Bell (Bell on Venereal Disease, vol. i. p. 439.) : "' Matter,' says one of these individuals, ' was taken upon the point of a probe, from a chancre on the glans penis before any application was made to it, and completely introduced into the urethra, expecting thereby to produce gonorrhoea. For the first eight days I felt no kind of uneasiness, but about this period I was attacked with pain in passing water. On dilating the urethra as much as possible, nearly the whole of a large chancre was discovered, and in a few days thereafter, a bubo formed in each groin. No discharge took place from the urethra during the whole course of the disease ; but another chancre was soon perceived in the opposite side of the urethra, and red precipitate was applied to it as well as to the other, by means of a probe previously moistened for the purpose. Mercurial ointment was at the same time rubbed on the outside of each thigh, by which a profuse salivation was excited. The buboes, which, till then, had continued to increase, became stationary, and at last disappeared entirely; the chancres became clean, and by a due continuance of mercury a complete cure at last was obtained.' " The next experiment was made with the matter of gonorrhoea, a portion of which was introduced between the prepuce and glans, and allowed to remain there without being disturbed. In the course of the second day, a slight degree of inflammation was produced, succeeded by a discharge of matter, which in the course of two or three days disappeared. " The same experiment was, by the same gentleman, repeated once again, after rendering the parts tender to which the matter of gonorrhoea was applied ; but no chancre ever ensued from it. "Two young gentlemen, while prosecuting the study of medicine, became anxious to ascertain the point in question ; with which view they resolved on making the following experiments, at a time when neither of them had ever laboured under either gonorrhoea or syphilis; and both in these and in the preceding experiments, the matter of infection was taken from patients who had never made use of mercury. " A small dossil of lint soaked in the matter of gonorrhoea was by each of them inserted between the prepuce and glans, and allowed to remain on the same spot for the space of twenty-four hours. From this they expected that chancres would be produced ; but in the one a very severe degree of inflammation ensued over the whole glans and preputium, giving all the appearances of what is usually OF THE VENEREAL POISON. 29 little upon it. It has been supposed by some that the poisonous quality of the matter arises from a fermentation taking place in it as soon as it is formed. But whether this poisonous quality arises from that cause, or whether the animal body has a power of producing matter according to the irritation given, whereby the living powers, whenever irritated in a particular manner, produce such an action in the parts as to generate a matter similar in quality to that which excited the action, is what I am now to consider. In the examination of this subject I shall confine myself to gonorrhoea. In support of either of the two opinions it must be supposed that the venereal matter has, by its specific properties, a power of irritation beyond common matter. I have already observed that it has the power of exciting inflammation even on the common skin, and of forming a chancre, which power is not possessed by common matter. In the first opinion it must be supposed that there is no specific inflammation or suppuration produced by the application of the venereal matter, but only a common inflammation and suppuration; and that the matter capable of producing these effects acts as a ferment upon the new-formed matter, rendering it venereal as soon, or nearly as soon, as it is formed; and as there is a succession of secretions, there immediately follows a

termed gonorrhoea spuria; a considerable quantity of foetid matter was discharged from°the surface of the inflamed parts ; and for several days he had reason to fear that an operation would be necessary for the removal of a paraphimosis. By the use of saturnine poultices, however, laxatives, and low diet, the inflammation abated, the discharge ceased, no chancres took place, and he soon got entirely well. "The other gentleman was not so fortunate. The external inflammation, indeed, was slight, but by the matter finding access to the urethra, he, on the second day, was attacked with a severe degree of gonorrhoea, which continued for a considerable time to give him a great deal of distress; nor did he for upwards of a year get entirely free from it. " By this he was convinced of the imprudence and hazard of all such experiments ; nor could he be prevailed on to carry them further, although they were keenly prosecuted by his friend, who, soon after the inflammation arising from his first experiment was removed, inserted the matter of gonorrhoea on the point of a lancet beneath the skin of the preputium, and likewise into the substance of the glans; but although this was repeated three different times, no chancres ensued. A slight degree of inflammation was excited, but it soon disappeared, without any thing "being done for it. His last experiment was attended with more serious consequences. The matter of a chancre was inserted on the point of a probe to the depth of a quarter of an inch, or more, in the urethra. No symptoms of gonorrhoea ensued; but in the course of five or six days a painful inflammatory chancre was perceived on the spot to which the matter was applied. To this succeeded a bubo, which ended in suppuration, notwithstanding the immediate application of mercury ; and the sore arising from this proved both painful and tedious. Ulcers were at last perceived in the throat; nor was a cure obtained till a very large quantity of mercury was given, under a state of close confinement, for a period of thirteen weeks." These experiments, which strictly accord with the general results of experience must be admitted to disprove altogether the argument derived from the difference between a secreting and a non-secreting surface, and to afford a very strong presumption that, at least in the great majority of cases, the poison of gonorrhoea is not identical with that of chancre.] 30 HUNTER ON THE VENEREAL DISEASE. succession of fermentations. Now let us see how far this idea agrees with all the variety of phenomena attending the disease. First, it may be asked, what becomes of this ferment in many cases where the suppuration does not come on for some weeks after the irritation and inflammation have taken place? In such cases we can hardly suppose the original venereal matter to remain, and to act as a ferment. Secondly, when there is a cessation of the discharge, and no matter formed, which sometimes happens for a considerable time, and yet. all the symptoms recur, what is it that produces this fermentation a second time ? Nothing can, but a new application of fresh venereal matter. When, for example, the irritation is translated to the testicle, and the discharge is totally stopped, as often happens, what becomes of the virus; and how is a new virus formed when the irritation falls back upon the urethra ? Thirdly, if the poisonous quality were produced by fermentation taking place in the matter already formed, it would not be an easy matter to account for the symptoms ever ceasing, for, according to my idea of a ferment, it would never cease to act if new matter were continually added ; nor could anything possibly check it but a substance immediately applied to the part, which could stop or prevent the fermentation in the new matter. But as the venereal inflammation in this species of the disease is not kept up beyond a certain time, the production of the poison cannot depend on fermentation. Fourthly, if it depended on a fermentation in the secreted matter, all venereal cases would be alike, nor would one be worse than another, except from a greater or smaller number of fermenting places. Upon this supposition also all cases would be equally easy of cure, for the fermentation would be equally strong in a slight case as in a bad one. It can only be fermentation in the matter after it has left the vessels. When the venereal matter has been applied to a sore, so as to irritate, it produces a venereal irritation and inflammation. But even this does not always take place, for the common matter from the sore may remove the venereal matter applied, before it can affect the sore so as to produce the venereal inflammation and suppuration there. This experiment I have made several times, and have only once produced the venereal inflammation. But if the venereal matter were capable of acting as a ferment, then it would in all cases produce venereal matter without altering the nature of the sore. The effects produced by venereal poison appear to me to arise from its peculiar or specific irritation, joined with the aptness of the living principle to be irritated by such a cause, and the parts so irritated acting accordingly. I shall therefore consider it as a poison, which by irritating the living parts in a manner peculiar to itself, produces an inflammation peculiar to that irritation, from which a matter is produced peculiar to the inflammation. Let us consider how far this opinion agrees with the various phenomena attending the disease. OF THE VENEREAL POISON. 31 First, the venereal matter having a greater power of irritating than common matter, conveys more the idea of irritation than of fermentation. Secondly, its producing a specific disease with specific symptoms and appearances, shows that it has a specific power of irritation, the living powers necessarily acting according to that irritation. Thirdly, the circumstance of the inflammation having its stated time of appearance and termination, is agreeable to the laws of the animal economy in most cases, as it is a circumstance that takes place in other diseases that have a crisis; and when the disease is longer of duration in some than in others, it is because they are much more susceptible of this kind of irritation ; and there may be perhaps other concurrent circumstances. Fourthly, the venereal inflammation being confined to a specific distance, is more agreeable to the idea of a specific irritation than that of a fermentation. Fifthly, we have a further proof of this opinion, from the appearance of the disease being translated from one part of the body to another, as in the case of the swelled testical, in which the discharge is often stopped or otherwise affected. Sixthly, the discharge often stops from the constitution being attacked by a fever, and returns after some days or weeks, or not at all, according to the continuance of the fever. Now we can plainly see why the fever should put a stop to the discharge, as the disposition produced by it in a part, is very different from that disposition which formed the matter; we can plainly see why the same disposition to form matter should often return; but how that return should be venereal, upon the principles of fermentation, we do not see. Seventhly, the production by art of an irritation of another kind, which is not specific, removes the specific irritation: now an irritation of another kind cannot prevent the fermentation from going on, but may destroy the venereal irritation. Eighthly, the circumstance of particular parts of our body being much more readily irritated than others by the venereal poison, when in the constitution, shows that it arises from an irritation, and that of a particular kind. Ninthly, we know of no other animal that is susceptible of the venereal irritation, for repeated trials have shown that it is impossible to give it to a dog, a bitch, or an ass.* It is much easier to suppose that a dog or an ass is not susceptible of many irritations of which the human body is susceptible, as we find to be the case in all other specific diseases, and most poisons, than that the matter of the human body is susceptible of a change, of which that of the dog or ass is not. This argument is still further supported by comparing the venereal poison with other morbid poisons. The animal poison productive of the hydrophobia seems to be produced by a particular irritation

* I have repeatedly soaked lint in matter from a gonorrhoea, chancre, and bubo, and introduced it into the vagina of bitches, without producing any effect. I have also introduced it into the vagina of asses, without any effect. I have introduced it under the prepuce of dogs without any effect. I have also made incisions and introduced it under the skin, and it has only produced a common sore. I have made the same experiments upon asses, with the same result. 32 HUNTER ON THE VENEREAL DISEASE. affecting certain parts, which shows that if the body, or any part of the body, is irritated, it takes a disposition to act in a peculiar manner, and that this mode of action is capable of secreting such juices as will throw another animal into the same action. In the hydrophobia the throat and its glands are particularly affected ; and how the saliva should become of such a nature from the same kind of matter being either carried into the constitution, or perhaps only by the general sympathy of the constitution with a local infection, and more particularly with the parts about the throat, is not easily to be accounted for, without a supposition either that the absorbed poison circulating can produce a specific constitutional action capable of affecting the throat and glands there, just as the poison of the small-pox affects the skin, or that the circulating poison has power to affect or irritate the glands of the mouth only, or that those parts only are capable of immediately sympathising with the part irritated, as the muscles of the lower jaw are when they produce the locked jaw. If this theory be just, it explains why epidemical diseases, arising from particular seasons, particular constitutions of air, &c, irritate in such a manner as to produce a fever, the effluvia of which shall irritate in the same manner: for it is not in the least material how the original irritation arises ; it is only necessary that there should exist in the animal a power of acting according to the stimulus given by that irritation. CHAPTER II.

THE MODE OF VENEREAL INFECTION.

Every infectious disease has its peculiar manner of being caught; and among mankind there is generally something peculiar in the way of life, or some attending circumstance, which exposes them at one time or other to contract such diseases, and which, if avoided, would prevent their propagation. The itch, for instance, is generally caught by a species of civility, the shaking of hands; therefore the hand is most commonly the part first affected. And as the venereal infection is generally caught by the connexion between the sexes, the parts of generation commonly suffer first. From this circumstance people do not suspect this disease when the symptoms are anywhere else, while they always suspect it in every complaint of those parts. In the lower class of people, one as naturally thinks of the itch when there is an eruption between the fingers, as in young men of the venereal disease whose genitals are affected; but as every secreting surface, whether cuticle or not cuticle, (as was explained OF THE DIFFERENT FORMS OF THE DISEASE. 33 before,) is liable to be infected by the venereal poison when it is applied to it, it is possible for many other parts beside the genitals to receive this disease. Therefore it appears in the anus, mouth, nose, eyes, ears, and, as has been said, in the nipples of women who suckle children affected by it in their mouths, which children have been infected in the birth from the diseased parts of the mother. CHAPTER III.

OF THE DIFFERENT FORMS OF THE DISEASE.

The venereal poison is capable of affecting the human body in two different ways; locally, that is, in those parts only to which it is first applied; and constitutionally, that is, in consequence of the absorption of the venereal pus which affects parts while diffused in the circulation. Between the first and second kind, or the local and constitutional,* certain intermediate complaints take place in the progress of absorption ; these are, inflammations and suppurations, forming what are called buboes, in which the matter is of the same nature as that of the original disease. When the matter has got into the constitution, and is circulating with the blood, it there irritates to action. There are produced from that irritation many local diseases, as blotches on the skin, ulcers in the tonsils, thickening of the periosteum and bones. The local, or first kind, is what I have called immediate, arising immediately upon the application of venereal pus. Of this kind there are two sorts, seemingly very different from one another. In the first there is a formation of matter without a breach of the solids, called a gonorrhoea; in the second there is a breach in the solids, called a chancre. Neither of these two ways in which the disease shows itself is owing to anything peculiar in the kind of poison applied, but to the difference in the parts contaminated. The readiness with which the parts run into violent action in this species of inflammation, is greater or less, according to the nature of the parts affected, which perhaps does not arise from any specific difference in the parts, but is according to the common principle of sensibility and irritability; for we find that the vagina is not so much disposed to inflammation in this disease as the urethra is in the same sex, because it is not so sensible. However, it is possible that there may be some specific disposition to irrita- * I have called this form of the disease constitutional; yet it is not strictly so, for every complaint in consequence of it is truly local, and is produced by the simple application of the poison to the parts. 4* 34 HUNTER ON THE VENEREAL DISEASE.

tion and inflammation in the urethra in man; and what would incline me to think so is, that this canal is subject to be more frequently out of order than any other, producing a great variety of symptoms.

§ 1. Varieties in different Constitutions.

This disease, when it appears in the form either of a gonorrhoea or a chancre, differs very much in the violence of its symptoms in diflerent people. In some it is extremely mild, in others extremely violent. When mild, it is generally simple in its symptoms, having but few, and those of no great extent, being much confined to the specific distance ; but when violent, it becomes more complicated in its symptoms, having a greater variety, and extending itself beyond the specific distance. This does not arise from any variety in the specific virtue of the poison, but from a difference in the disposition and mode of action of the body, or parts of the body, some being hardly susceptible of this or any irritation, others being very susceptible of it, and of every other irritation, so as to readily run into violent action. The venereal irritation, however, does not always follow these rules ; for I have known young men, in whom a sore from common accident has healed up readily, yet the irritation attending a gonorrhoea has been violent, and a chancre has inflamed and spread itself with great rapidity, and even has mortified. On the other hand, I have known young men, in whom a sore from common violence has been healed with great difficulty, yet when they had contracted a gonorrhoea or chancre, the disease has been mild and easily curable. In particular people it is either mild or severe, for the most part, uniformly. In the first-stated dispositions it is not invariably so; but then I believe there is some indisposition at the time. 1 have known several gentlemen who had their gonorrhoeas so slight in common that they frequently cured themselves. But it has so happened that a gonorrhoea has been remarkably severe, and has obliged them to apply for assistance ; but then they were soon attacked with the symptoms of a fever; and when the fever has gone off, the symptoms of the gonorrhoea have immediately become mild. I may now also observe, that when the disease is in the form of a lues venerea, different constitutions are differently affected.— In some its progress is very rapid, in others it is very slow. OF THE LUES VENEREA, ETC. 35 CHAPTER IV.

OF THE LUES VENEREA BEING THE CAUSE OF OTHER DISEASES.

Every animal may be said to have natural tendencies to morbid actions, which may be considered as predisposing causes; and these may be called into action whenever the immediate cause takes place, which may be such as to have no connexion with these tendencies, and cannot therefore be considered as the cause of the disease. One disease excites another, and therefore is supposed to be the sole cause of it. Thus, slight fevers, or colds, small-pox, and measles, become frequently the immediate cause of scrofula ; and certain derangements of the natural actions of the body often bring on the gout, agues, and other diseases: but these diseases will be always more or less, according to the constitution and parts; and the constitutions will differ according to circumstances, which may be numerous; two of these, however, will be local situation and age. In this country the tendency to scrofula arises from the climate, which is in many a predisposing cause, and only requires some derangement to become an immediate cause and produce the whole disease. The venereal disease also becomes often the immediate cause of other disorders, by calling forth latent tendencies to action. This does not happen from its being venereal, but from its having destroyed the natural actions, so that the moment the venereal action and disposition have terminated, the other takes place ; and I have seen in many cases the tendency so very strong that it has taken place before the venereal has been entirely subdued; for by pursuing the mercurial course the symptoms have grown worse ; but by taking up the new disposition, and rendering it less active than the venereal, the venereal has come into action anew ; and these effects have taken place alternately several times. In such cases it is a lucky circumstance when the two modes of treatment can be united; but where they act in opposition it is very unfortunate. If the venereal disease attacks the lungs, although that disposition may be corrected, consumption may ensue; and in like manner where the bones are affected, or the nose, scrofulous swellings or fistula lachrymalis may be the consequence, though the disease may have been cured. Many of the diseases arising from this source appear to be peculiar to such causes, and seem to be formed out of the constitution, the disease, and method of cure. It is therefore difficult to say of what nature such a disease may be; but it will in general have a particular tendency from the constitution; and if we are acquainted with the general tendency of a constitution, we are to suspect that as the strongest cause, and that the disease will partake more 36 HUNTER ON THE VENEREAL DISEASE.

of it than the other. In this country these complaints have most commonly a scrofulous tendency, and are often truly scrofulous, the disease partaking more of that disposition than any other. Parts have also their peculiar tendency to diseases, which are stronger than those of the constitution at large, and when injured they will of course fall into the morbid action arising from such tendencies. Therefore, when parts have had their natural actions destroyed by a venereal irritation, those tendencies will be brought into action ; and, therefore, the diseases arising from the tendencies of such parts are to be kept in view. They will be assisted likewise by local situation and age. In particular countries, and in young people, the tendency to scrofula will be predominant; therefore buboes in them will more readily become scrofulous. In old people they may form cancers; and when in parts of the body which have a particular tendency to cancer, that disease will more readily take place. The want of knowledge and of attention to this subject has been the cause of many mistakes, for whenever such effects have been produced in consequence of the venereal disease, it has immediately been blamed, and not only as a cause, but it has been supposed to be the disease itself. This is an inference natural enough to those who cannot see that a variety of causes are capable of producing one effect, or, in other words, that where the predisposing cause is the same, a variety of immediate causes may produce the same action. It shows great ignorance, however, to suppose the venereal disease can be both the predisposing and immediate cause. When the venereal disease attacks the urethra, it often becomes itself the predisposing cause of abscesses and many other complaints; when it attacks the outside of the penis, forming chancres, they often ulcerate so deep as to communicate with the urethra, producing fistula in the urethra, and often a continued phimosis. In describing diseases which, like the venereal disease, admit of a great variety of symptoms, we should keep a middle line, first giving the most common symptoms of the disease in each form, then the varieties which most commonly occur, and last of all the most uncommon ; but it will not be easy to take notice of every possible variety. Therefore, when a variety occurs not mentioned, it is not to be supposed that the author is leading his readers astray, or is unacquainted with the disease at large. If his general principles are just, they will help to explain most of the singularities of the disease. OF GONORRHOEA. 37 PART II. CHAPTER I.

When an irritating matter of any kind is applied to a secreting surface, it increases that secretion, and changes it from its natural state (whatever that be) to some other. This, in the present disease is pus. When this takes place in the urethra, it is called a gonorrhoea ; and as it arises from the matter being applied to a non-cuticular surface which naturally secretes some fluid, it is of no consequence in what part of the body this surface is; for if in the anus, it will produce a similar discharge there, and a similar effect on the inside of the mouth, nose, eyes, and ears. It is conceived by some that gonorrhoeas may take place without the above-mentioned immediate cause, that is, that they may arise from the constitution, if so, they must be similar to what is supposed to be a venereal ophthalmia. But, from the analogy of other venereal affections proceeding from the constitution, I very much suspect the existence of either the one or the other; for when the poison is thrown upon the mouth, throat, or nose, it produces ulcers, and not an increased secretion like a gonorrhoea. But we never find an ulcer on the inside of the eyelids in those ophthalmias; and gonorrhoeas in the urethra are too frequent to proceed from such a cause. Till about the year 1753, it was generally supposed that the matter from the urethra in a gonorrhoea arose from an ulcer or ulcers in that passage; but from observation it was then proved that this was not the case. It may not be improper to give here a short history of the discovery that matter maybe formed by inflammation without ulceration. In the winter, 1749, a child was brought into the room used for dissection in Covent Garden; on opening of whose thorax a large quantity of pus was found loose in the cavity, with the surface of the lungs and the pleura furred over with a more solid substance similar to coagulable lymph. On removing this from those surfaces, they were found entire. This appearance being new to Dr. Hunter, he sent to Mr. Samuel Sharp, desiring his attendance ; and to him it also appeared new. Mr. Sharp afterwards, in the year 1750, 38 HUNTER ON THE VENEREAL DISEASE. published his Critical Inquiry, in which he introduced this fact, "That matter maybe formed without a breach of substance;" not mentioning whence he had derived this notion. It was ever after taught by Dr. Hunter in his lectures. We, however, find writers adopting it without quoting either Mr. Sharp or Dr. Hunter. So much being known, I was anxious to examine whether the matter in a gonorrhoea was formed in the same way. In the spring of 1753 there was an execution of eight men, two of whom I knew had at that time very severe gonorrhoeas. Their bodies being procured for this particular purpose, we were very accurate in our examination, but found no ulceration. The two urethras appeared merely a little blood-shot, especially near the glans. This being another new fact ascertained, it could not escape Mr. Gataker, ever attentive to his emolument, who was then attending Dr. Hunter's lectures, and also practising dissection under me. He published soon after, in 1754, a treatise on this disease, and explained fully that the matter in a gonorrhoea did not arise from an ulcer, without mentioning how he acquired this knowledge ; and from that time successive writers have repeated the same doctrine. Since the period mentioned above I have constantly paid particular attention to this circumstance, and have opened the urethra of many who at the time of their death had a gonorrhoea, yet have never found a sore in any; but always observed that the urethra, near the glans, was more bloodshot than usual, and that the lacunae were often filled with matter I have indeed seen an instance of a sore a little within the urethra ; but this sore was not produced by any ulceration of the surface, but from an inflammation taking place, probably in one of glands, which produced an abscess in the part, and that abscess opened its way into the urethra. The very same sore opened a way through externally at the fraenum, so that there was a new passage for the urine. Indeed the method of curing a gonorrhoea might have shown that it could not depend upon a venereal ulcer, for there is hardly an instance of a venereal ulcer being cured by anything but mercury, escharotics excepted. We know, however, that most gonorrhoeas are curable without mercury, and, what is still more, without any medical assistance; which, I believe, is never the case with a chancre. This doctrine, that a gonorrhoea does not depend on ulcers, was first taught publicly by Dr. Hunter, at his lectures, in the year 1750 ; but he did not attempt to account for it.

$ 1. Of the Time between the Application of the Poison, and Effect. In most diseases there is a curtain time between the application of the cause and the appearance of the effect. In the venereal disease this time is found to vary considerably, owing probably to the state of the constitution when the infection was received. Each form of the disease also varies in this respect; the gonorrhoea and chancre being earlier in their appearance after contamination than OF GONORRHOEA. 39 the lues venerea, and of the two former, the gonorrhoea appearing sooner than the chancre. In the gonorrhoea, the times of appearance are very different; I have had reason to believe that in some the poison has taken effect in a few hours, while in others it has been six weeks; and I have had examples of it in all the intermediate periods. So far, however, as we can rely upon the veracity of our patients (and further evidence we cannot have), six, eight, ten, or twelve days should appear to be the most common period, though it is capable of effecting some people much sooner, and others much later. I was informed by a married gentleman, who came from the country, and left his wife behind him, that in a frolic he went to a bagnio and had connexion with a woman of the town. The next morning he left her; and he had no sooner got to his lodging than he felt a moisture of the part, and upon inspection he found a beginning gonorrhoea, which proved a very troublesome one. I was told by another gentleman that he had been with a woman overnight, and in the morning the gonorrhoea appeared; and that the same happened to him twice. I was informed by a third gentleman that the discharge appeared in six-and-thirty hours after the application of the poison. In the above-mentioned patients the infection must have arisen from the poison applied at those stated times, as neither of these patients is supposed to have had an opportunity of receiving the infection for many weeks before.* These assertions from men of veracity, and where there could be no temptation to deceive, not even an imaginary one, are sufficient evidences. On the other hand, upon equally good authority, I have been informed that six weeks after the application had passed before any symptom appeared. The patient had strange and uncommon complaints preceding the running, such as an usual sensation in the parts, with most of the other symptoms of gonorrhoea, except the discharge. He had the same complaint about twelve months afterwards, and then it was four weeks from the application of the poison before it appeared, giving for some part of that time the former disagreeable sensations; but from his late experience he.suspected what was coming. From this I am inclined to believe that it seldom or never lies perfectly quiet so long, and that the inflammatory state may take place for some considerable time before the suppurative ; and in these cases there is less disposition for a cure, as the very disposition which forms a running is in general a salutary one, and is an intermediate step between the disease, which is the inflammation, and the cure; for in the time of suppuration a change has taken place in the vessels, producing the formation of matter. If this change should never take place, it is not certain what would be the consequence. Whether the inflammation would go oft* without suppuration, as in many common

* The following case added : "A gentleman had a chancre, which was cured by the internal use of mercury : when the chancre was nearly well, a gonorrhoea made its appearance; this was nearly five weeks after the chancre."—Home. 40 HUNTER ON THE VENEREAL DISEASE. inflammations, I have not been able to determine, but should suspect that it would continue much longer than usual, because the parts have not completed their actions; and I also suspect that such cases always arise from some peculiarity of constitution:

§ 2. Of the Difficulty of distinguishing the virulent from the simple Gonorrhoea.

The surface of the urethra is subject to inflammation and suppuration from various other causes besides the venereal poison; and sometimes discharges happen spontaneously when no immediate cause can be assigned. Such may be called simple gonorrhoeas, having nothing of the venereal infection in them ; though those persons that have been formerly subject to virulent gonorrhoeas are most liable to them. It is given as a distinguishing mark between the simple and the virulent gonorrhoea that the simple comes on immediately after copulation, and is at once violent; whereas the virulent comes on some days after, and gradually. But the simple is not in all cases a consequence of a man's having had connexion with women; it does not always come on at once, nor is it always free from pain. On the other hand, we see many venereal gonorrhoeas that begin without any appearance of inflammation, and I have been very much at a loss to determine whether they were venereal or not; for there is a certain class of symptoms common to almost all diseases of the urethra, from which it is difficult to distinguish the few that arise solely from the specific affection. I have known the urethra sympathize with the cutting of a tooth* producing all the symptoms of a gonorrhoea. This happened several times to the same patient. The urethra is known to be sometimes the seat of the gout ;f I have known it the seat of the rheumatism. The urethra of those who have had venereal complaints is more apt to exhibit symptoms similar to gonorrhoea than the urethra of those who never had any such complaint; and it is generally in consequence of the parts having been hurt by that disease that the simple gonorrhoea comes on, which, perhaps, is also a reason why they are in some measure similar. A discharge, and even pain, attacks the urethra : and strange sensations are every now and then felt in these parts, which may be either a return of the symptoms of the venereal disease without virus, may arise as it were spontaneously, or may be a consequence of some other disease. When it happens in consequence of some former venereal gonorrhoea, it is seldom constant, and may be called a temporary gleet, ceasing for a time and then returning; but in such cases the parts seldom swell, the glans does not change to the ripe cherry colour, nor does it sweat a kind of matter. Such a complaint as a discharge without virus is known to exist, by its coming on when there has been no * Natural History of the Teeth, Part II. p. 110. f Essays and Observations, Physical and Literary, of Edinburgh, vol. iii. OF GONORRHOEA. 41 late connexion with women, and likewise by its coming on of its own accord where there had never been any former venereal complaint, nor any chance of infection. From its commonly going off soon, both in those who have had connexion with women and those who have not, it becomes very difficult in many cases to determine whether or not it is venereal: for it is often thought venereal when it really is not so ; and, on the other hand, it may be supposed to be only a return of the gleet when it is truly venereal. But, perhaps, this is not so material a circumstance as might at first be supposed. These diseases, when they are a consequence of former venereal complaints, may be considered only as an inconvenience entailed on those who have had the venereal gonorrhoea. No certain cure for them is known ; they are similar to the fluor albus in women.

§ 3. Of the common final Intention of Suppuration not answering in the present Disease.

When a secreting surface has once received the' inflammatory action, its secretions are increased and visibly altered. Also when the irritation has produced inflammation and an ulcer in the solid parts, a secretion of matter takes place, the intention of which in both seems to be to wash away the irritating matter; so that it is the end of irritations to produce their own destruction, like a mote in the eye, which, by increasing the secretion of tears, is itself washed away. But in inflammations arising from specific or morbid poisons this effect cannot be produced : for although the first irritating matter be washed away, yet the new matter formed has the same quality with the original; and therefore, upon the same principle, it would produce a perpetual succession of irritations, and of course secretions, even if there were no other cause for the continuance than its own matter. But the venereal inflammation is not kept up by the pus which is formed; but, like many other specific diseases, by the specific quality of the inflammation itself. This inflammation, however, it would appear, can only last a limited time, the symptoms peculiar to it vanishing of themselves by the parts becoming less and less susceptible of irritation. This circumstance is not peculiar to this particular form of the venereal disease; it is, perhaps, common to almost every disease that can effect the human body. From hence it will appear that the consequent venereal matter has no power of continuing the original irritation; and indeed if this were not the case there would be no end to the disease. As the living principle in many diseases is not capable of containing the same action, it also loses this power in the present, when the disease is in the form of a gonorrhoea : and the effect is at last stopped, the irritation ceasing gradually. This cessation will vary according to circumstances : for if the irritated parts are in a state very susceptible of such irritations, in all probability their actions 42 HUNTER ON THE VENEREAL DISEASE. will be more violent and continue longer; but in all cases the dif*- ference must arise from the difference in the constitution, and not from any difference in the poison itself. The circumstance of the disease ceasing spontaneously only happens when it attacks a secreting surface, and when a secretion of pus is produced; for when it attacks a non-secreting surface, and produces its effects there, that is, an ulcer, the parts so affected are capable of continuing the disease, or this mode of action, for ever, as will be taken notice of when we shall hereafter consider chancre. But this difference between spontaneous and non-spontaneous cure seems to depend more on the difference in the two modes of action than on the difference in the two surfaces ; for when the disease produces an ulcer on a secreting surface, which it often does from the constitution, as on the tonsils, it has no disposition to cure of itself; nor in the urethra, if ulcers are formed there, would they heal more readily than when formed in any other part. The common practice proves these facts; we every day see gonorrhoeas cured by the most ignorant; but in chancre, or the lues venerea, more skill is necessary. The reason is obvious: gonorrhoea cures itself, whilst the other forms of the disease require the assistance of art. It sometimes happens that the parts which become irritated first get well, while another part of the same surface receives the irritation, which continues the disease, as happens when it shifts from the glans to the urethra. From this circumstance of all gonorrhoeas ceasing without medical help, I should doubt very much the possibility of a person getting a fresh gonorrhoea while he has that disease, or of his increasing the same by the application of fresh matter of its own kind. And this observation holds in all the forms of the disease; for it has been proved that the application of the matter from a gonorrhoea to a bubo does not in the least retard the cure of that bubo: nor does the matter of a chancre applied to a bubo, nor the matter of a bubo applied to a chancre, produce any bad effect; though if venereal matter is applied to a common sore it will often produce the venereal irritation. By all which I am led to believe that the venereal matter formed in a gonorrhoea does not assist in keeping up that gonorrhoea ; for it is only an application of matter, the poison and effects of which are exactly similar to the effects upon the solids already produced ; and that nothing could increase or continue the effect but something that is capable of increasing the disposition of the parts themselves to such inflammation, or of making them more susceptible of it. We find, besides, that a gonorrhoea may be cured while there is a chancre, and vice versa: now if fresh venereal matter were capable of keeping up the disease, no gonorrhoea could ever get well while there is this supply of venereal matter.* From all this it is reasonable to suppose that

* When treating of pus, in my lectures, I observed that I was inclined to believe that no matter, of whatever kind, can produce any effect upon the part that OF GONORRHOEA. 43 such a surface of an animal body is not capable of being irritated by its own matter : nor is it capable of being irritated beyond a certain time ; and therefore if fresh venereal matter were continued to be applied to the urethra of a man having a gonorrhoea, that it would go off just as soon as if no such application had been made, and get as soon well as if great pains had been taken to wash its own matter away. The same reasoning holds good in chancres. I carry this idea still further, and assert that the parts become less susceptible of the venereal irritation ; and that not only a gonorrhoea cannot be continued by the application of either its own or fresh matter, but that a man cannot get a fresh gonorrhoea, or a chancre, if he applies fresh venereal matter to the parts when the cure is nearly completed, and continues the application ever after, or at least at such intervals as are within the effect of habit. I can conceive that in time the parts may become so habituated to this application as to be insensible of it; for by a constant application the parts would never be allowred to forget this irritation, or rather never become unaccustomed to it; and therefore this supply of fresh matter could not affect the parts so as to renew the disease till they first recovered their original and natural state, and then they would be capable of being affected again. This opinion is not derived from theory only, but is founded on experience and observation. A man, immediately after having suffered a gonorrhoea, shall have frequent connexions with women of the town, and that for years successively, without being infected; yet a fresh man shall contract it immediately from the very same woman: and if the first-mentioned man were to be out of the habit of this irritation for some time, he then would be as easily infected as the other. Where this habit is not so strong as to prevent altogether the parts from being affected, still it will do it in part; and it is a strong proof of this that most people have their first gonorrhoea the most severe, and the succeeding ones generally become milder and milder, till the danger of infection almost vanishes. This seems to be explained by the following facts. A married man, who had had a communication with his wife only for several years, slept with a woman with whom he had formerly cohabited. She gave him a severe gonorrhoea, and declared that she was not conscious of being diseased. He put himself and her under my care; and while they were going on with their cures they still continued their intercourse, which I readily allowed. He got well,

formed it: nor do I believe that the matter of any sore, let it be what it will, ever does or can do any hurt to that sore; for the parts which formed the matter are of the same nature, and cannot be irritated by that which they produced, except extraneous matter is joined with it. The gland which forms the poison of the viper, and the duct which conveys it to the tooth, are not irritated by the poison ; and it would appear from Abbe Fontana's experiments that the viper cannot be affected by its own poison. Vide Traite sur le Venin de la Vipere, par M. F. Fontana, vol. i. p. 22. If what I have now advanced is true, wiping or washing away matter, under the idea of keeping the parts clean, is in every case absurd, 44 HUNTER ON THE VENEREAL DISEASE. and it was supposed she got well also. The intercourse was continued between them for many months after, without any mischief received on his side, or any suspicion of remaining disease on hers. At last this connexion was broken off; and she formed another attachment. She no sooner formed this new attachment than she gave her new lover a gonorrhoea; she now flew to me for a cure, and declared that she had no connexion but with the two gentlemen before mentioned, and therefore that the present disease must be the same for which I had attended her formerly. Her second lover was not a patient of mine: but I gave her medicines, which she very much neglected to take. Her lover continued his connexion, as the first had done, for several months after he had got well, without any further infection from her. But, unfortunately, her first lover returned about a twelvemonth after; and thinking himself secure, as she lived in peace with the present, renewed his acquaintance with her, and but once ; the consequence, however, was a gonorrhoea. Had the woman the gonorrhoea all this time ? And what was the reason why those gentlemen did not catch the disease, except after that the acquaintance had been interrupted for some time 1 Was it the effect of habit, by which the parts lost their susceptibility of that irritation? The case of a young woman from the Magdalen Hospital is a striking proof of this, as far as circumstances can prove a fact. She was received into that house, and continued the usual time, which is two years. The moment she came out she was picked up by one who was waiting for her with a post-chaise to carry her off immediately. She gave him a gonorrhoea. This opinion of parts being so habituated to this irritation as hardly to be affected by it is strengthened by observing that in the gonorrhoea the violent symptoms shall often cease, and the disease shall still continue, spinning itself out to an amazing length, with no other symptoms than a discharge; yet that discharge shall be venereal, This I have frequently seen ; and the following is an abstract of a singular case of this kind. A gentleman had connexion with a woman of the town, and received a venereal gonorrhoea in the beginning of April 1780. He at first could hardly believe it to be venereal, as he had kept the woman in the country, where she had scarcely ever been out of his sight; but the violent pain in making water, great running, chordee, and swelled testicle convinced him that it was venereal. When the cure was going on tolerably well, and he had got the better of one swelled testicle, the other began to swell; however, all the symptoms gradually disappeared, except the chordee, hardness of the epididymis, and a small gleet which was slimy. On the 12th of June he went into the country: while he was in the country the chordee went off, and the hardness of the epididymis entirely disappeared ; but still a slimy gleet remained, although but trifling. ° OF GONORRHOEA. 45 September the first, he married a young lady, and endeavouring to enter the vagina, he found great difficulty, which brought on a return of the chordee, and an increased discharge. On the 10th, she began to complain of heat and pain, and of a difficulty and frequency in making water; and when she made water there was forced out some matter; she had also a dull heavy pain, and a sense of weight at the bottom of her belly and round her hips, with great soreness of the parts when she sat. These symptoms had been preceded by an itching about the orifice of the vagina. By taking a mercurial pill, and rubbing the parts with mercurial ointment, in about eight days the violence of the symptoms abated. They were now allowed to cohabit; but whenever they came together the pain which she suffered was excessive. The parts were washed with a solution of corrosive sublimate and sugar of lead, and anointed with mercurial ointment, which applications being continued for some time, the soreness went off. He was treated medically, and afterwards all was well. Here was a venereal gonorrhoea contracted about the beginning of April; all the symptoms had disappeared by the first of June, and there only remained some of the consequences, such as chordee, hardness of the epididymis, and a discharge of a little slimy mucus, which could only be observed in the morning. In a short time the chordee and hardness in the epididymis had entirely gone off, and merely the small discharge of mucus, which appeared only in the morning, remained; yet three months after he communicated the disease to his wife. I was consulted in the following case by the surgeon who attended. July 13th, 1783, a person had connexion with a woman of the town; the 30th, that is; seventeen days after, a gonorrhoea came on, which was violent. He took mercurial pills and gentle purges. In twelve days the violent symptoms abated, and about the 4th of September the discharge was stopped. On the 9th it began to appear again, but only lasted a few days; and would come and go in this way sometimes every two days, often six or seven days. On the 28th of September he had connexion with his wife, while he had a small discharge. The 9th of October he had connexion again; and three days after she complained of heat in making water, with a discharge and other symptoms of gonorrhoea, which were violent. About the latter end of October her complaints were almost removed, some only of the symptoms appearing and disappearing till January 1784, when he had connexion with her to try whether she could give it him, viz. three months after the second connexion; and in fourteen days after this he had all the symptoms of a gonorrhoea. April 29, he was not perfectly well, having a discharge, with a pain in the perinaeum; and she also had a discharge. If this last attack, in January 1784, in him was a gonorrhoea, then of course she must have had it; and also of course he must have lost his in the intermediate time, between 5* 46 HUNTER ON THE VENEREAL DISEASE. the 9th of October 1783 and January 1784; for if he had it also then, it could not have produced any effect upon him. It was impossible to say whether they had now the infection or not, for any trials upon themselves would prove but little, except one of them only had it so as to infect the other; but if both had it, no alteration could take place in either, as it could not be ascertained whether they had the disease or not; and as there were suspicious symptoms in both, when joined with all the circumstances, I agreed, with the attending surgeon, that it was most prudent to treat them as if actually affected with a gonorrhoea. If it is true, as is inserted in the Voyage round the World, that the venereal disease was carried to Otaheite, it shows that it can be long retained after all ideas of its existence have ceased; and when it is retained for such a length of time it is most probably in the form of gonorrhoea.* In like manner, a venereal bubo, if it could be kept a considerable time between the point of suppuration and resolution, would become indolent from habit, continue in that point of suspension, and remain perhaps almost incurable. Such, I think, I have seen.

§ 4. Of the Venereal Gonorrhoea.

In treating of the seat, extent, and symptoms of gonorrhoea, I shall begin with such particulars as are constant or most frequent, and take them as much as possible in the order they become less so; for there is a considerable variety in different gonorrhoeas.

§ 5. Of the Seat of the Disease in both Sexes.

The seat of this disease, in both sexes, is commonly the parts of generation. In men it is generally the urethra, though it sometimes takes place on the inside of the prepuce and surface of the glans. In women it is the vagina, urethra, labia, clitoris, or nymphae. The disease has its seat in these parts from the manner in which it is caught. But if we were to consider the surface of contact simply in men, we should naturally suppose that the glans penis,f or the orifice of the urethra, would be the first, or indeed the only parts affected; yet most commonly they are not, for though there are cases where the glans is affected, and where the disease goes no further, I believe it seldom attacks the orifice of the urethra without passing some way along that canal. How far it ever can be said to affect the prepuce only lam not quite certain, although I believe it sometimes happens; for 1 have seen inflammation there, as well with as without a discharge from the urethra, which appeared to me to be venereal. I have seen in such cases the inflammation extending into the loose cellular membrane of the

* Vide page 24. j Inserted : " inner surface of the prepuce, near to the glans."—Home. OF GONORRHOEA. 47 prepuce, and producing a phimosis; and this inflammation I suspect to be of the erysipelatous kind. When the disease attacks the glans and other external parts, as, for instance, the prepuce,* it is principally about the root of that body and the beginning of the prepuce, the parts where the cuticle is thinnest, and of course where the poison most readily affects the cutis; but sometimes it extends over all the glans, and also the whole external surface of the prepuce. It produces there a soreness or tenderness, with a secretion of thinnish matter, commonly without either excoriation or ulceration. I am not certain, however, that it does not sometimes excoriate those parts, for I once saw a case where almost the whole cuticle was separated from the glans. The patient assured me that it was venereal, and from the particular circumstances which he related, I had no reason to think his opinion ill founded. He never had had any such complaint from connexion with women before that time. Perhaps the disease begins oftener on those parts than is commonly imagined, but being defended by a cuticle, they are but little susceptible of this kind of irritation; and this may be the reason why a permanent effect is not produced, and why it is often so slight as not to be observed. "When the glans or prepuce, or both, suffer the venereal inflammation, it often rests there, and goes no further, not being attended with a dischare of matter, nor with pain in the urethra. This the following case illustrates. A young gentleman from Ireland slept with a woman at Bristol, and a fortnight afterwards he had intercourse with another woman in London, which last happened to be on a Monday, and on the Tuesday, or the day following, he observed a discharge from the end of his penis when covered with the prepuce. On the Saturday following he applied to me. Upon examination, I found that the running came from the inside of the prepuce, near to the glans; and the corona glandis, as also that part of the prepuce which is behind it, appeared to be in a tender and excoriated state, and covered with matter. He told me he had once had a gonorrhoea before, and upon being asked if it was in the same place, he said it was. Not being certain how far this might be venereal, I made the following inquiry: whether he had been subject to such excoriations before he had visited women 1 And his answer was, that he never had ; and that he had not this complaint always after coition, but only twice, as has been above mentioned, which, being uncommon, inclined him to suppose the effect to be venereal. I suspect that when the prepuce swells in a gonorrhoea of the urethra, producing a phimosis, which is often the case, it arises from the same disease having affected its inside, and that not being sufficient to produce ulceration, it goes no further. It seems probable that this inflammation is of the erysipelatous kind, a circumstance very necessary to be known in the cure. * Inserted : "I believe it is principally in those patients whose glans is commonly covered with the prepuce, and—."—Home. 48 HUNTER ON THE VENEREAL DISEASE. The urethra is the part in which this form of the venereal disease is most frequent; and although the inflammation attending the disease in this part has many of the common symptoms of inflammation, yet it can hardly be called inflammatory when moderate, at least it does not constantly produce all the effects of common inflammation, though there is a tendency towards it. The parts seldom have all the characteristic symptoms; for there is no throbbing sensation ; there is but little pain, except from the irritation of the urine and distention of the parts ; the inflammation seldom goes deeper than the surface, and we have therefore rarely any tumefaction or thickening of the parts. It should rather seem to be an error loci on the surface of the urethra, like a bloodshot eye. The secretion of pus with so little inflammation is perhaps owing to these parts being naturally in a state of secretion; therefore the transition from a healthy to a diseased secretion is more easily produced. It sometimes happens, however, that the parts do inflame considerably, and the inflammation goes deep into the cellular, or rather reticular, membrane of the corpus spongiosum urethrae, especially near the glans. Sometimes it extends further along the corpus spongiosum urethrae, producing tumefaction, that is, an extravasation of the coagulable lymph, which is the common cause of chordee. It may be observed in general, that in most cases when suppuration is produced there is a decrease of inflammation. The inflammation in the reticular membrane of the surrounding parts would appear not to be always confined to the adhesive stage, for in those parts we have sometimes suppurations, especially in the perinaeum, which suppurations I suspect to be in the glands, as will be taken notice of hereafter. The gonorrhoea does not always attack an urethra otherwise sound; nor does it always attack an urethra the relative parts of which are always sound. Thus we find people contracting this disease while they are affected with strictures, a swelled prostate gland, as also diseased testicles, or such testicles as very readily run into disease, by which the malady becomes more complicated, and requires more attention in the method of cure. Sometimes such diseases are relieved by the gonorrhoea, at other times increased.

§ 6. Of the most common Symptoms, and the Order of their Appearance.

Although the irritations must always begin first, yet it is not certain which of the symptoms, in consequence of that irritation, will first appear, for any one may appear singly without the others, though this is rarely the case. The first symptom, when carefully attended to, is generally an itching at the orifice of the urethra, sometimes extending over the whole glans ;* a little fulness of the * These symptoms are most carefully observed by those who are under apprehensions of having the disease, and therefore are attentive to every little sensation about those parts. OF GONORRHOEA. 49 lips of the urethra: the effects of inflammation are next observable, and soon after a running appears ; the itching changes into pain, more particularly at the time of voiding the urine; there is often no pain till some time after the appearance of the discharge, and other symptoms; and in many gonorrhoeas there is hardly any pain at all, even when the discharge is very considerable ; at other times the pain, or rather a great degree of soreness, will come on long before any discharge appears.* There is generally at this time a greater fulness in the penis, and more especially in the glans, although it is not near so full as when erected, being rather in a state of half-erection. Besides this fulness, the glans has a kind of transparency, especially near the beginning of the urethra, where the skin is distended, being smooth and red, resembling a ripe cherry, this is owing to the reticular membrane, at this time loaded with a quantity of extravasated serum, and the vessels filled with blood. Near the beginning of the urethra there is in many cases an evident excoriation, which is marked by the termination of the cuticle all around. The surface of the glans also is often in a half-excoriated state, which gives it a degree of tenderness, and there oozes out from it a kind of matter, as has been before observed.f The canal of the urethra becomes narrower, which is known by the stream of the urine being smaller than common. This proceeds from the fulness of the penis in general, and from the internal membrane of the urethra being swollen by the inflammation, and also from its being in a spasmodic state. Besides these changes, the fear of the patient whilst voiding his urine assists in diminishing the stream of urine. The stream, as it flows from the urethra, is generally much scattered and broken as soon as it leaves the passage, which is owing to the internal canal having become irregular, and is not peculiar to a venereal gonorrhoea, but common to every disease of the urethra that alters the exact and natural figure of the canal, even although the irregularity is very far back. This we find in many diseased prostate glands.J There is frequently some degree of hemorrhage from the urethra. This I suppose arises from the distension of the vessels, more especially when there is a chordee, or a tendency to one. There are often small swellings observable along the lower surface of the penis in the course of the urethra. These, I suspect, are the glands of the urethra so enlarged as to be plainly felt on

* Added: " and extend a little way down the canal. I have known these sensations to be felt half way down the urethra."—Home. f Added : " but this is more evident in those whose glans penis is commonly covered by the prepuce, for when denuded the cuticle becomes thicker, and is less easily irritated."—Home. X Added: "In some instances the first symptoms are unusual sensations in the penis, especially while making water, which come on a few days after receiving the infection, attended with constitutional irritability, sensations in the testicles neck of the bladder, and anus ; these continue for about ten days, when a discharge comes on, and they disappear."—Home. 50 HUNTER ON THE VENEREAL DISEASE. the outside. They inflame so much in some cases as to suppurate, and, according to the laws of ulceration, the matter is brought to the skin, forming one, two, or more abscesses, along the under surface of the urethra: and some of these breaking internally, form what are called internal ulcers. I have observed in several cases a tumour on the under side of the penis, where the urethra is, which would swell at times very considerably, even to the size of a small flattened nut, inflame, and then, a gush of matter flowing from the urethra, would almost immediately subside. The discharge has continued for some time, gradually diminishing till it has entirely gone off, and the tumour has been almost wholly reduced ; yet after some months it has swelled in the same manner again, and terminated in the same way. How far these tumours, and the matter they discharge, are really venereal when they appear first, may be doubtful; and it is difficult to determine this, for the patients in general have recourse to medicine immediately; but in their subsequent attacks they are certainly not venereal, for they cure themselves. I have suspected these tumours to be the ducts or lacunae of the glands of the urethra, distended with mucus, from the mouth of the duct being closed, in a manner similar to what happens to the duct leading from the lachrymal sac to the nose; and in consequence of the distention of the ducts or lacunae, inflammation and suppuration come on, and ulceration takes place, which opens a way into the urethra ; but this opening soon closes up and occasions a return. Cowper's glands have been suspected to inflame, and hardness and swelling have been felt externally very much in the situation of them, which, coming to suppuration, have produced considerable abscesses in the perinaeum. These tumours break either internally or externally, and sometimes in both ways, making a new passage for the urine, called fistulae perinaeo. A soreness is often felt by the patient all along the under side of the penis, owing to the inflamed state of the urethra. This soreness often extends as far as the anus, and gives great pain, principally in erections; yet it is different from a chordee, the penis remaining straight. Erections are frequent in most gonorrhoeas. These, arising from the irritation at the time, often approach to a priapism, especially when there is the above-mentioned soreness, or when there is a chordee. Priapisms often threaten mortification in men; and I have seen an instance of it in a dog. The erection never subsided, and the glans penis could not be covered by the prepuce, from the swelling of the bulb. The penis mortified and dropped off; the bone in it was denuded, and an exfoliation followed. As opium is of great service in priapism, there is reason to suppose the complaint is of a spasmodic nature. OF GONORRHOEA. 51 § 7. Of the Discharge.

The natural slimy discharge from the glands of the urethra is first changed from a fine transparent ropy secretion to a watery, whitish fluid ; and the natural exhaling fluid of the urethra, which is intended for moistening its surface, and which appears to be of the same kind with that which lubricates cavities in general, becomes less transparent; and both' these secretions becoming gradually thicker, assume more and more the qualities of common pus. In some cases of gonorrhoea, the glands that produce the slime which is secreted in consequence of lascivious ideas, are certainly not affected ; for I have seen cases, when, after the passages had been cleared of the venereal matter by making water, the pure slime has flowed out of the end of the penis on such occasions.— When this matter is more in quantity than what lubricates the urethra, it is forced out of the orifice by the peristaltic action of that canal, and appears externally.* The matter of gonorrhoea often changes its colour and consistence, which is owing to the disposition of the parts which form it; sometimes from a white to a yellow, and often to a greenish colour.— These changes depend on the increase or decrease of the inflammation, and not on the poisonous quality of the matter itself; for any irritation on these parts, equal to that produced in a gonorrhoea, will produce the same appearances; and the changes in the colour of the matter are chiefly observable after it has been discharged upon a cloth and become dry. The appearance upon the cloth is of various hues: in the middle the matter is thicker or more in quantity, and it is therefore generally of a deeper colour ; the circumference is paler, because the watery or serous part of the matter has spread further; and at the outer edge of all it is darkest; this last appearance is owing to its being only water with a little slime, in which some of the tinge is suspended, which when dry gives a transparency to the part that takes off from the white colour of the linen. It is very probable that there is a small extravasation of red blood in all the cases where the matter deviates from the common colour, and to this the different tinges seem to be owing. As this matter arises from a specific inflammation, it has a greater tendency to putrefaction than common matter from a healthy sore, and has often a smell seemingly peculiar to itself. As it should appear that there is hardly a sufficient surface of the urethra inflamed to give the quantity of matter that is often produced, especially when we consider that the inflammation does in common go no further than two or three inches from the external orifice, it is natural to suppose that the discharge is produced from other parts, the office of which is to form mucus for natural purposes, and * That the urethra has considerable powers of action is evident in avast number of instances ; and that action is principally from behind forwards. We find that a bougie may be worked out by the action of the urethra. This action, I believe, is often inverted, as in spasmodic stranguries. 52 HUNTER ON THE VENEREAL DISEASE. which are therefore more capable of producing a great quantity upon slight irritations, which hardly rise to inflammation. These parts, I have observed, are the glands of the urethra. In many cases where the glands have not been after death so much swelled as to be felt externally, and where I have had an opportunity of examining the urethra of those who have had this complaint upon them, I have always been able to discover that the ducts or lacunae leading from them have been loaded with matter, and more visible than in the natural state. I have observed too that the formation of the matter is not confined to these glands entirely; for the inner surface of the urethra is commonly in such a state as not to suffer the urine to pass without considerable pain, and therefore most probably this internal membrane is also affected in such a manner as to secrete a matter. This discharge, in common cases, should seem not to arise much further back in the urethra than where the pain is felt, although it is commonly believed that it comes from the whole of the canal, and even from Cowper's glands and the prostate, and even what are called the vesiculae seminales.* But the truth of this I very much doubt. My reason for supposing that it comes only from the surface where the pain is, are the following. If the matter arose from the whole surface of the urethra and from the glands near the bladder, there would certainly be many other symptoms than do actually occur: for instance, if all the parts of the urethra beyond the bulb, or even in the bulb, were affected so as to secrete matter, that matter would be gradually squeezed into the bulb as the semen is, and from thence it would be thrown out by jerks; for we know that nothing can be in the bulbous part of the urethra without stimulating it to action, especially when in a state of irritation and inflammation. In such a state we find that even a drop of urine is not allowed to rest there ; and also if an injection of warm water only is thrown into the urethra as far as the bulb, the musculi accelerators are uneasy till they act, and throw it out. Hence it is natural to suppose, that if the membranous and bulbous part of the urethra, with the vesiculae seminales, prostate, and Cowper's glands, assisted in forming the matter, whenever it collected in the bulb it would probably be immediately thrown forwards by the muscles above mentioned, and we should be sensible of it every moment of the day. But such symptoms are seldom observed. Sometimes indeed a spasmodic contraction of these muscles occurs, which may probably arise from this cause, though it is more frequently felt immediately after the urine is discharged. When the inflammation is violent, it often happens that some of the vessels of the urethra burst, and a discharge of blood ensues, which is in greater quantity at the close of voiding urine. This,

* Those bags are certainly not reservoirs for the semen. The difference between the contents of them and the semen gave me the first suspicion of this; and from several experiments on the human body, as also a comparative view of them in other animals, I have been able to prove that they are not. OF GONORRHOEA. 53 however, happens at other times, and generally gives temporary ease. Sometimes this blood is in small quantity, and only gives the matter a tinge ; as I observed when treating of the colour of the discharge. The erections of the penis often stretch the part so much as to become a cause of an extravasation of blood. This extravasation generally increases the soreness at the time of emptying the bladder, and in such a state of parts the urethra is usually sore when pressed; yet the bleeding diminishes the inflammation, and often gives ease.

• The chordee appears to be inflammatory in some cases, and spasmodic in others. We shall treat first of the inflammatory chordee. When the inflammation is not confined merely to the surface of the urethra and its glands, but goes deeper and affects the reticular membrane, it produces in it an extravasation of coagulable lymph, as in the adhesive inflammation, which uniting the cells together, destroys the power of distention of the corpus spongiosum urethrae, and makes it unequal in this respect to the corpora cavernosa penis, and therefore a curvature takes place in the time of erection, which is called a chordee. The curvature is generally in the lower part of the penis, arising from the cells of the corpus spongiosum urethrae having their sides united by adhesions.* Besides this effect of inflammation, when the chordee is violent, the inner membrane is, I suppose, so much upon the stretch, as to be in some degree torn, which frequently causes a profuse bleeding from the urethra, that often relieves the patient, and even sometimes proves the cure. As chordee arises from a greater degree of inflammation than common, it is an effect which may, and often does, remain when all infection is gone, being merely a consequence of the adhesive inflammation.

§ 9. Of the Manner in which the Inflammation attacks the Urethra.

In what manner the disease extends itself to the urethra is a question not yet absolutely determined. I suspect that it is communicated or creeps along from the glans to the urethra, or at least from the beginning or lips of the urethra to its inner surface; because it is impossible to conceive that any of the venereal matter from the woman can get into the canal during coition, although the contrary is commonly asserted. It is impossible, at least, that it can get so far as the common seat of the disease, or into those parts of the urethra where it very often exists, that is, through the whole length of the canal. The following case amounts almost to a proof of this opinion.

* The preceding sentence omitted.—Home. 6 54 HUNTER ON THE VENEREAL DISEASE. A gentleman, on whose veracity I have an entire confidence, when in Germany, where he had not lain with a woman for many weeks, sat in a necessary-house some time. Upon arising, he found something that seemed to give the glans penis a little sharp pull, and he found a small bit of the plaster of the necessary-house sticking to it. He paid no further attention to it at that time than merely to remove what stuck to his penis; but five or six days after, he observed the symptoms of a clap, which proved a pretty severe one. The only way of accounting for this is, that some person who had a clap had been there before him, and had left some venereal matter upon this place, and that the penis had remained in contact with it a sufficient time for the matter to dry. When the disease attacks the urethra it seldom extends further than an inch and a half, or two inches at most, within the orifice, which distance appears to be truly specific, and what I have called the specific extent of the inflammation.* As the cause of a gonorrhoea is commonly an inflammation, it is accompanied with pain and the formation of matter. In such a state neither the sensations of the patient nor the actions of the parts themselves are confined to the real seat of the disease. In consequence of the neighbouring parts sympathising, a variety of symptoms are produced, many of which do not exceed what might arise from an irritable stale. An uneasiness partaking of soreness and pain, and a kind of weariness, are everywhere felt about the pelvis ; the scrotum, testicles, perinaeum, and hips become disagreeably sensible to the patient, and the testicles often require being suspended ; and so irritable are they indeed in such cases, that the least accident or even exercise, which would have no such effect at another time, will make them swell. The glands of the groin are often affected sympathetically, and even swell a little, but do not come to suppuration. When they inflame from the absorption of matter, they in general suppurate". I have seen cases where the irritation has extended so far as to affect with real pain the thighs, the buttocks, and the abdominal muscles, so that the patient has been obliged to lie quiet in a horizontal position. The pain has at times been very acute, and the parts have been very sore to the touch ; they have even swelled, but the swelling has not been of the inflammatory kind; for notwithstanding a visible fulness, the parts have been rather soft. I knew one gentleman who never had a gonorrhoea but that he was immediately seized universally with rheumatic pains: this had happened to him several times. The blood at such times is generally free from the inflammatory appearance, and therefore we may suppose that the constitution is but little affected.

* It is to be here remarked, that specific diseases, among which I shall reckon such as arise from morbid poisons, have their specific distance or extent as one ot their properties ; but this can only take place where the constitution is not susceptible of erysipelas, or any other uncommon mode of action ; for where there is an erysipelatous disposition no bounds are set to the inflammation OF GONORRHOEA. 55 When the gonorrhoea (exclusive of the affections arising from sympathy) is not more violent than I have described, it may be called common or simple venereal gonorrhoea; but if the patient is very susceptible of such irritation, or of any other mode of action which may accompany the venereal, then the symptoms are in proportion more violent. In such circumstances we sometimes find the irritation and inflammation exceed the specific distance, and extend through the whole of the urethra. There is often also a considerable degree of pain in the perinaeum ; and a frequent though not a constant symptom is a spasmodic contraction of the acceleratores urinae, which is always attended with contractions of the erectores muscles. Whether these spasms arise from a secretion of matter, which being collected in the bulbous part of the urethra produces uneasiness, and excites contractions in order to its own expulsion, like the last drops of urine, I have not been able to determine. I have seen such spasms in the time of making water, from the urine irritating the parts in its passage through the urethra, and throwing the musculi acceleratores into contractions, so that the water has come by jerks. This kind of inflammation sometimes is considerable, goes deep into the cellular membrane, and produces tumefactions without any other effect.* In other cases it goes on to suppuration, often becoming one of the causes of fistulae in perinaeo. I have sometimes, as I have already observed, suspected Cowper's glands to be the seat of such suppurations; for I have observed externally circumscribed swellings in the situation of those glands. The small glands likewise of the bulbous part of the urethra may be affected in a similar manner; and the irritation is often extended even to the bladder itself.f When the bladder is affected it becomes more susceptible of every kind of irritation, so that very disagreeable symptoms are often produced : it will not allow of the usual distention, and therefore the patient cannot retain his water the ordinary time; and the moment the desire of making water takes place, he is obliged instantly to make it, with violent pain in the bladder, and still more in the glans penis, exactly similar to what happens in a fit of the stone. If the bladder be not allowed to discharge its contents immediately, the pain becomes almost intolerable; and even when the water is evacuated, there remains for some time a considerable pain both in the bladder and glans, because the very contraction of the muscular coat of the bladder becomes a cause of pain. The ureters, and even the kidneys, sometimes sympathise, when the bladder is either very much inflamed, or under a considerable degree of irritation ; however, this but rarely happens. I have even

* Added : " There is often a pain in the urethra after making water, in the same part in which it is usually felt while the water passes; this I believe to be the effect of the contraction of the internal membranes, which lasts for some time after the action has ceased."—Home. f Added : " This happens more commonly towards the going off of the gonorrhoea."—Home. 56 HUNTER ON THE VENEREAL DISEASE.

reason to suspect that the irritation may be communicated to the peritonaeum by means of the vas deferens. This suspicion receives some confirmation from the following history. A gentleman had a gonorrhoea, which was treated in the antiphlogistic way. The discharge being in some degree stopped, a tension came upon the lower part of the belly on the right side, just above Poupart's ligament, but rather nearer to the ilium. There was hardness and soreness to the touch, which soreness spread over the whole belly, producing rigors every third day, with a low pulse, which to me indicated a peritonaea! inflammation, arising, in my opinion, from the vas deferens of that side being affected in its course through the belly and pelvis. When the inflammation, or perhaps only the irritation, runs along the whole surface of the urethra, attacks the bladder, and even extends to the ureters and the kidneys, so as to cause a disagreeable sensation in all these parts, the disease is generally very violent, and I suspect is something of the erysipelatous kind ; at least it shows an irritable sympathising habit. This disease sometimes produces very uncommon symptoms. A gentleman had a gonorrhoea ; and when the inflammatory symptoms were abating, the urethra lost both the involuntary and voluntary powers of retaining the urine. His water came away involuntarily, nor could he stop it. I advised him to do nothing, and to wait for some time, as probably the method of cure might be more disagreeable than the disease itself, although it was very troublesome to him when in company. The complaint gradually lessened, and in time went entirely off.

§ 10. Of the Swelled Testicle.

A very common symptom attending a gonorrhoea is a swelling of the testicle. This I believe, like the affection of the bladder, and many of the symptoms mentioned before, is only sympathetical, and not to be reckoned venereal, because the same symptoms follow every kind of irritation on the urethra, whether produced by strictures, injections, or bougies. It may be observed here, that those symptoms are not similar to the actions arising from the application of the true venereal matter, whether by absorption or otherwise, for they seldom or never suppurate; and when suppuration happens, the matter produced is not venereal. The testicles seem, as it were, in many cases, rather to be acting for the urethra than for themselves, which is an idea applicable to all sympathies. Thus the swelling and inflammation appear suddenly, and as suddenly disappear, or in a few minutes go from one testicle to the other ; the affection depending upon the state of the urethra, and not at all upon the part itself. A part, however, of the testicle, the epididymis, assumes all the characters of inflammation, remaining swelled even for a considerable time after the inflammation has subsided. OF GONORRHOEA. 57 The first appearance of swelling in the testicle is generally a soft pulpy fulness of the body of the testicle, which is tender to the touch; this increases to a hard swelling, accompanied with considerable pain. The hardest part is generally the epididymis, and principally that portion of it which is at the lower end of the testicle, as may be distinctly felt. The hardness and swelling, however, often run the whole length of that body, and form a knob at the upper part. The spermatic cord is likewise often affected, and more especially the vas deferens, which is thickened and sore to the touch. The veins of the testicle sometimes become varicose. I have seen such a state of veins accompany a swelling of the testicle in two instances. A pain in the small of the back generally attends inflammations of the testicle of all kinds, with a sense of weakness of the loins and pelvis. The bowels generally sympathise with most complaints of the testicle; in some by colicy pains, in others by an uncommon sensation both in the stomach and intestines. Sickness is a common symptom, and even vomiting; the powers of digestion by this means are impaired, and a disposition for the accumulation of air takes place, which is often very troublesome. Here we have from the testicles a chain of sympathies, as we had in consequence of the irritation running along the whole urinary passages : first the testicle is affected from the urethra ; then the spermatic cord, the loins, intestines, stomach; and from thence in some measure the whole body. In a case of swelled testicle, I have known the buttocks swell; but the swelling was not of the inflammatory kind, and in making water pain was felt in that part. Whether this symptom arose from the swelling of the testicle, or from the same common cause, that is, the gonorrhoea, is not easily determined, although the latter supposition is the most probable. It has been asserted, but without proof, that in cases of swelled testicles in consequence of a gonorrhoea, it is not the testicle that swells, but the epididymis. The truth is, it is both the one and the other. Any man that is accustomed to distinguish between a swelling of the whole testicle, and that of the epididymis only, will immediatelv be sensible that in the hernia humoralis the whole testicle is "'swelled. The testicle assumes the same shape that it does from other causes, where we know, from being obliged to remove it, that the whole has swelled. The pain is in every part of the testicle. I have seen such swellings suppurate on the fore part, and have known several instances of adhesions between the tunica albuginea and vaginalis, from such causes. This has only been discovered after death, or in the operation for a partial hydrocele. Such changes could not have taken place if the body of the testicle had not been in a state of inflammation. This inflammation of the testicle most probably arises from its sympathising with the urethra, and in many cases it would appear to arise from what is understood by a translation of the irritation from the urethra to the testicle. Thus a swelling of the testicle coming on shall remove 58 HUNTER ON THE VENEREAL DISEASE. the pain in making water, and suspend the discharge, which shall not return till the swelling of the testicle begin to subside; or the irritation in the urethra first ceasing shall produce a swelling of the testicle, which shall continue till the pain and discharge return, thus rendering it doubtful which is the cause and which the effect. I have nevertheless known cases where the testicle has swelled and yet the discharge has become more violent; nay, I have'seen instances where a swelling has come on after the discharge has ceased, yet the discharge has returned with violence, and remained as long as the swelling of the testicle. Sometimes the epididymis only is affected, sometimes the vas deferens, and at other times only the spermatic cord, producing varicose veins. No reason can be assigned why one of these parts is affected more than another, and indeed the immediate cause in all is as yet unknown; for although an action in the urethra is the remote cause, yet it is still impossible to say whether it be the cessation of that action that is the cause of the swelling in the testicle, or the swelling in the testicle the cause of the cessation. It is described as arising from an irritation taking place in the mouths of the vasa deferentia. Were this the cause, it ought in general to affect both testicles at the same time : but I have seen this complaint happen as often where the inflammation has gone no further back in the urethra than about an inch and a half or twro inches, as where it has extended further ; and the circumstance of the swelling shifting suddenly from one testicle to the other shows it to arise from some other principle in the animal economy. A strangury often attends such cases of sympathy, and more frequently when the running stops, than when it is continued along with the swelling of the testicle. Indeed any sudden stoppage of the discharge gives a tendency to a strangury.* As singular a circumstance as any respecting the swelling of the testicle is, that it does not always come on when the inflammation in the urethra is at the height. I think it oftener happens when the irritation in the urethra is going off, and sometimes even after it has entirely ceased, and when the patient conceives himself to be quite well. I may be allowed to remark, that swellings in the testicle in consequence of venereal irritation in the urethra subject it to a suspicion that every swelling of this part is venereal; but from what I have said of its nature when it arises from a venereal cause, which was, that it is owing to sympathy only, and from what I shall now say, that it is never affected with the venereal disease, either local or constitutional, as far as my observation goes, it is to be inferred that such suspicions are always ill founded. This, perhaps, is an inference to which few will subscribe.f

* Added : " When the testicle is swelled, blood comes away with the semen ; this may either be thrown out in the act of secretion, or come from the bloodvessels of the urethra in the act of emission."__Home. f [This assertion is contradicted by experience. There is an affection of the OF GONORRHOEA. 59 I have known the gout produce a swelling in the testicle of the inflammatory kind, and therefore similar to the sympathetic swelling from a venereal cause, having many of its characters. Injuries done to the testicle produce swellings; but they are different from those above mentioned, being more permanent, having the disease or cause in the part itself. Cancers and the scrofula produce swellings of the testicle; but these are generally slow in their progress, and not at all similar to those arising from an irritation in the urethra.

§ 11. Of the Swellings of the Glands from Sympathy.

Since our knowledge of the manner in which substances get into the circulation, and our having learned that many substances, especially poisons, in their course to the circulation, irritate the absorbent glands to inflammation and tumefaction, we might naturally suppose such swellings, accompanying complaints in the urethra attended with a discharge, to be owing to the absorption of that matter, and therefore, if it be a venereal discharge, that they must also be venereal. But we must not be too hasty in drawing this conclusion, for we know that the glands will sometimes swell from an irritation at the origin of the lymphatics, where no absorption could possibly have taken place. They often swell and become painful upon the commencement of inflammation, before any suppuration has taken place, and subside upon the coming on of suppuration, because when the suppuration begins, the inflammation abates. I have known a prick in the finger with a clean sewing-needle produce a red streak all up the fore arm, pain along the inside of the biceps muscle, a swelling of the lymphatic gland above the inner condyle of the humerus, and also of the glands of the arm-pit, immediately followed by sickness and a rigor, all which, however, have soon gone off. As it should therefore appear that the absorbent system is capable of being affected as wel! by irritation as by the absorption of matter, in all diseases of this system arising from local injuries attended with matter, one must always have these two causes in view, and endeavour, if possible, to distinguish from which the present affection proceeds. For in those arising from an irritated surface in consequence of poison, especially the venereal, it is of considerable consequence to be able to say from which of the two it arises, since it sometimes happens, although but seldom, that the glands of the groin are affected in a common gonorrhoea with the appearance of beginning buboes, but which I suspect to be similar to the swelling of the testicle, that is, merely sympathetic. The pain they give is but very trifling, when compared to that of the true venereal swellings arising from the absorption of matter, and they seldom suppurate. However, there are swellings testicle which occurs so often in combination with venereal symptoms that it must be allowed to be a constitutional effect of the virus. It will be described hereafter among the secondary symptoms of lues venerea.] 60 HUNTER ON THE VENEREAL DISEASE. of these glands from actual absorption of matter in gonorrhoea, and which consequently are truly venereal; and as it is possible to have such, they are always to be suspected. As they have sometimes arisen upon a cessation of the irritation in the urethra, similar to the swelling of the testicle, it has been supposed that the matter was driven, as it were, into them by unskilful treatment. From our acquaintance with the absorbing system we know that the matter can go that way; but we also know that we have no method of driving it that way; and if we had, there is no reason why more should not be formed in the urethra. This therefore does not account for the cessation of secretion of matter in that part. It is difficult to say what is the nature of those sympathetic diseases. They are not venereal, for they subside by the common treatment of inflammation, without the use of mercury ; and I have known an instance of a swelled testicle from a venereal gonorrhoea that suppurated, and was treated by my advice as a common suppuration, and healed without a grain of mercury being given. Neither can they be called truly inflammatory, having rarely any of the true characters of inflammation, such as thickening of the parts, symptomatic fever, or sizy blood, except in swellings of the testicle and glands. The swelling of the testicle has several peculiarities attending it; it is often very quick in its increase, and not being of the true inflammatory disposition, it requires less tim for the removal of the inflammation ; but even where it appears to have more of the true inflammatory action, we find that the removal of the inflammation and tumefaction takes place more rapidly than when proceeding from other causes. A swelled testicle in consequence of the radical cure of the hydrocele does not subside after inflammation is gone, in as many weeks, as the swelled testicle in consequence of its sympathy with other parts, does in days; and probably the reason of this is, that it arises from sympathy for an inflammation arising from real disease in a part, or from an external injury, as in the hydrocele, must always last either till the disease be removed, or the injury repaired ; but that from sympathy will vary as the cause varies, which may happen very quickly, for we find a testicle swell in a few minutes, and in as little time subside ; and also the swelling move suddenly from one testicle to the other. These sympathies are often peculiar to constitutions, and even to temporary constitutions, in so much as to be in some degree epidemic, for there is often such an influence in the atmosphere as predisposes the body to this kind of irritation, and bodies so predisposed require only the immediate cause to produce the effect.

§ 12. Of the Diseases of the Lymphatics in a Gonorrhoea.

Another symptom, which sometimes takes place in gonorrhoea, is a hard cord leading from the prepuce along the back of the penis, and often directing its course to one of the groins, and affect- OF GONORRHOEA. 61 ing the glands. There is most commonly a swelling in the prepuce at the part where the cord takes its rise. This happens sometimes when there is an excoriation and discharge from the prepuce or glans which may be called a venereal gonorrhoea of these parts. Both the swelling in the groin, and the hard cord, we have reason to suppose, arise from the absorption of pus, and therefore that they are the first step towards a lues venerea ; but as that form of the disease seldom happens from a gonorrhoea, I shall not take any further notice of it in this place. However, I may remark, that from this observation of the lues venerea being seldom produced from a gonorrhoea, it should appear that a whole surface, or one only inflamed, does not readily admit of the absorption of the venereal poison; and therefore, although the venereal matter lies for many weeks in the passage, and over the whole glans, it seldom happens that any absorption takes place.* I have seen a case where blood has been discharged from the urethra, and the above mentioned symptoms have come on. I at first suspected that the absorption had taken place where the vessel gave way; but as this symptom rarely happens, even where there has been a considerable discharge of blood, I am inclined to think that wounds are also bad absorbing surfaces, especially when I consider that few morbid poisons are absorbed from wounds.

§ 13. Short recapitulation of the Varieties in the Symptoms.

From what has been advanced above, it must appear that the variety of symptoms in a gonorrhoea, and the difference of them in different cases, are almost endless. I shall now recapitulate a few of the most material or common varieties. The discharge often appears without any pain, and the coming on of the pain is not at any stated time after the appearance of the discharge. There is often no pain at all, although the discharge be considerable in quantity, and of a bad appearance. The pain often goes off, while the discharge continues, and will sometimes return again. An itching in some cases is felt for a considerable time, which sometimes is succeeded by pain, though in many cases it continues to the end of the disease. On the other hand, the pain is often troublesome, and considerable even when the discharge is trifling, or none at all. In general, the inflammation in the urethra does not extend beyond an inch or two from the orifice ; sometimes it runs all along the urethra to the bladder, and even to the kidneys ; and in some cases spreads in the substance of the urethra, producing a chordee. The glands

* Added : "Asa further proof that these cords often arise from an inflam matory excoriation and tumefaction of the prepuce, a gentleman had a chancre on the right side, at the root of the prepuce, close to the penis, besides which there was an excoriation of the penis everywhere, with a thickening of that part. Although the chancre was on the right side, and the excoriation principally on the left, yet there was a hard cord along the left side of the penis, leading to an enlarged gland in the groin."—Home. 62 HUNTER ON THE VENEREAL DISEASE. of the urethra inflame, and often suppurate; and I suspect that Cowper's glands sometimes do the same. The neighbouring parts sympathise, as the glands of the groin, the testicle, the loins, and pubes, with the upper parts of the thighs and abdominal muscles. Sometimes the disease appears soon after the application of the poison, as in a few hours, at other times not till after six weeks. It is often not possible to determine whether it is venereal, or only an accidental discharge arising from some unknown cause. It may not be improper to mention here, that I have seen a chancre on the prepuce produce a pain in the urethra in making water, which most probably depended upon a sympathy similar to that by which the application of venereal matter to the glans produces a discharge from the urethra, as was observed above. If the application of venereal matter to the glans can produce a discharge from the urethra, it is possible that any acrid matter, though not venereal, may have a similar effect. The discharge from the vagina, in cases of what is called fluor albus, is sometimes extremely irritating, in so much as to excoriate the labia and thighs; and the following history shows that it may sometimes produce effects similar to venereal matter. Mr. and Mrs.----have been married these twenty years and upwards. She has for many years past been at times troubled with the fluor albus. When he has connexion with her at such times, it has generally, although not always, produced an excoriation of the glans and prepuce, and a considerable discharge from the urethra, attended with a slight pain. These symptoms commonly take a considerable time before they go off, whether treated as a gonorrhoea or as a weakness. Is this a new poison ? And does it go no further because the connexion takes place only between two 1 What would be the consequence if she were to have connexion with other men, and these with other women ? Such cases, as far as I have seen, have only been in form of a gonorrhoea. They have not produced sores in the parts; nor, as far as I know, do they ever produce constitutional diseases. CHAPTER II.

OF THE GOPfORRHffiA Iff WOMEN.

The venereal disease in the form of a gonorrhoea in women is not so complicated as in men; the parts affected are more simple, and fewer in number. But it is not so easily known in them as it is in men, because the parts commonly affected in women are very subject to a disease resembling the gonorrhoea, called fluor albus; and the distinguishing marks, if there are any, have not yet been OF THE GONORRHOEA IN WOMEN. 63 completely ascertained. A discharge simply from these parts in women is less a proof of the existence of the venereal infection than even a discharge without pain in men ; therefore in general little or no attention is paid to it by the patient herself, and we often find the venereal virus formed in those parts without any increase of the natural discharge. The kind of matter gives us no assistance in distinguishing the two diseases, for it often happens that the discharge in the fluor albus puts on all the appearances of the venereal matter; and an increase of the discharge is no better mark by which we can distinguish the one from the other. Pain, or any peculiarity in the sensations of the parts, is not a necessary attendant upon this complaint in women, therefore not to be looked for as a distinguishing symptom. The appearance of the parts often gives us but little information, for I have frequently examined the parts of those who confessed all the symptoms, such as increase of discharge, pain in making water, soreness in walking, or when they were touched; yet I could see no difference between these and sound parts. I know of no other way of judging in cases where there are no symptoms sensible to the person herself, or where the patient has a mind to deny having any uncommon symptoms, but from the circumstances preceding the discharge, such as her having been connected with men supposed to be unsound, or her being able to give it to others, which last circumstance, being derived from the testimony of another person, is not always to be trusted to, for very obvious reasons. Thus a woman may have this species of the venereal disease without knowing it herself, or without the surgeon being able to discover it, even on inspection. It may appear very strange, that a disease which is so violent and well marked in men should be so obscure in women; but when we consider that this poison generally produces symptoms according to the nature of the parts affected by it, it becomes an easy matter to account in some measure for this difference. When we attend to the manner in which this disease is contracted by women, it is evident that it must principally attack the vagina, a part that is not endowed with much sensation, or action of any kind. While it is confined to the vagina it may be compared to the same disease on the glans penis in men. In many cases, however, it extends much further, and becomes the cause of disagreeable feelings, producing a considerable soreness in all the parts formed for sensation, such as the inside of the labia, nymphae, clitoris, carunculse myrtiformes, the orifice of the meatus urinarius, and often affecting that canal in its whole length. Those parts are so sore in some cases as not to bear being touched ; the person can hardly walk; the urine gives pain in its passage through the urethra, and when it washes the above-mentioned parts, which can hardly be avoided. Such symptoms are not much increased at one time more than another, excepting at the time of making water, 64 HUNTER ON THE VENEREAL DISEASE. and then principally in those who have the urethra affected, for as these parts are less exposed to circumstances of change, the increased irritation arising from such change of parts must necessarily in this sex be less. But in men the urethra, which is the part most commonly affected, has great sensibility, is capable of violent inflammation, is often distended with a stimulating fluid, and the body of the penis, urethra, and glans, stretching the passage with erections, always produce an increase of the symptoms, especially of the pain. But as this disease frequently attacks parts more sensible than the vagina, and which are more susceptible of inflammation, as has been observed, under such circumstances women have nearly the same symptoms as men; a fulness about the parts, almost like an inflamed tonsil, a discharge from the urethra, violent pain in making water, and great uneasiness in sitting, from pressure on those parts. The bladder sometimes sympathises, producing the same symptoms as in men, and it is probable that the irritation may be communicated even to the kidneys. It has been asserted that the ovaria are sometimes affected in a similar manner to the testicles in men. I have never seen a case of this kind, and I should very much doubt the possibility of its existence; for we have no instance, in other diseases, of the ovaria sympathising with those parts, or at least producing such symptoms as would enable us to determine that they did. That there do, however, uncommon symptoms now and then occur, should appear from the following case. A lady had all the symptoms of a venereal gonorrhoea, such as a discharge, pain and frequency in making water, or rather a continued inclination to void it, and a heaviness approaching to pain about the hips and loins. The uncommon symptoms in this case was great flatulency in the stomach and bowels ; this last symptom was most probably a sympathy with the uterus. There may possibly be sympathies therefore with the ovaria. The inflammation frequently goes deeper than the surface of the parts; often running along the ducts of the glands, and affecting the glands themselves, so as to produce hard swellings under the surface of the inside of the labia, which sometimes suppurate, forming small abscesses, opening near the orifice of the vagina. These are similar to the inflammations and suppurations of the glands in the urethra in men. The different surfaces or parts which the disease attacks, make no distinction in the disease itself. It is immaterial whether it is a large or small surface: in one case the parts are more susceptible of this irritation than in another; but the method of cure may be more complicated. It sometimes happens that the venereal matter from the vagina runs down the perinaeum to the anus, producing a gonorrhoea or chancres there. How far the gonorrhoea in women is capable of wearing itself out, as in men, I cannot absolutely determine; but am° much OF THE GONORRHOEA IN WOMEN. 65 inclined to believe that it may, for I have known many women who have got rid of a violent gonorrhoea without having used any means to cure it; and indeed the great variety of methods of cure employed in such cases, all of which cannot possibly do good, though the patients get well, seems to confirm this opinion. One circumstance, which appears as curious as any, is the seeming continuance of the disease in the vagina for years; at least we have reason to believe this, as far as the testimony of patients can be relied on; and this long continuance of it, without wearing itself out as it does sometimes in men, is probably owing to its being less violent in the vagina.*

* A case is here added : "The following account of a lady having all the symptoms of gonorrhoea immediately after connexion, shows how early in some cases the disease is produced; it was sent to me from Bath for my opinion upon it, drawn up by her medical attendant. "A lady of a delicate habit of body, great sensibility of mind, and extreme irritability of the whole nervous system, in general had enjoyed good health until her present illness, which began in the following manner. The morning after her marriage she complained of great soreness and swelling of the pudenda, attended with a good deal of pain, and difficulty in making water ; this was considered as the natural consequence of her connexion, and she continued her journey in a post-chaise, though in much pain, the whole day. The following morning her complaints were much increased, and a considerable discharge came on from the parts. In this situation she came to Bath a few days after, when I was desired to see her. I found her in an agony of distress, her husband having informed her, that, from circumstances attending himself, he was apprehensive her complaints might prove venereal. Upon questioning him, 1 found that for some months he had had a running from the urethra attended with heat of urine ; that he had been under the care of a surgeon in the country, who had assured him his disease was not venereal; that, confiding in this assurance, he had married, not doubting that he was perfectly well, except a trifling gleet which remained still: he further stated, that in having connexion with his wife, from the natural tightness of the parts he had not been able to penetrate ; that in the attempt she complained of much pain, and some blood was discharged : upon examining his shirt, some discharge was observed upon it, and he still was troubled with heat of urine. I was at first inclined to hope that (as women are not so easily infected with the venereal poison as men) all these complaints might be the consequences of a first connexion, followed by a long and rapid journey in a post-chase ; I therefore ordered an opening mixture, and desired the parts might be fomented with a decoction of poppy-heads in milk and water, and a soft poultice of bread and milk applied. Finding no advantage from the use of these means, I examined the state of the parts affected, and found there was a considerable discharge of matter, principally from the urethra, the orifice of which was much swelled and inflamed, as well as the ducts of the glands on each side the urethra: there did not appear to be any discharge from the vagina ; the hymen still appeared unbroken, and very firm and fleshy; the lacunae from Cowper's glands on each side were very much inflamed; and there was a hard tumour on one side of the hymen, which afterwards suppurated. There was no appearance of disease anywhere about the labia or nymphae. It was treated as venereal, and she went through a course of mercury, which was persisted in for some time : the abscess above mentioned burst; her mouth grew a little tender; her complaints were so much mended, that there was no doubt of a speedy and happy termination of her disorder, when she was seized with a most violent diarrhoea, which was with the utmost difficulty restrained. Mercurials of every kind were then left off; the former symptoms grew more troublesome; 7 66 HUNTER ON THE VENEREAL DISEASE. § 1. Of the Proofs of a Woman having this Disease.

It may be asked what proof there is of a woman having a gonorrhoea when she is not sensible of having any one symptom of the disease, and none appears to the surgeon on examination. In such a case, the only thing we can depend upon is the testimony of those whom we look upon as men of veracity. Such men have asserted that they have been affected by a woman in the situation above described, having had no connexion for some months with any other woman. From this evidence it is reasonable to suppose that the disease has been caught from such women; and it should seem to put it beyond a doubt when the same woman gives the disease in this way to more than one man. The case of the woman giving the disease to two men alternately at an interval of twelve months each time,* which gives a space of at least two years for the continuance of the disease, proves that its communication is almost the only criterion of its presence. The case too of the young woman at the Magdalen Hospitalf confirms the same opinion. Yet

the heat of urine increased, and extended to the bladder, as appeared by the continuance of the pain for an hour or two after she had made water. She was now desired to rub about a drachm of mercurial ointment upon the thighs, labia, and inside of the pudenda. About this time another abscess formed, in nearly the same situation with the former, which was opened with a lancet; this gave her much relief; the heat of urine went off in a great measure, but the discharge from the urethra still continued as much as before: she continued the mercurial frictions with great freedom during the healing of the abscess, insomuch that her mouth was greatly affected; she then left off the ointment for a little time, and soon after, the orifice of the urethra swelled and inflamed very much, the discharge greatly increased in quantity, and there was likewise a discharge of matter from the vagina; an injection of crude mercury rubbed down with mucilage of gum arabic till it was extinguished, and mixed with water, was ordered to be used twice or thrice a day; she had all along taken the almond emulsion with gum arabic for her constant drink, and this was continued in large quantities ; she also again resumed the nse^of the ointment as before, by which her mouth was at times made exceedingly sore. "The disease had now continued nearly five months ; the catamenia regularly appeared ever since her first complaint; at the last return of them she was free from pain, and the discharge as little as it had been at any time during her illness, and she continued free from uneasiness during that period, but soon after its cessation the heat of urine again returned in a most violent degree, and continued for an hour or two, with unabating violence; the orifice of the urethra again swelled as much as before. The discharge from the vagina at present is much the same, to which is superadded a shooting pain in almost every direction of that passage and the parts adjacent, which frequently recurs during the day. I can feel no swelling of any other part within the reach of my finger; nor does the pressure give pain in any direction. Being now fully persuaded that the venereal virus must be fully subdued, all mercurials are left off, and she uses only an injection of opium and thin starch, keeping the bowels open with a little castor oil now and then. Every fresh return of the ardor urinse has been accompanied with a train of most distressing nervous symptoms, hysterics, and extreme dejection of spirits, and the pain is generally most violent in the night, though she drinks an astonishing quantity of diluting liquors with gum arabic, pulvis tragacanth., comp., &c, and has frequently taken opiates, from which she has certainly received relief; but as they always increase her nervous symptoms, she is greatly overcome by their use."—Home. * See p. 43. -j- See p. 44. OF THE EFFECTS OF GONORRHOEA. 67

all this does not amount to an absolute proof; for a sound woman may have had a connexion with a man who had a gonorrhoea, or a man with chancres, and soon after, that is, perhaps within fortyeight hours, she may have admitted the embraces of a sound man. In such a case it is very possible that he may receive the infection from that matter which was lodged in the vagina by the unsound man, and yet the woman may not catch the disease, for the matter may be washed away before it irritates the vagina ; and this woman may be suspected of having a gonorrhoea, and apparently with great justice. A repetition of these circumstances may be the cause of many women appearing to have the disease for years, without really having it. Again, I have seen a bubo come on at a time when the patient was not sensible of any disorder till that appeared. This, one would think, is an absolute proof that there may be a gonorrhoea, and the patient not be conscious of it. But even this is not altogether without fallacy ; for there may have been an absorption of venereal matter deposited in the vagina by some infected man, which may not have produced any irritation in that part.* CHAPTER III.

OF THE EFFECTS OF THE GONORRHOEA ON THE CONSTITUTION IN BOTH SEXES.

The disease I have been describing, both in men and women, is local, and generally confined to the part affected; yet it sometimes happens that the whole constitution is more or less affected by it. Thus wre find, before there is any appearance of matter from the parts, that some patients complain of slight rigors: these are most considerable when the suppuration is late in taking place. A remarkable instance of this happened in a gentleman who had the infection twice.f The first time he assured me that it was six weeks between the time it was possible for him to have contracted the disease, and its appearance; and that for a considerable part of that time he had often been indisposed with slight rigors, attended with a little fever and restlessness, for which he could assign no cause, nor was he relieved by the usual remedies prescribed in such cases. A violent gonorrhoea came on, and these symptoms went off, which appeared to me to explain the case. The second time it was a month from the time of infection before the gonorrhoea appeared, and for some weeks of that time he was subject to a similar indisposition, which went off as before when the running came on.

* The last three sentences omitted.—Home. t The case is mentioned before, p. 43-4. 68 HUNTER ON THE VENEREAL DISEASE. Here it would appear that wc have something of a suppurative fever, which perhaps often happens in this disease ; but the inflammation being small, and the fever therefore inconsiderable, it is commonly little noticed by the patient. The above gentleman, not suspecting any such complaint in the first attack, had connexion with his wife as usual, and was afraid, when the disease appeared, that he might have given it to her ; but she never complained, which is a strong circumstance in confirmation of the principle laid down above, that it cannot be communicated but by matter. These constitutional sympathies from local specific diseases are the same, from whatever cause they proceed : they are the sympathetic effects of irritation or of violence. And it is probable that all remote sympathies are, at least in this respect, similar; for if they were similar to their cause, it is most probable that they would produce in the constitution the same kind of disease that gave rise to them. CHAPTER IV.

OF THE CURE OF THE GONORRHOEA.

From the idea which I have endeavoured to give of the venereal disease in general, namely, that, in whatever form it appears, it always arises from the same cause, it might be supposed that, since we have a specific for some of the forms of the disease, this specific should be a certain cure for every one ; and therefore that it must be no difficult task to cure the disease when in the form of inflammation and suppuration upon the secreting surfaces of any of the ducts or outlets of the body. But from experience we find the gonorrhoea the most variable in its symptoms while under a cure, and the most uncertain with respect to its cure, of any of the forms of this disease ; many cases terminating in a week, while others continue for months, under the same treatment. The only curative object is, to destroy the disposition and specific mode of action in the solids of the parts; and as that is changed, the poisonous quality of the matter produced will also be destroyed. This effects the cure of the disease, but not always of the consequences. I have already observed that this form of the disease is not capable of being continued beyond a certain time in any constitution; and that in cases where it is violent, or lasts long, it is owing to the parts being very susceptible of such irritation, and readily retaining it. As we have no specific medicine for the gonorrhoea, it is fortunate that time alone will effect a cure: it is therefore very reasonable to suppose that every such inflammation ceases of itself: yet although this appears to be nearly the truth, it is worthy of consi- OF THE CURE OF GONORRHOEA. 69 deration whether medicine can be of any service in this form of the disease. I am inclined to believe it is very seldom of any kind of use, perhaps not once in ten cases: but even this would be of some consequence, if we could distinguish the cases where it is of service from those where it is not. Upon the idea that every gonorrhoea cures itself, I gave certain patients pills of bread, which were taken with great regularity. The patients always got well; but some of them, I believe, not so soon as they would have done, had the artificial methods of cure been employed. The methods of cure hitherto recommended, and still followed by different people of the profession, are of two kinds. They consist either of internal remedies or local applications. But in whichsoever of these two ways this disease is to be treated, we are always to pay more attention to the nature of the constitution, or to any attending disease in the parts themselves, or parts connected with them, than to the disease itself. The nature of the constitution is principally to be learned from the local effects; for the local effects of this poison are so different in different people as to require great variety of treatment; but this has been too little attended to, every one endeavouring to attack the immediate symptoms, as if he had a specific for a gonorrhoea. The first thing to be considered is the nature of the inflammation, whether violent or mild, whether common or irritable. Yet even when this is ascertained, we have not in all cases the cure in our power; for I have already observed that some people are very susceptible of this irritation, who are, as it were, insensible to others; and, on the contrary, many are easily affected by common inflammation, who are insensible to this. These last are rather uncommon dispositions, and the cure being always easy they demand little attention. When the symptoms are violent, but of the common inflammatory kind, which is to be collected from the attending circumstances, particularly the extent of the inflammation not exceeding the specific distance, the local mode of cure may be either irritating or soothing. Irritating applications in the present case may be attended with less danger than in the irritable inflammation,* and may alter the specific action; but to produce this effect it must be greater than the irritation from the original injury. The parts will afterwards recover of themselves, as from any other common inflammation. After all, however, I believe the soothing plan is the best at the beginning. If the inflammation be great, and of the * It is very difficult to give clear ideas of distinctions in disease, when they are not marked by something permanent as to time, space, &c. I have used the term " irritable inflammation," because I think this kind of inflammation takes place more in weak irritable habits than in others: it appears to be guided by no law that I am acquainted with. It may be called an ill-formed inflammation, as not going through the usual process to a natural termination, but continuing with little variation; and if such inflammation were to take place in the cellular membrane, it would rather produce an oedematons swelling than such as arises from the extravasation of coagulable lymph, which takes place in what I would call the true inflammation. 7* 70 HUNTER ON THE VENEREAL DISEASE. irritable kind, no violence is to be used in the cure (for it will only increase the symptoms), unless we know that the great degree ol inflammation arises entirely from a susceptibility of this irritation, and that there is no general irritability in the constitution, which seldom can be ascertained. In cases where the symptoms run high, nothing should be done that may tend to stop the discharge, either by internal or external means; for nothing would be gained thereby as we may stop the discharge, and not put an end to the inflammation. The constitution is to be altered, if possible, by remedies adapted to each disposition, with a view to alter the actions of the parts arising from such dispositions, and reduce the disease to its simple form. If the constitution cannot be altered, nothing is to be done but to allow the action to wear itself out. When the inflammation has considerably abated, and the disease only remains in a mild form, its cure may be attempted either by internal remedies or local applications. If a local cure be attempted, violence is still to be avoided, because it may bring back the irritation. At this period gentle astringents may be applied with a prospect of success; or, if the disease has begun mildly, and there are no signs of an inflammatory disposition either of the common kind or the irritable, in order to get rid of the specific mode of action quickly, an irritating injection may be used, which will increase the symptoms for a time, but when it is left off they will often abate or wholly disappear. In such a state of parts, astringents may be used; for the only thing to be done is to procure a cessation of the discharge, which is now the principal symptom.* In those cases where the itching, pain, and other uncommon sensations are felt for some time before the discharge appears, I should be inclined to recommend the quieting or soothing plan instead of the irritating, with a view to bring on the discharge, as that effect is a step towards a resolution of the irritation; but howfar it would really be the proper plan I cannot absolutely say, not having had experience enough in such cases. One thing, however, I think I may assert from reasoning, that to use astringents would be bad practice, as they would rather tend to prevent the discharge from taking place, which might prolong the inflammation and protract the cure. In cases of stricture, or in cases of diseased testicles, I believe, astringents should not be used; for we find in either case, while the discharge lasts, both complaints are relieved; therefore in such cases we should proceed with more caution than when all the parts are otherwise sound. If we had a specific for venereal gonorrhoea, it would still be a question whether this specific could cure the irritation before the full action had taken place.

* Added : " It is very common when the discharge is stopped by an injection, even of a mild kind, to have an uneasy sensation in the perineum, and continued on to the bladder, producing frequency in making water, and on the return of the discharge these sensations immediately cease."__Home. OF THE CURE OF GONORRHOEA. 71 ^ 1. Of the different Modes of Practice.—Evacuants,—Astringents.

The internal remedies commonly recommended in a gonorrhoea may be divided into evacuants and astringents. The evacuants are principally of the purgative or diuretic kind, and these not confined to any particular medicines ; for every practitioner supposes that he is in possession of the best. Some use mercurial evacuants, while others carefully avoid mercury in every form. The neutral salts have been given, from the idea of their being cooling. Some of the profession have kept principally to diuretics, perhaps with two views, as evacuants acting upon the urinary passages mechanically, to wash off the venereal matter, or as specifics for the latter purpose : nitre has been given with this view; besides, it has been supposed to lessen inflammation; but its virtues in this way I very much doubt. Under these different modes of treatment the patients always get well, and the cures are ascribed by each practitioner to his own method of treatment. To keep the body open in most cases, even when the patient is in other respects in health, must no doubt be proper ; but what idea can we form of an irritation, produced all along the intestinal canal, curing a specific inflammation in the urethra 1 Yet there are cases where a brisk purge has been of service, and even in some has performed a cure. But 1 suspect that in such cases the disease has been continued by habit only, and that this practice would not have succeeded in the beginning. A gentleman had a gonorrhoea, all the symptoms of which continued for two months, and by taking at once ten grains of calomel, which purged him most violently, he was almost immediately cured. The calomel could not have acted specifically, but by a kind of derivation : that is, an irritation produced in one part cured one that subsisted in another. But, even if it should be granted that in some constitutions purges have the power of making the solids less susceptible of this irritation, it cannot be supposed they will have this effect in every case ; in some constitutions they might debilitate, increase irritability, and of course increase the symptoms. These contrary effects must take place in different constitutions in which a medicine has no specific action. On the supposition of the cure being promoted by an evacuation from the blood, what service can purging out some of the blood in form of a secretion from one part do to an inflammation of another part ? On such a supposition, would not a sweat, or an increase of saliva by chewing tabacco, or stimulating the nose by snuff', all tend equally to cure a gonorrhoea ? But humours having been considered as the universal cause of every disease, especially those in which pus is formed or a discharge produced, and purging having been supposed to be the cure for humours, purgatives were of course made use of in this disease: and as the patients have always been cured, the practice became generally established. Those who recommended mercury in this form of the disease, did 72 HUNTER ON THE VENEREAL DISEASE. it most probably from the opinion that this medicine was a specific for the venereal disease in all its forms. On this supposition, we can see some reason for their practice, as it would be absorbed from the intestines, circulate through the inflamed vessels of the urethra, and thereby destroy the venereal irritation. Here we can only suppose it to act by its specific virtue ; but I doubt very much of mercury having any specific virtue in this species of the disease, for I find that it is as soon cured without mercury as with it; and where this medicine is only used as a purge, or purged off the next day, and therefore allowed to act merely upon the bowels, I cannot conceive that it could have any more effect upon the venereal inflammation in the urethra than an irritation in the bowels arising from any other purgative. So little effect indeed has this medicine upon a gonorrhoea, that I have known a gonorrhoea take place while under a course of mercury sufficient for the cure of a chancre. Whether the gonorrhoea arose from the same infection that produced the chancre I cannot say ; nor can it be easily determined in such cases. Men have also been known to contract a gonorrhoea when loaded with mercury for the cure of a lues venerea ; the gonorrhoea, nevertheless, has been as difficult of cure as in ordinary cases. A gentleman committed himself to my care, on the 27th of June, for the cure of two chancres and a bubo. I dispersed the bubo; but as he disliked the unction, I was obliged to substitute mercurius calcinatus daily instead of it, giving two grains in the evening and one in the morning. About the middle of July his mouth became sore, and the mercury was left off; we began its use again in a week, and he appeared to be quite well of his venereal complaints. I, however, continued the use of mercury, keeping his mouth sore; and on the 16th of August, while in this state, he had a connexion with a woman, both on that and the following evening, and in five days after a gonorrhoea appeared, and proved to be very violent.* The same general observations may be made with regard to the effects of diuretics, considered as evacuants. It is possible that specific medicines taken into the constitution (if we had such), and passing off by urine, might act upon the urethra in their passage through it. The balsams and turpentines pass off in this way, and become specifics for many irritations in the urinary passages; but how far medicines which have the power of affecting particular parts when sound, or when under diseases peculiar to those parts, have also the powers of affecting a specific irritation in these parts, I know not; but do not believe they have any considerable powers in this way. It is possible, however, that they may remove any attending irritation, although not the specific one. Diuretics have, nevertheless, their advantages, for if they produce a greater quantity of water they do good; but I believe this had better be effected by simple water, or water joined with * Added : " Another gentleman, while under a course of mercury for the cure of chancres, had connexion with a woman before he left off the use of mercury, and in two days a gonorrhoea made its appearance."—Home. OF THE CURE OF GONORRHOEA. 73 such things as will encourage the patient to drink a good deal, as tea, syrup of capillaire, orgeate, and the like. Astringents, although often given, yet have always been condemned by those who have called themselves the judicious and regular practitioners; because, according to them, there is something to be carried off, and if that is not carried off a lues venerea is to be the consequence. This reasoning is not just; and therefore the question to be considered is, do they or do they not assist us in the cure of the gonorrhoea 1 I believe they do not, in any case, lessen the venereal inflammation; but certainly they often lessen the discharge. As that effect, however, does not constitute a cure, it is not necessary to produce it. I can conceive that a combination of astringents, especially the specific astringents of those parts, as the balsams, with any other medicine which may be thought to be of service, may help to lessen the discharge in proportion as the inflammation abates; and this I have often seen, as will be explained more at length hereafter.

§ 2. Of Local Applications—different kinds of Injections : irritating, sedative, emollient, astringent.

Local applications may be either internal to the urethra, external to the penis, or both ; all of which will in many cases be necessary. The internal, applied to the urethra, should seem the most likely to cure this species of disease, by coming immediately in contact with th*aJiseased parts; for if they have any power of action, whatever th^phe, it must be in opposition to the venereal irritation. Therefore we might suppose that most irritations that are not venereal would tend to a cure; but certainly this is not universally the case. If, on the contrary, the applications are such as quiet irritation, they must also be of service. Local applications to the urethra may be either in a solid or fluid form, each of which has its advantages and disadvantages. A fluid is only a temporary application, and that of very short duration, and is similar to the washing of a sore, which is, I believe, in most cases unnecessary; for I imagine that matter from any sore whatever is always such as cannot stimulate that sore into any action. It can be of no consequence, therefore, whether the matter is allowed to lie upon it or not; but it being removed, the medicines are allowed to come in contact, with the inflamed surface. I apprehend it is only in this way that the removal of it can be of service. The solid applications may remain a long time, and are similar to the dressings in the case of a wound. When the parts are not so much inflamed as to prevent the use of them, they would appear to have an advantage over the fluid applications by continuance ; but they in general irritate immediately, in consequence of their solidity alone. °These applications must be in the form of a bougie; but I should be inclined to suppose that the less use that is made of 74 HUNTER ON THE VENEREAL DISEASE. bougies, when these parts are in an inflamed state, the better, although I cannot say that I ever saw any bad effects from them in any case, when applied with caution. Fluid applications to the inside of the urethra are commonly called injections, and, like the internal remedies, are without number; every practitioner thinking, or washing to make the world think, that his own is the best. But, as every venereal inflammation is frequently removed under the use of injections of various kinds (which was observed with respect to internal medicines), have we not here a strong corroborating circumstance in favour of an opinion, that every such complaint will in time cure itself? I think, however, it appears from practice, that an injection will often have almost an immediate effect upon the symptoms, and that, therefore, they must have some powers; and yet the kind of injection which would have the greatest specific powers I believe is not yet known: if an injection has no specific powers, it must be very uncertain in its effects, and can only be of service as far as it may be adapted to a peculiarity of constitution or parts. As injections are only temporary applications, it becomes necessary to use them often, especially in cases where they are found to be of service ; they should therefore be applied as often as convenient, perhaps every hour, or even oftener ; but this must be regulated in some measure by the kind of injection, for if it be irritating it will not be proper to use it so often, as it may be productive of bad consequences. Many injections immediately, or at least soon after the application, remove the symptoms, and prevent the formation of matter, which has given rise to the notion of their shutting up the disease, and driving it into the constitution; but this supposed mode of producing a constitutional complaint is the reverse of what really happens, for I have already endeavoured to prove that matter is the only substance in which the poison is contained, and that the formation of the poison is inseparable from the formation of matter; therefore if we can prevent the one, the other cannot take place, and of course there can be no room for absorption; so that there can neither be any power of infecting the constitution in the same person, nor of communicating the infection to others.* When the discharge is an effect of present inflammation it may be stopped by injections, though the inflammation still continue in some degree, and may afterwards be removed without the discharge ever re-appearing. But I believe that by this practice little is gained, for the effect of the inflammation is not the disease which we wish to remove. However, we find that the same method which stops the discharge also removes the inflammation, although not always, and only I believe when the inflammation is slight. I shall divide injections, according to their particular effects upon the urethra, into four kinds,—the irritating, sedative, emollient, and astringent. The specific, I believe, is not yet discovered, although a

♦ Vide p. 21, what was said of the method of contracting the lues venerea. OF THE CURE OF GONORRHOEA. 75 mercurial injection, in some form or other, is by most people supposed to be possessed of such a power, and of course this mineral makes part of many of the injections now in use. Irritating injections, of whatever kind, I suspect in this disease act upon the same principle; that is, by producing an irritation of another kind, which ought to be greater than the venereal, by which means the venereal is destroyed and lost, and the disease is cured, although the pain and discharge may still be kept up by the injection. Those effects, however, will soon go off when the injection is laid aside, because they arise only from its irritating qualities. In this way bougies, as well as many injections, may be supposed to form a cure; and although they increase the symptoms for the time, they never can increase the disease itself, any more than the same injection which would produce the same symptoms, if applied to the urethra of a sound man, can communicate the disease. Most of the irritating injections have an astringent effect, and prove simply astringents when mild, their irritating quality depending chiefly upon their strength. As irritating injections do not agree with all inflammations arising from the venereal poison,* it may be asked, In what cases are the irritating injections to be used with advantage ? This I have not been able to determine absolutely; but I think irritating injections should never be used where there is already much inflammation, especially in constitutions which cannot bear a great deal of irritation, as a previous knowledge of the disease in the same person sometimes teaches us ; nor should they be used where the irritation has spread beyond the specific distance; nor where the testicles are tender; nor where, upon the discharge ceasing quickly, they have become sore; nor where the perinasum is very susceptible of inflammation, and especially if it formerly has suppurated ; nor where there is a tendency in the bladder to irritation, which is known from the patient having had for some time a frequency in making water. In such cases I have not succeeded with them; they not only do no good, but they often do harm, for I have seen them make the inflammation spread further in the urethra ;f and I think I have had reason to suspect that they have been the cause of abscesses in perinaeo. But in cases that are mild, and in constitutions that are not irritable, injections often succeed, and remove the disease almost immediately. The practice, however, ought to be attempted with caution, and not, perhaps, till milder methods have failed. Two grains of corrosive sublimate, dissolved in eight ounces of distilled water, are nearly as good an injection as any of the kind. But an injection of only half this strength may be used where it is not intended to attempt a cure so quickly. If, however, the injection, even in that

* For I have already remarked, that the inflammation varies according to the constitution. ■f It is, however, to be remarked, that this symptom is not always to be attributed to the injection, for it often happens when none has been used. 76 HUNTER ON THE VENEREAL DISEASE. proportion, gives considerable pain in its application, or if it occasions a great increase of pain in making water, it should be diluted. Sedative injections will always be of service in cases where the inflammation is considerable, not by lessening the disease itself, but by lessening the diseased action, which always allows the natural actions of the part more readily to take place. They are likewise very useful in relieving the painful feelings of the patient. Perhaps the best sedative we have is opium, as well when given by the mouth or anus, as when applied to the part affected in the form of an injection. But even opium will not agree, or act as a sedative, in all constitutions or parts. On the contrary, it has often opposite effects, producing great irritability. Lead may be reckoned a sedative, so far as it abates inflammation, while at the same time it may act as a gentle astringent. Fourteen grains of saccharum saturni, in eight ounces of distilled water, make a good sedative astringent injection. The drinking freely of diluting liquors may, perhaps, be considered as having a sedative effect, as it in part removes some of the causes of irritation, rendering the urine less stimulating, either to the bladder, when the irritation is there, or to the urethra in its passage through it; and it is possible that diluting may lessen the susceptibility of irritation. The vegetable mucilages of certain seeds and plants, and the emollient gums, are recommended; but I suspect that this practice is founded on a mechanical notion, and that none of them are of much service. I believe the advantage arises chiefly from the quantity of water that is drunk, and that if the water be joined with anything, spirits excepted, that can induce the patient to drink freely, the purpose is fully answered. I have, however, been informed by some patients, that they have thought that when the liquids they drank have been impregnated with mucilaginous substances, they have had less uneasiness in making water. Emollient injections are the properest applications where the inflammation is very great. They are most probably useful by first simply washing away the matter, and then leaving a soft application to the part, in which way I can conceive them to be of singular service, by lessening the irritating effects of the urine. Indeed practice proves this, for we often find that a solution of gum arabic, milk and water, or sweet oil, will lessen the pain and other symptoms, when the more active injections have done nothing, or have seemed to have done harm. It very often happens that the irritation is so great at the orifice of the urethra that the point of the syringe cannot be suffered to enter. When this is the case, nothing should be done in the way of injection till the inflammation abate. Emollients may likewise be used externally, in form of fomentation. The astringent injections can only act by lessening the discharge. They can have no specific effect upon the inflammation; but, as they must affect the actions of the living powers, it is possible they may alter the venereal disposition. They should only be used OF THE CURE OF GONORRHOEA. 77 towards the latter end of the disease, when it has become mild, and the parts begin to itch. But this should be according to circumstances, and, if the disease begins mildly, they may be used at the very beginning, for by gradually lessening the discharge, without increasing the inflammation, we complete the cure, and prevent a continuation of the discharge called a gleet. Injections of this kind very probably stimulate in such a way as to make the vessels of the part contract, and probably hinder the act of secretion. We can hardly suppose that they act chemically by coagulating the juices. They will have an irritating quality if used strong, which in some measure destroys their astringency, or rather makes the parts act contrary to what they would do from the application of a simple astringent. Thus, they often increase the discharge instead of lessening it; by which means the disease also may be cured, in the same way as by irritating injections, that is, by altering the disposition of the inflammation. When more mild they often stop the discharge, without, however, in all cases, hastening the cure ; for the inflammation may still continue even longer than it otherwise would have done if the tendency to secretion had not been stopped. I have already observed, that a surface that discharges has assumed the complete action of the disease, which is one step towards a cure or termination. However, it sometimes happens that an astringent injection will cure a slight irritation in a very few days. My experience has not taught me that one astringent is much better than another. The astringent gums, as dragon's blood, the balsams, and the turpentines, dissolved in water; the juices of many vegetables, as oak bark, Peruvian bark, tormentil root; and perhaps all the metallic salts, as green, blue, and white vitriols, the salts of mercury, and also alum, probably all act much in the same way, although we may assert that they do not always act equally well in every gonorrhoea, for on our changing the injection we sometimes succeed after several others have been tried in vain. The external applications are generally poultices and fomentations, but they can be of little service, except when the external parts, such as the prepuce, glans, and orifice of the urethra, are in some degree inflamed; the last, indeed, is almost always more or jpcc 3tt6Cl6Q When the glands of the urethra are so much swelled so as to be felt externally, the application of mercurial ointment to the part may be proper; but most probably this will be of more service after the inflammation has subsided. Indeed, mercurial ointment is often applied to all the external surfaces of those parts when in a state of inflammation, with an emollient poultice over it. I am not perfectly satisfied of the utility of this practice. 8 78 HUNTER ON THE VENEREAL DISEASE. CHAPTER V.

OF THE CURE OF GONORRHOEA IN WOMEN.

In women the cure of the gonorrhoea is nearly the same as in men ; but the disease itself is milder, and the secondary symptoms less numerous in women. This arises from there not being so many parts to be affected, and from those parts not being either of so great extent, or so liable to inflammation. Hence the cure becomes more simple. When the disease is in the vagina only it is easily cured. Injections are the best means that can be used, and, after the use of them, it may be proper to anoint the parts, as far up as possible, with mercurial ointment,* and also to wash the external parts often with the injection. If the inflammation has attacked the urethra, injections there cannot be so conveniently used, as it is almost impossible for the patient to throw an injection into that canal. The injections recommended in the cure of men are equally serviceable here; but they may be made doubly strong, as the parts of women are not nearly so irritable as the common seat of this disease in men. If what I have said of the disease in women be just, we must see that it will be a difficult thing to say, with any degree of certainty, when the patient is well, because, whenever the symptoms have ceased, the surgeon and the patient will naturally suppose the cure to be complete; but a new trial of those parts may prove the contrary, or in cases where the disease has never affected the urethra, but only the vagina, and still more where no symptoms have ever been observed, it will be more difficult to fix the date of the cure; but general experience must direct the practitioner. When the inflammation runs along the ducts of the glands, whether those of the mouth of the vagina, or urethra, or affects the glands themselves, the same method is to be followed : in particular, the mercurial ointment is to be freely applied to the parts. If the inflammation on the mouths of the ducts is so great as to shut them up, the duct and glands will suppurate, and form abscesses; in such cases it will be necessary to open them, or enlarge the opening already formed, and dress the abscess as a chancre or bubo. In the case of a simple running the constitutional treatment will be taken notice of hereafter; but if any suppuration follow, the * How far mercurial ointment assists in the cure I have not been able to determine ; the use of it arises more from a kind of practical analogy than real experience in such cases. ° OF THE TREATMENT OF THE CONSTITUTION. 79

constitution is to be treated as in chancres or buboes, for most probably absorption will take place, and its effects must be guarded against. CHAPTER VI.

OF THE TREATMENT OF THE CONSTITUTION IN THE CURE OF THE GONORRHOEA.

In the cure of the gonorrhoea the constitution is in some cases to be as much attended to as the parts affected, if not more; but in general this is not necessary. The knowledge of the constitution is to be obtained in a great measure from the local symptoms, and as far as the constitutional treatment can be made similar to the local, they should correspond. We find in many strong plethoric constitutions, where both the powers and actions are great, that the symptoms are violent. These constitutions have generally a strong tendency to fever of the inflammatory kind ; and probably the most distinguishing mark of such a constitution is that of the symptoms not extending beyond the specific distance. Many medicines which might be of service in another constitution will often prove hurtful here, in so much as to increase the very symptoms which they were meant to relieve. I have seen even opiate clysters, though they relieved at first, yet in the end produce or increase fever, and by that means increase all the symptoms. I have seen the balsam capivi, given in such cases, increase the inflammatory symptoms, probably by stopping the discharge in part, which appears to be salutary. The treatment of such a constitution, when affected with this disease, consists chiefly in evacuations, the best of which are bleeding and gentle purging. To live sparingly, and above all to use little exercise, is necessary; for although such a treatment does not lessen the venereal irritation, yet it lessens the violence of the inflammation, and allows the parts to relieve themselves. In this kind of constitution, therefore, the disease is in the end soonest cured, as there is not a tendency to a continued inflammation. In the weak and irritable constitution the symptoms are frequently very violent, arising from great action in the parts, and often extend beyond the specific distance, the inflammation running along the urethra, and even affecting the bladder. Instead of evacuations, which would rather aggravate the symptoms than relieve them, the constitution should be strengthened, and thus it will be less susceptible of irritation in general. I have seen patients whose constitutions were such that they were never sure of twenty-four hour's health, where the inflammation has been both considerable and extensive. I have seen evacuations tried, and the symptoms increased; but as soon as the bark 80 HUNTER ON THE VENEREAL DISEASE. was given freely they have become almost immediately mild, and without using any other medicine the patients have soon recovered. The medicine here acted upon the constitution, destroyed the irritability, gave the parts a true and healthy sense of the venereal irritation, and brought the inflammation to that state in which it ought to be in a healthy subject, whereby the constitution was enabled to cure itself. So capricious sometimes is this form of the disease in its cure, that the accession of an accidental fever has stopped the discharge, the pain in making water has ceased, and the gonorrhoea has finally terminated with the fever. In others I have seen all the symptoms of the gonorrhoea cease on the accession of a fever, and return when the fever has been subdued. In some I have seen a gonorrhoea begin mildly, but a severe fever coming on, and continuing for several days, has greatly increased the symptoms, and on the fever going off* the gonorrhoea has also gone off. Although a fever does not always cure a gonorrhoea, yet, as it possibly may, nothing should be done while the fever lasts ; and if it continues after the fever is gone, it is then to be treated according to the symptoms.* Unfortunately, there are cases where no known method lessens the symptoms; evacuations have produced no abatement; the strengthening plan has been as unsuccessful; sedatives and emollients have procured no relief; and time alone has performed the cure. In such cases the soothing plan, I believe, is the best, till we know more of the disease. Astringents should not be used, their action upon the inflamed parts being uncertain, for they often do not lessen the inflammation or the pain, although they may perhaps lessen the discharge. The turpentines, especially the balsam capivi and Canada balsam, lessen the disposition of the parts to form matter, which effect has always a salutary appearance; but as they have not at the same time the power of lessening the inflammation, they can be of little service. Besides the various effects arising from the difference of constitution in the gonorrhoea, we find that it is considerably affected by the patient's way of life during the inflammatory state, and also by other diseases attacking the constitution at the same time. But this is common to all other diseases, for whenever we have a local disease (in which light I have considered a gonorrhoea) it is always affected by whatever affects the constitution. Most things that hurry, or increase the circulation, aggravate the symptoms, such as violent exercise, drinking too much of strong liquors, eating strong indigestible food, some kinds of which act specifically on these parts, thereby increasing the symptoms more than by simply heating the body, such as peppers, spices, and spirits. From what has been said in general, it must appear that a gonorrhoea is to be cured in the same way as every other inflam-

* Added : " A gentleman, while using an injection for a gonorrhoea, was seized with a vomiting and purging, which brought on a fit of the piles; they bled profusely : as soon as he recovered from these attacks he found that all the symptoms of gonorrhoea had gone away."—Home. OF THE TREATMENT OF THE CONSTITUTION. 81

mation; and it must also appear that all the methods used are only to be considered as correctors of irritation in general, and of disordered circulation. In cases that have begun mildly, where the inflammation has been but slight, or in those cases where the violent symptoms above taken notice of have subsided, such medicines as have a tendency to lessen the discharge may be given, along with the local remedies before mentioned. The turpentines I believe are the most efficacious. Cantharides, the salts of some metals, such as of copper, zinc, and lead, and also some earths, as alum, are strongly recommended as astringents when given internally. Whatever methods are used for the cure, locally or constitutionally, it is always necessary to have in view the possibility of some of the matter being absorbed, and afterwards appearing in the form of a lues venerea, to prevent which I should be inclined to give small doses of mercury internally. At what time this mercurial course should begin is not easily ascertained ; but if the observation be just, that a disposition once formed is not to be cured by mercury, but that mercury has the power of preventing a disposition from forming, as was formerly explained, we should begin early, and continue it to the end of the disease, till the formation of venereal matter ceases, and even for some time after. The mercurial ointment may be used where mercury disagrees with the stomach and intestines. This practice appears to be more necessary if the discharge has continued a considerable time, and especially if the treatment has been simply by evacuants, for in the former case there is a greater time for absorption, and in the latter we may suppose a greater call for it, such medicines having no effect in carrying off the virus. To prevent a lues venerea being produced from absorption, a grain of mercurius calcinatus taken every night, or one at night and another in the morning, may be sufficient, but should be continued in proportion to the duration of the disease. The success of this practice in any particular case can never be ascertained, because it is impossible to say when matter has been absorbed, except in cases of buboes; and where it is not known to be absorbed, it is impossible to say that there would have been a lues venerea if mercury had not been given, as very few are infected from a gonorrhoea, although they have taken no mercury. It is, however, safest to give mercury, as we may reasonably suppose it will often prevent a lues venerea, as it does when given during the cure of a chancre or bubo, where we know, from experience, that without it the lues venerea would certainly take place.*

* [The principles which the author has laid down for the treatment of gonorrhoea, though generally correct, yet require some modification. In one or two instances he seems to have been misled by opinions, which are at the least very questionable. It is pretty well established, that a course of mercury is neither necessary nor useful in a gonorrhoea : it has no peculiar influence on the course of the disorder, 8* 82 HUNTER ON THE VENEREAL DISEASE. CHAPTER VII.

OF THE TREATMENT OF OCCASIONAL SYMPTOMS OF THE GONORRHOEA.

As the following symptoms are only occasional consequences of a venereal gonorrhoea, being the effects of an irritation on the urethra,

and it is an error to suppose that it is necessary for the sake of preventing secondary symptoms; and this is equally true, notwithstandiug the occurrence of suppuration in the glands of the urethra, or in the groin, or of breach of surface from any other cause. At the same time mercury is not particularly hurtful, except it be given in such doses, and for such a length of time, as would materially depress the general tone, render the urine alkaline, or induce universal irritability of the system. From the opinion, " that no matter of whatever kind can produce any effect on the part that forms it" (see p. 43), the author has been led to disregard altogether the discharge of gonorrhoea, and to conclude, that in no degree, and under no circumstances, is the inflammation increased by its stimulus, or relieved by arresting it. This doctrine, however, seerns scarcely consistent with experience. It is difficult to understand the effects of astringents in the early periods of the disorder, except on the supposition, that by arresting the discharge they relieve the urethra from the stimulus of the virus, and thus take away the very cause of the inflammation. Again, the distinction between venereal gonorrhoeas, and simple purulent discharges which are not derived from infection, is to be found less in the severity of the symptoms than in their obstinacy. The urethra is often attacked with inflammation as violent as that of gonorrhoea, in cases where there has been no possibility of infection. The discharge may be as copious, and exactly similar both in colour and appearance. But in these cases the inflammatory symptoms will in a few days spontaneously subside, and the discharge will diminish with it; whereas the inflammation and discharge of a gonorrhoea, shall, under similar circumstances, continue for weeks, or even months, without any visible abatement. Whence this difference, unless that in simple cases the cause is temporary, and hence the inflammation which it has excited soon exhausts itself; in gonorrhoeas a poison is generated, which acts as a perpetual stimulus, and constantly renews the excitement which originally gave rise to the disorder ? It does not appear that the plan on which a gonorrhoea should be treated differs from that which should be adopted in other inflammations of the urethra. But it must be remembered, that inflammation of mucous membranes generally, of Schneider's membrane for instance, or the inner membrane of the bladder, does not require, and is not benefited by much reduction ; and that, if the constitution be rendered irritable from weakness, these inflammations often become aggravated and obstinate. This rule, which is generally applicable to mucous membranes, is more especially important in all inflammations of the bladder and urethra, perhaps because depletion tends to change the state of the urinary secretion, and to render it alkaline and irritating. The duration and severity of a gonorrhoea depend much on the part of the urethra which is attacked by it. There is great variety in this respect. In most cases the inflammation is confined to the neighbourhood of the glans ; but in many it involves also the membranous portion, as may be shown, not only by the symptoms during life, but also by dissections after death. If the disease is limited to the last three inches of the urethra, it is seldom very violent or tedious; if it extends to the bulb and parts adjacent, the symptoms are most obstinate and distressing. Except in very rare instances, the disease commences TREATMENT OF OCCASIONAL SYMPTOMS. 83 and therefore not venereal, they are to be treated in the same manner as if they had arisen from any other cause.

§ 1. Of the Bleeding from the Urethra.

It has been already observed, that when the inflammation is violent, or spreads along the urethra, there is frequently a discharge of blood

at the glans. If it affects the membranous portion, it is by the progressive extension of the inflammation which gradually creeps up the urethra. This extension seldom occurs until the complaint has existed for a fortnight or longer, and if the cure can be effected within that time, may almost certainly be avoided. The true principles on which the treatment should be conducted will naturally follow from these considerations. If the patient be seen on the first access of the disorder, when the discharge has only just appeared, and is small in quantity, before the orifice of the urethra has become turgid, and the passage has become sensible to the stimulus of the urine, the disease may often be entirely arrested by astringent injections, or by internal medicines, which have the property of acting as astringents on the urethra, such as the balsam of copaiba, or cubebs. But such a result can only be obtained when the inflammatory symptoms have scarcely commenced, and are in the slightest possible degree. After the expiration of twenty-four hours it is often too late, and generally so at the end of forty-eight hours. When active inflammation is present, the stoppage of the discharge can seldom be effected completely, and scarcely ever permanently. It may be greatly diminished ; but this diminution rather aggravates than relieves the inflammation, as it lessens a secretion which has the effect of unloading the distended vessels, and the continuance of the inflammation will in a short time inevitably reproduce the discharge as profusely as before. It is to be observed, that it is necessary for the success of this plan that the discharge should be entirely stopped. If a single drop remains, it will go on to cause inflammation, and the disease will hold its ordinary course. Should the malady be in such a state as to render this mode of treatment hopeless, it will be necessary to allow it to run its natural course. A period will arrive when the urethra will become accustomed to the virus, and the inflammation will then spontaneously subside. In the mean time the surgeon must endeavour to moderate its violence, by the removal of all stimulants which can be avoided. The chief stimulants are the urine and the discharge. The urine must be rendered mild, by neutralising its acidity, and by copious dilution ; and the discharge must be moderated by astringent medicines, given in such doses as will only slightly check the increase of the secretion, without occasioning any immediate or sensible diminution in its quantity. Everything should be avoided which would determine to the parts affected. The diet should be light, and rather sparing, and no violent exercise should be taken; but there is no advantage in rigid abstinence or absolute rest, or in any restrictions which would interfere with the general health, or materially lower the general tone. However, should the inflammation extend to the parts surrounding the urethra itself, or, as Mr. Hunter expresses it, beyond the specific distance, this rule will not always apply. If there is tenderness and swelling of the perinaeum, or inflammation of the neck of the bladder, a horizontal posture and a careful regimen may be necessary. Yet even here it is better that blood should be abstracted locally and not generally, and that the diet should not be much reduced below the usual standard of health. When the inflammatory symptoms have nearly subsided; when the ardor urinae and chordee have disappeared, when the orifice of the urethra has lost its red and turgid aspect, and the discharge is less profuse and less purulent, astringents may again be given in full doses, and will generally complete the cure,] 84 HUNTER ON THE VENEREAL DISEASE. from the vessels of that part. In such bleeding, the balsam capivi, given internally, has been of service ; and it may be supposed that all the turpentines will be equally useful. I have not found any good effects from astringent injections, and in some cases have suspected that they have been the cause of this complaint. They always go off in the usual time of the cure of the gonorrhoea.*

§ 2. Of preventing Painful Erections.

Opium, given internally, appears to have great effects in preventing painful erections in many cases. Twenty drops of tinctura thebaica, taken at bedtime, have procured ease for a whole night. The cicuta likewise seems to have some powers in this way.

§ 3. Of the Treatment of the Chordee.

In the beginning of this complaint bleeding from the arm is often of service; but it is more immediately useful to take away blood from the part itself by leeches, for we often find by a vessel giving way in the urethra, and a considerable hemorrhage ensuing, that the patient is greatly relieved. Relief will often be obtained by exposing the penis to the steam of hot water. Poultices likewise have beneficial effects, and both fomentations and poultices will often be assisted in removing inflammatiou by the addition of camphor. Opium given internally, is of singular service, and if it be joined with camphor the effect will be still greater; but opium in such cases acts rather by lessening the pain than by removing the inflammation, though by preventing erections it may be said to obviate the immediate cause of the complaint. When the chordee continues after all other symptoms are gone, little, or nothing, in the way of evacuation, seems to be necessary, the inflammation being subdued, and a consequence of it oniy remaining, which will cease gradually by the absorption of the extravasated coagulable lymph. Therefore bleeding in this case can be of no use. Mercurial ointment applied to the parts will promote the absorption of the extravasated coagulable lymph, for experience has shown that mercury has considerable powers in exciting absorption. The friction itself also will be of use. In one case considerable benefit seemed to result from giving the cicuta, after the common methods of cure had been tried. Electricity may be of service. This symptom is indeed often longer in going off than either the running or pain ; but no bad consequences arise from it. Its declension is gradual and uniform, as happens in most consequences of inflammation.

* [Bleeding from the urethra in gonorrhoea is beneficial, and should very seldom be repressed. If, however, the quantity which is lost is very excessive, and it becomes necessary to check it, the application of cold, in the form of a bladder filled with ice, to the perinasum will be found by much the most effectual remedy.] TREATMENT OF OCCASIONAL SYMPTOMS. 85 In relieving the chordee, or the remains of it, which appear to arise from spasm, I have known the bark of great service. Evacuations, whether from the part or from the constitution, generally do harm.

§ 4. 0/ the Treatment of the Suppuration of the Glands of the Urethra.

Suppurations in the glands of the urethra are to be treated as chancres. Therefore mercury ought to be given, as will be explained hereafter. Should a suppuration take place in Cowper's glands, it demands more attention. The abscess must be opened freely and early, as the matter, if confined, may make its way either into the scrotum or urethra, whence would arise bad consequences. Here also mercury must be given, and perhaps as freely as in a bubo. In short, the treatment should be the same as in a venereal ulcer; and in this respect it will differ from the treatment of those abscesses which arise in consequence of stricture.*

§ 5. Of the Treatment of the Affection of the Bladder from Gonorrhoea.

When the disease extends as far as the bladder, it produces a most troublesome complaint, from which, however, bad consequences seldom arise. But I suspect that it sometimes has laid the groundwork of future irritation in that part, which has proved very troublesome and even dangerous. Opiate clysters, if nothing in the constitution forbid the use of them, procure considerable temporary relief. The warm bath is of service, although not always; and bleeding freely, if the patient is of a full habit, often does good. Leeches also, applied to the perinaeum, have good effects. But in many constitutions bleeding will rather do harm ; and we should be cautious in making use of this evacuation, for it has been already observed that many of these cases are rather from sympathy than inflammation. As this affection of the bladder often continues for a considerable time, producing other sympathies in the neighbouring parts, and is not in the least mitigated by the methods commonly used, I would recommend the following trials to be made use of in such cases. An opiate plaster to be applied to the pubes, or the small of the back, where the nerves of the bladder take their origin; a small blister on the perinasum, which is of service in irritations of the bladder arising from other causes.

* [Experience does not confirm this doctrine. Suppurations in the glands of the urethra are not very uncommon in gonorrhoea, yet they heal readily without the use of mercury ; nor are they ever followed by secondary symptoms.] 86 HUNTER ON THE VENEREAL DISEASE. § 6. Of the Treatment of the Swelled Testicle.

When the testicle sympathises either with the urethra or bladder, and is inflamed, rest is the best remedy. The horizontal position of the body is the easiest, as such a position is the best for a free circulation. If the patient cannot submit to a horizontal position, it is absolutely necessary to have the testicle well suspended. Indeed the patient will be happy in having recourse to that expedient as soon as he is acquainted with the ease which it affords. In this complaint, perhaps, no particular method of cure can be laid down. It is to be treated as inflammation in general, by bleeding and purging, if the constitution requires them, and by fomentation and poultices. Bleeding with leeches has often been of service. This we cannot well account for, as the vessels of the scrotum have but little connexion with those of the testicle. As I do not look upon the swelling of the testicle to be venereal, mercurials, in my opinion, can be of no service in these cases while the inflammation continues; but they are useful when that is gone and the induration only remains.* Vomits have been recommended in such cases, and are sometimes of service. I have known a vomit to remove the swelling almost instantaneously. The effects of the vomit most probably arise from the sympathy between the stomach and the testicle. Opiates are of service, as they are in most irritations of those parts. When such swellings suppurate, which they seldom do, they require only to be treated as common suppurations, and mercury need not be given. In the history of this disease I observed, and indeed it has been observed by most writers, that when a swelling comes upon the testicle in consequence of a gonorrhoea the running ceases, or when the running ceases the testicle swells; but which is the cause, or which is the effect, has not yet been ascertained. It has been also observed that when the running returns, the testicle then shows the first symptoms of recovery; so that the testicle having lost its sympathizing action, the action is restored to the urethra. And here also it has not yet been ascertained which is the cause or which is the effect; but, from a supposition that the cessation of the discharge in the urethra is the cause of the swelling, it has been attributed to the mode of treatment of that irritation, and by some to injections. It has been advised by many, and attempted by some, to procure a return of the running; but the methods used have hardly been founded upon any sound principle. Mr. Bromfield appears to have been the first who recommended a treatment suitable to this theory,

* [Though mercurials are not required for the sake of counteracting the venereal virus, yet experience shows that calomel is of the greatest service, even in the acute stage of inflammation of the testicle. It is probable that it acts here, as in many other cases of adhesive inflammation, by controlling the capillary circulation of the inflamed part. It should always be combined with purgatives, and generally with local bleeding.] TREATMENT OF OCCASIONAL SYMPTOMS. 87

which was to irritate the urethra to suppuration again, by introducing bougies. I have not seen that benefit that could have been wished, or that the first idea might induce us to expect, from this practice. Some have gone further, by recommending the introduction of venereal matter into the urethra; but this appears to be only conceit, and is founded upon a supposition that such swellings arise only from venereal irritations. But I have already observed that they are produced by other causes. It is generally a long time before the swelling of the testicle entirely subsides, although it does so more quickly at first than swellings of this part arising from other causes. Before it becomes less, it generally becomes softer, commonly on the anterior surface; and by degrees the whole becomes perhaps softer than natural, and then it diminishes. It is still much longer (sometimes even years) before the epididymis returns to its natural state; sometimes it is never reduced to its natural size and softness. However, this is of no great consequence, as no inconvenience results from a continuance of the hardness simply; though sometimes, perhaps, such testicles are rendered totally useless. I never had an opportunity of examining the testicle of one that was known to have this complaint; but have examined testicles where the epididymis has had the same external feel, and where the canal of the vas deferens has been obliterated. But this, I suspect too, seldom happens, for there are people who have both testicles swelled, and, notwithstanding, discharge their semen as before.* It is in this stage of the complaint that resolvents may be of service, such as mercurial friction joined with camphor. Likewise we may usefully apply fumigations with aromatic herbs, in order to stimulate the absorbents to take up the superfluous matter. Electricity has been in some cases of singular service.

§ 7. Of the decline and termination of the Symptoms of Gonorrhoea.

The decline of the disease is generally known by an abatement of some or all of the above-mentioned symptoms. The pain in the part becomes less, or terminates in an itching similar to what is felt in the beginning of many gonorrhoeas, and at last entirely goes off. The sense of weariness about the loins, hips, testicles, and scrotum is no longer felt; and the transparent cherry-like appear-

* [The hardness which is left after inflammation of the testicle does not appear in most instances to interfere with its functions. The obliteration of the vas deferens is not a frequent occurrence ; and the induration which often remains in the epididymis, is usually from deposition in the cellular membrane which connects its convolutions, or mere thickening of the membranes which invest it, and though it is not uncommon that some of the vasa efferentia should be totally obstructed, and converted into solid cords : yet unless the whole of these vessels should be thus changed, such an occurrence is of little consequence; as those which still remain pervious will be sufficient to cany the semen as before into the vas deferens.] 88 HUNTER ON THE VENEREAL DISEASE.

ance of the glans penis gradually disappears. These are the most certain signs of an abatement of the disease. The running becomes less; or, if it does not diminish, becomes first whiter, then of a paler colour, and gradually acquires a more slimy and ropy consistence, which has always been considered as the most certain sign of an approaching cure. When the running becomes more slimy, it is then changed from matter to the natural fluid which lubricates the passage, and also to that fluid which appears to be preparatory to coition. But it is often very inconstant in its appearances, arising frequently from different modes of living, exercise, or other causes. It often happens that all the symptoms shall totally disappear, and the patients shall think themselves cured, and yet the same symptoms shall come upon them anew, commonly indeed milder than at first, though in some cases as violent, or even more violent; and this takes place sometimes at a considerable distance of time. I have known the symptoms return a month after every appearance of the disease has been removed. However, in such cases, they seldom last long. How far this second attack is to be looked upon as truly venereal has not as yet been ascertained. Nothing can prove it absolutely to be venereal but the circumstance of having given it to a sound person. What may be the case with those in whom it has returned soon after the going off of the symptoms, I will not pretend to say; but I should very much suspect that, where the patient has continued well for a month, a return cannot be venereal. This is only conjecture; and if we were to reason upon it we might easily reason ourselves into a belief of its being venereal; for if the parts can fall back again into one mode of action, that of inflammation and suppuration, there can be no reason why they should not fall back again into the specific mode of action. However, as the common effect of irritation is suppuration, and as the specific suppuration requires a peculiar irritation, it is easier to conceive that the parts may fall into the common mode of action than into both. It is possible, however, that in such cases the venereal action may be only suspended, similar to what happens between the contamination and complete appearance of the disease. In women, returns of the symptoms are more frequent than in men, particularly of the discharge; which being similar to the fluor albus, and frequently taken for that disease, gives less suspicion, although they are perhaps equally virulent as those in men. The distinction between a gonorrhoea and a gleet is not yet ascertained; for the inflammation subsiding, the pain going off, and the matter altering are no proofs that the poison is destroyed. It is no more necessary that there should be a continuance of the inflammation to produce the specific poison than that there should be a continuance of the inflammation to produce the gleet, as will appear evident from two cases before related.* * Vide pages 44 and 45. OBSERVATIONS ON THE SYMPTOMS, ETC. 89 The first of these cases shows that the inflammation is not necessary to the existence of the venereal poison; and, on the contrary, the inflammation may exist after the matter discharged has ceased to be venereal. I have known cases where the inflammation and discharge have continued for twelve months, and with considerable violence : in the mean time a free intercourse with women has not communicated the disease. However, this is not an absolute proof that there is no virus in the discharge. CHAPTER VIII.

OBSERVATIONS ON THE SYMPTOMS WHICH OFTEN REMAIN AFTER THE DISEASE IS SUBDUED.

It often happens, after the virus is destroyed and the venereal inflammation removed, that some one, two, or more of the symptoms- shall continue, and perhaps prove more obstinate than the original disease itself. Some of these symptoms shall continue through life, and even new ones shall sometimes arise as soon as the first have subsided. All these symptoms are commonly imputed by the patients themselves, and what is still worse, by some of the profession, to the original disease having been ill treated. But certainly, so far as we are yet acquainted with the disease and method of cure, this is not true; for the methods of treatment, though numerous, may be said to be very similar; and we shall find these symptoms not to be consequences of any one mode of treatment, but that they happen indiscriminately after them all. Yet I can conceive that many constitutions and particular parts often require one mode of treatment in preference to another, and probably require modes that we are not as yet acquainted with; but if these peculiarities of constitution or of parts are not yet known, which must often be the case, the practitioner is not to be rashly accused of ignorance. In the Introduction, I observed that the venereal disease is capable of calling into action such susceptibilities as are remarkably strong, and peculiar to certain constitutions and countries; and that, as the scrofula is predominant in this country, some of the effects of gonorrhoea may partake of a scrofulous nature. The symptoms which continue after the virus is gone do not owe their continuance to the specific qualities of the virus, but to its effects upon the parts, such as inflammation and its consequences; for the same degree of inflammation, arising from any other cause, would leave most of the same effects. But 1 suspect that the continuance of the discharge called a gleet is an exception to this; for 90 HUNTER ON THE VENEREAL DISEASE. we find that it is often cured by the same mode of action which would produce the other symptoms, that is, inflammation; and we find in general that a discharge brought on by violence of no specific kind does not last longer than the violence, even although the cause has been continued for some time, as .is often the case during the use of bougies. The first of the continued symptoms may be reckoned the remains of the disagreeable sensations excited by the original disease. The second, the discharge called a gleet. The third, the chordee. The fourth, the irritable state of the bladder. The fifth, the increase and hardness of the epididymis.

§ 1. 0/ the remains of the disagreeable Sensations excited by the original Disease.

The disagreeable sensations which continue in the urethra and glans occur most frequently when the bladder has sympathised with the urethra during the disease ; for then there are often the remains of the old shooting pains in the glans, or on its surface, which take their rise from the bladder. These, howrever, commonly go off, seldom being the forerunners of any bad symptoms, and therefore are not to be considered as part of the disease, but merely a consequence ; yet they are often very troublesome and teazing to the patient, keeping his mind in doubt whether he is cured or not, which makes him frequently become the dupe of ignorant or designing men. As these remaining sensations vary considerably in their nature, perhaps no one method of treatment will always be proper. I have known a bougie, introduced a few times, take off entirely the disagreeable sensation in the urethra; and I have known it to do no good. Gentle irritating injections, used occasionally, will often alleviate in some degree those^ complaints. A grain of corrosive sublimate to eight ounces of water makes a good injection for this purpose ; but all such applications are in general no more than palliatives. I have known the use of hemlock relieve the symptoms very much, and in some cases entirely cure them; while in many others it has not had the least effect. A blister applied to the perinasurn will entirely cure some of the remaining symptoms, even when they extend towards the bladder, as will be explained hereafter: indeed it appears to have more effect than any other remedy. A blister to the small of the back will also give relief, but not so effectually as when applied to the perinasurn. The following cases are remarkable instances of this. A Portuguese gentleman, about twenty-five years of age, had contracted a venereal gonorrhoea, of which he was cured ; but two years after, OBSERVATIONS ON THE SYMPTOMS, ETC. 91

many of the symptoms still continued, and even with considerable violence. The symptoms were the following: a frequency in making water, and when the inclination came on he could not retain it a moment; a straining, and pain in the bladder after voiding it; a constant pain in the region of the bladder; a shooting pain in the urethra, which extended often to the anus; strange sensations in the perinasurn ; a sense of weariness in the testicles; and if he at any time pressed his thighs close together the pain or sensation in the perinasurn was excited. It was supposed at Lisbon that he had the stone, and he came over to London for a cure of that disease. He was examined, but no stone was found. He was ordered to wash the external parts every morning with cold water, which he did for a fortnight, but found no benefit. I was consulted, and informed of all the above-mentioned circumstances. As a staff had been passed, there could be no stricture ; however, I thought it was possible there might be a diseased prostate gland, and therefore examined him by the anus, but found that gland of its natural size and firmness. As there was no visible alteration of structure anywhere to be found, I looked upon the disease as only a wrong action of the parts, and therefore ordered a blister to be applied to the perinasurn, which being kept open only a few days all the symptoms were entirely removed. He retained his water as usual; all the disagreeable sensations went off: and the blistered part was allowed to heal. About a fortnight after, he got a fresh venereal gonorrhoea, which alarmed him very much, as he was afraid it might bring back all his former symptoms, which however did not return, and he was soon cured of the gonorrhoea. He staid in London some time after, without any relapse. Another case was that of a gentleman's servant in the country. He had, from a venereal cause, a disagreeable sensation whenever he made water, also a running, and some degree of chordee ; which symptoms he had laboured under for a considerable time. He had gone through a course of mercury, which lasted two months, on a supposition that the venereal virus had not been destroyed ; but without benefit. He had after that been bled, used powders of gum arabic and tragacanth, and taken calomel in small doses, with no better success. He then had recourse to injections and bougies of all kinds, but with no better success. On the ground of the symptoms not being venereal, but only wrong actions of the parts, a blister was applied upon the perinasurn, repeated and kept open six days, upon which the symptoms totally disappeared, and had not recurred a twelvemonth afterwards. This practice is not only of service where there has been a preceding gonorrhoea, but I have found it remove, almost immediately, suppressions of urine from other causes, when the turpentines and opium, both by the mouth and anus, had proved ineffectual, and when the catheter had been necessarily introduced twice a day to draw off the water. But of this more fully hereafter. 92 HUNTER ON THE VENEREAL DISEASE. Electricity has been found to be of service in some cases, and therefore may be tried either in the first instance, or when other means have failed.

Whatever method has been had recourse to in the cure of the venereal inflammation, whether injections have been used, or internal medicines, (mercurials, purgatives, or astringents,) it often happens that the formation of pus shall continue, and prove more tedious and difficult of cure than the original disease. For, as I have already observed, the venereal inflammation is of such a nature as to go off itself, or to wear itself out; or, in other words, it is such an action of the living powers as can subsist only for a certain time. But this is not the case with a gleet, which seems to take its rise from a habit of action which the parts have contracted, and as they have no disposition to lay aside this action, it of course is continued; for we find in those gonorrhoeas which last long, and are tedious in their cure, that this habit is more rooted than in those which go off soon. This disease, however, has not always the disposition to continue, for it often appears to stop of itself, even after every method has been ineffectually used. It is most probable that this arises from some accidental changes in the constitution, not at all depending upon the nature of the disease itself. I have suspected that there was something scrofulous in some gleets. We find frequently that a derangement of the natural actions of a part will be the cause of that part falling into some new disease to which there may be a strong tendency in the constitution. We find that a cold falling on the eyes produces a scrofulous weakness in those parts, with a considerable discharge. There are often scrofulous swellings in the tonsils, from the same cause. This opinion of the nature of some gleets is strengthened by the methods of cure; for we find that the sea-bath cures more gleets than the common cold bath, or any other mode of bathing. I have never yet tried the internal use of those medicines which are generally given in the scrofula; but I have found sea-water, diluted and used as an injection, cure some gleets, though it is not always effectual. A gleet is generally understood to arise from a weakness: this certainly gives us no idea of the disease, and indeed there is none which can be annexed to the expression. By mechanical weakness is understood the inability to perform some action or sustain some force. By animal weakness the same is understood. But when the expression is applied to the animal's performing an uncommon or an additional action, I do not perfectly understand it. Upon this idea of weakness depended in a great measure the usual method of cure ; but we shall find that the treatment founded OBSERVATIONS ON THE SYMPTOMS, ETC. 93

on this idea is so far from answering in all cases that it often does harm, and that a contrary practice is successful. A gleet differs from a gonorrhoea: first, in this, that though a consequence of it, it is perfectly innocent with respect to infection; secondly, when it is a true gleet it is generally different in some of the constituent parts of the discharge, which consists of globular bodies, floating or wrapt in a slimy mucus instead of a serum. But the urethra is so circumstanced as easily to fall back into the formation of pus; and this commonly happens upon the least increase of exercise, eating or drinking indigestible food, or anything which increases the circulation or heats the patient. The virus, however, I believe, does not return; but of this I am not certain, for there are cases that make it very doubtful, as was before observed. I am inclined to suspect that a gleet arises from the surface of the urethra only, and not from the glands: for I have observed in several instances that when the passage has just been cleared, either by the discharge of urine or by the use of an injection, a lascivious idea has caused the natural slime to flow very pure, which I do suppose would not have happened if the parts secreting the liquor had assisted in forming the gleet.* A gleet is supposed to be an attendant upon what we call a relaxed constitution ; but I can hardly say that I have observed this to be the case: at least I have seen instances where I should have expected such a termination of a gonorrhoea, if this had been a general cause, but did not find it; and I have seen it in strong constitutions, at least in appearance, in every other respect. Gleets do not in all cases arise from preceding gonorrhoeas, but sometimes from other diseases of the urethra. A stricture in the urethra is, I believe, almost always attended with a gleet. It sometimes arises from a disease in the prostate gland. When a gleet does not arise from any evident cause, nor can be supposed to be a return of a former gleet in consequence of a gonorrhoea, a stricture or diseased prostate gland is to be suspected ; and inquiry should be made into the circumstances of making water, whether the stream is smaller than common, whether there be any difficulty in voiding it, and whether the calls to make it are frequent. If there should be such symptoms, a bougie, of a size rather less than common, ought to be used, which, if there is a stricture, will stop when it reaches it; and if it passes on to the bladder with tolerable ease, the disease is probably in the prostate gland, which should be next examined. But more fully of both these complaints hereafter.f * Added : "A gentleman has a gleet, occasionally attended with pain in making water: it is brought on by sitting in a post-chaise, if he sits on the cushion, but not if he sits on a hard seat; it never comes on after riding on horseback, but he believes that riding upon a padded saddle would produce it."—Home. \ | [A gleet may arise from any source of irritation in any part of the urinary passages, or even in the neighbourhood. Haemorrhoids are a frequent cause, and, in children, worms in the intestines. In like manner it may be occasioned 9* 94 HUNTER ON THE VENEREAL DISEASE. § 3. Of the Cure of Gleets—constitutionally—locally.

As this discharge has no specific quality, but depends upon the constitution of the patient or nature of the parts themselves, there can be no certain or fixed method of cure ; and as it is very difficult to find out the true nature of diflerent constitutions or of parts, it becomes equally difficult to prescribe with certainty the medicines that will best suit this disease ; for so great is the variety in constitutions, that what in one case proves a cure will in another aggravate the complaint. There are two ways of attempting the cure of this complaint: constitutionally, or locally. Medicines, taken into the constitution with a view to the cure of gleet, may be supposed to act in three ways: as specifics,* strengtheners, and astringents. The specific power of internal medicines upon those parts is not very great; however, we find that some of them, such as the balsams, turpentines, and cantharides, are of use, especially in slight cases. I think I have been able to ascertain this fact, that when the balsams, turpentines, or cantharides, are of service, they are almost immediately so ; therefore if upon trial they are not found to lessen, or totally remove the gleet in five or six days, I have never continued them longer. And even where they have either lessened or totally removed the gleet in that time, it will often recur upon leaving them off, and therefore they should be continued for some time after the symptoms have disappeared. I have known cases where the gleet has disappeared immediately upon the use of the balsam capivi, and recurred upon the omission of it; and I have also seen where that medicine has kept it off for more than a month, and yet it has recurred immediately upon laying it aside,

by a calculus, or by other disease in the bladder or kidneys, and still more commonly, as the author has stated, by stricture in the urethra. But perhaps the most common cause, if we except stricture, is some derangement in the secretion of the urine, by which that fluid is rendered too acid or alkaline, and is converted into a perpetual source of irritation, occasioning various derangements of the urinary organs, and none, at least in those who have suffered from gonorrhoea, more frequently than gleet. The cure of a gleet depends chiefly on the discovery, and the removal of the causes which excite it. While these continue, the effect of any remedies which are calculated to act directly on the discharge is generally inadequate, and at the best temporary. When the source of irritation, whatever it may be, is taken away, there is seldom much difficulty in repressing the excessive secretion from the urethra. The same remark applies to leucorrhcea in women. This is very generally kept up by some uterine derangement, as amenorrhea, or irritability of the os uteri. While this derangement subsists, no remedies are effectual: but if it is first corrected by appropriate treatment, the discharge may usually be arrested, without great difficulty, by a little perseverance in the use of the commonest astringents.] * It may be necessary to remark here, that by specific I do not mean a specific for the disease, but only such medicines as act specifically on the parts concerned, as the turpentines, cantharides, &.i. OBSERVATIONS ON THE SYMPTOMS, ETC. 95 and stopped again as quickly when the patient has returned to it. In such cases the other methods of cure should be tried. The balsams may either be given alone, or mixed with other substances, so as to make them less disagreeable.* The general strengtheners of the habit need only be given when the parts act merely as parts of that habit. The whole being disposed to act properly, these parts are also disposed to act in the same way. By general strengtheners are here meant, the cold bath, the sea bath, the bark, and steel. Astringents, taken into the constitution, have no great powers ; and if they had, they might be very improper, as anything that could act with powers in the constitution equal to what would be necessary here, might very much affect many natural operations in the animal economy. The astringent gums and salt of steel are commonly given. The second mode of cure is by local applications. These may be divided into four, which are, specifics, astringents, irritating medicines, and such as act by derivation. The specifics, applied locally, we may reasonably suppose, will have greater effects than when given internally, because they may be applied stronger than can safely be thrown into the circulation. Of this, I think, I have had experience. The astringents commonly used are the decoction of the bark, white vitriol, alum, and preparations of lead. The aqua vitriolica coerulea of the London Dispensatory, diluted with eight times its quantity of water, makes a very good astringent injection. The same observations that I made on the specifics are applicable to the astringents; I believe that they act nearly in the same manner, and have the same effect. What their mode of action is it is difficult to say. When either of these methods has been used, and has had the desired effect, it should be continued for a considerable time after the symptoms have disappeared; and the time must be in proportion to the duration of the complaint, or the frequency of its returns. If it has been of long standing, we may be sure that the disposition to such a complaint is strong; and if it has returned frequently, upon the least increase of circulation, we may expect the same thing to happen again. Therefore, to correct the bad habit, it is necessary to continue the medicines a considerable time. Irritating applications are either injections or bougies, simple, or medicated with irritating medicines. Violent exercise may be considered as having the same effect. Such applications should never be used till the other methods have been fully tried and found unsuccessful. They differ from the foregoing by producing at first a greater discharge than that which they are intended to cure ; and the increased discharge may or may not continue as long as the application is used. It becomes, therefore, necessary to inquire how

* Added : " I believe that the balsam of capivi cures a gleet more permanently than injections, its action being specifically upon the parts."__Home. 96 HUNTER ON THE VENEREAL DISEASE. long they are to be used to produce a cure of the gleet. That time will generally be in proportion to the violence used, and the nature of the parts which form the matter, and according to the disposition being strong or weak, joined to its duration, and the greater or less irritability of the parts. If the parts are either weak or irritable, or both, an irritating injection should not be used; if strong, and not irritable, it may be used with safety. In this last case, if it is an injection that stimulates very considerably, perhaps it may be sufficient to use it twice or thrice a day. I knew a gentleman who threw into the urethra, for a gleet of two years' standing, Goulard's extract of lead, undiluted, which produced a most violent inflammation ; but when the inflammation went off, the gleet was cured. Two grains of corrosive sublimate to eight ounces of water are a very good irritating injection. If it is a gleet of long standing, it may require a week or more to remove it, even with an irritating injection; and if the injection is less irritating, so as to give but little pain, and to increase the discharge in a small degree, it may require a fortnight. But one precaution is very necessary respecting the use of irritating injections; it should be first known, if possible, that they will do no harm. To know this may be difficult in many cases; but the nature of the parts is to be ascertained as nearly as possible ; that is, whether they had ever been hurt before by such treatment; whether they are so susceptible of irritation as that the irritation may be expected to run along the urethra and produce symptoms in the bladder, for in such cases irritating applications do not answer, but, on the contrary, often produce worse disorders than those they were meant to cure. Bougies may be classed with the irritating applications, and in many cases they act very violently as such. They appear to be more efficacious than injections, but they require longer time to produce their full effect. A simple, or unmedicated bougie, is, in general, sufficient for the cure of a gleet, and requires a month or six weeks' application before the cure can be depended upon. If bougies are made to stimulate otherwise than as extraneous bodies, then a shorter time will generally be sufficient. Probably the best mode of medicating them would be by mixing a little turpentine, or a little camphor with the composition, so as to act specifically on the parts; but great care should be taken not to irritate too much. The size of the bougie should be smaller than the common, and need only be five or six inches long, as it seldom happens that a greater extent of the urethra has the disposition to gleet; but no harm will arise from passing a bougie of the common length through the whole extent of the urethra. In the cure of a gleet attempted by means of the bougie, we have no certain rules to direct us when it should be left off, as the discharge will often continue as long as the bougie is used. If, upon leaving off the bougie, after the use of it for several weeks OBSERVATIONS ON THE SYMPTOMS, ETC. 97

the running ceases, then we may hope there is a cure performed; but if it should not be in the least diminished, it is more than probable that bougies will not effect a cure, and therefore it is hardly necessary to have recourse to them again. Yet, if the gleet is in part diminished, it will be right to begin again, and probably it may be proper to increase the irritating quality of the bougie, in order to suit it to the diminished irritability of the parts. The fourth mode of cure is by sympathy, or by producing an irritation in another part of the body, which shall destroy the mode of action in the urethra. I knew a case of obstinate gleet attended with very disagreeable sensations in the urethra, especially at the time of making water, removed entirely by two chancres appearing upon the glans. The patient had taken all the medicines commonly recommended, and had applied the bougie without effect. A gentleman informed me that he had cured two persons of gleets by applying a blister to the under side of the urethra ; and I have known several old gleets, after having baffled all common attempts, cured by electricity. All these diflerent methods of cure alter the disposition of the part. In whatever way the cure is attempted, rest or quietness in most cases is of great consequence; for, as I have observed, exercise is often a cause, not only of its continuance, but of its increase and return. But this idea is not to be too rigidly adhered to, especially in cases which have been treated unsuccessfully, as I have known some that have got immediately well by riding on horseback after long disuse of that exercise. Regularity and moderation in diet should be particularly attended to; for irregularities of this kind either hinder the cure or bring on a return of the disease. Intercourse with women often causes a return, or increase of gleet, and in such cases it gives suspicion of a fresh infection; but the difference between this and a fresh infection is, that here the return will follow the connexion so close as to be almost immediate, and that circumstance, joined with the other symptoms, will in general ascertain the nature of the discharge. The cure of the gleet in women is nearly the same as in men, except in the use of what I have called specifics to the parts, for as the gleet in women is principally from the vagina, I believe that this part is not more affected by the turpentines than other parts are ; but as the vagina is less irritable than the urethra in men, the astringents which are applied to it may be considerably stronger. Neither can we use the bougie in cases of gleet in the vagina; and when the gleet is only from the urethra, I imagine it is hardly ever attended to in women.

§ 4. Of the Remaining Chordee.

This symptom, I have already observed, often remains after 98 HUNTER ON THE VENEREAL DISEASE. every mark of the true virus is removed, and may or may not be attendant on any of the other continuing symptoms. Mercurial ointment applied to the part may be of service, and if joined with camphor, its powers will be increased. I have known electricity cure a chordee of long standing. If it is the spasmodic chordee that remains, bark should be given.

§ 5. Of the continuance of the Irritation of the Bladder.

The irritation of the bladder sometimes continues after every other symptom has ceased, and it may be an attendant upon -all, or any of the other continuing symptoms ; it seldom lasts with the same violence, although it is often very troublesome. When this irritation is kept up with the same violence, the bladder itself may be suspected of being diseased ; or it may arise from its connexion with other parts, such as the urethra, or prostate gland; for a stricture in the urethra coming on will prove the cause of its continuance, and a disease in the prostate gland will do the same. Neither of these diseases will probably follow the gonorrhoea so closely as to keep up this irritation, though perhaps they may have been taking place prior to the gonorrhoea, and so contribute to its increase and continuance, which may probably be ascertained by a history of the patient preceding the present complaint; however, before the bladder itself is attempted to be cured, a bougie should be passed, and if no stricture is found, then the prostate gland should be examined, as shall be described. When the disease is in the bladder only, I think the pain is principally at the close of making water, and for a little while after. The cure of this symptom consists in opiate clysters, cicuta, bark, sea-bathing, and I should be inclined to recommend the application of a blister to the perinasurn in men. How far opiate clysters can affect the bladder in women as they do in men, I am not certain.

§ 6. Of the remaining Hardness of the Epididymis.

This symptom I have observed remains long after every other symptom is removed, and may continue even for life; but seldom or ever any bad consequences happen from it if the vas deferens is not rendered impervious, and not even then if it is only in one testicle, the other being equal to all the purposes of generation. As this is the case, we must at once see that no certain method of resolution is yet known. The application of the steam of hot water with camphor may be tried, especially in such cases as are not disposed to be permanent; and the scrotum may be rubbed with mercurial ointment, joined with camphor. But in most cases this practice will prove too tedious, or rather too inefficacious to be long persisted in. SUPPOSED CONSEQUENCES OF GONORRHOEA. 99 PART III. CHAPTER I.

OF DISEASES SUPPOSED TO ARISE IN CONSEQUENCE OF VENEREAL IN- FLAMMATION IN THE URETHRA OF MEN.

The gonorrhoea produces, or at least is supposed to produce, besides those disorders already mentioned, many others which are totally different from the original disease. How far they do all or any of them arise in consequence of this disease, is not clear: but as they are diseases of the urethra, and are both numerous and important, I mean to treat fully of them in this place. If any of these diseases arise from a gonorrhoea, they are most probably not the consequences of any specific quality in the venereal poison, but are such as might be produced by any common inflammation in those parts, as was observed of the continued symptoms. In this investigation we shall find some of the complaints arising out of each other, so that there is frequently a series of them. Thus a stricture of the urethra produces an irritable bladder, a frequent desire to make water, increased strength of the bladder, a dilatation of the urethra between the bladder and stricture, ulceration, fistulas in perinaso, dilatation of the ureters and enlargement of the pelvis of the kidneys, besides other complaints that are sympathetic, such as swellings of the testicle, and of the glands in the groin. I shall treat of the diseases of those parts in the order in which they most commonly arise. It may be observed that most of these diseases, especially the diminution of distensibility in the bladder, attack men advanced beyond the middle age, although many, if not all of them, are at times found in younger subjects, and the circumstances of their appearing at this period arises probably in some degree from a long habit of an unnatural mode of life producing many diseases, such as gout; for certainly such complaints do not so frequently take place among the more uncivilized nations. The most frequent disease in the urethra is an obstruction to the passage of the urine; it happens both in young and old, although most frequently in the latter. Before I begin to treat of this subject, I shall, for the better understanding of the whole, make some observations on the uses of this passage in its natural state. It may first be observed, that the urethra in man is employed for 100 HUNTER ON THE VENEREAL DISEASE. two purposes. On this occasion I may be allowed to make the following general remark, that nature has not been able to apply any one part to two uses with advantage, as might be illustrated in many instances in different animals. The animals whose legs are contrived both for swimming and walking, are not good at either, as seals, otters, ducks, and geese. The animals also whose legs are intended both for walking and flying, are but badly formed for either, as the bat. The same observations are applicable to fish, for the flying fish neither swims nor flies well; and whenever parts intended for such double functions are diseased, both are performed imperfectly. This is immediately applicable to the urethra, for it is intended as a canal or passage both for the urine and the semen. The urine requires the simplest of all canals, and of no greater length than the distance from the bladder to the external surface, as we find the urethra in women, birds, the amphibia, and fish; but the passage for the semen in the quadruped requires to be a complicated canal, and of a length capable of conveying the semen to the female, provided with many additional and necessary parts, as the corpus spongiosum urethras, musculi acceleratores, Cowper's glands, prostate gland, and vesiculas seminales. As all these parts are to serve the purposes of generation, and as the diseases of this canal are principally seated in them, we at once see how much the urinary organs must suffer from a connexion with parts so numerous and so liable to disease; and what adds to the evil is, that the actions of the urinary organs are constant, and absolutely necessary for the well-being of the machine, whereas the evacuation of the semen takes place only during a certain portion of life, is then only occasional, and never essentially necessary to the existence of the individual. The force of this observation is at once seen by making the comparison between the inconveniences that attend the expulsion of the urine in the male, and in the female. The canal of the urethra is liable to such diseases as are capable of preventing in some degree the passage of the urine through it; and in some of these diseases the passage at last becomes completely obstructed. In all cases there is a diminution of the size of the canal, but in different ways. There are five modes of obstruction, four of which are diseases of the passage itself, the fifth is a consequence of the diseases of other parts. Three of the former are a lessening of the diameter of the passage: the fourth an excrescence in the passage; the fifth arises from the sides being compressed, which may be done either by exterior contiguous swellings, or by a swelling of the prostate gland.

The three first I shall now consider, of which the first is the true permanent stricture arising from an alteration in the structure of a part of the urethra. The second is a mixed case, composed of a permanent stricture and spasm. The third is the tru- spas- OF THE PERMANENT STRICTURE. 101 modic stricture. Most obstructions to the passage of the urine, if not all, are attended with nearly the same symptoms, so that there are hardly sufficient marks for distinguishing the different causes. Few take notice of the first symptoms of a stricture till they have either become violent, or have been the cause of other inconveniences. For instance, a patient shall have a considerable stricture without observing that he does not make water freely; he shall even have, in consequence of a stricture, a tendency to inflammation, and suppuration in the perinasurn, and not feel any obstruction to the passage of his urine, nor suspect that he has any other complaint than the inflammation in the perinasurn. In all of these obstructions the stream of water becomes small, and that in proportion to the obstruction ; but this symptom, though probably it is the first, is not always observed by the patient. In some the water is voided only in drops, and then it cannot escape notice ; in others the stream of urine is forked or scattered : under such circumstances, the passage should be examined with a bougie ; and if one of a common size passes with tolerable ease, the fifth cause of obstruction is to be suspected, which will most probably be found to be a swelled prostate gland, for any other cause that can produce a compression of the sides of the urethra sufficient to obstruct the urine, will be known to the patient, such as a tumour forming anywhere along the canal, or an inflammation along its sides. If, therefore, neither of these is known to exist, the prostate gland should be examined, as will be described hereafter. The spasmodic obstruction will commonly explain itself when the symptoms are well investigated, for the obstruction arising from this cause will not be permanent. These obstructions, but more particularly that from a permanent stricture, are generally attended with a discharge of matter, or a gleet. This is often considered by the patient as the whole disease, and he applies to the surgeon for the cure of a gleet. The surgeon often perseveres in attempting the cure of this disease ; but, no success attending him, at last other symptoms are observed, and a stricture is suspected, either by the surgeon or patient. In diseases of this passage, and also of the prostate gland and bladder, there is commonly an uneasiness about the perinasurn, anus, and lower part of the abdomen, and the patient can hardly cross his legs without pain. CHAPTER II.

OF THE PERMANENT STRICTURE.

In the permanent stricture* the patient seldom complains till he can hardly procure a passage for the urine ; and frequently has a considerable degree of strangury, and even other symptoms that

* Vide Plate I. fig. 1. 10 102 HUNTER ON THE VENEREAL DISEASE. happen in stone and gravel, which are therefore too frequently supposed to be the causes of the complaint. The disease generally occupies no great length of the passage; at least, in most of the cases that I have seen, it extended no further in breadth than if the part had been surrounded with a piece of packthread, and in many it had a good deal of that appearance. I have, however, seen the urethra irregularly contracted for above an inch in length, owing to its coats or internal membrane being irregularly thickened, and forming a winding canal. A stricture does not arise in all cases from an equal contraction of the urethra all round, but in some from a contraction of one side, which probably has given the idea of its having arisen from an ulcer on that side. This contraction of one side only throws the passage to the opposite side, which often renders it difficult to pass the bougie. The contracted part is whiter than any other part of the urethra, and is harder in its consistence. In some few cases there are more strictures than one. I have seen half a dozen in one urethra, some of which were more contracted than others; and indeed many urethras that have a stricture have small tightnesses in other parts of them. This we learn from successive resistance felt in passing the bougie. Every part of the urethra is not equally subject to strictures, for there appears to be one part which is much more liable to them than the whole of the urethra besides, that is, about the bulbous part. We find them, however, sometimes on this side of the bulb, but very seldom beyond it. I never saw a stricture in that part of the urethra which passes through the prostate gland : and the bulb, besides being the most frequent seat of this disease, has likewise strictures formed there of the worst kind. They are generally slow in forming, it being often several years from their being perceived before they become very troublesome. The same stricture is not at all times equally bad, for we find that in warm weather it is not nearly so troublesome as in cold. These changes are often very quick. A cold day, even an hour of cold weather, shall produce a change in them ; and the same stricture is almost always worse in winter than in summer. However, this observation is not free from exceptions; I knew one case that was always worse in the summer. There are other circumstances besides cold that make a stricture worse. A gentleman who had an ague always found the stricture increased during the fit. It is also increased by drinking, violent exercise, and by the retention of urine afler an inclination to void it has been felt. This last cause is often so great as to produce a total stoppage for a time. It is sometimes rendered much worse by a small calculus passing from the bladder, of the formation of which this stricture was probably the cause. The calculus not passing, will produce a total stoppage of urine, the cause of which can hardly be known at the time, and if known it could not be remedied without an operation.* * Vide Plate III. OF THE PERMANENT STRICTURE. 103 It is impossible to say what is the cause of that alteration in the structure of the urethra which diminishes the canal: it has been ascribed to the effects of the venereal disease, and often to the method of cure. But I doubt very much if it commonly, or even ever, arises from these causes; yet as most men have had venereal complaints some time or other, it is natural to ascribe the stricture to them, and therefore it may be very difficult to refute this opinion. Many reasons, however, can be given why we should suppose that it is not commonly a consequence of a venereal inflammation. Strictures are common to most passages in the human body; they are often to be found in the oesophagus; in the intestines, especially the rectum; in the anus; in the prepuce, producing phimosis; in the lachrymal duct, producing the disease called fistula lachrymalis, where no disease had previously existed. They sometimes happen in the urethra where no venereal complaint has ever been. I have seen an instance of this kind in a young man of nineteen, who had the complaint for eight years, and which therefore began when he was only eleven years of age. It was treated at first as stone or gravel. He was of a scrofulous habit, the lips thick, the eyes sore, a thickened cornea of one eye, and the general habit weak. This stricture was in the usual place, about the membranous part of the urethra. I have seen an instance of a stricture in the urethra of a boy of four years, and a fistula in perinaso in consequence of it, They are as common to those who have had the gonorrhoea slightly as those who have had it violently. I knew a young gentleman who had a very bad stricture. He had had several gonorrhoeas, but they were so slight that they seldom lasted a week, nor in any of them did the pain extend beyond the frasnum; but the stricture was about the membranous part. Cases of this kind occur every day. They are never found to come on during the venereal inflammation, nor for some time after the infection is gone. There have been thirty, and sometimes forty, years between the cure of a gonorrhoea and the beginning of a stricture, the health being all that time perfectly good. If they arose in consequence of the venereal inflammation, we might expect to find them of some extent, because the venereal inflammation extends some way; and we should also expect to find them most frequent in that part of the urethra which is most commonly the seat of the venereal disease. But I remarked before, that they are not so frequent there as they are in other parts of the urethra. It is supposed by many that strictures arise from the use of injections in the cure of the gonorrhoea; but this opinion appears to be founded in prejudice, for I have seen as many strictures after gonorrhoeas that have been cured without injections as after those cured with them. Such modes of accountingfor strictures give no explanation of those where there has been no previous gonorrhoea, or where the gonorrhoea has not been cured by injections; and indeed if we consider the mode of cure of strictures, we must see that an injection is a mild application to the urethra compared to a bougie ; yet a bougie 104 HUNTER ON THE VENEREAL DISEASE. has never been supposed or known to be the cause of a stricture. Further, some have injected by mistake very irritating liquors,'such as the undiluted extract of lead, and caustic alkali, without giving the least tendency towards a stricture, although they produced violent inflammation and even sloughing of the internal membrane of the urethra. By many they have been supposed to have arisen from the healing of ulcers in the urethra; but as I never saw an ulcer in these parts, except in consequence of a stricture, and as I do not believe there ever is an ulcer in the case of a common gonorrhoea, I can hardly subscribe to that opinion.*

The bougie, with its application, is perhaps one of the greatest improvements in surgery which these last thirty or forty years have produced. When I compare the practice of the present day with what it was in the year 1750, I can scarcely be persuaded that I am treating the same disease. I remember when, about that time, I was attending the first hospitals in this city, the common

* [Many well-authenticated facts disprove the common prejudice which attributes stricture invariably to gonorrhoea or to the use of injections. But when the author goes so far as to question whether it ever arises from these causes, bis opinion is contradicted both by reason and by experience. It would appear that any irritation on the urethra, if sufficiently long continued, may give rise to stricture. It may be consequent on stone in the bladder, on disease of the prostate or disease of the bladder, on acid urine, on repeated attacks of strangury occasioned by the application of a series of blisters. But of all sources of irritation which can affect the urethra, the most common and the most severe is gonorrhoea, and hence a large proportion of cases of stricture follow so immediately on this disease as to be justly attributable to it. There are few cases of gonorrhoea in which the stream of urine is not diminished in size, from the existence of some degree of spasmodic contraction in the membranous portion of the canal. If the gonorrhoea lasts long, this spasm may become habitual, and terminate in stricture : and the likelihood of such a result is much increased if the inflammation is not confined to the extremity of the urethra, but extends to the bulb and neck of the bladder. How far injections have a tendency to produce the same effect is more doubtful. When they are successfully used on the first appearance of the discharge, it is probable that, by cutting short the disorder, they rather prevent than promote stricture. But where injections fail, they unquestionably in many cases extend the sphere of the inflammation, and involve those parts of the urethra which are in the vicinity of the bulb, and are especially liable to this affection. Again, the discharge, as the author has elsewhere observed, relieves the spasm of a stricture. In cases where there exists already spasmodic contraction of the urethra, injections, by diminishing or arresting the discharge, will undoubtedly tend to increase the spasm and to render it permanent. The old opinion was, that a stricture was the cicatrix of an ulcer which existed during a gonorrhoea. This notion the author justly repudiates. But he must not be understood'to mean that ulceration may not sometimes arise from other causes, and leave behind it a stricture. When the urethra has been lacerated by external violence, as by a blow on the perinaeum, stricture will usually follow, and will in most cases be of a kind which is peculiarly intractable and obstinate.] OF THE PERMANENT STRICTURE. 105 bougies were either a piece of lead,* or a small wax candle ; and although the present bougie was known then, yet a due preference was not given to it, or its particular merit understood, as we may see from the publications of that time. Daran was the first who improved the bougie and brought it into general use. He wrote professedly on the diseases for which it is a cure, and also of the manner of preparing it; but he has introduced so much absurdity in his descriptions of the diseases, the modes of treatment, and of the powers and composition of his bougies, as to create disgust. However, this absurdity has been much more effectual in introducing the bougie into universal use than all the real knowledge of that time, directed by good sense, could have been. Such extravagant recommendations of particular remedies are not at all times without their use. Inoculation would have still been practised with caution had it not been for the enthusiasm of the Suttons. Preparations of lead would not have been so universally applied if they had not been recommended by Goulard in the most extravagant terms; nor would the hemlock have come into such general use if its true merits only had been held forth. Improvements are often over-rated, but they come to their true value at last. Sutton has told us, that the cold regimen, in extreme, is infinitely better than the old method ; but from genera] practice we have learned that moderation is best, which is all we yet know. When Daran published his observations on the bougie, every surgeon set to work to discover the composition, and each conceived that he had found it out, from the bougies he had made producing the effects described by Daran. It never occurred to them that any extraneous body, of the same shape and consistence, would do the same thing.

§ 2. Of the Treatment of the Permanent Stricture.

The cure of the permanent stricture is, I believe, to be accomplished only by local applications. Mercury has been given, upon the erroneous supposition of its being venereal, but without success. The cure is either a dilatation of the contracted part, or a destruction of it by ulceration, or escharotics. The dilatation is performed by the bougie, and this is seldom or never more than a temporary cure; for although the passage may be dilated sufficiently for the urine to pass, yet there is always the original tendency to contraction, which generally recurs sooner or later.f The ulcerative pro-

* When lead was used in place of bougies it has happened that a piece of the end has broken off in the bladder, which has been dissolved by injecting quicksilver. I at first suspected that quicksilver could not come in contact with lead while in water, so as to dissolve it; but upon making the experiment I found it succeeded. f In cases of stricture, when a patient applies for relief, it may often be proper to inquire into the history of the case previous to the passing of a bougie, espe- 10* 106 HUNTER ON THE VENEREAL DISEASE. cess is also effected by a bougie, and the destruction by escharotics is by means of caustics. It often happens in strictures that the passage is so diminished as hardly to allow any water to pass, producing often a total stoppage; nor will a bougie immediately pass; and if it can be made to pass, yet no water follows it when withdrawn. In such cases therefore we must have recourse to the means that afford a temporary relief, such as the warm bath, which counteracts the effects of cold, and quiets any spasms that may have taken place in the parts, and clysters with opium, which have still more effect. Producing an evacuation by stool often lessens the spasm, for a spasmodic suppression of urine frequently arises from a constipation, even where there is no stricture. The cure by dilatation is, I imagine, principally mechanical when performed by bougies, the powers of which are in general those of a wedge. However, the ultimate effect of them is not always so simple as that of a wedge upon inanimate matter, for pressure produces action of the animal powers, either to adapt the parts to their new position, or to recede by ulceration, which gives us two very different effects of a bougie, and of course two different intentions in applying them ; one to produce dilatation, the other ulceration, which last is not always so readily effected. It generally happens, as has been already observed, that the disease has gone considerable lengths before application has been made for a cure, and therefore the stricture has become considerable, in so much that it is often with great difficulty that a small bougie can be made to pass. If the case is such as will readily admit the end of a small bougie to pass, let it be ever so small, the cure is then in our power. It often happens, however, that the stricture is such as will resist the passing of a small bougie at first, and even after repeated trials. Yet it is necessary to persevere with the small bougie, for sometimes it happens that the passage through the stricture is not in a line with the urethra itself, which of course obstructs the bougie; such strictures, I suspect, are not equally placed all round, so as to throw the small passage remaining into the centre of the canal. In many cases, where the stricture is very considerable, much trouble is given by occasional spasms, which will either resist the bougie altogether, or only let a very small one pass, though at another time they will admit one larger. In such cases I have been able to get the point of the bougie sometimes to enter, by rubbing the perinasurn externally with the finger of one hand while I

cially to inquire if he ever used bougies before ; if he has, then to inquire into the result; if they passed readily, or if they did not pass the stricture at all : if the first, then nothing further need be asked : but if the last, then to inquire if he or his surgeon observed that they were gaining ground with the bougie, viz , if the bougie went further in before it was left off than at first; if so, then to ask him how far. If they have visibly gained ground without getting through the stricture, I am afraid that the use of the bougie must not be pursued, because it is m^st probable that a new passage has been formed, which makes the passing of the bougie into the stricture impossible. OF THE PERMANENT STRICTURE. 107 pushed the bougie on with the other. This, though it does not always succeed, yet is worth the trial. Whether it alters the position of the stricture, so as to give entrance to the point of the bougie, or by sympathy removes the spasm, I will not absolutely determine, but 1 believe it rather acts by sympathy. In such cases of spasm in the stricture, I have often succeeded by letting the bougie remain a little while close to the stricture, and then pushing it on ; this mode so often succeeds, that it should always be attempted when the bougie does not pass, or only passes occasionally. This will be mentioned more fully when we shall consider the spasmodic stricture. The spasm may probably be taken off by dipping the glans penis into cold water, which succeeds sometimes in the common strangury ; but this cannot be so easily done while a bougie is in the passage. In cases of a permanent stricture, though the bougie does not at first pass, yet, after repeated trials, it will every now and then find its way, which helps to render a future trial more certain and easy. It, however, too often happens that the future success does not immediately depend upon passing the bougie once or twice, for it shall pass to-day and not to-morrow; and this uncertainty shall last for weeks, notwithstanding every trial we can make; yet I may observe, that in general its introduction becomes gradually less difficult, and therefore in no case should we despair of success. It is imagined by some that the best time for trial in these cases is just after making water, as the passage is supposed to be clear, and more in a straight line; but this is not confirmed by practice. It is not an easy matter, in cases where the passage is very small, to know whether the bougie has entered the stricture or not, for such slender bougies as must generally be used at first bend so very easily, that the introducer is apt to think it is passing* while it is only bending. A surgeon, however, should in general first make himself acquainted with the situation of the stricture, by a commonsized bougie, and afterwards make use of a smaller one, and when he comes to the stricture, push gently, and for a little time only. If the bougie has passed further into the penis, he will know how far it has entered the stricture by taking off the pressure from the bougie, for if it recoil he may be sure that it has not passed, at least has not passed far, but only bent; for the natural elasticity of the bougie, and the direction of the passage having been altered by it, will force it back again. But if it remain fixed, and do not recoil, he may be sure that it has entered the stricture. In using a very small bougie, however, these observations are not so applicable, for it may be bending, or bent, without being perceptible. It often happens that a bougie will enter only a little way, perhaps not more than one-tenth of an inch, and then bend if the pressure be continued. To determine whether this be the case, it is necessary to withdraw the bougie and examine its end; if the end be blunted, we may be sure the bougie has not entered in the 108 HUNTER ON THE VENEREAL DISEASE.

least; but if it be flattened for an eighth or tenth of an inch, or grooved, or have its outer waxy coat pushed up for that length; or if there be a circular impression made upon the bougie where the stricture is, or only a dent on one side, both of which last I suspect arise from spasm at the time, we may then be sure that it has passed as far as these appearances extend. It becomes then necessary to introduce another exactly of the same size, and in the same manner, and to let it remain as long as the patient can bear it, or convenience will allow ; and by repeating this we may overcome the stricture. Sometimes we can judge of its having entered the stricture, by pulling it gently out; for if it stick a little at the first pull, wre may be certain it has entered; but the appearance of the bougie itself will give the best information.* In such cases I have always directed my patient to preserve the bougie for my inspection, exactly in the same form it was when it was withdrawn. But when it passes with ease this nicety is not necessary. The time that each bougie ought to remain in the passage must be determined by the feelings of the patient; for it should never give pain, if possible. To go beyond this point is to destroy the intention, to increase the very symptoms that are meant to be relieved, and to produce irritation, which for a time renders the further application of the bougie improper. While the bougie is passing, if the patient feel very acutely, it should not be left in the urethra above five or at most ten minutes, or not so long if it give great pain; and each time of application should be lengthened so gradually as to be insensible to the feelings of the patient and the irritability of the parts. I have known it days, nay, in many patients, weeks, before they could allow the bougie to remain in the passage ten or even five minutes, and yet in time they have been able to bear it for hours, and at last without any difficulty. The best time to let it remain in the passage is when the patient has least to do; or in the morning, while he is in bed, provided he can introduce it himself. The bougie should be increased in size according to the facility with which the stricture dilates, and the ease with which the patient bears the dilatation. If the parts are very firm or very irritable, the increase of the size of the bougie should be slow, gradually stealing upon the parts, and allowing them to adapt their structure

* It may be remarked that there are some lacunae (vide plate I. fig. 2.) near and also a little way from the glans penis, which often stop the bougie, and give at first the idea of a stricture. I have known them taken for such ; and when the bougie stops so near to the glans this is to be suspected, and therefore we should vary the direction of the point of the bougie, bearing it against the under side of the urethra. When the bougie stops in one of those lacunae, I think that the patient appears to have more pain than from a real stricture. The valvular part of the prostate "gland formed by disease, (vide plate IV.) very often obstructs the bougie, and is taken for a stricture by those who are not well acquainted with the different obstructions in this canal; and by those who are, it is a means of discovering disease in this part; and indeed in a natural state of parts I think I can ascertain when I come to this part with a bougie. OF THE PERMANENT STRICTURE. 109 to the increased size. But if the sensibility of the parts will allow of it, the increase of the size of the bougie may be somewhat quicker, though never more quick than the patient can bear with ease. The increase should be continued till a bougie of the largest size passes freely; nor should this be laid aside till after three weeks or a month, in order to habituate the dilated part to its new position, or to take off the habit of contracting from the part as much as possible. But, as was observed before, the permanency of this cure can seldom be depended upon. Instead of proceeding with the caution recommended, it has been practised with success for a time to force a common-sized bougie through a stricture that only allowed a small one to pass. This, I suppose, either tore the stricture or weakened it by stretching it suddenly so as to render it unable to recover its contractile power for a considerable time after. I have seen where this has produced good effects, and for a time removed the permanent stricture and prevented spasm. This is a practice, however, which I have never tried, having always preferred the mild treatment where I could pass a bougie. I have known the passing of the bougie remove, almost immediately, a swelling of the testicle, which had arisen from the stricture ; therefore such a symptom should not prevent the use of the bougie. . . In cases of strictures where the bougie is used, the patient is commonly in other respects well, and is with difficulty persuaded to restrain from his common habits, often making too free in eating, drinking, and exercise; which are all in many cases pernicious, more especially where inflammation and suppuration have taken place. It is, therefore, the duty of the surgeon to restrict the patient for some time within certain bounds, till he finds by trials what the parts are capable of bearing without producing inflammation.

^ 3. Of the Cure of Stricture by Ulceration.

The cure of a stricture by means of ulceration is likewise effected by a bougie. This method may be employed both in cases where a bougie will and where it will not pass. In the first case there is not the same necessity for ulceration as in the second, because where a bougie will pass there is no immediate danger arising from the stricture, which may therefore be dilated, as has been already described. But if this method should be preferred to a slow dilatation, which allows the parts time to adapt themselves to their new position, the stricture may be destroyed by producing ulceration in the parts, especially if they are not irritable, but admit of considerable violence. . When this is intended, the bougie should be introduced as far into the stricture as possible, and the size of it increased as fast, as the sensations of the patient can well bear. This will produce ulceration in the part pressed, which is a more lasting cure, because more 110 HUNTER ON THE VENEREAL DISEASE.

of the stricture is destroyed than when the parts are simply dilated. I believe, however, there are few patients that will submit to this practice, and indeed few will be able to bear it; for I have seen it bring on violent spasms in the part, which have produced suppression of urine, and proved very troublesome. Therefore as there is no absolute necessity in such cases for pursuing this method, I do not recommend it as a general practice, although there have been cases in which it has succeeded. Where this method is to be practised, it might probably be right to accustom the passage to a bougie for some time before such violence is used. If the smallest bougie which can possibly be made cannot be made to pass by some degree of force, dilatation becomes impracticable, and it is necessary that something else should be done for the relief of the patient; for the destruction of the stricture must be effected. In many cases it may be proper to attempt this by ulceration of the part; for we find from experience that a stricture may be removed by the simple pressure of a bougie. This effect must arise from the irritation of absorption being given to the diseased part, which, from the stricture not being an originally-formed part, nor having any power of resistance equal to the original one, is more susceptible of ulceration, and thereby is absorbed. The bougies, which are only to produce ulceration in consequence of their being applied to the stricture, need not be so small as in the former cases, as they are not intended to pass; and by being of a common size they will also be more certain in their application to the stricture. The force applied to a bougie in this case should not be great: for a stricture is the hardest part of the urethra; and if a bougie is applied with a considerable degree of pressure, and left in the passage, it sometimes happens that the end of it slips off the stricture before there is time for ulceration, and makes its way into the substance of the corpus spongiosum by the side of the stricture; and if the pressure be continued still longer, it will make a new passage beyond the stricture in the corpus spongiosum urethras/ This more readily happens if the stricture be in the bend of the canal, as in such cases the bougie can hardly be applied exactly to it, not having the same curve. Such mischief I have seen more than once ; and sometimes the bougie has been pushed so far as to make its way into the rectum. It often requires a considerable time before the whole is so far ulcerated as to admit the bougie, and this tires the patient and almost makes him despair of a cure. In this process great attention should be paid to the seeming progress of the cure; for if it appears to the surgeon that he is gaining ground by the bougie passing further in, and yet the patient does not make water better in the least, then he may be sure that he is forcing a new passage-!

* Vide plate II. f This makes it necessary in all cases of strictures where bougies will not pass to be very particular in our inquiries whether th« patient has used bougies formerly, and whether there may not be reason to believe that they had taken a wrong direction. OF THE PERMANENT STRICTURE. Ill When the stricture has so far yielded to these means as to admit a small bougie, the dilatation is to be made as in the former case where a bougie passed at first. Whenever a bougie of a tolerable size passes with ease, and the parts and patient have become accustomed to it, it is no longer necessary that the surgeon should continue to pass it: the patient may be allowed to introduce bougies himself; and when he can do it readily the business may be trusted to him, as he can make use of them at the most convenient times, so that they may be applied longer at a time and oftener, the surgeon only attending occasionally. This practice of the patient under a surgeon's eye, by which he is taught how to pass them, becomes more necessary, as strictures are diseases that commonly recur; and therefore no man, who has ever had a stricture, and is cured of it, should rely on the cure as lasting, but should be always prepared for a return; and should always have some bougies by him. He should not go a journey, even of a week, without them; and the number should be according to the time he is to be absent, or to the place whither he is going, for in many parts of the world he cannot be supplied with them. The bougies for such purpose should be of different sizes, as it is uncertain in what degree the disease may return. Bougies, in all cases, from their shape and from the action of the parts, readily slip out, whereby the cure is retarded ; but it is much worse when they pass into the bladder, which can only take place in cases where the stricture is in some measure overcome. The consequence of a bougie passing into the bladder must at once appear in its fullest force to everyone : it subjects the patient in most cases to be cut as for the stone; and indeed if it is either not soon thrown out or cut out it becomes the basis of a stone. A young man was cut for a bougie only a fortnight after it had passed into the bladder, and it was almost wholly crusted over with calculous matter. Bougies have been known to be forced out of the bladder along with the water by the action of that viscus, and in several folds. It is probable that the bladder in a natural state has not power sufficient to perform such an action; but we shall show that in cases of strictures where the resistance to the passing of the water is very much increased, the strength of the bladder becomes proportionably greater. This happens principally in strictures of long standing. Such accidents are often observed before the outer end of the bougie has got beyond the projecting part of the penis, but even then it is difficult of extraction. I have succeeded in some of these cases by fixing the bougie in the urethra some way below its end : for instance, in the perinasurn, by pressing against it with one hand, and pushing back the penis upon the bougie with the other hand ; then laying hold of the penis upon the bougie, removing the pressure below, and drawing the whole up; and, by performing these two motions alternately, I have been able to lay hold of the end of it. However, this does not always succeed; for when the bougie is either small, or becomes soft, it will not admit of the penis 112 HUNTER ON THE VENEREAL DISEASE. being pushed down upon it without bending; or if the thick end of the bougie has got beyond the moveable or projecting part of the penis, then this mode of treatment becomes impracticable. I have succeeded in these last cases with the forceps for extracting the stone out of the urethra; but if it has got into the bend of the urethra, this practice will also fail; and in such a state it would be most advisable to pass a catheter down to it, and cut upon that; and probably the above-mentioned forceps, introduced through the wound, might then lay hold of its end ; or by cutting a little further, so as to expose some part of the bougie, it might be easily extracted, without the necessity of cutting into the bladder. This part of the operation, however, would be very difficult in a fat or lusty man. To prevent the inconveniency of the bougie coming out or the mischief of its passing in, it is necessary to tie a soft cotton thread round that end of the bougie which is out of the urethra, and then round the root of the glans. This last part should be very loose, for an obvious reason ; and the projecting part of the bougie should also be bent down upon the penis, which makes it both less troublesome and more secure.

§ 4. Of the Application of a Caustic to Strictures.

When a bougie can readily pass, there is no necessity for using any other method to remove the stricture; but there are too many cases where a bougie cannot be made to pass, or so seldom that it cannot be depended upon for a cure. This may arise from several causes. First, the stricture may be so tight as not to allow the smallest bougie to pass. Secondly, the orifice in the stricture may not be in a line with the urethra, which will make it uncertain, if not impossible, to pass a bougie. Thirdly, there may be no passage at all, it having been obliterated by disease, and the urine discharged by fistulas in perinaso. The first very rarely occurs : for if the passage in the stricture be in a line with the general canal, a small bougie will commonly pass ; and, although it may not readily do so upon every trial, it will be sufficient to make way for another bougie, which is all that is wranted. The second case, where the canal is not in a line with the common passage, may arise from three causes. First, when the stricture is in the bend of the urethra, although the passage through it may be in the centre of the canal, yet as the bougie cannot have the exact curve, it will be very uncertain in its application. Secondly, from an irregularity in the formation of the stricture, which may throw the passage to one side, even in the straight part of the urethra ; and thirdly, from ulceration having taken place, producing fistulas in perinaso, which often make the canal irregular in its course. The third case where the application of the caustic may be necessary is where there is no passage at all, which happens from OF THE PERMANENT STRICTURE. 113 ulceration and abscesses in the perinasurn opening externally; and in the healing of them the passage is often closed up entirely. In all the above-mentioned cases I have succeeded with the caustic beyond expectation. If the obstructions are anywhere between the membranous part of the urethra and the glans, where the canal is nearly straight, or can easily be made so by the introduction of a straight instrument, it becomes an easy matter to destroy them by caustic; but if beyond that, it becomes then more difficult. However, at the beginning of the bend of the urethra the obstruction may be so far removed as to admit of the passing of a bougie, or at least to procure a tolerably free passage for the urine. I have seen several cases where it was thought necessary to follow this practice; and it succeeded so well that after a few touches with the caustic the bougie could be passed, which is all that is wanted. The success in these cases was such as would incline me to have recourse to this practice very early ; indeed whenever I could not pass a small bougie through the stricture. I look upon the caustic as a much safer method than using pressure with a bougie, for the reason before mentioned, that is, on account of the danger of making a new passage, without destroying in the least any part of the obstruction. Most of the strictures which I have examined after death appeared to have been in the power of such treatment. However, I have seen one or two cases where the contraction was of some length and irregular, which would have puzzled me if I had attempted the cure with the caustic; because I should have been apt to suspect that I was making a new passage by my gaining ground, and yet not relieving the patient by the removal of the symptoms. I have often tried this practice in strictures where there were also fistulas in the urethra, and where the water came through different passages. Such cases were not the most favourable ; yet I succeeded in the greater part of them, that is, I overcame the stricture and could pass a bougie freely. I have seen several cases of fistulas of these parts, where the natural passage was obliterated by the stricture, in which I have succeeded with the caustic, and the fistulous orifices have readily healed. It does not happen always in cases of obstruction to the passage of the urine, that when the obstruction is removed by the caustic, and the water of course passes freely, a bougie will also pass. This, I apprehend, arises from the caustic not having destroyed the stricture in a direct line with the urethra, so as to allow a bougie to catch the sound urethra beyond. But this appears to me of little consequence, as it is as much in the power of the bougie to prevent a return at this part as if it had passed on to the bladder ; for if the water flows readily it is certain that the caustic has gone beyond the stricture, although it may not be in the direct line, and that the only risk of a return of obstruction will be at the old stricture ; but as a bougie can now pass beyond that part it does as much good as if it passed into the bladder; for I have known several cases 114 HUNTER ON THE VENEREAL DISEASE. where the bougie appeared to have the same effect as if it had passed on to the bladder. The application of the caustic need not be longer than a minute, and it may be repeated every day, or every other day, allowing time for the slough to come off. But there are other causes that may prevent the repetition of the caustic, besides waiting for the separation of the slough ; for sometimes the use of it brings on irritation, inflammation, or spasm in the part, which frequently occasions a suppression of urine for a time, against which all the means used commonly on such occasions to procure relief must be employed, and we must wait till these symptoms are gone off. If the patient can make water immediately after the application it will be proper, as it will wash away any caustic that may have been dissolved in the passage, which if left would irritate the parts. A little water injected into the urethra will answrer the same purpose. About the year 1752 I attended a chimney-sweeper labouring under a stricture. He was the first patient I ever had under this disease. Not finding that I gained any advantage after six months' trial with the bougie, I conceived that I might be able to destroy the stricture by escharotics ;* and my first attempt was with red precipitate. I applied to the end of a bougie some salve, and then dipped it into red precipitate. This bougie I passed down to the stricture; but I found that it brought on considerable inflammation all along the inside of the passage, which I attributed to the precipitate being rubbed off in passing the bougie. I then introduced a silver canula down to the stricture, and through this canula passed the bougie with precipitate as before. Not finding, however, that the patient made water any better, and not as yet being able to pass the smallest bougie through the stricture, I suspected that the precipitate had not sufficient powrers to destroy it. I therefore took a small piece of lunar caustic, and fastened it on the end of a wire with sealing-wax, and introduced it through the canula to the stricture. After having done this three times, at tw^o days' interval, I found that the man voided his urine much more freely. Upon the application of the caustic a fourth time, my canula went through the stricture, f A bougie was afterwards passed for some little time till he was perfectly well. Having succeeded so well in this case, I was encouraged to apply my mind to the invention of some instrument belter suited to the purpose than the before-mentioned, which I have in some degree effected, although it is not yet perfectly adapted to all the situations of stricture in the urethra. The caustic should be prevented from hurting any other part of the canal; which is best done bv introducing it through a canula to the stricture, making it protrude a little beyond the end of the canula, by which it acts only upon the stricture. The caustic should be fixed in a small portcrayon. It * Having lately looked over some authors on this disease, I find that this is not a new idea. t Wiseman had the same idea, but probably the clumsy way in which he attempted to put it in execution might be the reason why he seems not to have pursued it. OF THE PERMANENT STRICTURE. 115 is necessary to have a piece of silver of the length of the canula, with a ring at one end, and a button at the other of the same diameter with the canula, forming a kind of plug, which should project beyond the end of the canula that enters the urethra, by which means it makes a rounded end; or the portcrayon may be formed with this button at the other end. The button being introduced into the canula, it should be passed into the urethra, and when it reaches the stricture the silver plug should be withdrawn, and the portcrayon with the caustic introduced in its place; or, if the plug and portcrayon are on the same instrument, then it is only withdrawing the plug, and introducing the portcrayon with the caustic. This plug, besides giving a smooth rounded edge to the canula answers another good purpose, by preventing the canula from be ing filled with the mucus of the urethra as it passes along, which mucus would be collected in the end of it, dissolve the caustic too soon, and hinder its application to the stricture.* If the stricture be in the bend of the urethra the canula may be bent at the end also; but it becomes more difficult to introduce a piece of caustic through such a canula, for the plug and portcrayon must also be bent at the end, which cannot be made to pass through the straight part of the canula; but this I have in some measure obviated by having the canula made flexible, except at the end where it is to take the curve.f After the bougie can be made to pass, the case is to be treated as a common stricture, either by dilating it slowly, or by quickly increasing the size of tho Lougio, and thue continuing the ulceration. There are sometimes more strictures than one; but it seldom happens that they are equally strong. One only becomes the object of our attention. The smaller ones may, however, be sufficient to hinder the passing the canula to that which is to be destroyed by the caustic. When that is the case, those small strictures are to be dilated with bougies, as in common, till they are sufficiently large to allow the canula to pass.J §

* Vide Plate 11. fig. 2 f Vide Plate II. fig. 3 and 4. X Added: "A. B., a soldier in the 16th regiment of light dragoons, had a stricture twenty years ago, and was in St. Thomas's Hospital : bougies were passed, and he got pretty well. About eight years afterwards the stricture began to recur, and has been growing worse ever since, and for these two years past he has not been able to do his duty, the water only coming from him in drops. In this state he applied to me. Finding the smallest bougie could not be made to pass, I desired that a full-sized one might be passed down to the stricture, and its end pressed against it, for as long a time and as often as he could bear with tolerable ease, and to continue this practice for some weeks. This he did without any advantage. Being now afraid of a total stoppage of urine without the common means of relief, and there being a sensation in the perinaeum threatening inflammation, I resolved to use the caustic. I applied it three times in the whole, at two days' interval ; and after the last application, he told me he had made water much more freely and less frequently than before. I introduced a bougie of the second or third size above the smallest, and it passed the stricture with great ease into the bladder. I then ordered him to pass the bougie, and increase it gradually till he could use the largest, which he did ; and he is now perfectly well."— Home. § [Since the time when Mr. Hunter wrote, the use of caustic in the cure of 116 HUNTER ON THE VENEREAL DISEASE. CHAPTER III.

Obstructions to the urine in women, I believe, generally arise from stricture, although not always; for I have known them prostricture has been greatly extended, chiefly through the labours of Sir E. Home, whose valuable work on strictures in the urethra and oesophagus should be consulted by all who wish to be acquainted with its various effects in detail. The mode of applying the caustic has been greatly improved. The use of the canula has been discarded, and an armed bougie has been substituted in its place ; that is, a small piece of nitrate of silver has been let into a common bougie, in such a manner as to present only on the surface of the extremity, and to be encircled on all sides by the plaster of which the bougie is composed. This instrument can be applied with far greater accuracy than the canula; the bougie can with ease be adapted to the curvature of the urethra, and the sides of the canal are protected from the action of the caustic. It appears that this contrivance was invented by Mr. Hunter himself, who employed it many years before his death in preference to that which he has detailed in this work. When it is intended to apply the caustic, it is necessary in the first instance to pass down to the stricture a common bougie, of such a size as moderately to fill the passage, and composed of such soft materials as readily to receive the impression of the part against which it is pressed. By first introducing this bougie, and keeping it for the space of a minute pressed against the stricture, the surgeon obtains several advantages. The urethra is opened, and the subsequent passage of the armed bougie rendered more easy and rapid; the exact distance of the stricture from the ortnce is ascertained ; and such a cast is taken of the stricture as to show accurately its size and shape, and to ascertain what effect has been produced by previous applications of the caustic. This information is so necessary that without it the treatment by caustic could not be pursued. The destruction of the disease is frequently partial and irregular. The armed bougie, notwithstanding every precaution, is sometimes not applied accurately on the orifice, or the caustic is dissolved in the moisture of the passage, and runs down to the lower part of the urethra, leaving the upper part almost untouched. These deviations must be accurately ascertained, in order that they may be corrected in subsequent applications. After this previous step, the armed bougie is to be introduced, the distance of the stricture having been first marked upon it. It should be of such a size as to fill the urethra, and should be pressed against the part for the space of a quarter of a minute or more. The time should be partly regulated by the sensations of the patient. As soon as a burning pain begins to be felt, it should be withdrawn. The use of the caustic should not be repeated oftener than every third or fourth day, since that interval must be allowed for the separation of the slough. The effects of caustic on strictures have been found in practice to be somewhat different from those which were anticipated by its first proposers. Its first and great effect is the relief of spasm. The morbid irritability of the part is exhausted by the violence of the stimulus. When the contraction is merely spasmodic, it is in most instances entirely removed by one or two applications. All difficulty of voiding the urine then disappears, and a full-sized bougie can be passed readily into the bladder. When there is a permanent stricture which is more or less affected with spasm, the spasm will be relieved as speedily, but the permanent contraction will remain. The stricture will not be removed, but its irritability will be lessened. The opening will be enlarged so as to admit a larger instrument than before, but it will not be dilated to the natural size of the urethra. These effects are obtained by one or two applications of the caustic as perfectly OF STRICTURES IN WOMEN. 117 duced by compression from some adjacent swelling, and they are common in uterogestation, as also in dropsical or scirrhous ovaria. But such causes are commonly known long before this effect is produced, by which the suppression is easily accounted for. It may also arise from excrescences as in men. How far a stricture in the urethra of this sex is really a consequence of a venereal inflammation T am not certain: but 1 should suppose it is not, and for stronger reasons still than those which I gave in speaking of the cause of strictures in men; for I can say that none of the strictures that I have seen in women have arisen in consequence of this disease, at least I had no reason to believe that they did ; and I have observed before that in most women who have the venereal disease in the form of a gonorrhoea, it seldom attacks the urethra. Therefore, if we find a stricture in a woman who has had the disease, we are not to impute it to that, at least till we can ascertain the urethra was affected ; and even then it will remain doubtful. Strictures are not near so common in women as in men. This may be owing to the great difference in the length of the two canals; but more especially to the canal in women being more simple, and intended only for one purpose. The stricture in women does not produce such a variety of symptoms, or so much mischief, as in men, there not being so many parts to be affected.

as by a longer continuance of its use. The actual destruction of the stricture is a very slow process, and in old indurated strictures is scarcely attainable. The slough which is produced by the nitrate of silver is very superficial, and no material destruction can be effected without numerous repetitions of the remedy. In the mean time there is much danger of deviating from the true direction of the urethra, and the patient is subject to very serious accidents during the course. Of these accidents the first is retention of urine, which is a very common consequence of caustic. It arises sometimes from the violence of the irritation, but at other times it appears to be derived from the obstruction which is given by the slough, which during the process of suppuration hangs like a fringe from the edge of the stricture, and where the opening is small seems to oppose a mechanical obstacle to the flow of the urine. Hemorrhage is another effect which is of frequent occurrence, and often proceeds to a most formidable extent. This symptom, however, though very alarming to the patient, is never fatal, and as it invariably facilitates the cure, it can scarcely be considered as undesirable. Again, caustic very frequently occasions rigors, especially in those who have previously suffered from them ; and it is by no means rare that its use should be followed by the occurrence of an abscess in the perinaeum. Moreover, caustic has no advantage over bougies in respect to the permanent cure of the malady. Experience has fully proved that after a stricture has been removed by caustic, bougies are still necessary, and that unless they are occasionally passed it is almost certain to recur. For these reasons the treatment by caustic has of late lost much of its former celebrity. Even those advantages which in some cases it unquestionably possesses have been insufficient to prevent it from falling more and more into disuse. Surgeons now generally prefer the treatment by bougies, which effects the same objects, sometimes indeed more slowly, but on the whole more certainly, and with less inconvenience and hazard.] 11* 118 HUNTER ON THE VENEREAL DISEASE. § 1. Of the Cure of Strictures in Women.

The cure of strictures in the urethra of women is similar to that in men; but it is rather more simple, from the simplicity of the parts. There is, however, an inconvenience attending the passing the bougie in women that does not occur in men, which is, that in most cases it must be passed for them, it being hardly possible for a woman to introduce a bougie herself. The confinement of the bougie is also more difficult; for although it can easily be prevented from going into the bladder by bending the outer end down upon the mouth of the vagina, yet it is very difficult to prevent it from slipping out. It will be necessary to have a bandage of the T kind passing down between the labia over the bend of the bougie. It appears to me that the caustic would answer extremely well in such cases; and therefore I should prefer it to the bougie, both for convenience and efficacy.

§ 2. Of the Gleet in consequence of Stricture.

I have already observed that it happens generally, if not always, that there is a gleet when there is a stricture in the urethra. This I suppose to arise from the irritation produced in the urethra beyond the stricture, by the urine in its passage distending this part too much, which distention is increased by the increased strength of the bladder. This symptom often leads us to the knowledge of a stricture, or at least gives a suspicion of such disease; and when a stricture is known to be the cause, no attempts should be made to cure the gleet, for it is generally cured when the stricture is removed ; but if it still remains, it may be cured in the manner recommended in common gleet, as probably arising from a cause different from stricture. CHAPTER IV.

OF STRICTURE ATTENDED WITH SPASMODIC AFFECTION.

There are very few strictures that are not more or less attended with spasms ; but some much more than others, the spasm being in some cases more the disease than the stricture itself. But real strictures are attended with occasional contractions, which make the passing of the urine much more difficult at one time than another. In all the cases that I have seen of this kind, when not attended with spasms the disease is not formidable; but w hen the parts are in a spasmodic state the symptoms are as violent as in the simple stricture. STRICTURE ATTENDED WITH SPASMODIC AFFECTION, ng

As this is a mixed case, it has all the characters both of the permanent and spasmodic stricture; for the urethra in such circumstances is in a state similar to what it is in the true spasmodic kind, being very irritable, giving great pain in the passing of the bougie, and often rejecting it altogether; as will be taken notice of when we shall treat of that disease. Upon considering this subject, we should at first hardly be disposed to believe that the spasm in the urethra is in the strictured part, which can scarcely be supposed capable of contraction; and it might therefore naturally be referred to the sound part of the urethra, as being brought on by the waters not flowing freely. If this is a just mode of accounting for it, we must suppose that the contraction is behind the stricture, that being the only part dilated by the water; and such urethras being very irritable, that part may contract so as to stop the flowing of the water altogether. But some circumstances that occur in practice give reason to believe that such strictures have the power of contraction; for we find the bougie grasped by the stricture when allowed to remain some time, and the circumstance of the strictured parts refusing the bougie at times is also a proof of the same. There is sometimes this singular circumstance attending these cases, that when there arises a gonorrhoea, or any other discharge of matter from the urethra, or an increase of an old gleet, the passage becomes free and allows the urine to pass as usual; but such relief is uncertain and only temporary, for whenever the discharge ceases the spasmodic affection returns. I think it is probable that it is only the spasm that is affected by the discharge, and not the real stricture. Two remarkable cases of this kind fell under my observation, which I shall now relate. A gentleman had for a long time a complaint in the urethra, attended with a stricture, which was supposed to be originally from a venereal complaint. It was often attended with a discharge, which always produced a slight fever on its coming on ; but while the discharge lasted the difficulty of making water was relieved, and that in proportion to the greatness of the discharge; and whenever he got a fresh gonorrhoea the same thing happened. Another gentleman had a difficulty in making water, supposed to arise from a stricture. It was generally attended with such a running as is common to strictures ; but when that discharge was much increased then the stricture was less in proportion. During this complaint he contracted two different infections, both of which relieved him of the stricture for the time. As this is a mixed disease, it may be thought proper to treat it with a bougie for the real stricture, and for the other to use the method to be recommended hereafter for the cure of spasm. It sometimes happens in these mixed kinds that a bougie does not immediately pass, but is rejected by the spasm; but by letting it lie in the urethra, almost close to the stricture, for ten, fifteen, or twenty minutes, you will often make it pass. This is as it were steal- 120 HUNTER ON THE VENEREAL DISEASE. ing upon it, and the water will often flow although the bougie is not attempted to be passed on. It is often relieved by gently irritating injections.* CHAPTER V.

OF SOME CIRCUMSTANCES ATTENDING THE USE OF BOUGIES; THEIR FIGURE AND COMPOSITION.

In cases of strictures, where a bougie is used as a wTedge, not as a stimulant, and where a stricture is so far overcome as to let a bougie pass on, the question is whether it may be better to pass the bougie through the whole length of the urethra, so that the end of it shall be in the bladder or only to pass it through the stricture a little way, so that its end shall remain in the urethra. jNothing but experience can determine this question ; and, perhaps, in such cases we seldom make a fair trial, generally pushing the bougie on to the. bladder; though if we observe the consequences of bougies not passing in those cases where they either cannot pass far beyond the stricture or not at all, we find no inconvenience arising from this circumstance, except when they are applied with two much force, so as to make a new7 passage. The common idea is that it will be more hurtful to allow the end of the bougie to lie in the urethra than in the bladder; but this seems to be more founded in theory than practice. Some people have such a quantity of calculous matter in their urine, or so great a disposition in their urine to deposit its calculous matter, that it only requires the presence of an extraneous body in the bladder to become an immediate cause of stone; for I have observed in some that the end of a bougie cannot remain in the bladder a few hours without being covered with a crust of calculous matter. Such people I have generally advised to use as much exercise as all other circumstances will allow. Bougies, when first introduced, often produce sickness, and sometimes even fainting. I have seen a patient become sick, the colour leave his face, a cold sweat come on, and at last a deliquium; but all these effects soon go off, and seldom return upon a second or third trial. They at first produce an irritation on the urethra, which gives pain in the time of making water, but goes off on repetition. They produce a secretion of pus in those cases where there was none, and generally increase the discharge where there

* Added : "A gonorrhoea or occasional gleet relieves the spasmodic state of a stricture upon the same principle as the passing a bougie a few inches down the urethra : the irritation near the glans penis takes off the spasm upon another part of the canal."—Home. CIRCUMSTANCES ATTENDING THE USE OF BOUGIES. 121

is one previous to the application of them; but this effect gradually ceases. It frequently happens that swellings in the lymphatic glands of the groin arise from the use of bougies, but I never saw them advance to suppuration. As in most of such cases there is a discharge of matter previous to the bougie being passed, they can hardly be owing to the absorption of matter, but must arise from sympathy. When treating of the stricture I observed that it was often the cause of a swelling in one or both testicles; and further, that the passing of a bougie often removed that complaint. I may now observe that a very common consequence of the passing a bougie is a swelling of the testicle. This also arises from sympathy, and, like the swelling of the glands, is a common effect of all irritations of the urethra.* It may not be improper here to add some observations on the figure and composition of bougies. They ought to be about two inches longer than the distance between the glans and the stricture, or more if they can pass freely, so as always to allow an inch to bend upon the glans, and another to pass beyond the stricture. The thickness should be according to the size of the stricture; at first such as will pass with a small degree of tightness, and this should be gradually increased as the contracted part enlarges. But when the urethra has become of the natural size the bougie need not be further increased, but its use still continued, as has been observed. With regard to the shape, they should not taper from end to end when very small, but should be nearly of an equal thickness till within an inch of their smallest end, after which they should taper to a point, forming a round wedge fitted to pass into the stricture ; and this form gives them greater strength than when made to taper from one end to the other. The consistence ought to vary according to the nature of the case and size of the bougie. If the stricture be near the glans, a stiff bougie may be used, and the whole may be made to taper gradually, because a short bougie will always have sufficient strength for any pressure that is necessary; but if the stricture be more deeply seated, as about the bulb, where the passage begins to take a curve, the bougie must be a little thicker in its body to support the necessary pressure. If the stricture be anywhere in the bend of the urethra, or near the bladder, the bougie should be very flexible (although this is contrary to our general position), because in this case it must bend in order to adapt itself to the curve of the passage, which it ought to do with ease: for when it bends with difficulty it does not make its pressure upon the stricture, but upon the back

* Added : " A gentleman who has had a stricture for many years, which at times is attended with a great deal of spasm, but has never any irritation in the testicles, upon my passing a bougie smeared with a stimulating oil for a few minutes to remove the spasm, an irritation and swelling of the left testicle came on. He afterwards caught a gonorrhoea, which entirely removed the spasm while it lasted, but also brought on a swelling of the testicle."—Home. 122 HUNTER ON THE VENEREAL DISEASE. part of the urethra, and therefore does not enter so easily, which circumstance makes it more difficult to enter a stricture near the bladder than near the glans. In the composition of the bougie the consistence is the most material thing to be considered, the medical properties, as far as known, being of little consequence. The materials of which they are commonly made are wax, oil, and litharge. The litharge gives them smoothness, and takes off the adhesive quality which they would have if made of wax and oil only. A composition which answers well is three pints of oil of olives, one pound of bees-wax, and a pound and-a-half of red lead, boiled together upon a slow fire for six hours.

§ 1. Of a new Passage formed by Bougies.

The greatest evil arising from the improper use of the bougie, and the most dangerous, is where it makes a new passage.* I mentioned before that this generally rose from an attempt to produce ulceration by the application of the end of the bougie to the stricture in cases where a bougie could not pass ; for in those cases where a bougie passes there can be no danger of such an effect. This new passage is seldom carried so far as to produce either an increase of the present disease or a new one, although sometimes this happens; yet it prevents the cure of the original disease, for it renders both the application of the bougie and caustic to the stricture so uncertain that a continuance of either is dangerous, as it may increase the mischief and at last produce very bad consequences. This new passage is generally along the side of the old one when in that part of the urethra which is on this side of the bend, and it is made in the spongy substance of the urethra ; but when it is made at the beginning of the bend, it passes on in a straight line through the body of the urethra, about the beginning of the membranous part, and goes through the cellular substance of the perinseum towards the rectum. When the new passage is made between the glans and the bend of the urethra, it may take place on either side of the canal equally, in the spongy substance of the urethra ; between the canal and the skin of the penis or scrotum; and it may be between the canal and the body of the penis. The situation of it will make some difference in the operation necessary for the cure of this complaint. When a new passage is made I know of no other method of cure than to open the part externally: and the opening must be made in that part of the urethra which is most convenient for coming at the stricture, regard being had to the other external parts, such as the scrotum. If the stricture be before the scrotum the new passage will be there also, and therefore the operation must be made of course before that part; but if the stricture is opposite to the scro- ♦Vide Plate II. fig. 1. CIRCUMSTANCES ATTENDING THE USE OF BOUGIES. 123

turn, the bottom of the new passage may also be opposite to this part; but if the new passage is of a considerable length, its bottom or termination may be in the beginning of the perinasurn ; and in either situation the operation must be begun behind the scrotum, or indeed may be made a little way into it. But if the stricture and new passage are in the perinasurn, then the operation is to be performed there. The method of performing this operation is as follows. Pass a staff, or any such instrument, into the urethra as far as it will go, which will probably be to the bottom of the new passage, and that we may be certain is beyond the stricture. Feel for the end of the instrument externally, and cut upon it, making the wound about an inch long if the disease be before the scrotum, and an inch and a half, or more, if in the perinseum. If the new passage be between the urethra and the body of the penis, then you will most probably get into the sound urethra before you come to the instrument or new passage; if so, it is not necessary to go further in order to get into the bladder, as we may be certain that this part of the urethra is behind the stricture. Having proceeded so far, take a probe, or some such instrument, and introduce it into the urethra, by the wound, and pass it towards the glans, which will be passing it forwards towards the stricture. If it meet with an obstruction there, we may be certain it is the stricture, which is now to be got through, and which will afterwards be easily enlarged. To complete the operation, withdraw the probe, and introduce in the room of it a hollow canula forwards to the stricture ; then take another canula and introduce it from the glans downwards till the two canulas oppose each other, having the stricture between them, an assistant laying hold of the urethra on the outside, between the finger and thumb, just where the two canulas meet, to keep them in their places; then through the upper canula introduce a piercer, which will go through the stricture, and pass into the lower canula ; this done, withdraw the piercer, and introduce a bougie into the same canula in the same way, being careful that it passes into the lower canula; then withdraw the lower canula, and the end of the bougie will appear in the wound; lay hold of the bougie there, and withdraw the upper canula over the bougie, leaving the bougie in the urethra : now the lower end of the bougie is to be directed into the urethra leading on to the bladder, and pushed on to that viscus. It may be further necessary to lay the whole of the new passage open, that it may all heal up; for it is possible that this new passage may often receive the bougie, to be applied in future, which would be troublesome, and might prove an obstruction to the cure. If the new passage be betw-een the skin and the canal of the urethra, after cutting down to the instrument, you must go further on in search of the natural canal, and, when you have found it, introduce a probe into it towards the glans, to find the stricture; and when this is done go on with the operation as above described. 124 HUNTER ON THE VENEREAL DISEASE.

The bougie must be left in the passage, and as it may be found difficult afterwards to introduce another readily into the bladder, the longer the first is allowed to remain so much the more readily will the second pass. I am not certain but that it would be better to push on the hollow canula at first, and keep it there for some days, at least till the inflammation is over, and the parts have adapted themselves to that body, which will make a bougie pass more easily afterwards. The bougies must be gradually increased in size, and continued till the wound is healed up. The first case of a new passage formed by a bougie which I ever sawT was at the hospital of the third regiment of guards, about the year 1765. A young soldier had a stricture, for the cure of which he had bougies regularly passed for near half a year without any relief. The bougie had gone further than at first by two inches, and therefore seemed to have gained ground on the stricture. This seemed to justify the continuance of the practice; but it being suspected that there was something more than was then understood, I was consulted, and without foreseeing what was really the case, I proposed that an opening should be made into the urethra where the obstruction was, and carried further back if necessary, in search of the sound urethra. This was accordingly done in the following manner: the graved staff was first passed as far down as it could go, which was to the bottom of the new passage ; the scrotum was pulled up upon the penis, when the end of the staff was prominent towards the skin a little way above the perinasurn, and there an incision was made on the end of the staff about half an inch long; this disengaged the end of the staff, which was pushed out at the wound; then search was made for the other orifice which led to the bladder, on a supposition that that orifice was the stricture; but none being to be found, we tried to trace it by blowing with a blowpipe into the bottom and lower part of the wound; but no orifice could be observed. We then began to suspect that we were not in the urethra. To determine if we had been in the urethra, I began to dissect with care the parts at the bottom of the wound, and laid bare the musculi acceleratores. I then made an incision into the body of the urethra and came to the true canal, which was easily discovered. When this was done we passed a probe on to the bladder, then withdrew, turned, and passed it from this wound towards the glans penis, but found that it went not much more than two inches that way, and then stopped. This struck us with a new idea of the case, for we were now sure that the end of the staff had not been in the urethra, but in a new passage made in the spongy part of the urethra, for two inches beyond the stricture. We now°passed a staff from the glans down the urethra, and another up from the last wound to see at what distance the ends of the two instruments were which would give us the length of the stricture. We found. by taking hold of the urethra between the finger and thumb on the outside, that the two ends were close together. What was to be done next was our consideration; it immediately struck us that we CIRCUMSTANCES ATTENDING THE USE OF BOUGIES. 125

might force our way through the stricture with safety. The gentleman who assisted me in the operation passed a blowpipe one fifth of an inch in diameter (being not sufficiently furnished with instruments,) from the wound forwards to the stricture; and then I took a silver canula, open at both ends, which had an iron piercer longer than itself, and passed it dowm to the stricture from the glans ; and now the end of the canula opposed the end of the blowpipe, and they wrere almost close upon one another. They were kept in this position, with the finger and thumb applied on the outside of the penis, like splints on a broken bone. 1 then introduced the piercer and pushed it on, which went through the stricture into the hollow of the blowpipe. Great care was taken not to push too forcibly, lest the two ends of the hollow tubes should slip by one another, which they would do if not held firmly, as actually happened twice in this case; but we succeeded the third time. I then pushed on the canula through the stricture, and with it pushed out the blowpipe. The next object was to pass a hollow bougie along the urethra to the bladder, to do which the small end of it was introduced into the canula, which being pushed on forced out the canula at the wound; we then passed a director into the Other orifice of the urethra, leading on to the bladder, and put the end of the bougie into the groove of the director, and pushed it along the groove to the bladder; and before we withdrew the director we turned it round with its back to the bougie, that the end of the bougie might not stop against the end of the groove, and so be pulled out again. After all this was done one stitch was made in the urethra, but the external wound in the skin was left for the passage of the urine, that it might not insinuate itself into the cellular membrane. We dressed the wound superficially, and applied the T bandage, which was slit to go on each side of the scrotum, and just where it came to the scrotum we tied the two ends together, which supported the scrotum and kept it forwards on the penis; and the two ends that came from this knot on each side of the scrotum wore tied to the circular part that came round the body. The patient had some slight fever for a day or two, and the urine came partly through the bougie and partly by the side of it, through the wound. A swelling of one testicle came on ; likewise a swelling of the glands of the groin, pain in the belly, sickness, and at times vomiting, all which symptoms were owing to sympathy, and entirely went off in five or six days. The water, in nearly the same time, came entirely by the natural passage. The bougie was changed from time to time till the cure was completed. 12 126 HUNTER ON THE VENEREAL DISEASE. CHAPTER VI.

OF DISEASES IN CONSEQUENCE OF A PERMANENT STRICTURE IN THE URETHRA.

Strictures in the urethra produce almost constantly diseases in the parts beyond them; that is, in the part of the urethra between the stricture and the bladder. They bring on in most cases a gleet, as has been described, and often a considerable distension of the part of the canal beyond the stricture; also inflammation and ulceration, and in consequence of them diseases in the surrounding parts, as in Cowper's glands, the prostate, and the surrounding cellular membrane, forming abscesses there, and at last ulceration, for the purpose of making a new passage for the urine. The bladder is also often affected, and sometimes the ureters, with the pelvis of the kidneys, and in some cases the kidneys themselves. All these are effects of every permanent obstruction to the urine; some of them are methods which Nature takes to relieve the parts from the immediate complaints; such are the increase of the urethra beyond the stricture, and the enlargement of the ureters and pelvis of the kidneys, which are only to be considered as the parts accommodating themselves to the immediate consequence of the obstruction, which is the accumulation of urine. Of these complaints I shall take notice in their order.

§ 1. Of the Enlargement of the Urethra.

The urethra beyond the stricture I have observed is enlarged, because it is more passive than the bladder, and yields to the pressure of the urine. It is naturally passive while the bladder is acting, by which means it becomes distended in proportion to the force with which the bladder acts, and the resistance of the stricture. Its internal surface often becomes more irregular and fasciculated. It is also more irritable, the distension becoming often the immediate cause of spasms in that part, and these spasms are most probably excited with a view to counteract the effort produced by the action of the bladder.

§ 2. Of the Formation of a New Passage for the Urine.

When the methods recommended above for the removal of stricture have either not been attempted or have not succeeded, Nature endeavours to relieve herself by making a new passage for the urine, which, although it often prevents immediate death, yet, if not remedied, is productive of much inconvenience and misery DISEASES CONSEQUENT ON PERMANENT STRICTURE. 127

to the patient through life. The mode by which Nature endeavours to procure relief is by ulceration on the inside of that part of the urethra which is enlarged and within the stricture. The ulceration commonly begins near or close to the stricture, although the stricture may be at a considerable distance from the bladder; therefore we must suppose that there is some circumstance besides the distension of the urethra by the urine, which determines the ulceration to a particular part. This circumstance rrmst probably arises immediately out of its vicinity to the stricture, and may be called contiguous sympathy. The stricture is often included in the ulceration, by which it is removed, the disease cured, and a stop sometimes put to the further ulceration ; but unluckily this is not always the case. We may observe that this ulceration is always on the side next to the external surface, as is common in abscesses. As this ulceration does not arise from preceding inflammation, and as it cannot be said that the urine acts exactly as an extraneous body, because it is in its natural passage, we find that there is but very little inflammation of the adhesive kind attending these ulcerations. We must allow, however, that the urine produces the ulcerative disposition here, like matter on the inside of an abscess, although not so readily. Whenever, therefore, the internal membrane and substance of the urethra are removed by absorption, the water readily gets into the loose cellular membrane of the scrotum and penis, and diffuses itself all over those parts, not having been previously united by the adhesive inflammation; and as the urine has considerable irritating powers when applied to the common cellular membrane, the parts inflame and swell. The presence of the urine prevents the adhesive inflammation from taking place; it becomes the cause of suppuration wherever it is diffused; and the irritation is often so great, more especially in cases where the urine has been allowed to become very stale, that it produces mortification, first in all the cellular membrane, and afterwards in several parts of the skin, all of which, if the patient live, slough away, making a free communication between the urethra and external surface, and produce fistulas in perinseo. We may observe, however, that the want of the adhesive inflammation in these ulcerations appears to be peculiar to that part of the urethra which lies between the membranous part and the glans penis; for we find from experience that when this process takes place further back, as in the prostate gland, a circumscribed abscess is generally formed. This may arise from the difference in texture of the cellular membrane of the parts, the first admitting of the diffusion of the urine very readily from the looseness of its texture, the other producing adhesions before the urine is allowed to pass, which adhesions afterwards exclude it. It sometimes happens that the urine gets into the spongy substance of the body of the urethra, and is immediately diffused through the 123 HUNTER ON THE VENEREAL DISEASE. whole, even to the glans penis, producing mortification of all those parts, as I have more than once seen. When the urine has made its way into the cellular membrane, although the ulceration of the urethra is in the perinasurn, yet it generally passes easily forwards into the scrotum, that part being composed of the loosest cellular membrane in the body. When the seat of the ulceration is in the membranous or bulbous part of the urethra, and the pus ancHirine have found their way to the scrotum, there is always a hardness extended along the perinasurn to the swelled scrotum, which is in the tract of the pus. Ulceration cannot be prevented but by destroying the stricture; but when the water is in the cellular membrane, which is the state we have been describing, the removal of the stricture will in general be too late to prevent all the mischief, although it will be necessary for the complete cure; therefore an attempt should be made to pass a bougie, for perhaps the stricture may be included in the ulceration (as was mentioned before), and thereby allow a bougie to pass. When this is the case, bougies must be almost constantly used to procure as free a passage forwards in the right way as possible. When the bougie will not pass, I am afraid that the caustic, as described in the case of a stricture, would in many cases be too slow in its operation, and in others it cannot be tried, as the situation of the stricture is often such as will not admit of it. While we are attempting the cure of the stricture every method is to be used that removes inflammation, particularly bleeding. Great, relief may be obtained by exposing the parts to the steam of hot water; but this is merely a palliative cure. The warm bath, ojDium, and the turpentines, given by the mouth, and also by the anus, will assist in taking off" any spasmodic affection; but all "these are too often insufficient, and therefore immediate relief must be attempted, both to unload the bladder, and prevent any further effusion of urine into the cellular membrane. This must be done by an operation, which consists in making an opening into the urethra somewhere beyond the stricture, and the nearer to the stricture the better. The method of performing the operation is first to pass a director or some such instrument into the urethra, as far as the stricture; then to make the end of the instrument as prominent externally as possible, so as to be felt, which in such a case is often difficult, and sometimes impossible. If it can be felt, it must be cut upon, and the incision carried on a little further towards the bladder or anus, so as to open the urethra "beyond the stricture ; this will be sufficient to allow the urine to escape, and to destroy the stricture. If the instrument cannot be felt at first by the finger, we must cut down towards it, which will bring it within the feel of the finger, and afterwards proceed as above directed If the stricture in the urethra be opposite to the scrotum, it being impossible to make the opening there, it must be made in the per* nasum, in which case there can be no direction given by an instru- DISEASES CONSEQUENT ON PERMANENT STRICTURE. 129

ment, as one cannot be made to pass so far; therefore we must be guided by our knowledge of the parts. The opening being made, the stricture is to be searched for as described in the operation, in cases where a false passage has been made, by passing a probe from the wound forwards, towards the glans. The other steps of the operation will be nearly the same. In whichsoever way the operation is performed a bougie must be introduced, and the wound healed up over it. In my opinion a catheter answers this purpose better. Great attention should be still paid to the inflammation, which arises in consequence of the urine having been diffused in the cellular membrane, as before described. Where the inflammation is attended with suppuration and mortification, it will be necessary, as well in this ease as in that where no operation is required, to scarify the parts freely, to give an opening both to the urine and pus. Where mortification has taken place in the skin, the scarifications should be made in the mortified parts, if it can be done with equal advantage, and this with a view to prevent irritation. In total suppressions of urine, from whatever cause, the urine should never be allowed to accumulate, and should either be drawn off frequently, or a catheter should be kept continually in the urethra and bladder, because we should on no account allow the bladder to be distended beyond an easy state; for if it be, it always brings on debilitating and alarming symptoms, as paralysis of that viscus. In many suppressions of urine, as in cases of strictures, it is impossible to draw off the water. In some cases where the urethra is ulcerated, and the urine gets into the cellular membrane of the penis and prepuce, so as to distend them much, producing a phimosis, it becomes impossible to find the orifice of the urethra, The following case illustrates most of the preceding doctrines, A gentleman of a scrofulous habit had often had venereal gonorrhoeas, which, being severe, commonly produced swellings, or knobs, along the urethra, upon which account he was advised to avoid this disease as much as possible. When in the country, in November, 1782, he was attacked with a slight cold or fever, and a small discharge from the urethra, which, he could not determine to be venereal. In this state he set out for London, but was seized on the road with a suppression of urine, which detained him two days at an inn. On his arrival in London I found him feverish. He spoke to me only of a discharge from the urethra ; but as I did not conceive that the fever could arise from that cause, I desired him to be easy on that account. He was taken with a shivering fit, which made us suspect it might terminate in an intermittent, and we waited for the result. He still complained of the discharge, and mentioned a soreness in the perinasurn, both when he made water and when he pressed it externally. On examining the perinasurn, I found a fulness there, from which I suspected a stricture, and inquired particularly how he made water in common; he declared very well, which led me from the true cause. This swelling was 130 HUNTER ON THE VENEREAL DISEASE. regarded as the effect of an inflammation, either in consequence of the fever, the disposition of the part, or both, increased by sitting in a postohaise for several days. The part was fomented and poulticed, and leeches were applied several times. He had another shivering fit three days after the first, which, if his disease had been an intermittent, would have constituted a quartan ; but he had another some hours after, which made us give up our suspicions of an intermittent. We now began to suspect that matter was forming in this part, although I could not feel anything like a fluctuation; nor was the pain of the throbbing kind, or so acute as we commonly find it in the suppurative inflammation. What in some degree surprised me was, that the swelling came forwards along the body of the penis towards the os pubis, while it seemed to be diminishing in the perinasurn. He now began to find a difficulty in making water, with a frequent desire, which increased till there was a total suppression. I pressed on the lower part of the belly to determine whether or not the urine was secreted and accumulated in the bladder; but I could not find any fulness; nor did he then feel pain on pressure; however, about twenty-four hours after he began to complain of a great desire to make water, and a pain in the lower part of his belly ; and the ha::d being placed there, a fulness of the bladder was readily felt. It was now clear that the water ought to be drawn off; but as I still suspected mischief in the urethra as a cause in his complaint, I took the necessary precautions. I provided myself with catheters and bougies of different sizes; and to be as much upon my guard as possible, I introduced a bougie of a small size first, and found a full stop about the bulbous part of the urethra ; I then took a smaller, which passed, but with difficulty. I afterwards passed a small catheter on to the stricture, where it stopped ; but as it was absolutely necessary that the water should be drawn off, I used more force than I otherwise should have done : it went on, but with difficulty, and I was not certain whether it was in the natural passage or was making a new one. When the bougie had gone so far as certainly (if in the right passage,) to have entered the bladder, I found that no water came; I therefore pressed the lower part of the belly, and the water immediately came out through the catheter, whence it appeared that the bladder had lost its power of contraction. The water was drawn off three times everv day, that is, every eight hours, to give as much ease to the bladder as possible; but still it was necessary to press the bellv, to assist the discharge of the urine ; and it was upwards of a fortnight before the bladder began to recover its power of contracting. The swelling in the perinasurn still continued, advancing along the body of the penis, and spreading a little on the pubes; it seemed to extend along the projecting part of the penis, and at last filled the whole cellular membrane of the prepuce, but did not in the least affect the scrotum. This swelling appeared to be owing to the urine having found its way into the cellular membrane of the perinasurn, and f?om thence pro- DISEASES CONSEQUENT ON PERMANENT STRICTURE. 131

ceeding along the side of the- penis. When the prepuce became much loaded with water, a very considerable phimosis took place, which made the introduction of the catheter into the orifice of the urethra very uncertain; so much did the swelled prepuce project over the glans. I was obliged to squeeze the water back into the body of the penis, and introduce a finger, and feel for the glans, and on this finger introduce the catheter; and in a few minutes I generally found the orifice. The nature of the case was now plain; for ulceration had taken place beyond the stricture, and the swelling had arisen from the urine having insinuated itself into the cellular membrane of the perinasurn ; and as the urine escaped from the urethra, it was pushed forwards where the cellular membrane was loosest, till it got to the very end of the prepuce as before mentioned. By this time he was become extremely low and irritable; his pulse quick and small; his tongue brown, dry, and contracted ; his appetite gone, with great drought, bad sleep, and the first stages of a delirium coming on. This discovery of the true state of the case gave a change to the mode of treatment. Instead of evacuation to lessen inflammation, the bark and cordials were given, with as much food as his stomach would bear. Their effects on the constitution were almost immediate, and he began to recover, although but slowly. I made two punctures in the phimosis at the extremity, with a view both to take off'the tension and to evacuate the urine from the cellular membrane, between the penis and the skin. Blisters began to form on the skin of the penis, and at last mortification took place in several parts, especially on the prepuce, which I divided at the mortified parts, and thereby the glans became exposed, so that the catheter could now be introduced easily. Upon squeezing the swelling, from the perinasurn forwards along the penis, I could force out at the mortified parts, air, water, and some matter. The cellular membrane under the skin was almost wholly mortified. When bounds were set to the mortification, the sloughing cellular membrane began to separate ; and a good deal was cut away to keep the parts clean, and to allow of a freer vent for the matter. Now that separation was taking place, it was clear that no more water from the bladder could insinuate itself any further into the surrounding cellular membrane ; therefore it was not necessary to pass the catheter any more, and the patient was allowed to make water whenever he had a call, which when he did, the water came both ways, through the urethra and through the cellular membrane, at the openings where the skin had sloughed oft'. As the sloughs separated they came forwards from behind, at the side of the scrotum, so that I could draw them out; and when most of the mortified cellular membrane was removed, I saw a part, about the size of a sixpence, of the tendinous covering of the corpus cavernosum dead, which was also allowed to slough oft". Most of the water now came through the sore. The parts became more painful; he was more restless, and one morning he had a shivering fit. I endeavoured to pass a bougie down the sore, be- 132 HUNTER ON THE VENEREAL DISEASE. tween the skin and penis, but could not: in the evening of the same day a gush of matter and blood came out of the sore, which immediately relieved him, and he began to mend again, and continued to do so, both in the parts and his general health, the water coming both ways, but often varying in quantity between the two passages ; more and more, however, came the right way, till at last the new passage closed up entirely. While the external parts were healing I passed a bougie occasionally, to keep the passage clear and open. To find out the situation of the internal opening, I ordered the patient to press on different parts of the perinasurn while he was making water, by which means he found that by pressing upon a particular spot he could stop the water from flowing through the new passage. He was directed, however, not to press too hard, for fear of forcing together the sides of the natural passage. Upon erections, the penis was bent to the side that had suffered; but in time the parts gradually recovered their natural form.

§ 3. Of Inflammation in the Parts surrounding the Urethra.

Inflammation arising from distension and irritation of the urethra often extends considerably further than the surface of that canal, for the surrounding parts become the seat of inflammation, the situation of which will commonly be according to the situation of the stricture, producing the distension. Thus we find the inflammation affecting the prostate glands, the membranous part of the urethra, the bulb, and probably Cowper's glands, with other parts of the urethra between the bulb and the glans. But inflammation in the surrounding parts of the urethra is not always a consequence of distension or stricture: it arises often from other irritations in this canal, such as violent gonorrhoeas and very irritating injections. When inflammation attacks these parts it is of the true adhesive kind, and therefore when suppuration takes place an abscess must be formed, unless the inflammation be resolved. The matter, according to a general principle in abscesses, points externally; when the seat of the abscess is either in the prostate gland, membranous part, or in the bulb, the matter will point in the perinasurn ; or the abscess may be formed fowards in the scrotum, or before it, according to the situation of the stricture. The scat of these abscesses is generally so near the inner surface of the urethra that the partition between them often gives way, and they open internally, as frequently happens in an abscess by the side of the rectum, so that the matter is at once discharged by the urethra, or carried back into the bladder to be discharged with the urine. When the internal opening only takes place, I believe it is owing to the ulceration on the inner surface of the urethra, as has been already described; and in these cases also the stricture is thTwX'wTfi^ mr thG absC6SS and ulce™tion, by which means the water will find a free passage forwards ; but the urine has also a free passage into the abscess, which we may suppose retards its healing, and often becomes the cause of its opening externally • but DISEASES CONSEQUENT ON PERMANENT STRICTURE. ]33

here, from the adhesive inflammation having taken place, the urine cannot insinuate itself into the surrounding cellular membrane, so as to produce the consequences mentioned in treating of the way in which Nature endeavours to relieve herself. In such cases we find that upon pressing the abscess externally the matter is squeezed into the urethra, and so out by the glans. It sometimes happens that a catheter can be introduced into the opening of such an abscess, by which means it can be washed by injecting something through the catheter, whereby probably it may be sooner healed. It more frequently happens that such abscesses open both internally and externally, discharging themselves both ways. These ulcerations and suppurations, of both kinds, are to be considered as efforts of Nature, or, to speak more physiologically, as a natural consequence arising from such irritation, by which, as the urine cannot pass by the old passage, a new one is made to prevent further mischief. Both these diseases, when they open externally, if not properly treated, often lay the foundation for the complaint commonly called the fistula in perinaso, which is owing to the bottom of the abscess having a less disposition to heal than the external parts. It may be further supposed, that the urine passing into the abscess by the inner orifice, and making its escape into the external, keeps up a constant irritation in the sore, which in some measure may prevent an union of the sides, and rather dispose them to form themselves into a hard callous substance, the inner surface of which loses the disposition to union, and assumes the nature of an outlet. But it is more than probable, that the cause which prevents these abscesses from healing depends upon their first action often continuing in full force; that is, a diseased state of the internal parts, as will be further illustrated when we shall treat on the fistula in perinaeo. They often heal up at the orifice in the skin, especially if the water has a free passage forwards ; but if the internal opening is not perfectly consolidated, some water will insinuate itself into the old sore, become the cause of fresh inflammations and suppurations in the surrounding parts, which frequently open externally in different places, not following the old canal, although they sometimes communicate with it and form branches, as it were, from the principal trunk. I have seen the scrotum, perinasurn, and inside of the thigh, full of openings, which were the mouths of so many sinuses leading to the first-formed abscess. When the abscess opens only externally, which is seldom the case, it is to be considered as a common abscess. When these inflammations arise from stricture, the difficulty in making water is increased in the time of the inflammation, which is generally so great as to compress the sides of the urethra together for some way; besides, the stricture itself will become tighter from being inflamed. Inflammation in these parts, even when it does not arise from a stricture, brings on a suppression of urine ; but in such cases a bougie or catheter can be passed, the latter of which, 134 HUNTER ON THE VENEREAL DISEASE.

in cases of obstruction arising from contiguous swellings, as tumours, inflammations, and swelled prostate gland, is the proper instrument, as the sides of the urethra would be pressed together immediately upon withdrawing the bougie, by which the urine would be as much as ever prevented from following.

^ 4. 0/ the Treatment of the Inflammation in the surrounding Parts.

The inflammation of these parts is to be treated like other inflammations. Resolution is much to be wished for; but it is almost impossible it should take place where stricture is the cause. When the stricture is removed, either by ulceration or a bougie, we have only the inflammation to contend with; but this seldom happens, for the inflammation is but too often accompanied with suppuration. When suppuration takes place, the sooner the abscess is opened externally the better, as that may in some cases be the means, though seldom, of preventing its opening internally; yet it may prevent the inner opening from becoming so large as it otherwise might be. The opening externally should be large; and if the stricture is not involved in the suppuration, then it must be destroyed, because there can be no cure while the water passes through the new opening. I have succeeded with the caustic even in strictures of long standing. When the stricture will admit of the passage of a bougie through it, it is to be kept almost constantly in the urethra, and to be withdrawn only at the time of making water: this will allow the urine to pass more freely through the urethra, without escaping through the sore. The sore must be healed from the bottom.* Hollow bougies are recommended in such cases, after the stricture is destroyed, to prevent the urine passing through the wound. This instrument admits of a constant dribbling of urine through it; but the bougie may be occasionally stopped up, and the urine permitted to pass when there is a desire to make water. It becomes under certain circumstances the worst instrument possible; for if its canal is not of a size sufficient to let the water pass as freely as the contraction of the bladder requires, the water will pass easily by the side of the bougie to the abscess, and, not getting forwards beyond the stricture, flow out at the abscess : to avoid this effect as much as possible, the hollow bougies should be as large as the strictured part will allow, and its sides should be as thin as possible, that its passage may be the larger. The elastic gum has these two properties in a higher degree than the spiral wire covered with waxed

* Added : "In many such cases of abscess in perinaeo, where the stricture has been destroyed, the passage at that part is so irregular that the catheter is the best instrument to use; and where the parts are much contracted, a flexible catheter may be readily introduced down to the stricture, and then a curved stilet passed into it, which will admit of its being directed into the bladder. In this way I have sometimes succeeded when all other attempts have failed."—Home. DISEASES CONSEQUENT ON PERMANENT STRICTURE. 135

cloth. But, as I doubt very much that the passage of the urine may be a hindrance to the healing of the sore, I am the less solicitous about such practice; for we find that after lithotomy the parts heal very readily ; and even in this operation the external parts which are not diseased heal up very readily. I suspect that the want of disposition to heal arises from the strictures not being sufficiently subdued, or the deeper parts not being in a healthy state. When these suppurations are left to themselves, and no method tried to remove the stricture, and of course nothing introduced into the urethra, the stricture sometimes closes entirely, so that no water can pass forwards through the urethra ; and, therefore, before any attempt can be made to heal the fistulous orifices, a passage must be made through the united parts. This cannot be done with a bougie; and if this union of the parts is before the bend of the urethra, which most commonly it is, nothing but the caustic can be applied with any prospect of success, as we shall mention more fully in treating of the fistula in perinaso.

§ 5. Of the Effects of Inflammation in the surrounding Parts upon the Constitution.

The effects which these attempts to form a new passage for the urine have upon the constitution are very considerable; much more so than what one would at first expect. Those cases appear to be most formidable which begin bv ulceration on the inner surface of the urethra, and where the water diffuses itself into the cellular membrane of the scrotum and penis. Those where the inflammation is circumscribed are more of the true abscess, and therefore do much less mischief to the parts than when the urine is diffused in the cellular membrane. In these last, if not soon relieved, the patient sinks, and a mortification comes on. If, before the patient sinks, a separation of the slough takes place, this separation performs the operation of opening, and the patient may recover. We should not, I believe, wait for such separation of the mortified part, but make an opening early, upon the first knowledge of a diffusion of water into the cellular membrane; and we should be guided as to situation by introducing a staff into the urethra on to the stricture. But in some cases this cannot be done; for when the urine gets into the corpus spongiosum it produces mortification of all these parts, and renders the whole so indistinct that often no urethra can be found. The effects that the circumscribed inflammation has upon the constitution is generally not so serious as the above; for mortification as seldom takes place in this as in abscesses in general. When the abscess is from the bulb backwards, there is generally a sharp sympathetic fever, because the abscess will be of considerable size before it gets to the skin of the perinasurn, and is generally attended with great pain ; but this pain goes off by the formation of the matter, especially if opened early. 136 HUNTER ON THE VENEREAL DISEASE.

As there is a great disposition to violent action, attended with great weakness, in such cases, more especially in those of the first kind, it is advisable to give the bark early, and in considerable quantity ; but I apprehend it is necessary to give along with it sudorifics, as some of the preparations of antimony, there being generally a good deal of fever. The bark gives strength, and also in some degree lessens irritability; but it should be assisted by other medicines.

It often happens that the new passages for the urine do not heal on account of the strictures not being removed; and even when the stricture is removed they frequently have no disposition to heal. In both cases they become fistulous, and produce fresh inflammations and suppurations, which do not always open into the old sore, but make new openings externally. These sometimes arise from the first external openings not being sufficiently large, so that they heal up long before the bottom, or long before the diseased urethra and even when the external opening has been made as large as possible, it will often heal sooner than the bottom, and become fistulous at last. It is very common for these diseases to affect the constitution so as to bring on complaints of an intermittent kind. I have seen several affected with regular agues, where the bark has produced no effect; but whenever the obstruction has been got the better of, or the fistulous orifice opened and in a state of healing, these complaints have entirely gone off. To cure this disease it is necessary first to make the natural passage as free as possible, that no obstruction may arise from that quarter; and sometimes this alone is sufficient; for the urine, finding a free passage forwards, is not forced into the orifice, and the fistulas heal up. The bougie may bring on an inflammation on the urethra at this part, and produce adhesions there; but if this effect is not produced early, the bougie will rather do harm if applied too often, and too long at a time, as will be more fully explained. But the dilatation of the stricture is not always sufficient; it is often necessary to perform an operation on the fistulas, when they alone become the obstacle to the cure, which I shall now describe.

§ 7. Of the Operation for Fistulce in Perinaeo.

When the before-mentioned treatment is not sufficient for the cure of the new passages, a method should be followed similar to that used in the cure of fistulas in other parts, by laying them freely open to the bottom, and even making the orifice in the urethra a fresh sore if possible. This will be difficult in many situations of the internal orifice; and the mode of opening, and other circumstances attending the operation, will vary according to the situation. DISEASES CONSEQUENT ON PERMANENT STRICTURE. 137

That as little of the sound part of the inner surface of the urethra may be opened as possible, and that the diseased part may be fully exposed, it is necessary to be well directed to the inner orifice, far which we have commonly two guides: one is a staff introduced into the urethra as far as is thought necessary, or as far as it will go (which will only be to the stricture, where the stricture still exists, or it may pass on to the bladder in cases where the stricture has been destroyed); the other guide is a probe passed into the fistulous orifice. The probe should be first bent, that it may more readily follow the turns of the fistula, and be introduced as far as possible; if it could be made to meet the staff so much the better, as then the operator could cut just what is necessary. If the fistula is tolerably straight, so as to admit the passing a director, it is the best instrument for operating upon. If neither the probe nor the director can be made to pass on to the staff, we must open as far as they go, and begin searching anew after the remainder of the passage with the same instrument, and pursue it till the whole fistulous canal is laid open. If there are any sinuses, they are to be laid open if possible; but it frequently happens that they cannot be followed by the knife, some running along the penis, where the scrotum is attached, others passing on towards the pubes, round the penis, while others are about the membranous part of the urethra. In such cases some degree of violence may be used, and I have several times introduced my finger into these sinuses, and have torn the parts so as to produce a considerable inflammation, by which means they often suppurate, granulate, and unite. If the situation of the internal orifice is opposite to the scrotum it will be difficult to get to it; but I imagine we may use great freedom with the external parts, whatever they are, for they are generally in a state of callosity. However, this requires judgment. In cases where the disease is before the membranous part and the stricture is not removed, a staff cannot be made to pass on to the inner orifice. In such the fistulous opening must be followed by the introduction of a probe or director into it, and by dilatation upon the instrument till the urethra beyond the stricture is found ; and then a probe must be passed on towards the glans, to meet the end of the staff at the stricture, similar to what is done in the operation where a false passage has been made by the mismanagement of the bougie. The stricture must then be destroyed, and a bougie passed, as was recommended in that operation. If either the ulceration or the abscess is formed in or near the prostate gland, then probably the stricture is near that part. In that case a staff must be passed as far as possible, and a probe or director introduced into the external orifice, and the operation is to be directed accordingly. The difference of the operation in this case from the former will be that we shall most probably be obliged to cut into the urethra on both sides of the stricture, therefore more of the canal must be exposed. As this operation is the opening of all the fistulous canals, and 13 138 HUNTER ON THE VENEREAL DISEASE.

also the destruction of the stricture, if there has been one, an instrument can afterwards, in every case, be passed into the bladder. It will most probably always be proper to introduce an instrument into the bladder, and keep it there almost constantly, so as to preserve the passage of the urethra in a regular form, while the openings made are healing ; and probably the catheter will be by much the best instrument, because it is not necessary to be withdrawn whenever the necessity to make water comes on, which a bougie must; and its introduction again is often not practicable, for its end will be apt to get into the wounds. In such cases as require a hollow canula to be left in the bladder for the purpose of drawing oft' the water, whether a catheter or hollow bougie, it is absolutely necessary it should be fixed there, or else it will in common come out by the actions of the part. To effect this it is necessary to fix that end of the instrument out of the penis to some part of the body that is the least moveable. What will answer extremely well is the common belt-part of the bag-truss, with only two thigh-straps fixed behind and made to tie or buckle before; and two or three very small rings or short tapes fixed to those straps where they pass between the thigh and scrotum ; they should not be at a great distance from one another where they are fixed behind to the belt, for otherwise they are much altered in tightness by the motion of the thigh. If they have a flat spring in them so much the better.* The common bag-truss for the scrotum answers extremely well, first by fixing two or three rings on each side of it along the side of the scrotum; and with a piece of small tape the ring of the canula can be fastened to any one of those rings that is most convenient for its situation. Whatever instrument is used for the purpose of keeping the passage clear and open while the sores are healing, whether the sores are in consequence of this operation, or in consequence of the causes of the fistulas, which I have described, there is a limited time in many cases for its continuance; for if it continued beyond a certain period, it frequently acts contrary to what was intended; at first it often assists the cure, but towards the last it may obstruct the healing of the sores by acting at the bottom of the wound as an extraneous body. Therefore, whenever the sores become stationary, I would advise the withdrawing of the instrument, and the introducing it only occasionally. The catheter will probably be still the best instrument for this purpose, as it will pass the more readily, and draw off the water at the same time: however, I have often used a bougie, and by great care have passed it with success; and probably it will be proper to use it every now and then, even when all is healed, in order to determine whether or not the passage is free from disease. The sore and the wound are to be at first dressed down to the bottom as much as possible, which will prevent the reunion of the

* Mr. Vanbutchell's springs would answer very well. DISEASES CONSEQUENT ON PERMANENT STRICTURE. 139

parts just divided, and make the granulations shoot from the bottom so as to consolidate the whole by one bond of union. When the urethra has suffered so much that abscesses have formed beyond the scrotum, the patient should ever after take great care to avoid a fresh gonorrhoea, for he seldom in that case escapes a return of the same complaints; and, indeed if he is not careful in many other respects, he is liable to returns of the same disease. If, notwithstanding this precaution, he should contract a gonorrhoea, everything heating is to be carefully avoided, particularly irritating injections. The following case shows that keeping extraneous bodies in the urethra prevents wounds made into that canal from healing. A man, aged twenty-six, came into St. George's Hospital March 2, 1783. He had laboured under a fistula in perinaso for near two years, arising from a stricture, attended with great pain and difficulty in making water. Four fistulous orifices were to be observed in the perinasurn and scrotum. The smallest bougie could not be made to pass into the bladder after repeated trials. The caustic was then applied, but without success. The operation for the fistula in perinaso was performed September 19. A catheter was first introduced as far as it would go, as a director, and all the sinuses were laid open to that catheter, which exposed near an inch in length of that instrument; then the catheter was in part withdrawn to expose that part of the urethra which was laid bare. The blood being sponged off, the orifice in the stricture was next searched for, and when found it was dilated. The catheter was now pushed on to the bladder, although with some difficulty, and the end of it was then fastened to a roller which went round the thighs; and the wound was distended with lint. He took an anodyne draught after the operation, and another at night. September 20, he had some pain in the head from the opiates ; his pulse was natural, and he had slept tolerably well. On the 21st day the catheter slipped out, and the second introduction of it gave considerable pain. The anodyne was repeated. October 1. The catheter was still to be felt by introducing a probe into the wound. From this time to the 25th nothing material happened, excepting a piece of lint of the first dressing coming away through the urethra. November 20. The wound having for some time been stationary, and showing no disposition to heal, I conceived that the catheter was now acting as an extraneous body at the bottom of the wound, and therefore desired that it might be withdrawn, and passed occasionally; and no sooner was the wound free from it but it put on a healthy look, and by the 10th of December no urine came through the wound, but passed tolerably well through the urethra ; and on the 12th the wound was quite healed, and the water came from him rather in a full stream and without pain, although we could never pass either catheter or bougie afterwards, probably from the new and old passages being irregular.*

* [It is possible that some cases may occur where the operation which is 140 HUNTER ON THE VENEREAL DISEASE. CHAPTER VII.

OF SOME OTHER AFFECTIONS OF THE URETHRA.

The substance of the urethra is muscular, and it is therefore capable of contracting its canal, similar to an intestine, so as to shut it up entirely. This makes it subject to diseases peculiar to muscle in general; which is indeed the only proof we have of its being muscular.

§ 1. Of the Spasmodic Affections of the Urethra.

In a sound state of parts these muscles are never excited to violent actions, acting simply as sphincter muscles; but when irritated they are capable of acting violently, as is best seen in some cases upon the first use of injections, the urethra often refusing the injection entirely. This seems rather to be a salutary motion to hinder things from getting into the bladder; but there are often spasmodic contractions of these muscular fibres in different parts of the canal, shutting up the passage and obstructing the course of the urine, often not allowing a drop to pass. That this also is owing to spasm upon the muscular fibres is evident, because a large bougie will sometimes pass when it is at the worst. When the contraction is near the bladder it is called a strangury, and is often produced in a sound state of parts by irritating medicines, the power of which falls upon these parts, as cantharides; and when this part is in an irritable state, the spasm may be brought on by a vast number of things, such as most of the peppers, fermented liquors of all kinds, violent exercise, &c. The urethra in cases of spasmodic stricture is more irritable than in the true stricture, which irritation indeed is in a great measure the cause of the spasm. Spasmodic strictures often bear so strong a resemblance to the cramp, that one would be apt to attribute them to the same cause as that which produces cramp. In such cases the spasm also goes off by tickling the part, similar to the removal of cramp. In all cases of very irritable urethras, where spasms very readily take place, the patient should never long retain his urine when he described by the author may be required, but such cases are undoubtedly very rare. The complete removal of the stricture is in almost all instances followed by the spontaneous closure of the sinuses in the perinseum. Until the strictured portion is dilated to the same size with the rest of the urethra, there is little improvement. As soon as that is effected, the urine is no longer diverted into the sinus, but takes the more ready course of the natural passage; and the cause which maintained the fistula being thus removed, the opening gradually contracts, and in a short time heals, without any surgical treatment whatever.] OF SOME OTHER AFFECTIONS OF THE URETHRA. 141

has an inclination to void it; for I have seen cases where this alone has brought on the spasm; and indeed these parts, when in perfect health, will be thrown into a spasmodic affection if the urine is too long confined in the bladder; while at the same time a certain fulness of the bladder, or a small degree of retention of the urine, will make the bladder contract with more force, and the urethra will for the same reason relax more freely ; therefore in cases where there is a tendency to strangury there is seldom any harm in waiting a little after the inclination comes on. I may be allowed here to caution surgeons who have not had opportunities of seeing many of these cases, when they meet with permanent strictures which are becoming troublesome, attended with frequency in making water, and a difficulty in passing it often threatening strangury, not to advise, or rather not to allow, their patients to take long journeys either on horseback or in carriages, more especially in the winter. I have known many patients labouring under such complaints taken ill in the middle of a journey, and obliged to stop for days upon the road, and who have continued in misery the remainder of the journey; and after having arrived at the place of their destination, have been laid up for months, and hove suffered from most of the before-mentioned complaints,

§ 2. Of the Cure of the Spasmodic Affection of the Urethra. It may not be improper to premise, that in diseases of the actions only of the urethra and bladder, whether spasmodic and proceeding from too great irritability, or paralytic (although two opposite diseases,) irritations on other parts have often wonderful effects, equally diminishing the action in the one and increasing it in the other. The proof of this will appear when we shall treat of the irritable and paralytic urethra and bladder: for in either part, and in either case, we find blisters applied to the lower part of the small of the back or the perinasurn, as also many other applications to this part, often produce great effects.* As spasm simply is not an alteration of structure, but is only a diseased or preternatural action arising from some irritation, it may be made to cease instantaneously. In whatever partof the urethra the spasm is, if time will allow, it is proper to try internal medicines, and also external applications, to remove it. The internal medicines that may be said to act immediately are opiates and turpentines,!

* That the parts concerned in the expulsion of the urine (as the bladder and urethra) sympathize strongly with the skin of the perinseum I believe is commonly supposed, from applications being often made to that part in cases of stoppages of urine. A gentleman who had no complaint in these parts had a small fistula at the side of the rectum, for which he often had occasion to sit over the steam of warm water and vinegar; and this application to the perinaeum never failed of making him void his urine. f Dr. Home, in his experiments on this medicine, found that large doses brought on the strangury in women. Strangury is the frequent effect of spirit of turpentine taken for some time. 13* 142 HUNTER ON THE VENEREAL DISEASE. given either by the mouth or the anus; but they are more immediate in their effects in the form of clyster, especially the opium. Bark is often had recourse to in spasmodic affections, in which it is thought to be of service ; but in such affections of the urethra I think I have seen it frequently do harm. The external applications are, the steam of warm water with spirits, the pediluvium, the warm bath, bladders of warm water applied to the perinasurn, and similar applications. The crumb part of a new-baked loaf, warm from the oven, applied to the perinaeum, has been found to give ease. I have known a blister applied to the loins in a great measure remove the spasm from the urethra; it is equally effectual when applied to the perinasurn. But in most cases these methods are too tedious; therefore when the case has been of some standing, before assistance has been called for, and requires immediate relief, recourse should be had to the catheter or bougie immediately. If the contraction is near the bladder, the catheter will answer best; but in most cases the bougie will be sufficient, and is a much safer instrument; for in many hands the catheter is a very dangerous one, requiring a dexterity only to be acquired by a thorough knowledge of the course of the canal, and a habit of passing it. The bougie has likewise this advantage, that in many cases, where the part spasmodically affected will not allow it to pass, it may be allowed to lie close to the stricture; for it is not always necessary for the bougie to pass through the constrictured part: for a bougie which has only passed a very little way in the urethra has sometimes been effectual, if suffered to stay there till the desire of making water is perceived. In such cases, even when the bougie passes into the bladder, it is necessary to let it stay in the passage till the inclination to make water comes on. If the water does not follow on the first attempt, it will be proper to make another; or if only part follows the bougie, it will be necessary to introduce it again. This circumstance, of the water following the bougie with more certainty if it is allowed to stay till the inclination comes on, is a proof that the disposition in the bladder to contracting removes in some degree the disposition to contraction in the urethra. Some attention is necessary with respect to the passing of the bougie in these cases; for the urethra being more irritable than common, it often resists the bougie before it reaches the true spasmodic part. When this is the case, force is not to be used ; but we should rather wait a little with patience, and then make another attempt to push it on. Dipping the end of the penis in very cold water often removes the spasm, and the water flows immediately and freely. In most cases there is an uneasy sensation at the end of the penis, which leads the patient to rub those parts; and sometimes, though rarely, during the friction, the water will pass. Gently irritating injections, thrown in only a little way, often give ease. They may OF SOME OTHER AFFECTIONS OF THE URETHRA. 143

be supposed to act in a manner somewhat similar to a bougie that does not pass, and by irritating one part of the urethra to produce a relaxation in the other. They act in some cases as a preventive.

§ 3. Of the Paralysis of the Urethra.

In opposition to the foregoing disease, there is the want of power of contraction of the urethra; but this is not so frequent a case as the former. This disease is attended with symptoms contrary to those of the foregoing: the bladder is hardly allowed to be filled so as to give the stimulus of repletion, but the water dribbles away insensibly as fast as secreted by the kidneys; or if the bladder is filled so as to receive the stimulus for expulsion, then it immediately takes place, and the water flows, if the person does not act with the musculi acceleratores; but sometimes in such cases the power of contraction of these muscles is lost, and then the water will flow, whether the person will or not, there being little or no power of retention. There is great difference in the degrees of violence of this disease.

!j 4. Cure of the Paralysis of the Urethra.

It is to be cured by stimulants, as a blister to the loins, or a blister to the perinasurn. It may be useful to immerse the feet in cold water. Tincture of cantharides, taken internally, fifteen or twenty drops once or twice a day, according to the effects, are of singular service in some cases. A man came to St. George's Hospital with this complaint. I ordered him the before-mentioned medicine, and it had such an effect as to bring on the contrary disease, or a spasmodic affection of the urethra, so that he could not make water when he had the inclination ; but an injection of opium removed this complaint, and he was then well. In this case a few drops less, probably, would have effected a cure without any inconvenience.

\ 5. Of Caruncles cr Excrescences in the Urethra. Strictures are not supposed to be the only causes of obstruction to the passage of urine in this canal; excrescences or caruncles are likewise mentioned by authors as happening frequently. From the familiarity with which they talk of them, and the few instances in which they really occur, one would suspect that this cause of obstruction was originally founded in opinion, and not observation, and afterwards handed down as matter of fact. If caruncles had been at first described from actual examination of cases, the language would have accorded with the appearances, and they would have been considered as seldom the causes of obstruction compared with strictures. However, they do sometimes happen, although but rarely. I have in all my examinations of dead bodies seen 144 HUNTER ON THE VENEREAL DISEASE.

only two, and these were in very old strictures, where the urethra had suffered considerably. They were bodies rising from the surface of the urethra like granulations, or what would be called polypi in other parts of the body. It is possible they may be a species of internal wart; for I have seen warts extend some way into the beginning of the urethra, having very much the appearance of granulations. Most probably it will not be possible in the living body to distinguish caruncles, excrescences, or risings in the urethra, from a stricture; for I cannot conceive that they can produce any new symptoms, or peculiar feel to the examiner.

§ 6. Of the Cure of the Excrescence or Caruncle. I should very much suspect that this disease is not to be cured by the bougie; at least dilatation in such cases is not to be attempted, as there is no contraction. If therefore the bougie is of any use, it must be in making the carnosity ulcerate from its pressure, which probably may be done by a large bougie pressing upon it with considerable force. But if this should not have the desired effect, I should certainly recommend or use the caustic, if the parts are so situated as to admit of the application ; and from such practice I should not doubt of a cure. But the difficulty lies in distinguishing the disease from the true stricture; for although authors talk of caruncles as common, and give us the method of treatment, yet they have not told us how we are to distinguish them from strictures. I have never met with a caruncle in women. CHAPTER VIII.

OF THE SWELLED PROSTATE GLAND.

Another disease of the parts surrounding the urethra, which is often very formidable, is a swelling of the prostate gland. This is of more serious consequence than any of the former causes of obstruction, because we have fewer methods of cure ; for we cannot destroy it as we do the stricture, nor can Nature relieve herself by forming new passages ; we have, however, often the means of temporary relief in our power, which is not the case in the stricture ; for most conimonly we can draw off the water by the catheter. The swelling of the prostate gland is most common in the decline of life. The use of this gland is not sufficiently known to enable us to judge of the bad consequences that attend its diseased state, abstracted from swelling. Its situation is such, that the bad effects of its being swelled must be evident, as it may be said to OF THE SWELLED PROSTATE GLAND. 145

make a part of the canal of the urethra, and therefore when so diseased as to alter its shape and size, it must obstruct the passage of the urine. When it swells it does not lessen the surface of the urethra at the part like a stricture ; on the contrary, it rather increases it; but the sides of the canal are compressed together, producing an obstruction to the passage of the urine, which irritates the bladder and brings on all the symptoms in that viscus that usually arise from a stricture or stone. From the situation of the gland, which is principally on the two sides of the canal, and but little, if at all, on the fore part, as also very little on the posterior side, it can only swell laterally, whereby it presses the two sides of the canal together, and at the same time stretches it from the anterior edge or side to the posterior, so that the canal, instead of being round, is flattened into a narrow groove. Sometimes the gland swells more on one side than the other, which makes an obliquity in the canal passing through it. Besides this effect of the lateral parts swelling, a small portion of it, which lies behind the very beginning of the urethra, swells forwards like a point, as it were, into the bladder, acting like a valve to the mouth of the urethra, which can be seen even when the swelling is not considerable, by looking upon the mouth of the urethra from the cavity of the bladder in a dead body. It sometimes increases so much as to form a tumour,* projecting into the bladder some inches. This projection turns or bends the urethra forwards, becoming an obstruction to the passage of a catheter, bougie, or any such instrument; and it often raises the sound over a small stone in the bladder, so as to prevent its being felt. The catheter should for this part be more curved than is necessary for the other parts of the urethra. In such cases I have frequently passed first a hollow elastic catheter till it has reached this point, and afterwards a stilet or brass wire properly curved, so as to go over the prostate gland. The advantages of this method are, that if the hollow catheter passes, no more is necessary ; and, if it does not, the curved wire will pass along the hollow bougie much easier, both to the surgeon and patient, than it would have done if it had been introduced at first with the hollow bougie over it; for it would endeavour to adapt the urethra to the curve; whereas, when introduced afterwards, the stilet acts only on the inside of the hollow bougie, which the patient hardly feels. A gentleman had been often sounded for a stone, and yet no stone could be found ; but it afterwards appeared that there was a stone, which, together with the swelling of the prostate gland, had been the cause of his death. John Doby, a poor pensioner in the Charter-house, had been several years afflicted with the stone in the bladder, and was relieved from all the symptoms by an enlargement of this part of the prostate gland, preventing the stones from falling down upon the * Vide Plates IV. and VI. 146 HUNTER ON THE VENEREAL DISEASE. neck of the bladder and irritating those parts. A twelvemonth after that the symptoms of the stone had gone off, he was attacked with a strangury, to relieve which many ineffectual attempts were made, both with the bougie and catheter; but it soon proved fatal. Upon examination of the parts in the dead body, the prostate gland was found enlarged to a size six times greater than what it is in common, and the urethra, passing through it, was a slit about an inch and half in length, the two sides of which were close together, the upper end towards the pubes and the lower towards the rectum. This slit was formed by the sides of the prostate gland only swelling, and the right side was the most enlarged, having its surface next the urethra rounded or convex, and the left side was exactly fitted to it, having its surface hollowed in the same proportion. The small projecting point of the gland was so much enlarged as to come forwards into the cavity of the bladder, and fill up entirely the passage at the neck of it. The bladder itself was very much enlarged and thickened in its coats, and contained about twenty stones, most of them lying behind the projecting process of the prostate gland, and the rest lodged in small sacs, made by the internal membrane being pushed some little way between the fasciculi of muscular fibres. The prostate gland, when swelled, generally becomes firmer in its consistence. The effects of these swellings are very considerable, for they squeeze the side of the urethra close together, arid the projecting point hinders in some degree the urine from entering the passage, and in many cases stops it entirely. Further, the increased firmness of the substance of the gland hinders it from yielding to the force of the urine, so that little or none can pass. It will be unnecessary to relate the particular symptoms which this disease occasions; they are such us arise from any stoppage of urine, producing an irritable bladder. When a difficulty in making water takes place, a bougie is the instrument which the surgeon will naturally have recourse to, and if he finds the passage clear, which he often will, in such cases he may very probably suspect a stone. If search is made, and no stone felt, he should naturally suspect the prostate gland, especially if the sound or instrument used meets with a full stop, or passes with some difficulty just at the neck of the bladder. He should examine the gland. This can only be done by introducing the finger into the anus, first oiling it well, placing the fore part of the finger towards the pubes ; and if the parts, as far as the end of the finger can reach, are hard, making an eminence backwards into the rectum, so that the finger is obliged to be removed from side to side, to feel the whole extent of such a swelling, and it also appears to go beyond the reach of the finger, we may"be certain the gland is considerably swelled, and is the principal cause of those symptoms. I have known cases where the common catheter has been pushed through the projecting part of the gland into the bladder, and the OF THE SWELLED PROSTATE GLAND. 147

water then drawn off; but in one patient the blood from the wound passed into the bladder and increased the quantity of matter in it. The use of the catheter was attempted a second time, but, not succeeding, I was sent for. I passed the catheter till it came to the stop, and then suspecting that this part of the prostate projected forwards, I introduced my finger into the anus, and found the gland very much enlarged. By depressing the handle of the catheter, which of course raised the point, it passed over the projection; but unfortunately the blood had coagulated in the bladder, which filled up the holes'in the catheter, so that I was obliged to withdraw it, and clear it repeatedly. This I practised several days; but suspecting that the coagulum must in the end kill, I proposed cutting him as if for the stone; but he died before it could be conveniently done, and the dissection, after death, explained the case to be what I have now described. In some of those cases where this part of the gland swells into the bladder in form of a tumour, the catheter has been known not to bring off the water at times when it appeared to have passed; and upon the death of the patient, when the parts have been examined, it was imagined that the catheter, in the living body, had made its way into the tumour so as to have been buried in it at those times. * From the knowledge of the above-mentioned facts, whenever I find the urine does not flow immediately upon introducing the; catheter into the bladder, I have pushed it on and depressed the handle, so as to reach the fundus of the bladder with the end of the catheter, and have always succeeded. For the more ready introduction of the instrument, a catheter made flexible at the point only for about an inch is perhaps best, as it is more under the command of the hand than when wholly flexible. If the bougie be used, it should be first warmed, and then very much bent at the point, and allowed to cool in this position, and passed quickly with the concave side upwards, before it loses the bend in its passage. But the bougie does not answer so well as the catheter, because, upon withdrawing the bougie the sides of the gland soon close again. I have known where the water has passed by the side of the bougie with more freedom than when it was pulled out, because the bougie gave a straightness to this part of the canal, which it had not when the bougie was withdrawn. The following case is a strong instance of the inconveniences arising from such a disease of the prostate gland. A gentleman was attacked with a suppression of urine; a catheter could not be passed; but a bougie relieved him. He continued well for five years; but the same complaint returning, the bougie could not be passed, and the disease was supposed to be a stricture. A catheter however passed, although with a good deal of difficulty, and the bougie, though often tried, could not be passed, excepting • Vide Plate VI. 148 HUNTER ON THE VENEREAL DISEASE. once, just after using the catheter. I was sent for, and tried the bougie with as little success, and was obliged to have recourse to the catheter. I passed it with great ease, and the water was drawn off. The late Mr. Tomkyns, who had Daran's bougie, was called; but he was not more successful, and was obliged to have recourse to the catheter; but such violence was used as caused a good deal of blood to come from the urethra, and after all it did not succeed. I was again consulted, and passed the catheter, but with much more difficulty than before, which made me believe that the passage had been a good deal torn. Upon taking out the catheter, I passed a large bougie into the bladder with great ease; this I allowed to remain for three days, and the patient made water tolerably freely by the side of it. The moment I drew out the bougie I attempted to pass another, but did not succeed, although I gave it the natural bend of the passage. Upon withdrawing those bougies that did not pass, I observed that all of them had a bend at the point, contrary to the direction of the passage; this made me suspect that the place which stopped the bougie was on the posterior surface, and that by being pushed on, it bent forwards into the passage, and of course the point turned back. I therefore took a thick bougie, and before I introduced it I bent the point almost double, so that it could not catch at the posterior surface of the urethra, where I supposed the stop to be: this point of the bougie rubbed all along the anterior and upper surface of the urethra, by which means it avoided catching on the posterior surface, and it passed with great ease into the bladder. He made water by the side of the bougie, as before. He had been for some time troubled with fits of an intermittent, which at first were very irregular, but became afterwards more regular. In one of the cold fits, the bougie, being in the urethra, gave him great pain, and obliged him at last to pull it out, on which he had immediate ease. The sensation was as if it stretched the passage too much, and it seemed to come out with difficulty. This looks as if there was a contraction of the urethra, as well as of the vessels of the skin, in the cold fit; so that this disposition runs deep. By giving the bougie this bend he was able for the future to pass them with great ease. I may just observe, that by introducing the finger into the anus I found the prostate gland much enlarged. Many patients, while labouring under any of the before-mentioned diseases of the urethra, and sometimes even after they have been cured of them, find great pain in throwing forwards the semen, having a sensation as if it scalded. This arises from the very irritable state which the muscles of this part are in, giving great pain by their own action.

§1.0/" the Treatment of the Swelled Prostate Gland.

The methods practised in the above cases afforded only temporary relief, yet such must be had recourse to in order to prevent the consequences of retaining the urine too long. As a temporary OF THE SWELLED PROSTATE GLAND. 149 relief from pain, as also to remove spasm, opiate clysters should be thrown up once or twice a day. A certain cure, I am afraid, is not as yet discovered. I have seen hemlock of service in several cases. It was given upon a supposition of a scrofulous habit. On the same principle I have recommended sea-bathing, and have seen considerable advantages from it, and, in two cases, a cure of some standing. In one case in which I was consulted, the surgeon had found that burnt sponge had reduced the swelling of the gland very considerably. This disease, like the stricture, produces complaints in the bladder; but in this the bladder is generally more irritable, perhaps from the cause being nearer to that viscus. Diseases of the vesiculae seminales are very familiarly talked of; but I never saw one. In cases of very considerable induration of the prostate gland and bladder, where the surrounding parts have become very much affected, I have seen these bags also involved in the general disease ; but I never saw a case where it appeared that they were primarily affected. In a case of a swelled prostate gland, with symptoms of an irritable bladder, in a young gentleman about twenty years of age, Mr. Earle tried a blister to the perinaeum; but not finding the desired effect, and conceiving a greater irritation and dischage to be necessary, he passed a seton in the direction of the perinasurn. The orifices were about two inches distant from each other. The symptoms of irritability in the bladder began to abate, and in time went entirely off. Upon examination of the prostate gland, from time to time, it was found to decrease gradually till it was nearly of the natural size. The seton was continued some months, and upon its being withdrawn the symptoms began to return. It was advised to introduce it again, which was accordingly done, but without the former good effects.*

* [The enlargement of the prostate gland, as it occurs in old people, seldom, if ever, yields to surgical treatment: yet much may be done to prevent or alleviate the distressing effects which it produces on the neighbouring oro-ans. In fact, it is these effects only which give any importance to the malady. The disease of the prostate in most cases occasions no symptoms which are referrible to the gland itself. But it may impede the flow of the urine, or excite chronic inflammation of the bladder, and ultimately disease of the kidneys, or give rise to painful irritability of the rectum. The mode in which these consequences are produced, and the treatment by which they are to be obviated, are best detailed in the observations of Sir E. Home, on diseases of the prostate gland, to which work the reader is referred.] 14 150 HUNTER ON THE VENEREAL DISEASE. CHAPTER IX.

OF THE DISEASES OF THE BLADDER, PARTICULARLY FROM THE BEFORE- MENTIONED OBSTRUCTIONS TO THE URINE.

All the diseases of the urethra, as also the diseases of the prostate gland, I have now treated of, and shall next consider the effects of them upon the bladder, as also the diseases of that viscus, independent of affections of the urethra. The disease of the bladder arising from obstruction alone is increased irritability and its consequences, by which the bladder admits of little distention, becomes quick in its action, and thick and strong in its coats. But prior to the description of the effects of the diseases of the urethra on the bladder, it will be necessary, for the better understanding of the whole, to make some remarks upon those diseases of the two parts, in which we find that each affects the other; and these I shall consider without having any regard to the cause, but only to the general effects, when they are diseased. It may be observed, that every organ in an animal body is made up of different parts, the functions or actions of which are totally different from each other, although all tend to produce one ultimate effect. In most, if not in all, when perfect, there is a succession of motions, one naturally arising out of the other, which in the end produces the ultimate effect; and an irregularity alone in these actions will constitute disease, at least produce very disagreeable effects, and often totally frustrate the final intentions of the organs. I may be allowed also to premise, that the natural width of the urethra gives such a resistance to the force or power of the bladder in expelling the urine, as is easily overcome by the natural action of the bladder; but when the canal is lessened, either by stricture, spasm, swelled prostate gland, or any other means, this proportion is lost,'by which means the bladder finds greater difficulty than natural, and is of course thrown into an increased action to overcome the resistance, which becomes a cause of the irritability and increased strength of this viscus in such diseases. It is to be understood, that in a sound state of these two parts, the bladder and urethra, the contraction of the one produces a relaxation of the other, and vice versa ; so that their natural actions are alternate, and they may be considered as antagonist muscles to one another. Thus, when the stimulus of expulsion of the urine takes place in the bladder, which immediately produces contraction in it, the urethra relaxes, by which means the urine is expelled from the bladder, and allowed to pass through the urethra; and when the action ceases in the bladder, the urethra contracts armin OF THE DISEASES OF THE BLADDER. 151 like a sphincter muscle,* for the purpose of retaining the urine which flows into the bladder from the kidneys till it gives the stimulus for expulsion again. But in many diseases of these two parts this necessary alternate action is not regularly kept up, the one not obeying the summons of the other. This irregularity arises perhaps oftener from disease in the urethra than in the bladder, for the action of the urethra depends upon the actions of the bladder; and if it is not disposed to obey the notices of the bladder, then there must be an irregularity as to lime, which produces very troublesome symptoms. . , We find in many diseases of the urethra, such as strictures ana spasms, as also in diseases of certain parts belonging to this canal, such as the prostate and Cowper's glands, that there is a greater disposition in this canal for contraction than common, so that when the bladder has begun to act, the water is not allowed to flow, the urethra not immediately relaxing ; and the moment such a symptom takes place, every other power takes the alarm, and is brought in to assist the bladder, such as straining violently with the abdominal muscles and muscles of respiration, from all which there is violent pain in the parts immediately concerned, especially in the glans penis-t , This disease has different degrees of violence. When slight, the distance in time between the contraction of the bladder and the relaxation of the urethra is but short, only giving a momentary pain and straining, before the urethra relaxes, and the water flows according to the dilatation of the urethra, which, in many of these cases, is but very small. In others the distance of time is very long, many straining for a considerable time before a drop will come; and what does come is often only in drops; and sometimes before the whole urine can be expelled in this way, the spasm of the urethra comes on again, and there is a full stop, which gives excruciating pain for a while ; but at last the bladder is, as it were, tired, and ceases to act. But as the urine in such cases is seldom all discharged, and often but a very little of it, the symptoms soon recur; and in this way, with a call to make water perhaps every hour out of the four-and-twenty, the patient drags on a miserable life. , , The bladder, in all cases of obstruction, whether constant, as in the permanent stricture or swelled prostate gland, or only temporary, as in the spasmodic stricture, is generally kept distended, but much more so in the permanent stricture; and when the irritation

* It may be remarked, that many sphincter muscles have two causes of action ; one which may be called involuntary, depending on the natural uses and actions of the parts; the other is voluntary, where a greater degree of action can be produced by the command of the will : and when a diseased action takes place, it is probably of this voluntary action, for it is an increased action over the natural, which the voluntary is. f Added : " A gentleman, whose bladder was in an irritable state, found, that by passing a bougie a little way into the urethra the irritation was taken off from the bladder, and he could retain the urine several hours."—Home. 152 HUNTER ON THE VENEREAL DISEASE. of fulness comes on, which is very frequent, the contraction of that viscus becomes violent, in proportion to the resistance : the sympathetic contraction of the muscles of the abdomen takes place, and is also violent; yet the water at such times shall only dribble, and be discharged in small quantity; and in the spasmodic stricture often not a drop shall pass, so that the bladder is never entirely empty; and what does pass is no more than what is sufficient to take off the irritation of fulness, by which means these actions become more frequent, and consequently there is almost always a constant oozing of urine from the penis between the times of making water. This, however, is not always the case, for the bladder sometimes is so irritable as not to cease acting till it has evacuated the whole water; and even then it is not at ease, but still strains, though there is nothing to throw out, the action of the bladder becoming a cause of its own continuance. In all such affections of the bladder there is a sensation of pain and itching combined in the glans penis.* If the symptoms are more urgent than what can be accounted for upon the supposition of a stricture or disease of the prostate gland, a stone is to be suspected.

§ 1. Of the Treatment where the Actions of the Urethra and Bladder do not exactly alternate.

The cure, where the disease arises from spasm alone, consists in removing the disposition to over-action in the urethra, and the irritable disposition of the bladder when the urethra does not obey it. Perhaps opiate clysters, as a temporary means of relief, are the very best medicines that can be administered. I have known a blister to the loins, or to the perinasurn, remove the spasm, in a great measure, from the urethra. When the circumstance of the ultimate actions of these parts not being regular arises from stricture, swelled prostate gland, or any mechanical obstruction to the urine, then that cause must be removed, as has been fully described in the treatment of these diseases.

§ 2. Of the Paralysis of the Bladder from Obstruction to the Passage of the Urine.

We may observe that the bladder is a part easily deprived of its power of contraction ; for we find in many debilitating diseases and long illnesses from any cause, as fever, gout, and considerable local diseases which debilitate, that the bladder often becomes paralytic, and the water must be drawn off. We may also observe, when the bladder has been distended considerably, from whatever cause, so * Added : « In diseases of the bladder the constitution is sooner affected by symptoms of dissolution than from the same apparent degree of disease in other parts; the patient becomes drowsy, insensible, and soon dies."—Home OF THE DISEASES OF THE BLADDER. 153 as to have its contractile power destroyed, that there is a considerable extravasation of blood from the inner surface of the bladder, so that the water which is evacuated is often extremely bloody. I have seen, in cases where the patient has died with this obstruction upon him, that the inner membrane of the bladder has been almost black, being loaded with extravasated blood ; but this symptom of bloody urine goes off, as the bladder acquires again its power of contraction. In the diseases of the urethra, before described, when not properly, or in time, attended to, and in cases of stricture, where Nature has not been able to relieve herself, the water must of course be retained in the bladder, which is perhaps always productive of another disease, that is, the loss of the power of contraction of that viscus. Although this one effect, the retention of urine, arises from very different causes, as before related, yet immediate relief must be given in all of them, which can only be effected by the evacuation of water. According to the nature of the obstruction, the mode of the evacuation will be different, and will be of two kinds, one by the natural passage by means of a hollow tube, the other by an artificial opening made into the bladder. If the causes of suppression are either spasmodic affections of the urethra, a swelled prostate gland, inflammation in the surrounding parts of the urethra, or tumours pressing upon it, as happens in pregnant women, immediate relief may be procured by means of a catheter, because under such circumstances a catheter will most probably pass, the sides of the canal being merely forced together by spasm, or external pressure. A bougie, although it will also pass under such circumstances, will not answer so well, because a bougie must be withdrawn before the water can flow, which will allow the cause of the obstruction to exert again its full force; and if the spasm should not now exist, yet the bougie will not answer, unless there be a power of action in the bladder; for it is with difficulty that the urine can be made to pass through the urethra, by pressing the abdomen only. When the catheter is passed, it will be necessary to make the patient strain with his abdominal muscles, as also with his muscles of respiration, to squeeze out the water, the bladder having no power of contraction, and even this will not be sufficient, for it it will be necessary to press on the region of the pubes, with the hand, to make the water flow. In cases where there is a considerable degree of debility in the bladder, or in those cases where there is a considerable strangury and of long standing, and where a small quantity of urine in the bladder gives the stimulus of fulness to that viscus, which is always attended with considerable urgency to make water, and where only very small quantities are evacuated, the bladder not being emptied at each time of making it, and when a catheter, either rigid or flexible, can with readiness be passed, the question is, What is the best wav upon the whole to evacuate the water 1 There are three 14* 154 HUNTER ON THE VENEREAL DISEASE. ways in which it can be done: one, by allowing the parts to do their own business as much as they can, and this at first sight might be supposed to be the very best; but it is in some cases the very worst; for the frequency of the inclination to make water, arising from the water not being wholly evacuated each time, the evacuation not readily taking place, increases the effort, and for a few minutes produces excruciating pain, keeping up a considerable and almost constant irritation in all those parts, which few can bear. Another method is, to draw off the water each time with a catheter, but this in many cases is next to impracticable ; for supposing the operation to be performed only twice or three times in the day, we shall find that this is oftener than what should be done. The third method is, to leave the catheter almost constantly in the bladder. Which of these three methods is likely to give, on the whole, the least irritation must depend upon circumstances attending different cases. Where frequency and the urgency is great, and the flowing of the water difficult, either the second or the third is to be pursued ; and when the symptoms are such that a catheter must be passed very often, 1 believe it had better be left in, only taking it out occasionally. I think this is supported by observation and experience. It sometimes happens in cases of swelled prostate gland, that the catheter cannot be passed without the utmost difficulty, and when this has been the case 1 have left it in the bladder, for fear of not being able to pass it again, and continued it there till the bladder has sufficiently recovered its tone, which is known by its being able to throw the urine through the catheter; after which that instrument may be withdrawn. If the spasm, in such cases as arise from that cause, should still continue after the bladder has recovered its tone, we must continue the use of the catheter. But it often happens that the spasm leaves the urethra before the bladder recovers its power of contraction, the disease becoming then simply a paralysis of that viscus. One of the first symptoms of the bladder beginning to regain its power of contraction is, the sensation of fulness, or an inclination to make water, and when that sensation comes on the patient should be allowed to make water; but not to force it, for that circumstance alone will bring on the spasm if the urethra is not very ready to dilate. I have seen however in some cases, that a slight sensation is not altogether to be depended upon, for it required a little retention more effectually to stimulate the bladder to action, and then the water has passed more freely. The spasmodic contraction of the urethra does not appear to give up its action simply upon the stimulus or inclination to make water, not till the bladder begins to have the power of contraction; for in cases where the bladder is paralytic, and \et sensible of the stimulus arising from being full, as it does not contract, the urethra does not relax, and the water cannot be made to pass. It would appear, that, as the bladder recovers of the paralysis, it is not able to contain so much water as usual. Therefore the OF A SUPPRESSION OF URINE. 155

patients are obliged to make water often, and of course in small quantities.

§ 3. Of the Cure of the Paralysis of the Bladder, from Obstruction arising from Pressure or Spasm.

The removal of the causes of the paralysis of the bladder was fully described when we were treating of the diseases which produce that complaint, and the immediate relief, when the bladder is rendered inactive, has just now been considered ; the paralysis itself is therefore the only remaining thing to be attended to. In this disease there are often contrary indications of cure, for a spasm is very different from a paralysis; and if the suppression is from spasm, and that still continues, then what may be good for the paralysis, may be bad for the spasm. As in such cases the water can be drawn off, the bladder should be first attended to. Stimulants and strengtheners are useful; blisters to the loins to rouse the bladder to action, and blisters to the perinaeum, to take oft" the spasm from the urethra, often succeed. Electricity is sometimes of singular service, when applied in such cases to the perinasurn. Through the whole of the cure the urine must be drawn off frequently, because the bladder should not be allowed to be distended, which otherwise would be the consequence; and the sensation arising from the distention of that viscus is a very oppressive one. A gentleman was at times attacked with a difficulty in making water, which he paid no attention to, as it had always gone off; but at last he was obliged to have recourse to the catheter, which afforded only a temporary relief. The spasm continued, and I was sent for. When I passed the catheter, I was obliged to press the lower part of the abdomen to squeeze out the water, for the bladder appeared to give but little assistance. I ordered a blister to the loins, which gave some power of contraction to the bladder, and took off some of the spasm in the urethra, but still he was very little relieved. I then directed a blister to be applied to the perinasurn, which immediately removed his complaint.^ CHAPTER X.

OF A SUPPRESSION OF URINE--AND' OPERATIONS FOR THE CURE OF IT.

In cases of total suppression of urine arising from strictures, or other causes where a catheter cannot be passed, and where every other method recommended is impracticable, an artificial opening must be made into the bladder for the evacuation of the water. There are three places where this opening may be made, and each HUNTER ON THE VENEREAL DISEASE. has had its advocates. This operation has not been considered in all its circumstances in different patients, so as to direct the young surgeon in the variety of cases that may occur; for under some circumstances the operation is more advisable in one place than another; and indeed it may sometimes be next to impossible to perform it in a particular part. The opening may be made first in the perinasurn, where we now cut for a stone; secondly, above the pubes, where cutting for the stone was formerly practised ; and thirdly, from within the rectum, where the bladder lies in contact with the gut. The first question which naturally occurs, is, Which of those situations is the most proper for the safety of the patient, the evacuation of the water, and the conveniency of operating, when no particular circumstance forbids either of the situations? On the first view of the subject, one would be apt to prefer that above the pubes, or from the rectum, as the bladder is nearer to either, and the parts more adapted to an operation than from the perinaeum, where we must cut at random. These two situations, although the most proper in this respect, under certain circumstances, yet may become the most improper, for they are subject to greater changes than the perinasurn. The reasons that may render it very improper above the pubes are, the persons being very fat, or the bladders not distending sufficiently so as to rise above the pubes, which is common enough in diseases of those parts. In very fat people it will be found that the substance to be cut through may be three or four inches, which will not only make the operation very unpleasant, but often improper: for such thickness of parts will make the swell of the bladder very obscure and uncertain ; in many the bladder is so diseased as to allow of but little distension, and in such the symptoms of fulness come on very early, perhaps when there are only a few ounces of water collected. But if the retention has been for some considerable time, as twentyfour hours, then we may suppose that the bladder has allowed of distension to a much greater degree, which may in some cases be ascertained by introducing the finger into the rectum. But where the bladder distends, and the parts are so thin that it can be plainly felt above the pubes, I see no material objection to this situation ; and it has this advantage over the operation by the rectum, that a catheter can more easily be introduced, and kept in, which will be necessary to be done till the cause is removed. It may be necessary here to mention some precautions respecting the keeping the instrument in the bladder; as also the best kind to be used, It must be a hollow tube, and should reach as far as the posterior surface of the bladder, for upon the contraction of that viscus its anterior part recedes backwards and downwards from the abdomen towards its fixed point, which may draw the bladder off from the tube. But as the distance between the skin of the abdomen and posterior surface of the bladder cannot be exactly ascertained, the canula may be either too long, or too short; if too OF A SUPPRESSION OF URINE. 157 long, its end may press upon the posterior surface of the bladder and produce ulceration there, and in time work its way into the rectum. To avoid this mischief, as also the inconveniences arising from its being too short, and the bladder slipping off from its end, I would recommend the tube to be made with a curve, and to lie with its convex side on the posterior part of the bladder, which being a large surface, and following nearly the same curve as the canula, less mischief is to be expected. The openings into the canula may be made on the concave side. It would probably be both safer and easier for the patient, to have the curved end of the catheter introduced into the urethra from the bladder. The passing of it into the urethra is very practicable ; and we know that such a body lying in the urethra is not productive of any mischief. A common catheter passed in this way enters so far as to bring the handle almost flat to the belly ; at most only a little bolster between the catheter and belly is necessary, and then with a piece of tape fixed to the handle of the catheter it might be fastened to the body; or a short catheter might be made with ears to fix the tape to.* In cases where the canula has remained in the urethra some time, the artificial passage will become in some degree permanent, so that it may be taken out occasionally, and cleaned from any stony matter that may be attached to it. To avoid this part of the operation it has been recommended to have two canulas, one within the other, that by drawing out the inner it may be cleaned, and again introduced; but in most cases it will also be necessary to withdraw the outer one, as its external surface will contract a crust. The second method, or puncture by the anus, will more commonly admit of being performed than that above the pubes; for it does not require that distension of bladder which the other does, and is therefore not so often impracticable from that cause; and perhaps the only obstacle here is a swelled prostate gland. In many of these cases of diseases of the urethra, the prostate gland is very much swelled, which I can conceive may make the proper place for the puncture very uncertain; for the prostate gland, in such cases, will be pressed down towards the anus, before the bladder, and will be the first thing felt by the finger. Care must therefore be taken to distinguish the one from the other, which can only be done by getting the finger beyond the prostate gland, which may not be practicable; and, if practicable, it may not be an easy matter to distinguish the one from the other, as a thickened and distended bladder may seem to be a continuation of the same tumour. However if the objections given to the performing it above the pubes exist, I should prefer operating by the rectum : for although the

* Where this operation is performed in consequence of a stricture, I have conceived that by passing a catheter into the urethra from the bladder till it comes to the stricture, and then passing another straight canula from the glans down the urethra, that the two may nearly meet, only having the stricture between them ; and a piercer may be passed down and forced into the end of the one from the bladder, and afterwards either a bougie or hollow catheter introduced. 158 HUNTER ON THE VENEREAL DISEASE. probability of succeeding here may not be apparently greater than above the pubes, yet the chances are in its favour. I must however observe here, that the objections which I have started, are only raised in my own mind from my knowledge of the diseases of those parts, and not from cases of suppression of urine under all the before-mentioned circumstances having occurred to me in practice. A case of total suppression of urine arising from stricture, where no instrument could be passed by the natural passage, and where a puncture was made into the bladder, from the rectum, with success, is related in the Philosophical Transactions, by Dr. Hamilton of Kings-Lynn in Norfolk.* What led Dr. Hamilton to do it here, was a difficulty which was found in passing the clyster-pipe into the rectum, which induced him to introduce his finger into the anus, and he found the bladder so prominent in the rectum as to give the hint of performing the operation there. The man was put into the same position as in the operation for the stone, and a trochar was introduced upon the finger into the anus, and thrust into the lower and most prominent part of the tumour, in the direction of the axis of the bladder, and upon withdrawing the piercer the water flowed out through the canula. A straight catheter was then introduced through the canula, lest the orifice in the bladder should be drawn off from the canula. Then the canula was pulled out over the catheter, which was left in till the whole water was evacuated, and was then withdrawn. The bladder, notwithstanding this perforation, retained the water as usual, till the inclination to make it came on ; and when he performed the action of making water, the orifice in the bladder seemed to open, and it rushed out by the anus. This continued about two days, when the water began to find its natural passage, and a bougie was introduced into the bladder, through the urethra, which gave a free passage for the water, and of course less came by the anus; so that on the sixth day after the operation the whole came by the natural passage. The man continued the use of the bougie till the stricture was dilated. Dr. Hamilton further remarks, that in those cases of suppression of urine, in general, he has found that calomel and opium, in large doses, answer better than anything he has tried. He is convinced, from repeated trials, that the specific efficacy is in the calomel, as large doses of opium alone have proved ineffectual ; but he does not say that calomel alone will answer. He orders ten grains of calomel with two of opium, to be repeated in six hours if it has not answered in that time; and he says he has seldom been obliged to give a third dose. This method of tapping the bladder was first suggested by Mons. Fleurant, surgeon to the Charite, at Lyons, in the year 1750. The operation was performed at that time, and an account of it was

* Philosophical Transactions for the year 1776, vol. lxvi. p. 578. OF A SUPPRESSION OF URINE. 159 afterwards published by Mons. Pouteau, in 1760, with the history of three cases, in all which the operation was performed by Mons. Fleurant. The propriety of performing the operation in this part occurred to him in a manner similar to that before related of Dr. Hamilton ; for in introducing the finger into the rectum to examine the state of the bladder in a case where he was going to puncture in the perinaeum, he found the bladder so prominent there, and so much within the reach of his instrument, that he immediately altered his intention, and performed it in this part. He very readily drew off the water, and kept the canula in, with a T bandage, till the urine came the right way, and then withdrew it, and all terminated well. But there was a good deal of trouble on account of the canula being left in on going to stool, as also from the constant dribbling of the water through it; all of which was prevented in Dr. Hamilton's case, by removing the canula immediately upon the evacuation of the water. This was productive of another good effect, which was the retention of the urine till the stimulus ot tillness was given, and then it passed through the artificial as it would throuo-h a natural passage. Should this be a constant effect in consequence of performing the operation here, I think it must be owned to be an unexpected circumstance which at first could not have been imagined.* . In another patient of Mons. Fleurant's, the canula was kept in the anus and bladder thirty-nine days, without any inconvemency; so that the objection to this part of the operation cannot be material. Pouteau mentions one case where he performed this operation, in the year 1752, and the man died.f He says: "I was called to visit a poor man suffering under a retention of urine, so obstinate and violent that it had already the symptoms of what is called a reflux of urine into the blood ; and the complaint had continued more than three days. An empiric, to whose care he had been entrusted, after having very improperly given him the most powerful diuretics, had likewise the rashness to search him. It appears probable that these attempts, which were made without success, must have increased the mischief. A catheter could not be passed into such parts by unskilful hands without increasing the inflammation. I only made three slight efforts to effect a passage into the bladder by the urethra, which appeared to be much diseased, as well by the effusion of blood as the extreme pain which these attempts produced. I determined at once to do as before, and plunged my trochar by the rectum into the bladder. The success was exactly the same; the bladder was entirely emptied, and I allowed the canula to remain there a whole night and a day, during which time the urine flowed without intermission. Everything went on without any accident which could be supposed connected with the opera- * A history, with a description of this operation, was published by Mr. Reid, rtreon, of Chelsea, in 1778. f Pouteau, Melanges de Chuurgie, printed at Lyons, 1760, p. 506—50S. 160 HUNTER ON THE VENEREAL DISEASE. tion ; and death, which happened next day, was entirely independent of it." One must suppose, with Pouteau, that the death of the patient could not have arisen from this operation, but from the preceding diseases. The bags called vesiculaa seminales, and the hemorrhoidal vessels, have been mentioned as parts in danger of being wounded in the operation, and thereby proving troublesome ; but if either of them are wounded, no inconvenience can arise. To avoid the vesiculas seminales it is recommended to perforate high up, and directly in the middle of the bladder, between the two sides ; and this situation is, at the same time, the one where the hemorrhoidal vessels are the smallest, and therefore it is of less consequence if they are wounded. It must appear from the following case, sent me by a gentleman, that a communication being kept up between the bladder and rectum is only inconvenient, and not so much so as might be expected. " With respect to the sailor who passed his urine by the rectum, I have examined the few papers by me, but cannot find the particular remarks I made; however, as the case was singular, I recollect the man told me that, a few years before, (this was at Madras Hospital, in December 1779.) he had the venereal disease, very bad and very long: that the urine came by the anus, but this passage healed up, and it came by the penis, and continued to do so till he caught the disease again, when the urine found its way a second time by the anus, and came that way for years. When he first came under my care, in the hospital at Bombay, February 1779. he felt no uneasiness or inconvenience from this manner of passing his urine : whenever he had an inclination to make water he sat down. I often made him lie upon his breast, with his legs drawn up, and the stream came through the anus with great force."* In other cases, in consequence of abscesses forming between the bladder and rectum, where they have not healed up, there has been a reciprocal passing of the contents of these cavities from the one to the other. It only remains to speak of the puncture in the perinasurn. An

* Added: "John Conway, a seaman belonging to St. Antonio, was admitted into Haslar Hospital on the 24th November 1770, for the lues venerea. Besides the usual symptoms of that disease he had a communication between the bladder and rectum, which had continued four months. When he endeavoured to make water, the water flowed both from the urethra and anus, coming from the anus in a small stream, often to the quantity of a pint. It also flowed freely from the anus when he went to stool, although none was voided by the urethra. In the beginning of the complaint, some portions of dead flesh, he said, had come away from the rectum, but when admitted into the hospital there was not any soreness remaining, or discharge of matter from it, and the urine passed without pain : externally he never had any fistula penetrating either into the bladder or rectum, and when disturbed with flatulence in the bowels, did not perceive any wind to escape from the urethra."—Home. OF A SUPPRESSION OF URINE. 161 obstruction to the urine taking place in the natural passage prevents us from introducing an instrument in most of those cases, and deprives us of all the advantages we could receive from it as a guide in the operation; yet there may be cases of stricture where, by cutting into the urethra beyond the stricture, the water will flow; but this must be done without any guide or direction, and requires a nice and accurate knowledge of the parts. Or if the obstruction arises from the valvular projection of the prostate gland, a staff may be passed as far as this projection, and cut upon as for the stone, the surgeon only making a similar incision, using a small gorget, or, in the room of that, a trochar of a particular form might be run along it into the bladder; for although the staff does not enter the bladder, yet the distance to pass through without this guide is but small. If this cannot be done, a small and deep incision may be made in the perinasurn, with an imposthume lancet towards the bladder; the point of the trochar is to be introduced by this, the surgeon passing at the same time the forefinger of the other hand into the anus, which will be a guide both for the direction of the instrument, as also to avoid its point passing into the rectum. With these precautions the error cannot be great. I must own, however, that I have not seen cases enough to enable me to give all the varieties that commonly happen, and of course to give all the advantages and disadvantages of each, method.*

* [In cases of retention of urine from stricture, it is always more safe to open the urethra than to puncture the bladder. The bladder is imbedded in loose cellular membrane, which envelopes it everywhere, and which must be wounded if the bladder is punctured, whatever part be chosen for that operation. Now such a wound cannot be made without great danger, because the urine is thus admitted into this loose cellular texture, and frequently diffuses itselt through it, producing extensive sloughing and abscess. This is by no means a rare consequence of puncture of the bladder, and when it occurs, is very generally fatal, ine opening of the urethra is not attended with the same risk, because the cellular membrane of the perinaeum is generally loaded with fat. and the escape of the urine is in all cases direct and easy ; and even if abscess should take place, it will be near the surface, and can be laid open with the greatest facility. Under ordinary circumstances the urethra is collapsed, and is not easily found, unless some instrument is previously introduced as a guide : but in cases of retention of urine from stricture, it is always greatly dilated between the contracted part and the bladder, and there is not the same difficulty. As there is variety in the seat of stricture, there will be some variety also in the operation which is

re<When the obstruction is situated before the bulb, the distension of the urethra behind it may be distinctly felt in the perinaeum, especially when the patient is strainintr to pass water. Under such circumstances nothing is easier than to open the dilated part of the passage with a common lancet. But the stricture is much more frequently seated at the part where the membranous portion of the canal enters the bulb. In this case the difficulty is greater Nevertheless, the dilated part of the urethra may generally be felt trough the rectum, and more or less distinctly in the perineum; and if a previous'incision be made, as in lithotomy, through the superficial parts, it may be reached, and Ui^fn The ooerator may derive some assistance from the introduction of a l^dTnt'o thl uretC: as SrL the stricture, which will point out the direction 15 162 HUNTER ON THE VENEREAL DISEASE. § 1. Of allowing a Catheter to remain in the Urethra and Bladder,

In cases of debility of the bladder, and where a catheter passes with difficulty, or with great uncertainty, and in cases where it must be used frequently, and for a length of time, it will be necessary to keep an instrument in the urethra and bladder, so as to allow the water to pass through it freely. A common catheter, or one made of the elastic gum, is perhaps the best instrument; but it must be fixed in the canal: this will be best done by its outer end being tied to some external body, as I shall now describe. When the catheter is fairly in the bladder, the outer end is rather inclined downwards, nearly in a line with the body. To keep it in this position we may take the common strap or belt-part of a bag-truss, with two thigh-straps either fixed to it or hooked to it, and coming round each thigh forwards by the side of the scrotum, to be fastened to the belt where the ears of the bag are usuall fixed. A small ring or two may be fixed to each strap just where it passes the scrotum or root of the penis; and, with a piece of small tape, the ends of the catheter may be fixed to those rings, which will keep it in the bladder. A bit of rag about four or five inches long, with a hole at the end of it, passed over the exterior end of the catheter, and the loose end allowed to hang in a bason, placed between the thighs, will catch the water which cannot disengage itself from the catheter, and keep the patient dry ; or if another curved pipe is introduced into the catheter it will answer the same purpose. Under such treatment the bladder will never be allowed to be distended ; and when the patient wants to have the bladder some degree emptied, he has only to strain with his abdominal muscles, by which means he will be able to throw out a great deal at each time. As the bladder begins to recover its actions, the patient will find

of the canal ; but his principal guide must be the position of the pubes, since in this case the part which is to be punctured will lie immediately below the symphysis. When the contraction is still further back, so as to be near the apex of the prostate gland, it may be impossible to feel any dilatation; and in this case the operation must be varied. A staff should be first introduced into the urethra, and passed down to the stricture. The groove of the staff should then be laid open for a small extent near its point, and this will enable the operator to introduce a probe, which may be passed on to the stricture, and, without much trouble, made to penetrate it. When that has been effected, it will not be difficult to pass a catheter through the stricture into the bladder, and to draw off the water. These operations are not applicable to cases where the obstruction arises from an enlarged prostate gland. In this case the mouth of the urethra is closed, and no urine is admitted into it: yet even here the operation of puncturing the bladder is more hazardous than the perforation of the enlarged prostate. A silver catheter may be forced forward through the prostate, and carried into the cavity of the bladder; and this has been done on several occasions, without being followed by serious consequences, or even by material inconvenience. The opening thus made has sometimes been permanent; at other times it has appeared to close, and the urine has been passed in the same manner as before the operation, and with equal facility.] OF A SUPPRESSION OF URINE. 1G3 that an inclination to make water will come on, and at those times he will also find that the water will come from him without straining with the abdominal muscles; when this takes place readily, the catheter may be taken out, and it will be found that he will be able in future to make water of himself. If it is necessary to keep in the catheter a considerable time, it will be the cause of a great deal of slime and mucus being formed in the urethra and bladder; but I believe this is of no consequence. I have known a catheter kept in this way for five months without any inconveniency whatever. In all cases where it is necessary to keep an extraneous body for a considerable time in the bladder, whether in an artificial passage or the natural one, it will be proper a few days after its first introduction to withdraw it, and examine whether it is incrusting, or fillino- up in its cavity with the calculous matter of the urine. If, after°remaining in the bladder for some days, it has contracted none, we need be under no apprehension of its doing it; but if, as frequentlv happens, it should have collected a considerable quantity, then it will be necessary to have it occasionally withdrawn and cleaned. The best method probably of doing this is to put it in vinegar, which will soon dissolve the stony matter.

^ 2. Of the increased Strength of the Bladder.

The bladder, in such cases as have been described, having more to do than common, is almost in a constant state of irritation and action ; by which, according to a property in all muscles, it becomes stronger and stronger in its muscular coats; and I suspect that this disposition to become stronger from repeated action, is greater in the involuntary muscles than the voluntary; and the reason why it should be so is, I think, very evident: for in the involuntary muscles the power should be in all cases capable of overcoming the resistance, as the power is always performing some natural and necessary action; for whenever a disease produces an uncommon resistance in the involuntary parts, if the power is not proportionally increased, the disease becomes very formidable; whereas in the voluntary muscles there is not that necessity, because the will can stop whenever the muscles cannot follow; and if the will is so diseased as not to stop, the power in voluntary muscles should not increase in proportion. I have seen the muscular coats of the bladder near half an inch thick, and the fasciculi so strong as to form ridges on the inside of that cavity; * and I have also seen the fasciculi very thin, and even wanting in some parts of the bladder, so that a hernia of the inter-

* This appearance was long supposed to have arisen from a disease of that viscus- but upon examination I found that the muscular parts were sound and distinct, that they were only increased in bulk in proportion to the power they had to exert, and that it was not a consequence of inflammation, for in that case parts are blended into one indistinct mass. 164 HUNTER ON THE VENEREAL DISEASE. nal coat had taken place between the fasciculi and formed pouches.* These pouches arise from the thin parts not being able to support the actions of the strong; as happens in ruptures at the navel or rings of the abdomen.

§ 3. 0/ the Distention of the Ureters.

It sometimes happens that the irritation from the distention of the bladder, and the difficulty in throwing out its contents, is so great that the urine is prevented from flowing freely into that viscus from the ureters, which become thereby preternaturally distended. The pelvis of the kidneys and infundibula are also enlarged ; but how far this dilatation of the ureters and pelvis is really owing to a mechanical cause I am not so clear, or whether it is not a disposition for dilatation arising out of the stimulus given by the bladder. In some cases of long standing where the bladder was become very thick, and had been for a long time acting with great violence, it had affected the mamillas, so that the surface of these processes produced a matter, and perhaps even the secreting organs of the kidneys, so that the urine secreted was accompanied with a pus, arising from the irritation being kept up in all these parts. The urine in the above cases is generally stale, even before it is thrown out of the bladder, which when joined with the circumstance of the linen being constantly kept wet, by the almost continual discharge of urine, becomes very offensive, and it is hardly possible to keep the patient sweet.

§ 4. Of Irritability in the Bladder independent of Obstructions to the Passage of the Urine.

Another disease of the bladder, connected with the present subject, is, where that viscus becomes extremely irritable, and will not allow of its usual distention. The symptoms of this disease are very similar to those arising from obstructions to the passage of the urine in the urethra, but with this difference, that in the present disease the urine flows readily, because the urethra obeys the summons and relaxes; however, there is often considerable straining, after the water is all voided, arising from the muscular coat of the bladder still continuing its contractions. This irritability of the bladder often arises from local causes, as a stone, cancer, or tumours forming on the inside, all which produce irritability of this viscus. In such cases the straining is violent, for the cause still remains which continues to give the stimulus of something to be expelled, and the bladder continues to contract

* This is perhaps the cause of the stone being often found in a pouch formed in the bladder: for the bladder in cases of stone is often very strong, which arises from the violent contraction of that viscus, caused by the irritation of the stone on the sides of it; and also from the stone being often opposed to the mouth of the urethra in the time of making water. OF A SUPPRESSION OF URINE. 165 till tired, as in the cases of simple irritability, and then there is a respite for a time; but this respite is of short duration, for the urine is soon accumulated. This disease will in the end be fatal by producing hectic fever.

§ 5. Of the Cure of simple Irritability of the Bladder.

When the symptoms arise from irritability alone, and not from a stone or any local affection, the nature of the complaint may not at first be so obvious ; temporary relief may, however, be procured bv opium, which is most effectual in slight and recent cases ; and if it'be applied as near to the part as possible, its effects will be more evident; and therefore it may be given by clyster as well as by the mouth.* I should, however, be rather inclined to rely on a blister applied to the perinasurn, or to the lower part of the small of the back, or upper part of the sacrum if more convenient, than to any other method of cure. In all cases, where there is an irritation of the bladder, the patient should never endeavour to retain his water beyond the inclination to make it. It hurts the bladder and increases its irritability; and indeed I am apt to think that this circumstance, even in sound parts, is often a predisposing cause of disease in this viscus and its appendage, the urethra: for I have known several cases where it has brought on the spasmodic stricture in the urethra in sound parts, and it is frequently an immediate cause of strangury in those who have either a stricture or a disposition to spasms in those parts. A gentleman in perfect health, from retaining his urine beyond the inclination, in the playhouse, had all the symptoms of an irritable bladder brought on, which continued for several years, rendering him miserable.

^6. Of a Paralysis of the Acceleratores Urines.

In many irritations of the bladder, the urethra not only relaxes directly on the stimulus to make water being felt in that viscus, as has been described, but a paralysis sometimes takes place in the voluntary muscles of those parts, so that the will cannot command them to contract to hinder the inconveniences that may attend an immediate evacuation of that fluid. If we attempt to stop the water, which is an act of the will, it is in vain; the acceleratores will not obey, and the water flows. A blister applied to the perinasurn will have considerable effects in removing this complaint.

* Added : "I have known alum whey given, under which treatment the patient got well."—Home. 15* 166 HUNTER ON THE VENEREAL DISEASE. CHAPTER XI.

OF THE DISCHARGE OF THE NATURAL MUCUS OF THE GLANDS OF THE URETHRA.

The small glands of the urethra and Cowper's glands secrete a slimy mucus, similar to the white of an egg not coagulated. This seldom appears externally, or flows from the urethra, but during the indulgence of lascivious thoughts, and is seldom or never attended to, excepting by those who are either under apprehensions of a gonorrhoea coming on, or imagine the last infection is not gone off entirely, and are therefore kept in constant terror by this natural discharge. They often find it in such quantity as to leave spots on the shirt, but without colour; and often after toying, the lips of the urethra are, as it were, glued together by it, from its drying there, which appearances alarm the mind of the patient without cause. Although this is only a natural discharge, and is secreted, at such times, under the same influence which naturally produces it, it must be owned that it is commonly much increased in those cases of debility arising from the mind, which is probably not easily to be accounted for. It would seem that the contest between the mind and the body increases this secretion, for it cannot be considered as a disease of the parts.

§ 1. Of the Discharge of the Secretions of the Prostate Gland and Vesiculce Seminales.

This complaint is imagined to be the consequence of the venereal disease in the urethra; but how far this is really the case is not certain, though most probably it is not. It is a discharge of mucus by the urethra which generally comes away with the last drops of urine, especially if the bladder is irritable, and still more at the time of being at stool, particularly if the patient be costive, for under such circumstances the straining or actions of the muscles of those parts are more violent. It has generally been supposed that this discharge is semen, and the disease is called a seminal weakness; but it appears, from many experiments and observations, that the discharge is undoubtedly not semen. It is only the mucus secreted either by the prostate gland, by those bags improperly called vesiculas seminales, or both; and it may not be improper to give here the distinguishing marks between these two fluids. First, we may observe the discharge in question is not of the same colour with the semen, and is exactly of the colour of the mucus of the prostate gland and of those bags. It has not the same smell, and indeed it hardly has any smell at all. The quantity, evacuated at one time OF THE DISCHARGE OF THE NATURAL MUCUS, ETC. 167

is often much more considerable than the evacuation of semen ever is, and it happens more frequently than it could possibly do were the discharge semen. It is a disease that often attacks old men, where one can hardly suppose much semen to be secreted; and we find that those who are affected with this disease are no more deficient in the secretion and evacuation of the semen, in the natural way, than before they had the disease. If the mind be at ease, this shall take place immediately after a discharge of semen as well as before, which could not be the case were it. semen. Further, if those that labour under this complaint are not connected with women they are subject to nocturnal discharges from the imagination, as persons who are perfectly sound: and indeed most patients, when made acquainted with these circumstances, become very sensible that it is not the semen.* It is not clear what the diseased state of the parts is upon which this discharge depends, whether there is a larger secretion of this mucus than natural, or whether it is entirely owing to a preternatural uncommon action of those parts; and if this last, why these parts should be put into action when the bladder, rectum, and abdominal muscles are thrown into action to expel their contents, is not easily explained. It is plain that the most violent actions of these parts are necessary to produce this evacuation ; for it does not come with the first of the urine, nor in general with an easy stool. As it was thought to be a seminal dischage, it was imagined to arise from a weakness in the organs of generation ; and as frequent discharges of the semen in the natural way generally weaken, it was therefore imagined that this discharge must also weaken very considerably; and the imagination will operate so strongly as to make the patients believe they really are weakened. Whether the cause of such a discharge is capable of weakening, I will not pretend to say; but I believe that the discharge simply does not. Fear and anxiety of mind may really weaken the patient. In the cases I have seen of this kind the mind has been more affected than the body. From my own practice, I can hardly recommend any one medicine, or way of life, for removing this complaint. In one case I found considerable benefit from giving hemlock internally. The idea that has been formed of the disease leads to the practice generally recommended, such as giving strengthening medicines of all kinds; but I never saw any good effects from any of them, and I should rather be inclined to take up the soothing plan to prevent all violent actions. Keeping the body gently open will in some degree moderate the discharge, and probably may effect a cure in the end.

* Added • " A gentleman has often a discharge of mucus from the urethra with the last drops of urine, and when he goes to stool. But after having connexion with women it does not take place."-—#o'«e. 168 HUNTER ON THE VENEREAL DISEASE. CHAPTER XII.

This complaint is by many laid to the charge of Onanism at an early age ; but how far this is just it will in many cases be difficult to determine ; for, upon a strict review of this subject, it appears to me to be by far too rare to originate from a practice so general. How far the attributing to this practice such a consequence is of public utility, I am doubtful, particularly as it is followed most commonly at an age when consequences are not sufficiently attended to, even in things less gratifying to the senses; but this I can say with certainty, that many of those who are affected with the complaints in question are miserable from this idea; and it is some consolation for them to know that it is possible it may arise from other causes. I am clear in my own mind that the books on this subject have done more harm than good. In the cases of this kind that have come under my care, although the persons themselves have been very ready to suppose that the disease has arisen from the cause here alluded to, yet they did not appear to have given more into the practice than common; and, in particular, the worst case I have ever seen was where but very little of this practice had ever been used, much less than in common among boys.* Nothing hurts the mind of a man so much as the idea of inability to perform well the duty of the sex. If his scrotum hangs low it makes him miserable; he conceives immediately that he is to be rendered incapable of performing those acts in which he prides himself most. It is certain that the relaxation or contraction of the scrotum is in some degree a kind of sign of the constitution ; but it is of the constitution at large, not of those parts in particular. Nurses are so sensible of the contraction of that part being a sign of health in the children under their care, that they take notice of it. The relaxation of it in them cannot be supposed to arise from inability to perform those acts at one time more than another. The face is one of the signs of the constitution, and has as much to do with those peculiar acts as the scrotum. However, we must allow that this part is much more lax than what we should conceive was intended by Nature, even in young men who are well in health ; but as this is very general, I rather suspect that it arises from the circumstances of the part being kept too warm, and

* Added : " which is particularly pernicious from the frequency of the repetition, there being no want of opportunity."—Home. OF IMPOTENCE. 169 always suspended, the muscles hardly ever being allowed to act, so that they have less force. How far it is the same in those countries where the dress does not immediately suspend those parts, I have not been able to ascertain. Warmth appears to be one cause, for we find that cold has generally an immediate effect; but this is perhaps owing to its not being accustomed to cold, which if it were, it might possibly become as regardless of it as it is of warmth. What the difference is in this part, in a cold and warm climate, all other circumstances the same, I do not know. But whatever may be the cause, if it is really in common more lax than intended by Nature, it is of no consequence as to the powers of generation. The testicles will secrete, whether kept high or low.*

§ 1. Of Impotence depending on the Mind.

As the parts of generation are not necessary for the existence or support of the individual, but have a reference to something else, in which the mind has a principal concern, a complete action in those parts cannot take place without a perfect harmony of body and of mind; that is, there must be both a power of body and disposition of mind; for the mind is subject to a thousand caprices, which affect the actions of these parts. m Copulation is an act of the body, the spring of which is in the mind; but it is not volition; and according to the state of the mind so is the act performed. To perform this act well, the body should be in health, and the mind should be perfectly confident of the powers of the body; the mind should be in a state entirely disengaged from everything else; it should have no difficulties, no fears, no apprehensions; not even an anxiety to perform the act well; lor even this anxiety is a state of mind different from what should prevail ; there should not be even a fear that the mind itself may find a difficulty at the time the act should be performed. Perhaps no function of the machine depends so much upon the state of the mind as this. . . , . The will and reasoning faculty have nothing to do with this power ; they are only employed in the act, so far as voluntary parts are made use of; and if they ever interfere, which they sometimes do, it often produces another state of mind, which destroys that which is proper for the performance of the act; it produces a desire, a wish, a hope, which are all only diffidence and uncertainty, and create in the mind the idea of a possibility of the want ol success, which destroys the proper state of mind, or necessary confidence. . ir There is perhaps no act in which a man feels himseli more m-

* TSir E Home has here added a note, in which he expresses the helief that Onanism is more hurtful than the author imagined, and that its being practised Xe the parts have arrived at maturity in weakly constitutions, may prevent Sever attaining their full power and development. This opinion i. not only jn itself reasonable, but seems also to be confirmed by experience.] 170 HUNTER ON THE VENEREAL DISEASE.

terested, or is more anxious to perform well, his pride being engaged in some degree, which, if within certain bounds, would produce a degree of perfection in an act depending upon the will, or an act in voluntary parts; but when it produces a state of mind contrary to that state, on which the perfection of the act depends, a failure must be the consequence. The body is not only rendered incapable of performing this act, by the mind being under the above influence, but also by the mind being perfectly confident of its power, but conscious of an impropriety in performing it; this, in many cases, produces a state of mind which shall take away all power. The state of a man's mind, respecting his sister, takes away all power. A conscientious man has been known to lose his powers on finding the woman he was going to be connected with unexpectedly a virgin. Shedding tears arises entirely from the state of the mind, although not so much a compound action as the act in question; for none are so weak in body that they cannot shed tears; it is not so much a compound action of the mind and strength of body, joined, as the other act is; yet if we are afraid of shedding tears, or are desirous of doing it, and that anxiety is kept up through the whole of an affecting scene, we certainly shall not shed tears, or at least not so freely as would have happened from our natural feelings. From this account of the necessity of having the mind independent respecting the act, wre must see that it may very often happen that the state of mind will be such as not to allow the animal to exert its natural powers; and every failure increases the evil. We must also see from this state of the case, that this act must be often interrupted ; and the true cause of this interruption not being known, it will be laid to the charge of the body, or want of powers. As these cases do not arise from real inability, they are to be carefully distinguished from such as do ; and perhaps the only way to distinguish them is to examine into the state of mind respecting this act. So trifling often is the circumstance which shall produce this inability depending on the mind, that the very desire to please shall have that effect, as in making the woman the sole object to be gratified. Cases of this kind we see every day, one of which I shall relate, as an illustration of this subject, and also of the method of cure. A gentleman told me that he had lost his virility. After above an hour's investigation of the case, I made out the following facts. That he had, at unnecessary times, strong erections, which showed that he had naturally this power; that the erections were accompanied with desire, which are all the natural powers wanted ; but that there was still a defect somewhere, which I supposed to be from the mind. I inquired if all women were alike to him ; his answer was, no; some women he could have connexion with as well as ever. This brought the defect, whatever it was, into a smaller compass; and it appeared there was but one woman that produced this inability, and that it arose from a desire to perform OF IMPOTENCE. 171 the act with this woman well, which desire produced in the mind a doubt, or fear of the want of success, which was the cause of the inability of performing the act. As this arose entirely from the state of the mind, produced by a particular circumstance, the mind was to be applied to for the cure; and I told him that he might be cured if he could perfectly rely on his own power of self-denial. When I explained what I meant, he told me that he could depend upon every act of his will, or resolution ; I then told him, if he had a perfect confidence in himself in that respect, that he was to go to bed to this woman, but first promise to himself that he would not have any connexion with her for six nights, let his inclinations and powers be what they would, which he engaged to do, and also to let me know the result. About a fortnight after he told me that this resolution had produced such a total alteration in the state of his mind that the power soon took place; for instead of going to bed with the fear of inability, he went with fears that he should be possessed with too much desire, too much power, so as to become uneasy to him, which really happened; for he would have been happy to have shortened the time; and when he had once broke the spell, the mind and powers went on together, and his mind never returned to its former state.*

§ 2. Of Impotence from a Want of proper Correspondence between the Actions of the different Organs.

I lately observed, when treating of the diseases of the urethra and bladder, that every organ in an animal body, without exception, was made up of different parts, whose functions, or actions, were totally different from each other, although all tending to produce one ultimate effect. In all such organs, when perfect, there is a succession of motions, one naturally arising out of the other, which in the end produces the ultimate effect; and an irregularity alone in these actions will constitute disease, at least will produce very disagreeable effects, and often totally frustrate the final intention of the organ. I come now to apply this principle to the actions of the testicle and the penis; for we find that an irregularity in the actions of these parts sometimes happens in men, producing impotence ; and something similar, probably, may be one cause of barrenness in women. In men the parts subservient to generation may be divided into two, the essential and the accessory. The testicles are the essential ; the penis, &c, the accessory. As this division arises from their uses or actions in health, which exactly correspond with one another; a want of exactness in the correspondence, or susceptibility of those actions, may also be divided into two: where the actions are reversed, the accessory taking place without the first,

* Added : " Several similar instances have come under my care, but there is an evident objection to multiplying unnecessarily cases of this kind."—Home, 172 HUNTER ON THE VENEREAL DISEASE. or essential, as in erections of the penis, where neither the mind nor the testicles are stimulated to action; and the second is where the testicle performs the action of secretion too readily for the penis, which has not a corresponding erection. The first is called priapism, and the second is what ought to be called seminal weakness. The mind has considerable effect on the correspondence of the actions of these two parts; but it would appear in many instances that erections of the penis depend more on the state of the mind than what the secretion of the semen does; for many have the secretion, but not the erection; but in such the want of erection appears to be owing to the mind only. Priapism often arises spontaneously, and often from visible irritation of the penis, such as the venereal gonorrhoea, especially when violent. The sensation of such erections is rather uneasy than pleasant; nor is the sensation of the glans at the time similar to that arising from the erections of desire, but more like to the sensation of the parts immediately after coition. Such as arise spontaneously are of more serious consequence than those from inflammation, as they proceed, probably, from causes not curable in themselves, or by any known methods. The priapism arising from inflammation of the parts, as in a gonorrhoea, is attended with nearly the same symptoms ; but generally the sensation is that of pain, proceeding from the inflammation of the parts. It may be observed, that what is said of priapism is only applicable to it when a disease of itself, and not as a symptom of other diseases, which is frequently the case.* The common practice in the cure of this complaint is to order all the nervous and strengthening medicines, such as bark, valerian, musk, camphor, and also the cold bath. I have seen good effects from the cold bath ; but sometimes it does not agree with the constitution, in which cases 1 have found the warm bath of service. Opium appears to be a specific in many cases, from which circumstance, I should be apt, upon the whole, to try a soothing plan. Seminal weakness, or a secretion and emission of the semen without erections, is the reverse of a priapism, and is by much the worst disease of the two. There is great variety in the degrees of this disease, there being all the gradations from the exact correspondence of the actions of all the parts to the testicles acting alone; in every case of the disease there is too quick a secretion and evacuation of the semen. Like to the priapism, it does not arise from desires and abilities, although when mild it is attended with both, but not in a due proportion ; a very slight desire often producing the full effect. The secretion of the semen shall be so quick that simple thought, or even toying, shall make it flow.

* Added : " A gentleman had a priapism for two years; it originated from an irritation in the bladder, which went off at the time the priapism came: it only takes place in the night, and mostly in his sleep, and immediately awakens him ; havinf connexion makes it worse."—Home. OF IMPOTENCE. 173 Dreams have produced this evacuation repeatedly in the same night; and even when the dreams have been so slight, that there has been no consciousness of them when the sleep has been broken by the act of emission. I have known cases where the testicles have been so ready to secrete that the least friction on the glans has produced an emission: I have known the simple action of walking, or riding, produce this effect, and that repeatedly in a very short space of time. A young man, about four or five and twenty years of age, not so much given to venery as most young men, had these last-mentioned complaints upon him. Three or four times in the night he would emit; and if he walked fast, or rode on horseback, the same thing would happen. He could scarcely have connexion with a woman before he emitted, and in the emission there was hardly any spasm. He tried every supposed strengthening medicine, as also the cold bath, and sea-bathing, but with no effect. By taking twenty drops of laudanum, on going to bed, he prevented the night emissions; and by taking the same quantity in the morning, he could walk or ride without the before-mentioned inconvenience. I directed this practice to be continued for some time, although the disease did not return, that the parts might be accustomed to this healthy state of action ; and I have reason to believe the gentleman is now well. It was found necessary, as the constitution became more habituated to the opiate, to increase the dose of it. The spasms, upon the evacuation of the semen, in such cases are extremely slight, and a repetition of them soon takes place ; the first emission not preventing a second ; the constitution being all the time but little affected.* When the testicles act alone, without the accessory parts taking up the necessary and natural consequent action, it is still a more melancholy disease ; for the secretion arises from no visible or sensible cause, and does not give any visible or sensible effect, but runs off similar to involuntary stools, or urine. It has been observed that the semen is more fluid than natural in some of these cases. There is great variety in the diseased actions of these parts, ot which the following case may be considered as an example. A gentleman has had a stricture in the urethra for many years, for which he has frequently used a bougie, but of late has neglected it. He has had no connexion with women for a considerable time, being afraid of the consequences. He has often in his sleep involuntary emissions, which generally awake him at the paroxysm; but what surprises him most is, that often he has such without any semen passing through the penis, which makes him think that at

* It is to be considered that the constitution is commonly affected by the spasms only, and in proportion to their violence, independent of the secretion and evacuation of the semen. But in some cases even the erection going off without the spasms on the emission shall produce the same debility as if they had taken place. 174 HUNTER ON THE VENEREAL DISEASE.

those times it goes backwards into the bladder. This is not always the case, for at other times the semen passes forwards. At the time the semen seems to pass into the bladder he has the erection, the dream, and is awaked with the same mode of action, the same sensation, and the same pleasure, as when it passes through the urethra, whether dreaming or waking. My opinion is that the same irritation takes place in the bulb of the urethra without the semen, that takes place there when the semen enters, in consequence of all the natural preparatory steps, whereby the very same actions are excited as if it came into the passage; from which one would suppose that either semen is not secreted, or if it be, that a retrograde motion takes place in the actions of the acceleratores urinae. But if the first be the case, then we may suppose that in the natural state the actions of those muscles do not arise simply from the stimulus of the semen in the part, but from their action being a termination of a preceding one making part of a series of actions. Thus they may depend upon the friction, or the imagination of a friction on the penis, the testicles not doing their part, and the spasm in such cases arising from the friction, and not from the secretion. In many of those cases of irregularity, when the erection is not strong, it shall go off without the emission; and at other times an emission shall happen almost without an erection: but these arise not from debility, but affections of the mind. In many of the preceding cases, washing the penis, scrotum, and perinaeum with cold water is often of service; and to render it colder than we find it in some seasons of the year, common salt may be added to it, and the parts washed when the salt is almost dissolved. CHAPTER XIII.

OF THE DECAY OF THE TESTICLE.

It would appear, from some circumstances, that the parts of generation are not to be considered as necessary parts of the animal machine, but only as parts superadded for particular purposes, and therefore only necessary when those particular purposes are to be answered; for we may observe that they are later of coming to maturity than any other parts, and are more liable to decay. Thus far in their natural properties they are different from most other parts of our body, the teeth only excepted, which are similar in some of those circumstances. The testicles appear to be more subject to spontaneous disease than any other part of the body; but what is the most singular thing OF THE DECAY OF THE TESTTCLE. 175 of all is the wasting of those bodies. One or both testicles shall wholly disappear, like to the thymus gland, or membrana pupillaris, &c. in the infant. This we do not find in any parts of the body which are essential to its economy, excepting the parts are of no further use and might become hurtful in the body, as in the instance of the membrana pupillaris. But the testicles do not undergo this change as if in consequence of an original property stamped upon them, as is the case of the thymus gland, whenever the age of the person is such as to render them useless, but are liable to it at any age; and therefore the disposition is in the testicles themselves, independent of any connexion with the animal economy. An arm or leg may lose its action, and may waste in part, but never wholly. Testicles have been known to waste in cases of rupture, probably from the constant pressure of the intestine. Mr. Pott has given us cases of this kind. I have seen in the hydrocele the, testicle almost wasted to nothing, probably from ihe compression of the water; but in all these the causes of wasting are obvious, and would probably produce similar effects in other parts of the body under the same circumstances ; but a testicle without any previous disease wastes wholly ; or at other times it inflames, either spontaneously or from sympathy with the urethra, becomes large, and then begins tosubside as in the resolution of common inflammation of the body; but does not stop at the former size, but continues to decay till it wholly disappears. The following cases are instances of this. Case I. A gentleman about nine years ago had a gonorrhoea, with a bubo, which suppurated. A swelling of one of the testicles came on, for which he used the common methods of producing resolution, and seemingly with success. All the other symptoms being removed, he thought himself quite well: but some time after he found that the testicle, which had been swelled, was become rather smaller than the other, which made him now pay attention to it: this decrease continued till it wasted entirely. For some years past there has been no appearance of a testicle. He is not in the least different in inclination or powers from what he was before. . , Case II: communicated by Mr. Nanfan. " A gentleman, aged about eighteen, who never had any venereal complaint, has had two different attacks of the same nature, one in each testicle. February 3, 1776, after skating a few hours, without having to his knowledge received any injury from it, he was seized with a violent pain and inflammation of the left testicle, which in a few days increased much in size. A surgeon being sent for followed the usual treatment in such cases of inflammation. In about six weeks the inflammation and swelling gradually subsided some hardness only remaining. A mercurial plaster was now applied, which, alter being worn fo?some time, was left off. The light testicle ever since has continued gradually to decrease, and is no larger than a horsebean ; indeed the body of the testicle is quite decayed, nothing remaining but what seems part of the epididymis. It appears to 17G HUNTER ON THE VENEREAL DISEASE. have no sense of pain, except when pressed, and is very hard and uneven on its surface. The spermatic chord is not in the least affected. October 20, 1777, he was seized in the same manner in the right testicle, without any apparent cause, whereupon I was applied to. He was immediatey bled, took an opening mixture, after that a saline mixture, wTith tartar emetic ; and a fomentation and embrocation of spiritus mindereri, and spiritus vini, was used. On the 27th a cataplasm was applied of linseed meal and aqua vegeto-mineralis. This treatment was persisted in till about the middle of November. The inflammation went off, and the testicle seemed much in the natural state. On December 19 I was applied to again ; it seemed to be growing hard, and decreasing in size, much in the same manner as the other had done, which made him very unhappy. I ordered him some pills with calomel and tartar emetic, in hopes of increasing the secretion of the glands in general, and making some change in the testicle. At first this method seemed to be of service, but soon lost its effects, and the testicle began to decrease just as jthe other did." Mr. Adair and Mr. Pott were consulted with me, but nothing could be thought of that could give any hopes of success. I advised him to employ the parts in their natural uses, as much as inclination led him ; but all was to no purpose, the testicle continued to decrease till not a vestige was left. Case III: communicated by Dr. Cothom of Worcester. "A young man, aged sixteen, was suddenly seized with great coldness and shivering, attended with frequent rigors. During this paroxysm, which continued three hours, his pulse was small and contracted, and so exceedingly quick that the strokes of the artery were with difficulty counted. This period was succeeded by an intense heat, and a strong, hard, full pulse, on which account he was copiously bled; a dose of cooling physic was immediately administered, and a clyster thrown up to promote its more speedv effects. In the evening the bleeding was repeated. All this day he complained of excruciating pain in his loins and the side of his belly, descending down into the scrotum. On examining the part affected, I saw an appearance of inflammation in the groin of the left side, and a great tension about the ring of the abdominal muscles, with an enlargement of the testicles. These parts were now ordered to be fomented with a discutient fotus, strongly impregnated with crude sal ammoniac, and to be bathed with spiritus mindereri and spiritus volat. aromat., before the application of each stupe; and he was directed to take six grains of the pulv. antimonialis, with fifteen grains of nitre every three hours; his food to be thin gruel, with fruit and lemon-juice, and his drink barley-water, with sugar and nitre. Notwithstanding this antiphlogistic plan of frequent cooling physic, anodynes, three emetics, and thirteen blood-lettings, the fever continued, and the pain, inflammation, and tumour increased till the eighth day, including the first day of seizure, when seeing no hope of discussing the tumour, the testicle being nearly as large as a OF THE DECAY OF THE TESTICLE. 177 child's head, I attempted, by emollient fotuses and maturating cataplasms, to bring it to suppuration. On the 10th a fluctuation was perceptible, and on the 12th much more so, the scrotum having then put on a livid appearance. I used every possible argument for permission to open it, but he being now quite easy, would not admit it. On the 15th the patient was again attacked with rigors, coldness, and shivering, succeeded by a great feverish heat, which soon terminated in a profuse sweat; yet no pain attended this paroxysm. In the evening, however, the tumour was so prominent that 1 was of opinion it would open spontaneously before morning, when I hoped to obtain his consent to enlarge the aperture; but this not happening, and all entreaties relating to the necessity of an incision proving ineffectual, I contented myself by giving the bark with elixir of vitriol. From this time, after every paroxysm of fever, the testicle was observed to decrease. Not being permitted to make an incision, and his strength and appetite continuing good, I began to entertain hopes of success without it, and advised him to persist in the use of the tonic and antiseptic plan, with the addition of stupes wet with the decoction of bark, to be constantly applied; by which means, at the end of thirty days from the first seizure, the pus was totally absorbed. . The testicle then appeared to be of the size of a hen's egg, and was as hard as a scirrhus. I directed it to be rubbed, night and morning, with equal parts of the unguent. mercur. fort, and liniment, volat. camphorat., and ordered, internally, some mercurial alteratives, with a decoction of bark. By these aids his night sweats, and every other disagreeable symptom, gradually abated; he gathered strength, flesh, and spirits very fast, and the diseased testicle went on constantly decreasing, though very slowly, for near twelvemonths, at the expiration of which time there was no other appearance of it than a confusion of loose fibres, obvious to the feeling, in the upper part of the scrotum. About a month ago the patient consented to my examining it. Of the testicle there was not the least vestige; neither could I perceive the tunica vaginalis on that side in the groin ; but upon the os pubis, and a little under it, I could embrace with my finger and thumb the cord, and distinguish the vessels, which were without the least degree of hardness or scirrhosity; and if I pressed one in particular, I gave him exquisite pain for a moment. He is in perfect health, of a strong robust constitution, and has fine healthy children; the only change which he has perceived in the constitution has been a propensity to grow fat, which neither temperance nor violent exercise on horseback, daily, with little rest, will prevent,*

* Added : " Case IV. A gentleman had a stricture, for which he passed a bougie; inflammation and swelling came upon one of the testicles; the inflammation was removed, and the swelling subsided; the testicle continued to diminish till it was extremely small. " Case V. A gentleman had received a hurt upon one of his testicles in ridincr ; it inflamed and swelled to a very great degree ; the symptoms went off, and 16* 178 HUNTER ON THE VENEREAL DISEASE. PART IV. CHAPTER I.

I have been hitherto speaking of the effects of this poison when applied to a secreting surface, and without a cuticle; of the intention of Nature in producing these effects; and of all the consequences, both real and supposed. I now mean to explain its effects when applied to a surface that is covered with a common cuticle, as the common skin of the body, which on such a surface will be found to be very different from those I have been describing. But I may be allowed here to remark, that the penis, the common seat of a chancre, is, like every part of the body, liable to diseases of the ulcerative kind, and from some circumstances, rather more so than other parts, for if attention is not paid to cleanliness, we have often excoriations, or superficial ulcers, from that cause; also, like almost every other part that has been injured, these parts when once they have suffered from the venereal disease, are very liable to ulcerate anew. Since then this part is not exempted from the common diseases of the body, and as every disease in this part

he considered himself well; it did not, however, remain of the natural size, but gradually diminished till it entirely disappeared. "Case VI. A gentleman was lifted from the ground by the hands with a considerable jerk : he fell immediately a violent pain in the groin of the left side, and an inflammation and swelling came upon the right testicle ; when this subsided, the testicle diminished to the size of a pea, and was very hard in its 6ubstance. " Case VII. A gentleman, eighteen years of age, had a swelling brought upon one of his testicles by lying upon wet grass; it afterwards continued to diminish, till it was only one-fourth of the natural size. " Case VIII. A gentleman, twenty years of age, had been attacked at various times in the preceding eight years with violent pain and swelling in the right testicle and spermatic chord, which went entirely off, till two years ago there was a more violent seizure : for eight hours the pain was intolerable, and the swelling very great; it confined him six weeks. Since that time it has been diminishing in size and increasing in hardness : at present it is as small as a horsebean, and the spermatic chord is contracted. The left testicle has occasionally swelled, but always recovered its usual size. During the time he was affected with this pain, he has felt at intervals a pain about the neck of the bladder, especially when he made water, but not in any violent degree; he likewise frequently feels during these attacks a sensation like the circulation of some fluid within the testicles."—Home. OF CHANCRE. 179 is suspected to be venereal, great attention is to be paid in forming our judgment of ulcers here. Venereal ulcers commonly have one character, which however is not entirely peculiar to them, for many sores that have no disposition to heal (which is the case with a chancre,) have so far the same character. A chancre has commonly a thickened base, and although in some the common inflammation spreads much further, yet the specific is confined to this base. The future or consequent ulcers are commonly easily distinguished from the original, or venereal, which will be described hereafter. It is an invariable effect, that when any part of an animal is irritated to a certain degree, it inflames and forms matter, the intention of which is to remove the irritating cause. This process is easily affected when it is on a surface whose nature is to secrete, but when on a surface whose nature is not to secrete, it then becomes more difficult, for another process must be set up, which is ulceration. This is not only the case in common irritations, but also in specific irritations from morbid poisons, as the venereal disease and small-pox. The variolous matter, as well as the venerea], produces ulcers on the skin; but when it affects secreting surfaces, a diseased secretion is the consequence; and this is different in different parts; on the tongue, inside of the mouth, uvula and tonsils, the coagulable lymph is thrown out in form of sloughs, somewhat similar to the putrid sore throat; but in the fauces, and all down the oesophagus, a thickish fluid, in appearance like matter, is secreted. When the irritation is applied to a surface whose cuticle is thin, and where there is a secretion naturally, as the glans penis or inside of the prepuce, there it sometimes only irritates, so as to produce a diseased secretion, as was described ; but this is not always the effect of such irritation on such surfaces. They are often irritated to ulceration, and produce a chancre. The poison has in general either no disposition, or not sufficient powers to blister or excoriate the common skin, for if it did, the symptoms most probably would be at first nearly the same, if not exactly so, with a gonorrhoea; that is a discharge of matter from a surface, without a cuticle, newly inflamed ; for it is reasonable to suppose that the poison would produce on that excoriated surtace a secretion of matter, which would be at first a gonorrhoea, and which very probably would afterwards fall into the second mode of action or ulceration, and then become a chancre. There are three ways in which chancres are produced; first, by the poison beincr inserted into a wound; secondly, by being applied to a nonsecreting surface; and thirdly, by being applied to a common sore. To whichever of these three different surfaces it is applied, the pus produces its specific inflammation and ulceration, attended with a secretion of pus. The matter produced in consequence of those different modes of application is of the same nature with the matter applied, because the irritations are the same in both. 180 HUNTER ON THE VENEREAL DISEASE. The poison much more readily contaminates if it is applied to a fresh wound than to an ulcer, in this resembling the inoculation of the small-pox. Whether there are any parts of the skin, or any other part of the body, more susceptible of this irritation than others, in consequence of local application, is not yet ascertained. This form of the disease/like the first, or gonorrhoea, is generally caught on the parts of generation, in consequence of a connexion between the sexes ; but any part of the body may be affected by the application of venereal matter, especially if the cuticle is thin. I have seen a chancre on the prolabium, as broad as a sixpence, caught the person did not know how.* The penis, and particularly the prepuce, being the parts most commonly affected by this form of the disease, are so constructed as to suffer much from it, especially when they are very susceptible of such irritation, for the construction alone produces many inconveniences, besides considerable pain, while under the disease, and in general retards the cure. The chancre is not so frequent an effect of the poison as the gonorrhoea, and I think very good reasons may be assigned for it, although there are more modes than one of catching it, as I just now mentioned ; but the parts in two of them, to wit, the wound and the sore, are seldom in the way of being infected; therefore when it is caught, it is commonly by the same mode of application with that of the gonorrhoea ; but as the cuticle cannot be affected by this poison, this covering acting as a guard to the cutis, it is often prevented from coming in contact with it; and indeed it is almost surprising that the cutis should be affected by it where it has such a covering, excepting about the glans, the inside of the prepuce or other parts of the body, where this covering is thin. The proportion which the cases of gonorrhoea bear to those of chancre is as four or five to one. When it is caught in men it is generally upon the frasnum, glans penis, prepuce, or upon the common skin of the body of the penis, and sometimes on the forepart of the scrotum ; but I think most frequently on the frasnum, and in the angle between the penis and glans. Its affecting these parts arises from the manner in which it is caught, and not from any specific tendency in these parts to catch it more than others ; and its affecting the frasnum, &c. more frequently than the other parts of the penis arises from the external form of this part, which is irregular, and allows the venereal matter to lie undisturbed in the chinks, by which means it has time to irritate and inflame the parts, and to produce suppurative and ulcerative inflammation in them. But as this matter is easily rubbed off from prominent parts by every thing that touches them, it is a reason why such parts in general so often escape this disease. The distance of time between its application and its effects upon

* That this sore was a chancre I made no doubt, for besides its diseased appearance, he had a bubo forming in one of the glands under the lower jaw, on the same side. It is most probable that his own fingers were the conveyers. OF CHANCRE. 181 the part is uncertain; but, upon the whole, it is rather longer in appearing than the gonorrhoea; however, this depends in some measure on the nature of the parts affected. If it be the fraenum, or the termination of the prepuce into the glans, that is affected, the disease will in general appear earlier, these parts being more easily affected than either the glans, common skin of the penis, or scrotum; for in some cases, where both the glans and prepuce were contaminated from the same application of the poison, it has appeared earlier on the prepuce. I have known cases where the chancres have appeared twentyfour hours after the application of the matter, and others where it has been seven weeks. A remarkable case of this kind was in a gentleman who had not touched a woman for seven weeks, when a chancre appeared. That this was a venereal chancre was proved, by his having had the lues venerea from it, and being under a necessity of taking mercury. An officer in the army had a chancre which appeared two months after he had had any connexion with a woman. After the last connexion he marched above a hundred miles, when the chancre broke out, and only gave way to mercury. . . . This, like most other inflammations which terminate in ulcers, begins 'first with an itching in the part; if it is the glans that is inflamed, generally a small pimple appears full of matter, without much hardness or seeming inflammation, and with very little tumefaction, the glans not being so readily tumefied from inflammation as many parts are, especially the prepuce ; nor are the chancres attended with so much pain or inconvenience as those on the prepuce ; but if upon the frasnum, and more especially the prepuce, an inflammation more considerable than the former soon follows, or at least the effects of the inflammation are more extensive and visible. Those parts being composed of very loose cellular membrane, afford a ready passage for the extravasated juices ; continued sympathy also more readily takes place in them. The itching is gradually changed to pain; the surface of the prepuce is in some cases excoriated, and afterwards ulcerates: in others a small pimp e or abscess appears, as on the glans, which forms an ulcer. A thickening of the part comes on, which at first and while of the true venereal kind, is very circumscribed, not diffusing itself gradually and imperceptibly into the surrounding parts, but terminating rather abruptly. Its base is hard, and the edges a little prominent. When it begins on the frasnum, or near it, that part is very commonly wholly destroyed, or a hole is often ulcerated through it, which proves rather inconvenient in the cure, and in general it had better, in such cases, be divided at first.*

* Added • "The original excoriation or wound may heal, although contaminated and afterwards become a chancre. A gentleman in the act of copu ation ated, ana ai meDnceall round, but in two days the whole healed ; but one ^Irnke out aftorwSs into a chancre, with a hard base, which readily yielded rmercary!°ThtTs similar to what takes place in inoculation for the small-Pox.» —Home. 182 HUNTER ON THE VENEREAL DISEASE.

If the venereal poison should be applied to the skin, where the cuticle is more dense than that of the glans penis, or frasnum, such as that upon the body of the penis, or forepart of the scrotum (parts which are very much exposed to the application of this matter), then it generally appears first in a pimple, which is commonly allowed to scab, owing to its being exposed to evaporation. The scab is generally rubbed off or pushed off, and one larger than the first forms. I think there is less inflammation attending these last than those on the frasnum and prepuce, but more than those upon the glans. When the disease is allowed to go on, so as to partake of the inflammation peculiar to the habit, it becomes in many instances more diffused, and is often carried so far as to produce disagreeable symptoms, as phimosis, and sometimes paraphimosis, greatly retarding the cure; but still there is a hardness peculiar to this poison, surrounding the sores, especially those upon the prepuce. When these ulcers are forming, and after they are formed, or in the state of inflammation, it is no uncommon thing for the urethra to sympathize with them, and give a tickling pain, especially in making water; but whether or not there is ever a discharge in the urethra from such a cause I will not determine; but if a discharge never takes place but when the disease really attacks the urethra, it would make us suppose that this sympathy is not really inflammatory ; or if it is carried so far as to produce inflammation, yet that it is not of the specific kind. However, it is possible in those cases where there is a gonorrhoea preceded by a chancre, that this gonorrhoea may arise from sympathy, and is not a disease proceeding from the original contamination, nor from the matter of the chancre. That the sensation in the urethra, in those instances where there is no discharge, is from sympathy, and not from the urethra being attacked with the disease at the time that the matter laid the groundwork for the chancre, is evident from the following observation. I have seen it happen more than once, when the seat of the chancre had broke out a second time, and where no new or fresh infection had been caught, that the patient complained of the same tickling or slight pain in the urethra before any discharge had taken place in the beginning ulcerations. From the same connexion of parts I have seen a chancre coming upon the glans absolutely cure both a gleet and an irritation all along the passage of the urethra. So great was the previous irritation in this case, that I suspected a stricture; but, on passing a bougie, found none. In consequence of the urethra sympathizing with the chancre, » the testicles and scrotum will further sympathize with the urethra, and become affected. I have seen this sympathy extend over the whole pubes, and so strong, that touching the hairs gently on the pubes has given disagreeable sensations, and even pain. In speaking of the local, or immediate effects of the venereal disease, I mentioned that they were seldom wholly specific, and that they partook both of the specific and the constitutional inflamma- OF CHANCRE. 183 tion; and therefore it is always very necessary to pay some attention to the manner in which chancres first appear, and also to their progress, for they often explain the nature of the constitution at the time. If the inflammation spreads fast, and considerably, it shows a constitution more disposed to inflammation than natural. If the pain is great, it shows a strong disposition to irritation. It also sometimes happens that they begin very early to form sloughs; when this is the case, they have a strong tendency to mortification. These additional symptoms mark the constitution and direct the future mode of treatment. When there is a considerable loss of substance, either from sloughing or ulceration, a profuse bleeding is no uncommon circumstance, more especially if the ulcer is on the glans; for it would appear that the adhesive inflammation does not sufficiently take place there to unite the veins of the glans so as to prevent their cavity from being exposed, and the blood is allowed to escape from what is called the corpus spongiosum urethras. The ulcers or sloughs often go as deep as the corpus cavernosum penis, where the same thing happens.*

* [In this chapter the author has delineated with his usual sagacity and precision the true characters of a primary venereal sore. At least his description applies to a large majority of such cases. It is the more valuable as the points of distinction are not drawn merely from obvious appearances, which, though they strike the eye, are scarcely communicable by language, but from the laws which govern the effects of the venereal virus, and the operation of which may be traced even where the appearances are dissimilar. Two consequences follow the application of the venereal virus, induration and ulceration. These two consequences seem to be distinct and independent; since, though they generally exist in conjunction, they are sometimes found separate, one or the other of them being in some cases wanting. The induration, though not always so obvious as the ulceration, is on the whole more constant, more characteristic, more peculiar and distinct in its appearance. The author has therefore rightly directed the attention more especially to the thickening as a distinction of a primary venereal sore. The description given of this peculiar thickening by the author can scarcely be improved. It is " very circumscribed, not diffusing itself gradually and imperceptibly into the surrounding parts, but terminating rather abruptly." It retains these characters through all its stages, though they may be sometimes partially obscured by other concomitant circumstances. The thickening in general precedes the ulceration. The first effect of venereal contamination is°to produce this peculiar change in the texture of the part; the second effect is to produce ulceration of the indurated portion. The character of primary venereal infection is essentially induration passing afterwards into ulceration. In the earliest stage of the existence of a chancre this sequence is least discernible, there being frequently at that period superficial and incipient ulceration with very little apparent thickening. But in the progress of the disorder the two stages become in general very clearly distinguishable. If the sore be watched, it°will be found that the thickening becomes daily more distinct and extensive, till the ulcer assumes the true venereal appearance of a sore situated on an indurated base. The induration everywhere encompasses the ulcer, being both beneath it and around it, forming as it were the bed of the sore, and at the same time encircling its margin, so as to connect it everywhere with the sound parts in the vicinity. In fact it marks the part most recently contaminated, which has not yet passed into ulceration. In the progress of the case, the induration 1S4 HUNTER ON THE VENEREAL DISEASE. § 1. Of the Phimosis and Paraphimosis.

These diseases arise from a thickening of the cellular membrane of the prepuce, in consequence of an irritation capable of producing

spreads first, so that no parts are involved in the ulcer until they have previously passed through this change of texture. A primary venereal sore is scarcely ever stationary. The ulcer itself may be stationary; but careful observation will detect a gradual increase of the thickened base, which proves, no less certainly than the enlargement of the ulceration itself, that the virus is steadily extending. These observations will explain certain occasional variations in the aspect of venereal sores, which, though sufficiently intelligible when closely examined, are exceedingly perplexing to those who form their diagnosis merely from the obvious appearances. It is not very uncommon that a primary venereal sore should assume the following characters. A portion of the prepuce, of about the size of a silver penny, shall become slightly thickened so as to lose its natural flexibility; and perhapa the surface shall be slightly excoriated. In the course of a few days, if the part is kept very clean, the excoriation shall in many cases disappear, but the hardness shall progressively increase, assuming a more defined character, and at last forming a large flat mass of the size of half-a-crown, so inflexible and rigid that the prepuce cannot be everted without difficulty. There shall be no tenderness, no inflammation, sometimes no ulceration at all, at other times only a slight dark-coloured excoriation of the surface. Yet the case shall be venereal. If the usual anti-venereal remedies are not employed, all doubts on this subject shall be removed at the end of eight or ten weeks by the appearance of distinct secondary symptoms. In this case the aspect of the part bears no obvious resemblance to that of a common chancre ; yet the difference is more apparent than real. The venereal virus produces the usual induration; but, from the slowness of its progress and the absence of inflammation, the indurated portion does not pass into ulceration. With this single exception, the course of the disease is the same as that of an ordinary chancre. The increase of the hardness is progressive, until mercury is employed. As soon as the constitution is affected by the remedy, the thickened mass begins to diminish in size, and it gradually disappears from the circumference to the centre, exactly like the induration left by a chancre. As a still further proof of the identity of the diseases, it may be stated, that, notwithstanding the absence of ulceration, the contiguous surface is often similarly affected. A similar induration will be produced in the part of the glans with which the original tumour is in contact, or on the opposite nympha when this affection is situated on the nympha in the female. Again, the deviation from the usual course may be of an opposite kind. The ulceration may be so rapid as to overtake the induration, and to destroy it as quickly as it is formed. Sores are frequently seen, especially on the external prepuce, which spread rapidly, sometimes by sloughing and sometimes by ulceration, with profuse discharge and some surrounding inflammation, but with little or no characteristic hardness. But the absence of this distinctive character of venereal sores is only accidental, and is occasioned by the rapid progress of the ulcer: for if the extension of the sore be checked by local means, which may often be effected, the surrounding induration shall appear, and shall become daily more palpable; until its further progress is stopped by such remedies as act directly on the virus, and thus remove the cause from which it arises. It is evident that these occasional variations do not affect the truth of the general position, that the natural result of venereal infection is induration passing into ulceration. But in the practical application of this principle as a criterion of the real nature or a sore, some circumstances must be taken into the account, which often modify the appearances and perplex the diagnosis. The true venereal induration is "circumscribed, and terminates abruptly." But when much inflammation is present these characters will not be discernible. OF CHANCRE. 185 considerable and diffused inflammation, which, when it does happen, is generally in consequence of a chancre in this part. This irritation, however, and inflammation sometimes attacks the prepuce, even when the disease is in the form of what I suspect to be a gonorrhoea of the glans and prepuce,* sometimes even in the common

The specific thickening will be confounded in the general thickening from inflammation, and will not be distinguishable from that which may attend an ordinary sore. Its existence cannot be distinctly and indubitably ascertained till the general inflammation is removed or palliated ; and then, when the surrounding lymph is absorbed, there will still remain at the seat of the sore a hardened base and a hardened circumference, having a well-defined abrupt margin. Sores that are ill-conditioned may produce surrounding thickening, although free from all specific virus. If the surface is sloughy, the base may be indurated. In such cases it is sometimes impossible to say at once with certainty whether the thickening is to be ascribed to the presence of the venereal virus, or is the mere consequence of the ill-conditioned stale of the sore. The opinion should generally be suspended, and local means should be used for the removal of the slough. When this is effected, in common sores, the hardness which was produced by the irritation will disappear also: in venereal sores, notwithstanding a similar change of the surface has been produced, the induration will nevertheless remain, and continue to spread, and ultimately the sore will again become foul and perhaps sloughy. It is evident therefore that the distinction is to be drawn less from the appearance of the sore at any one moment than from its course and progress. Many circumstances may at any one time confuse the appearance, and may deceive the surgeon ; but it is scarcely possible that he can err, if he watches the progress of the case, and uses means to obviate the causes of error. If the sore be venereal, he will be able to detect the changes which mark the contamination, viz. first, induration ; and secondly, ulceration. It is not meant that the other characters of venereal sores are to be disregarded in forming the diagnosis. The bright red areola which encircles them ; the mode of extension which is equally in all directions; the disposition of the discharge from them to produce similar sores on the surfaces with which it is allowed to come in contact; these all form important distinctions, and should by no means be overlooked. But it often happens that these tests cannot be applied. The red areola is often obscured by surrounding inflammation, and altogether undistinguishable. Sores which are not venereal often spread regularly and evenly from a centre. Where attention is paid to cleanliness and the discharge is not allowed to collect, no other sores will be produced, and the original chancre will remain single. The character and course of the induration form on the whole that criterion which is most certain and most generally observable. But it must not be forgotten that there is a class of venereal sores to which the above description does not apply. In the sores usually called phagedenic, the progress of the ulcer is not preceded by the venereal induration, nor is such induration left after it is cicatrized. The other points of discrimination fail also. The extension is irregular, one edge generally spreading while another is healing : and the discharge does not infect the parts on which it is suffered to rest. Yet undoubtedly these sores are the consequence of impure connexion, and are followed by secondary symptoms; and it is therefore difficult to deny their venereal origin, though the laws which they observe are very different from those which regulate the course of a common chancre. They are comparatively rare. The description of the author is applicable to forty-nine cases out of fifty ; and its practical value is scarcely diminished by the occasional occurrence of phagedenic sores, which may be readily known by the characters which peculiarly below* to them, and of which a more particular description will be given hereafter.]™ . . . * See page 49, where this gonorrhoea is mentioned. 186 HUNTER ON THE VENEREAL DISEASE. gonorrhoea, but most frequently of all from a chancre in the prepuce. When this disease or tumefaction takes place in consequence of a chancre, I suspect that there is an irritable disposition in the habit; for it is plain there is more than the specific action, the inflammation extending beyond the specific distance.* It may be observed here, that the prepuce is no more than a doubling of the skin of the penis when not erected, for then it becomes too large for the penis, by which provision the glans is covered and preserved when not necessary to be used, whereby its feelings are probably more acute. When the penis becomes erect it in general fills the whole skin, by which the doubling forming the prepuce in the non-erect state is unfolded, and is employed in covering the body of the penis. The diseases called phimosis and paraphimosis, being a thickening of the cellular membrane of this part, they will commonly be in proportion to the inflammation and distensibility of the cellular membrane of the part. The inflammation often runs high, and is frequently of the erysipelatous kind ; besides, in such parts where the cellular membrane is so very loose, the tumefaction is considerable, and the end of the prepuce being a depending part, the serum is accumulated in it, which in many inflammations is allowed to pass from the inflamed to some more depending part, as in an inflammation of the leg or thigh, where the foot commonly swells or becomes cedematous in consequence of the descent of the serum extravasated above. A natural contraction of the aperture of the prepuce is very common, and so strong in some that those under such construction of parts have a natural and constant phimosis. Such a state of parts is often attended with chancres, producing very great inconveniences in the time of the cure; and in those cases of considerable diffused inflammation, a diseased phimosis, similar to the other, unavoidably follows ; and, whether diseased or natural, it may produce the paraphimosis simply by the prepuce being brought back upon the penis ; for this tight part acting as a ligature round the body of the penis, behind the glans, retards the circulation beyond the ligature, producing an cedematous inflammation on the inverted part of the prepuce. When the paraphimosis takes place in consequence of a natural tightness only, although attended with chancres, yet it has nothing to do with the constitution, this being only accidental ; however, in either case a paraphimosis is to be considered as in some degree a local violence. This natural phimosis is so considerable in some children as not to allow the urine to pass with ease ; but in general becomes larger and larger as boys grow up, by frequent endeavours to bring it over

* [Any ulcer on the internal prepuce may produce phimosis, because it may be attended by so much thickening as to destroy the natural flexibility of the prepuce. A chancre is more likely to produce it than any other sore, because it is necessarily accompanied by induration, and that of a kind which is much more obstinate than the thickening of a common inflammation.] OF CHANCRE. 187 the glans, by which the bad consequences that would otherwise ensue in it when affected with disease are often prevented. This part of the prepuce, although in most men it is loose enough to produce no inconvenience in a natural state, yet it sometimes contracts without any visible cause whatever, and becomes so narrow as to hinder the water from getting out, even after it has got free from the urethra, so that the whole cavity of the prepuce shall be filled with the urine, and give great pain. The cases that I have seen of this kind have been principally in old men. When the prepuce is in its natural position it then covers entirely the glans, and is commonly a little loose before it; but when it begins to swell and thicken, more and more of the skin of the penis is drawn forwards over the glans, and the glans at the same time is pushed backwards by the swelling against its end. I have seen the prepuce projecting from such a cause more than three inches beyond the glans, and its aperture much diminished. The prepuce often becomes in some degree inverted by the inner skin yielding more than the outer, having a kind of neck where the outer skin naturally terminates. From the tightness and distension of the parts in a state of tumefaction it becomes impossible to bring it back over the penis, so as to invert it and expose the sores on the

Such a state of the prepuce is very often productive of bad consequences, especially when the chancres are behind the glans; for the glans beino- between the orifice of the prepuce and the sores, it there fills up the whole cavity of the prepuce, between the chancres and opening, and often so tightly, that the matter from the sores behind cannot get a passage forwards between the glans and prepuce, by which means there is an accumulation of matter behind the corona glandis, forming an abscess which produces ulceration upon the inside of the prepuce. This abscess opens externally, and the glans often protruding through the opening, throws the whole prepuce to the opposite side, the penis appearing to have two terminations. , .. , . . , „ On the other hand, if the prepuce is loose, wide, and is either accustomed to be kept back in its sound state or is pulled back to dress the chancres, and is allowed to remain in this situation till the above tumefaction takes place,then it is called a paraphimosis; or if the prepuce is pulled forcibly back after it is swelled it is then brought from the state of a phimosis, as before described, to that of a paraphimosis. . , _^„Q This last-described situation of the prepuce is often much more troublesome, and often attended with worse symptoms, than the former, especially if it should have been changed from a phimosis oTparaphimosis. The reason of which is, that the aperture of he prepuce is naturally less elastic than either the internal inverted nart or the external skin ; therefore when the prepuce is pulled back won the body of the penis, that part grasps it tighter than any other pari of the skin of the penis, and more so in proportion to the in- 188 HUNTER ON THE VENEREAL DISEASE. flammation: the consequence of which is, the swelling of the prepuce is divided into two, one swelling close to the glans, the other behind the stricture or neck. This stricture is often so great as to interrupt the free circulation of the blood beyond it, which also assists in increasing the swelling, adds to the stricture, and often produces a mortification of the prepuce, itself, by which means the whole diseased part, together with the stricture, is sometimes removed, forming what may be called a natural cure.* In many cases the inflammation not only affects the skin of the penis, in which is included the prepuce, but it attacks the body of the penis itself, often producing adhesions and even mortification in the cells of the corpora cavernosa, either of which will destroy the distensibility of those parts ever after, giving the penis a curve to one side in its erections. This sometimes takes place through the whole cellular substance of the penis, producing a short and almost inflexible stump. The adhesions of those cells do not proceed from venereal inflammation only; they are often the consequences of other diseases, and sometimes they take place without any visible cause whatever. A gentleman, sixty years of age, who has been lame with the gout these twenty years past, has for these eighteen months had the penis contracted on the left and upper side, so as to bend that way very considerably in erections, which erections are more frequent than common. Quere: Is the gout the cause of this by producing adhesions of the cells of one corpus cavernosum, so as not to yield or to allow of the influx of blood on that side ? And is the irritation of the gout the cause of the frequency of the erections ? CHAPTER II.

Women are subject to chancres; but from the simplicity of the parts, the complaint is often less complicated than in men. For in this sex we have only the disease and constitutional affection, and no inconvenience arising from the formation of the parts. When the matter is introduced into the vagina or urethra it there irritates a secreting surface, as I described when treating of the

* A young man came into St. George's Hospital with a paraphimosis in consequence of chancres on the inside of the prepuce. All the parts before the stricture, formed by the prepuce, mortified and dropped off. I ordered nothing but common dressings, and it healed very readily, and he left the hospital cured of the local complaint. Whether or not absorption had taken place previous to the mortification I do not know, as I never heard more of him. ON THE TREATMENT OF CHANCRE. 189 disease in general and of women in particular; but when it is lodged in the inside of the skin of the labia or nymphae, those parts are often only affected with gonorrhoea ; but, like the glans penis in men, they are also capable of ulceration. Ulcerations are generally more numerous in women, because the surface upon which they can form is much larger: we find them on the edge of the labia, sometimes on the outside, and even on the perinaeum. Ulcers that are formed on the inside of the labia or nymphae are never allowed to dry or scab; but on the outside they are subject to have the matter dry upon them, which forms a scab similar to those on the body of the penis or scrotum. The venereal matter from such sores is very apt to run down the perinasurn to the anus, as in gonorrhoea, and excoriate the parts, especially about the anus where the skin is thin, and often produces chancres in those parts. Chancres have been observed in the vagina; which I suspect not to have been original ones, but to have arisen from the spreading of the ulcers on the inside of the labia.* This form of the disease, like the gonorrhoea, both in women and in men, is entirely local, the constitution having no connexion with it but sympathetically, and I believe much more seldom in this than in the former. CHAPTER III.

general observations on the treatment of chancres.

The inflammation from the venereal poison, when it produces ulceration, generally if not always continues till cured by art, which I observed was not the case with the gonorrhoea. It will perhaps not be an easy task to account for the material difference in the two kinds of disease; but I am inclined to think that as the inflammation in the chancre spreads it is always attacking new ground, which is a succession of irritations, and is the cause that it does not cure itself. Chancres, as well as the gonorrhoea, are perhaps seldom or never wholly venereal, but are varied by certain peculiarities of the constitution at the time. The treatment therefore of them, both local and constitutional, will admit of great variety ; and it is upon the knowledge of this variety that the skill of the surgeon principally

* [Original chancres do occasionally occur within the vagina, being situated either on the membrane lining the vagina or on the os uteri itself. These chancres can only be delected by the use of a speculum. However, sores on these internal parts are extremely rare, notwithstanding the degree in which they are exposed to the contact of the venereal virus during coition.] V 17* 190 HUNTER ON THE VENEREAL DISEASE. depends. On this account the concomitant symptoms are what require particular attention. Mercury is the cure of the venereal symptoms abstractedly considered ; but there is no one specific for the others, the treatment of which must vary according to the constitution. From hence we must see that no one kind of medicine joined with mercury will be likely to succeed in all cases, although the different pretended secrets are of this kind, some cases not requiring anything excepting mercury, others requiring a something besides, according to their nature, which in many cases it will not be an easy matter to find out from the appearances of the chancre itself, but which must be discovered by repeated trials. Probably from the before-mentioned circumstances it is, that a chancre is in common longer in healing than most of the local effects from the constitutional disease, or lues venerea, at least longer than those in the first order of parts; and this is found to be the case notwithstanding that the cure of a chancre may be attempted both constitutionally and locally, while the lues venerea can in common only be cured constitutionally. It is commonly some time before a chancre appears to be affected by the medicine. The circulation shall be loaded with mercury for three, four, or more weeks before a chancre shall begin to separate its discharge from its surface, so as to look red and show the living surface, but when once it does change, its progress towards healing is more rapid. A lues venerea shall in many cases be perfectly cured before chancres have made the least change. Upon the same principle some attention should be paid to internal medicines, and it should be considered whether weakening, strengthening, or quieting medicines should be given; for sometimes one kind, sometimes another, will be proper. Chancres admit of two modes of treatment: the object of one is to destroy or remove them by means of escharotics or by extirpation, that of the other is to overcome the venereal irritation by means of the specific remedy for that poison. I have endeavoured to show that chancres are local complaints: this opinion is further confirmed by their being destroyed or cured by merely a local treatment. But in chancre, as well as in a gonorrhoea, it has been disputed whether mercury should ever be applied locally to them or not; some have objected to it, while others have practised it, and probably the dispute is not yet generally settled. Upon the general idea which I have endeavoured to give of the venereal disease it can be no difficult task to determine this question. It is to be observed that in the cure of the chancres we have two points in view : the cure of the chancre itself and the prevention of a contamination of the habit. The first, or the cure of the chancre, is to be effected by mercury applied either in external dressings, or internally through the circulation, or in both ways. The second object, or preservation of the ON THE TREATMENT OF CHANCRE. 191 constitution from contamination, is to be obtained, first, by shortening the duration of the chancre, which shortens the time of absorption, and also by internal medicine, which must be in proportion to the time that the absoption may have been going on. If the power of a chancre to contaminate the constitution, or, which is the same thing, if the quantity absorbed is as the size of the chancre and the time of absorption, which most probably it is, then whatever shortens the time must diminish that power or quantity absorbed ; and if the quantity of mercury necessary to preserve the constitution is as the quantity of poison absorbed, then whatever lessens the quantity absorbed must proportionally preserve the constitution. For instance, if the power of a chancre to contaminate the constitution in four weeks is equal to four, and the quantity of mercury necessary to be given internally, both for the cure of the chancre and the preservation of the constitution's also equal to four, then whatever shortens the duration of the chancre must lessen in the same proportion the quantity of the mercury; therefore, if local applications along with the internal use of mercury will cure the chancre in three weeks, then only three-fourths of the mercury is necessarily wanted internally. Local applications, therefore, so far as they lend to shorten the duration of a chancre, shorten the duration of absorption, which also shortens the necessity of the continuance of an internal course of mercury, all in the same proportion. For example: if four ounces of mercurial ointment will cure a chancre and preserve the constitution in four weeks, three ounces will be sufficient to preserve the constitution if the cure of the chancre can be by any other means forwarded so as to be effected in three weeks. This is not speculation, but the result of experience, and the destruction of chancres confirms it.*

§ 1. Of the Destruction of a Chancre.

The simplest method of treating a chancre is by destroying or extirpating it, whereby it is reduced to the state of a common sore or wound, and heals up as such. This only can be done on the first appearance of the chancre, when the surrounding parts are not as yet contaminated, because it is absolutely necessary that the whole diseased part should be removed, which is done with difficulty when it has spread considerably. It may be done either by incision or by caustic. If the chancre appears upon the glans, touching it with the lunar caustic is preferable to incision, because

* [The author's experience on this point seems to be at variance with that of others. It does not appear that in practice it is safe to make the period of the healing cf the sore a measure of the length of the mercurial course. General experience would seem to show that a mercurial course for primary symptoms, even though it be commenced before the chancre has existed a week, cannot be continued'for a less period than a month, without exposing the patient to imminent danger of a subsequent relapse.] 192 HUNTER ON THE VENEREAL DISEASE. the hemorrhage by such a mode would be considerable from the cells of the glans. The common sensation of the glans is not very acute, therefore the caustic will give but little pain. The caustic to be used should be pointed at the end like a pencil, that it may only touch those parts that are really diseased. This treatment should be continued till the surface of the sore looks red and healthy, after having thrown off the last sloughs; after it has arrived at this state, it will be found to heal like any other sore produced by a caustic. If the sore is upon the prepuce, or upon the common skin of the penis, and in its incipient state, the same practice may be followed with success; but if it has spread considerably, it.is then out of the power of the caustic, when only applied in this slow manner, to go so deep as to keep pace with the increasing sore, but it is very probable that the lapis septicus may answer very well in such cases. When this cannot be conveniently used, incision will answer the purpose effectually. I have taken out a chancre by dissection, and the sore has healed up with common dressings. However, as our knowledge of the extent of the disease is not always certain, and as this uncertainty increases as the size of the chancre, it becomes necessary in some degree to assist the cure by proper dressings, and therefore it may be prudent to dress the sore with mercurial ointment. From such treatment there is but little danger of the constitution being infected, especially if the chancre has been destroyed almost immediately upon its appearance, as we may then reasonably suppose there has not been lime for absorption. But, as it must be in most cases uncertain whether there has been absorption or not, this practice is not always to be trusted to, and from that circumstance perhaps never should; and therefore, even in those cases where the chancre has been removed almost immediately, it would be prudent to give some medicine internally, the quantity of which should be proportioned to the time and progress of the sore; but if it has spread to a considerable size before extirpation, then mercury is absolutely necessary, and perhaps not a great deal is gained by the extirpation.*

* [The treatment of chancres by caustic or extirpation is more beautiful in theory than commendable in practice. It is impossible to know with certainty to what distance the virus has extended, and the whole of the contaminated parts may not therefore be destroyed by the caustic. This defect is not always evident a the time The sore may cicatrize under the caustic, yet the virus^may not be extirpated, and the general system may be subsequently affected. AoSn^angtiJ seems to increase the d.sposmon to absorption, so that if the object isCt attained by the first application n will not in general be achieved by its repent ion Hence U happens ,n very many instances, that the use of caustic is followed immediately by a bubo and at a more remote period by secondary symptoms^ Z patient who might have been cured ,n the first instance by a moderate course of me^urv'

be employed witLut considerate"risf T^ZiTS^ ^LZTy ON THE TREATMENT OF CHANCRE. 193 § 2. Of the Cure of Chancres.—Local Application.

The cure of a chancre is a different thing from its destruction, and consists in destroying its venereal disposition, which being effected, the parts heal of course as far as they are venereal. Chancres may be cured in two different ways, either by external applications, or internal through the circulation. The same medicine is necessary for both these purposes, that is mercury. I have shown that a gonorrhoea and a chancre have so far the same disposition as to form the same kind of matter, yet I have also observed that mercury has no more power in curing the gonorrhoea than any other medicine, and therefore it might be supposed that mercury would have no effect in the present complaint; but we find that in a chancre it is a specific, and will cure every one that is truly venereal: but as other dispositions take place so other assistance is often necessary, as will be taken notice of in the history of the cure. The action of this medicine must be the same in whatever way it is given, for its action must be upon the vessels of the part, in one way acting only externally, in the other internally.* , For external local applications mercurial ointments are the common dressings; but if the mercury were joined with watery substances instead of oily, by mixing with the matter, the application would be continued longer to the sore, and would prove more effectual. This is an advantage that poultices have over common dressings. I have often used mercury rubbed down with some conserve in the room of an ointment, and it has answered extremely well. Calomel used in the same way, and also the other preparations of mercury mixed with mucilage or with honey, answer the same purpose. Such dressings will effect a cure in cases that are truly venereal; but perhaps we seldom have a constitution quite free from some morbid tendency. - Some will have an indolent disposition, to counteract which it will be right to join with the mercury some warm balsam in a small proportion, or as much red precipitate as will only stimulate, without acting as an escharotic ; and sometimes both may be necessary. Calomel mixed with some salve, or any other substance which

caustic should therefore be reserved for those cases where, from peculiar circumstances, an immediate course of treatment must be avoided at all risks. When caustic is supposed to be successful the sores are for the most part not chancres, but simple pustules or herpetic vesicles.] 11 «„„,«, * This is well illustrated by the application of some medicines locally to parts whose actions are immediate and visible; and by throwing the same medicine into the constitution the same immediate and visible effect is produced: for instance if ten grains of ipecacuanha is thrown into the stomach of a dog, it will in a short time make him vomit, from its local applications to that viscus ; and if a solution of five grains is thrown into a vein it will produce vomiting before wp Mn conceive it to have got to the vessels of the stomach. The same effects Ire produced from an infusion of jalap thrown into the veins that are commonly produced when taken into the stomach and bowels. 194 HUNTER ON THE VENEREAL DISEASE. will suspend it, is more active than common mercurial ointment, and in such cases as require stimulating applications it will answer better. Many other applications are recommended, such as solutions of blue vitriol, verdigris, calomel, with the spiritus nitri dulcis, and many others. But as all of these are only of service in remedying any peculiar disposition of the parts, having no specific power on the venereal poison, and as such dispositions are innumerable, it becomes almost impossible to say what will be effectual in every disposition: some will answer in one state of the sores, some in another. It may be found oftentimes that the parts effected are extremely irritable: in such cases it will be necessary to mix the mercury with opium, or perhaps preparations of lead, as white or red lead, to diminish the action of the parts. The oftener the dressings are shifted the better, as the matter from the sore separates the application from the diseased parts, by which means the effects are lost or diminished. Three times every day in many cases is not oftener than necessary, especially if the dressings are of the unctuous kind ; for they do not mix, like watery dressings, with the matter, so as to impart some of their virtues to it, which would in a proportional degree affect the sore. Chancres, after having their venereal taint corrected, often become stationary, and having acquired new dispositions, increase the quantity of disease in the part, as will be taken notice of hereafter. When they become stationary only they may often be cured by touching them slightly with the lunar caustic. They seem to require that the surface which has been contaminated, or the new flesh which grows upon that surface, should be either destroyed or altered before it can cicatrise; and it is surprising often how quickly they will heal after being touched, and probably once or twice may be sufficient. J

§ 3. Of the Treatment of Phimosis in consequence of or attended with Chancre.

From the history which I have given of the disease we must see that a phimosis may be of two kinds: one natural, with the disease superadded, the other brought on by disease. The first may be increased by the disease ; but if otherwise, it is not so troublesome as the other. Such as arise from the disease, I have observed, depend upon the peculiarity of the constitution. In either case it is often not practicable to apply dressings to the chancres on the inside of the prepuce. A phimosis should be prevented, if possible; therefore, upon the least signs of a thickening of the prepuce, which is known by its ouief -lffn ll Wlth dl^Ynd Pain' the Pat^ should be kept 2ni «f L so much the better, as in a horizontal position the end of the penis will not be so depending, but may be kept up. If ON THE TREATMENT OF CHANCRE. 195 confinement in bed cannot be complied with, then the end of the penis should be kept up to the belly, if possible; but this can hardly be done when the person is obliged to walk about, for the extravasated fluids, descending and remaining in the prepuce, contribute often more to render the prepuce incapable of being drawn back than the inflammation itself. When the diseased phimosis completely takes place the same precautions may be followed; but as the sores cannot be dressed in the common way, we must have recourse either to dressings in forms of injections', or the operation for the phimosis. If we use injections only, they should be often repeated, as they are only temporary applications. . The dressings, in form of injections, should be mercurial, either crude mercury rubbed down with a thick solution of gum arabic, which will assist in retaining some of the injection between the glans and prepuce; or calomel with the same, and a proportion of opium. In the proportion of these no nicety is required; but if a solution of corrosive sublimate is made use of as an injection some attention is to be paid to its strength. About one grain of this to an ounce of water will be as much as the sensation of the part will allow the patient to bear, and if this gives too much pain it may be lowered by adding more water. , , • • • • After the parts are as well cleaned as possible with this injection, it will be necessary to introduce other mercurial applications of some kind, to remain there till the parts want cleaning again, which will be verv soon. Such as are mentioned before will answer this purpose veVy well; but I have my doubts about the propriety of using any irritating medicines or injections in such cases. As often as he voids his urine the patient may wash the parts, by pressino- the orifice of the prepuce together, so as to oblige the w-ater to i?un back between the prepuce and glans ; immediately after this the patient should use the mercurial applications, otherwise this operation of washing may do harm, as it will wash away the former application of mercury; but in many cases the parts are so sore as not to allow of this practice. A poultice of linseed meal alone, or of equal parts of this and bread, should be applied. This poultice is to be made with water, to which one eighth of laudanum has been added. But previous to this, and immediately after the cleaning, it would be very proper to let the penis hang over the steam of hot water, with a little vinegar and spirits of wine in it, which is the neatest way of applying

^heofiener this is practised the better, for thus a mercurial application is kept in contact with the diseased parts a greater number of the hours out of the twenty-four, than otherwise could be were the matter allowed to lie on the parts. When to the above-mentioned symptoms a bleeding of the chancre is added I do not know a more troublesome complaint, because 19G HUNTER ON THE VENEREAL DISEASE. here the cells or veins have no great disposition for contraction.5* Oil of turpentine gives the best stimulus for the contraction of vessels of all kinds ; but where bleeding arises from an irritable action of the vessels, which is sometimes the case, then sedatives are the best applications. Whatever is used in such a state of the prepuce must be injected into the part. When in consequence of the treatment the inflammation begins to go off, and the chancres to heal, it will be necessary to move the prepuce upon the glans as much as they will allow of, to prevent adhesions, which sometimes happen when there have been chancres on both surfaces opposite to each other. Indeed the practice here recommended is such as will in general prevent such consequences. If this has not been properly attended to, and the parts have grown together, the consequences may not be bad ; but it must be very disagreeable to the patient, and a reflection upon the surgeon. Ihave seen the opening into the prepuce so much contracted from all these internal ulcers healing and uniting, that there was hardly any passage for the water. If the passage in the prepuce so contracted be in a direct line with the orifice of the urethra, then a bougie may be readily passed; but this is not always 4he case: it often happens that they are not in a direct line, therefore an operation becomes necessary. The operation consists in either slitting up part of the prepuce, or removing part of it; but as these parts have become very indistinct from the adhesions, either the slitting it up, or removing part of it, becomes a difficult operation. Whenever the urethra is discovered, or can be found out by a bougie, that is to be introduced, and its application repeated till the passage becomes free, and has got into the habit of keeping so. I observed formerly that this tumefaction sometimes produced a confinement of the matter formed by the chancre, and that while this effect lasted no subsiding of the inflammation or tumefaction could take place; that therefore those diseases continued to exist, and that the part thus circumstanced came under our definition of an abscess; that is, the formation of matter in a state of confinement. Although it never has been considered in this light, yet the necessary treatment shows it to be such. This consists in laying it open from the external orifice to the bottom where the matter lies, as in a sinus, so as to discharge it. However, the intention annexed to this practice was not to allow of the discharge of the matter of the sore, but to admit of the applications of dressings to it, for it has been recommended and practised where there was no particular confinement of matter, which I have not found to be necessary merely for that purpose, as we are in possession of an internal remedy; and if the opening produces no other good but the

* I suspect that where chancres bleed profusely, the blood comes either from the glans, when thpre are chancres there, or from the spongy substance of the urethra, where ihe chancre has begun about the fraenum, for we seldom see profuse bleeding" from ihe prepuce when its inside is the seat of the chancre, and can be exposed ; but indeed in such cases the inflammation is not violent. ON THE TREATMENT OF CHANCRE. 197 allowing of the application of dressings, it is not so material, because the sores may be washed with an injection through a syringe.

§ 4. Of the common Operation for the Phimosis produced by Chancres. The common operation for the phimosis is slitting the prepuce nearly its whole length, in the direction of the penis; but even this is sometimes thought not sufficient, and it is directed to cut the prepuce in two different places, nearly opposite to one another. When it was thought proper to be done in this way, it was imagined that it was seldom necessary to cut the whole length of the prepuce. It will in some degree depend on circumstances which practice is to be followed. If it is a natural phimosis without tumefaction, and the chancre is near the orifice of the prepuce, which in such cases it most probably will be, as the glans is not denuded in coition so as to have chancres deeper seated, then it may be necessary only to go as far as the chancres extend. From the common situation of the chancre, this disease of the phimosis arises more commonly from the tumefaction of the parts; and from the idea I have endeavoured to give of the inconveniences arising from this phimosis, where the chancres are placed behind the corona, producing a confinement of the matter behind the glans, slitting open the prepuce a little way cannot be sufficient, for in such cases it must be exposed to the bottom, or no good can arise from the operation. Although this operation will not take off the tumefaction of the prepuce, so as to allow it to be brought back, yet it will allow of a free discharge of the matter, and also in some cases it will allow of dressings being applied to the sores, but not m all, for the tumefaction will not allow more of an inversion of the prepuce than before, and in such the sores cannot have dressings applied to them. , . , ... In many cases it will be found that so violent an operation is improper, for it often happens that, while the inflammation is so very considerable, there is danger of increasing it by this additional violence, of which mortification may be the consequence ; while on the other hand there are cases where a freedom given to the parts would prevent mortification, so that the surgeon must be guided by the appearances and other circumstances. Besides these reasons for and against the operation arising from the disease itself, it will not always be consented to by the patients themselves for some have such a dread of operations that they wil not submit to cutting instruments ; however in those cases where the matter is confined it will be absolutely necessary to have an opening somewhere for the discharge of it. This is often produced by the ulcerative process going on on the inside, which makes an opening directly through ?he skin laterally, which affords a direction for the surgeon : therefore the^openTng may be made directly into the cavity of the prepuce, 18 198 HUNTER ON THE VENEREAL DISEASE. through the skin, on the side of the penis, by a lancet: or a small caustic may be applied there, for which the lapis septicus is the most convenient. The opening will allow of the discharge of the matter, and also admit any proper wash to be throw in. But this opening should not be a large one, as in many cases the consequence of this lateral opening proves very troublesome; for from the tumefaction of the prepuce the glans is squeezed on all sides, and rather more backwards upon the body of the penis than in any other direction, by which means it is often forced through this opening, whereby the glans is directed to one side, and the prepuce to the opposite, having a forked appearance. Besides this state of the parts tightens the skin of the penis round the root of the glans, acting there somewhat like a paraphimosis, and sometimes makes the whole prepuce mortify and drop off, which is often a lucky circumstance ; but if this is not the consequence, then amputation of the prepuce becomes necessary: however, this should not be done till all inflammation is gone off, and the chancres are cured, when probably the tumefaction of the prepuce will have considerably subsided. A mortification of the prepuce is sometimes a consequence of chancres when attended with violent inflammation, even without any previous operation ; and I have seen cases where the glans and part of the penis have mortified, while the prepuce has kept its ground. But I should suspect in all such cases that there is some fault in the constitution, and that the inflammation is of the erysipelatous, not of the true suppurative kind. I have seen the mortification go so far as to remove the whole of the diseased prepuce, and the parts have put on so favourable an appearance that I have treated it as a common sore, and no bad consequences have happened. In this case the disease performed what is often recommended in other diseases of this part, that is, circumcision; but this is not always to be trusted to, for if absorption of the venereal matter has taken place previous to the mortification, a lues venerea will be the consequence, although the parts heal very readily. J

§ 5. Of the Constitutional Treatment of Phimosis.

In those cases where violent inflammation has attacked the seat of a chancre, producing phimosis, as before described, and often so as to threaten mortification, a question naturally occurs, what is to be done ? Is mercury to be given freely to get rid of the first cause ? or does that medicine increase the effect while it destroys the cause? JMotlung but experience can determine this. I should incline to believe that it is necessary that mercury should be given, for I am afraid our powers to correct such a constitution, while the first cause subsists, are weak. However, on the other^ hand, I believe the mercury should be given sparingly, for if it assists in disposing the constitution to such symptoms we are gaining ON THE TREATMENT OF CHANCRE. 199 nothing, but may lose by its use. I therefore do suppose that such medicines as may be thought necessary for the constitution should be given liberally, as well as the specific. Bark is the medicine that probably will be of most general use ; opium in most cases of this kind will also be of singular service. The bark should be given in large quantities, and along with it mercury, while the virus is still supposed to exist. Or if the inflammation has arisen early in the disease, they may be then given together, so as to counteract both diseases, and not allow the inflammation to come to so great a height as it would otherwise do if mercury was given at first alone. This inflammation may be so great in many cases, or be so predominant, that mercury may increase the disposition, and therefore become hurtful. Where this may be supposed to be the case, bark must be given alone.*

§ 6. Of the Treatment of the Paraphimosis from Chancre.

A prepuce in the state of inflammation and tumefaction, and which has been either kept back upon the body of the penis while inflaming, or pulled back when inflamed, seldom can be again brought forwards while in this state, therefore becomes also the subject of an operation, which consists in dividing the same part, as in the phimosis, only in a different way, arising from its difference of situation, the intention of which operation is to bring the prepuce, when brought forwards, to the state of a phimosis that has been operated upon. This operation becomes more necessary in many cases under this disease than under the phimosis:, because its consequences are generally worse; since, besides the real disease, viz. inflammation, tumefaction, ulceration, &c, there is a

* [In many cases of phimosis mercury is not necessary, because in many cases the affection arises not from a venereal chancre, but from a common sore : as, for instance, from that sort of ulceration which the author has denominated gonorrhoea of the glans and prepuce. When the sore is a chancre mercury must be used, and the sore will seldom be overcome without it, because washes and other topical applications, as well as diaphoretics and purgatives internally, though they exercise a certain degree of power over the inflammation, do not reduce the genuine venereal thickening. If the surgeon is in doubt as to the real nature of the sore within, he may suspend the use of mercury till the inflammation has been partly subdued by other means, and he has acquired evidence of its true character, from the obstinacy of the contraction, or the distinct perception of the chaucrous induration. But the presence of active inflammation forms no objection to the emuloyment of mercury. On the contrary, under such circumstances, mercury will in all cases be beneficial. Even when the prepuce is sloughing, it is not in general contraindicated, provided the bright arterial colour of the part, and the state of the pulse and of the skin, show that the arterial action is above the natural standard. The sloughing in such cases arises either from the confinement of matter within the prepuce, or from the excessive violence of the inflammation. In the first case it will be stopped by making an opening with a lancet at the part where the abscess is pointing; in the second case it will be most effectually limited by quickly subduing the inflammation; and this may be best accomplished by absolute rest, by the internal use of antimony and mercury, and by the frequent injection of saturnine washes under the prepuce.] 200 HUNTER ON THE VENEREAL DISEASE. mechanical cause producing its effects, by grasping the penis, which can of itself produce inflammation where the prepuce is naturally tight, as has been observed. From whatever cause it arises, it often produces mortification in the parts between the stricture and the glans if it is not removed. This removal sometimes happens naturally by the ulceration of the strictured part, but an operation is generally necessary, and it is more troublesome than in the former case, because the swelling on each side of the stricture covers or closes in upon the tight part, and makes it difficult to be got at. The best way appears to be to separate the two swellings as much as possible where you mean to cut, so as to expose the neck ; then take a crooked bistoury which is pointed, and passing it under the skin at the neck, divide it; no part of the two swellings on the sides need be divided, for it is the looseness of the skin in these parts which admits of their swelling. When this is done the prepuce may be brought forwards over the glans ; but as this disease arose from chancres which may require being dressed, and as the state of a phimosis is a very bad one for such treatment, it may be better, now that the stricture is removed, to let it remain in the same situation till the whole is well. If the paraphimosis has arisen from a natural tightness of the prepuce, and its being forced back from accident, then no particular treatment after the operation is necessary but to go on with the cure as recommended in chancres. It is indeed probable that in consequence of the violence produced by the position of the prepuce as also by the operation, a considerable inflammation may ensue; but as this will be an inflammation in consequence of violence only, local treatment for the inflammation will be sufficient. But if it is a paraphimosis in consequence of a diseased phimosis, then the same mode of treatment becomes equally necessary as was recommended in the phimosis attended with considerable inflammation; and probably rather more attention is necessary here, as violence has been added to the former disease.

§ 7. Of the Cure of Chancres by Mercury given internally.

While chancres are under local treatment, as before described, it is necessary to give mercurials internally, both for the cure of a chancre and the prevention of a lues venerea; and we may reasonably venture to affirm, that the venereal disposition of* chancre will hardly ever withstand both local and internal mercurials. In cases of chancres where local applications cannot easily be made, as in cases of phimosis, internal mercurials become absolutely necessary, and more so than if they could be conveniently and freely applied externally. However even in such cases, internal mercurials will in the end effect a cure, so that we need seldom if ever be under any apprehension of not curing such a disease. ON THE TREATMENT OF CHANCRE. 201 In every case of a chancre, let it be ever so slight, mercury should be given internally, even in those cases where they were destroyed on their first appearance. It should in all cases be given the whole time of the cure, and continued for some time after the chancres are healed ; for as there are perhaps few chancres without absorption of the matter, it becomes absolutely necessary to give mercury to act internally, in order to hinder the venereal disposition from forming.* How much mercury should be thrown into the constitution in the cure of a chancre, for the prevention of that constitutional affection, is not easily ascertained ; as there is in such cases no disease actually formed so as to be a guide, it must be uncertain what quantity should be given internally. It must in general be according to the size, number, and duration of the chancres. If large, we may suppose that the absorption will be proportioned to the surface, and if long continued, the absorption will be according to the time; and if they have been many, large, and continued long, then the greatest quantity is necessary. The circumstances therefore attending the chancre must be the guide for the safety of the constitution, especially in those cases where some stress In the cure is laid upon the external remedy. The mercury given to act internally must be thrown in either by the skin or stomach, according to circumstances. The quantity in either way should be such as may in common affect the mouth slightly, which method of giving mercury will be considered hereafter. . When the sore has put on a healthy look, when the hard basis has become soft, and it has skinned over kindly, it may be looked upon as cured. But in very large chancres it may not always be necessary to continue the application of mercury either for external or internal action till the sore is healed; for the venereal action is just as soon destroyed in a large chancre as it is in a small one, for every part of the chancre being equally affected by the mercury, is equally easily cured. But the skinning is different; for a large sore is longer in skinning than a small one. A large chancre therefore may be deprived of its venereal action long before it is skinned over; but a small one may probably skin over before the venereal poison is entirely subdued. In the latter case, both on account of the chancre and constitution, it will be erring on the safe side to continue the medicine a little longer, which will most certainly in the end effect a cure; for we may reasonably suppose that the quantity of mercury capable of curing a local effect, although assisted by local applications, or of producing in the constitution a

* Added : « When chancres are attended with a great degree of inflammation and swelling of the neighbouring lymphatic glands, there are pecu^ '"Uies m the constitution which are unfavourable to the use of mercury ; . should therefore in such cases be used with caution, and joined with such remedies as will make U less irritating to the constitution."—Home. 18 202 HUNTER ON THE VENEREAL DISEASE. mercurial irritation sufficient to hinder the venereal irritation from forming, will be nearly as much as will cure a slight lues venerea. I have formerly laid it down as a principle, that no new action will take place in another part of the body, however contaminated, whilst the body is under the beneficial operation of mercury ; but there are now and then appearances which occur under the cure that will at first embarrass the practitioner. I have suspected that the mercury flying to the mouth and throat has sometimes produced sloughs in the tonsils, and these have been taken for venereal. The following cases in some degree explain this. A young gentleman had a chancre on the prepuce, with a slight pain in a gland of one groin, for which I ordered mercurial ointment to be rubbed into the legs and thighs, especially on the side where the gland was swelled, and the chancre to be dressed with mercurial ointment. While he was pursuing this course the chancre became cleaner, the hardness at the base went off, and the pain in the groin was entirely removed. About three weeks after the first appearance of the disease he was attacked with a sore throat, and on looking into the mouth I found the right tonsil with a white slough, which appeared to be in its substance, with only one point yet exposed. From my mind being warped by the opinion that these complaints proceeded from the chancre, I immediately suspected that it was venereal; and the only way that I could account for this seeming contradiction, in one part healing while another was breaking out, was, that the healing sore was treated locally as well as constitutionally, while the tonsil, or the constitution at large, was only treated constitutionally, which was insufficient. Soon after this another gentleman was under my care for venereal scurfs, or eruptions on his skin, for which he used mercurial friction till his mouth became sore; and in this state he continued for three weeks, in which time the eruptions were all gone, discolourations being left only where the eruptions had been, yet at the end of three weeks a slough formed in one of the tonsils, exactly as in the former case. This made me doubtful how far such cases were venereal. I ordered the friction to be let off, to see what course the ulcers would take : the slough came out and left a foul sore. I waited still longer, and in a day or two it became clean and healed up. The first-mentioned case I did not see to an end ; but I learned that the patient continued the mercury and got well, and the ulcer in the throat was supposed to be venereal; but, from the circumstances of the other case, 1 now very much doubt of that. It is more than probable that these effects of mercury only take place in constitutions that have a tendency to such complamts in the throat. I know this to be the case with the last-mentioned gentleman; and it is also probable that there may be an increased disposition at the time, either in consequence of the mercury or some accidental cause. I have reason to suppose that mercury in some degree increases this disposition, which I shall further take notice of when treating of the cure of the lues venerea. OF THE CURE OF CHANCRES IN WOMEN. 203 In the cure of chancres I have sometimes seen, when the original chancre has been doing well and probably nearly cured, that new ones have broken out upon the prepuce, near to the first, and have put on all the appearance of a chancre; but such I have always treated as not venereal. They may be similar to some consequences of chancres, which will be taken notice of hereafter. As swellings of the absorbent glands take place in consequence of other absorptions besides that of poisons, we should be careful in all cases to ascertain the cause, as has been already described; and here it may not be improper still to observe further, that in the cure of chancres, swellings of the glands shall arise, even when the constitution is loaded with mercury sufficient for the cure of the sores; but then the mercury has been thrown into the constitution by the lower extremity, and therefore there is great room for suspicion that such swellings are not venereal, but arise from the mercury; for a real bubo, from absorption of venereal matter, if not come to suppuration, will give way to mercury rubbed into the leg and thigh. In such cases I have always desisted from giving the mercury in this way when I could give it by the mouth. CHAPTER IV.

OF THE CURE OF CHANCRES IN WOMEN.

The parts generally affected with chancres in this sex are more simple than in men, by which means the treatment in general is also more simple; but in most cases they require nearly the same, both in the local application of mercury, and in throwing it into the constitution. It may be supposed, however, that it will be necessary in many cases to throw into the constitution more mercury than in men, because in general there are more chancres, and the surface of absorption of course larger. nrnnt>r As it is difficult to keep dressings on the female parts, it is proper they should be washed often with solutions of mercury ; perhaps corrosive sublimate is one of the best, as it will act as a specific, and also as a stimulant when that is wanted; but in chancres that are very irritable, the same mode of treatment as was recommended in men is to be put in practice. Afterwards the parts may be besmeared with a mercurial application, either oily or watery, to be frequently repeated, according to the circumstances of the case. If the ulcers should have spread, or run up the vagina, great attention should be paid to the healing of them; for it sometimes; happens that the granulations contract considerably, so as to d.awtiie vagina into a small canal; at other times the granulations wdl urn e into one another, and close the vagina up altogether; therefore id 204 HUNTER ON THE VENEREAL DISEASE. such cases it will be necessary to keep some substance in the vagina till the sores are skinned, for which purpose probably lint may be sufficient. CHAPTER V.

OF SOME OF THE CONSEQUENCES OF CHANCRES, AND THE TREAT- MENT OF THEM.

After the chancres have been cured, and all venereal taint removed, it sometimes ha-pens that the prepuce still retains a considerable degree of tumefaction, which keeps up the elongation and tightness which it acquired from the disease, so that it cannot be brought back again upon the penis to expose the glans. For this perhaps there is, in many cases, no cure; however, it is necessary to try every possible means. The steam of warm water, fomentations with hemlock, and also fumigations with cinnabar, are often of singular service in this case. But if the parts still retain their size and form, it may be very proper to remove part of the overgrown prepuce ; how much, must be left to the discretion of the surgeon. I should suppose that all that part which projects beyond the glans penis may be cut away. The best way of removing it is by the knife ; but great care should be taken to distinguish first the projecting prepuce from the glans. When this is perfectly ascertained, the penis being held horizontally, an incision may be made on the upper surface, and followed down with caution; because if the incision should be too near the glans there may be danger of cutting it. The parts may be allowed to heal with any common dressings, as it is to be considered as a fresh wound; however it will not heal so readily as a fresh wound made in an entirely sound part, because the operation consists in taking away only a superfluous part of a diseased whole; and what is left is diseased, but not so as to produce any future mischief. Some care may be necessary in the healing of the parts, for it is very possible that the cicatrix may contract, and still form a phimosis. This will be best prevented by the patient himself if he brings the prepuce often back upon the penis; but it should not be attempted till the part is nearly healed ; and it is to be performed with great care, and slowly.

§ 1. Of Dispositions to new Diseases during the cure of Chancres.

Chancres, both in men and women, often acquire new dispositions in the time of the cure, which are of various kinds, some of which retard the cure, as described, and, when the parts are cured, OF THE CONSEQUENCES OF CHANCRE, ETC. 205 leave them tumefied and indolent, as in the enlarged prepuce. In others a new disposition takes place, which prevents the cure or healing of the parts, and often produces a much worse disease than that from which it arose. They also become the cause of the formation of tumours on these parts, which will be taken notice of hereafter. Such new dispositions take place oftener in men than in women, probably from the nature of the parts themselves. They seldom or never happen but when the inflammation has been violent, which violence arises more from the nature of the parts than the disease, and therefore belongs more to the nature of the parts or constitution than to the disease. However, I can conceive it may also take place where the inflammation has not been violent. In general they are supposed to be cancerous, but I believe they seldom are, although it is not impossible that some may be so. Of this kind may be reckoned those continued and often increased inflammations, suppurations, and ulcerations, becoming diffused through the whole prepuce, as also all along the common skin of the penis, which becomes of a purple hue ; the cellular membrane everywhere on the penis being very much thickened, so as to increase the size of the whole considerably. The ulceration on the inside of the prepuce will sometimes increase and run between the skin and the body of the penis, and eat holes through in different places till the whole is reduced to a number of ragged sores. The glans often shares the same fate, till more or less of it is gone; frequently the urethra at this part is wholly destroyed by ulceration, and the urine is discharged some way further back. If a stop is not put to the progress of the disease, the ulceration will continue till the parts are entirely destroyed. I suspect that some of these cases are scrofulous. As this is an acute case, immediate relief should be given, if possible; but as it may arise from various peculiarities in the constitution, and as these peculiarities are not at first known, no rational method can be here determined. The decoction of sarsaparilla is often of service in such cases, but requires to be given in large quantities. The German diet-drink* has been of singular service ; I knew a case of this kind cured by it, after every known remedy had been tried. The extract of hemlock is sometimes of service. I have

* The following formulae have been much recommended as diet-drinks. Take of crude antimony, pulverized, tied up in a bit of rag; pumice-stone, pulverized, tied up in the same, of each one ounce; China-root, sliced; sarsaparilla-root, sliced and bruised, of each half an ounce; ten walnuts, with their rinds, bruised ; spring water four pints, boil to half that quantity ; filter it, and let it be drunk daily in divided doses. ,. Take sarsaparilla, Saunders-wood, white and red, of each three ounces; liquorice and mezereon, of each half an ounce ; lignum rhodium, guaiacum, sassafras, of each one ounce; crude antimony, two ounces; mix them and •»^se,ner» in boiling water, ten pints, for twenty-four hours, and afterwards boil them to nve pints, of which let the dose be from a pint and a half to four pints a day. 206 HUNTER ON THE VENEREAL DISEASE. known sea-bathing cure these complaints entirely. A gentleman came from Ireland with a complaint of this kind, and after having tried every common and known method without effect, as sarsaparilla, hemlock, German diet-drink, and after having used a great variety of dressings (which were all at last laid aside, and opium only retained to quiet the pain), he bathed in the sea and got well. It may be sometimes necessary to pass a bougie, to hinder the orifice of the urethra from closing or becoming too small in the time of healing in such cases.*

* [The description of the author is so vague that it is difficult to know with certainty what species of sore he here intends to designate. But it is probable that he chiefly refers to those sores which are called phagedenic, and which are of sufficient importance to require a particular description. The name phagedenic has been given to them because they have been supposed to be the same with the ulcers described by Celsus under the name of phagedaena. Though the correctness of this supposition may be questioned, yet there is a convenience in retaining a name which not unaptly characterizes the ulcer, whether we regard the occasion, rapidity of its progress, or the most remarkable features which distinguish its aspect. It can scarcely be doubted that phagedenic ulcers arise from the application of a virus, since there is no satisfactory evidence that they ever occur where the party has not been exposed to infection, and since they are as constantly followed by secondary symptoms, as the genuine forms of cancre which have been previously described. Nor, though much attention has been paid to the subject, has it been possible to trace such a constant distinction as would establish that the virus which produces them is different from that which gives origin to the common Hunterian chancre. The characters of the phagedenic sore are very different from those of a common chancre; and if there is a diversity of virus, this diversity should be constant, and should be capable of being traced equally in the giver and the recipient; in the party from which the infection is derived, as well as in that to which it is communicated. But it has not been found possible to ascertain that this is the case. On the contrary, the phagedenic sore has in several instances appeared to have been derived from individuals who have suffered from the common forms of chancre. The phagedenic sore begins with slight tumefaction of the part, and slight excoriation of the surface. This excoriated surface soon becomes foul, being covered with a yellow slough, and discharging a watery sanies of a brownish tinge. As the sore destroys the part on which it is situated the surface becomes uneven, and the outline of the sore irregular in shape, and, as it were, scolloped. These appearances are produced by the mode of progress, which is not regular and uniform in every direction, but proceeds in some parts more rapidly than in others. The central part, and perhaps one of the edges, then ceases to spread, and becomes clean, while on other sides the foul character remains, and the sore continues to extend. The part which is spreading is always somewhat tumefied, but the tumefaction is that of common inflammation, and is not distinctly defined, like that, of an ordinary chancre. It does not terminate abruptly, but passes imperceptibly into the surrounding structure. In fact it is merely caused by the irritation of the spreading sore: the clean edge is altogether free from it. As soon as a part cleans, the tumefaction subsides, though the ulceration may remain long afterwards unhealed. The tumefaction cannot be said to precede the ulceration ; it rather attends the sloughing, if that can be called sloughino- which is in general only foul ulceration. The phagedenic sore may destroy any part on which it is placed, but its ravages involve the cellular membrane more readily than either the prepuce or the body of the penis. The consequence is, that in most cases it burrows between the body and the skin of the penis, dissecting in its course the corpora cavernosa from the integuments, and creeping upwards between these parts, OF THE CONSEQUENCES OF CHANCRE, ETC. 207 § 2. Of Ulceration resembling Chancres.

It often happens that after chancres are healed, and all the virus gone, the cicatrices ulcerate again, and break out in the form of chancres.

often as far as the os pubis. Under these circumstances, the bottom of the sore cannot be fully exposed ; the part which is within view is generally clean, and sometimes slowly healing, while the portion which is concealed is foul and yellow, and secretes large quantities of a thin brownish discharge. This spreading edge is attended by the usual tumefaction, which may be felt externally as a hard ring encircling the body of the penis, marking the distance to which the sore has extended, and in the progress of the complaint approaching nearer and nearer to the root of the penis. As long as this thickened edge is to be felt, so long the sore is spreading. If the bottom of the sore cleans and tends to heal, the improvement may be known by the subsidence of this thickening, as immediately and as certainly as if the whole of the surface were exposed to view. Under common circumstances the phagedenic sore spreads by foul ulceration, and eats its way very slowly, and almost imperceptibly. But it is subject to occasional accesses of sloughing, in which large portions of the prepuce, the glans, or the corpus spongiosum, mortify and separate. There are few cases of long standing in which such sloughing has not occurred ; and in most instances a portion oAhe urethra has been destroyed by it, and an opening has been formed, at which the urine escapes, about an inch above the. natural meatus. The suddenness of these attacks, and the irremediable destruction which they occasion, render it necessary that the treatment should always be conducted with a view to their occurrence. The discharge from the phagedenic sore is profuse and unhealthy; but it does not seem, like the discharge of the common chancre, to affect the surfaces with which it comes into contact. It is common that the prepuce and the glans should be almost constantly bathed in it; yet it is very rarely or never that other sores arise on these parts in consequence. Again, the contiguous surfaces are not affected. The sore may be situated on the body of the penis, while the prepuce in contact with it shall remain free from ulceration. It is not uncommon that the phagedenic sore should be situated on one side of the meatus urinae, and should destroy a considerable portion of the glans before it is arrested ; yet the affection will not extend to the other side of the meatus, although the ulcerated surface is allowed to remain perpetually in contact with it. The phagedenic sore is attended with some, but not with acute inflammation. The pain, except, during an attack of sloughing, is not very severe. The prepuce is usually red, sometimes purple, almost always loaded with serum, and tumid ; but it is not generally indurated, or firm to the touch ; nor is the colour of that bright scarlet which attends acute phimosis from common chancre. Yet there is more constitutional disturbance : the pulse is usually quick and excitable, the skin hot, the appetite indifferent, and the sleep restless and disturbed. It is rare that a suppurating bubo should arise from a phagedenic sore. A gland in the groin sometimes enlarges, but it is seldom very painful, and generally subsides spontaneously in less than a week. The secondary symptoms which follow the phagedenic sore are peculiarly severe and intractable. They commonly consist of rupia, sloughing of the throat, ulceration of the nose, severe and obstinate muscular pains, and afterwards inflammation of the periosteum and bones. Similar complaints will follow the ordinary chancre; but when they follow a phagedenic sore they are very difficult to be cured ; and it is not uncommon that the constitution of the patient should at length give way under them, and that the case should terminate fatally. Tf the description of these sores is compared with that of a common chancre, itself No such induration is found in the phagedenic sore; the thickening 208 HUNTER ON THE VENEREAL DISEASE. Although this is most common in the seat of the former chancres, yet it is not ahvavs confined to them, for sores often break out on other parts of the prepuce ; but still they appear to be a consequence of a venereal complaint having been there, as they seldom attack those who never had gonorrhoea or chancres. They often have so much the appearance of chancres, that I am persuaded many are treated as venereal that are really not such: they differ from a chancre in general by not spreading so fast, nor so far; they are not so painful, nor so much inflamed, and have not those hard bases that the venereal sores have, nor do they produce buboes. Yet a malignant kind of them, when they attack a bad constitution, may be taken for a mild kind of chancre, or a chancre in a good constitution.* Some stress is to be laid upon the account that the patient gives of himself; but when there is any doubt, a little time will clear it up. I have seen the same appearances after a gonorrhoea, but that more rarely happens. It would appear that the venereal poison could leave a disposition for ulceration of a different kind from what is peculiar to itself. I knew one case where they broke out regularly every two months, exactly to a day.

which does occur does not differ from that which is met with in other sores, and is merely an attendant on the unhealthy state of the ulcer. The common chancre spreads equally in all directions. The phagedenic sore spreads irregularly, and frequently heals at one edge while it is spreading at another. The common chancre tends to multiply and to produce similar ulcers on the surfaces which are in contact with it. The phagedenic sore remains single, and the contiguous surfaces are unaffected. There is also a difference, though less clearly defined, in the secondary symptoms which follow these two species of sore, and a different treatment must be adopted in the cure. If the phagedenic sore is treated with a full course of mercury, it is most frequently found that the improvement in the first instance is more immediate and more decided than in the case of common chancre. In a very few days the inflammation subsides, the surface cleans, and the sore begins to heal. But this amendment is usually only temporary : it generally happens that in a few days more, if the mercury is continued, and especially if the effect on the system is at all excessive, the aspect changes, the colour of the surrounding parts becomes dark and purple, sudden sloughing comes on, and the whole surface of the sore, and often much of the prepuce and of the penis, is involved in it. On the other hand, if mercury is entirely avoided, and such treatment only is adopted as would be employed in a common sore, the ulcer obstinately retains its unhealthy character, and makes constant, though less rapid, progress by foul ulceration. Mercury is of great service in the treatment of the phagedenic sore, but if its depressing defects are allowed to come on, the consequence is, almost always, sloughing. It must therefore be so employed as to avoid these effects : it must be administered in those doses, and in those forms which least depress the circulation ; and it must be combined with such medicines as are calculated at the same time to support the system. The oxymuriate of mercury, given in the dose of an eighth of a grain twice in the day, and in unison with decoction of sarsaparilla, is the safest and most efficient preparation. But even in this form the effect must be watched ; and if the integuments in the neighbourhood of the sore should become pale or livid, or if much general languor is induced, the remedy must be intermitted, and resumed, only after these symptoms of impeding sloughing have disappeared. It must not be omitted, that the internal use of the hydriodate of potass has often great effect on this form of disease.] * Added : " I have seen several that have puzzled me extremely."—Home. V OF THE CONSEQUENCES OF CHANCRE, ETC. 209

As they are not venereal, their treatment becomes difficult; for the cure consists more in preventing a return than in the healing up of the present sores. They require particular attention ; for although they are not dangerous, they are often troublesome, keeping the mind in suspense for months. I have tried a great variety of means, but with little success; yet they have in general got well in the end. In the following case, the lixivium saponarium produced a speedy cure. A gentleman had three sores broke out on the prepuce, which had very much the appearance of mild chancres. As I was doubtful of their nature, I waited some time, and only ordered them to be kept clean. As they did not get well, several things were tried. Mercurial dressings were applied, but they always produced considerable irritation, and it was necessary to leave them off. The mercurius calcinatus was given by way of trial, and to secure the constitution, but the sores continued the same. They were eat down with the lunar caustic, which appeared to have a better effect than any other thing tried ; but still they were not healed at the end of five months. I ordered forty drops of the lixivium saponarium to be taken every evening and morning in a bason of broth. After using it three days he observed a considerable alteration in the sores, and in six days they were perfectly skinned over. He had formerly had such sores often, which had always been treated as venereal; but he began to doubt whether they really were so, from their getting so soon well in the present instance by the lixivium. I knew a gentleman who had these sores breaking out and healing again for years. By bathing in the sea for a month or two, they healed up, and never afterwards appeared.

§ 3. Of a Thickening and Hardening of the Parts. In some cases the parts do not ulcerate, but appear to thicken and become hard or firm; both the glans and prepuce seem to swell, forming a tumour or excrescence from the end of the penis, in form a good deal like a cauliflower, and, when cut into, showing radii running from its base or origin towards the external surface, becoming extremely indolent in all its operations. This gives more the idea of a cancer than the first, being principally a new-formed substance. However, it is not always a consequence of the venereal disease, for I have known it to arise spontaneously. This disease appears to be a tumour of so indolent a kind that I do not know any medicine that stands the least chance of performing a cure. I have amputated them, and have also seen the same thing done by others, from the idea of their being cancerous, and the remaining part of the penis has healed kindly. In most of these cases a considerable part of the penis must be removed. Immediately after the amputation, a suitable catheter should be introduced into the urethra; for if no such precaution is 19 210 HUNTER ON THE VENEREAL DISEASE. made use of, the consequences must be troublesome; for the first dressings become cemented to the orifice by the extravasated blood, and prevents the patient's making water, which must be attended with obvious inconveniences. This was the case with a patient whose penis I amputated.

§ 4. Of Warts. Another disposition which these parts acquire from the venereal poison is the disposition to form excrescences or cutaneous tumours, called warts. This disposition is strongest where the chancres were, and indeed chancres often heal into warts; but perhaps the parts acquire this disposition from the venereal matter having been long in contact with their surfaces, for it often happens after gonorrhoea, where there had been no chancres; and probably it is only in those cases where the venereal matter had produced the venereal stimulus upon the glans and prepuce, forming there what may be called an insensible gonorrhoea. A wart appears to be an excrescence from the cutis, or a tumour formed upon it, by which means it becomes covered with a cuticle, which, like all other cuticles, is either strong and hard or thin and soft, just as the cuticle is which covers the parts from w7hence they arise. They are radiated from their basis to the circumference, the radii appearing at the surface pointed or granulated, much like granulations that are healthy, except that they are harder and rise above the surface. It would appear that the surface on which each is formed has only the disposition to form and, because the surrounding and connecting surface does not go into the like substance: thus a wart once begun does not increase in its basis, but rises higher and higher. They have an increasing power within themselves: for, after rising above the surface of the skin, on which they are not allowed to increase in breadth at the basis, they swell out into a round thick substance, which becomes rougher and rougher. This structure often makes them liable to be hurt by bodies rubbing against them; and often from such a cause they bleed very profusely, and are very painful. These excrescences are considered by many not as simply a consequence of the venereal poison, but as possessed of its specific disposition, and therefore they have recourse to mercury for the cure of them; and it is asserted that such treatment often removes them. Such an effect of mercury I have never seen, although given in such a quantity as to cure in the same person recent chancres and sometimes a pox. As these substances are excrescences from the body, they are not to be considered as truly a part of the animal, not being endowed with the common or natural animal powers, by which °means the cure becomes easier. They are so little of the true animal, and so much of a disease, that many trifling circumstances make them decay; an inflammation in the natural and sound parts round the wart will give it a disposition to decay; many stimuli applied to the surface will often make them die. Electricity will produce OF THE CONSEQUENCES OF CHANCRE, ETC. 211 action in them which they are not able to support; an inflammation is excited round them, and they drop off. From this view of them, the knife and escharotics must appear not always necessary, although these modes will act more quickly than any other in many cases, especially if the neck is small. In such-formed warts perhaps a pair of scissors is the best instrument; but where cutting instruments of any kind are horrible to the patient, a silk thread tied round their neck will do very well; but, in whichsoever way it is separated, it will be in general necessary to touch the base with caustic. Escharotics act upon warts in two different ways, namely, by deadening a part and stimulating the remainder; so that by the application of escharotic after escharotic the whole decays tolerably fast, and it is seldom necessary to eat them down to the very root, as the basis or root often separates and is thrown off. This however is not always the case, for we find that the root does not always separate, and that it will grow again; therefore in such cases it is necessary to eat down lower than the general surface to remove the root. Any of the caustics, such as the lapis septicus, as also the metallic salts, such as the lunar caustic, blue vitrei, &c, have this power. The rust of copper and savine-leaves mixed are one ol the best stimulants. . , , After they have been to appearance sufficiently destroyed, they often arise anew, not from any part being left, but from the surface of the cutis having the same disposition as before. This requires a repetition of the same practice, so as to take off that surface ol the cutis. $ 5. Of Excoriations of the Glans and Prepuce. It very often happens that the surface of the glans and inside of the prepuce excoriate, becoming extremely tender, and then a matter oozes out. The prepuce in such cases often becomes a little thickened, and sometimes contracts in its orifice, both which circumstances render the inversion of it difficult and painful. Whether this complaint ever arises from a venerea cause is not certain, as it often takes place where there never has been any venereal taint. , , ,. . . .. , n This disease is in the cutis ; and under such a disposition it has no power of forming a good cuticle. It is very similar to a gonorhoea in this part, but is not venereal. . , . Drawing the prepuce back, and steeping the parts in a solution of lead, often takes off the irritation, and a sound cuticle is formed. Spirits diluted often produce the same effect; the unguentum citrinum of the Edinburgh Dispensatory, lowered by mixing with it equal parts of hog's-lard, is often of singular service in such cases. But there are cases which bid defiance to all our applications, in which 1 have succeeded by desiring the person to leave ttegto uncovered, which produced the stimulus of necessity for the formation of a natural cuticle. 212 HUNTER ON THE VENEREAL DISEASE PART V. CHAPTER I.

A knowledge of the absorbing system, as it is now established, gives us considerable information respecting many of the effects of poisons, and illustrates several symptoms of the venereal disease, in particular the formation of buboes. Prior to this knowledge we find writers at a loss how to give a true and consistent explanation of many of the symptoms of this disease. The discovery of the lymphatics being a system of absorbents has thrown more light on many diseases than the discovery of the circulation of the blood : it leads in many cases directly to the cause of the disease. The immediate consequence of the local diseases, gonorrhoea and chancre, which is called bubo, as also the remote, or lues venerea, arise from the absorption of recent venereal matter from some surface where it has either been applied or formed. Although this must have been allowed in general ever since the knowledge of the disease and of absorption, yet a true solution of the formation of bubo could not be given till we had acquired the knowledge of the lymphatics being the only absorbents. Upon the old opinion, of absorption being performed by the veins, the lues venerea could easily have been accounted for, because it could as readily be produced by the absorbing power of the veins, if they had such, ashy the lymphatics; but the difficulty was to say how the bubo was formed. There they seemed to be at a loss to account for this disease, yet they sometimes expressed themselves as if they had some idea of it, although at the same time they could have no clear notions of what they advanced : nor could they demonstrate what they said from the knowledge of the parts and their uses. Buboes are by some imputed to the stopping of a gonorrhoea, or as they express it, driving it to the glands of the groin, comformably to the idea they had of the cause of the swelling of the testicle But this is not just, for we know of no such power as repulsion • and if it was driven there it could not be by stopping the formation of matter, but by increasing the absorption, of which they had no idea. J When we examine the opinion of authors concerning the forma- OF BUBO. 213 tion of bubo, prior to the knowledge of the power of absorption in the lymphatics, we shall find them making use of terms which they could not possibly understand. For instance, Heister says, "They are of two kinds, one venereal, and the other not; but he does not say that the venereal arises only from impure coition. Astruc says, p. 326, that some buboes arise immediately from impure coition, and these he calls essential; others from suppressed gonorrhoea, or a small discharge, or from chaneres of the penis, and these he calls symptomatic: lastly, that they arise spontaneously without any immediate previous coition, and are a pathognomonic sign of a hidden pox. In p. 327 he shows the impossibility of this last happening from what we now call or understand by a lues venerea; but in p. 328 he explains what he calls a latent lues venerea, which is local affection produced as he supposes from a lues venerea, but which most probably never yet happened; and if ever they had arisen from such a cause, even the absorption of their matter could not produce a venereal bubo, as will be explained. In short, as he understood not the true absorbing system, his ideas are become now unintelligible.* We find Cowper, Drake, and Boerhaave, as well as Astruc, speaking of the vitiated lymph not passing the glands, therefore inflaming them; also of the inspissated lymph passing, either by the circulation of the blood, that is, from the constitution to these glands, (an opinion held by some to this day,) or by a shorter course, viz. the lymphatic vessels which go to the inguinal glands. They also speak of the swelling of the inguinal glands, or venereal buboes, from the contagion being communicated by the resorbent lymphatics. Drake even speaks more pointedly; and, if we consider him no further, he would almost make us believe that he knew that the lymphatics were the absorbents; but as he has no such ideas when treating of those vessels expressly, we are not to give him credit for it. His words are: " The venereal bubo may very likely take its rise from some parts of the contagious matter of claps sucked up by the lymphatics of the penis, and thence imported to the inguinal glands, where they deposit their liquor; and thence it well behoves the surgeon to be as early as may be in the opening of such tumours, before by the exporting vessels of that class the poison is carried further into the blood, which very probably may be the case where such tumour ariseth immediately upon the stopping of a gonorrhoea, as does the hernia humoralis. But when the same appears some months after that was removed, we are to suppose, as in cases of other poisons laying hold of the blood, by the strength of Nature it is thrown forth, either by means of the lymphatics of the blood-vessels themselves, if not spewed out of the nervous tubes, as Wharton surmised, and deposited in these emunctories."

*The above extracts are from the English edition, published in the year 1754. 19* 2H HUNTER ON THE VENEREAL DISEASE. Here he compares it to the formation of a hernia humoralis, which plainly shows that he understood neither of them. Even so late as the year 1748, we do not find any new ideas on this subject: Freke says, " By sealing up the mouths of the glands of the urethra, the poison is thence, by the ducts leading to the inguinal glands, conveyed to them." In the year 1754, eight years after Dr. Hunter had publicly taught his opinion of the lymphatics being a system of absorbents, we find a treatise on this disease by Mr. Gataker, where as little new is advanced on this subject as in any of the former. When we come so low down as the year 1770, in an abridgment of Astruc, by Dr. Chapman, (2d edit.) in which he introduces his own knowledge and ideas, we find the absorbing power of the lymphatics brought in as a cause of the formation of buboes; but by this time the knowledge of the lymphatics being the system of absorbents was in this country generally diffused. The doctrine of absorption being now perfectly understood, we have only to explain the different modes in which it may take place. The venereal matter is taken up by the absorbents of the part in which it is placed; and although the absorption of the matter and the effects after absorption are the same, whether from the matter of the gonorrhoea or chancre, yet I shall divide the absorption into three kinds, according to the three different surfaces from which the matter may be absorbed, beginning with the least frequent. The first and most simple is where the matter either of a gonorrhoea or chancre has only been applied to some sound surface, without having produced any local effect on the part, but has been absorbed immediately upon its application. Instances of this I have seen in men, and such are perhaps the only instances that can be depended upon; for it is uncertain in many cases whether a woman has a gonorrhoea or not. I think, however, I may venture to affirm that I have seen it in women, or at least there was every reason to believe that they had neither chancre nor gonorrhoea preceding, as there was no local appearance of it, nor did they communicate it to others who had connexion with them. It must be allowed that this mode of absorption is very rare; and if we were to examine the parts very carefully, or inquire of the patients very strictly, probably a small chancre might be discovered to have been the cause, which I have more than once seen. For, when we consider how rarely it happens from a gonorrhoea, in which the mode of absorption is similar, we can hardly suppose it probable that it should here arise from simple contact, the time of the application of the venereal matter being commonly so very short. We might indeed suppose the frequency to make up for the length of time, which we can hardly allow, for the same frequency should give the chance of producing it locally. Therefore very particular attention should be paid to all the circumstances attending such cases. There is however no great reason why it should not happen, and OF BUBO. 215 the possibility of it lessens the faith that is to be put in the supposition that the disease may be years in the constitution before it appears; for whenever it does appear in a lues venerea its date is always carried back to the last local affection, whether gonorrhoea or chancre, and the latter connexions are never regarded. The second mode of absorption of this matter is more frequent than the former, and it is when the matter applied has produced a gonorrhoea; and it may happen while the complaint is going on, either under a cure or not. Some of the matter secreted by the inflamed surfaces having been absorbed and carried into the circulation, produces the same complaints as.in the former case, by which means the person gives himself the lues venerea. The third mode is the absorption of the matter from an ulcer, which may be either a chancre, or a bubo. This mode is by much the more frequent, which, with many other proofs, would show that a sore or ulcer is the surface most favourable for absorption. Whether ulcers in every part of the body have an equal power of absorption I have not been able to determine ; but I suspect that an ulcer on the glans is not so good a surface for absorption as one on the prepuce, although I have seen both buboes and the lues venerea arise from the former, but not so often as from the latter. To these three methods may be added a fourth, absorption from a wound, which, I have already remarked, is perhaps not so frequent as any of the former. As the venereal poison has the power of contaminating whatever part of the body it comes in contact with, it contaminates the absorbent system, producing in it local venereal complaints. It is hardly necessary to observe, that what is now commonly understood by a bubo, is a swelling taking place in the absorbing system, especially in the glands, arising from the absorption of some poison, or other irritating matter; and when such swellings take place in the groin they are called buboes, whether from absorption or not, but are most commonly supposed to be venereal, even although there has been no visible preceding cause. This has been so much the case, that all swellings in this part have been suspected to be of this nature; femoral ruptures and aneurisms of the femoral artery have been mistaken for venereal buboes. I shall call every abscess in the absorbing system, whether in the vessels or the glands, arising in consequence of the absorption of veneral matter, a bubo. This matter, when absorbed from either of the four different surfaces, which are common surfaces, wounds, inflamed surfaces, and ulcers, is carried along the absorbent vessels to the common circulation, and its passage often produces the specific inflammation in these vessels, the consequence of which is the formation of buboes, which are venereal abscesses, exactly similar in their nature and effects to a chancre, the only difference being in size. As the absorbents with the glands are immediately irritated by the same specific matter which has undergone no change in its passage, the 216 HUNTER ON THE VENEREAL DISEASE. consequent inflammation must therefore have the same specific quality, and the matter secreted in them be venereal.* As this system of vessels may be divided into two classes, the vessels themselves and their ramifications and convolutions, called the lymphatic glands, I shall follow the same division in treating of their inflammations. Inflammation of the vessels is not nearly so frequent as that of the glands. In men such inflammations, in consequence of chancres upon ihe glans or prepuce, generally appear like a cord leading along the back of the penis from the chancres. Sometimes they arise from the thickening of the prepuce in gonorrhoeas, that part in such cases being generally in a state of excoriation, as was described when I treated of that form of the disease. These cords often terminate insensibly on the penis, near its root, or near the pubes; at other times they extend further, passing to a lymphatic gland in the groin: this cord can be easily pinched up between the finger and thumb, and it often gives a thickness to the prepuce, making it so stiff at this part as to make the inversion of it difficult, if not impossible, producing a kind of phimosis. I think I have observed this appearance to arise as frequently from the gonorrhoea, when attended with the before-mentioned inflammation and tumefaction of the prepuce, as from chancres; which, if my observation is just, is not easily accounted for. I have observed that absorption is more common to ulcers than inflamed surfaces, or at least the formation of a bubo in the gland, and its effects in the constitution are more common from an ulcer; but it may be remarked, that the inside of the prepuce, from whence this cord appears to arise, is in an excoriated state. It is possible that this effect may arise from the lymphatics sympathizing with the inflammation of the urethra, but 1 believe the affection is truly venereal; or it is possible that even the absorption of the coagulable lymph, which was produced from the venereal inflammation, and which is the cause of the tumefaction, may have the power of contamination, as appears to be the case in the cancer. The thickening, or the formation of this hard cord, probably arises from the thickening of the coats of the absorbents, joined with the extravasation of coagulable lymph, thrown in upon its inner surface, as in inflamed veins. This cord often inflames so much as to suppurate, and sometimes in more places than one, forming one, two, or three buboes, or small abscesses in the body of the penis. When this is goino- on we find in some parts of this cord a circumscribed hardness; then suppuration takes place in the centre, the skin beo-ins to inflame, the matter comes nearer to it, and the abscess opens like any other abscess. J

*I do not know how far this reasoning will hold good in all cases of poisons, for I very much suspect that the bubo, that is sometimes formed in consequence of inoculation of the small-pox, does not produce variolous matter. The natural poisons, in producing buboes, certainly do not form a poison similar to them- S6i V6Sa OF BUBO. 217 I have seen a chain of these buboes, or little abscesses, along the upper part of the penis, through its whole length. This may be supposed to be exactly similar to the inflammation and suppuration of a vein after being wounded and exposed. Inflammation of the glands is much more frequent than the former, and arises from the venereal matter being carried on to the lymphatic glands, the structure of which appears to be no more than the ramifications and reunion of the absorbent vessels, by which means they form these bodies. From this structure we may reasonably suppose that the fluid absorbed is in some measure detained in these bodies, and thereby has a greater opportunity of communicating the disease to them than to the distinct vessels, where its course is perhaps more rapid, which may account for the glands being more frequently contaminated. Swellings of these glands are common to other diseases, and should be carefully distinguished from those that arise from the venereal poison. The first inquiry should be into the cause, to see if there is any venereal complaint at some greater distance from the heart, as chancres on the penis, or any preceding disease on the penis ; to learn if mercurial ointment has been at all applied to the legs and thighs of that side, for mercury applied to those parts, for the cure of a chancre, will sometimes tumefy the glands, which has been supposed to be venereal. We should further observe, if there be no preceding disease in the constitution, such as a cold, fever, &c, the progress of the swelling with regard to quickness is also to be attended to, as also to distinguish it from a rupture, lumbar abscess, or aneurism of the crural artery. Perhaps these bodies are more irritable, or more susceptible of stimuli than the vessels. They are certainly more susceptible of sympathy ; however, we are not yet sufficiently acquainted with the use of these glands to be able to account satisfactorily for this difference. It would appear in some cases that it is some time after the absorption of the venereal matter before it produces its effects upon the glands ; in some it has been six days at least. This could only be known by the chancres being healed six days before the bubo began to appear ; and in such cases it is more than probable that the matter had been absorbed a much longer time before, for the last matter of a chancre most probably is not venereal; and indeed it is natural to suppose that the poison may be as long before it produces on action on the parts, when applied in this way, as it is either in the urethra or in forming a chancre, which I have shown to be sometimes six or seven weeks. The glands nearest to the seat of absorption are in general the only ones that are attacked, as those in the groin, when the matter has been taken up from the penis in men: in the groin, between the labia and thigh, and the round ligaments, when absorbed from the vulva, in women. I think there is commonly but one gland at 218 HUNTER ON THE VENEREAL DISEASE. a time that is affected by the absorption of venereal matter, which, if so, becomes in some sort a distinguishing mark between venereal buboes and other diseases of these bodies. We never find the lymphatic vessels or glands, that are second in order, affected, as those along the iliac vessels or back; and I have also seen when the disease has been contracted by a sore, or cut upon the finger, the bubo come on a little above the bend of the arm, upon the inside of the biceps muscle; and in such where the bubo has come in that part, none has formed in the armpit, which is the most common place for the glands to be affected by absorption. But this is not universal, although common, for I was informed by a gentleman who contracted the disease in the before-mentioned way, that he had buboes both on the inside of the biceps muscle and in the armpit. Another case of this kind I have heard of since; why it is not more common is perhaps not easily explained. It might be supposed that the matter was weakened, or much diluted by the absorptions from other parts by the time it gets through these nearest ramifications, and therefore has not power to contaminate those which are beyond them ; but it is most probable that there are other reasons for this. I once suspected that the nature of the poison was altered in these glands as it passed through them, which was the reason why it did not contaminate the second or third series of glands ; and also why it did not affect the constitution in the same way as it did the parts to which it was first applied ; but this explanation will not account for the next order of glands to suppurating buboes not being affected by the absorption of venereal matter. It appears to me that the internal situation of the other glands prevents the venereal irritation from taking place in them ; and this opinion is strengthened by observing when one of these external glands suppurates and forms a bubo, which is to be considered as a large venereal sore or chancre that the absorption from it, which must be great, does not contaminate the lymphatics or glands next in order, by the venereal matter going directly through them. & If this be true then the skin would seem to be the cause of the susceptibility of the absorbents to receive the irritation. Whether the skin has the power inherent in itself, or acquires it from some other circumstance as air, cold, or sense of touch, is not easily ascertained ; but whichever it be, it shows that the venereal matter of itself is not capable of irritating, and that it requires a second principle to complete its full effect that is, a combination of the nature of the poison and the influence of the skin, and that influence must be by sympathy, and therefore weaker than if acting in the s"me part, that is, the skin itself, which perhaps is the refson whv uhe venereal matter does not always affect th™« \Z i j ,y . while it always does the skinTif^nsened into It *""* *"* ^^ The situation of buboes arising from the venereal disease in the penis is, in men, in the absorbent D-knd« „f tu • uls.erase ln tne rhcea is the cause of n h.,CT g|a™s of the groin; if a gonorrnoea is tne cause ol a bubo, one groin is not exempted more than OF BUBOES IN WOMEN. 219 the other; both may be affected : but if a bubo arises in consequence of a chancre, then the groin may be generally determined by the seat of the chancre, for if the chancre is on one side of the penis then the bubo will commonly be on that side : however, this is not universally the case; for I have known instances, although but few, where a chancre on one side of the prepuce or penis has been the cause of a bubo on the opposite side, which, if arising from that chancre, is a proof that the absorbents either anastomose, or decussate each other. If the chancre be on the fraenum, or on the middle of the penis, between the two sides, then it is uncertain which side will be affected. The situation of the glands of the groin is not always the same, and therefore the course of the absorbent vessels will vary accordingly. I have seen a venereal bubo, which arose from a chancre on the penis, a considerable way down the thigh ; on the contrary, I have seen it often as high as the lower part of the belly, before Poupart's ligament and sometimes near the pubes, all of which three situations may lead to some variations in the method of cure; therefore it may be proper to attend to them. As the disease most commonly arises from copulation, the situation of buboes is generally in the groin; but as no part of the body under certain circumstances, is exempt from this disease, we find the nearest external glands between the part of absorption and the heart, everywhere in the body share the same fate with those of the groin, especially if external. CHAPTER II.

OF BUBOES IN WOMEN. The same diseases in the absorbents, in consequence of the absorption of the venereal matter, take place in this sex as well as in men. 1 never saw but one case where the absorbent vessels were diseased ; but this is nearly in the same proportion as in men, when I consider the proportion the number of the one sex bears to that of the other who apply to me for a cure of the venereal disease in any form. The case was a gonorrhoea, with violent itching and soreness when the patient sat or walked, but she had very little pain in making water. When I examined the parts I could see no difference between them and sound parts, excepting that the left labium was swelled, or fuller than the other, and a hard cord passed from the centre of that labium upwards to the os pubis, and passed on to the groin of the same side, and was lost in a gland as hio-h as Poupart's ligament. It was not to be felt but by pressing the parts with some force, and it gave considerable pain upon pressure. 220 HUNTER ON THE VENEREAL DISEASE. The swelling of the labium appeared to be somewhat similar to the swelling of the prepuce in similar cases in men, so that they would appear to arise from the same cause. One would naturally suppose that what has been said of this complaint in the lymphatic glands in men, would be wholly applicable to women, and also that nothing peculiar to women could take place; but the seat of absorption is more extensive in this sex, and the course of some of the absorbents is also different, from whence there are three situations of buboes in women, two of which are totally different from those in men, and these I suspect to be in the absorbents. The third situation of buboes in this sex is similar to that in men, and therefore they maybe divided into three, as in men. When buboes arise in women where there is no chancre, it is more difficult to know whether they are venereal or not than in men; for when they arise in men without any local complaint it is known that no such complaint exists, and therefore the bubo cannot be venereal, excepting by immediate absorption; but in women it is often difficult to know whether there be any infection present or not; and therefore in order to ascertain the nature of the bubo attention must be paid to its manner of coming on, progress, and other circumstances. When chancres are situated forward, near to the meatus urinarius, nymphae, clitoris, labia, or mons Veneris, then we find that the matter absorbed is carried along one or both of the round ligaments, and the buboes are formed in those ligaments just before they enter the abdomen, without, I believe, ever going further. These buboes I suspect not to be glandular, but inflamed absorbents; and if so, it strengthens the idea that it is only an external part that can be affected in this way. When the chancres are situated far back, near the perinaeum, or in it, the matter absorbed is carried forwards along the an'ole between the labium and the thigh to the glands in the groin; a&nd often in this course there are formed small buboes in the absorbents similar to those on the penis in men; and when the effects of the poison do not rest here, it often produces a bubo in the eroin, as in men. & CHAPTER III.

OF the inflammation of buboes, and the marks that distinguish them from other swellings of the glands.

The bubo commonly begins with a sense of pain, which leads the patient to examine the part, where a small L!d tumour is to OF THE INFLAMMATION OF BUBOES, ETC. 221 be felt.* This increases like every other in inflammation that has a tendency to suppuration; and, if" not prevented, goes on to suppuration and ulceration, the matter coming fast to the skin. But we find cases, where they are slow in their progress, which I suspect either arises from the inflammatory process being kept back by mercury or other means, or being retarded by a scrofulous tendency, such a disposition in the parts not so readily admitting the true venereal action. At first the inflammation is confined to the gland, which is moveable in the cellular membrane; but as it increases in size, or as the inflammation, and more especially the suppuration, advances, which in all cases produce rather a common than a specific effect, the specific distance is exceeded: the surrounding cellular membrane becomes more inflamed, and the tumor is more diffused. Some buboes become erysipelatous, by which means they are rendered more diffused and cedematous, and do not readily suppurate, a circumstance often attending the erysipelatous inflammation. To ascertain what a disease is, is the first step in the cure; and when two or more causes produce similar effects, great attention is necessary to distinguish one effect from another, so as to come at the true cause of each. The glands of the groin, from their situation, are liable to suspicion, "for besides being subject to the common diseases, they become exposed to others, by allowing whatever is absorbed to pass through them; and as the route of the venereal poison to the constitution is principally through them, and being oftener ill from this cause than any other, they often are suspected of this disease without foundation. To distinguish with certainty the true venereal bubo from swellings of those glands arising from other causes, may be very difficult. We must, however, examine all circumstances, to ascertain in what the bubo differs from the common diseases of those glands, whether in the groin or elsewhere, in which examination the apparent causes are not to be neglected. I have already given the character of the venereal bubo in general terms; but I shall now be more particular, as the two are to be contrasted. The true venereal bubo, in consequence of chancre, is most commonly confined to one gland. It keeps nearly its specific distance till suppuration has taken place, and then becomes more diffused.! It is rapid in its progress from inflammation to suppu-

* It must be remarked here, that whenever a person has either a gonorrhoea or a chancre, he becomes apprehensive of a bubo ; and as there are in the gonorrhoea, and sometimes in the chancre, sympathetic sensations in ^ near the groin, rhev are suspected by the patient to be beginning buboes, and the hand is mmSiSy applied to ihe part; and if he feels one of the glands although not in The least increased, the suspicions are confirmed, from a belief that he has no

^fltCvbe'obSved here, that the glands and surrounding parts being dissimilar"inflammation does not so readily become diffused as when it takes place in a common part. 222 HUNTER ON THE VENEREAL DISEASE. ration and ulceration. The suppuration is commonly large for the size of the gland, and but one abscess. The pain is very acute. The colour of the skin which the inflammation attacks is of a florid red. It may be observed, that the buboes in consequence of the first mode of absorption, viz. where no local disease has been produced, will always be attended with a greater uncertainty of the nature of the disease than those attended or preceded by a disease in the penis, because a simple inflammation and suppuration of these glands are not sufficient to mark it to be veneral; but as we always have this disease in view when the glands of the groin are the seat of the disease, the patient runs but little risk of not being cured, if it should be venereal; but I am afraid that patients have often undergone a mercurial course when there has been no occasion for it. It will perhaps be difficult to find out the specific difference in the diseases themselves; but I think that such buboes as arise without any visible cause are of two kinds; one similar to those arising from chancres or gonorrhoea; that is, inflaming and suppurating briskly. Ihese I have always suspected to be venereal; for although there is no proof of their being so, yet from these circumstances there is a strong presumption that they are. The second are generally preceded and attended with slight fever or the common symptoms of a cold, and they are generally indolent and slow in their progress. If they are more quick than ordinary, they become more diffused than the venereal, and may not be confined to one gland. When very slow they give but little sensation, but when more quick, the sensation is more acute, though not so sharp as in those that are venereal; and most commonly they do not suppurate, but often become stationary. When they do su'ppurate it is slowly, and often in more glands than one, the inflammation being more diffused, and commonly small in proportion to the swelling. The matter comes slowly to the skin, not attended with much pain, and the colour is different from that of the other being

a^l^ Now let us see what other causes there are for the swelling of these glands besides venereal infection, to which I have a crfbed one of the modes of swelling; for there must be other cauSe to account for the other modes of it. causes to The first thing to be attended to is, whether or not there are anv

some inflammation E ° Tin i.t A f"*! ".n,d ai'ended wi,h

and an ap„e ^^^t^SS^S^ OF THE INFLAMMATION OF BUBOES, ETC. 223

slow in their cure, and do not seem to be affected by mercury, even when very early applied. A gentleman had all the symptoms of a slight fever; the pulse a little quick and hard, loss of appetite, and of course loss of flesh; a listlessness, and a sallow look. While he was in this state a swelling took place in the glands of one of the groins. He immediately sent for me, because he imagined it to be venereal. From the history of the case, I gave it as my firm opinion it was not; in this he had not much faith. The swellings were not very painful, and, after having acquired a considerable size, they became stationary. To please him, I gave him a box of mercurial ointment, to be rubbed on the leg and thigh only of the side affected, that it might have a sufficient local effect, and as little go into the constitution as possible; but it did not appear to be of any service to the swellings in the groin, they remaining stationary, and almost without pain. His friends became uneasy, and sent their surgeons to him, who, without knowing he was my patient, and of course without knowing my opinion, imagined that the disease was venereal, and talked of giving mercury. With respect to the cure, I thought he should go to the sea and bathe. Allowing the chance of the disease being venereal or not venereal to be equal, I reasoned upon that ground. His present want of health could not be supposed to arise from any venereal cause, as it was prior to the swelling in the groin; and therefore though the swelling might be venereal, he was not at present in a condition to take mercury, as a sufficient quantity of that medicine, for the cure, might kill him; and if it should not be venereal, that still a greater quantity of mercury must be given than what was necessary if it were venereal; because its not giving way readily would naturally make the surgeon push the mercury further; and, besides this disagreeable circumstance, the disease in the groin might be rendered more difficult of cure. But by going to the sea his constitution would be restored; and if the disease in the groin proved to be venereal, he would be in a proper condition to go through a mercurial course, and by that means get rid of both diseases by the two methods. But if I should be right in my opinion, that there was nothing venereal in the case, then he would probably get well by the sea-bathing. These arguments had the desired effect: he went directly to the sea, and began to recover almost immediately. About a fortnight after, a small suppuration took place in one of the glands. I directed that a poultice should be made with sea-water, and applied; and, in case of the breaking of the abscess, that it should not be further opened, but poulticed till healed. In six weeks he came back perfectly recovered in every respect. The above-mentioned appearance, with the constitutional affections I have seen take place when there were chancres, and I have been'puzzled to determine whether it was sympathetic, from a derangement of the constitution, or from the absorption of matter. I have long suspected a mixed case, and I am now certain that 224 HUNTER ON THE VENEREAL DISEASE. such exists. I have seen cases where the venereal matter, like a cold or fever, has only irritated the glands to disease, producing in them scrofula, to which they were predisposed. In such cases the swellings commonly arise slowly, give but little pain, and seem to be rather hastened in their progress if mercury is given to destroy the venereal disposition. Some come to suppuration while under this resolving course, and others, which probably had a venereal taint at first, become so indolent that mercury has no effect upon them, and in the end get well either of themselves or by other means, which, I imagine, may have induced some to think that buboes are never venereal. Such cases require great attention, that we may be able to determine them properly; and I believe this requires in many cases so nice a judgment that we shall be often liable to mistakes. Buboes are undoubtedly local complaints, as has been explained. How far the lymphatic glands are to be considered as guards against the further progress of this or any other disease caught by absorption, is not easily determined. We must, however, allow that they cannot prevent the poison from entering the constitution in cases where it produces buboes, for whenever it affects these glands in its course, it produces the same disease in them which is capable of furnishing the constitution with an increased quantity of the same kind of poison. CHAPTER IV.

general reflections on the cure of buboes.

From what has been offered on the history of buboes, it will be needless here to enter into a discussion of the opinion of their beinoa deposit from the constitution, and of the conclusion drawn from this opinion, that they ought not to be dispersed; for according to this theory, to disperse them would be to throw the venereal matter upon the constitution. But if this were really the case, then there would be no occasion for the use of mercury, provided that the bubo be allowed to proceed, as it would prove its own cure • but even those who were of this opinion were not satisfied with the cure which they supposed Nature had pointed out, but eave mercury and in very large quantities. From the same histoFy of a bubo I have also endeavoured to show that there are several buboes which are not in the least venereal, but scrofulous; and that there are also buboes which appear to be only in part venereal, or perhaps only a gland disposed to scrofula, brought into action bv die venereal irritation, similar to what happen! often from the matter of the.smallpox ,n inoculation. Therefore, prior to he speaking of the method of cure the true venereal bubo is to be ON THE CURE OF BUBOES. 225 distinguished from others, if possible. When it is well ascertained to be venereal, resolution is certainly to be attempted, if the bubo be in a state of inflammation only. The propriety of the attempt depends upon the progress which the disease has made. If it be very large, and suppuration appears to be near at hand, it is probable that resolution cannot be effected; and if suppuration has taken place, I should very much doubt the probability of success, and an attempt might now possibly only retard the suppuration, and protract the cure. The resolution of these inflammations depends principally upon mercury, and almost absolutely upon the quantity that can be made to pass through them; and the cure of them, if allowed to come to suppuration, depends upon the same circumstances. The quantity of mercury that can be made to pass through a bubo depends principally upon the quantity of external surface for absorption beyond the bubo. Mercury is to be applied in the most advantageous manner; that is, to those surfaces by an absorption from which it may pass through the diseased gland; for the disease there being destroyed, the constitution has less chance of being contaminated. The powers of mercury may often be increased from the manner in which it is applied. In the cure of buboes, it should always be made to pass into the constitution by the same way through which the habit received the poison; and, therefore, to effect this it must be applied to the mouths of those lymphatics which pass through the diseased part, and which will always be placed on a surface beyond the disease. But the situation of many buboes is such as not to have much surface beyond them, and thereby not to allow of a sufficient quantity of mercury being taken in in this way; as, for instance, those buboes on the body of the penis arising from chancres on the glans or prepuce. These two surfaces are not sufficient to take in the necessary quantity to cure those buboes in its passage through them; therefore whenever the first symptoms of a bubo appear, its situation is well to be considered, with a view to determine if there be a sufficient surface to effect a cure, without our having recourse to other means. It is first to be observed, whether the absorbent vessels on the body of the penis are affected, or the glands in the groin. If the disease be in the groin, it must be observed in which of the three situations of the bubo, before taken notice of, it is; whether on the upper part of the thigh and groin, on the lower part of the belly before Poupart's ligament, or near to the pubes. If they are on the body of the penis, this shows that the absorbents leading directly from the surface of absorption are themselves diseased. If in the groin, and on the upper part of the thigh, or perhaps a little lower down than what is commonly called the groin, then we may sunnose it is in the glands common to the penis and thigh. If high im or on the lower part of the belly, before Poupart's ligament, 1' 20* 226 HUNTER ON THE VENEREAL DISEASE. then it is to be supposed that these absorbents that arise from about the groin, lower part of the belly and pubes, pass through the bubo; and if far forwards, then it is most probable that only the absorbents of the penis and skin about the pubes pass that way. The knowledge of these situations is very necessary for the application of mercury for the cure by resolution, and for the cure after suppuration has taken place. The propriety of this practice must appear at once when we consider that the medicine cannot pass to the common circulation without going through the diseased parts; and it must promote the cure in its passage through them; while at the same time it prevents the matter which has already passed, and is still continuing to pass, into the constitution from acting there, so that the bubo is cured and the constitution preserved. But this practice alone is not always sufficient; there are many cases in which mercury by itself cannot cure. Mercury can only cure the specific disposition of the inflammation; and we know that this disease is often attended with other kinds of inflammation besides the venereal. Sometimes the common inflammation is carried to a great height; at other times the inflammation is erysipelatous, and, 1 suspect, often scrofulous. We must therefore have recourse to other methods. Where the inflammation rises very high, bleeding, purging, and fomenting are generally recommended. These will certainly lessen the active power o'f the vessels, and render the inflammation more languid; but they can never lessen the specific effects of this poison, which were the first cause, and are still in some degree the support of the inflammation. Their effects are only secondary, and if they reduce the inflammation within the bounds of the specific, it is all the service they can perform. If the inflammation be of the erysipelatous kind, perhaps bark is the best medicine that can be given; or if it be suspected to be scrofulous, hemlock, and poultices made with sea-water, may be of service. Vomits have been of service in resolving buboes, even after matter has been formed in them, and after they have been nearly ready to burst; this acts upon the principle of one irritation destroying another; and sickness and the act of vomiting perhaps give a disposition for absorption. A remarkable instance of this kind happened in an officer who had a bubo at Lisbon. It came to fair suppuration and was almost ready to burst. The skin «•« thin an inflamed, and a plain fluctuation felt. I imended o open but as he was going on board a ship for England on the dav following I thought it better to defer it" Whence wen"on board he set sail immediately, and the wind blew so very ha dVt not bin a could be done for some days, all which time he wasvery ,7ck and vomited a good deal; when the sickness went off he fo7nd the bubo had disappeared and it never afterwards appeared When he came to England he went through a regular course of mercury ON THE CURE OF BUBOES. 227 § 1. Of Resolution of the Inflammation of the Absorbents on the Penis. The surface beyond the seat of the disease in this case, that is, all that part of the penis before the bubo, is not large enough to take in a quantity of mercury sufficient to prevent the effects of absorption, and therefore recourse is to be had to other means; yet this application should by no means be neglected, and this surface, small as it is, should be constantly covered with mercurial ointment, which will assist in the cure of the local disease. It may be disputed whether any medicine can pass through diseased lymphatics, so as to have any effect upon them, but I judge from experience that it certainly can. As this surface is too small, and as it is necessary that a larger quantity should be taken in, it becomes proper to give it either by the mouth, or by friction on some larger surface; this is necessary, to prevent the lues venerea, as well as to cure the parts themselves. The quantity cannot be determined; that must be left to the surgeon, who must be directed by the appearances of the original complaint, and the readiness with which the disease gives way. The same method is to be followed in women; but as there is a larger surface in this sex more mercury may possibly be absorbed; and there should be a constant application of ointment to the inside and outside of the labia.

§ 2. Of the Resolution of Buboes in the Groin.

The inflammation of the glands is to be treated exactly upon the same principle with the other; but we have in general a larger surface of absorption, so that we can make a greater quantity of mercury pass through the diseased parts. It will be proper to apply the mercury according to the situation of the inflamed gland. If the bubo be in the groin, according to our first situation, then it is necessary to rub the mercurial ointment upon the thigh. This surface will in general absorb as much mercury as will" be sufficient to resolve the bubo, and to preserve the constitution from being contaminated by the poison that may get into it; but if resolution does not readily take place, then we may increase the surface of friction, by rubbing the ointment upon the leg. • • i But if the bubo be on the lower part of the belly, that is, in the second situation, then the ointment should be rubbed also upon the penis, scrotum, and belly; and the same if the bubo should be still forwards ; for probably those glands receive the lymphatics from all the surfaces mentioned, as well as from the thigh and leg. The length of time for continuing the frictions must be determined by circumstances. If the bubo gives way, they must be continued till it has entirely subsided, and perhaps longer, on account of the cause of it, a chancre, which may not yield so soon as the 228 HUNTER ON THE VENEREAL DISEASE. bubo. If it still goes on to suppuration, the frictions may or may not be continued, for I do not know for certain if anything is to be gained by their continuance in this state. The quantity here recommended may affect the mouth ; and this effect must also be regulated according to circumstances.

§ 3. Of the Resolution of Buboes in Women.

When treating on the seat of buboes in women, I observed that two situations were peculiar to them, the others similar to those in men. In the first and second situations, especially the first, the surface of absorption, beyond the bubo, is by much too small to be depended upon for receiving a sufficient quantity of mercury to produce resolution ; but in the second, that is, between the labia and thigh, the mercury may be rubbed in all about the anus and buttock, as all the absorbents of those parts probably pass that way; we know at least that they do not pass into the pelvis by the anus, but go by the groin. Other means of introducing mercury must be recurred to, as is recommended in the case of men ; but still it will be proper to rub in on those surfaces as much as possibly. In the situations common to both sexes we have a larger field; yet as they are divisible into three, the same observations hold good, and a similar mode of practice is to be followed in women as in men.

§ 4. Of Buboes in other Parts.

As venereal buboes arise from other modes of application of the poison besides coition, they are to be found in different parts of the body, but more frequently in the hands. They arise in the arm-pit from wounds in the hands or fingers being contaminated by venereal matter and reduced to a chancre. In such cases it becomes necessary that the ointment should be rubbed on the arm and forearm; but this surface may not be sufficient, therefore we must apply it in another way, or to other parts, to produce its effects upon the constitution. l enccis I have seen a true venereal chancre on the middle of the lower hp produce a bubo on each side of the neck under the lower iaw just upon the maxillary gland. By applying strong mercurial £ ment to the under lip, chin, and swellings, they have been resold.

§ 5. Of the Quantity of Mercury necessary for the Resolution of a Bubo.

be taken to stop short of cerTn eflbL ,,i„ H ' bu,Car0 must it be in the firs, si.na.ton, anT^a^o' flteTe"oft ,f " ON THE CURE OF BUBOES. 229 dram of mercurial ointment, made of equal parts of quicksilver and hog's lard, every night, and the mouth does not become sore, or at most only tender, then it will be sufficient to pursue this course till the gland is reduced to its natural size; and this probably will be a good security for the constitution, provided that the chancre, which may have been the- cause of the bubo, heals at the same time. If the mouth is not affected in six or eight days, and the gland does not readily resolve, then two scruples or a dram may be applied every night; and if there be no amendment, then more must be rubbed in; in short, if the reduction is obstinate the mercury must be pushed as far as can be done without a salivation. If there be a bubo on each side, then there cannot be so much mercury applied locally to each; for the constitution most probably could not bear double the quantity which is necessary for the resolution of one. But in such cases we must not so much attend to the soreness of the mouth as when there is but one; however, we must allow the buboes to go on to suppuration, rather than affect the constitution too much by the quantity of mercury; and therefore when there are two buboes they are more likely to suppurate than where there is only one. In the second and third situation of buboes, if we find that most probably a sufficient quantity of mercury does not pass through them for their resolution, it may be continued to be thrown in by the leg and thigh to act upon the constitution, as has been already observed. The quantity admitted in this way must be greater than what would be necessary if the whole could be made to pass through the bubo. The mouth must be affected, and that in proportion to the state and progress of the bubo. The method of resolving buboes occurred to me at Belleisle, in the year 1761, where I had good opportunities of trying it upon the soldiers; and I can say with truth that only three buboes have suppurated under my care since that time, and two of these were in one person, where a small quantity of mercury had considerable effects on the constitution, and therefore a sufficient quantity could not be sent through the two groins for their resolution ; but in both cases the suppurations were small in comparison to what they threatened to be. Many buboes, after every attempt, remain swelled without either coming to resolution or suppuration, but rather become hard and scirrhous. Such, I apprehend, were either scrofulous at first, or became so when the venereal disposition was removed. The cure of them should be attempted by hemlock, sea-water poultices, and sea-bathing, as will be further taken notice of.

§ 6. Of the Treatment of Buboes when they suppurate.

After every known method has been used, buboes cannot in all cases be resolved, but come to suppuration. They then become more an object of surgery, and are to be treated in some respects like 230 HUNTER ON THE VENEREAL DISEASE. any other abscess. If it be thought proper to open a bubo, it should be allowed to go on thinning the parts as much as possible. The great advantage arising from this is, that these parts, having become very thin, lose the disposition to heal, which gives the bottom of the abscess a better chance of healing along with the superficial parts; by this means too a large opening is avoided,and the different modes made use of for keeping the skin from healing till the bottom is healed become unnecessary. It may admit of dispute whether the application of mercury should be continued or not through the whole suppuration. I should be inclined to continue it, but in a smaller quantity; for although the parts cannot set about a cure till opened, yet fdo imagine that they may be better disposed to it; and I think that I have seen cases where suppuration has taken place, although under the above mentioned practice, that were very large in their inflammation, but very small in their suppuration, which I imputed to the patient's having taken mercury in the before-mentioned way, both before and while suppuration was going on. It has been disputed more in this kind of abscess than in others whether it should be opened or allowed to burst of itself; and likewise whether the opening should be made by incision or caustic. Ihere appears to be nothing in a venereal abscess different from any other to recommend one practice more than another. The surgeon should in some degree be guided by the patient. Some patients are afraid of caustics, others have a horror of cutting instruments; but when it is left wholly to the surgeon, and the bubS is but small, I suppose a slit with a lancet will be sufficient; in this way no skin is lost. But when a bubo is very large, in which case mere is a large quantity of loose skin, perhaps the caustic will answer better, both on account of its destroying some skin, and latUSVh^ destruction is attended with less inflammation than

The bes ttVil01810"; Jf d°ne by a C3UStic' the laPis sePtic»s is t mav £ Hiffl u f0t necessary ,to °Pe« every bubo, and perhaps seS o6r nettaiy. ^ °Ut ^^ ^ °^ ^ be of The bubo is to be dressed afterwards according to the nature of

to be attacked ,vi.h mercury! eitherbfaonlv?^ ?, "7* T "

of^f^ passing through the part. disease in its

otTer. 0TeheXestedwIr0wS0tehSe W^lS^ff^ T ^^^ ^ ^ pain, and therefore he would have ?he other «„I ^ .^ him <*n.iderable would only be momentary. B,tit was „Zt°pe"eduw,tl1 a la™et, as ihe pain while there was no pain in the other deaden*/^ J8 soreness continued long, its business. ' deadened by the caustic, after it had done OF THE CONSEQUENCES OF BUBOES. 231 Mercury, in these cases, answers two purposes; it assists the external application to cure the buboes, and it prevents the effects of the constant absorption of the venereal matter from the sore. How far it is necessary to pursue the mercurial course with a view to prevention, it is not possible to determine; but it may be supposed that it is necessary to give the same quantity to prevent a disease that would cure one that has already taken place. It will be necessary to continue the course till the bubo is healed, or till it has for some time lost its venereal appearance; but it may be difficult to ascertain this last fact: therefore we must have recourse to experience, not theory, and continue the course in general till the whole is healed, and even longer, especially if the bubo heals very readily; for we find in many cases that the constitution shall be still tainted after all. However, some restrictions are here necessary; for I have already observed that it often happens that buboes assume other dispositions besides the venereal, which mercury cannot cure, but will even make worse. It is therefore very necessary to ascertain the distinction, which will be taken notice of. CHAPTER V.

OF SOME OF THE CONSEQUENCES OF BUBOES.

I formerly observed that the venereal disease is capable of bringing latent dispositions or susceptibilities into action. This is remarkably the case with buboes ; and I believe the disposition is more of the scrofulous kind than any other. Whether this arises from the buboes being formed in lymphatic glands or not is probably not easily determined. It sometimes happens that these sores, when losing or entirely deprived of the venereal disposition, form into a sore of another kind, and most probably of various kinds. How far it is a disease arising from a venereal taint and the effects of a mercurial course jointly is not certain; but most probably these two have some share in forming the disease. If this idea of it were just, it -would become a specific disease and be reducible to one method of cure; but I should suspect that either the constitution or the part hath some, if not the principal, share in it; that is, the parts fall into a peculiar disease independent of the constitutional disease or method of cure ; for if it arose out of the two first entirely, we might expect to meet with it oftener. So far as the constitution or the part has a share in forming this disease, it becomes more uncertain what the disease is, because it must in some degree partake of the constitution or nature of the part. Such diseases make the cure of the venereal affection much more 232 HUNTER ON THE VENEREAL DISEASE. uncertain, because when the sore becomes stationary, or the mercury begins to disagree, we are ready to suspect that the virus is gone; but this is not always the case: the virus is perhaps only less powerful than the new-formed disease, and, as it were, lies dormant, or ceases to act; and when the other becomes weaker, the venereal influence begins to show itself again. The proper treatment in such cases is to attack the predominant disease; but still the difficulty is to find out the disease, and to know when it is or is not venereal. The following case explains this difficulty very well. A gentleman had a very large venereal bubo, which was opened. He took a great deai of mercury for about two months; but, I suspect, not in sufficient doses, which produced a mercurial habit. The bubo had no disposition to heal, and I was consulted. From the account he gave me, I suspected that he had then too much of a mercurial habit to receive at this time any further good from that medicine. I therefore advised him to use a good nourishing diet for near a month; after that I put him upon a brisk mercurial course by friction; and the parts put on a better appearance. This course he continued for near two months, and then the sore, although much mended, began to be stationary. I did now conceive that the venereal action was destroyed, and therefore immediately left off the mercurial course, and put him upon a milk diet, and sent him into the country. But not gaining much ground, he had a strong decoction of the sarsaparilla with mezereon given him, which, although continued for above a month, produced'little or no effect. I also gave him the cicuta as much as he could bear, with the bark almost the whole time, without effect: new sinuses formed, which were opened, and the sore became extremely irritable, with thickened lips. The dressings were poultices made with the juice of hemlock, sea-water, opium, and a gentle solution of lunar caustic; but nothing seemed to affect it. I suspected scrofula, and therefore proposed he should bathe in the sea • but this then could not be done These different treatments, after mercury had been left off, took up about four months without the least benefit. Being doubtful whether there might not be still something venereal in the sore especially as appearances were growing worse, and it was now four months since he had taken any mercury I was inclined to try it once more, and sent him two portions of ointment, half an ounce each, to rub in in two nights. He had caught a little cold, and therefore did not rub in the mercury the wo evenings as ordered; and called upon me the third da?and told me he was much better. The sore now became easy the watery or transparent inflammation began to subZl S'

.itt.e. .neightortenflaysrsltfl'con, aSo IhV " o^ of us former s,zc. and had all the appearance of a healint soT Qutere: What eonclnstons should be drawn from this°c1i°e5 I OF THE CONSEQUENCES OF BUBOES. 233 think the following: that the virus may be gone, although the sore may have no disposition to heal; therefore we are not to look upon the not healing of a bubo as a sign of the presence of the original disease. Secondly, that the sarsaparilla, mezereon, cicuta, and the bark will not succeed in all such cases: and thirdly, that some of these diseases are capable of wearing out the unhealty disposition of themselves, and that we should not be too ready to attribute cures to our treatment; for if the mercury had been rubbed in, and the same effects had still taken place, I should then have certainly pursued the mercury with vigour, and attributed the cure to it: but I should not have rested here; I should have related the case, as an instance of the disease continuing after repeated courses of mercury, and should have contended that it is necessary in such cases, where the mercury appears to lose its power, and even do harm, to wait, and season the constitution to strength, and the loss of the mercurial habit; and that even four months are sometimes necessary for this purpose, after which we must begin again to give mercury. A gentleman had a common gonorrhoea, which was severe. I gave him an injection of a grain of corrosive sublimate in eight ounces of water, with a few mercurial pills. After having continued the injection for ten or twelve days, without any visible benefit, I gave it as my opinion that it would be of no service to continue it any longer, and therefore desired he would be quiet for a little time. About this time a swelling in each groin took place, and supposing them to be venereal, I ordered mercurial ointment to be rubbed into both the legs and thighs, to resolve them if possible. He appeared to be less uneasy about the buboes than he was about the gonorrhoea, but I told him that the cure of that complaint would he insensibly involved in the resolution of the buboes. I spoke too confidently of my power with respect to the resolution of the buboes, for they both suppurated, although the suppuration was small in comparison to the magnitude of the buboes when they first inflamed. The frictions were left off. While we were attempting to resolve the buboes he got well of the gonorrhoea. The skin covering the buboes became thin; they were both opened, one with a caustic the other with a lancet; he then was ordered to rub in mercury again on the thighs and legs for their cure. They began soon to look well, and to close fast; but when about half healed they became stationary. I suspected that a new disease was forming. On continuing the frictions a little longer they began to inflame and swell anew, and a suppuration took place about half an inch above each of the first suppurations, which broke into the first. I left off the mercury immediately upon their inflaming, and said that now a new disease had formed. I ordered poultices made with sea-water to be applied, and also a decoction of sarsaparilla to be taken ; but this appeared not to be sufficient for the cure of this new disease. I then ordered him to go into the tepid sea-bath every evening, the heat of the 234 HUNTER ON THE VENEREAL DISEASE. water to be about ninety degrees. By the time he had been in the bath four times the inflammation and swelling had very much abated, and the first sores, or original buboes, were beginning to heal. He went on with the bathing every evening for about three weeks, when the sores rather began to look worse; I then suspected that the venereal disposition was become predominant, and I ordered the friction as before. In about a fortnight the first buboes healed, but the second suppurations were not yet healed; then I supposed it to be entirely the new-formed disease, and he went into the country, where I desired he might go into the open sea every day, as he then could have an opportunity, which he did, and got perfectly well, and has continued so. This case plainly shows that there was another disposition formed besides the venereal, which was put into action by the venereal irritation. I have seen some buboes most exceedingly painful and tender to almost everything that touched them, and the more mild that the dressings were, the more painful the parts became. In some the skin seems only to admit the disease, ulceration going on in the surrounding skin, while a new skin forms in the centre, and keeps pace with the ulceration, forming an irregular sore like a worm-eaten groove all round. This, like the erysipelatous inflammation, as also some others, appears to have only the power of contaminating the parts that have not yet come into action; and those that have already taken it seem to lose the diseased disposition, and heal readily. In some they spread to an amazing extent, as the following case shows, the circumstances of which are very remarkable. A young gentleman, aged eighteen years, in consequence of a venereal infection, had two buboes, which were both opened They were treated m the usual manner, and at first put on a favourable appearance ; but when they were nearly healed they began to ulcerate at their edges and spread in all directions, rising above the pubes almost to the navel, and descending upon each thieh His nights became restless, and his general health was affected: A great variety of medicines were tried, particularly mercury in different forms, with little or no effect. Extract of"hemlock d d more good than anything else, and was taken in unusual quantities An ounce was swallowed in the course of the day for some time" which was afterwards increased to an ounce and a half" two ounces' and even two ounces and a half. It produced indistincUisfon and blindness, loss of the voice, falling of the Inwpr^V * palsy of the extremities, and oncf or twi J»Tn JT* * te.mPorar? notwithstanding he was almo? evervZhi °f sensatl0n' and of complete intoxication fr^ntLh!Z tiin a State'as il were' suffer, but, on the coT^ did not

wereliheralUiven, ^^?£*g ^e,s P,,l OF THE LUES VENEREA. 235 had to the hemlock from time to time. A great many different kinds of dressings were made trial of, none of which were found to exceed dry lint. The ulcers were nearly all healed, after having tormented him upwards of three years, when committing some irregularities in diet, and the sores getting worse, he returned to the extract of hemlock, which he had for some time laid aside, and of himself swallowed in the course of the morning ten drams. This quantity was only the half of what he had formerly taken in twentyfour hours, but his constitution had been at that time gradually habituated to the medicine. The ten drams produced great restlessness and anxiety; he dropt insensible from his chair, fell into convulsions, and expired in two hours. To return to the cure of buboes: where they only become stationary, and appear to have but little disposition to spread (which is most common), and where perhaps a sinus or two may be found running into them from some other gland, I have often seen them give way to hemlock sooner than to anything I am acquainted with, especially if joined to the bark. If the hemlock is applied both internally and externally it answers better. Sarsaparilla is often of singular service here, as well as in other cases arising seemingly from the same cause ; and I have seen seabathing of great service, as also sea-water poultice. At the Lock Hospital they use gold-refiners' water as an application, which is of service in some cases. Dr. Fordyce recom.- mends the juice of oranges to be drunk in large quantities, which I have seen good effects from in some cases. The mezereon is in some instances of singular use. PART VI. CHAPTER I.

OF THE LUES VENEREA. Thf lues venerea, I have already observed, arises in consequence of the ooisonous matter being absorbed and carried into the common circulaCn This form of the disease, which I have called the 236 HUNTER ON THE VENEREAL DISEASE. constitutional,* would appear to be much more complicated, both in the different ways in which it may be caught, and in its effects when caught, than either a gonorrhoea or chancre. It generally arises from the local complaints before taken notice of, the matter being absorbed and carried into the constitution. The matter, however, appears to be capable of being taken into the constitution by simple application, without first having produced either of the before-mentioned local effects, as I observed in treating of the formation of the bubo; but this seems to be only when it is applied to some particular parts of our body, such as may be called a halfinternal surface, as the glans penis. I think it is not capable of being received by the absorbents of the sound skin ;f but this is matter only of opinion. It may likewise be received into the constitution by being applied to common ulcers, although not necessarily rendering these ulcers themselves venereal; also by wounds, as has been observed ; but, I believe, always previously producing ulceration in the wound. Many other modes of infection have been supposed, but, I believe, erroneously, such suppositions most probably having taken their rise from ignorance or deceit, two great sources of error in this disease. It is most likely that contamination takes place about the beginning of the local complaints, especially when that is a chancre; for there is in most cases less chance of its happening afterwards, because the patient commonly flies to medicine, which generally becomes a prevention of contamination. For if it could take place through the whole time of the cure, we should have the parts contaminated at different periods, coming into action at different times, each according to its stated time, although in similar parts both in their nature and other circumstances ; but as these similar parts do not vary much in the time of coming into action, it is reasonable to suppose that they were contaminated at or near the same time, and therefore that no contamination takes place in the time of the cure although we may suppose that the power of absorption is equally strong then as at any other time. In cases of contamination from a gonorrhoea, where no mercury has been taken, we might expect this irregularity in similar structures ; but as contamination so seldom takes place in this way we have not a chance of great variety from such; however it would be worth while to ascertain the matter, which from ™ many cases might be done. fcICrtL nsauy

* The term constitutional is, nerhan<? nnt ett;»ti„ - tutional disease strictly I wou dTderst'adthtVh^" ^ (°T ^ C°nSti' is acting in one way, as in feversof ah kinl !i^ h eLVery Part of the body the venereal poisonappears tob^onlv diffnspH thher7mPath^ or original; but as it were, to force cerlain pans 0f^ action is perfectly local, and takes Place in Si T the Venereal action, which of susceptibilities ; there are but f£wpa ?s &"' Parts In ^«>^ succession and a person may be constitutionallyXted in t^V '"^ the Same time 5 function may be perfect. Y ed m thls way> and yet almost every f Added : "At least I know no instance of h."—H„me. OF THE LUES VENEREA. 237 Without being very exact in ascertaining the different proportions in those who have the lues venerea originating from the three several modes above described, I think we may venture to say, from general practice or experience, that where one contracts it from the first cause, that is, where no local effects have been produced, a hundred have it from the second, or gonorrhoea ; and where one has it from the second, a hundred have it from the third, or chancre ; and perhaps not one in five hundred who have connexion with venereal women have it in the first way, and not one in a hundred have it from the second ; while not one in a hundred would escape it from the third, if the means of prevention were not made use of in the common method of cure of the chancre.

§ 1. Of the Nature of the Sores or Ulcers proceeding from the Lues Venerea. In consequence of the blood being contaminated with real venereal pus, it might naturally be supposed that the local effects arising therefrom would be the same with the original which produced them ; but from observation and experiment I have reason to believe that this is not so. In considering this subject, we may first observe that local effects, from the constitution, are all of one species, that is, ulcers, let the surface upon which they appear be what it will, whether the throat or common skin, which is not the case in the local application of the matter in gonorrhoea and chancre: for there I observed that it produced effects according to the nature of the surfaces. Now if the matter, when in the constitution, were to act upon the same specific principles with that which is applied, we should have gonorrhoeas when it attacks a canal, sores or chancres when it attacks other surfaces : but it has never been yet known to produce a gonorrhoea from the constitution, though this has indeed been suspected. For some gonorrhoeas, the origin of which has not been clear, and which have not easily given way to the common methods of cure, have been supposed to have arisen from the constitution. Whenever the disease affects the mouth and nose, it has always been looked upon as producing a true chancre ; yet even here I find that such ulcers in their first appearance are very different from chancres. The true chancre, I observed, produces considerable inflammation, which of course brings on quickly suppuration, attended often with a great deal of pain ; but the local effects, from the constitution, are slow in their progress, attended with little inflammation, and are seldom or never painful, except in particular parts. However, this sluggishness in the effects of the poison is more or less according to the nature of the parts which become diseased ; for when the tonsils, uvula, or nose are affected, its progress is rapid, and the sores have more of the chancre in their appearance than when it affects the skin ; yet I do not think that the inflammation is so great in them as in chancres that are ulcerating equally fast. 238 HUNTER ON THE VENEREAL DISEASE. It has been supposed that even all the secretions from the contaminated blood could be affected so as to produce a like poison in them; and as the parts of generation are thrown in the way of receiving it, when fresh contracted, so they still lie under the censure of having it returned upon them from the constitution. Hence it has been supposed that the testicles and vesicular seminales may be affected by the disease; that the semen may become venereal, may communicate the disease to others, and, after impregnation, may even grow into a pocky child. But all this is without foundation : otherwise, when a person has the lues venerea, no secreting surface could be free from the state of a gonorrhoea, nor could any sore be other than venereal. Contrary to all which, the secretions are the same as before; and if a sore is produced by any other means in a sound part, that sore is not venereal, nor the matter poisonous, although formed from the same blood. The saliva in the case of a mad dog, being a natural secretion rendered poisonous, may be brought as an argument in contradiction to this theory; yet it is easily accounted for, and might be produced rather as an argument in "support of it. In the dog there is an irritation peculiar to the hydrophobia in the salivary glands ; but the other and natural secretions of the same dog are not capable of giving this infection, because they are not susceptible of the same specific irritation. The breath and sweat are supposed to carry along with them contagion, the milk of the breast is supposed to be capable of containing venereal poison and of affecting the child who sucks it; but there are several reasons which overturn these opinions. First, we find that no secretion is affected by this poison, excepting where the secreting organs have been previously affected by venereal inflammation or irritation, or its specific mode of action. Again, if they were contaminated so as to produce matter similar to that of an ulcer in the throat, such matter would not be poisonous, nor possess a power of communicating the disease, as will be explained more fully hereafter. Further, true JhhTfh "T^ tV6n When taken intothe ^omach, does not affect Inthl t f°u °r constltution> bu* i« digested: as was evident in tne two following cases. A gentleman who had chancres which discharged largely, used

etThe limT -,S TH mi'k " t '?aCUp With some &»«• and'generaUy

locally in ,L stoJll^ZZtinS^ teen =« either

■nfllgnTatran„drhe^rct™^teritT',i,n "^ b°th the also a chordee, which v^Zl^^T I '^er OF THE LUES VENEREA. 239 to cool the parts, and keep them clean, he had a small bason of milk by the bedside, in which when the chordee was troublesome he got up and dipped or washed the penis. This operation he frequently repeated during the night. Under such complaints he allowed a young lady to sleep with him. Her custom was to have by the bedside a bason of tea to drink in the morning before she got up; but unfortunately for the lady, she drank one morning the milk instead of the tea. This was not known till she got up, which was five or six hours afterwards. I was sent for directly, and in the mean time she endeavoured to vomit, but could not. I ordered ipecacuanha, which proved slow in its operation. She vomited but it was more than eight hours after drinking the milk and water, and what came up was nothing but slime, mucus, or water, the milk being digested. I was attentive to what might follow; but nothing uncommon happened, at least for many months. It is also supposed that a foetus in the womb of a pocky mother may be infected by her. This I should doubt very much, both from what may be observed of the secretions, and from finding that even the matter from such constitutional inflammation is not capable of communicating the disease. However one can conceive the bare possibility of a child being affected in the womb of a pocky mother, not indeed from the disease of the mother, but from a part of the same matter which contaminated the mother, and was absorbed by her; and whether irritating her solids to action or not may possibly be conveyed to the child, pure as absorbed; and if so it may affect the child exactly in the same way it did or might have done the mother. This idea has been carried still further ; for it has been supposed that such a contaminated child could contaminate the breasts of a clean woman by sucking her; the possibility of which will be considered presently. We may observe that even the blood of a pocky person has no power of contaminating, and is not capable of giving the disease to another even by inoculation ; for if it were capable of irritating a sound sore to a venereal inflammation, no person that has this matter circulating, or has the lues venerea, could escape having a venereal sore whenever he is bled or receives a scratch with a pin, the part so wounded turning into a chancre. For if venereal matter may be on the point of the lancet, or on the point of the pin, the punctures must become chancres.

& 2. Of the Matter from Sores in the Lues Venerea compared with that from Chancres and Buboes.

When the matter has affected the constitution, it from thence wroduces many local effects on different parts of the body, which are in general a kind of inflammation, or at least an increased action occasioning a suppuration of its own kind. It is supposed that the matter produced in consequence of these inflammations, similar to the matter from a gonorrhoea or chancre, is also venereal 240 HUNTER ON THE VENEREAL DISEASE. and poisonous. This I believe till now has never been denied : and upon the first view of the subject, one would be inclined to suppose that it really should be venereal; for, first, the venereal matter is the cause: and again the same treatment cures both diseases; thus mercury cures both a chancre and a lues venerea ; however, this is no decisive proof, as mercury cures many diseases besides the venereal. On the other hand, there are many strong reasons for believing that the matter is not venereal. There is on? curious fact which shows it is not venereal, or if it be, that it is not capable of acting JhaSt°lettreSPfCtS °nuth,e Same h°dy or same state of constitution as that matter does which is produced from a chancre or gonorrhoea Thepus from these latter, when absorbed, generally produces a bubo' as has been described; but we never find I bubo from the absorption of matter from a pocky sore. Forinstance, when there is a venereal ulcer in the throat, we have no buboes in the glands of the neck when there are venereal sores on the arms, or even unpurating nodes on the ulna, there are no swellings of the gland? o? hf

Ts^P led5 o°aUgcoSUCh WiH tSke ^CG ,f fresh ™°™ - is applied to a common sore, on the arm, hand, or fingers No swelling takes place in the glands of the groin from either node*

is no absorption from such sores; but I think we have no grounds for such supposition. Its mode of irritation, or the acton ofhe parts affected, is very different from what happens in "he chancre gonorrhoea or bubo, being hardly attended with inflammatfen which in them is generally violent inflammation,

PockvifhnoMnS>Pffed. aV- Vonstitution truly and universally Ctm Te ™^^

^^ from the constitution, has not that power ' ' S

andAh™danbeca„d ^ZT^stn^JZ^ "IT" S ,0"«,ion. anew. He was taken into*S1 Geo,">sHos'i^fY " ' A^ a number of pocky sores- inH k „V„ tS "osP"al> affected with course I made th/fS^g^^n "1 tool""" * ^J?™1 one of the sores upon the point^f ThnJt » a """f m?tter fr°m wounds upon the back, where the ,1 ' "d made three sma11 and deep enough to drau bfood. ? madeTL^T1- ^ S°Und' other three with a clean lancet iLZ, Tld s,milar to the rangle; but all the wounds Supl^ZZ0^ ™kinZ a ^ad" afterwards. l' d none of '^m ever appeared This experiment I have rp->^taA same result. It showsMha Td0c1 T™ ^ °nCG' a"d with the ocally with the matter proceediE* f™ PT°U Cannct be affected lues venerea. But to see how fa Vc£Z ° ^ pr°duced b^ the of producing chancres on a pod y persoT?' m™VVMCaPabIe experiment. l^ypeison, I made the following OF THE LUES VENEREA. 241 A man, who had venereal blotches on many parts of his skin, was inoculated in sound parts with matter from a chancre, and also with matter from his own sores. The wounds inoculated with the matter from the chancres became chancres; but the others healed up. Here then was a venereal constitution capable of being affected locally with fresh venereal matter. This experiment I have likewise repeated more than once, and always with the same effect. I ordered a person, at St. George's Hospital to be inoculated with the matter taken from a well-marked venereal ulcer on the tonsil, and also with matter from a gonorrhoea, which produced the same effects as in the preceding experiment; that is, the matter from a gonorrhoea produced a chancre, but that from the tonsil had no effect. A woman, aged twenty-five, came into St. George's Hospital, August 21, 1782, with sores on her legs, and blotches over her body. Her husband gave her the venereal disease December 1781. Her symptoms then were a discharge from the vagina, and a small swelling of the glands of the groin, which were painful. She had taken some pills supposed to be mercurial. February 1782, about three months after being infected, the discharge stopped ; but the swelling, which had been gradually increasing ever since its first appearance, had now suppurated. She applied some ointment to it, which was brought to her by her husband, and in two months it got well, that is, in April 1782. After the bubo got well a discharge from the vagina came on, for which she took more of the same pills she had taken before. After this time blotches came out over her whole body; some about her legs, under her arms, and upon her nipples, ulcerated. Twins, which she brought forth at eight months, in March 1782, at the time the bubo was healing, had blotches upon them at their birth, and died soon after. Another girl, about two years old, whom she suckled, was also covered with blotches when she came to the hospital. To ascertain whether her secondary ulcers were infectious, that is, whether the matter of them would have the specific effects of venereal matter, she was inoculated with some matter from one of her own ulcers, and with some matter from a bubo of another person where mercury had not been used. This was done September 18, 1782. September 19, the puncture where she was inoculated with her own matter gave her pain three hours from the time of inoculation, and the day following inflamed a little. The other had not then inflamed at all. September 20, both the punctures had suppurated, and had the appearance of a small-pox pustule; they spread considerably, and were attended with much inflammation. That from her own matter healed with common poultices, and ointments without mercury ; but the other, although treated in a similar way, continued in the same state, attended with much pain and inflammation. September 22, the child was inoculated with some matter from 242 HUNTER ON THE VENEREAL DISEASE one of its own ulcers, and with some common pus. The punctures both inflamed in a small degree, but neither of them suppurated. The mother and the child went into the ward appropriated to salivation, October 21, 1782. The child took no mercury. It was supposed that its gums became a little sore; and the blotches *<* well. °

During the time that the mother was using mercury the ulcer from inoculation began to get well, and her venereal symptoms

veZlZt -rf ^ ShaH WG Sa^ t0 this case ? Were theybloPtches venereal > 1 here was every leading circumstance to make us think so, and our opinion was strengthened by the method of cure. If they were venereal, my opinion, that the constitutional appearances of the disease do not produce matter of the same species that produced them, is confirmed If they were not venereal, then wek absolute rule by which to judge in such cases.

in the mo«1h!I IT^f' &?d 3SSerted fr0m obs^vation, that ulcers "itutlnal dl °f dilIdl?n from a constitutional disease, which conhave nroiiS 5? '^ SUpP°Sed t0 be derived from the Pa^nt, hnd W id *}? STe disease uP°n the niPP'es of women who either by SV^ Vf ^ chiIdre« —e contaminated l^sv^rof^Tlu thT h3Ving the disease in form of a mes venei ea, of ^hich I have endeavoured to show the impossibilitv

wo rb^' ltuei'e P°SsibIe t0 c^taminate once in Ts way ^ would be possible to contaminate for ever * y'

opinion i^folmded^hr^r8' Up°5 ^t the before-mentioned overtnrn th« t\ ? ^een made with sufficient accuracy to know not R,7fh 1 made Whh S View t0 ascertain tbe truth, I thosl cases wh.VlT ° Tre a°CUrate inv^igation of some of theTapCSdWe^^^ would lead us into the^onsMeration of oTher dUasel tVT? lowing case mav le«spn on.- f^ti, ■ *u i • . aiseases. Ihe folbeen supposed 11 be ^enereaf hUt0ma °f SU°h aS have

distast'^Te^rnTstd be^LtrLl 'I?™ *th ^ ™> this child was born. The father was, ^ 'jf™ ^ears whe« mother a mild and mo SoZ^7 fond b«sband, and the venereal gonorrhoea two years"Sfore te°m ^ 7^ father had a years before the birth of the child Ah ?a™d' that is' fourtee« nage they had a child, and afLi, nine m1onths a*er marwere extremely healthy at birth anT.rill n T°nd' b°th of whom fell into a weakly state of health -nrl ■ Contl.nue so- The mother at the end of five montnsThe fourTTu^ °f her third ^hild

months, but was puny, weak, and had hlrdS ™as h?™ at seven It was immediately after birth attacked &y CUt,1C,e M'hen ^ attacked with a violent dysentery.

* [See observations on this snhi,w ■ m° SubJect in notes to Part VIL] OF THE LUES VENEREA. 243 It died in a few days, and was opened by me. The whole sKin was almost one excoriated surface. The intestines were much inflamed and thickened. With her fifth child, from great care, she went eight months, and it was now hoped that she might go the full time, and also that this child might be more healthy than the former. When she was delivered the child was very thin, but free from any visible disease. Some days after birth it became blistered in a vast number of places on its body, which blisters were filled with a kind of matter, and, when they broke, discharged a thinnish pus. The inside of the mouth was in the same condition. Bark was given to the nurse. Bark, in milk, was given to the child by the mouth, and it was fomented with a decoction of bark, but in about three weeks after birth it died. Some weeks after the death of the child the nurse's nipple, and the ring round the nipple, inflamed, and sores or ulcers were formed with a circumscribed base.* They were poulticed, but without benefit. She also complained of a sore throat, but the sensation she complained of was so low in the throat that no disease could be seen. A swelling took place in the glands of the armpit, but they did not suppurate. She applied to a physician, and according to the account which she gave, he pronounced that her disease was venereal, and that she had given suck to afoul child ; and he ordered ten boxes of mercurial ointment to be rubbed in on her legs and thighs, eight of which had been used when I saw her, and then her mouth was become extremely sore. These circumstances came to the ears of the family, and an alarm took place. The husband went from surgeon to surgeon, and from physician to physician, to learn if it were possible for him to have the disease for fourteen years, and never to have perceived a single symptom of it in all that time; or if it was possible he could get children with the disease now, when the two first were healthy. He also wanted to know if it was possible for his wife to have cauo-ht the disease from him under such circumstances, and also, if she could breed children with this disease, although she herself never had a single symptom of it. If we take all the above-mentioned circumstances as facts, the conclusion is, that it was impossible there could be anything venereal in the case; but as they could not be absolutely proved to be facts, there must remain a doubt in the mind, a something still to be proved. Now let us consider the result of the case. The nurse's mouth was become extremely sore from the mercury when I first saw her. I desired that Mr. Pott might see her along with me ; and it was the opinion of us both that the sores on the nipple and around it were not venereal; but it was alleged, that as she had taken mercury, their not having a venereal appearance now was owing

* She had but one breast that gave milk. 244 HUNTER ON THE VENEREAL DISEASE. to that cause. The bark was given, as also the sarsaparilla, but the sores did not heal, nor did they become worse; nor was the mouth better by leaving off the mercury. I ordered the hemlock, but that appeared to have no effect. In the mean time eruptions broke out on the skin. The skin of the hands and fingers peeled off; the nails of both fingers and toes separated, and sores formed about their roots, which were all supposed (by many) to be venereal. But some of them appearing while the constitution was full of mercury, and others disappearing without any further use of that medicine, I judged that they were* not venereal. We suspected that her mode of living was such as contributed greatly to the continuance of her first complaint, and gave rise to the new ones ; for she looked dejected and sallow. She was desired to go into a hospital, which she did. As soon as she got into a warm bed, and had good wholesome food, she began to mend, and in about five or six weeks she had become fat and almost well; the sore only about the root of the nail of the great toe had not healed ; but that appeared now to be owing to the root of the nail being detached, therefore acting as an extraneous body. She came out of the hospital before this toe had got well, and returning to her old poor mode of living, she had a return of the soreness in the mouth; however, she mended at last without the use of more mercury. This case I shall further consider when on diseases resembling the venereal. The following case will further prove that we often suspect complaints to be venereal when they really are not. A gentleman had for some time blotches on his skin. The face, arms, legs, and thighs were in many places covered with them, and they were in their different stages of violence. In this situation he applied to me, and I must own they had a very suspicious appearance. I asked him what he supposed these blotches were ; he said he supposed them to be venereal. I asked him when he had a recent venereal complaint; he told me not for above twelve months. I then asked him how long he had had the blotches; and the answer was, above six months. As this was a sufficient time for making observations upon them that might ascertain better than the mere appearance what they were, I asked him if any of the blotches that came first had disappeared in that time, and he said many; I desired to see where those had been, and on examination I found only a discoloured skin, common to the healing of superficial sores. I then declared to him that they were not venereal, for if they had arisen from that source none of them would have disappeared. He now informed me that he had been taking mercury; and this in- ZlTf °L fh mG 1° t3"6 r?C0Urse to ^ther inquiries; and I of he "r "tot wdP T ^ ^^ he W&S takinS mer<W' ™»7 of the hrat got u ell; The answer was, yes. And was the cure of those imputed to mercury ? The answer was again in he affir! mative. I then asked him if, while he was takinf the mercury which appeared to have cured some, those that^ow remained OF THE LUES VENEREA. 245 arose 1 Yes. My next question was, how long had he taken mercury? He said for six months. I then declared they were not, nor ever had been venereal. I asked him, what was now the opinion of his surgeon ? He said, that his opinion still was that they were venereal, and that he should go on with the mercury. I advised him to take no medicines whatever; to live well, avoiding excess, and to come to mc in three weeks ; which he did, and then he was perfectly well, only the skin was stained where the blotches had been. He now asked me what he was next to do ? I told him he might go to the sea and bathe for a month. This he did, and returned well and healthy, and has continued so.*

§ 3. Of the local Effects arising from the Constitution considered as critical.—Symptomatic Fever.

How far the eruptions or local effects of this disease, arising from the constitution, are an effort of nature to clear herself of this disease is not certain. I observed that a gonorrhoea might be produced by a general law in the animal economy, by which it endeavours to relieve itself of the irritation by producing a discharge; and that in chancres a breach is made in the solids for the same purpose, although this purpose is not answered in either; Nature not having a provision against this poison. But how far a similar attempt takes place in a lues venerea I do not know; and if it was upon the same principle, the same reason might be expected to be given why the constitution is not capable of relieving itself in the present instance that I gave when treating of the primary affections, because in this, as it was in the other, the matter formed might be supposed to be venereal; and therefore by being absorbed by the very surface which produced it as in a chancre, it might keep up the constitutional disease. If this were really the case, it would be very different from many other specific diseases; for the reason why many specific diseases cure themselves is that the irritation cannot last beyond a stated time; and also that in many the patient is never susceptible of the same disease a second time, as in the small-pox. If this was not the case, a person once having the small-pox would alwavs have them; for according to one supposition, that absorption of its own pus keeps up the disease; and according to another, that the irritation never wears itself out, the patient would either never be free, or have them repeated for ever; for his own matter would give the disease a second time, a third time, and so on.f But the venereal matter, when taken into the consti-

* Added • "The impropriety of giving mercury where the case is not venereal to indulge the wishes of the patient, is obvious, since it is confirming his suspicions injuring his constitution, and, when the medicine fails, making him believe himself incurable, since the symptoms have not yielded to the only medicine capable in his opinion of removing them."—Home. +' Thi* circumstance alone is a strong proof that people cannot have the smaiipol twice, at least at any distance of time between, if they had fair eruptions 246 HUNTER ON THE VENEREAL DISEASE. tution, produces an irritation which is capable of being continued independent of a continuance of absorption; and the constitution has no power of relief, therefore a lues venerea continues to increase. This circumstance is perhaps one of the best distinguishing marks of the lues venerea, for in its ulcers and blotches it is often imitated by other diseases, which not having this property will therefore heal and break out again in some other part. Diseases in which this happens show themselves not to be venereal. However, we are not to conclude, because they do not heal of themselves and give way only to mercury, that therefore they are not venereal, although this circumstance joined to others gives a strong suspicion of their being such. When the parts are contaminated by the venereal poison, we commonly find fever, restlessness, or want of sleep, and often headache ; but I believe that these symptoms are rather peculiar to the disease, when the second order of parts, the periosteum and bones, are affected, although they are sometimes found from the first. Do these symptoms arise from the local irritations affecting the constitution 1 And are they merely sympathetic? Whatever the immediate cause may be, they never go off till the local irritations are removed. This fever at first has much the appearance of the rheumatic fever; and after a time it partakes a good deal of the nature of the hectic. The symptoms often take place independent of, or unattended by, any local action; and when that is the case it becomes very uncertain what the disease is; for in cases not admitting of clear proof we must rest on the concurrence of circumstances. Many of these symptoms give way to mercury. This is probably the only concurring circumstance attending this complaint that is any proof of its being venereal.* It rather, however, appears to militate against this idea that, for the most part, a much smaller quantity is sufficient for the cure of such symptoms than what is necessary for the cure of local complaints. But if mercury always cured them, it would not be very material what they are called, "it is worthy of consideration, however, how far the venereal poison, when in the constitution, does or does not always produce local effects. That it in general does we are certain; but whether it is ever a cause of constitutional symptoms simply, such as loss of appetite, wasting, debility, want of sleep, and fever, at last becoming hectic, is uncertain; and it is also uncertain whether it is ever capable of producing local actions from irritations only, without an alteration of the structure of the parts irritated, as cough, secretion from the lungs, purging, headache, sickness, pain in different parts of the body, like rheumatic pains, but not from an alteration

the first time ; for if the constitution was not so altered as not to be susceptible of this irritation a second time, a person would have them immediately upon the going off of the first. * Here it is to be understood that the circumstance of a previous gonorrhoea or chancre is not to be considered as strong evidence. OF THE LUES VENEREA. 247 of the structure of the part taking place, as beginning nodes. If such effects take place, we must in such a case rely entirely on the history of the disease, and pronounce according to probability. Such complaints come oftener under the management of the physician than the surgeon, to whom I would recommend a particular attention to this. The fever in consequence of the venereal irritation, like most other fevers, deranges the constitution, which thereupon suffers agreeably to its natural tendency. It is capable of producing glandular swellings in many parts of the body, and probably many of the nodes that arise in the time of this fever may proceed from the fever; and similar to every such effect, from whatever cause, it does not partake of the disease which produced it, for it is not venereal: it only takes place in constitutions very susceptible of such action where the predisposing cause is strong, and probably at seasons most fitted to produce it, only waiting the immediate cause to put them into action. Such will and do go away of themselves when the predisposing cause ceases, such as season,

§ 4. Of the local and constitutional forms of the Disease never interfering with one another.

I observed, when treating of the gonorrhoea and chancre, that, when occurring in the same person, that one neither increases the symptoms nor retards the cure of the other. And it may also be observed that the chancre or gonorrhoea, and the constitutional form of the disease, meeting in the same person, do not interfere with each other, either in their symptoms or cure. To explain these effects more fully, let me observe, that if a man has a gonorrhoea, and a chancre appears some days after, the chancre does not either increase or diminish the gonorrhoea. Again, if a man has either a gonorrhoea, a chancre, or both, and a lues venerea ensue in consequence of either of these, neither the gonorrhoea nor chancre is affected by it. If a man has a lues venerea and gets either a gonorrhoea or chancre, or both, neither of them affects the lues venerea, nor are their symptoms the worse. Nor is the cure of either, singly, retarded by the presence of the other; for a gonorrhoea is as easily cured when there are chancres as when there are none, even although the chancres are not attempted to be cured; and a chancre may be cured locally independent of the gonorrhoea. Further, a gonorrhoea, chancre, or both, may be as easily cured when the constitution is poxed either by them, or previous to their appearance, as when the person is in perfect health ; but the chancre has this advantage, that the constitution cannot be cured without its being likewise cured. The gonorrhoea and chancre indeed so far influence one another as the one can be in some degree a cause of prevention of the other, as has been already observed; but I believe that this circumstance 248 HUNTER ON THE VENEREAL DISEASE. does not assist in the cure of either; yet I could conceive it might, each acting as a derivator to the other, without increasing its own specific mode of action.

§ 5. Of the supposed Termination of the Lues Venerea in other Diseases.

This disease seldom or never interferes with other disorders, or runs into, or terminates in any other, although it has been very much accused of doing so; for a termination of one disease in another, as I understand the expression, must always be a cure of the one terminated ; but the venereal disease never terminates till the proper remedy is applied, and therefore never can run into any other disease. That venereal complaints may be the cause of others I think is very probable. I have seen a chancre the immediate cause of an erysipelatous inflammation, but the venerea] malady did not terminate in the erysipelatous inflammation; for if it had, the chancre would have been cured: nor was the erysipelatous inflammation venereal; the chancre only acted here as a common irritator, independently of the specific quality of the disease as a cause. I have known a venereal bubo become a scrofulous sore as soon as the venereal poison was destroyed by mercury: this was not a venereal terminating in a scrofulous affection, for in such a view the scrofula must have cured the venereal. The venereal disease would seem only to partake of the nature of such disorders as the constitution was previously disposed to, and may excite into action the causes of these disorders. The same observation and mode of reasoning holds equally good with respect to other diseases. The common symptoms, however, of the lues venerea, though in some degree according to the constitution, are not so much so as either in the chancre or the gonorrhoea; for the lues venerea is attended with very little inflammation, which in general partakes much more of the nature of the constitution than any other diseased action.

§ 6. Of the specific Distance of the Venereal Inflammation.

I have already observed that many specific diseases, as also those arising from poison, have their local effects confined to certain distances, which I have called their local specific distance; and it would appear, from observation, that the venereal irritation and inflammation, of whatever kind it may be, is guided by this principle; for it seldom extends far beyond the surface that receives it; the neighbouring part not having a tendency to sympathize or run easily into this kind of inflammation. This is the reason why we find a gonorrhoea for weeks confined to one spot in the urethra in ^"irhp" T T S t0 the V?gina in women' not extending further in either. In chancres also the inflammation is confined to the seat of the sore without becoming so diffused as when from common OF THE LUES VENEREA. 249 accidents. As a further proof of this fact, we find it is also confined to the glands in the groin, in cases of buboes, till matter is formed in them; which matter acts as a common irritator, and the specific is in some degree lost, and then the inflammation becomes somewhat more diffused, as happens in common inflammation. We also see that the same thing happens in venereal ulcers when they arise from the constitution: their size is at first but small, and they are merely local; but as the disease increases the size increases, but they still remain circumscribed, not becoming diffused. Perhaps all poisons and specific diseases agree in this property of havinotheir inflammation limited and circumscribed in a manner peculiar to themselves; for we find that the inflammation of the small-pox, measles, and chicken-pox is each circumscribed in its own way. From hence it must appear that the human body in general is not so susceptible of specific irritations as it is of the common, or what may be called the natural. But we must also consider that the common inflammation in very healthy constitutions has its specific distance, although not so determined or circumscribed as is that of the specific in such constitutions; therefore we may reasonably suppose that such healthy constitutions are the furthest in disposition from the inflammatory action; and we may also suppose still more so from the specific. What would appear to strengthen this idea is, that when the constitution is such as readily goes into inflammation, the more readily does the inflammation spread, every part being susceptible of such action; and we find that in many the specific also spreads, although not in so great a degree, from which we may suppose that the specific is always a more confined mode of action. I have suspected that when the body was disposed to increase the inflammation beyond the specific distance, it was of the erysipelatous kind, as was mentioned before, and which is to be attended to in the cure.

§ 7. Of the parts most susceptible of the Lues Venerea—of the time and manner in which they are affected.— What is meant by Contamination, Disposition, and Action.—Summary of the Doctrine.

When I assigned the causes for so great a difference in the effects of the same poison upon two different surfaces, as forming the gonorrhoea and chancre, I then said I did not know whether similar surfaces in every part of the body were equally susceptible of this irritation, having but few comparative trials of* the direct application of the poison to other parts besides those of generation. But it would appear that some parts of the body are much less susceptible of the lues venerea than others; and not only so, but many parts, so far as we know, are not susceptible of it at all. For we have not yet had every part of the bcdy affected: we have not seen the brain affected, the heart, stomach, liver, kidneys, nor other viscera, although such cases are described in authors. But as there are different orders of parts respecting the times of the 22* 250 HUNTER ON THE VENEREAL DISEASE. disease appearing, and as the person commonly flies to relief upon the first or second appearances, it may be supposed that the whole disease in the parts actually affected is cured before the other parts have had time to come into action, which will therefore be cured under the state of a disposition only, if we can conceive that a cure can take place before the parts have come into action. But if the parts visibly affected are cured, while those only disposed are not, and afterwards come into action, they would form a second order respecting time; and if these again are cured, and other parts under a disposition should come into action, such would form a third order of parts respecting time. The lungs have been believed to have been affected with the venereal disease, both from the circumstances preceding the complaint, and from the complaint itself being cured by mercury; and their being affected, when the other viscera are not, may arise from their being in some degree an external surface, as will be explained hereafter. It is this form of the disease therefore that gives us the comparative susceptibility of parts both for disposition and action. For we must suppose that all parts are equally and at once exposed to the action of the poison ; but though there may be various degrees of susceptibility, it will be sufficient for practice to divide them into two, under the following appellations of first in order, and second in order, to which we may add the intermediate. Whether the parts that are really first affected are naturally more easily affected by this kind of irritation, or that some other circumstance which belongs to these parts is the cause, cannot be absolutely determined; but, the matter being attentively considered, it would appear to be owing to something foreign to the constitution, and also not depending on the nature of the parts themselves; for if we take a view of all the parts that are first affected by this disease, when arising from the constitution, which I shall suppose are the parts most susceptible of it, we shall see that in the recent state of the disease the parts are subject to one general affection, while there are similar parts of the body not affected by this disease, and not subject to this general affection. Probably the parts second in order may naturally be as susceptible of the irritation as those first in order; but not" being under the influence of an irritating cause, they are later in coming into action ; and there are also probably other causes in the nature of the parts themselves, such as being indolent in all their actions, and of course indolent in this, therefore later in coming into action. However, it is not universally the case that the parts which I have called first in order are always so; on the contrary, we find that this order is inverted in some cases, although but rarely. We cannot suppose that this difference arises from any active power in the poison, nor any particular direction of it, but from properties in the parts themselves; for it may be allowed us to suppose that when this matter has got into the circulation it acts on all parts of the body with equal force; that is, it is not determined to any one part more than another by OF THE LUES VENEREA. 251 any general or particular power in the animal machine; nor is the nature of the poison such as will fall more readily on one part ot the body than another, when they are all in similar circumstances. That some parts therefore are more readily affected by it tnan others, owing to circumstances which are no part ot the animal principle nor of the poison; and also that some parts of the body have a greater tendency to be irritated by it than others, must be

Q The parts that are affected by this form of the disease when in its early stage or appearance, which I have called first in order, are the skin, tonsils, nose, throat, inside of the mouth, and sometime. the tongue.* When in its later state, the periosteum, fascias and bones fome into action, and these I call second m order of pars Perhaps the bones come into action from the membrane being

^Thatwe maybe able to account in some m.easu* ^in^nd similar effects as to time in dissimilar parts such as the skinand the tonsils, two very different kinds of parts, let us insider injhat circumstance they agree, and why they are more susceptble o ^» irritation than thoae "parts that probably are naturaHy as much so, although they do not receive it so readily, such as the periosteum, fascia?, and bones. u-^u+ko OT*Prml The most remarkable circumstance perhaps to which the external surface is exposed, and to which the internal is not is coldor a succession of different degrees of cold. For we ™X°**™{™ general that the atmosphere in which we live is colder than the human bodyf in its usual temperature therefore the skin, &c s continually exposed to a cold greater than what theJ£^ are ; and we find that all those parts which are ™*™^£X admit of being much more easily affected, or come more readily into action in this disease than the others. It is certain that cold has very powerful effects on the animal economy. It would at least appear to have g^P^6^0^ posing the body for receiving the venereal irritation, and going

^to^a we may account for ^.^^-JS

^^ct^S^nU^nnd for the same reason come

k;0/.t to have ulcers formed on it, especially on its * The tongue is very subjec to have ulcers» ™ ■ , i or have edges. The! are seldom very ^J" ™ ^venereal but I believe they a hard basis : *™™™X**l"™*« "Y^ted with the distinguishseldom are. 1 <«° notj"0^^ £,I suspected lo be either venereal or cancerou? "otUs fouirokTnd'^rrd basis, ft gave way readily to mercury, therefore I supposed it to be Y"^fK t hold good as a universal principle: + It is to be understood that this cannot n g torrid lhe heat t U iS {° K "tcthi ht^,n^ fngid^^neTfo; in the torrid the heat 0^^^ Sometimesggreater than that of the human

body. 25-2 HINTER ON THE VENEREAL DISEASE very readily into action. If this be a true solution, it also accounts for those second in order being affected; for if the poison has contaminated parts which are both first in order of susceptibility and time of coming into action, it is natural to suppose that those parts which are most predisposed, as the external surfaces, shall com first into action; the parts exposed to cold, in the next degree, forming the second in order, come next into action, such as bones, periosteum, &c.; but even in them it is not in every bone alike, or every part alike of any one bone, for it appears first in those that are in some measure within the power of being affected by sympathy from application of cold to the skin: we find that when the deeperseated parts, or the parts second in order, come into action, such as the periosteum or bones, it is first in these that are nearest the external surface of the body, such as the periosteum or bones of the head, the tibia, ulna, bones of the nose, &c, nor does it affect these bones on all sides equally, but first on that side next the external surface. However, it would appear that in the bones there is another cause, besides the vicissitudes of weather, why this disease should attack them ; for the periosteum of bones, or bones themselves, are not liable to be diseased on all parts in proportion to the distance from the skin, the periosteum which covers the ankles, or many of the joints, being as near the external surface as many other parts of the periosteum or bones that are affected. The nature of the bones themselves, which are covered by that periosteum, is somewhat different: they are softer in their texture, therefore they would seem to be affected in proportion to their nearness to the skin and hardness of the bones jointly; which would incline us to believe that the bones are more easily affected, and rather have some influence upon the periosteum in this disease than the periosteum upon them ; and this susceptibility in the hard bones would appear to be in proportion to their quantity of earth and exposure to cold combined. It may be objected to this theory, that the fore part of the tibia, &c, cannot be really colder than the back part; but then it may be supposed that it is not necessary that the part should be actually cold, but only within the power of sympathy. For a part that is not actually cold is capable of being affected from its sympathizing with a cold part in the same manner as if actually cold, although perhaps not in so great a degree, and therefore requires a longer time to come into action than if it were actually cold. We find, for example, that when the skin is actually cold the muscles underneath are thrown into alternate action, so that we tremble, or our teeth chatter with cold, and yet it is possible that these muscles may not be colder at this time than any other; although it is most probable that they are really colder,* which will assist the power of sympathy. So far as cold can affect the actions of parts, so far also will the sympathizing part be affected in proportion as it is

* See Philosophical Transactions, vol. 68, part i. page 7, OF THE LUES VENEREA. 253 nearer to the parts actually cold; therefore the deeper-seated parts in the venereal disease are later in coming into action. The actual cold parts come first into action, then those that are less so, and next those that are nearest in sympathy, and so on, except the parts first in order of susceptibility have been only partially cured, and then their recurrence may correspond with the action of those that are second in order of susceptibility, and all the parts will come into action together. What would seem to strengthen this opinion is the different effects that arise from different climates; in warm climates the disease seldom or never arises to such a height as in cold climates; it is more slow in its progress, and much more easy to cure, at least if we may give credit to the accounts we have received of the disease in such climates. Whether the difference in the time of appearance between the superficial and deeper-seated parts in warm climates is the same as in cold ones, I do not know, but from the above theory it should not be so great in the warm as in the cold climates. Besides the causes already mentioned, it would appear that there are others by which the lues venerea may be brought sooner into action than it otherwise would be if left entirely to the nature of the constitution; for I think I have seen cases where fever has brought it into action when the disposition had been previously formed. Like most other diseases to which there is a susceptibility or disposition, we find that any disturbance in the constitution shall call it forth: scrofula, gout, and rheumatism are often called forth in this way. Having said that the deeper-seated parts of the body come into action later than those that are superficial, I shall now observe, that when the lues venerea has been cured so far as only to remove the first actions, but not to eradicate the disposition in the deeper-seated parts, as has been explained, under such circumstances of the disease it never attacks again the external, or the parts that were first affected, but only the deeper-sealed parts which are second in order of time. The reason is, that the deeper-seated parts had not been affected at the time of the cure of the first. The following cases, selected from a great number of similar ones, will illustrate the doctrines we have laid down. In January, 1781, A. B. had connexion with a woman, and two days after perceived an itching in the glans: at the end of four days he found chancres upon the prepuce. He took about twenty grains of calomel, and then applied to a surgeon under whose care he remained three months, that is, till April. He thought himself nearly well, and went into the country, taking a few pills with him, and at the end of another month believed himself perfectly cured. Three months after, that is, in August, he caught cold, and had considerable fever, for which James's powders were given. Soon after this, spots of a copper colour appeared upon his legs, and he had violent pains in his shin bones. By the order of a country surgeon, he rubbed in about an ounce of mercurial ointment, ana 254 HUNTER ON THE VENEREAL DISEASE. had a slight spitting; the pain ceased, the spots disappeared, and in a month he again conceived himself to be well. This was in October, 1781. In June, 1782, he had the influenza; about a fortnight afterwards his left eye inflamed, and he had a pain in the head, and a noise in his ears. Five days afterwards his throat became sore. Three weeks after the inflammation of his eye several pustules made their appearance near the anus. These symptoms remained till the 21st of August, when he came into St. George's Hospital. He rubbed in strong mercurial ointment till his mouth became sore; he sweated very much; the pain in his head remained, but the complaint in his eye, and about the anus, together with the sore throat, were totally removed. It appears that in this case some additional power was required to dispose the body more readily to exhibit venereal symptoms. That cold has a strong power of this kind we have allowed, which appears in this case to have been the first immediate cause; but a fever seems to have been equally effectual in producing the second return of the symptoms. Here was the venereal disposition in the constitution from April, 1781, the time he was cured of the local complaint, till June, 1782, fourteen months after; and then it reappeared eleven months after that, which periods might have been longer, if it had not been called forth by the two circumstances of cold and fever. Let us consider how far this case corresponds with the opinion of the action being easier of cure than the disposition. The first action, that is, the chancres, were perfectly cured by the quantity of mercury he took at first, for they never recurred; but the venereal matter had produced the disposition in the constitution, which was not cured by the same quantity of mercury, for blotches appeared three months after; but all the parts that had taken on the disposition at that time had not then come into action, therefore only the parts which had come into action were cured by the second course of mercury, and the other parts which had not yet taken on the action went on with the disposition till the influenza (which happened eleven months after,) brought them into action. The first class of pocky appearances were perfectly cured by the second course of mercury, as the local had been cured by the first, for they never reappeared, not even with the second. The second set of pocky symptoms, we have observed, appeared to be perfectly cured by the third course of mercury. How far there may be a third set of pocky symptoms to come forth time can only tell This case further proves, that sometimes the second set of symptoms appear first, and the first second ; and also shows the difference in times between the first pocky appearances after the healing of the local, and between the second appearance of the symptoms after the healing of the first. J L A gentleman had a chancre in May, 1781; in the same month of the next year, 1782 he had a gonorrhoea; and in May, 1783, he had a sore throat. He had no connexion with any woman from OF THE LUES VENEREA. 255 September, 1782, till May, 1783, which was about a fortnight before his throat became sore, and had had no immediate local complaints. When I saw the throat first I said it was not venereal; and he being rather of a hectic habit, was desired to go to Bristol. When at Bristol an ulcer appeared at the root of the uvula, which made him immediately come back to London. When I saw this ulcer I said it was venereal. He now went through what I supposed was a sufficient course of mercury, and all the venereal symptoms appeared to be cured.* He went into the country about the month of August, and about the beginning of January, 1784, viz. four months after the supposed cure, he felt a pain, together with a swelling, in his shin bones, for which he went through a course of mercury, which removed both the pain and the swelling. In this case we have every reason to suppose that the disposition had taken place in the bones or their coverings, from the same cause that affected the uvula; but the uvula suffered first, being of the first order of parts. Whether this was really the case or not, we must allow that in the parts second in order, the disposition, and not the action, did exist at the time when the disease in the uvula came into action, as also at the time when he went through a course of mercury sufficient to cure the uvula; we must also allow that the disposition was not removed by the quantity of mercury which was capable of removing the disease in the uvula. From all which I would draw the following inferences in confirmation of the preceding doctrine: first, that the parts about the throat are capable of assuming the action sooner than the bones; secondly, it is probable that mercury can cure the action only, and not the disposition; and thirdly, that the venereal pus is not present in the circulation while the secondary actions take place ; for if it were, the parts first in order would stand an equal chance of being again contaminated, and of coming into action a second time. Supposing the venereal matter still to exist in the constitution after the parts first thrown into action are absolutely cured, so as to contaminate the parts that are second in order of action, we should certainly have the parts first in order to take on the disease a second and even a third time, and so on, while the second or third in order would be going on and only coming into their first action; and therefore we might have those that are first in order, and those that are second in order, in action at the same time. This might be carried still further, for as it tis possible for the parts first in order of susceptibility to have the disease a second time, while the parts second in order are under the influence of the first infection, those first in order may be contaminated a second time from a new or fresh infection, which would be a lues venerea upon a lues venerea, a case which certainly may happen. If the matter does really con- * I may remark here, that only the venereal ulcer got well by the mercury ; for the former excoriation of the throat continued, but was afterwards cured by bark and sarsaparilla. 256 " HUNTER ON THE VENEREAL DISEASE. tinue in the constitution, it would be natural to suppose that the parts most easily affected by it would remain so long as the poison remained. It may indeed be alleged, that parts which have already been accustomed to this irritation, and cured, are rendered by that means less susceptible of it. If the poison were still capable of circulating after its visible effects were cured, then mercury given in the time of a chancre can be of little service, as it can only assist in the cure of the chancre, but cannot preserve the constitution from infection, which does not agree with experience; for practice informs us, that not one in fifty would escape the lues venerea if the chancre were only cured locally ; so that mercury has the power of preventing a disposition from forming, and therefore is necessary to be given while we suppose absorption going on, or while there is matter that may be absorbed. Mercury, prior to the action, will not remove the disposition, and of course will not hinder the action coming on afterwards; however, it is possible, and most probable, that the medicine while it is present will hinder the action taking place ; so that no venereal complaints will take place under the course of mercury, although the parts may be contaminated. This is not peculiar to the venereal disease, but common to many others; and in some it may be reversed, for there are diseases whose disposition can be cured, and therefore the action prevented by such medicines as would rather increase the action if given in the time of it. The part first affected are more easily cured, according to our present method, than the parts second in order. A part once perfectly cured is never irritated again by the same stock of infection, though probably some other parts in the constitution are stiff under the venereal irritation. If the facts stated be just, the circumstance of the disease appearing to leave the parts first attacked, and attacking the secondary parts, is easily accounted for. It is no more than the first parts being cured while the secondary are not, and of course going on with the disease, the first remaining well. If this mode of accounting for these circumstances be just, it proves two things ; first, a former assertion, that this disease, in the form of lues venerea, has not the power of contaminating parts not already under its influence, even in the same constitution; secondly, that the venereal poison is not circulating in the blood all the time the disease is going on in the constitution ; so that most probably the poison only irritates when just absorbed, and is soon expelled or thrown out in some of the secretions. The above account of the lues venerea may be reduced to the following heads: First, that most parts, if not all, that are affected in the lues venerea, are affected with the venereal irritation at the same time. Secondly, the parts exposed to cold are the first that admit the venereal action ; then the deeper-seated parts, according to their susceptibility for such action. & OF THE SYMPTOMS OF THE LUES VENEREA. 257

Thirdly, the venereal disposition, when once formed in a part, must necessarily go on to form the venereal action. Fourthly, that all parts of the body, under such disposition, do not run into action equally fast, some requiring six or eight weeks, others as many months. Fifthly, in the parts, that come first into action, the disease goes on increasing without wearing itself out, while those that are second in time follow the same course. Sixthly, mercury hinders a disposition from forming, or, in other words, prevents contamination. Seventhly, mercury does not destroy a disposition already formed. Eighthly, mercury hinders the action from taking place, although the disposition be formed. Ninthly, mercury cures the action. These principles being established, the facts respecting the cure are easily accounted for. CHAPTER II.

OF THE SYMPTOMS OF THE LUES VENEREA.

When the venereal matter has affected the constitution in any of the ways before mentioned, it has the whole body to work upon, and shows itself in a variety of shapes ; many of which putting on the appearance of a different disease, we are often obliged to have recourse to the preceding history of the case before we can form any judgment of it. Probably the varieties in the appearances may be referred to the three following circumstances : the different kinds of constitutions, the different kinds of solids affected, and the different dispositions which the solids are in at the time; for I can easily conceive that a peculiarity of constitution may make a very material difference in the appearance of the same specific complaint, and I am certain that the solids, according to their different natures, produce a very different appearance when attacked with this disease ; and I can also easily conceive that a different disposition from the common in the solids at the time may make a considerable difference in the appearances. The difference of constitution, and of the same parts at different times, may have considerable effects in the disease with respect to its appearing sooner or later. This lam certain of, that the different parts of the body produce a very considerable difference in the times of appearance of this disease. That it appears much sooner in some parts than in others is best seen where different parts are affected in the same person; for I have already endeavoured to show that it is most probable that all the parts affected are con- 23 258 HUNTER ON THE VENEREAL DISEASE. taminated nearly at the same time. This difference in the times is either owing to some parts being naturally put into action more easily by the poison than others, or they are naturally more active in themselves, and therefore probably will admit more quickly the action of every disease that is capable of affecting them. When on the general history of the lues venerea, I divided the parts into two orders, according to the time of their appearance. I also observed that the first were commonly the external parts, as the skin, nose, tonsils; and that the second were more internal, as the bones, periosteum, fasciae, and tendons. The time necessary for its appearance, or for producing its local effects in the several parts of the body most readily affected, after it has got into the constitution, is uncertain, but in general it is about six weeks ; it many cases, however, it is much later, and in others much sooner. In some cases it appears to produce its local effects within a fortnight after the possibility of the absorption of the matter. In one case a gentleman had a chancre, and a swelling in the groin came on, and within the before-mentioned time he had venereal eruptions all over the body. He could not impute this to any former complaint, yet there is a possibility of its having arisen from the first mode of catching the disease, by simple contact, at the time he got the local or chancre, which might extend the time to a week or more, although this is not probable. In another case, three weeks after the healing of a chancre, eruptions broke out all over the body, and this happened only a fortnight after leaving off the course of mercury that cured the chancre. The effects on other parts of the body, that are less susceptible of this irritation, or are slower in their action, are of course much later in appearing; and in those cases where both orders of parts are contaminated it is in general not tilt after the first has made its appearance for a considerable time, and even perhaps after it has been cured; for while the parts first in order of action were contaminated and under cure, the second in order are only in a state of contamination, and go on with the disease afterwards, although it may never again appear in the first. From this circumstance of the parts second in order coming later into action, we can plainly see the reason why it shall appear in them, although the first in order may have been cured; for if the external parts, or first in order, have been cured, and the internal, or second, such as the tendons, bones, periosteum, &c, have not been cured, then it becomes confined solely to these parts. The order of parts may sometimes be inverted ; for I have seen cases where the periosteum, or bone, was affected prior to any other part. Whether in the same case it might in the end have affected the skin or throat I will not pretend to say, as it was not allowed to go on ; but it is possible that the second order of parts may be affected without the first having ever been contaminated. Its effects on the deeper-seated parts are not like those produced in the external, and the difference is so remarkable as to give the OF THE SYMPTOMS OF THE LUES VENEREA. 259

appearance of another disease; and a person accustomed to see it in the first parts only would be entirely at a loss about the second. The parts which come first into action go on with it, probably on the same principle, much quicker than the others ; and this arises from the nature of the parts, as has already been observed. Each succeeding part that becomes affected is slower and slower in its progress, and more fixed in its symptoms when produced; this arises also from the natural disposition of such parts, all their actions being slow, which indolent action may be assisted by the absence of the great disposing cause, that is cold. I should, however, suspect that warmth does not contribute much to their indolence of action ; for if it did it would assist in the cure, which it appears not to do, these parts being as slow in their operations of restoration as they are in their actions of disease. We may also observe that similar parts come sooner into action, and appear to go on more rapidly with it, as they are nearer the source of the circulation. It appears earlier on the face, head, shoulders, and breast than on the legs, and the eruptions come sooner to suppuration in the before-mentioned parts.* The circumstance of its being very late in appearing in some parts, when it had been only cured in its first appearances, as mentioned, has made many suppose that the poison lurked somewhere in the solids; and others that it kept circulating in the blood for years. It is not, however, easy to determine this point; hut there can be no good reason for the first hypothesis, as the lurking disposition never takes place prior to its first appearance; for instance, we never find that a man had a chancre a twelvemonth ago, and that it broke out after in venereal scurfs upon the skin, or ulcers in the throat. The slowness of its progress is only when the parts less susceptible of its irritation have been affected by it

§ 1. Of the Symptoms of the first stage of ihe Lues Venerea.

The first symptoms of the disease, after absorption, appear either on the skin, throat, or mouth. These differ from one another according to the nature of the parts affected. I shall therefore divide them into two kinds, although there appears to be no difference in the nature of the disease itself. The appearance on the skin I shall call the first, although it is not always the first appearance ; for that in the throat is often as early a symptom as any. The appearances upon the skin generally show themselves in every part of the body, no part being more susceptible than another, first in diseolorations, making the skin appear mottled, many of them disappearing, while others continue and increase with the disease.f * See Introduction. f This is aot peeuliar to this disease; it often takes place in the small-pox. 260 HUNTER ON THE VENEREAL DISEASE. In others it will come on in distinct blotches, often not observed till scurfs are forming; at other times they appear in small distinct inflammations, containing matter and resembling pimples, but not so pyramidal, nor so red at the base. Venereal blotches, at their first coming out, are often attended with inflammation, which gives them a degree of transparency, which I think is generally greater in the summer than in the winter, especially if the patient be kept warm. In a little time this inflammation disappears, and the cuticle peels off in the form of a scurf. This sometimes misleads the patient and the surgeon, who look upon this dying away of the inflammation as a decay of the disease, till a succession of scurfs undeceives them. These discolorations of the cuticle arise from the venereal irritation, and are seldom to be reckoned a true inflammation, for they seldom have any of its characteristics, such as tumefaction and pain; but this is true only on those parts most exposed, for in parts well covered, and in parts constantly in contact with other parts, there is more of the true inflammatory appearance, especially about the anus. The appearance of the parts themselves next begins to alter, forming a copper-coloured dry inelastic cuticle, called a scurf; this is thrown off, and new ones are formed. These appearances spread to the breadth of a sixpence or shilling, but seldom broader, at least for a considerable time, every succeeding scurf becoming thicker and thicker, till at last it becomes a common scab, and the disposition for the formation of matter takes place in the cutis under the scab, so that at last it turns out a true ulcer, in which state it commonly spreads although but slowly. These appearances arise first from the gradual loss of the true sound cuticle, the diseased cutis having lost the disposition to form one; and, as a kind of substitute for this want of cuticle, an exudation takes place, forming a scale, and afterwards becoming thicker, and the matter acquiring more consistence, it at last forms a scab; but before it has arrived at this stage the cutis has given way, and ulcerated, after which the discharge becomes more of a true pus. When it attacks the palms of the hands and the soles of the feet, where the cuticle is thick, a separation of the cuticle takes place, and it peels off; a new one is immediately formed, which also separates, so that a series of new cuticles takes place, from its not so readily forming scurfs as on the common skin. If the disease is confined to those parts it becomes more difficult to determine whether or not it be venereal, for most diseases of the cutis of these parts produce a separation of the cuticle attended with the same appearances in all, and having nothing characteristic of the venereal disease. Such appearances are peculiar to that part of the common skin of the body which is usually exposed; but when the'skin is opposed by another skin which keeps it in some degree" more moist, as between the nates, about the anus, or between the OF THE SYMPTOMS OF THE LUES VENEREA. 261 scrotum and the thigh, or hi the angle between the two thighs, or upon the prolabium of the mouth, and in the armpits, the eruptions never acquire the above-described Appearances, and instead of scurfs and scabs we have the skin elevated, or, as it were, tumefied by the extravasated lymph into a white, soft, moist, flat surface, which discharges a white matter. This may perhaps arise from there being more warmth, more perspiration, and less evaporation, as well as from the skin being thinner in such places. What strengthens this idea still more is, that in many venereal patients I have seen an approach towards such appearances on the common skin of the body; but this has been on such parts as were covered with the clothes, for on those parts of the skin that were not covered there was only the flat scurf; these however were redder than the above described appearances, but hardly so high. How far this is peculiar to the venereal disease I know not. It may take place in most scurfy eruptions of the skin. From a supposition of this not being venereal, I have destroyed them at the side of the anus with a caustic, and the patient has got well; however, from my idea of the disease, that every effect from the constitution is truly local, and therefore may be cured locally, a cure effected by this treatment does not determine the question. This disease, on its first appearance, often attacks that part of the fingers upon which the nail is formed, making that surface red which is seen shining through the nail, and, if allowed to continue, a separation of the nail takes place, similar to the cuticle in the before-described symptoms; but here there cannot be that regular succession of nails as there is of cuticle. It, also attacks the superfices of the body which is covered with hair, producing a separation of the hair. A prevention of the growth of young hair is also the consequence while the disease lasts.*

* [The variety of venereal eruptions is so great as almost to baffle description. Hence pathologists have usually contented themselves with fixing on some one characteristic which was generally applicable,-and have neglected any attempt at distinct classification, or more accurate and detailed delineation. Thus the copper colour has been assigned by some, and the circular form by others, as the distinguishing character. Yet these general tests tend only to mislead, since the firs*t is wanting in many species of venereal eruption, and the second is shared also by the great majority of eruptions which are not venereal. It must be confessed that in the present state of our knowledge it would be impossible to produce a complete history of every form of venereal eruption. There are many sorts which are so indistinct and uncertain in their character that it would be difficult to find their proper place in any arrangement, and equally difficult to point out any constant and invariable signs by which they may be always identified. Yet the species of eruption which are of most frequent occurrence, and which are in practice of the greatest importance, are sufficiently distinct to admit of classification ; and it is obvious that a clear history of the aspect and course of these more common forms of eruption must greatly elucidate the whole subject, and ultimately facilitate the knowledge of those other varieties which are not included in the list. The mottled state of the skin, to which allusion is made by the author, is certainly found in venereal cases. Yet a similar appearance is often seen in cases J 23* 262 HUNTER ON THE VENEREAL DISEASE.

The second part in which it appears is most commonly the throat, sometimes the mouth and tongue. In the throat, tonsils, and

where no venereal cause can be assigned; nor does there seem to be any peculiarity by which the one case can be distinguished from the other. It may be doubted whether this mottled colour denotes more than an irritability of the skin, and a general disposition to eruptive disorders. The more distinct sorts of venereal eruption may be divided into the following classes: I. Tubercles.—The original seat of the tubercle is probably in the sabaceous glands, certainly in some structure which is below the surface of the cutis. This is sufficiently evident from its aspect at the period of its commencement. It appears in the first instance as a small hard substance like a pea, which may be ielt by the finger before there is sufficient discolouration to attract the notice of the eye. At this period the eruption is scarcely discernible if the light falls directly on the part, though if it is viewed by a side-light the prominence is sufficient to cast a distinct shadow. However, this stage is of short duration : the inflammation soon reaches the surface, and the spot then wears the appearance of a small red elevation, evenly rounded on the surface. In the next place the cuticle dies, and becomes detached from the cutis ; but it usually remains for a time, forming a horny cap, which covers the surface, and protects the formation of a new cuticle beneath. In this state it frequently resembles a large vesrele, but the appearance is deceptive. If the dead cuticle be removed by a probe, not a particle of fluid will be found under it. The tubercle may remain in this state with little change, except that it slightly enlarges, and that successive layers of cuticle desquamate from the surface. But it often happens that it goes on to ulceration. In such cases the ulcer always commences at a central point, which is slightly depressed, and may be distinctly seen on the first removal of the cuticle, and which appears to be the orifice of the sabaceous duct. As the ulcer proceeds it usually destroys the centre of the tubercle only, and leaves an indurated and elevated portion, by which it is encircled and separated from the sound skin. In the progress of the ulcer this tubercular thickening continues to precede it, so that there is always a margin of red induration, more or less marked, as the powers of the system are greater or less; frequently of considerable breadth in those who are strong and vigorous, but in the feeble often so slight as to be scarcely distinguishable" yet in all cases leaving, as it subsides, the peculiar brown stain, which is the chief characteristic of the tubercle. It is from this stain that the tubercle has received the appellation of the copper blotch. The hue varies with the age and ihe progress of the eruption. In the earliest stages it differs in nothing from that of common inflammation, and is efiaceable, or nearly so, on pressure. But in a short time a yellow or copper tinge is blended with the florid red, and gives it a peculiar brightness, the cause of which is made evident by passing the finger over the spot. The vessels are thus emptied for the moment, and the florid arterial colour disappears, but the yellow or copper stain remains unchanged, and is shown to depend on something which has been effused on the surface, and which cannot be removed by pressure. While the tubercle is stationary the colour becomes deeper, and more yellow, but retains much of its brightness; but as the disease is subdued, and as the tubercular thickening subsides under treatment, the copper tinge gradually fades away, and gives place to a dirty brown. Though the hue is chanced, the stain remains equally indefiible, even at a time when all elevation has disappeared, and the spot is on the same level with the surrounding skin. There is still a later stage, at which this brown stain gradually fades away, and the seat of the spot is altogetherundis?!inguishable. r This Peculiar stain is not found in all forms of venereal eruption; it seems to be confined to the varieties of the tubercle; and there is reason to think that its exact nature and cause m ght be ascertained if wo ),j'/i ■ \? ., r ., . o . c "si-enainea it we naa a fuller acquaintance with ceouTghTndl ** ** ^ 3nd with lhe functi°ns of the%aba- 2. Lichma.-This eruption consists of small acuminated pimples, of a red OP THE SYMPTOMS OF THE LUES VENEREA. 263 inside of the mouth, the disease generally shows itself at once, in the form of an ulcer, without much previous tumefaction, so that

colour, which are sometimes evenly scattered over the surface, at other times arranged in patches. It is not correct to characterize this eruption, as has been sometimes done, by the absence of suppuration. Many of the papulae imperfectly suppurate; that is, a small quantity of opake serum is effused under the cuticle at the apex, and this serum soon becomes purulent: but the pus never accumulates; in a few days the greater part is absorbed; the rest dries into a small scab ; and when this scab falls off, no ulcer, or depression, or cicatrix, is left behind. The pus is effused from the surface of the cutis, and is altogether unattended by ulceration. ,,,,/., i u ♦ Lichens differ much in the size of the papula and the depth of the colour; but they have one character which is very generally present, and which is shared by no other venereal eruption. They tend to pass spontaneously through their successive stao-es, and then spontaneously to subside. In other venereal eruptions the course of the disease in the skin is a test of the course of the disease in the general system. A diminution in the eruption argues an improvement in the affection of the constitution. In lichen, on the contrary, the colour may fade, and the elevation diminish, at a time when other symptoms are continuing to increase, and even when a fresh crop of lichen is appearing. Hence the same case lrequently presents specimens of every stage of this eruption, from the first rise oi the small papula, before maturation has taken place, to the period when all elevation has subsided, and the seat of the spot is marked only by a pale or purple discolouration of the skin, which is effaceable by the pressure of the finger. 1 his progress towards recovery, which often occurs spontaneously, may be very readily produced by remedies, which are altogether inadequate to cure the disease, especially if they are exhibited when the eruption has run through its natural periods, or about a fortnight or three weeks from the date of its appearance. Yet this natural tendency to pass off is subject to exceptions. It sometimes happens that the small papula continues slowly but steadily to enlarge, and at length attains the size, and assumes the copper stain, and all the other characters°of the tubercle. A close examination shows the mode in which this change takes place. The lichenous papula is situated on one of those small elevations on the surface of the cutis, which mark the orifices of the ducts that perforate the cutis, and proceed to the glands which are situated beneath it. 1 he inflammation, which began on the surface, gradually extends down the duct, and involves the sebaceous gland which is at the bottom. This tubercular lichen is not so much a peculiar form of lichen, as an eruption of lichen passing into an eruption of tubercles, by a process which is very easily understood. In such cases the subsequent course and the treatment are exactly those of the tubercle. Most forms of Lichen present no indellible stain. But where the eruption has been unusually lasting there will be seen, after the subsidence of the papula, a brown stio-rna, occupying a central point, and commonly presenting an appearance of degression or pitting. This appearance is, however, in almost all cases delusive PIt arises from the stain being situated deep in the substance of the cu is, and shining through the more superficial parts, which are tranjparent. These stigmata seem to characterize an earlier and more imperfect form of the p^cedinaCrety There has been an attempt to form a tubercle, but the com- J ainthas been arrested before the sebaceous gland has been fully involved. P 3'Psoriasis and Z^m.-Scaly eruptions are very common in venereal cases, but'thev differ little from those which occur from other causes. They appear generally in small circular spots, but they vary much in the degree of elevation, the size of the spot, and the depth of the colour; yet they never assume the copper tnge of the'tubercle. The colour is rather sandy and ts ,n almost all in- Lances nearly effaceable by pressure. The difference of colour, the superficial origin of these eruptions, and the total absence of ulceration in all forms and etJtre* sufficiently distinguish them from tubercles. f Ilupia'-This eruption shows itself at first by a slight blush on the surface. 264 HUNTER ON THE VENEREAL DISEASE, die tonsils are not much enlarged; for when the venereal inflammation attacks these parts, it appears to be always upon the surface, and it very soon terminates in an ulcer. These ulcers in the throat are to be carefully distinguished from all others of the same parts. It is to be remarked, that this disease when it attacks the throat, always, I believe, produces an ulcer, although this is not commonly understood ; for I have seen cases where no ulceration had taken place called, by mistake, venereal.

Generally in a few hours, sometimes at a longer period, the cuticle at this part is elevated into a small blister, by the effusion of opake serum, which soon becomes purulent, and shortly afterwards concretes into a scab. The disease spreads by a process in all respects similar. Effusion takes place under the cuticle at the edge, and the concretion of this effusion enlarges the diameter of the scab, and elevates it from the surface of the cutis. Hence the scab as it grows consists of a series of concentric layers, those towards the apex having been formed at the commencement of the disease, and being consequently small in size; those at the base, which have been formed by the latest effusion, beinocommensurate with the present size of the sore. The accumulation of the whole forms a cone, which projects like a horn when the extension of the ulcer has been slow, but has a wide base and comparatively a slight projection where the ulcer has rapidly enlarged. That rupia begins on the smface of the cutis is manifest, not only from the course of the ulcer, but also from the aspect of the cicatrix which it leaves The sore most frequently heals first at the centre, an island of skin formine there while the edges are still stationary, or even spreading; and this is an occurrence which is known to be extremely rare in ulcers which have destroyed the whole substance of the cutis. Again, after the sore has healed, the surface of the cicatrix, especially near the edges, often presents distinctly to the eye the minute points that mark the ducts which perforate the cutis, and which must have been destroyed if the whole thickness of the cutis had been involved. Some cases of ulcerating tubercles closely resemble rupia; but in rupia there is neither tubercular thickening nor copper stain. When these exist at theedcres of the sore the eruption is not rupia, but tubercle, passing rapidly into ulceration. In such cases the spots which resemble rupia will generally be found intermixed with distinct tubercles, and the treatment required will be that which is adapted to the tubercle.

to ™lrT]£l LeTeal eruPU-T S-em t0; partake of the characters which belong to rupia, as far as the superficial or.gin, the mode of extension, and the accumulation of the crust are concerned ; but they differ much in the'degree of inflammation which precedes the format.on of matter, and the size of the original pustule. In genuine rupia the vesicle is preceded only by a slight blush of inflammation, and at its first appearance is nearly of the size of a silver penny But it often happens that the inflamed spot is smaller, and somewhat more elevated and that the fluid effused is purulent from the first, and forms Imedialely a small scab at the top of the eminence. Such a spot resembles aCommon nL tule, and the small size of the scab, and the slowness ontfpro.ress, gTv it an' appearance which is not readily recognised as that of rupia/ Yet it if difficult to point out any essential difference; and if the ulcer be allowed to ncreasT tie aspect m the more advanced stages will be precisely similar. The descrinlio therefore, which has been given may be taken as applicable to pustulaTenveil eruptions in general, if not n all the minuter detail «,» i„»lt P ,"Iar venereal and essential characters. ailS' at leasl ,n lhe prominent It must not be forgotten that this classification of venereal eruptions is intended to include the principal varieties only, and that other form- Jff ?•,ntended vhich are less frequent and less distinctly maied but Sffch ZetTomtheTs' toryof the case, and the accompanying symptoms, must be reffl toT venereal OP THE SYMPTOMS OF THE LUES VENEREA. 265 It is therefore only this ulcer that is to be distinguished ffom other ulcers of these parts. This species of ulcer is generally tolerably well marked, yet it is perhaps in all cases not to be distinguished from others that attack this part, for some have the appearance of being venereal, and what are really venereal resemble those that are not. We have several diseases of this part which do not produce ulceration on the surface, one of which is common inflammation of the tonsils, which often suppurates in the centre, forming an abscess, which bursts by a small opening, but never looks like an ulcer begun upon the surface, as in the true venereal; this case is alwavs attended with too much inflammation, pain, and tumefaction of the parts to be venereal; and if it suppurates and bursts it subsides directly, and it is generally attended with other inflammatory symptoms in the constitution. There is another disease of these parts, which is an indolent tumefaction of the tonsils, and is peculiar to many people whose constitutions have something of the scrofula in them, producing a thickness in the speech. Sometimes the coagulable lymph is thrown out on the surface, and called by some ulcers, by others sloughs, and such are often called putrid sore throats. Those commonly swell to too large a size for the venereal; and this appearance is easily distinguished from an ulcer or loss of substance : however, where it is not plain at first sight it will be right to endeavour to remove some of it; and if the surface of the tonsil is not ulcerated, then we may be sure it is not venereal. I have seen a chink filled with this, appearing very much like an ulcer, but upon removing the coagulable lymph the tonsil has appeared perfectly sound. I have seen cases of a swelled tonsil where a slough formed in its centre, and that slough has opened a passage out for itself, and when it has been, as it were, sticking in this passage, it has appeared like a foul

" The most puzzling stage of the complaint is when the slough is come out, for then it has most of the characters of the venereal ulcer; but when I have seen the disease in its first stages I have always treated it as of the erysipelatous kind, or as something ot the nature of a carbuncle. When I have seen them in their second stage only I have been ant to suppose them venereal; however, no man will be so rash afto pronounce what a disease is from the eye only, but will make ?naSnPeT?nto all the circumstances before he forms a judgment. If h2rehaveb^n no preceding local symptoms within the proper date he will suspend his judgment, and wait a little to see how far Nature iTable to relieve herself. If there has been any preceding fover it wdl be still less probable that it is venereal. However, I will not sTy of what nature such cases are, but only that they are « venereal as they are often believed to be. 1 have seen a sore throat of ths kind mistaken for venereal, and mercury given till it <J t J? the mouth which when it did, it brought on a mortification 0^ tt pa^concerned in the first disease' It would therefore 266 HUNTER ON THE VENEREAL DISEASE. appear that this species of the sore throat is aggravated by mercury. There is another complaint of those parts which is often taken for venereal, which is an ulcerous excoriation, where the ulceration or excoriations run along the surface of the parts, becoming very broad, and sometimes foul, having a regular termination, but never going deep into the substance of the parts, as the venereal ulcer does. There is no part of the inside of the mouth exempted from this ulcerous excoriation, but I think it is most frequent about the root of the uvula, and spreads forwards along the palatum molle. That such are not venereal is evident, from their not giving way in general to mercury; and I have seen them continue for weeks without altering, and a true venereal ulcer appear upon the centre of the excoriated part. The difference between the two is so strong that there can be no mistake; patients have gone through a course of mercury which has perfectly cured the venereal ulcers, but has had no effect upon the others, which have afterwards been cured by bark. The true venereal ulcer in the throat is perhaps the least liable to be mistaken of any of the forms of the disease. It is a fair loss of substance, part being dug out, as it were, from the body of the tonsil, with a determined edge, and is commonly very foul, having thick white matter adhering to it like a slough, which cannot be washed away. Ulcers in such situations are always kept moist, the matter not being allowed to dry and form seabs, as in those upon the skin; the matter is carried off the ulcers by deglutition or the motion of the parts, so that no succession of scurfs or scabs can take place, as on the skin. r Their progress is also much more rapid than on the common skin, ulceration taking place very fast. Like most other spreading ulcers, they are generally very foul, and for the most part have thickened or bordered edges, which is very common to venereal or cancerous sores, and indeed to most ease^Ja be.*^ n° disp°siti°n t0 heal* whatever the specific disand SmrtheS,an1f,ieatVtf^ l" l™?*? SOre throats as in V€ner*al eruptions, fess'easUv observed V. Part'«heud,8tWshinff characters are, on the whole to be noticed C ^ P"nCipal SpecieS are efficiently distinct

of Vhe^nSr Tnt™lTfje™r] «"•*"* 3PPearS to begin in th* centre

attention is from any cause directed to Z SS? * d,8?nct ulcer' But if sometimes be discovered The nnVu Jhe,thr°atf.an earlle' appearance may appearance may bTset 1^1^ ! K?d dl**% >wellea,and .yellow

tion takes place, and disclosed" ySow « whiShT"-^ " *"' 0r tW° ulcera" the centre of the tonsil. There if ktW„i °U^' Penetrati"g deep into are not violently inflamed. There ssn"!^6"16^' a"d,the Grounding part* time of swallowing ; but there iTon the Sho^Cf AnC,i,n8'/5Pecial,y a* the less uneasiness than might be expect 7^^ OF THE SYMPTOMS OF THE LUES VENEREA. 267 When it attacks the tongue it sometimes produces a thickening and hardness in the part; but this is not always the case, for it very often ulcerates, as in the other parts of the mouth.

the ulcer. As it spreads, however, the surrounding parts become involved, and then it occasions more distress. The voice is altered, the hearing is rendered dull, and the inflammation of the soft palate impedes deglutition. Yet on the whole the progress is slow, and there is little accompanying disorder of the general system. . . This species of sore throat often attends tubercular eruptions on the skm. There is reason to suppose that the secretion of the tonsils is analagous to that of the sebaceous glands of the skin, and hence it naturally happens that both parts are attacked simultaneously. 3. Venereal sores often commence on the surface of the mucous membrane, by a small foul ulceration, which passes at an early period into rapid and extensive sloughincr. These ulcers are not limited to the membrane covering the tonsils, but may arise on the soft palate, or any part of the pharynx, and are most frequently found immediately behind one of the posterior arches, or at the upper and back part of the pharynx, where the early appearance is concealed by the velum pendulum and uvula. They are sometimes preceded and a ways accompanied by much pain and inflammation. The soft palate is swelled and very pendulous, and the attempt to raise it in swallowing is attended with excruciating Sain. In speaking it seems to be absolutely quiescent. The irritation of the Tumid velum and the slough excites a profuse secretion of saliva, and frequently much cough. The great distress which is thus occasioned produces a remarkable anxiety of countenance, which, conjoined with rapid emaciation, an accelerated pulse, and expectoration of a puriform character, gives the patient the aspect of considerable danger, and often suggests the idea that he "J^W™*" phthisis. The ravages committed by these ulcers are very extensive. The bone at the back part of The nares is frequently laid bare, and the(^ase proceeds to the destruction of the nose : and it occasionally occurs that the bodies of the vertebra are exposed, and affected with fatal caries. ovton(i At other times especially in cases of long standing, these "^ *dl «tend not bv slouehino-, but by rapid ulceration. The aspect is less formidable, but Te CIf is Scarcely less destructive. This variety is most commonly seen on thPesgoft palate. ThJ surface is foul, but the slough which> occupies, ,, ,s,oi little depth. The sore is edged by a very narrow fringe of yellow slough, and b yond£ for the extent of a quarter of an inch, there is «. mflame- «n. Pn of a deep crimson colour; but there is not much general swelling of the sur rounK parte Yet the sore extends daily with extraordinary rapidity. The substanfeof he part seems to meltaway under the ulceration and the greater part

name of ™»1™™™ «*™*"}0£'™°^ This appearance sometimes supervenes by the opake white colour of the surtace- *"' freVuentiv there is no ulceration, at the edges of an ulcer on *** °^ but simply this chang^ as it were, of excoriation ot the ne superficial affection may attack brane, much soreness, but very 1 tie, pain. ^ and uvula, and even any part of the tonsils arche of thPa a\™u™;P f 't, t0 be seen at the

angles of the mou th.It o ten o P ^ ^.^ ance may be

Z^^W*^*™"™ C'dUSUC' 3nd lhen lheSUrfaR6benealh l0°k3 "Th^mplaint very often accompanies psoriasis of the skin, and it is reason- 208 HUNTER ON THE VENEREAL DISEASE. They are generally more painful than those of the skin, although not so much so as common sore throats arising from inflamed tonsils. They oblige the person to speak thick, or as if his tongue was too large for his mouth, with a small degree of snuffling. These are the most common symptoms of this stage of the disease, but it is perhaps impossible to know all the symptoms this poison produces when in the constitution. I knew a gentleman who had a teasing cough which he imputed to it; for it came on with the symptomatic fever, and continued with it, and by using mercury both disappeared. There are inflammations of the eyes which are supposed to be venereal; for after the usual remedies against inflammation have been tried in vain, mercury has been given, on the supposition of the case being venereal, and sometimes with success, which has tended to establish this opinion. But if such cases are venereal, the disease is very different from what it is when attacking other parts from the constitution, for the inflammation is more painful than in venereal inflammation proceeding from the constitution; and I have never seen such cases attended with ulceaagon, as in the mouth, throat, and tongue, which makes me doubt much of their being venereal.*

able to suppose that the white colour which peculiarly characterizes it implies a change analogous to that which shows itself on the surface of the body in thickening of the cuticle and scaliness. The author seems to be of opinion that this affection is never venereal; but cases occur where it exists in union with other venereal symptoms, and where it is only ultimately cured by the use of mercury. Yet it cannot be denied, that in the majority of cases it is not venereal ; that very often mercury ao-oravates instead of removing it; that it may take place where there is no suspicion of syphilis, in patients labouring under psoriasis or lepra; and that in general the presumption is so far against its venereal origin that the treatment should be rather directed to the regulation of the diet, and to the prevention of acid secretions in the stomach, than to the extirpation of the venereal virus. The complaint is in this respect also analogous to scaly diseases of the skin. Both affections depend most usually on causes which are not syphilitic ; nor do there appear to be any signs in the aspect of either by which the syphilitic can be distinguished from the non-syphilitic cases. ° -. There are other forms of sore throat which are less important, and of which it is less easy to convey an idea by description.] * [The author has here been mislead, either by the general principle which he imagined he had discovered, and which may be shown to be in many instances ZZlTf ?Z bytheTw.ant0/k°PP"^nity for a more extended observation of disease of the eye. It is established beyond the possibility of doubt, that iritis s frequently a secondary symptom of the venereal disease. The general symp tomsof iritis are well known. The distinctive signs of syphilitic irftfc lav£ ^SiSln^^SiM1 °lTSeS °f]k^ °f 3 -ddiroVbr^S

vlne^^ OF THE SYMPTOMS OF THE LUES VENEREA. 269 § 2. Experiments made to ascertain the Progress and Effects of the Venereal Poison.

To ascertain several facts relative to the venereal disease, the following experiments were made. They were begun in May 1767. Two punctures were made on the penis with a lancet dipped in venereal matter from a gonorrhoea ; one puncture was on the glans, the other on the prepuce. This was on a Friday; on the Sunday following Ihere was a teasing itching in those parts, which lasted till the Tuesday following. In the meantime, these parts being often examined, there seemed to be a greater redness and moisture than usual, which was imputed to the parts being rubbed. Upon the Tuesday morning the parts of the prepuce where the puncture had been made were redder, thickened, and had formed a speck; by the Tuesday following the speck had increased, and discharged some matter, and there seemed to be a little pouting of the lips of the urethra, also a sensation in it in making water, so that a discharge was expected from it. The speck was now touched with lunar caustic, and afterwards dressed with calomel ointment. Cn Saturday morning the slough came off, and it was again touched, and another slough came off on the Monday following. The preceding night the glans had itched a good deal, and on Tuesday a white speck was observed where the puncture had been made; this speck, when examined, was found to be a pimple full of yellowish matter. This was now touched with the caustic, and dressed as the former. On the Wednesday the sore on the prepuce was yellow, and therefore was again touched with caustic. On the Friday both sloughs came off, and the sore on the prepuce looked red, and its basis not so hard ; but on the Saturday it did not look quite so well, and was touched again, and when that went off it was allowed to heal, as also the other, which left a dent in the glans. This dent on the glans was filled up in some months, but for a considerable time it had a bluish cast. Four months afterwards the chancre on the prepuce broke out again, and very stimulating applications were tried; but these seemed not to agree with it, and nothing being applied, it healed up. This it did several times afterwards, but always healed up without any application to it. That on the glans never did break out, and herein also it differed from the other. While the sores remained on the prepuce and glans a swelling took place in one of the glands of the right groin. I had for some time "concdved an idea That the most effectual way to put back a bubo was to rub in mercury on that leg and thigh; that thus a current of mercury would pass through the inflamed gland. Here w^s a good opportunity of making the experiment. I had often rUccee§ed in this way, but now wanted to put it more critically to 24 270 HUNTER ON THE VENEREAL DISEASE. the test.* The sores upon the penis were healed before the reduction of the bubo was attempted. A few days after beginning the mercury in this method the gland subsided considerably. It was then left off, for the intention was not to cure it completely at present. The gland some time after began to swell again, and as much mercury was rubbed in as appeared to be sufficient for the entire reduction of the gland ; but it was meant to do no more than to cure the gland locally, without giving enough to prevent the constitution from being contaminated. About two months after the last attack of the bubo, a little sharp pricking pain was felt in one of the tonsils in swallowing anything, and on inspection a small ulcer was found, which was allowed to go on till the nature of it was ascertained, and then recourse was had to mercury. The mercury was thrown in by the same leg and thigh as before, to secure the gland more effectually, although that was not now probably necessary. As soon as the ulcer was skinned over the mercury was left off, it not being intended to destroy the poison, but to observe what parts it would next affect. About three months after, copper-coloured blotches broke out on the skin, and the former ulcer returned in the tonsil. Mercury was now applied the second time for those effects of the poison upon the constitution, but still only with a view to palliate. It was left off a second time, and the attention was given to mark where it would break out next; but it returned again in the same parts. It not appearing that any further knowledge was to be procured by only palliating the disease a fourth time in the tonsil, and a third time in the skin, mercury was now taken in a sufficient quantity, and for a proper time, to complete the cure. The time the experiments took up, from the first insertion to the complete cure, was about three years. The above case is only uncommon in the mode of contracting the disease, and the particular views with which some parts of the treatment were directed ; but as it was meant to prove many things which, though not uncommon, are yet not attended to, attention was paid to all the circumstances. It proves many things, and opens a field for further conjectures. It proves, first, that matter from a gonorrhoea will produce chancres. It makes it probable that the glans does not admit the venereal irritation so quickly as the prepuce. The chancre on the prepuce inflamed and suppurated in somewhat more than three days, and that on the glans in about ten. This is probably the reason why the glans did not throw off its sloughs so soon. It renders it highly probable that to apply mercury to the legs and thighs is the best method of resolving a bubo; and therefore * The practice in 1767 was to apply a mercurial plaster on the part, or to rub in mercurial ointment on the part, which could hardly act by any other power than sympathy. OF THE SYMPTOMS OF THE LUES VENEREA. 271 also the best method of applying mercury to assist in the cure, even when the bubo suppurates. It also shows that buboes may be resolved in this way, and yet the constitution not be safe; and therefore that more mercury should be thrown in, especially in cases of easy resolution, than what simply resolves the bubo. It shows that parts may be contaminated, and may have the poison kept dormant in them while under a course of mercury for other symptoms, but break out afterwards. It also shows that the poison having originally only contaminated certain parts, when not only completely cured, can break out again only in these parts.*

§ 3. Of the Symptoms of the Second Stage of the Lues Venerea.

This stage of the disease is not so well marked as the former; and, as it is of more importance, it requires all our discernment to determine what the disease is. The parts less susceptible of this irritation are such as are more out of the way of the great exciting cause, which is the external air, as has been before related. And they begin to take on the venereal action whether it may or it may not have produced its local effects upon the external or exposed surfaces; and they even go on with the action, in many cases, after these surfaces first affected have taken on the action and have been cured, as has been already observed. These deeper-seated parts are the periosteum, tendons, fascia?, and ligaments; however, what the parts affected may be when the disease is in this stage is not always certain: I have known it produce total deafness, and some of those cases to end in suppuration, attended with great pain in the ear and side of the head. Such cases are generally supposed to arise from some other cause ; and nothing but some particular circumstance in the history of the case, or some symptom attending it, can lead the surgeon to the nature of the complaint." When these deeper-seated parts become irritated by this poison the progress is more gradual than in the first: they have very much the character of scrofulous swellings or chronic rheumatism, only in this disease the joints are not so subject to it as they are m the rheumatism. We shall find a swelling come upon a bone when there has been no possible means of catching the infection for many months and it will be of some size before it is taken notice of, from ha Jig'givenbuT little pain. On the other hand there shall be great pain, !nd probably no swelling to be observed till some time after.

» re? «u„ „«t„ *t n 27. If the experiment had been made by one less [See the note at p. Jil^ V of the cage wou]d ,ea(] practised and ^f.^Xe^enereal virus had been conveyed to the punctures by to the •«P»«°° ^^rXh they were repeatedly touched. Certainly the

in common chancre.] 272 HUNTER ON THE VENEREAL DISEASE. The same observations are applicable to the swelling of tendons, and fasciae. As these swellings increase by slow degrees, they show but little signs of inflammation. When they attack the periosteum the swelling has all the appearance of a swelling of the bone, by being firm and closely connected with it. The inflammation produced in these later stages of the disease can hardly get beyond the adhesive, in which state it continues growing worse and worse, and when matter is formed it is not true pus but a slimy matter. This may arise in some degree from the nature of the parts not being in themselves easily made to suppurate ; and when they do suppurate the same languidness still continues, insomuch that this matter is not capable of giving the extraneous stimulus, so as to excite true suppuration or ulceration, even after the constitution is cleared of the original cause, and then the disease is probably scrofulous. Some nodes, either in the tendons or bones, last for years before they form any matter at all; and in this case it is doubtful whether they are venereal or not, although commonly supposed to be so. I have already observed that the pain in the first stages of this disease is much less than might be expected, considering the effects produced by the poison. The disease being very slow and gradual in its progress, its giving little pain may be accounted for. An ulcer in the throat causes no great pain; and the same may be said of blotches on the skin, even when they become large sores. When the periosteum and bones become affected the pain is sometimes very considerable, and at other times there is hardly any. It is not perhaps easy to account for this. We know also that the tendinous parts, when inflamed, give in some cases very considerable pain, and that of the heavy kind, while in others they will swell considerably without giving any pain. These pains are commonly periodical, or have their exacerbations, being commonly worst in the night. This is common to other aches or pains, especially of the rheumatic kind, which the venereal pains resemble very much. When the pain is the first symptom, it affords no distinguishing mark of the disease; it is therefore often taken for the rheumatism.*

* [Venereal affections of the bones are of different kinds. 1. Simple inflammation of the periosteum, which is marked by thickening of the periosteum, with much pain and tenderness, and usually terminates in the deposit of osseous matter beneath it, and the permanent enlargement of the bone. Sometimes, though more rarely, the periosteum suppurates, and then it often happens that a portion of the bone beneath it dies and exfoliates. This constitutes the most common venereal node, and is frequent on the tibia, the ulna, and the cranium. 2. Caries of the bone, which commences in the cancellous structure and gradually perforates the external plate; and then appears as a soft tumour, which may be seen and felt externally, If this tumour is laid open, a glairy fluid is evacuated; the periosteum is found to be somewhat thickened, and the bone beneath is denuded, and in the centre of the denuded part is found a small hole, OF THE SYMPTOMS OF THE LUES VENEREA. 273 § 4. Of the Effects of the Poison on the Constitution.

The poisonous matter, simply as extraneous matter, produces no change whatever upon the constitution, and whatever effects it has depend wholly upon its specific quality as a poison. The general effects of this poison on the constitution are similar to other irritations, either local or constitutional. It produces fever, which is of the slow kind; and when it continues a considerable time it produces what is called a hectic disposition, which is no more than an habitual slow fever arising from a cause which the constitution cannot overcome. While this exists it is impossible that anything salutary can go on in such a constitution. The patient loses his appetite, or even if his appetite is good, loses his flesh, becomes restless, loses his sleep, and looks sallow.* In the first stage of this disease, before it begins to show itself externally, the patient has generally rigors, hot fits, headaches, and all the symptoms of an approaching fever. These symptoms continuing for some days, and often for weeks, show that there is some irritating cause which works slowly upon the constitution. It is then supposed to be whatever the invention or ingenuity of the practitioner shall call it; but the venereal eruptions or nodes upon either the periosteum, bones, tendons, or other parts appearing, show the cause, and in some degree carry off the symptoms of fever and relieve the constitution for a little time, but they soon recur. These constitutional complaints, however, are not always to be found, the poison stimulating so slowly as hardly to affect the constitution, unless it be allowed to remain in it a long time. There are a number of local appearances, mentioned by authors, which I never saw, such as the fissures about the anus, &c. There are also a number of diseases described by authors as venereal,

which perforates the cortical plate, and communicates with the interior of the bone. This affection is very common in the skull, and may be occasionally seen in the tibia, the jaw, and the ulna. It constitutes in its aggravated forms the worm-eaten caries, which is sometimes seen to pervade extensively the bones of the cranium. . . 3. There is, less frequently, a third form of disease, which seems to be originally simple inflammation of the bone, and which is most commonly seen in the skull. The thickness of the bone is greatly increased, and the structure becomes dense and ponderous. The periosteum is for the most part unaltered; but during the course of the disease it is often attacked by inflammation at particular points, and then it rises into small nodes. These nodes generally subside again in a week or two, when similar enlargements occur elsewhere, and usually in like manner disappear in their turn. Sometimes, however, instead of subsiding, they suppurate, and the surface of the bone becomes carious. Yet no considerable portion dies and separates : the ulcer does not spread, but after a certain lapse of time heals a^ain, leaving the surface of the bone uneven, and the cicatrix closely adhering to ft. The enlargement of the bone subsides on the cure of the disease, except in cases where the disease has been of very long continuance.] * This kind of look, although arising entirely from a harassed constitution, is always supposed to be peculiar to a venereal one. This idea, however, does not arise from the look only, but from the leading symptoms. 24* 274 HUNTER ON THE VENEREAL DISEASE. especially by Astruc and his followers, which are almost endless. The cancer, scrofula, rheumatism, and gout have been considered as arising from it, which may be in some measure true; but they are with them the disease itself, and all their consequences, as consumption, wasting from want of nourishment, jaundice, and a thousand other diseases, which happened many years before the existence of the lues venerea, are all attributed to it. There is even at this day hardly any disease the practitioner is puzzled about, but the venereal comes immediately into his mind ; and if this became the cause of careful investigation it would be productive of good, but with many the idea alone satisfies the mind. CHAPTER III.

GENERAL OBSERVATIONS ON THE CURE OF LUES VENEREA.

It has been observed before, that there are three forms of the venereal infection, gonorrhoea, chancre, and the lues venerea, which various forms I have endeavoured to account for. As they all three arise from the same poison, and as the two first depend only on a difference in the nature of the parts, and the lues venerea on another circumstance which has been explained, it would be natural to suppose that one medicine, whatever it be, would cure all the forms of this disease. But we find from experience that this does not hold good; for one medicine, that is mercury, cures only the chancre and the lues venerea, and the gonorrhoea is not in the least affected by it; and what is still more remarkable is, that the two which it cures are in no respect similar, while the gonorrhoea, which it does not cure, is similar in some respects to the chancre, which it does cure. It may be remarked in general, that there is not only a difference in the form of the disease, but also in the modes of cure, and in the times necessary for the cure of the different forms of the disease, even when the same medicines cure. The gonorrhoea, in its cure, is the most uncertain of the three, the chancre next, and the lues venerea the most certain, although cured by the same medicine which cures the chancre. A gonorrhoea in some cases shall be cured in six days, and in others require as many months, which, with regard to time, is about the proportion of thirty to one. A chancre may be sometimes cured in two weeks, and often requires as many months, which is in the proportion of four to one. The lues venerea in general may be cured in one or two months, which is only two to one. This calculation shows the regularity and irregularity, as to time, in the cure of each form of the disease. I have formerly observed, that indispositions of the body often ON THE CURE OF THE LUES VENEREA. 275 affect this disease very considerably, more especially the gonorrhoea and the chancre. When an increase of symptoms takes place in a gonorrhoea, from an indisposition of body, nothing should be done for the gonorrhoea, the indisposition of body being only to be attended to; because we have no specific for the gonorrhoea, and in time it cures itself. But this practice is perhaps not to be followed in a chancre or lues venerea. It may be necessary in those to continue the mercury, although perhaps more gently; for the mercury is a specific that cannot be dispensed with, because neither the chancre nor lues venerea are cured by themselves, but always increase. This form of the venereal disease I have divided into two stages. When in the parts most susceptible of the disease, which I have called the first order of parts, and which appear to be the superficies only, the lues venerea is perhaps subject to less variety than either the gonorrhoea or chancre, and its mode of cure is of course more uniform, although the disease be less easily ascertained, at least for some time. In the second order of parts the lues venerea becomes more complicated, and its cure still less to be depended upon. . The cure of this form is much more difficultly ascertained than either of the two former: they, being always local, and their effects visible, become more the object of our senses, so that we are seldom or never deceived in the cure, although at the same time the cure is often more tedious and difficult; for whenever the symptoms of the gonorrhoea or chancre have entirely disappeared, in general the patient may look upon himself as cured of them ; but this is not the case in the lues venerea. m A lues venerea is the effects of the poison having circulated in the blood till it has irritated parts so as to give them a venereal disposition, which parts sooner or later assume the venereal action, according to the order of their susceptibility. When the venereal matter is circulating I have supposed that certain parts are irritated by it, and that a vast number of other parts escape, as is evidently the case with the chancre ; for in the case of a chancre the whole glans, prepuce, and skin of the penis have had the matter applied to them, yet only one or more points are contaminated or irritated by it, all the others escaping; and we often see in the lues venerea, that when the parts contaminated assume the action, it is confined to them without affecting other parts, although the disease be allowed to go on for a considerable time without any attempt to a cure; and also, if these parts are imperfectly cured, the disease returns only in them; therefore these effects although arising from the constitution, are in themselves entirelv local, similar to the gonorrhoea and chancre, and like them mav be cured locally; and the person may still continue to have the lues venerea, although not in these, yet in other parts, because there may be many other parts in the same body that are under the venereal disposition, although they may not yet have assumed the 276 HUNTER ON THE VENEREAL DISEASE. venereal action. To cure the local and visible effects of the disease we must attack it through that medium by which it was communicated, that is, the blood ; without, however, considering the blood itself as diseased or containing the poison, but as the vehicle of our medicine which will be carried by it to every part of the body where the poison was carried, and in its course it will act upon the diseased solids. This practice must be continued some time after all symptoms have disappeared; for the venereal action may to appearance be stopped, and symptoms disappear, and yet all return again, the venereal action not being completely destroyed. If the medicine were also a cure for the disposition in the parts second in order, and could prevent their coming into action, it would be necessary to continue it somewhat longer on their account; but this is not the case, for the visible effects, symptoms, or appearances in the first order of parts, give way to the treatment, while the parts that have only acquired the disposition, and are still inactive, afterwards assume the action and continue the disease. This deceives the surgeon, and leaves the groundwork for a second set of local effects in the parts second in order; but I have asserted that what will cure an action will not cure a disposition ; if so, we should push our medicine no further than the cure of the visible effects of the poison, and allow whatever parts may be contaminated to come into action afterwards. The parts that first assume the venereal action are easiest of cure; and I have suspected that those effects of the disease being external, were in some degree assisted in their cure by the local action of the medicine, which evidently passes off through those parts. When the disease has attacked the parts second in order of susceptibility, it generally happens that they are more difficult of cure than the former; therefore when they are affected at the same time with the former, and are cured, we may be sure that the first will be also cured. From hence, as it would appear that the parts most susceptible of the disease are also easiest of cure, it follows that the parts least susceptible of the disease are also most difficult of cure ; and I believe that this is seldom or never reversed ; therefore those second in order of susceptibility have this advantage, that we have the local complaints for our guide to judge of the whole; and in such we have only to continue the treatment till they all vanish, being certain that the cure of the first, if there are any, will be involved in those of the second. As the second are attended with more tumefaction or swelling than the first, it becomes a question whether the mercurial course should be continued till the whole has subsided. But I believe it is not necessary to continue the method of cure till the whole tumefaction disappears, for as those local complaints cannot conlaminate the constitution by reabsorption, and as the venereal disposition and action from the constitution can be cured while the local effects still remain, even where the tumefaction forming nodes on the bones, ON THE CURE OF THE LUES VENEREA. 277

fascise, &c. is carried the length of suppuration, there can be no occasion for continuing the course longer than the destruction of the venereal action. But this effect of our medicine is not easily known; therefore it will be necessary to pursue the method of cure till the appearances become stationary, and probably a little longer to destroy the whole action of the disease. From these circumstances it would appear that the venereal irritation, when in this stage of the disease, is easier of cure than the effects of that irritation, such as the tumefaction.

§ 1. Of the Use of Mercury in the Cure of the Lues Venerea.

Mercury in the lues venerea, as in the chancre, is the great specific, and hardly anything else is to be depended upon. It is necessary that we should always consider well the effects of this medicine, both on the constitution at large and the disease for which it is given. The effects of mercury on a constitution will always be as the quantity of mercury in that constitution; and when the same quantity affects one constitution more than another, it is in the proportion of the irritability of that constitution to the powers of mercury, entirely independent of any particular preparation, or any particular mode of giving it. With regard to the preparations of the medicine, and the modes of applying it, we are to consider two things ; first, the preparation and mode that is attended with the least trouble or inconvenience to the patient; and second, the preparation and mode of administering it that most readily conveys the necessary quantity into the constitution. Nothing can show more the ungrateful or unsettled mind of man than his treatment of this medicine. If there is such a thing as a specific, mercury is one for the venereal disease in two of its forms; yet mankind are in pursuit of other specifics for the disease, as if specifics were more common than diseases; while at the same time they are too often contented with the common mode of treating many other diseases for which they have no specific; and these prejudices are supported by the public, who have in their minds a dread of this medicine, arising from the want of knowledge of our predecessors in administering it; and many of the present age, who are equally ignorant, take advantage of this weakness. Mercury in the constitution acts on all parts of the machine, cures those which are diseased, affecting but little those that are sound. Mercury is carried into the constitution in the same way as other substances, either externally by the skin, or internally by the mouth: it cannot, however, in all cases, be taken into the constitution in both ways, for sometimes it happens that the absorbents on the skin will not readily receive it, at least no effect will be produced, either on the disease or constitution, from such application; when this is the case it is to be considered as a misfortune, for then it must be given internally by the mouth, although possibly this 278 HUNTER ON THE VENEREAL DISEASE. mode may be very improper in other respects, and often inconvenient. On'the other hand, it sometimes happens that the internal absorbents will not take up this medicine, or at least no effect is produced either upon the disease or constitution; in such cases it is right to try all the different preparations of the medicine, for it will sometimes happen that one preparation will succeed when another will not. I have never seen a case where neither external nor internal applications of mercury were absorbed; such a case must be miserable indeed. 1 may just observe here, that many surfaces appear to absorb this medicine better than others, and most probably all internal surfaces and sores are of this kind; for when we find that thirty grains of calomel rubbed in on the skin has no more effect than three or four taken by the mouth, it becomes a kind of proof that the bowels absorb it best; also, when dressing a small sore with red precipitate produces a salivation, it shows that sores are good absorbing surfaces, especially too when we know that the lues venerea generally arises from a chancre. A patient with a stump which produced too much granulation was dressed with ointment containing a large proportion of red precipitate ; the sore was about the size of a crown piece. It very nearly brought on a salivation, and the patient was obliged to leave it off. A mulatto woman had upon her leg a very bad ulcer, which was about the breadth of two palms; it was dressed with red precipitate mixed with common ointment, which soon threw her into a violent salivation. A lady, in the month of December 1782, was burnt over the whole breast, neck, and shoulders, as also between her shoulders, on which parts deep sloughs were formed. The sores at first healed nearly up, and tolerably well for burns; but they broke out anew and then became more obstinate. Seven months after the accident she came to London, with very large sores extending across the breast and upon each side to the shoulders; they were extremely tender and painful. They continued to heal for some time after she came to London; but she became ill, having been affected with extreme irritability, loss of appetite, sickness, and throwing up of her food and medicines. At this time the sores again began to spread, and became very large. After having been two months in town with little advantage, I tried warmer dressings, as basilicon, to some parts, to see if any advantage would arise from such treatment, and it was found that these parts healed rather faster than the others; but the soreness was so great, even from the mildest dressings, that they could only be used in part. I next tried red precipitate mixed with the ointment; and, that it might increase the pain as little as possible, I ordered only ten grains to two ounces of the ointment. This appeared to agree better with the sores than the ointment alone ; and we were happy in having found a dressing, which both hastened on the cure and was easier than the former. ON THE CURE OF THE LUES VENEREA. 279 But about the fourth or fifth dressing from beginning the use of the precipitate, she began to complain of her gums; the next day began to spit, and by the seventh or eighth day the mouth was so sore, and the spitting so considerable that, upon considering the case, we began to suspect that it might proceed from the red precipitate in the dressing. The gums, inside of the cheeks, and the breath were truly mercurial. We immediately left off this dressing, except to a small corner, and had recourse to the former dressings. In a few days the effects of the mercury abated, and the sores looked more healthy than ever, and we again began to dress part of the sores with the ointment containing precipitate, which still agreed with them. When the mouth first became affected she had not used much above one half of the ointment; and by the time we had discovered the cause, about three fourths of it had been expended in dressings, so that there was not quite ten grains of precipitate applied; and although this took up seven or eight days, and the ointment must have been soon removed from the sore by the discharge, yet a considerable spitting was produced, which lasted above a month. It is hardly to be conceived that above a grain or two could really be taken into the constitution; for when we consider the particles of precipitate were covered with ointment, and a vast discharge of matter, so as soon to remove this small quantity from the sore, we can hardly admit the possibility of more being absorbed ; and if this idea of the quantity taken in is just, to what must we attribute the great susceptibility to the effects of the medicine? Was it the irritable state of the patient at the time? For the state of the constitution appeared to me to be that in which the locked jaw often takes place; and I often had this disease in my mind. The patient afterwards got well by the use of an ointment in which pitch was an ingredient.* All this tends to show that sores and internal surfaces absorb better than the skin. Besides the practicability of getting the medicine into the constitution in either way, it is proper to consider the easiest for the patient, each mode having its convenience and inconvenience, which arise from the nature of the constitution or of the parts to which it is applied, or from certain situations of life of the patient at the time. It is therefore proper to give it in that way which suits these circumstances best. To explain this further, we find that in many patients the bowels can hardly bear mercury at all, therefore it is to be given in the mildest form possible ; also joined with such other medicines as will lesson or correct its violent local effects, although not its specific ones on the constitution at large. When it can be thrown into the constitution with propriety by the external method, it is preferable to the internal, because the skin is not nearly so essential to life as the stomach, and therefore is * Added : " A gentleman introduced a bougie into the urethra smeared with mercurial ointment, and rubbed in a little on the frajnum three times, and his mouth became affected."—Home. 280 HUNTER ON THE VENEREAL DISEASE. capable in itself of bearing much more than the stomach; it also affects the constitution much less; many courses of mercury, which are absolutely necessary, would kill the patient if taken by the stomach, proving hurtful both to the stomach and intestines, even when given in any form, and joined with the greatest correctors: on the other hand, the way of life will often not allow it to be applied externally. It is not every one that can find convenience to rub in mercury, therefore they must take it by the mouth if possible. To obviate the inconvenience often arising from the visible effects of mercury, many preparations have been invented; but any preparation of mercury producing an effect different from the simple effects of mercury in that constitution, such as sweating, or an increased discharge of urine, must be supposed either not to act as mercury, or the substance with which it is compounded produces this effect; but if its peculiar effects are less than usual, I should very much suspect that the mercury is acting in part as a compound, and not entirely as mercury. Mercury, like many other medicines, has two effects, one upon the constitution and particular parts, which is according to its mode of irritation, independent of any disease whatever. The other is its specific effects upon a diseased action of the whole body, or of parts, whatever the disease be, and which effects are only known by the disease gradually disappearing. The first becomes an object of consideration for the surgeon, as it is in some measure by them he is to be guided in giving this medicine so as to have its specific effects sufficient for the cure of the disease. Whatever injury mercury may do to the constitution it is by its visible effects, and thence the pretended art ki avoiding those visible effects has been too much the cause of great imposition. The part upon which its effects are most likely to fall is the part that is in most cases attempted to be avoided, or guarded against, and that is the mouth. I believe that we are not possessed of any means of either driving the mercury to the mouth, or of preventing it from attacking that part. Cold and warmth are the two great agents mentioned by authors: we find them recommending the avoiding of cold, for fear the mercury should fly to the mouth, as if warmth was a prevention; while others, and even the same authors, when talking of bringing the mercury to the mouth, recommend warmth, as if cold were a preventive. This being the case, we may reasonably suppose that neither the one nor the other has any material effect.* In giving mercury in the venereal disease the first attention should be to the quantity, and its visible effects in a given time; which when brought to a pitch are only tq be kept up, and the decline of the disease to be watched ; for by this we judge of the invisible or specific effects of the medicine, which will often inform us that some variation in the quantity may be necessary. The visible effects of mercury are of two kinds, the one on the * The whole of this paragraph omitted.—Home. ON THE CURE OF THE LUES VENEREA. 261 constitution, the other on some parts capable of secretion. In the first it appears to produce universal irritability, making it more susceptible of all impressions; it quickens the pulse, also increases its hardness, producing a kind of temporary fever; but in many constitutions it exceeds this, acting as it were as a poison. In some it produces a kind of hectic fever, that is, a small quick pulse, loss of appetite, restlessness, want of sleep, and a sallow complexion, with a number of consequent symptoms; but by the patient being a little accustomed to the use of it these constitutional effects commonly become less, of which the following cases are strong instances. A gentleman rubbed in mercurial ointment for the reduction of two buboes. He had only rubbed in a few times when it effected his constitution so much that it was necessary to leave it off. He was seized with feverish complaints of the hectic kind, a small quick pulse, debility, loss of appetite, no sleep, and night sweats. He took the bark, with James's powder, and asses' milk, and got gradually rid of the complaints. As the buboes were advancing, it was necessary to have recourse to mercury again ; and I told him that now it would not produce the same effects so quickly nor so violently as before. He rubbed in a considerable quantity without his constitution or mouth being affected; but the buboes suppurating, I ordered it to be left off a second time; and when they were opened he had recourse to the ointment again for the third time, and without producing any disagreeable effects. Ihe buboes put on a healing disposition for a while, and then became stationary, showing that a new disposition was forming. He was directed to leave off the ointment and to bathe in the sea, which he did, and the buboes began to heal. In about three weeks, however, it was thought necessary to use more friction, and when he began, which was the fourth time, it had almost an immediate and violent effect upon his mouth; he left off again till his mouth became a litt e better, and then returned to the mercury a fifth time, and was able to go on with it. . . . , , .,, .. A stout healthy man used mercurial friction for a bubo till it affected his mouth; it further brought on very disagreeable.constitutional complaints, such as loss of appetite, watchfulness, sallow coZlexion lassitude from the least exercise, and swelled legs; and ^t^^Zn^ns were used to reconcile the constitution to it vet it continued to act as a poison. ffercury often produces pains like those of the rheumatism and alsonodesywhich are of a scrofulous nature: from thence it has been aVcu-Jd of affecting the bones, «lurking in them," as authors have expressed it.*

: &?^ pss1! «£#••» *■».» «* ~"—,hat ,hey can hardly bear it. notaiways affect the mouth, yet it sometimes affects 282 HUNTER ON THE VENEREAL DISEASE. It may be supposed to be unnecessary to mention, in the present state of our knowledge, that it never gets into the bones in the form of a metal, although this has been asserted by men of eminence and authority in the profession, and even the dissections of dead bodies have been brought in proof of it; but my experience in anatomy has convinced me that such appearances never occur. 1 hose authors have been quoted by others, imaginary cases of disease have been increased, the credulous and ignorant practitioner misled, and patients rendered miserable.*

appetite, pains of the rheumatic kind, and all the constitutional symptoms of hectic fever; and at the same time shall be curing the venereal disease effectually. A person had pains in his shoulders and blotches on the skin, supposed to dim,T »" never.c?uld be aff<*ted with mercury. I made him rub in two drams of strong mercurial ointment every night, and the symptoms entirely dis- SSi's^l"7 efFCCtS bdng Pr°dUCe<i' b* the "—J °" the -outh7skin, effC JJJf SymPtoms whfich ™rk what the author has denominated the poisonous don ThevT^ aretofs"ch importance as to require a more particular^ descrip! ro^ic^ctr6 ^ ^^ ^ ^ 0"e ^ a" acute' the •*« ■ PffS.enf°fhT C-°nSthu[es whka.1 h™}>fen denominated mercurial erethismus. The effect of the poison is here chiefly felt on the heart. The pulse becomes hurried small, and irregular; the action of the heart violent, but at th?™ tim? ir! 3ie%^e?bvrlS; a0d ^ r^^ 3nd imP^ction of the cSation are 11 ?1 by paleness of the countenance, by frequent sighing, and anxiety about the praecordia, and by unsteadiness of the limbs. In very severe cases he countenance becomes contracted, and the extremities cold. * Neverthele msteaTfn^11 ^7^ Sh°T n° S'%nS °f de^ngement, and the tongue though SSn Lddenlvmf^r' ? Clea"- U"der ^ circ^^ances muscular'exertion recover. J ynC°Pe e"SUeS' fr°m which the heart is to° weak to

heLftwillCr/ritdiT?tin-!led'and1properremedies are used>the action of the entYi]Tdi8ann?« ! ^ ^^ l0ne ™d ""^"ity, and the affection will entirely disappear, leaving no consequences behind it. it Jltr^f ^ the dera"gement may be less immediately dangerous, but it more extensively pervades the whole system, and is more permanent There

inflammation of the joints, having something of a scrofulous character The ulcerative will everywhere supersede the adhesive process Sl.Vht wounds wH form sores, and when fractured bones have recentfy united theudon willI give

Ye^re^ not easily corrected. often of an inordinate dose nf rnlZ . removed. It is the result not so long and obBtina^ewveineTX"^ C° 1"? 0nI* f°r a short Period' as of * standing eyldenZg^Z deterSrated h«hh I„H S" °- T^ * d°SeS' n°tWhh- The expression of th» a„?i! jj , . a,th and d'mimshed powers. the sameSbH.I1 J cu^'he llt^ ', J 8ubaernt ^^ that m^^ " a' as referring to the ab™^ effects of the remedy. Experience fSl v Kthe ^Xlstence of the poisonous altogether inconsistent wKZZni^^t '^ thfSe P°,isonous effects are in its use, after they have sUo^ZZ^^Tei^ ^p^tTE ON THE CURE OF THE LUES VENEREA. 283 § 2. Of the Quantity of Mercury necessary to be given.

The quantity of mercury to be thrown into the constitution for the cure of any venereal complaint must be proportioned to the violence of the disease. Two circumstances are, however, to be strictly attended to in the administration of this medicine; which are, the time in which any given quantity is to be thrown in, and the effects it has on some parts of the body, as the salivary glands, skin, or intestines. These two circumstances, taken together, are to guide us in the cure of the disease ; for mercury may be thrown into the same constitution in very different quantities so as to produce the same ultimate effect; but the two very different quantities must be also in different times. For instance, one ounce of mercurial ointment, used in two days, will have more effect upon the constitution than two ounces used in ten; and to produce the same effect in the ten days, it may perhaps be necessary to use three ounces or more. The effects on the constitution of one ounce used in two days are considerable, and also its effects upon the diseased parts; therefore a much less quantity in such a way will have greater effects. But if these effects are principally local, that is, upon the glands of the mouth, the constitution at large not being equally stimulated, the effect upon the diseased parts must also be less, which is to be determined by the local disease not giving way in proportion to the effects of the mercury on some particular part. If it is given in very small quantities, and increased gradually, so as to steal insensibly on the constitution, its visible effects are less, and it is hardly conceivable how much may at last be thrown in without having any visible effect at all.* These circumstances being known, it makes mercury a much more efficacious, manageable, and safe medicine than formerly it was thought to be; but unluckily its visible effects upon some particular parts, such as the mouth and the intestines, are sometimes much more violent than its general effect upon the constitution at laree ; therefore a certain degree of caution is necessary not to stimulate these parts too quickly, as that will prevent the necessary

qUTte%orsti1u?ion"'or parts, are more susceptible of mercury at first than afterwards; if the mouth is made sore, and allowed to recover, a much greater quantity may be thrown in a second time, before the same soreness is produced ; and indeed I have seen cases where it could not be reproduced by as much mercury as possibly

minent danger, at the same time in no degree answers the object of the surgeon in the removal of the disease for v, ich i is g ven ] *7° ^Tcted a eenUema?sgmouth. The ointment was of equal part- of ten days, affected a gen«em» ^^ q{ omUU the ointmenl occasionally, mercury and hogs-iaro. , y ^^ .^ s every night for rlrn1S;nwifhouttavUrneg Ms mouth, or any of the secretions, visibly affected, 284 HUNTER ON THE VENEREAL DISEASE. could be thrown in. Upon a renewal of the course of mercury therefore the same precautions are not necessary as at first. We are, however, every now and then deceived by this medicine, it being hardly possible to produce visible effects at one lime; and afterwards the mouth and intestines shall all at once be affected. Mercury, when it falls on the mouth, produces in many constitutions violent inflammation, which sometimes terminates in mortification. The constitutions in which this happens I suspect are of the erysipelatous kind, or what are called the putrid ; therefore in such, greater caution is necessary. Mercury in general, that is, where it only produces its common effects, seldom or never does any injury to the constitution; it should seem only to act for the time, and to leave the constitution in a healthy state. But this is not always the case, for probably mercurv can be made to affect every constitution very materially, being capable of producing local diseases, as has been mentioned, and also capable of retarding the cure of chancres, buboes, and certain effects of the lues venerea after the poison has been destroyed.

§ 3. Of the sensible Effects of Mercury upon Parts.

The sensible effects of mercury are generally an increase of some of the secretions, a swelling in the salivary glands, and increase of saliva ; an increase of the secretion of the bowels, which produces purging and an increase of the secretion of the skin, producing sweat, also often an increase of the secretion of urine. Sometimes one of these secretions only is affected, sometimes more, and sometimes all of them together; but the effects upon the mouth are the most frequent. Mercury often produces headaches, and also costiveness, when of th^ mouth0 PartS beCOmes sensible> especially upon the glands

When the mercury falls upon the mouth, it does not affect all fhTX°L GTlyL sometime* stacking the gums, at other times the cheeks, which become thickened and ulcerlte, while the gums I" nf°Kv thG lea,? afftCtef as aPPears b^ the Patie»t being fapable of biting anything hard. & v Mercury, when it falls upon the mouth, and parts belonging to the mouth, not only increases the discharge of those parts, but it brings on great tumefaction, which is not oV the true inflammatory kind, where coagulable lymph is thrown out, but rather resembling erysipelatous tumefaction. The tongue, cheeks, and gums swe"f and the teeth become loose; all which effects are in pfop^rtioTto

or JuT&tSL'T17 fVen' 3nd —Polity of "he parS ior such irritation. It produces great weakness in the Darts in which ulceration easily takes pla?e, especially if thev are in C

when U fa„s on Cher parJX % &%*%, ™£.^ ON THE CURE OF THE LUES VENEREA. 285 cases, is generally ropy, as if principally from the glands affected. The breath acquires a particular smell.* As mercury generally produces evacuations, it was naturally imagined that it was by this means that it effected a cure of the venereal disease ; but experience has taught us that, in curing the venereal disease by this medicine, evacuations of any kind produced by it are not at all necessary. And this might have been supposed, as similar evacuations, produced by other medicines, are of no service; therefore it was reasonable to imagine that these evacuations when produced by mercury, were also of no service, except we could suppose that the evacuation produced by the mercury was not the same with that produced by other medicines, but that it was a specific evacuation; that is to say, a discharge carrying off the venereal poison by its union with the mercury, and therefore the faster the mercury went off the sooner would the poison be carried out of the constitution. But this is not found to be the case in practice: on the contrary, evacuations produced by the medicine retard the cure, especially if the secretory organs are too susceptible of this stimulus; for then the quantity which is necessary or sufficient for the cure of the disease cannot be taken in, the effects of the medicine upon particular parts being greater than the patient can bear; and the quantity of mercury to be thrown into the constitution must be limited and regulated according to the quantity of evacuation, and not according to the extent ot the disease. On the other hand, if it is given with care, so as to avoid violent evacuation, any quantity may be thrown in sufficient for the cure of the disease. Certain evacuations may be supposed to be a mark ot the constitutional effects of mercury, but they are not to be entirely depended upon, the secretions being only a proof of the susceptibility ot some parts to such a stimulus; however, it is probable that in general they are a good gauge of its constitutional effects. Some have gone so far as to suppose that quantity of mercury alone, without any sensible effects, is sufficient for the cure of the disease; and this is in some degree the case, but not completely so, for we have no good proof of its affecting the constitution but by its producino- an increase of some of the secretions.

§ 4. Of the Action of Mercury.

Mercury can have but two modes of action, one on the poison, theTether on the constitution: we can hardly suppose it to act both ways If mercury acted upon the poison only, it might be supposed to be in two ways, either by destroying its qualities by decompo-

* KAA»A- "Anerson could not have mercury applied externally without its * Added . " A Pe"J" JJ" • He could take ten or twelve grains of the occasioning yiolentinfl^mationnoQt ^ ^ ^^ ^ mouth> but lt rnercurius c^cJnat"StheJtehye c0*]d hardly walk ; and, to use his own expression, nStorkSv < whe^his head was Vor on.' ^Home. 286 HUNTER ON THE VENEREAL DISEASE. sing it, or by attracting it and carrying it out of the constitution. If the first were the action of mercury, then we might reasonably suppose that quantity alone would be the thing to be depended upon; if the second, that the quantity of evacuation would be the principal circumstance. But if it act upon the principle of destroying the diseased action of the living parts, counteracting the venereal irritation by producing another of a different kind, then neither quantity alone, nor evacuation, will avail much; but it will be quantity joined with sensible effects that will produce the quickest cure, which from experience we find to be the case. But although the effects that mercury has upon the venereal disease are in some degree in proportion to its local effects on some of the glands, or some particular part of the body, as the mouth, skin, kidneys and intestines, yet it is not exactly in this proportion, as has been mentioned. When mercury disagrees as it were constitutionally, producing great irritability and hectic symptoms, this action or irritation is not a counter-irritation to the venereal disease, but is a constitutional irritation having no effect on the disease, which continues to increase. Mercury, losing its effects upon the disease by use, gives a proof that it neither acts chemically, nor by carrying off the poison by evacuation, but by its stimulating power. The effects will always be in proportion to the quantity in a given time, joined with the susceptibility of the constitution to the mercurial irritation. These circumstances require the minutest attention ; and in order to procure its greatest action with safety, and to procure this in the most effectual way, it must be given till it produces local effects somewhere, but not too quickly, that we may be able to throw in a proper quantity; for local effects produced too quickly prevent the sufficient quantity being thrown in tor counteracting the venereal irritation at large. I have seen cases where the mercury very readily acted locally, and yet the constitution was hardly affected by it, for the disease did not give way. & A gentleman had a chancre which he destroyed with caustic, and dressed the sore with mercurial ointment. He had also a slight uneasiness in one of his groins, which went no further, but which showed an absorption of the poison. The chancre soon healed, and he rubbed in about two ounces of mercurial ointment. He began this course with small quantities, that is, a scruple at each rubbing, and increased it; however, it soon affected his mouth, and he sni

o0nreaof°b^t mTh' WTW° m°nths &fter he had a venereal ulcer^n smal? m,a t°t f G W3S ? considerable sensible effect from a S?e^ «?rCUT^hich Pr°Ved ineflfectual> because its specihc effects, as I apprehend, were not in proportion to its sene^,efSilhn:Sa"Varyglandstei^ "«> -3eePp,ih!e0nof0theSrr- On the other hand, I have seen cases where quantity did not answer, t.ll ,t was gtven so quickly as to affect thcTonstLlion7n ON THE CURE OF THE LUES VENEREA. 287 such a manner as to produce local irritation, and consequently sensible evacuations, which is a proof that the local effects are often the sign of its specific effects on the constitution at large, and shows that the susceptibility of the diseased parts to be affected by the medicine is in proportion to the effects of it upon the mouth. Its effects are not to be imputed to evacuation, but to its irritation; therefore mercury should be given, if possible, so as to produce sensible effects upon some parts of the body, and in the largest quantity of mercury that can be given to produce these effects within certain bounds; and these sensible effects should be the means of determining how far the medicine may be pushed, in order to have its best effects upon the disease without endangering the constitution. The practice here must vary according to circumstances ; and if the disease is in a violent degree, less regard must be had to the constitution, and the mercury is to be thrown in in larger quantities; but if the disease be mild it is not necessary to go beyond that rule, although it is better to keep up to it on purpose to cure the disease the sooner. # If the disease is in the first order of parts, a less quantity of mercury is necessary than if it were in the second order of parts, and had been of long standing, with its first appearances only cured, and the venereal disposition still remaining in the secondary parts, io cure the disease, whether in the form of chancre, bubo, or lues venerea, probably the same quantity of mercury is necessary, tor one sore requiresas much mercury as fifty sores m the same person, and a small sore as much as a large one; the only difference, if there is any, must depend upon the nature of the parts affected, whether naturally active or indolent. If there be any material difference between the recent and constitutional, which, I apprehend, there is, it may make a difference in the quantity. I do conceive that the recent are upon the whole more difficult to cure; at least they commonly require longer time, although not always. Having thus far premised these general rules and observations, I shall now give the different methods of administering mercury.

S 5. Of the different methods of giving Mercury - externally - " J internally.

Previously to the giving of mercury it is very proper to understand2 a^possible" the constitution of the patient with regaid to hrmedicine, which can only be known in those who have gf a 1 through a mercurial course; but as many of our itoSa^McStounde^o this treatment more than once, it patients are odii e s ^ ^^ ^ who can b becomes no vague inqury very proper that this

thu1S SGKlTnown as it w 11 be a direction for our present practice should ^ known a, it w11 ^ ^^ a]though T think that ^w co^ntu^ consideraDle quantity at one

the patient was affected with a very little. 288 HUNTER ON THE VENEREAL DISEASE. When mercury is given to cure the lues venerea, whatever length we mean to go in the sensible effects of it, we should get to that length, if possible, and we should keep up to it. For we shall find it difficult to bring its effects to that standard again if we allow it to get below it. If the mercury should get beyond what we intended, we should be very much upon our guard in lowering it, and should probably begin to give it again before its effects are reduced to the intended standard; for the same quantity now will not operate so powerfully as before, insomuch that what at first produced greater effects than was intended will not be sufficient afterwards. Mercury is best applied externally in form of an ointment Unctuous substances keep it divided, attach it to surfaces, and do not dry; it may also be supposed that they become a vehicle for the mercury, and carry it through the absorbents to the general circulation ; for it is probable that oil is as easy of absorption as watery substances. r If the symptoms are mild in the first order of parts, and the patient not accustomed to mercury, or it is known that he cannot bear the medicine in great quantity, and it is intended to conduct tne cure by almost insensible means, it is proper to begin with small quantities. One scruple, or half a drachm, of an ointment made of equal parts of quicksilver and hog's lard, rubbed in every night lor four or six nights, will be sufficient to begin with. If the mouth is not affected the quantity may be gradually increased, till two or three drachms are rubbed in at each time; but if the first quantity has affected the mouth, we may be almost certain that the glands of the mouth are very susceptible of the mercurial stimulus; therefore it wiff be proper to wait two or three days till that effect begins to go off. When we begin the second time, the quantity may be gradually

^^hV' lGaSla -TUple,QVery time' tiJ1 tw° drachmsor more are rubbed in each night, which may be done without affecting the oteved!"7 C°nSlderab1^ a seco»d time, as has been alrfady

donl Wt6 Syr?.pt°™ graduj% disappear, there is no more to be security! 11S FaCtiCe f°r a f0rtniSht lon§er b7 way of This method, steadily pursued, will cure most recent cases of lues venerea but it is not sufficient if the disease has been mereh kept under by slight courses of mercury; a greater quantkv be comes necessary, from a kind of habit the consLtiorhas acoJired Vthe diV* ""h'6Z* l6SS SUSCCPtible 0f the »ial stimu1 u If the disease should return in the second order of parts !1

have been ulcers in the mouth 0 throat h, venereal ^P*"™ mercury being brought to ^Z^tlZ™^ 'i" ON THE CURE OF THE LUES VENEREA. 289 nated with it, and acting as a mercurial gargle, cured those parts locally, and that the constitution has remained still tainted, the mercurial action in it having been much inferior to what it was in the mouth. Perhaps something similar may take place in eruptions of the skin where the mercury passes off by sweat; for we know that sulphur will cure the itch by passing off in perspiration. If these are facts, then it may in some degree account for the local symptoms in the first order of parts being easier of cure than those in the second.* The manner of living under a mercurial course need not be altered from the common, because mercury has no action upon the disease which is more favoured by one way of life than another. Let me ask any one what effect eating a hearty dinner and drinking a bottle of wine can have over the action of mercury upon a venereal sore, either to make it affect any part sensibly, as falling upon the glands of the mouth, or prevent its effect upon the venereal irritation'? In short, I do not see why mercury should not cure the venereal disease under any mode whatever of regimen or diet.| I own, however, that I can conceive cold affecting the operations of mercury upon the venereal disease; it is possible that cold may be favourable to the venereal irritation, and therefore contrary to that produced by mercury ; and there is some show of reason tor supposing this, for I have before asserted that cold was an encourager of the venereal irritation ; and therefore keeping the ^patient warm may diminish the powers of the disease while under the cure. Mercury given internally is in many cases sufficient, although in general it is not so much to be depended on as the external application ; therefore I would not recommend it, or give it in cases where the disease has not been sufficiently cured by former courses of mercury.! It is the most convenient way of giving this medicine, for many will swallow a pill who do not choose to rub the body with the ointment; indeed there are many circumstances m life which make this mode of introducing it into the constitution the most convenient; but, on the other hand, there are; many constitutions that cannot bear mercury given internally. When these two circumstances meet in the same patient it is unfortunate Mercury taken internally often produces very disagreeable effects upon theTtomach and intestines, causing sickness in the one, and

^F££t£^^*" ^ internally, and it disagrees eitherwith the stomach or intestines, or both, even in the most simple Reparation, its effects, whatever they are, must be corrected * LAAoA • « After venereal blotches on the skin have been removed by mercury * Added . Alter ™"e;^rds which has led many to have recourse to mercury they sometimes recur a^^%W^esist some time, to see what becomes of again; bu* ^XTdisanneSa£in spontaneously; but as in some they may be t^Z^f^^Z% .-eh mercury must be given.»_ZW.

jp^hett^^^^ Home. 290 HUNTER ON THE VENEREAL DISEASE. or prevented, by joining with the mercury other medicines. If it affect the stomach only, the mercury may be joined with small quantities of the essential oils, as the essential oil of cloves, or camomile flowers, which will in many cases take off that effect. If it disagree both with the stomach and bowels, I believe it arises either from the mercury meeting with an acid in the stomach, by which part of it is dissolved, forming a salt, or from being given in the form of a salt, both of which will generally purge, and become the cause of their own expulsion. There are two ways of obviating these effects; the first is by preventing the salt from forming; the second, by mitigating its effects on the intestines if formed, by taking off their irritability. To prevent the salt from forming, the best way is to join the mercury with alkaline substances, either salts, or earths; and when given in a saline state it may be joined with opium, or some of the essential oils. To prevent the formation of the salt, take of the preparations of mercury, such as mercurius calcinatus, mercurius fuscus, or calomel, forming them into pills, with the addition of a small quantity of soft soap, or any of the alkaline salts; the alkaline salt also prevents the pill from drying; or instead of these a calcareous earth may be joined with the mercury, such as chalk or crabs'-eyes : upon this principle is the mercurius alkalizatus, which is crude mercury rubbed down with crabs'-eyes. But these substances add considerably to the bulk of the medicine, no less than twenty grains being necessary for a dose, which contains seven grains and a half ot crude mercury. The mercurius calcinatus, rubbed with a small portion of opium, makes an efficacious pill, and in general agrees well both with the stomach and bowels. Opium has long been joined with mercury to cure the venereal disease. By some as much has been attributed to the opium as the mercury; however opium should be given with care, for it is not every constitution Wlt.h,™ ^ agrees, often producing irritability, in some lassitude and debility, in other spasms.

Of a Sr TrT"7 H n0t ^ if" ^^ ,ab0VG man"er' but in the f°™ with „ tMrd f ^ r6,d t0 f°™' then il should be joined rX Th h n °P/Um' Snd a dr°P of the oil of cl°ves, or amovuXlh/^^l.^^^t^e with the stomach, and prevent its purging, or, if it is found still to disagree both with the stomach and bowels, compound it still further, by joining with the meTcurv the alkaline salts, the opium, and some essentia! oTl Y A grain of mercurius calcinatus made into a pill, with the addi tion of such medicines as the stomach or bowelsmay require mav

the evening, and one i "the „or„7„J 'nCreaSed '° tW° ^ins in

of mercurv to have the -fflL^^^ESSS ON THE CURE OF THE LUES VENEREA. 291 of the before-mentioned ; perhaps the proportion of their effects are about two or three to one. Why this should be the case is probably not easily accounted for, the quantity of mercury being very nearly the same in a given weight in both, for in eight grains of calomel there are seven grains of crude mercury. Three grains of these preparations appear only equal to one of the mercurius calcinatus. The crude mercury given in the same quantities with either of the former appears the least efficacious of all; for fifteen grains of crude mercury rubbed down with any mucilage, seems only equal to one or two of the mercurius calcinatus. The corrosive sublimate, which is a salt capable of stimulating violently, is generally given in solution in common water, brandy, or some of the simple waters, and has been used with the appearance of considerable success. It would appear that it removes ulcers in the mouth as soon, if not sooner, than any of the other preparations; but this I suspect arises from its application to these parts in its passage to the stomach, acting upon them locally as a gargle. However, from experience, it appears not to have sufficient powers over the venereal irritation; in recent cases only removing the visible local effects, without entirely destroying the venereal action: for many more have been found to relapse after having taken this preparation than from many of the others, which is owing to its passing very readily off by the skin. Besides, it disagrees much more with the stomach and intestines than any of the other preparations. , . , c A grain of this medicine, dissolved in about an ounce of some fluid, is generally the dose, and increased according as it agrees with the bowels, and according to its effects upon the mouth and

As corrosive sublimate contains an acid, and as you must be

* rThe nassao-e stands thus in every edition, and yet there mustbesome error, for the dose is larger than has ever been recommended by practitioners deserving ofCredit and could not be taken without danger The usual quantity is from a garter of a grain to half a grain in the course of the day, and even this is generally

divided '^0'AlJl^Z^orLue sublimate may be given with safety, if proper But larger quantities ot ™rrosi j ?ntroduced int0 lhe tenij V^^^^'^^V^ surfaces which immediately absorb it. without producing any irntat on on . u , lhe form of a in, and by And this object is besynm^edsobythatmit may mix with the food, and its acrid giving it at the ^jteoT It will be found that corrosive sublimate ^TaKS in th s way, in e dose of one third of a grain, three times in the may be given in this way, > inconvenience, or more risk of derangetl^l^lSZ'tSoviet tha" is incurred from the ordinary doses, given

without these Prei:autl0"s- course of corrosive sublimate gives the patient little An opinion preva, that a ™urs£s°errvation ]ies chiefly to the smaller doses security against a elapse, in introduction of a sufficient quantity of the remedy, wh ch^aree'y rn prolonged. If it be given in of **™™l'.w^£Z™j£r£*ldIA* course can be continued for the the dose which is mentioned ab v ^ ^ ^ rmtClu^Sther "Ssesare more frequent than after the exhibition of other preparations of mercury.] 292 HUNTER ON THE VENEREAL DISEASE. guided by the effects of the acid on the bowels, the quantity of mercury you can give in this form is necessarily smaller than in the other preparations. Ward's drop, containing less acid, can be given in larger quantity, and is more efficacious on that account. Perhaps any of these preparations united with a scruple of gum guaiacum may have more effect than when given alone, since guaiacum is found to have considerable effects on the venereal disease.* This practice, continued for two months, will in general cure a common lues venerea; but here it is not meant that any time should be specified. After all the symptoms of the disease have disappeared, this course should be continued at least a fortnight longer; but if the symptoms disappear very suddenly, as they often do, perhaps within eight or ten days, probably from the medicine going off by those surfaces where the disease appears, the medicine should be continued three weeks, or perhaps a month, longer, and the dose increased. In such cases the visible local effects appear to be cured while a venereal disposition remains in the parts. Various are the preparations of mercury recommended for internal use, while practitioners have generally been satisfied with but one for external application. Every practitioner finds some one of the preparations answering better to appearance in some one case than another, which casts the balance in favour of that medicine in his mind ; or others, finding the bad effects of a particular preparation at one time, have generally condemned that preparation; not to mention that deceit is often practised in the cure of this disease. One would naturally suppose that the simplest preparation is the best, that which is easiest dissolved in the animal juices, does least mischief to the stomach or general health, and is least disturbed or hindered in its operations ; for we can hardly suppose that any substance joined with mercury, which alters either its chemical or mechanical properties out of the body, can add to its power in the body, except a substance which had a similar power when acting alone. The preference generally given to the ointment shows this; and if we could find a preparation still more simple than the ointment, that preparation should be used in preference to the crude mercury.

§ 6. Of the Cure of the Disease in the second or third Stage.

JZ lt moZe*dv™ced stages of the disease the mercurial course S f' The greatest C>liantity of that medicine that the patient can bear at a time is to be thrown in, and continued with steadiness till there is great reason to L.Z^l* S, ?ntinue.d decrown it ™,;n „«♦ V g •. ,rea.son t0 suppose the disease is destroyed. It will not be possible in such cases to prevent the mouth from being considerably affected, the quantity of mercurv

rngCesucahya win inmos? ci* ^ ,°f **? ^ of ^ disease be" ing sucn as win in most cases produce that effect. * See post. ON THE CURE OF THE LUES VENEREA. 293 Before the disease has advanced so far the patient most probably has taken mercury, and it is proper to inquire how he has been affected by it, and what quantity he can bear, which will in some degree direct us in the quantity now to be begun with. If the patient has not taken mercury for a considerable time, and is easily affected by it, which is the case that admits of the least quantity, it will be necessary to begin cautiously, regulating the quantity according to circumstances ; but if the person has taken mercury lately, although easily affected by it, more freedom may be used on returning to it, because it will have less power on his mouth, as also on the disease. Again, if the person has been taking mercury very lately, and is with difficulty affected by it, which is the case that admits of the greatest quantity, then it may be administered freely so as to affect the constitution in the proper time. If the mercury is brought to the mouth in six or eight days, and a considerable soreness is produced in twelve, it will in general be a good beginning. In such cases the constitution is, if possible, to be surprised by the medicine, so as to produce its greatest effects, but with such caution as to be able to keep up these effects by quantity. Mercurial friction will answer better than mercury given internally ; for in this way we are surer of throwing in a larger quantity in a given time than could be taken internally without hurting the q f a tyi 3 f* h The quantity of mercury applied in this way should be, under certain circumstances, in proportion to the surface on which it is applied, and the surface should be completely covered with the ofntment; for half an ounce of mercurial ointment, rubbed in upon a Sven surface, will have nearly the same effect as one ounce rubbed In on the same surface; therefore one ounce to have double the effec" should have double the surface. The quantity of ointmLt must therefore be adapted to the quantity of surface, for on a cTrtain extent of surface no more than a determined quantity of oL mentcan be applied so as to be absorbed, and applying a greaTei quantity would be useless ; and if the quantity of surface « greatei qudii y tion of ointment cannot be diffused so as to greater, the same• PO"1^ E surface which is used may employ fully all the ah,soi benfcs y ^ ^ ghould

Lt""If we ^ ^UrLe the effects of the mercury to the

quantity. alwavs the practice to rub the mer- It has most probably^been always ,h^p ^ ^ cury wellm, a it is termed D P^ ^ & rf from an idea of the .^ce D faction of vessels ; and it is pro- SCattw"fetimirtttselS produeing absorption may be rather disturbed than^cited by frie.mn ^ ^

How 1°"3 *e.c°uhV0Sue;hSt proper to eontii.ee it till the local antained ; H may ^W^ . but i suspect that this ,s hardly 294 HUNTER ON THE VENEREAL DISEASE. complaints, or tumefaction, &c, generally require a longer time to be removed than the venereal action; and local applications must be of service, especially if such tumefactions are obstinate. The manner of living under such a severe course, which is in every respect weakening, is to be particularly attended to. The patient must be supported; and the local effects of the medicine, in the mouth, preventing his taking many kinds of nourishment, especially such as are of a solid form, fluids must form his only nourishment, and these should be such as will become solid after they are swallowed : milk is of this kind. An egg beat up with a little sugar, and a little wine, sago, salep, &c. form a proper diet. In many cases wine and bark must be given through the whole course. Sugar is perhaps one of the best restoratives of any kind we are acquainted with, when a constitution has been very much debilitated by long fasting, from whatever cause, whether from the want of food when in health, or in the time of disease, or where the food has not been allowed to answer the constitutional waste, as in a course of mercury ; and when the disease or course of mercury is gone, then sugar will restore such constitution, probably better than anything else. Although it is not a common opinion, and therefore not a common practice, to give sugar entirely with this view, yet there are sufficient proofs of its nutritive quality over almost every other substance. It is a well known fact that all the negroes in the sugar islands become extremely lusty and fat in the sugar-cane season; and they hardly live upon anything else. The horses and cattle that are allowed to feed upon them all become fat; the hair of the horse becomes fine. Birds which feed upon fruit never eat it till it becomes very ripe, when it has formed the greatest quantity of sugar, and even then only such as furnish the largest quantity of sugar. Insects do the same; but we cannot have a stronger instance of this fact than in the bee. Honey is composed of su»ar with some other juices of plants, with a little essential oil; but sugar is the principal ingredient. When we consider that a swarm of bees will live a whole winter on a few pounds of honey, keep up a constant heat about ninety-five or ninety-six degrees," and the actions of the animal economy equal to that heat, we must allow that

substance PS m°re ^ nourishment than ™Y other known

narTnfThI00Aat WhG;Y iS extremeIy fattening, which is the watery

entirely escaped the ^V^^^JV^ h™ T sennngthe negroes in ,he wit l^^Jg I *fc£ ON THE CURE OF THE LUES VENEREA. 295 season, has been induced to give it in very large quantities to many of his patients, and with very good effects. Honey is perhaps as good a mode of taking this substance as any. Sweetening everything that is either eat or drunk, whether by sugar in honey, or sugar alone, is probably immaterial. Yet it is probable that the other ingredients in honey may add to its nutritive quality.

If the local effects have gone no further than inflammation and swelling, either of the soft or hard parts, most probably no local treatment will be necessary, for the treatment of the constitution will in general remove them entirely. It sometimes, however, happens that the local complaints will not give way, but the parts remain swelled in an indolent and inactive state, even after there is every reason for supposing the constitution is perfectly cured. In such cases the constitutional treatment is to be assisted by local applications of mercury to the part, either in the form of a plaster or ointment. The latter is by much the best mode. If these are not sufficient, as often happens, we must endeavour to destroy this disposition by producing an inflammation of another kind. I have seen a venereal node, which gave excruciating pain, cured by an incision only being made down to the bone the whole length of the node; the pain has ceased, the swelling has decreased, and the sore healed up kindly, without the assistance of a grain of mercury. Blisters have been applied to nodes with success; they have removed the pains and diminished the swellings ; so far furnishing a proof that local treatment may assist mercury in many cases. This treatment has not only been used to assist mercury in those cases where the medicine did not appear to be equal to the disease, but it has been used at the commencement of the cure, and even before mercury had been applied; but it was still thought necessary to go through the same mercurial course as if nothing had been done to the local complaints. .... It may be asked, What advantage arises from the incision or application of the blister ? The advantage is immediate relief from violent pains ; and as there are two powers acting, it is natural to minnose the cure will be more speedy. After alf the above-mentioned trials, it may happen that the local effects shall still remain, forming as it were a new disease, which mercury mat increase, and therefore other methods of cure may be tried, as will be described hereafter.

§ 8. Of Abscesses—Exfoliation.

xxru on nWess forms in a node in the periosteum the bones When a ^mcm torms j^ Gfeat

tion^uuW3t; X>«n. for suppurations in them are not like 296 HUNTER ON THE VENEREAL DISEASE. suppurations in common abscesses; they are seldom produced from the true suppurative inflammation, and therefore are slow in their progress, rarely producing true matter, but a mucus, something resembling slime, which lies flat upon the bone. This circumstance makes it difficult to determine when suppuration has taken place, and in many cases to detect matter, even where it is formed. Another circumstance, which renders the presence of matter in such cases doubtful, is, that the progress of the disease is generally checked very early by the use of mercury. This matter is often reabsorbed during a mercurial course, and it is proper, particularly in an early state of the complaint, to give it this chance ; but if the absorption does not take place, and the complaint is in an advanced state, it must be opened. The surgical treatment of the parts under such circumstances is the same as in other diseases of these parts; opening with great freedom is absolutely necessary ; for the more parts are exposed, the more inclinable they are in general to heal, and still more so here ; for violence assists in destroying the venerea] disposition. No skin covering a bone should be removed from an abscess, especially in the lower extremities. If the abscess is opened freely, and an exfoliation takes place, which is generally the case, it is to be treated as1 any other exfoliation. Exfoliations succeed much better here than in many other cases, because the disease from which they proceed can generally be corrected, which is not the case in many diseases of bones where exfoliation takes place. Cases, however, sometimes occur in which, after the venereal disposition has been corrected, another disease takes place in the bone, the nature of which will be explained when we shall consider the effects remaining after the disease is cured, and the diseases sometimes produced by the cure.

§ 9. Of Nodes on Tendons, Ligaments, and Fascice.

The observations made on the nodes of the periosteum and bones are applicable to swellings and suppurations of the ligaments and fascias ; but it is still more difficult to ascertain the presence of matter in them than in the former. When a thickening only of the ligaments or fascia? is the consequence of the disease, it is very obstinate, as in many cases the diseased part may be cleared of all venereal taint and still the swellings remain. Blisters may often be applied here with success ; but if they fail, then it will be absolutely necessary to make an incision into the part, to excite a more vigorous action ; for although the complaint has nothing venereal in it, nor is any contamination to be feared from it in future, yet as it leaves often very obstinate and disagreeable swellings, which neither give way to medicine nor time, it is proper to use every means for their removal. ON THE CURE OF THE LUES VENEREA. 297 § 10. Of Correcting some of the Effects of Mercury,

Formerly, when the management of mercury was not so well understood, nor its effects in this disease so well known as they are at present, it was generally supposed to act by evacuation from the salivary glands, and was therefore always given till that evacuation took place; and, as its effects in the cure were imagined to be in proportion to the quantity of this evacuation, it was pushed as far as possible without endangering suffocation. From this treatment it often happened in those constitutions which were very susceptible of the mercurial irritation, and in which the medicine produced much more violent effects on some particular secretions than could be wished, that recourse was obliged to be had to medicines correcting the effects of mercury, as these effects were often a hindrance to its being given in sufficient quantities for the cure of the disease. I mentioned, when treating of the effects of mercury, that the sensible increase of the secretions produced by it were in the following order: first of saliva, then sweat, then urine, and often of the mucus of the intestines, producing purging; I also observed, that when any of those secretions became too violent, the hand ot the surgeon was tied up till they were moderated. Attempts have been made to lessen those effects in two ways, either by the destruction of its power on the body in general, or by its removal, but neither of these means has succeeded. It never has once been thought necessary to attempt to lessen its powers on the organs ot secretion, so as still to retain the same quantity in the constitution, or even to throw in more, which, if it could be effected, would be sometimes of great service; but as we are not yet acquainted with powers sufficient for these purposes, we are obliged to observe great caution in our mode of giving the medicine. I have endeavoured to show that this medicine need not be given with a view to procure those evacuations, and that it may be given in any quantity without increasing either of those secretions in any evident degree; however, after every precaution we may still be deceived and the medicine will every now and then produce areaZr effects than were intended. It is very necessary therefore fo seek fo-a preventive of the effects of mercury, when likely to oe too violent for to remedy those effects when they have already

taken pl»ce- . when mercury produced violent effects The; common practice, wn ^e effects ; but this was upon the inte**a%™ ££ the mercury in the constitution, but not done with «* ™^*J^£ suffering by the action of the medito relieve the bowels ™r practice would be to stop its progress E; al ire'iy othPer°Poutlel that more mercury may be retained

in the constitution. secreti0ns arise from the constitution's 298 HUNTER ON THE VENEREAL DISEASE. for they do not arise from an universal disposition becoming a local or critical one; and therefore if such an action be checked or stopped in one place, it must necessarily fall upon some other; but it is from the part being more susceptible of this irritation than any other, and the quantity now in the constitution being equal to the susceptibility of the part: and, therefore, though its effects are stopped here, it does not break out anywhere else, every other part being capable of supporting this quantity, and of remaining unaffected till more is thrown in. When the mercury attacked the salivary glands, it increased that secretion so much as in some cases to oblige practitioners to administer such medicines as were thought likely to remove this new complaint. This susceptibility of the glands of the mouth, and the mouth in general, to be easily put into action by this medicine, was generally supposed to arise from a scorbutic constitution, to which most complaints of the mouth are attributed. I am of opinion that scrofulous people, and those of a lax and delicate habit, arc more subject to have it fall on the mouth than those of a contrary temperament. - Purges were given upon a supposition that mercury could be carried off by the evacuation produced by them, and they were repeated according to the violence of the effects of the medicine and the strength of the patient; but I can hardly say that I ever have seen the effects of mercury upon the mouth lessened bv purging, whether it arose spontaneously, was produced by purging medicines, or even when arising from the mercury itself. As this method was not found sufficient for the removal of the complaint, other medicines were tried; sulphur was supposed to be a specific for the removal of the effect of mercury. Whether this idea arose „Ta P? w °r reasoning is not material,* but I think I have seen good effects from it in some cases. If we can suppose purging of

eYerr^tTe^loti:^ "^ 7°U,d «-wer K.t, a? it^uld exert its effects both as a purge and a specific. fculphur certainly enters the circulation as sulphur, because our sweat and urine smell of it; if it does not combine with tl^^mercury and destroy its properties as mercury, it is possible ao-reeTblv to the opinion of those who first though of" J^n* it Jwh 7i7 intention, that it may so combine as to.form, /R?W ? * ithlS something similar, for we know"hat the £tW P * T^' °T formed, cfoe. not in genera] salivate It if no 1 le tTrhi, Th^ may act as a contrary stimulus to merrnR? I' ' thatsu,Phur effects of it in the constitution SulXr ha'e/enn"^^"^^16

^^■-^ feulphur, united with any of the metal* nml, ui j in the juices, or at least their effects in thp^ Pw?y deStr°yS their solubility either as sulphur or mercury. Crode n?u?mTv L°-^ "°ne °f the cin"^ars act has no effect. Arsenic, „£. Joi^ S^u^ »„ 35^tffi.? ON THE CURE OF THE LUES VENEREA. 299 cases, we must either allow that they enter the circulation, or that their whole effects are on the stomach and intestines, with which the rest of the body sympathizes. The good effects from sulphur in lessening or altering the immediate effects of mercury, can only take place when that medicine is really in the constitution; therefore a distinction is to be made between such as arise immediately from mercury, and one continued from habit, after the mercury has been evacuated from the constitution; a case that sometimes happens, and which will be taken notice of in its proper place.* The taste in the mouth, from the use of mercury, has been known to go off, and not be perceived for a fortnight, and the same taste has recurred: this I am informed has happened twice to one gentleman, from the first quantity of mercury taken, lo account for this is not easy; in whatever way it happens, it is a curious

aWhen the mercury has fallen upon the mouth and throat, washin* those parts with opium has often good effects ; for opium takes^ off irritability, and of course the soreness, which is one means oi lessening the'secretion. A drachm of tinctura thebaica to an ounce of water makes a good wash or gargle.f When the mercury falls upon the skin, it is neither so disagreeable nor so dangerous as when it falls upon the mouth; however, it may often happen that it will be proper to check such a discharge, both upon account of its being troublesome, and of its lessening the effects of the medicine in the constitution by carrying it oft. lhe bark is, perhaps, one of the best correctors of this increased secre-

10When the medicine attacks the kidneys and increases the secretion of those glands, it is not so troublesome as when it produces sweating, though it is possible that it may carry off the mercury too soon; but as we have but few medicines that can tessen that secretion, in most cases it must be allowed to go on. The bark may in such cases be given with advantage. When the mercury falls upon the bowels, it proves often more dangerous and troublesome than in any of the former cases, especially the two last; but it is,perhaps, most in our power to prevent or ml hate Opium should be given in such quantities as to overcome the complaint, and I believe will seldom fail of removing all the symptoms-!

* [Nitric acid has far more power than any other medicine in checking and curing soreness of the f^™ «J Efrom inalogy. Finding that opium quieted J^y^\°^Z^l^eZin consequence of mercury,I tried it by ^"argtto the'mS, abound good effects from it, but not equal to those which-it produced in **%*$. occurrence of disorder of the bowels from mL[u°rylU bu7 wh^dyKn'rical symptoms are actually present, it will seldom rTmoveVhem unless it be preceded by a purgative.] 300 HUNTER ON THE VENEREAL DISEASE. §11. Of the Form of the different Preparations of Mercury when in the Circulation.

It would appear from reason, and many circumstances, that mercury must be in a state of solution in the juices of the body before it can act upon the venereal disease, and indeed before it can act upon any other disease. That mercury is in a state of solution in our juices, and not in the state of any preparation of mercury that we know of, is very probable from the following facts. First, crude mercury, every salt of mercury, and calx of mercury, is soluble in the spittle, when taken into the mouth, by which means it is rendered sensible to the taste; from thence it must appear that it is capable of solution in some of our juices. Secondly, crude mercury, when divided into small parts by gum arabic, &c, so as to be easier of solution when taken into the stomach, generally purges; but crude mercury taken without such division has no such powers, not being so readily dissolved in the juices of the stomach. The simple calx of mercury has the same effects, purging, and much more violently, from being, I suppose, readier of solution in the animal juices; for if it only purged from its union with the acid which happened to be in the stomach, it most probably would not purge more than crude mercury; although it is very probable that the calx is easier of solution in a weak acid than even the crude mercury. Thirdly, every preparation of mercury producing the same effect in the mouth, and also having one and the same effect in the constitution, shows that they must all undergo a change by which they are reduced to one particular form. We cannot say what that form is, whether it is the calx, the metal, or any other that we are acquainted with; but it is probable that it is not any of them, but a new solution in the animal juices peculiar to the animal itself. lhis is rendered still more probable by this circumstance, that every preparation of mercury put into the mouth undergoes the same change, and the spittle has the same taste from every one of them. If every different preparation of mercury had the same properties in the constitution that it possesses out of it, which we must suppose ,f it enters and continues in the same form, in that case the venereal poison must be eradicated in as many different ways as here are preparations. Crude mercury would act

Soeo1an;h:I,y',by ^T^r^ Wei^ht and -omentum of th blood; the calx would act like brickdust, or any other powder that is heavy; the red precipitate would stimulate by chemica properties in one way, while the corrosive sublimate would actin another, and the mercurius flavus in a third ; this last would moS

another Jofcof*.^ inp; ON THE CURE OF THE LUES VENEREA. 301 to the specific nature of the preparation. The red precipitate is a preparation of this kind, and acts in both these ways: it is either a stimulant or an escharotic. To ascertain whether this opinion of mercury being in solution in our juices was just, I made the following experiments upon myself. I put some crude mercury into my mouth, as a standard, and let it stay there, working it about, so as to render it easier of solution, till I tasted it sensibly; I then put into my mouth the mercurius calcinatus, and let it remain till I perceived the taste of it, which was exactly the same; but I observed that it was easier of solution than the crude mercury. I tried calomel in the same way, and also corrosive sublimate, after being diluted with the water, and the taste was still the same. It was some time before I perceived the taste of the crude mercury in my mouth. I tasted the calx and calomel much sooner. The corrosive sublimate had at first a mixed taste, but when the acid was diluted it had exactly the same taste with the former: all these different preparations producing the same sensation or taste in the mouth. From the effects of these experiments it would appear that the mercury in every one of them was dissolved in the spittle, and reduced to the same preparation or solution. To try whether mercury in the constitution would produce the same taste in the mouth, 1 rubbed in mercurial ointment upon my thighs till my mouth was affected, and I could plainly taste the mercury; and, as far as I could rely upon my memory, the taste was exactly the same as in the former experiments. I allowed some time for my mouth to get perfectly well and free from the taste ; I then took calomel in pills till it was affected again in the same way. I afterwards took mercurius calcinatus, and also corrosive sublimate. All these experiments were attended with the same result; the mercury in every form producing the same taste, which was also exactly the same as when the several preparations were put into the mouth. P From the above experiments it must appear, that when mercury nrnHneps evacuation by the mouth it certainly goes oft in that discharge anTfrom thence we may reasonably conclude that when Scionsare■ F^^^ J^^^'i£ Z:TTgSsSWrracua^ions, which become outlets to

""Framthe above experiments it appears to be immaterial what i rorai the a rove■ j cure of th]s dlsease> provlded

ft^rf easy s0olu"Sn inou? juices, the preparations easiest of solution being always the best.

c 12 of the Operation of Mercury on the Poison. mflvhe SUpposed to act in three different ways in curing theTenS ».Tirst, it may unite with the poison chemically, 302 HUNTER ON THE VENEREAL DISEASE. and decompose it, by which means its powers of irritation may be destroyed; secondly, it may carry it out of the constitution by evacuation ; or, thirdly, it may produce an irritation in the constitution which counteracts the venereal and entirely destroys it. It has been supposed that mercury acts simply by its weight in the circulating fluids, but of this we can form no adequate idea; and if it were so, other substances should act on this disease in proportion to their weight, and of course many of them should cure it. . But from experience we find that such bodies as have considerable weight, as most of the metals, have no effect on this disease. We have no proof of mercury acting by a decomposition of the poison from any of the concomitant circumstances. Mercury certainly does not cure the venereal disease by uniting with the poison and producing an evacuation. For in those cases where mercury is given in such a way as to produce considerable evacuations, or in those constitutions where evacuations are easily excited by mercury, its effects upon the diseased action are the least; and the same evacuations produced by any other means have not the least effect on the disease. Whether the mercury be supposed to carry off the circulating poison or to decompose it, in neither way could it produce, when locally applied, any effect on a venereal inflammation or sore arising from the constitution; for as long as any of the poison existed in the circulation, none of them could be healed by local applications, the circulation constantly carrying the poison to them; but we find the contrary of this to be true, for a venereal sore arising from the constitution may be cured locally. The last or third of our modes of action of mercury seems to me the most probable, and for many reasons. First, because the disease can in many cases be cured by raising a violent stimulus of another kind ; and perhaps if we could raise such a constitutional irritation without danger, as we often can in local cases, we might cure the venereal disease in the same manner, and in one quarter of the usual time. Secondly, we find that mercury acts as an universal stimulus, causing great irritability in the constitution, making the heart beat faster, and rendering the arteries more rigid, so as to produce a hard pulse, as has been already observed. It may further be said to produce a disease, or a peculiar or unnatural mode of action, in a certain degree. The following case will illustrate this. A gentleman had electricity recommended to him for some complaint he had. The electricity was applied, but without any visible effect. Besides the complaint for which he used electricity, he had a venereal one, for which he was first put under a course of mercury, and while under it the electricity was applied for the former complaint; but he had become so irritable that he could not bear the shocks of one half their former strength. But the most curious part of the case was that the shocks had a much greater effect on the disease than what they had before when twice as strong, and he now got cured. This gave the surgeon a hint; and ON THE CURE OF THE LUES VENEREA. 303 having another occasion to use electricity, also without effect, he put the patient under a gentle course of mercury, and then found the same effects from the electricity as in the former case, and the patient also got well. The powers of mercury upon the constitution appear to be as the quantity of mercury and the susceptibility of the constitution to be affected with it, without any relation to the disease itself; and we find that the power of mercury upon the disease is nearly in the same proportion. This fact gives us an idea of the irritation of mercury upon the constitution, and consequently an idea of administering it, and of the cure of any disease for which it is a remedy. As we find that a given quantity of mercury produces double effects in some constitutions to what it does in others; also, that in those cases it produces its effects upon the disease, we are led to believe that it is this effect upon the constitution which cures the disease ; and therefore if it did not produce this effect it would also not have performed a cure. I have already observed that the cure does not go on exactly in proportion to the visible effects upon the constitution, except quantity in the medicine is joined with it, which, if true, would incline us to believe that there was something more than simply a constitutional stimulus, which most probably is a peculiar specific effect which is not regulated entirely by its visible effects, either constitutional or local, although they appear to have some connexion. This fact being known, obliges us to be more liberal in giving mercury in those constitutions where it makes but little impression, than in those which it easily irritates; although in these last we must not be entirely regulated by its local effects, nor depend upon a commonly sufficient quantity, but be ruled by the sensibility of the constitution and quantity joined; for in those where the constitution appears to be very susceptible of the mercurial irritation, where small quantities produce considerable local effects, it is still necessary to have quantity, although it is not so necessary to take the quantity in general that is supposed to be sufficient. We must be guided by the three following circumstances, the disappearance of the disease, the quantity of irritation produced, and the quantity of the medicine taken.

& 13. Of Gum Guaiacum and Radix Sarsaparillce in the Venereal Disease.

I have hitherto only recommended mercury in the cure of the venereal disease, and indeed it is the only medicine to be depended upon However, as both the guaiacum and sarsaparilla have been recommended as powerful remedies in this complaint, I took a favourable opportunity of trying their comparative powers in the venereal disease upon the same person. 304 HUNTER ON THE VENEREAL DISEASE. The guaiacum* I found had considerable specific power over the disease, consequently it may be of service in slight cases where it may be inconvenient or improper to give mercury on account of some other disease. These cases, however, I have not yet ascertained : or it may be given in those cases where it is apprehended that the quantity of mercury necessary to subdue the disease would be too much for the constitution to bear, cases which sometimes occur. The sarsaparilla appeared to have no effect at all. I shall relate exactly the case in which their comparative powers were tried. A man came into St. George's Hospital with venereal sores over almost his whole body: there were many excrescent sores in the arm-pits, some of which were about the size of a halfpenny ; there were the same appearances about the anus, between the buttocks, along the perinaeum, between the scrotum and thigh, where those parts come in contact with one another. Those upon the skin in general had the common appearance. I ordered a poultice of the gum guaiacum to be applied to the sores in the right arm-pit; also a poultice of a strong decoction of sarsaparilla and oatmeal, mixed, to be applied to the left arm-pit. These poultices were changed every day for a fortnight; the excrescent sores in the right arm-pit were entirely healed, and become even with the skin, and covered with a natural skin, although somewhat discoloured ; the sores in the left arm-pit, which were poulticed with sarsaparilla, were rather worse than when the poultice was first applied, as indeed were all the sores, except those in the right arm-pit. I then ordered the poultice of guaiacum to be applied to the left arm-pit, which was done, and the sores there also got well in a fortnight. I was now perfectly convinced that the gum guaiacum had cured these eruptions locally. I next wished to see what effect the gum guaiacum would have upon the remaining sores when given internally, that is, those about the anus, scrotum, and on the skin in general. The patient began with half a drachm three times every day, which purged him ; but this was prevented by joining it with opium. In about four weeks all the eruptions were cured, and he was allowed to stay in the hospital some time longer, to see if he would continue well; but about a fortnight after he began to break out 'anew, and in a very short time was almost as bad as ever. I began a second time the gum guaiacum internally, but it had lost all its powers, or rather the constitution was no longer affected by it. He was put under a course of mercury, and cured.f * The lignum guaiaci was imported by the Spaniards from Hispaniola, as a cure for the venereal disease, in the year 1517, having been given to one of them by a native. f [For a detailed examination into the use of these and other remedies in the venereal disease, the reader is referred to » Observations on the effects of various articles of the Materia Medica in the cure of Lues Venerea," by John Pearson, awork which contains the result of a long and extensive experience, chiefly Slxcelle'nt ^!K^ P"tlCT,» SUb*Ct' *nd ta ta '^ «*« EFFECTS, ETC., OF THE LUES VENEREA. 305 CHAPTER IV.

dF THE EFFECTS REMAINING AFTER THE DISEASE IS CURED, AND OF THE DISEASES SOMETIMES PRODUCED BY THE CURE.

In treating of the local effects of the venereal disease, the gonorrhoea, and chancre, as also the bubo, I observed, that after the virus was destroyed there remained in many cases some of the same symptoms, and particularly after the gonorrhoea. It was also observed, that though all the symptoms were entirely cured, yet they were liable to break out again. A gleet will appear, sometimes attended with pain, so as to resemble a gonorrhoea; after chancres there will be sores resembling them; and buboes after the virus is gone, will not heal, but spread. In the lues venerea the same thing often happens, especially if the inflammation and suppuration have been violent in the parts. These cases puzzle considerably; for it is difficult to say when the venereal virus is absolutely gone. In such doubtful cases the treatment to be followed becomes more undetermined. Such complaints are more common in the tonsils than in any other part, for we often find that while a mercurial course is going on, and the ulcer on the tonsils healing, or even healed, they shall swell, become excoriated, and the excoriations shall sometimes spread over the whole palatum molle, which renders the nature ot the disease doubtful. I believe these excoriations,, as well as such other appearances of disease as come on during the use ol mercury, are seldom or never venereal. In all such cases I would recommend not to continue the mercury longer than what appears sufficient for overcoming the original venereal complaints, not considering those changes in the case as venereal, lhe bark is often'of service here, and may be given either with mercury, or after the mercurial course is over. It often happens that venereal abscesses will not heal up, although they have gone a certain length towards it, for while the venerea action remained in the part, the mercury disposed that part to heal; bu undeTthat course* the constitution and part had acquired another disposition, proceeding from a venereal and mercunalirntatkm affS particular habit of body or part, at the time wmch new dfsposition differs from the venereal, mercurialand natural bein- a fourth disposition arising out of all the three. I suspect however, that it depends chiefly on the constitution, because 'k was owing to the other two, we should always have the same it it/was °™"b R this opinion more probable is, that it aT"*} irlni people? atleast it is not cured in all by the same differs ^^^^^ being predisposed, the other two become KneoUtocauses of action! P As soon as the venereal irritation 306 HUNTER ON THE VENEREAL DISEASE. is destroyed by the mercury, or becomes weaker than the other two, then the effects of the others take place. While the venereal action prevails the mercury is of service, and the sore continues healing; but when it is lessened to a certain degree, or destroyed, the mercury not only loses its powers, but becomes a poison to the new disposition that is formed; for if mercury is continued, the sore spreads ; it should therefore be immediately left off. Sonne of the sores formed in this way not only resist all means of cure, but often inflame, ulcerate, and form hard callous bases, so as to put on the appearance of a cancer, and are often supposed really to be so. We find also that new diseases arise from the mercury alone. The tonsils shall swell where no venereal disease has been before; the periosteum shall thicken, and also probably the bones, and the parts over them shall become cedematous and sore to the touch; but as these complaints arise while under a mercurial course, they are not to be reckoned venereal, but a new disease, although they are too often supposed to be venereal, and on that account the mercury is pushed as far as possible. In such cases, if the complaints for which the mercury was given are nearly cured, and the medicine has been continued a sufficient time after to complete the cure of those complaints, then of course it should be left off; and if there be any doubt, it should be left off rather sooner than if no such complaint had taken place, because it is probably producing a worse disease than the venereal; and if, after the cure of these complaints from the mercury, the venereal disease begins again to come into action, mercury must be given a second time; and now the constitution will be better able to bear it, especially if attention has been paid to the restoring the strength of it. Those diseases of the tonsils and periosteum I suspect to be of scrofulous origin. Besides local complaints, arising from the combined action of the mercury, the disease, and the constitution, there is sometimes a constitutional effect, which is a weakness or debility, a languor, want of appetite, frequent sweats threatening hectic; but these happen mostly in those constitutions with which mercury disagrees. These complaints, local as well as constitutional, arise in some measure from weakness. They are difficult of cure, whether arising from a venereal chancre, bubo, or the lues venerea. Strengthening medicines are of most service: the bark is of great use, though in general not sufficient, as it can only more or less remove the weakness, the specific qualities still remaining. What these are is, I believe, not yet known; but I suspect that many partake of the scrofula, and this opinion is strengthened by their frequently giving way to sea-bathing.*

* In a case of an ulcerated rib from a venereal cause, and five nodes on the shin-bone, of twelve months' standing, a deep salivation of six months was undergone afier fruitless attempts by gentle friction. None of the sores were healed by the mercury, and the patient was ordered to bathe in ihe sea, and take he the last o^al?6 " ^ ^ ^ "" hea,ed ^ ^ kin< bu< *• - 3e EFFECTS, ETC., OF THE LUES VENEREA. 307 § 1. General Observations on the Medicines usually given for the Cure.

A decoction of the woods, among which are commonly included guaiacum and sarsaparilla, is one of the first medicines in the cure, and many of the cases yield to it, which gives them the credit of curing the venereal disease, while such diseases were supposed to be venereal. The sarsaparilla was often given alone, and was found to produce nearly the same effect. The good effects of it in one case gave it some reputation.* A diet-drink discovered at Lisbon was also of considerable service, and as it cured cases similar to those cured by the sarsaparilla, it was imagined that the diet-drink consisted principally of a decoction of this root. This was still on the supposition that all those cases were venereal; but it was observed at last that those medicines did not cure this disease till mercury had been given, and in a tolerably large quantity. This was sufficient to lead some thinking minds to doubt whether they were venereal or not; and their being cured by different medicines ought to produce a conviction of their being different from the venereal disease, and that they are themselves of different kinds. The mezereon has also been found to be of service in some symptoms of the lues venerea, such as nodes of the bones; but thenbeing venereal was taken for granted. The mezereon is seldom given in venereal ulcers in the throat, or blotches on the skin, which, of all the venereal symptoms, are the most certain, and the most easy of cure; yet it was conceived that it removed such symptoms as are the most difficult of cure; but all those cases in which the mezereon has been given with success plainly appear not to have been venereal. When the hemlock came into fashion in this country it was o-iven in almost every disease, and of course was tried in some of Those complaints consequent to the venereal disease, and some ot these it was found to cure, so that it now stands upon the list ot remedies. Velno's vegetable syrup has had similar effects in some of these cases, and opium appears also to have many advocates. Opium, like the sarsaparilla and mezereon, was supposed by its first introducers to cure the lues venerea.t but, like the sarsaparilla, it appears to have no effect till mercury has done its best or its worsft It has certainly considerable effects in many diseases, both in such as are consequent to the venereal disease, and others

&t^/Cnfng "urite medicine of mine, not only as relievng pain? for that is its common effect, but as a medicine capable of altering diseased actions, and producing healthy ones. In all

* See London Medical Essays, a case published by Mr. Fordyce, now Sir

^^^edtTbommun-jcations vol^^ page 307. \ See a pamphlet published by Mr. Urant. 308 HUNTER ON THE VENEREAL DISEASE. sores attended with irritability, a decoction of poppy heads, made into a poultice, is an excellent application. Bleeding sores that do not arise from weakness, but from irritability, have the bleeding stopped immediately by this application. Mr. Pott is, I believe, the first who showed the world its use in mortifications. My first mode of applying it for the cure of diseases was locally, in which I found it had most salutary effects in some cases, and it was ordered afterwards internally upon the same principle ; and it was also found to have salutary effects in this mode. In two cases that had been long suspected to be venerea], its effects were very remarkable, and, by its having cured them, it confirmed me in my opinion that they were not. But when I was informed, that they cured the venereal disease in the army in America by opium, I then began to question myself, whether I had formed a right judgment of the nature of those two cases which were cured by opium. To ascertain whether opium would cure the lues venerea or not, I made the following trial at St. George's Hospital. A woman was taken into the hospital with blotches on her skin, which had arrived to the state of scabs, and with well-marked venereal ulcers on both tonsils. A grain of opium was ordered to be taken the first night, two the second, and so on, increasing a grain every night, unless something should arise to forbid it. This was closely followed till the nineteenth night, when she was ordered a dose of physic, as she had become costive, and the opium was omitted. On the 20th she began again, and continued increasing the dose, as before, till it amounted to thirty grains, no alteration being produced in the sores, except what arose from the loss of time, whereby they were rather worse. I concluded, that if she had taken mercury to affect the constitution as much as the opium did, the venereal disease must have been nearly cured, or at least much lessened ; but as that was not the case, it convinced me that the opium had no effect whatever on the venereal disease. I then put her under a course of mercury, by friction, and in a short time it affected her mouth ; the sores soon began to look better, and they went on healing without interruption, till the disease was cured I may just observe, the inconvenience from the opium was not considerable, for although it kept her quiet, she was not constantly

Luke Ward was admitted into St. Bartholomew's Hospital January 12 1785; his complaint was an ulcer in the fitof three months' standing, which, both from its appearance and the symptoms which preceded it, seemed to be Cereal He was ordered two grains of opium twice a day, which he took a few days without any other effect than that of s eeping betteTat ni'ht han usual, when the dose was increased to twcfgrains three tTrfe a day. His throat now gave him lew nnin u,5 • • was no, found ,o be at alf n,e„deT ItoH v^ ysTe doTTa" increased to three grains thrir-P n Aw f„ .u-v nas m„e or no ioconveLnc: tZ^'Z^ aSow^ EFFECTS, ETC., OF THE LUES VENEREA. 309 his eyes were rather inflamed, and his face rather flushed. He continued to take this quantity for five days, and then it was increased to three grains four times a day. Next morning the redness and heat of his face were much increased, and had extended over his whole skin ; he complained of pain in his head. His pulse was full and strong; he was bound in his body, and his belly was tense and painful. The opium was omitted, and such remedies as the present symptoms seem to require were given, but without effect, all his symptoms continuing to increase till he died, which was on the fourth day after ; during this time the ulcer increased much, and the discharge of saliva was so great as to resemble a slight salivation. This case proves, in the first place, that the opium had no effect upon the ulcer in the throat; and, in the next, that it is a medicine capable of producing very violent effects on the skin, requiring therefore great caution in the mode of administering it. John Morgan was admitted into St. Bartholomew's Hospital with an ulcerated leg. The common applications were tried for seven weeks, at the end of which time he was in every respect worse, having no sleep from constant pain, and he was sinking very fast. Two grains of opium were given every two hours for twenty-three days; it made him hot and costive, and his pulse became strong and full, but without sleep or abatement of pain. The dose was increased to four grains every two hours in the day, and eight grains every two hours during the night. The effects were costiveness, retention of urine, loss of appetite, an inflammatory disposition, no sleep, without any amendment of the ulcer. On the third day of taking the last-mentioned quantities he awoke from a short sleep, delirious, and continued so for twelve hours, when it left him very weak, sick at his stomach, and with a low pulse. In three or four hours the delirium returned, and continued forty-eight hours; the pulse, on its return, immediately rose, and his strength returned to a very great degree. When it went off he fell into a sound sleep for about eight hours, and awoke very tranquil, though weak; no more opium was given, and the leg in the space of a month healed. In the first twenty-three days he took twenty-four grains a day; for the last three days he took seventy-two grains a day. In twentysix days he took seven hundred and sixty-eight, which is nearly two ounces of opium. . Sarsaparilla, from the comparative experiment made with it and the guaiacum, would appear to have no effect upon the venereal irritation itself, and therefore can be of no service till that irritation is destroyed ; and as mercury is the antidote to that poison, and becomes one of the causes of the complaints in which sarsaparilla is useful, therefore mercury is not only necessary to destroy the poison, but also assists m forming the diseases we are now treat.

ln1t°is easy to conceive it in many cases to be of use in preventing 310 HUNTER ON THE VENEREAL DISEASE. the formation of the disease arising from mercury. When given along with the mercury it is often joined with the gum guaiacum, or the wood of the guaiacum, which we know will have some effect. The sarsaparilla is generally given in form of a decoction, three ounces to three pints of water, boiled down slowly to a quart, and the half or whole is drunk every day, generally at three different times, often at meals. It is sometimes ground to a powder and taken every day with the same effect; but I should prefer the extract made into pills, as the easiest way of taking this medicine. In many of these cases I have seen good effects from the hemlock, of which the following is an instance; and I would further refer the reader back to my observations on this medicine, which I gave when treating of the disease produced in consequence of a bubo, p. 235. A poor woman had undergone repeated salivations, which had always relieved the most pressing symptoms ; but after that she was afflicted more or less for three or four years, ulcers broke out in her nose, and all over her face, with what is called a true cancerous appearance. The sores became soon very deep, and gave very considerable pain. Mercury, sarsaparilla, and bark were given, without effect; the sores getting daily worse, the parts affected were ordered to be held over the steam of a decoction of hemlock every four hours, and as much extract to be taken internally as the patient could bear. She had sleep, and was free from pain the first night; and in a few days the sores put on a healing appearance. She lost her nose and one side of her mouth; but in six weeks' time every part was skinned over. She remained well for three months, when the disease returned with redoubled violence, and soon destroyed her.

§ 2. Of the Continuance of the Spitting.

It sometimes happens that the spitting continues after there is every reason for supposing the mercury to be entirely out of the constitution. As it is only a continuation of an action, or an effect of mercury having been in the constitution, it is necessary to distinguish it from the original, or from the immediate effect of mercury ; since on this distinction rests the method of cure. Such constitutions have been generally supposed scorbutic; and where there is a great susceptibility of the mercurial stimulus in these parts, the salivation will continue for months after the mercury has been completely removed ; but this medicine not being given now in quantity sufficient to produce such violent effects on the salivary glands, these cases seldom occur. In such cases I would recommend strengthening diet and strengthening medicines. Sea-bathing is one of the best restoratives of relaxed habits, especially after mercury. Mead's tincture of can~ thandes is supposed to be of service in those cases. OF PREVENTING THE VENEREAL DISEASE. 311 The alveolar processes have sometimes become dead, and exfoliations have taken place; and this alone has kept up a discharge of saliva. When this happens we must wait till separation takes place, and extract the loose pieces, after which the salivation will subside. . T t I have seen part of the jaw exfoliate from this cause. In most cases the teeth become loose, and in many they drop out. CHAPTER V.

OF PREVENTING THE VENEREAL DISEASE.

As diseases in general should not only be °^* ^."Je"

%&ed on a dry par,, stick ,;it and preventanything that

^oSn iJ^d «££ffitt ^ — to touch tbe

51ts^srSSs6^^^^^0/ the poison : the alkali must be much diluted, or it will excoriate.

\r^z^%™*$^«",here wou,d be sti" more security. b t * rain 0r two to eight 312 HUNTER ON THE VENEREAL DISEASE. PART VII. CHAPTER I.

OF DISEASES RESEMBLING THE LUES VENEREA, WHICH HAVE BEEN MISTAKEN FOR IT.

There is probably no one disease to which some other may not bear a strong resemblance in some of its appearances or symptoms, whereby they may be mistaken for each other. The situation of a complaint also may mislead the judgment. A lump, for instance, in the breast of a woman, may resemble a cancer so much as to be mistaken for one, if all the distinguishing marks of cancer are not well attended to. An ulcer on the glans penis, or in the throat and nose, creates a suspicion of the venereal disease. Even the way in which a disease is caught becomes a cause of suspicion. The fluor albus in women sometimes produces a simple gonorrhoea in men. Drinking out of the same cup with a venereal patient was formerly supposed to be capable of communicating the lues venerea, but this notion is I believe now exploded. Of late years a new mode of producing the venereal disease is supposed to have arisen; this is by the transplanting of a tooth from the mouth of one person into the mouth of another. That such practice has produced diseases is undoubted, but how far it has been venereal remains to be considered. Diseases which resemble others seldom do it in more than one or two of the symptoms; therefore, whenever the nature of the disease is suspected, the whole of the symptoms should be well investigated, to see whether it agrees in all of them with the disease it is suspected to be, or only in part. This observation seems to be more applicable to the venereal disease than any other, for there is hardly any disorder that has more diseases resembling it in all its different forms than the venereal disease; and when a disease resembles the venereal in some of its symptoms, but not at all in others, then those other symptoms are to be set down as the specific or leading ones of the disease to which it belongs, the resembling symptoms to the venereal being only the common ones. But if a disease is suspected to be venereal, though it is not perfectly marked, yet if it resembles the venereal in most of its symptoms, it must be supposed to be venereal, that being the most probable, OF DISEASES RESEMBLING THE LUES VENEREA. 313 although it is by no means certain; for probably the venereal can hardly be demonstrated in any case, especially in the form of the lues venerea, from its not having the power of contamination.*

* [There has been much confusion respecting syphilitic and pseudo-syphilitic diseases, which would have been in a great measure avoided had due attention been paid to the obvious principles which should determine the identity or diversity of diseases. This confusion is in a very slight degree chargeable on Mr. Hunter. Yet there are a few instances where he seems to have been misled by preconceived opinions respecting the venereal diseases, which a longer observation would have shown him were more than doubtful. Diseases may be confounded with syphilis which have no connexion with any virus whatever. This is frequent in sores on the genitals, where superficial excoriations, which by proper treatment may be healed in three days, and herpetic vesicles, which exactly resemble in their appearance and course those which so frequently occur on the lips, have been often erroneously treated as venereal. The same observation applies with equal force to some forms of sore throat and cutaneous eruptions. . . The existence of a morbid poison as the cause of lues venerea is interred trom two facts. In the first place the primary symptoms have been ascertained by loner observation to be the consequence of communication with infected persons, and°to be capable in the same way of infecting others. In the second place, these primary symptoms have been observed to be followed after an interval ot time bv secondary symptoms. It is true that in practice the nature of the case precludes us from obtaining full proof of these points in every individual instance, and we are forced to determine the treatment on probable conjecture rather than on certainty. But they have been ascertained to be generally true ot the class of symptoms which is called venereal. It is on their truth that the received opinions of the pathology of the disorder rest, and in a medical argument, unless oSe or both of them is satisfactorily ascertained, it cannot be denied that we have no adequate proof of the existence of any vims at all. # The mode in which the disease has been derived, if it exists alone, may mislead, since there may be irritating qualities in the secretions of diseased parts, which may affect the parts to which they are applied, without the existence, of.any ■distinct morbid poison capable of generating a specific malady. Unless, therefore he exact identity of the symptoms in the party which communicates and the party which receives the infection is fully shown, or unless the miction can be Traced throuah several successive individuals, some uncertainty affects the conclusion But where the regular sequence of secondary on primary symptoms is uS^btedly e.tabll.hed, it's difficult to avoid the "^""^^f^'. distinct virJs, which^^^^^^^t^^e^,^^^ °fWK f vTheen so ftSael^iaoted from^elsus and others, as proofs of the which have been s^queniiy q opebeforethe close of the fifteenth century, existence,o the venerea ^^ £ hose who come in contact with the di£L°et-V-e emirely sLnt as to an'y constitutional affection being the consequence of the local malady _g pr0Ved, it may still be questioned But where the existence ^t a p v venerea ; and this question can whether this poison is thsme *.«. ^ q{ communication, the character only be answered by » °°™P^bd° ress of the disease, and the mode of cure. of the symptoms, the course ana P syphilis, we can scarcely doubt the Where these are the same as are touna ,, , ^.^ difference under

identity of the virus; ^/'^f^^y infer a diversity. similar ™™™tm^Z£™X™n**oT>B of the venereal disease itself will Hence any error or n™c™J '„ of the diseases which resemble it, and lead, infallibly affect °« ^^V Jnd bias of the individual, either to the undue according to the Pr®P° TimiSSon of the term. Of late years the most frequent extension «r the undue hmitation a/e manifestly syphilitic, 314 HUNTER ON THE VENEREAL DISEASE. Although the venereal disease keeps its specific properties distinct in its several forms, yet its symptoms are in appearance cornon account of some difference from the preconceived opinions which have been formed of lues venerea. Writers on this subject seem scarcely to have been aware how various are the appearances of venereal symptoms, and how different atdifferent times is the effect of remedies. A primary sore, in which the characters of a chancre as given by Mr. Hunter are not obviously visible, may nevertheless be venereal. It may be derived from a venereal sore, and may produce constitutional symptoms which have every character of genuine syphilis. In secondary affections the variety is still greater. Symptoms of a doubtful character are frequently so intermixed with others, which it is impossible to mistake, as to be certainly attributable to the same cause. Hence when we meet with deviations from those forms of the disease which are most peculiar and most characteristic, we are not warranted in inferring a diversity of cause, or ascribing the symptoms to the existence of a different virus from that of genuine syphilis. Yet many histories have been given to the world as pseudo-syphilitic in which the appearances exactly accord with some forms of the lues venerea. Again, the notions which have prevailed as to the mode of cure has been a still more fertile source of error. Mercury has been considered as the only cure of syphms, and its action has been taken as the test of the nature of the malady. Where on the one hand mercury has disagreed, or where on the other the patient has recovered without resorting to its use, it has been inferred that the disease has not been venereal. Yet it has been fully established by the experience of former ages, confirmed as it has been by a long series of experiments which have been recently instituted, that most if not all venereal symptoms, whether primary or secondary, may be subdued without the use of mercury. It is not necessary to refer to these experiments in detail. They are well known ; and the conclusion which has been drawn from them is irresistible, or at least there are no sources of error which can materially impeach its general truth. On the other hand, the unfavourable action of mercury is no proof that the disease is not venereal. Many circumstances pay interfere with its effect as an anti-syphilitic, and render it inert or injurious in cases which are truly venereal. When it.produces no sensible effect on the system, it frequently has no action also on the venereal symptoms. When it produces vomiting, or dysentery, or erethismus, or materially deranaes in any way the health, venereal symptoms will usually spread under its use. Cases fZhn/^CCUTnng 10 ^Cil 4l/e s»bseque"t progress of the malady proves the hnLh „♦ V1,eW ? ln uWh'Ch the Ultlmale cure is effected by means of mercury, "= T°"e 1™ " haS senous,y aggravated the affections it was employed venerPa J„T ^T a Prac,t,cal knowledge of the course and aspect of lues hrwiirbP,taZgU.ld^heKJUrg,ment- Jf ^e practitioner has not this knowledge, of Tnv nntnS "V"8 belleJ".t° the ™^ of the disease on the occurrence 2hZr7fhyrpt0mVnd W,U USU3lIy abandon the mercurial treatment confdenceinLaf.,aS ^r" accluai"'ance with the malady as to give him

dec^^ »««?". »•«? been usually placed are tuted. The answer is plain Wh^igr0U-dS °I-1,sc"mination can be substiof effects is not SentTor oSSon^bat" con^T" f "^ the differenCe can arise as to the diversity of measles and mT "?£ nnlfo™- No doubt DISEASES RESEMBLING THE LUES VENEREA. 315 mon to many other diseases, and in that light it cannot be said to have any one symptom peculiar to itself. For instance, every symptom of the venereal disease, in form of a gonorrhoea, may be produced by any other visible irritating cause, and often without any cause that can be assigned ; even buboes and swelled testicles, which are symptoms of this disease, have followed both stimulating injections and bougies when applied to the urethra of a sound person; and indeed these two symptoms, when they do arise from a venereal cause, in many cases are only symptomatic, not specific, but more especially the swelled testicle. Sores on the glans penis, prepuce, &c, in form of chancres, may, and do arise without any venereal infection, although we may observe that they are in general a consequence of former venereal sores which have been perfectly cured. The symptoms produced from the infection, when in the constitution, are such as are common to many other diseases, viz. blotches on the skin are common to what is called scorbutic habits ; pains common to rheumatism, swellings of the bones, periosteum, facias, &c. to many bad habits, perhaps of the scrofulous and rheumatic kind. Thus most of the symptoms of the venereal disease, in all its forms, are to be found in many other diseases; therefore we are led back to the original cause, to a number of leading circumstances, as dates, and its effects upon others from connexion when only local, joined with the present appearances and symptoms before we can determine absolutely what the disease truly is; for all these taken together may be such as can attend no other disease. However, with all our knowledge, and with all the application of that knowledge to suspicious symptoms of this disease, we are often mistaken, often calling it venereal when it is not; and sometimes supposing it to be some other disease when it is venereal. Rheumatism, in many of its symptoms, in some constitutions, resembles the lues venerea; the nocturnal pains, swelling of the tendons, ligaments, and periosteum, and pain in those swellings, are symptoms both of rheumatism and the venereal disease when it attacks those parts: I do not know that I ever saw the lues venerea attack the joints, though many rheumatic complaints of those parts are cured by mercury, and therefore supposed to be venereal.*

of the poison of glanders on the human subject, cannot be confounded with syphilis because the symptoms are different; and this difference, which may be traced uniformly through a series of individuals affected by these maladies, prevents the possibility of attributing them to the same cause. The peculiarities which have been supposed to take the cases described as pseudo-syphilitic out of the class of syphilitic diseases are uncertain and variable, and can never constitute the distinctive characters of a separate and independent malady.] * TThe statement seems to be too general. Cases occasionally, though rarely, occur where inflammation of the synovial membrane of the joints shall take nlaoe in union with secondary symptoms of lues venerea of an undoubted chart hall increase in severity during the increase of the other symptoms ; and shall 'subside as soon as mercury is sufficiently used, and the eruption or sore 316 HUNTER ON THE VENEREAL DISEASE. Mercury, given without caution, often produces the same symptoms as rheumatism ; and I have seen even such supposed to be venereal, and the medicine continued. Other diseases shall not only resemble the venereal in appearance, but in the mode of contamination, proving themselves to be poisons by affecting the part of contact, and from thence producing immediate consequences similar to buboes; also remote consequences similar to the lues venerea. As errors in forming a judgment of a disease lead to errors in the cure, it becomes almost of as much consequence to avoid a mistake in the one as in the other; for it is nearly as dangerous in many constitutions to give mercury where the disease is not venereal as to omit it in those which are; for we may observe, that many of the constitutions which put on some of the venereal symptoms, when the disease is not present, are those with which mercury seldom agrees, and commonly does harm. I have seen mercury, given in a supposed venereal ulcer of the tonsils, produce a mortification of those glands, and the patient has been nearly destroyed. When treating of the lues venerea, and giving the symptoms and general appearances of the disease, I related some cases which appeared to be venerea], though they really were not, and I shall now refer the reader to these, as it will be unnecessary to give them again here, although if they had not been formerly taken notice of, this would have been a very proper place. As the diseases in question are various, and not to be reduced to any system or order that I am acquainted with, I shall content myself with relating the cases, and thereby put in the power of others to judge for themselves, if they should not be inclined to adopt the conclusions J have drawn from them. On the 28th of July, 1776, a gentleman, then in the West Indies, scratched the end of his finger with a thorn. On the 31st he opened an abscess on the shoulder of a negro woman who had the yaws, and had been long subject to such abscesses in diflerent parts of the body, and to incurable ulcerations afterwards. At the instant after the operation he perceived a little of the matter upon the scratch, and exclaimed that he was inoculated. On the 2d of August he amputated a boy's finger, of thirteen years of age, for a sore resembling wormeaten wood. The scratch on his finder did not heal, but from time to time threw off whitish scales : this appearance alarmed him and he rubbed in mercurial ointment very freely Notwithstanding this, in the month of September, a painful inflamed throat are controlled by its exhibition. In such cases the synovial inflammation has an acute character; and is attended with a degree of pain and teS and fh"PtlCpa ff r6SS' WhhlKh Sufficie,,t'y distinguished it from that Snauidfo™ of the same affection which is common under circumstances of gene?al cachexia

uHtvery function necessary for fZZtlT^of n riS ZZt^ltZ WeTscS^' ^ ,hC PaUent haS been reduced t0 a sta* whichfdS5y retem! DISEASES RESEMBLING THE LUES VENEREA. 317 tumor appeared on the second joint of the finger, which was soon followed by several others on the back of the hand, in the course of the metacarpal bone of the forefinger. He still continued the mercurial friction, but without effect, for the tumours daily multiplied, and by the month of November extended to within a small distance of the axilla. They did not go on to suppuration at this time. About the end of November he began to be affected with severe nocturnal pains in different parts of the body, but especially along the tibia and fibula, with frequent severe headaches, which continued to increase to an almost intolerable degree for five months, though he used mercurial friction, with decoction of sarsaparilla, every day in great quantity. . . In the month of May, 1777, a scabby eruption appeared in different parts of the body, especially the legs and thighs, and the before-mentioned tumours ulcerated; but this was followed by a remission of the nocturnal pains. He could never bring on a salivation, though his mouth was constantly tender, even for months. The ulcerations became daily worse, and a voyage to England was thought the only resource. He arrived in London the first of August, and by the advice ot Dr. William Hunter and Sir John Pringle, he began again a course of mercury and sarsaparilla, with a milk diet. I was called in, and judging that two thirds of a grain of mercurius calcinatus, every dfy, was too small a dose, if it were judged to be venereal it was ordered to be gradually increased to five grains; and he continued this course till November, when all the sores were perf6He ^discontinued the mercury, and reJmained+,freet.,from^|} symptoms of the disorder, except some nodes on the tibia, and rheumatic pains on exposure to cold, until about welve months ago * when he began to have an uneasiness in swallowing, a rawness in the throat, and a discharge of vtscid mucus from that and the posterior nostrils, all of which still continue. The following observations may be made on the above case. There can b? little doubt that, the disease was the yaws. The v.wf^e a disease that resembles the venereal in several of its

s=A scum *2 -Sr^^Knstate favourable tc, general healthy Thus u»gn> ^ g^ a the disease must do' llttl« °J ™hese circumstances, he commonly belter d et than usual Undet me ^ unfavouraye

£ will conTuetuch ,oTge, Various medicines are given for ,- • f iUe work was published in 1786, consequently it would * [The first edition of th work w■ v ^^ ^ ^ qj. ^ ulceratlon8 318 HUNTER ON THE VENEREAL DISEASE. the cure, but it is not clear that any of them do good. Mercury has considerable power over the disease, without being a specific for it. If given early it will either check the progress of the disease, or perhaps even heal up all the sores on the skin; but nothing is gained by this, for the disease soon breaks out anew. Some practitioners of medicine in the West Indies are of opinion that interrupting the course of the disease by mercury is productive of no other evils than those of loss of time and an imperfect cure; others affirm that it is often the cause of what they call the boneache. Towards the end of the disease it is generally allowed that mercury may be given safely, and even with advantage. It is probable the long continuance of the disease, being above fourteen months, and also the pains in the bones in the present case, were owing to the very early and free use of mercury. It may be allowable to add, that the yaws do not differ more from the venereal disease in curing themselves than in this circumstance, that, like the smallpox, they affect none a second time.* A gentleman applied to me for the cure of chancres, seated on the attachment of the prepuce to the penis, and also on the fraenum. Mercury was used chiefly by friction, in order to affect the constitution; it was also applied to the sores, in order to affect them locally. The cures of the chancres went on gradually and without interruption; and in about five weeks they were perfectly healed. He almost immediately had connexion with a woman, and long before we could suppose the mercury had all got out of his constitution. In a very few days after the "first connection, the prepuce began to be chopped all round on the edge of its reflection. He continued his connection, and upon its growing worse he applied to me, and I found the chops very deep, and the prepuce there so tight and sore that he could not bring it back upon the penis. The question now was, whether this was venereal or not 1 The sores themselves did not appear to be so; but more was to be taken into the account than simply appearances. It was first to be considered whether it might possibly be a return of his former complaint. This could not be the case, because the sores were not in the same parts. It was next to be questioned, was it possible for this part of the prepuce to have been contaminated at the same time with the former, and the poison not to have come into action till now, having been prevented by the course of mercurv, which had not cured the disposition ? This could not be well answered, although not probable because the poison appeared to come too soon into action after leaving off the medicine; for I did suppose there was still a C tf Ti °/ ^u?? l? the constituti°n- Was it then possible for him to have caught it from the woman ? This, I supposed could not have been the cause of these chops, whatever XSKo"

the#S^^ fven in the fifth volumeof name of Home. The case related bv^r AH attrib.ute?. t0 a gentleman of the sons, as occurring at Madeira, S^ tolSb'een l^™^^ DISEASES RESEMBLING THE LUES VENEREA. 319 nexion might have to render them venereal hereafter; for they appeared too soon after it, especially as he had mercury in his constitution at the time, and as the parts had been accustomed to the application of venereal matter but a little time before. Although, from all circumstances taken together, I was convinced the case was not venereal, yet an apprehension arose in his mind concerning the possibility of having given it to the lady, as he had connection after the first appearance of the sores. I was equally convinced of the impossibility of the one as the other, therefore desired him to rest easy on that head. He went immediately into the country, and nothing being done for those chops, they got perfectly well. In less than a fortnight after this connection, the lady became a little indisposed with a slight fever, and a swelling came in one of her groins. I watched the progress of this swelling, which was slow, and I did not believe it to be venereal. It at last formed matter and broke, and a poultice was applied to it. Instead ot ulcerating or spreading, it rather had a healing disposition, and in about six weeks it was perfectly well. While it was healing, scurfv eruptions came out on the skin, some on the face and thighs, but more especially on the hands and feet, where the cuticle peeled off. Upon the first appearance of these I was a little staggered ; but, as the sore was healing, I was unwilling to give credit to the appearance, and therefore begged that nothing might be done; and they all got well. ,. From the general outline of these cases, one would naturally have said they were venereal; but the particular circumstances being all investigated, and the whole taken together, led me to suppose that they were not, and the event proved that to be the case. The following case was communicated by Mr. French, ot Harpur-street. . "June the 9th, 1782, a gentleman applied to me for an ulcer which was seated on the glans penis, attended with excessive pain. Knowing him to be an intemperate man, and learning from himselt that during a state of intoxication he had been connected with a woman, I mdged the complaint to be venereal. He was now in a feverish state, and unfit for the exhibition of mercury: I therefore prescribed for him decoction of bark, with elixir of vitriol and tinctura thebaica, proportioned to his pain. I directed him to abstaTn f om ever/kind of fermented liquor, to live chiefly upon milk and to wash the ulcer with a liniment composed of equal narts of oil of almonds and aqua sapphmna. P« About the 17th of the same month, some check having been ■ ♦ thl frvpr the sore looking cleaner, and his pain having

f^I^^'^^ d0SGS °f argentUm ViVUm Snd eXtmCt of hemlock mercurial course to disagree, I ordered "Julythe 4«'™1°|lract 0f hemlock to be taken two or three three grains ot l^ Tcoction 0f bark to be taken as before, with timeS. a^nn,aonf tinctura thebaica, which was gradually increased twenty drops ui " to sixty, at bed-time. HUNTER ON THE VENEREAL DISEASE. " The ulcer had spread very much during the mercurial course, and had now destroyed half the glans penis. " October 1st, Mr. Hunter was consulted, and ordered the patient to add the powder of sarsaparilla to the decoction of bark, to take laudanum freely, and wash the sores with tinctura thebaica. Soon after beginning this course the remainder of the glans penis sloughed off, the parts gradually healed, and health was restored. " There were two other symptoms in this case which deserve to be taken notice of: a considerable enlargement of the scalp on the right side of the os frontis, and on the left parietal bone, attended with excessive pain, and vibices resembling the sea-scurvy on the inside of the left tibia, both of which disappeared in the course of the cure. " Some months after, the tumor in the head returned, and several abscesses were formed, which were opened, and the cranium found carious to a great extent. On account of the pain, he has for some months past taken two hundred and forty drops of laudanum and six grains of opium daily. These sores healed up, and others broke out in different parts of the head, which also got well; and in June 1785, there was only one lange ulcer in the angle of the right eye." A lady was delivered of a child on the 30th of September, 1776. The infant being weakly, and the quantity of milk in the mother's breasts abundant, it was judged proper to procure the child of a person in the neighbourhood to assist in keeping the breasts in a proper state. It is worthy of remark that the lady kept her own child to the right breast, the stranger to the left. In about six weeks the nipple of the left breast began to inflame, and the glands of the axilla to swell. A few days after, several small ulcers were formed about the nipple, which, spreading rapidly, soon communicated and became one ulcer, and at last the whole nipple was destroyed. The tumor in the axilla subsided, and the ulcer in the breast healed in about three months from its first appearance. On inquiry, about this time, the child of the stranger was found to be short-breathed, had the thrush, and died tabid, with many sores on different parts of the body. The patient now complained of shooting pains in different parts of the body, which were succeeded by an eruption on the arms, legs, and thighs, many of which became ulcers. She was now put under a mercurial course, with a decoction of sarsaparilla. Mercury was tried in a variety of forms: in solution, m pills internally, and externally in the form of ointment. It could not be continued above a few days at a time, as it always brought on fever or purging, with extreme pain in the bowels. In this state she remained till March 16, 1779, when she was delivered of another child in a diseased state This child was committed to the care of a wetnurse and lived about nine weeks; the cuticle peeling off in

Tld dS d ' & Y erUpti°n coverinSthe wh°k body The DISEASES RESEMBLING THE LUES VENEREA. 321 Soon after the death of the child, the nurse complained of headache and sore throat, together with ulceration of the breasts. Various remedies were given to her, but she determined to go into a public hospital, where she was salivated, and after some months she was discharged, but not cured of the disease. The bones of the nose and palate exfoliated, and in a few months she also died tabid. Of the various remedies tried by the lady herself, ndne succeeded so well as sea-bathing. About the month of May she began a course of the Lisbon diet-drink, and continued it with regularity about a month dressing the sores with laudanum, by which treatment the sores healed up ; and in September she was delivered of another child, free from external marks of disease, but very sickly ; and it died in the course of the month. About a twelvemonth after, the sores broke out again, and, althouo-h mercurial dressings and internal medicines were given, remained for a twelvemonth, when they began again to heal up.*

* [The author is evidently of opinion that these and similar cases are not venereal, and he elsewhere denies it to be possible that an infant can be contain mated by is parent before its birth. Whether he is right in this opinion must be juydgedPby ?he following statement of the facts, which are sufficiently frequent and Deculiar to be ffiven with confidence in their truth. When a mother suffers during the period of pregnancy from a constitutional venereal affection, she seems to°be particularly disposed to miscarry. The aborlion seems to be caused by the death of the infant which is very generally born deS! and has usually ceased to show signs of vitality for some days before

^'ifhowever, miscarriage does not take place, it is most usual that the infant at buthThows n™ signs o°f disease. But at a variable period generally from Sree to five weeL ffter birth, it becomes slightly indisposed. Then eruptions a£ pear about thlthicrhs and the groins, between the nates, or on the pudenda. They wTar the Lpec tof discoloured patches, generally affecting a circu ar form with Tshninr/ surface, and some slight desquamation, but without the least tubercuhthickLin. As the diseaseDproceeds these patches enlarge, and eventually occuDvaTmoR the whole body; and in the folds they sometimes slightly exco- ?SePLd even, neaTthe anus, at the umbilicus, or on the female pudenda, form "mall condvlomatous excrescences. Then ulcers in many cases take p ace in the small conayioin<Huu= throat- the nostrils are partially obstructed by interior o themou th nd ,nhe throat .the nj^ J^ ^ ^^ an increase ot their »e°™"» ' F h first appearance of the all this there is much^genera ^P0^10^^ continue it h™meB very weak symptoms ^e ^^^UTglected it often terminates fatally, but under ^^TeXtur^U t?eSesymPtogms are readily subdued, and perfect health

may be restored. _ contact with a child thus diseased may be conta- Those who come into dose con ^.^ ^ ^^ .^ ^ .^.^ of the mouthi minated in consequence. " f a heaithy woman, it is very common that and in this state sucks the ^ea>c _ ^ ^ ^^ wm noJ. re3emble the fissures the nipple should become ™°r™ Vg of women who give suck, and which which are so common on ;ne , {£,ce but will be a corroding ulcer, and will usually occasion no oss oi ^ ^ ]q before u is hea]ed- It also destroy the whole or the greaie j d -n thg ^^ whi(jh) hoxvever, rarely produces in general an eniarg s ^ ^ ^^ ^^ sqvq ^^ erupt10ns, passes into.suPP^0"^ i„n0 respect distinguishable from the common forms

of "ues3venerea. been thus infected by a child which she has suckled, If a woman, who nd*> " ^g* 322 HUNTER ON THE VENEREAL DISEASE. The following cases, being all derived from one stock, show as much as possible that new poisons are rising up every day, and those very similar to the venereal in many respects, although not in all: therefore it is the want of similarity that becomes the criterion to judge by, and not the similarity. The parents of the child who is the subject of the following history were and are to all appearance healthy people. The child was weakly when born; and the mother having little or no milk, when it was three weeks old she gave it to a nurse whose milk was then seven months old and was giving suck to her own child. The foster mother allowed her own to suck the right breast, while the other sucked the left. The nurse observed that the skin of the foster child began to peel off; but no rawness or soreness took place except about the anus, where it looked as if scalded. The same kind of peeling took place on the lips, but they did not appear to be sore, although the people in the country said it was the thrush. The inner surface of the mouth and tongue appeared sound. In a fortnight after her receiving the child it died, and then she allowed her own child to suck both breasts for three weeks; at the end of which she came to town to nurse a gentleman's child. She gave suck to this second child ; but after being in town about ten or eleven days, she did not feel herself perfectly well: which made them suppose that the new mode of life, confinement in town, and probably better living, might not agree with her, and she went into the country and took the gentleman's child with her. About three or four days after she went to the country, for instance,

suckles also another child which is healthy, no infection will be communicated, provided the sound child is kept carefully to the opposite breast, and is never allowed to take into its mouth the nipple to which the diseased child is applied. But if this precaution is not taken, and the children are applied indiscriminately to either breast, the sound child will contract sores in the interior of the lips, and these will be followed by scaly eruptions on the skin, exactly resembling those which are seen in an infant which has received the infection from its mother. It would be easy to substantiate what has been stated by the recital of cases. lhe results are tolerably uniform; at least the deviation from the ordinary course are not greater than those which occur when the venereal disease is communicated in the usual way by sexual connection. It is difficult, in the face of these facts, to deny that such cases are the effects of the venereal virus. It is true that the symptoms in children are not precisely ton^T/ -m TT6 °r.aPPeara"ce with the most usual symptoms of the neon IrirSrn ^ ,D:SeaSf °f the bones or Periosteum seem never to occur, nor are the eruptions tubercular. Yet as the symptoms in the adult from whom the disease is received, and the adult to whom i is communicated are d£eci& * -sArsnit til a dSSSy of virus ^ ^ ^ Clrcum^ances of an infant, and not to It is impossible to admit the amnmon* .,,, j u ,i symptoms never contaminate andTerefore th^ Z,?6 "fr that,seconda'y facts are so well established thaYit is morp }LT* mUSt \° m,staken- Th« he has laid down than to doubt the fact™ qUe8UOn Finciple Whi<* DISEASES RESEMBLING THE LUES VENEREA. 223 about a fortnight after she took this child, and five weeks after the death of the first child, her left nipple, which the first-nursed child had always sucked, began to be sore, so that she could not let the child suck it. This ulcer on the nipple became extremely painful; in a day or two eruptions came out on her face, and soon after all over her body, but most on her legs and thighs. They continued coming out for about a fortnight, and had at first very much the appearance of the eruptions of the small-pox, and on the third day of their eruption were attended with fever, universal uneasiness, and great pain. Two or three days after the eruption on the skin appeared, one of the glands of the arm-pit began to swell, and formed matter, and was opened within a fortnight after its first appearance, and healed almost directly. Some of the eruptions increased fast and became very broad sores, nearly of the size of a half crown, especially on the legs and thighs, and were covered with a broad scab; many remained small, and only appeared like pimples. About a fortnight after the first appearance of the eruption, some began to die away; and in four weeks more after this appearance, a foul ulcer attacked the left tonsil. The surgeon in the country, from all these circumstances, finding he could not get any ground by the before-mentioned treatment, determined to give her the solution of the corrosive sublimate, of which he gave half a grain in solution night and morning ; in about a week there seemed to be a stop put to the swelling of the ulcers, and the discharge to be somewhat lessened, the ulcer in the throat putting on a better appearance. It was at this period I first saw her, which was about six weeks after the first appearance of the eruption, and a fortnight after the appearance of the ulcer in the tonsil. The eruptions were then very much as before described, but the ulcer in the tonsil was clean and healing. From the history of the case I did conceive it not to be venereal; I therefore desired that all medicines might be left off, which medicines could only have been taken for a fortnight at most, because it was after the appearance of the ulcer on the tonsil the mercury was given, which was only of a fortnight's standing when I saw her. She soon after recovered. After being well for some time she again applied to the surgeon in the country, an abscess having formed where the complaint first began in the breast, attended with fresh eruptions on the face. The abscess was opened, and it healed up in a few days, and upon taking some cooling physic the eruptions disappeared She has continued very well'ever since without any other bad effect than the total loss of her nipple. This case was certainly under-

81 AtoutteTyrafter the appearance of the eruption on the nurse, ♦u L^L'* ,-hild was taken away and given to a healthy woman the gentleman schd^ a twenty-four year^ and who had lain •n wi* hex fiS?l3SEW™ months when she became wetnurse 324 HUNTER ON THE VENEREAL DISEASE. to this child. After a few days she observed eruptions on the child's head, not unlike those already described on the first nurse which it had sucked. Its mouth soon after became excoriated, so that it sucked with difficulty. After a short time those eruptions on the head became dry and peeled off, others appeared on the face, knees, and feet, but wholly unlike the former, as the first maturated, while the latter appeared only cutaneous, peeling off and leaving a circumscribed spot of a light dun colour, which continued increasing for five weeks. These eruptions continued nearly three months from their commencement, at which period the child was extremely emaciated; but no particular treatment was indicated, so no medicine was exhibited, and in a few weeks after it came to London and got perfectly well. The second nurse, a few days after giving suck to the child, had blotches appear on her left breast, precisely the same with those on the first nurse, with this difference only, that they were fewer in number, and attended with a greater degree of phlegmonous inflammation. They continued, and increased in size for seven or eight days ; then the nipple of the same breast became ulcerated, the ulceration spreading so much as to endanger the loss of it: her thighs now became diseased, and afterwards her legs. She suckled this child about twelve weeks. The disease seemed no longer to increase, and in twelve or fourteen days after this entirely disappeared, without her taking any medicine, except a few ounces of the decoction of the bark. The only application to the breast was unguentum simplex. The milk at this time became so small in quantity that they were under the necessity of providing a third wetnurse for the child, and the second returned to the country. Her own child being weaned, she had no further occasion for the milk, and in a few days it wholly disappeared ; but by way of amusing the child when peevish, she allowed it to take the nipple which had been diseased in its mouth; the consequence was, that in a few days this child also became diseased in like manner with the former. She now applied to an eminent surgeon for assistance, who, not being acquainted with the history, supposed it venereal, and ordered a colourless medicine, supposed, from circumstances, to be the solution of sublimate, sixteen grains to half a pint of water ; the dose a table-spoonful. She took this medicine as directed, and also gave it to her husband and child; the child a tea-spoonful only at a time. While taking this medicine she got well. The third wetnurse, like the former, was in a short time affected, but the blotches in this case were still fewer in number, the disease appearing to lose considerably in its power, as each fresh infection became less malignant than the former. She got well without taking any medicine.* * Added : « The following case shows the effect of the state of the mind upon the body, and the bad consequences attending the patient's being indulged in his DISEASES RESEMBLING THE LUES VENEREA. 325 § 1. Of Diseases supposed to be Venereal produced by Transplanted Teeth.

Since the operation of transplanting teeth has been practised in London, some cases have occurred in which the venereal infection

own opinions respecting the nature of a disease. It is given as drawn up by himself for my opinion. " ' In May, 1789, when in London, I was unhappy enough to have connexion with a woman of the town. Five days after I took more than usual exercise, and the day being warm I perspired profusely. This affected my head, more particularly my forehead. In this situation I went into the country, and while on the road the sweating'increased ; when it went off it left a burning heat about the forehead, so that I could not wear my hat. This heat continued all night, attended with an external pain round the forehead. The next day it increased, but the day after its violence seemed to lessen ; but it continued more or less tor several weeks. On my return home I was connected with my wife. « ' My mind became so much agitated that 1 found it impossible to be at peace till I unfolded my situation to a surgeon and apothecary. « 'I berran to fear that those affections of the head might arise from disease. The suraeon seemed to apprehend no danger. I pressed him t0Zlve™l*°™A opening^draughts, to carry off the inflammation about the head a"d ^"ered myself that they would also carry off any virus that I had contracted. Notwithstanding this, I still, however, found some of these disagreeable sensations, together with an uneasiness in the throat and teeth. « 'All this time there was nothing more than usual in the genital parts, but a degree of heat not felt or observed before. m;nnte 5 «I now conceived that this heat was increasing By a constant "d minute inspection, I found the size of the penis at tithes to diminish ; the nut assumed a pale yellowish colour, and the glands behind the nut seemed to^be^covered with mucus. The heat about the head diminished ; the throat and teeth telt

"Sourse of a fortnight after my return I persuaded "J*^^* give me small doses of calomel. For the first few days they worked me very violently. The quantity of calomel was then lessened. All this time eM discharge of any kind, but after taking those medicines a few days 1 telt some heat and pain in the groin, and the penis seemed at times hot, and I felt some

^^S course, and I now entered upon -me alteratives While taking° them my throat seemed to get worse and worse, but more so

^ix wBeek. after the connexion I was pronounced well, and left off all me-

'-Soon after this, in the mornings, prior »WS^™>Jtf^. small quantity of a whitish discharge on th > opening oHhe^ ^ .^ never in quantity so large as a pea, and ^ver but in the g

0{ih^^dZ^^^^f^^ ^ •**•orwith those assurances"; I therefore had the advice-of«M^™™ and that there was «.He said if I was affected £wa in *£ « which, he thought I no possibility of my »Wc?neT.Uich he would prescribe, for a fortnight and once. 326 HUNTER ON THE VENEREAL DISEASE. has been supposed to be communicated in this way, and they have been treated accordingly; nor has the method of cure tended to

or twice I discovered a discharge from the urethra, which was quite clear, and more glutinous than my water. This 1 always found was after erections. " 'The strengthening medicines were continued about a fortnight. My throat felt very sore at night, and looked Ted all round. A hard reddish pimple now appeared in the roof of the mouth. These circumstances made me very unhappy. "' I now began taking an electuary, like the former, and drank a pint of decoction of the woods every day. This plan was adhered to for six weeks. "' I took strengthening medicines for about a fortnight, and then left them off. "' I used a variety of things for my mouth and throat; onetime an electuary, and gargled with port wine ; another time I gargled with a decoction of roses, honey, &c. " ' I now find myself in a much worse situation than ever ; for although I have never been disabled from pursuing my business, I have some additional disagreeable sensations; very unpleasant feelings in the shin-bones, which affect me more after walking or standing, as if pins were pricking me. They are not violent, but disagreeable. My legs sometimes seem uncommonly stiff; there is a soreness in the knee, and in the hollow under the knee; a pain in the small of the back, sometimes in my arm. I think my corns, which are often troublesome, have been more so, especially in damp weather. " ' About three months ago I discovered a spot on the inside of the right thigh, the size of a shilling, which at times assumed a copper colour, but in common the colour of the skin ; but whenever heated it assumed this colour. On the other side several more, of a lighter kind, have appeared. There are several small ones, of the size of a large pin's head, about different parts of the bodjr, rising above the skin. There is no particular pain attends them. " ' Within this week some very large spots have appeared about the neck, and the right side of the neck feels sore at times. For some time past my nose and forehead have felt different from what they used to do. There has been a heat, attended at times with a pricking and throbbing pain, with a stiffness that I cannot descrjbe. The skin about the nose seems red. This instant there is a pain and stiffness felt in it. My eyes seem weaker than they used to be and sometimes look red. My mouth has been affected ; the membrane appears pale, and broken in some places. The saliva is very disagreeable : the breath is not offensive. Whenever I have wind in the stomach, my throat is very sore indeed. " ' It is necessary that I should observe that I am of a scorbutic habit, which has always thrown out pimples betwixt my shoulders, down my arms, and sometimes some few in my face. " ' When I returned home in May, I found my wife looking pale and weak. This I concluded to be the effect of breeding. It appears since, that on my return, she must have been advanced about six weeks in her pregnancy. I prayed the surgeon to tell me if he thought there was any danger of my injuring her, and that if there was, I would fling myself at her feet and inform her ofwhat had happened. This I also told the doctor; both assured me there was no danger. Towards the latter end of June she seemed to have a slow fever. The apothecary attended her. She appeared very weak. By degrees she got better. In July she received a terrible fright, so that she became very poorly a<rain ; was very weak, and complained of an unusual discharge from the vaaina.° For this, through much persuasion, I got her to consent to have the doctor's advice. I his I pressed very much, as he was acquainted with all the circumstances that had attended me. I was very apprehensive that her complaints were now the effec of an injury received from me. I told the doctor of the discharge, prayed him to give her symptoms due consideration, and pressed him to prescribe sJch medicines as would effectually remove the complaint. He attended her and assured me that there was not the smallest appearance of her complauTts a sing DISEASES RESEMBLING THE LUES VENEREA. 327 weaken the suspicion : yet when all the circumstances attending them, both in the mode of catching the disease, and in the cure,

from such a cause. He said they were the effects of weakness and pregnancy. She never complained of any pain in the parts, nor of any heat in making water. At this time she was troubled with an almost unremitting pain in her teeth, gums, &c. The doctor prescribed some strengthening cordial medicines, which she continued to take for some time. She grew better, but was almost continually affected with pains in her teeth. This discharge lessened by degrees. Her habit was always disposed to be costive, but more so when with child. This the doctor accounted for from her habit, her being with child, &c, and assured me that everything was perfectly natural, and that there was not the smallest appearance of anything arising from disease. About a month or more before she was brought to bed, those complaints in her teeth, ears, and head seemed to increase, a redness appeared over her eyebrows, where there was great pain, &c. «' At this time I observed some little spots about her face, of a yellowish colour, one in her forehead, two or three less near her ears, &c, and some few

°n» ^AUeneth she was brought to bed ; had afine child, perfectly healthy. Her teeth were still sore, the right side of her cheek so much so, that she could not bear it to be touched. Her left breast began now to be very troublesome, and the more so as the milk advanced. (In this breast she always complained of a pain from her first child, and sometimes she fancied she could feel a hard lump.) Both her nipples were very sore, were surrounded with little ulcerations ; but the left was by far the worst. It was very painful to her to give suck ; she was obliged to have her breasts drawn now and then Her nipples got better by degrees, and she now tells me they are well. There was early after she had children a redness betwixt the breasts ; but this also went oil. « ' There now seems a little redness on each side of her nose near her eyes, and sometimes the tip and sides of her nostrils appear red. She says there is no pain. Her pain is now in the left gums, and extends through to the cheek. He? water is frequently very thick, and there is, very soon after it is discharged,

with the snuffles to a degree that exceeds anything of the kind that I ever saw Tn any of our other children. I am always disposed to anticipate the worst and tuains me very much, lest it should arise from this general source of evil. ThPe "hildls heya"y thrives very well, .sleeps well. y°*M™B^Z£ home have now and then been poorly : in the corners of their mouths there was for weeks, an evident excoriation, assuming a whitish colour. This, 1 th nk, is now gone There seem some small pimples about .the: neck very sma 11 and therAre two or three of these sma 1 spots ^fi^^^^Si their noses are red and sore. Indeed my_mmu ii» situation is that I have by this unguarded act injure, m hole h ^^f ^^ truly wretched. I have made IfJ^^^iZefMen into bad hands. this disorder very early ; but, alas ;a^of 'estions of the first importance

^Iif^o^S Z^Z^ZX^o^e for me to have injured my

children by kissing:^^£*e%^ „oM it not most likely have produ'ce'd1 ffilfilSS or, would not my having received the lues into my habit prevent it! h & ]ikel t0 arise from thi8 cause ? " ' A^°n1rfDles nad been affected from the complaint, would the person.that If my wife's nipples haa how ^ . n what er uld her drew her breast be infectej ^ ,„ ^ ^ ^ ^ ^ be(jn the case , infection appear . 328 HUNTER ON THE VENEREAL DISEASE. when they have been treated as venereal, are considered, there is something in them all which is not exactly similar to the usual appearance of the venereal disease when caught in the common way; especially too when it is considered that some of the cases were not treated as venereal, and yet were cured, and therefore the cures of the others, which appeared to be from mercury, are not clear proofs of their having been venereal.* I believe that I have seen most, if not all, the cases of this kind which have occurred, and have attended some of them. In all of them the time of local affection, after the insertion of the teeth, has been almost regularly a month, which is too long for the venereal to take effect at a medium; and where they have produced constitutional symptoms, those again have either.followed the local too close for the venereal, or too regular as to time. But it may be advanced, that a disease has been produced probably as bad in its consequences as the venereal. That a disease has been formed in this way is certain. The first case of this kind which came under my care was a lady who had one of the bicuspidati transplanted. The transplanted tooth fastened very well. About a month after she danced till five or six o'clock in the morning, caught cold, and had a fever in consequence, which lasted near six weeks. In this time ulceration in the gum and jaw took place, though it was then not known. And when she was beginning to recover it was found that not only the gum and socket of this tooth were diseased, but also those of the teeth next to it. The two teeth were taken out," and the sockets of both afterwards exfoliated; but the parts were very backward in healing. This backwardness gave rise to various opinions, the principal of which was, that it was venereal. In the mean time a rising appeared upon one of the legs, which was of the indolent node kind; this was also suspected by some to be venereal, or rather was a corroborating circumstance of the former opinion; but I gave it as my opinion that- it was not. I desired she might go to the sea and bathe, which she did, and got perfectly well, both in the jaw and leg, and has continued so ever since. The second case of this kind I have seen was also in a young lady : the transplanted tooth fastened extremely well, and continued so lor about a month, when the gum began to ulcerate, leaving the

Can the child's snuffles arise from this cause ? Can any part be injured bv this complaint, without manifest inflammation, swelling, and discharge* * 'I have only to add, that I pray you, Sir, to be good enough to give this complex^unhappy case every necessary attention. I should wfsh forSitui!

.U on'my^STo""fe ti vel^ ^t^ ft""" °M%h* ^ S^ at and I believe we must a low, if ^Tdisease Zf ^T^ contamina^« > contracted from a lues venerea n the person fTnm IT^l' rt TSt have been for chancres are not common fnVemS and t^mi?K t0°th WaS taken ; tion. I believe few discharges diir^gSl&^p&XS ^^ DISEASES RESEMBLING THE LUES VENEREA. 329 tooth and socket bare. The ulcer continued, and blotches appeared upon the skin, and ulcers also in the throat. The disease was treated as venereal, the complaints gave way to this course, but they recurred several times after very severe courses of mercury: however, she at last got well. The only observation I can make on this case is, that the symptoms recurred after continued courses of mercury much oftener than is usual in venereal cases, and I had my suspicions all along that it was scrofulous. , , The third case was of a gentleman, where the transplanted tooth remained, without giving the least disturbance, for about a month, when the edU of the gum began to ulcerate, and the ulceration wen? ontm°the tooth§droPPeS out. Some time.after spots^appeared almost everywhere on the skin; they had not tne truiy CSia appearan/, but ™«^£%?J?&£. more circumscribed. He naa aiso <x u,iiuoi j hwdache

space of three years. ,ron~rPai ? The two first courses of Vrv: C°"'d 'hfJaeSreupt„Vse would' seem .cJ prove it was ; but mercury removing the eruptions wou coi;sisted 0f only ten the third course also »"9»^^ ™£h t0™ w that it could grains of corrosive ^'m^™ldea^nmces w&oh returned after

been given, would no. have yielded to^teii grams ^ Th! fourth case was that of a_young iaoy_w mentioned p,anted, and about the same "^ to u c^attand'the ulceration in the former cases 'he gum began to^cer , ^ ^ was making considerable progress di|le, , was afterconsulted desired mercury to be' fp™ '" Jy should not be wards desired to see her, »"* ad™ed ; the nature of the case; had recourse to, that we might ^f£' te adding one more for if she took mercury and got well, from such ,

* ^ T^^3^.^t*.nXsttusT ^ S wouW be produced by the removal of the first 330 HUNTER ON THE VENEREAL DISEASE. tooth was drawn, and the gum healed up as fast as any common ulcer, and has ever since continued well. This case requires no comment. I may, however, be allowed to observe, that if the lady had gone through a course of mercury, she would have, in all probability, also got well; for the tooth, in the time necessary for completing the course of mercury, would have dropped out; and if this had really happened, we need not hesitate in affirming that it would have been considered as venereal. The fifth case was that of a young lady, eighteen years of age, who had one of the incisores transplanted, which fastened very well; but six or seven weeks after the operation, an ulceration of the gum took place, the tooth was immediately ordered to be removed, and the bark was given without any other medicine, and she got well in a few weeks. The sixth case was that of a gentleman, aged twenty-three, a native of one of the West India islands, who had the two front incisors transplanted; and about the same time after the operation, as in the former cases, an ulceration of the gums took place, which increased to a very great degree, and the edges of the gum sloughed off. An eminent surgeon was consulted, who ordered the bark ; and the patient, without taking any other medicine, got well, in nearly the same time as the ladies in cases four and five, who had the teeth taken out. The gums recovered themselves perfectly, but were considerably shorter. If we take some of the above cases, and consider them as they at first appeared, we shall almost pronounce them to have been venereal. If we take the others, we shall pronounce them absolutely not to be venereal. And if we consider every circumstance relating to those probably venereal, we shall, as far reasoning goes, conc ude that they were not venereal. The first case that appeared at the time to be venereal is the second of those before related; but, as I did not attend the lady through the whole of the cure, 1 can say less upon it. She certainly had the symptoms recur £ tZ" a An ^ d° muvenereal cases in common, where the disease is attended with no ambiguity, and took more than the usual quantity undTr'ZTl, There.;s,theref0re in this case something not clearly "n ^,p™1 ! if-?" * d06S n0t GXaCt1^ aSree Wlth venereal cases in general in all its parts. The fourth case was similar in its recurring, and in the quantity of mercury that appeared to be necessary to remove the symptoms The most serious effects of transplanting a tooth happenedTa

toTfshtr^ii.fot™clua,:,,h^fedrfarce'defe,dme then begun to ulcerate As? L, I 8 n lheL gUm had ust be done, I desired him ,o male a sftons"VI7" 7=" Was best "> limate, and let the mouth be often washed wfth ft" I'/TT *t some lint, soaked in it, l0 tho part; ^t" L'SS'Xl"^ DISEASES RESEMBLING THE LUES VENEREA. 331 gress, she applied to Sir William Watson, to whose account of the case I must refer the reader, and from that account I must take my materials to reason upon. However, I may remark, that the case appears to have been supposed at last to have been venereal, whatever might have been the first opinion, and for the two following reasons: first, from the mode of* catching the disease being possible; and, secondly, from its not giving way to medicines which are of no service in the venereal disease; and this opinion appears to have been confirmed by the disease giving way to mercury. But the case itself, abstracted from the mode of catching it, and even the mode of cure, does not perfectly agree with the common attending circumstances of the venereal; nor has that attention been paid to the necessary circumstances sufficient to determine it to be venereal. ,, , , The progress of the ulceration in the mouth, which was the tnst symptom, was by much too rapid for a venereal ulcer in common : for it must be considered, if venereal, simply as a chancre or local

^Now^t us trace the progress of the disease into the constitution. « About this time,'' viz. when the local disease -as making such rapid progress, "blotches appeared in her face, neck, and various parts of the body : several of these became ulcerated pain- S sores^ Now this date of the constitutional affections following he local is by much too soon to be venereal: we know if a lues venerea arU either from a gonorrhoea or chancre . : does n* appear in common till about six weeks, often much later but.seldom sooner I do not count much upon the circumstance of there being no swellinaof the lymphatic glands of the neck, forming; buboes, as thlt is not a constant symptom attending the ^ed matter getting into the circulation, although it should be}a]lo^li%^ll^

th^re n-t^ & £ pain attending those sores ot in the least c j^^ ^ ^ lues venerea. Venereal b otcnes hara yg y whatever it least very little ; but after all, ™XnTl ^ Pills' were was. Twenty-eight grains ° cal?a^Vor U wasdirected she should taken, probably in ten or twelve day , for rt w ^ butalth U take one or two each day, as the bowels ^^ ag made

tinctura thebaica was glven'™XsP way. But although so little necessary to give no more n i considerably by the bowels mercury was taken, and had also run o ^ d> but yet "the ulceration of her ™uth ana the blotches in her was less painful and of a J^ftffi^ face and body grew pa1^™*"™ Unauenturn cceruleum fortius W=^^^'S^il -bged into ber legs and thighs was therefore directed 332 HUNTER ON THE VENEREAL DISEASE. twice a day, in small doses," lest it should be determined to the bowels. " In about ten or twelve days her griping and purging returned with violence, the ointment was therefore discontinued. At this time the blotches were all gone; the ulceration in her face and body were completely healed, and those of her mouth nearly so."—[Qp. cit., p. 328.] The only remark I have to make on the cure is, that the quantity of mercury was not sufficient to cure chancres on the penis, making such rapid progress as those did in her mouth; nor could the same quantity of mercury cure venereal sores on the skin, which had made such rapid progress as they did in this case; and if we take in the effect this had upon her health, with the termination of the whole, I think we should pronounce it not venereal: for the specific circumstances, if it was venereal, were just as uncommon as the mode of catching it. Many of these cases, suspected of being venereal, I have seen occasionally; and although the patients recovered while under a course of mercury, yet on account of the want of attention in the practitioners to the very circumstances that would decide the disease to be either venereal or not, I pass them over unnoticed. After having considered the cases themselves of those who had the teeth transplanted, let us also consider the persons from whom the teeth were taken; for I cannot help thinking that this will throw some light upon the subject. Let me suppose that the young girls from whom the teeth were taken really had the lues venerea, and that the teeth were of course also infected, which is a supposition most unfavourable to my real opinion, it appears to me that even in this case there can be no difference between the gums of the girl from whom the tooth was taken, and the gums of the person who received it. If the ulceration took place in the last from contamination would not the socket in the girl from whom the tooth was taken likewise have ulcerated ? But this did not happen in any of them. I have here supposed the teeth capable of being contaminated ; although I believe we have never yet seen them have this disease primarily, but only in consequence of its breaking out somewhere else, in the mouth, throat, or nose, and spreading to them. But still, if they are capable of having the disease, and communicating it to others, it becomes very extraordinary that those people should have hit upon the few teeth that probably were ever so contaminated. When we consider that the girls from whom the teeth were taken had not the least appearance of disease at the time, and had none when the disease broke out in the person who received the teeth, it becomes strange that it should break out in the receivers and not in the giver. It is also singular that an ambiguity should follow this disease in all its stages: in the mode of its being caught, the appearance, and the cure. Let us sum up all the arguments in favour of the disease not DISEASES RESEMBLING THE LUES VENEREA. 333

being venereal. First, two patients, whose cases were similar to the others in their origin, recovered without medicine. Secondly, they who seemed to be cured by mercury had not a treatment exactly similar to those who were indisputably poxed. Thirdly, I consider it as impossible for parts to have the power of contaminating which are not themselves diseased. Fourthly, the parts contaminating were never known to have been contaminated themselves. But it must be nearly the same thing to those who want to have teeth transplanted, whether my reasoning is just or not; for a disease in consequence of the operation most certainly has taken place; and in some cases this has been worse, or cured with more difficulty, than the lues venerea in common ; and whatever the disease may be, I yet know of no mode of prevention, except the drawing of the tooth early, and that has been tried in one case only, and in that case was successful. From this account many may be deterred from having this operation performed. In that light no evil can arise, except the mortification which arises from a reflection that no relief is to be had in cases of bad teeth. But it is to be remembered that this is a publication of all the unsuccessful cases, which is the very reverse of what is generally practised in medical books; and they are mentioned upon no other principle than that the disease, when it happens, may not be improperly managed. It may be asked, what is this disease? There is more difficulty in answering what it is than what it is not. I should say that a sound tooth transplanted may occasion such an irritation as shall produce a species of disease which may be followed by the local complaints above mentioned. I cannot conclude without intimating that undescribed diseases, resembling the venereal, are very numerous ; and that what I have said is rather to be considered as hints for others to prosecute this inquiry further, than as a complete account of the subject, THE END. EXPLANATION OF THE PLATES. PLATE I.

Fig. 1. The penis slit open, showing a stricture in the urethra, about two inches from the glans. The stricture is but slight. A A the cut surface of the corpus spongiosum urethrae. B B the canal of the urethra, in which may be observed the orifices of the lacunae. C the stricture. Fig. 2. The penis slit open for about three inches, to show the lacunae, which become occasionally an obstruction to the passage of the bougie. A A the corpus spongiosum urethra. B B the internal surface of the canal of the urethra, pointing to the orifice of two of the lacunae. C a bristle introduced into a lacuna. D the end of the bougie introduced into the remaining part of the urethra.

Fig. 1. The urethra opened in two different places, one before the stricture, the other behind : the one before is through the body of the penis, the other behind is upon the anterior surface of the membranous part; and a bougie passes from the one opening to the other. A A the crura penis and bulbous part of the urethra, all blended together by inflammation and suppuration, which has taken place in many parts. B B the prostate gland in a diseased state. C C the cut edges of the bladder. D the urethra behind the stricture, very much enlarged; irregular on the surface in consequence of ulceration. E E the cut surfaces of the corpora cavernosa penis. F F the cut surfaces of the corpus spongiosum urethrae. G G a bougie passing from the sound to the unsound part of the urethra. H a small bougie in the new passage. Two canulas for applying caustic to strictures in the urethra. Fie 2 A straight silver canula, with the plug projecting beyond the termination°of the canula, making a rounded end ; at the other end of the wire is a small port-crayon, in which is represented a piece of caustic. Fie 3 A flexible canula, for applying caustic to strictures in the bend of the *' ethra. The wire with the small port-crayon, is pushed out beyond its end. . , . Fi 3 A piece of silver wire, with the plug at the end, to be introduced into the canula, as in figure 1. 336 HUNTER ON THE VENEREAL DISEASE. PLATE III.

The bladder and penis of a person who died of a mortification of the bladder in consequence of a stricture and stone in the urethra. In this plate not only the stricture is represented, but the thickened coats and fasciculated inner surface of the bladder; as also the small stone, which acted as a valve or plug; beside which, a canula is introduced from the glans down to the stricture, showing the practicability of destroying it with caustic. A A the bladder, cut open, showing its coats a little thickened, and its inner surface fasciculated. B the body of the penis. C C the corpus spongiosum urethrae cut open through its whole length, exposing the urethra. D the prostate gland divided. E a silver canula introduced into the urethra, through which the caustic is passed on to the stricture. F points out the stricture, with the stone lying above, so as entirely to prevent the passage of the urine.

An enlarged prostate gland, particularly the valvular process, which has increased inwards, into the bladder, in form of a tumour; in consequence of which the water passed with difficulty, which became the cause of the increased thickness of the bladder. A the prostate gland. B the projecting part passing into the cavity of the bladder. C C a bristle in the urethra, to show it is above this tumour. D the cut edge of the bladder, which shows its increased thickness.

A kidney, the ureter, pelvis, and infundibula of which are very considerably enlarged in consequence of a stricture in the urethra. A the substance of the kidney which has become very thin. B B the infundibula much enlarged. C the pelvis very much enlarged. D the ureter increased more than ten times its natural size.

The valvular part of the bladder, so increased as to form a considerable tumour, projecting into the cavity of the bladder. The prostate is also enlarged. This tumour had been the occasion of several severe suppressions of urine, and had often been the cause of a failure in drawing off the water with a catheter, by that instrument, most probably, passing into its substance so deep as to hinder the urine entering its openings. The dark line, passing along the tumour from the urethra, was probably made by this means, but now collapsed. A A the cut surfaces of the prostate gland. B B the inner sides of the prostate gland projecting inwards. C the tumour. D the cavity of the bladder. PLATES HUNTER ON THE VENEREAL DISEASE Fig. 1. PLATE I. Fig. 2. 30 PLATES TO HUNTER ON THE VENEREAL DISEASE. 339 Fig. 1. PLATE IT. Fig. 2. Fig. 3. Fig. 4. PLATES TO HUNTER ON THE VENEREAL DISEASE. 341 PLATE III. 30* 0�75 30 �72727 291313 PLATES TO HUNTER ON THE VENEREAL DISEASE. 343 PLATE IV. 7653 PLATES TO HUNTER ON THE VENEREAL DISEASE. 345 PLATE V. PLATES TO HUNTER ON THE VENEREAL DISEASE. 347 PLATE VT. •V*i.; w J £v-ri '"issfcsJ fev >T'V-'.fl



====================================================================================================
VOLUME III
A Treatise on the Blood, Inflammation, and Gun-shot Wounds (notes by James F. Palmer)
====================================================================================================

^i ft i.i ;1 ARMY MEDICAL LIBRARY

WASHINGTON Founded 1836 ANNEX Section. Number

SENIOR SUBGEON TO THE ST. GEOBGe's AND ST. JAMEs's DISPENSABT, FELLOW OF THE KOYAL MEDICAL AND CHIRUBGICAL SOCIETY OF LONDON, ETC., ETC. '5. -..',/i . ,^, ft VOL. III.

ILLUSTRATED WITH NUMEROUS ENGRAVINGS. THE BLOOD,

INFLAMMATION, AND GUNSHOT WOUNDS;

WITH NOTES BY JAMES F. PALMER.

." LIBRARY "j iSURGEON GENERAL'S OFFICE!

V>3 TREATISE BLOOD, INFLAMMATION GUNSHOT WOUNDS BY JOHN HUNTER, F.R.S. mitix $lotes JAMES F. PALMER, SENIOR SUBGEON TO THE ST. GEORGE'S AND ST. JAMEs's DISPENSARY; FELLOW OF THE ROYAL MEDICAL AND CHIRURGICAL SOCIETY OF LONDON, ETC. i^i&Hi-ux"

"jjibk*-*- iii+iU-t^^v "''.■■•/<»'-» iuRGEON GENERAL'S OFFIC *TUG.-/.6~19(H pfttlaSelptsn-----..... HASWELL, BARRINGTON, AND HASWELL 293 MARKET STREET. NEW ORLEANS: JOHN J. HASWELL & CO.

1841. TO THE KING. MAY IT PLEASE YOUR MAJESTY, L\ the year 1761 I had the honour of being appointed by Your Majesty a Surgeon on the Staff in the expedition against Belleisle.

In the year 1790 Your Majesty honoured me with one of the most important appointments in the medical department of the army, in fulfilling the duties of which every exertion shall be called forth to render me deserving of the trust reposed in me, and not unworthy of Your Majesty's patronage.

■ The first of these appointments gave me extensive opportunities of attending to gunshot wounds, of seeing the errors and defects in that branch of military surgery, and of studying to remove them. It drew my attention to inflammation in general, and enabled me to make observations which have formed the basis of the present Treatise. That office which I now hold has afforded me the means of extending my pursuits, and of laying this work before the public.

As the object of this book is the improvement of surgery in general, and particularly of that branch of it which is peculiarly directed to the service of the army, I am led by my situation, my 4 DEDICATION. duty, and my feelings, to address it, with all humility, to Your Majesty.

That Your Majesty may long live to enjoy the love and esteem of a happy people, is the fervent wish of Your Majesty's Most faithful subject, And most dutiful servant, JOHN HUNTER. Leicester Square, May 20, 1793. PREFACE. The philosophic spirit which pervades every part of the ensuing Treatise, and the profound insight which it discovers of the operations of the animal economy, both in health and disease, have universally procured for it a high rank among medical writings. We should not perhaps greatly err in stating that its distinctive merit consists in the bold enunciation, of the governing laws of life, with reference more especially to the healthy organization, and in the application of those laws to the elucidation of disease. In this respect the Author may justly claim the merit of having- originated a new method of investigation, and of having prosecuted this method in a manner and to an extent which was never contemplated by any previous physiologist, either as regards the comprehensive system of illustration which is adopted, or the masterly exposition of the reciprocative influences of the different organic systems on one another. In the introductory discourse to his Lectures on the Principles of Surgery, the Author distinctly declares this to have been his object; for " By an acquaintance with principles," he observes, " we learn the causes of disease, and without this knowledge a man cannot be a surgeon." Those, therefore, who apply the ordinary rules of a petty criticism to the present work will form a very incorrect judgment of its merits, while those who come to its perusal with the expectation of finding a simple exposition of disease, will probably be much disappointed. The reader who would form a just and accurate appreciation of a work of this character, should bring to the task considerable liberality of mind, and at the same time an independency of judgment, which can admit the general propriety of an observation, and yet know how to make those due and necessary abatements which all general propositions require. 6 PREFACE. The Treatise on the Blood and Inflammation has popularly been considered as Mr. Hunter's chief W ork, and that on which his fame as a Physiologist has principally reposed.. This opinion in some respects is correct, but in others it does great injustice to the Author; for though undoubtedly the work in question contains many profound views of the animal economy, of unrivalled excellence and value, it never can be regarded as the type and consummation of all his previous researches. In order to evince the absurdity of such an opinion, it is only necessary to glance at the extensive series of preparations contained in his museum, and to reflect on the impossibility of embodying the physiological inferences deducible from such a mass of materials in the limited compass of a volume. From the Author's own allusion to the subject, in his paper on Digestion, as well as from the general nature of the preparations which were made, especially the prolegomena attached to the physiological series of preparations, and the numerous highly finished drawings by which these w7ere illustrated, there can be no question that a general treatise on physiology was designed, which, had the Author been spared to complete his plan, would have exhibited in a more just light the originality and comprehensiveness of his mind. To what purpose would he otherwise have bestowed such extraordinary assiduity in compiling ten folio volumes of notes, but that he might, in the decline of his life, complete from that source the great undertaking to which his whole life was devoted ? In treating of the subject of Inflammation, the Author has commenced the inquiry by an investigation into the general properties of the blood, which he proves, by a new train of argument, to be possessed of life, like the solid parts, so as to constitute the chief bond of union by which recently divided parts are united: he next takes a comprehensive survey of the vascular system, and of its functions in health and in disease; and having discussed the subject of union by the first intention, which he considers to be an act essentially different from inflammation, he at leno-th enters on the main subject of his discourse. This he treats in the order of its terminations, and in reference to the various circumstances which have a tendency more or less to modify the local and constitutional phenomena which it presents; and finally he illustrates the whole subject by a PREFACE. 7 series of cases selected from the different organs and structures of the body, and especially by the subject of gunshot wounds. In the course of these inquiries the author is not unfrequently observed to diverge into collateral disquisitions, especially on physiological topics, which bear only in a remote manner on the main subject of his treatise, but which, from the importance of the principles which they involve, or else perhaps from the habit to which his mind had been accustomed of considering the body as a whole, it fell within his original purpose to consider. I shall not here stay to discuss the propriety of such a course on ordinary occasions, or whether such an example is to be held out to imitation to inferior minds; but such a course I am convinced was admirably calculated to call forth the immense treasures of Mr. Hunter's experience, and to cement more firmly that alliance between Pathology and Physiology which forms the characteristic feature of his doctrines. In one respect such a desultory mode of composition must undoubtedly be considered as a defect, from its tendency no less to embarrass the reader than to divert his attention from the main scope of the discourse. It is, however, a defect which the author would probably have himself corrected-, had he lived to superintend his w^ork through the press, and more particularly if his life had been spared to have given to the world a second edition of this great master-piece of his genius. When I first undertook the office of revising and commenting upon Hunter I was less fully impressed than I now am with the difficulty of the undertaking, and I should probably have entirely abandoned the task but for the reflection that no weight would be attached to the opinions of his commentator beyond what was fairly warranted by the force and justness of his arguments. The rule which I have chiefly observed in the insertion of notes has been to correct any impressions, arising from the Author's statements, which the progress of science has rendered doubtful. On such occasions, however, I have invariably given my authorities, or assigned the reasons of my dissent, so that, after all, the reader will be left very much to his own judgment. Sometimes I have been able to confirm Mr. Hunter's conjectures by more satisfactory proof, and occasionally I have thought it expedient to collect into one point his scattered statements respecting par- 8 PREFACE. ticular points of doctrine, so that the reader might, in one view, be able to see all that has been said on the subject. I cannot, however, flatter myself that I have attained either of these objects, and still less that I shall escape altogether the imputation of presumption. Much of the obscurity, so often complained of in the present treatise, is to be ascribed to the peculiar circumstances under which it was given to the world. It was published under circumstances of haste, and at a period of the Author's life when he regarded his state of health as very precarious, and when his faculties, oppressed by repeated illnesses, cannot be considered to have been in their full vigour; in addition to which only a small part of the work was through the press at the time of the Author's death, and therefore it could not receive the full benefit of his corrections, or even of those of his executors, who, in consequence of the numerous professional calls upon their time, were compelled to relinquish the task. Many errors consequently have been allowed to pass unobserved both in the text and punctuation, which often vitiate the sense, and still more frequently render the meaning of the Author extremely difficult of extrication. These have been carefully corrected, and occasionally the correction has been extended still further; but, for the satisfaction, of the reader in such cases, the original text has been subjoined at the foot of the page, or the interpolated passages inclosed within brackets.

JAMES F. PALMER. 38 Golden Square, June 1, 1837.

N.B.—The Editor's Notes are distinguished from the Author's by being placed within brackets. CONTENTS. I. Treatise on the Blood, Inflammation, and Gunshot Wounds.

II. Observations on the Inflammation of the Internal Coats of Veins.

III. On Introsusception.

IV. An Account of Mr. Hunter's Method of performing the Operation for the Cure of Popliteal Aneurism, by Sir Everard Home, Bart., from Materials furnished by Mr. Hunter.

V. Additional Cases to illustrate Mr. Hunter's Method of performing the Operation for the Cure of Popliteal Aneurism, by Sir Everard Home, Bart.

VI. A Case of Paralysis of the Muscles of Deglutition cured by an Artificial Mode of conveying Food and Medicines into the Stomach.

VII. Some Observations on the Loose Cartilages found in Joints, and most commonly met with in that of the Knee, by Sir Everard Home, Bart., from Materials furnished by Mr. Hunter.

VIII. Observations on certain Horny Excrescences of the Human Body, by Sir Everard Home, Bart., from materials furnished by Mr. Hunter. 2 A TREATISE

THE BLOOD, INFLAMMATION,

GUNSHOT WOUNDS. INTRODUCTION.

THE following pages, treating of inflammation, were first arranged in the year 1762, at Belleisle, after the complete reduction of that place. They were compiled from notes and memorandums of observations made in the course of twelve years' residence in London. During this space, my time was occupied in my education under the late Dr. Hunter, and partly in assisting him. In the winter season I was principally employed in the dissecting-room, where I taught the practical part of anatomy ; in the summer I attended the hospitals. The truth of these observations was during the siege of Belleisle in some degree put to the test, by comparing them with many cases of wounds which were attended with inflammation. From the frequency of gunshot wounds at that place, I was naturally led to arrange my thoughts upon the subject, and was induced to select them more particularly for the illustration of my opinions on inflammation. About the year 1770, when I began my lectures on the principles of disease, inflammation was the subject of a considerable part of them ; and from that time till this, though I have been extending and correcting the materials, my principles remain the same. To distinguish the different species of inflammation,*

* In the course of this work I very often make use of the word species or specific, by which I only mean peculiarities or distinctions, and probably the term is much too loose in its application ; for, as we are not entirely acquainted with the specific differences in disease, we may call that a species which more properly ranks as a genus, class, &c. Of morbid poisons we can make a correct arrangement; but with regard to disease arising from peculiarities in the constitution, we have no such absolute guides. 12 HUNTER ON THE BLOOD. and to express my own ideas the better, I was naturally led to stitute such terms as appeared to me more expressive of wnai w meant than those usually employed. The best test of the Pr0P"®iy of these terms is, that they have been adopted by many mecucai writers since that period; and indeed my principles have undergone the same kind of test. In this some medical writers have been very liberal; for, not contented with taking hints, they have even laid hold of large portions of my lectures, screening themselves under the very honourable protection of their not being in print; and, at the same time, quoting authors to show their reading and their candour. It would appear that they consider the discoveries and opinions of a lecturer, found probably in a manuscript, as lair game; though their delicate attention to the rights of another would, no doubt, have prevented them from adopting the same doctrines had they been actually in print. Such freedoms have made me anxious to publish; not only because the public interests itself in the origin of every discovery or opinion, but because I wish to preserve my right, and also to give in a more perfect form what was thought worthy of the public even in a mutilated state. My respect for that public, however, has withheld me hitherto from publishing, that I might first be able to complete my subject, as far as time and other circumstances would allow me. I hope this publication will, at least, have equally good effects with those I have before produced, not only enabling persons to write on the same subject who could not otherwise have done it, but even to become critics in matters of which till then they were entirely ignorant. I have endeavoured, as far as my other pursuits would permit, to form this work into a regular system, one part exactly depending on another. How far I have succeeded, the world must judge. But at the same time it ought to be considered as a new figure composed from rough materials, in which process little or no assistance could be had from any quarter ; wherein the author is conscious of many imperfections, more of which he is persuaded he shall himself observe at every successive review. There are many opinions respecting the animal economy peculiar to myself which are introduced, or frequently referred to, in the course of this work. It is therefore necessary to premise a short explanation of some of them, that the ideas and terms which are employed may be better understood. To others of them, however, this method cannot be applied, as they belong essentially to the body of the work, or are so immediately connected with it as to be best understood when treated in connexion with that part. I shall carry my ideas of life further than has commonly been done. Life I believe to exist in every part of an animal body, and to render it susceptible of impressions which excite action ; there is no part which has not more or less of this principle, and consequently no part which does not act according to the nature of the principle itself, and the impressions thence arising, producing thereby infinite variety, both in all natural and diseased acts. How far every part INTRODUCTION. 13 has an equal quantity of life, or of the powers of life, is not easily ascertained ; but if we were to estimate them by the powers of action, we should judge tolerably well. Disease would seem to give some intelligence with regard to this matter; but how far resistance to disease, and powers of restoration, depend on the powers of life, or simply on the powers of action,* I cannot say; but I believe it may be set down as a rule that those parts that are endowed with most action resist disease most strongly, and in disease restore themselves most readily to a healthy state. § 1. Of diseased Actions, as being incompatible with each other.

As I reckon every operation in the body an action, whether universal or partial, it appears to me beyond a doubt that no two actions can take place in the same constitution, nor in the same part at one and the same time ; the operations of the body are similar in this respect to actions or motions in common matter. It naturally results from this principle that no two different fevers can exist in the same constitution, nor two local diseases in the same part, at the same time. There are many local diseases which have dispositions totally different, but having very similar appearances, have been supposed by some to be one sort of disease, by others to be a different kind, and by others again a compound of two diseases. Thus, the venereal disease, when it attacks the skin, is very similar to those diseases which are vulgarly called scorbutic, and vice versd. These, therefore, are often supposed to be mixed, and to exist in the same part. Thus, we hear of a pocky-scurvy, pocky-itch, rheumatic-gout, &c, &c, which names, according to my principle, imply a union that cannot possibly exist. It has been considered as contradictory to this opinion that a

* [I believe a distinction should be made between resistance to disease and the powers of restoration. The former would seem to be in proportion to the vital energy residing in a part independently of action, as in a fresh-laid egg subjected to cold, whereas the latter would appear to be in proportion to the vital energy conjointly with the powers of action. Action, in the physiological sense of the word, can neither be supposed to exist in an unorganized body nor in an organized body stiffened by cold, although it is well known that living bodies are capable of resisting the effects of a low temperature under both these conditions; that is, the vitaT principle resists by a species of simple antagonism, just as gravity resists force, or chemical attraction electricity, although the former powers may be overcome by the latter when the latter are in greater intensity. In disease also, and especially in epidemical and infectious diseases, the weak and debilitated are most liable to catch the infection, and generally fall the first victims ; so also in poisons, those part3 which are least endowed with life are those which perish most readily. On these occasions, action, it is true, is produced ; but then it is a subsequent, or at the most only a concomitant, effect, intended for the reparation of the injury and absolutely necessary for this purpose. However, it is highly probable that the powers of a part or of the system may be temporarily increased by certain species of fevers and inflammations, which may thus indirectly tend to increase the power of resistance. On the same principle, infection is most effectually resisted by those who are actively engaged in the pursuits of life.] 14 HUNTER ON THE BLOOD. patient might have the scrofula, scurvy, venereal disease, smallpox, &c, at the same time. All of this is indeed possible; but then no two of them can exist in the same part of the body at the same time; but before one of them can occupy the place of another, that other must be first destroyed, or it may be superseded for a time, and may afterwards return. When a constitution is susceptible of any one disease, this does not hinder it from being also susceptible of others. I can conceive it possible that a man may be very susceptible of every disease incident to the human body, although it is not probable; for I should believe that one susceptibility is in some degree incompatible with another, in a manner similar to the incompatibility between different actions, though not of so strict a kind. A man may have the lues and the small-pox at the same time; that is, parts of his body may be contaminated by the venereal poison, the small-pox may at the same time take place, and both diseases may appear together, but still not in the same part. In two eruptive diseases, where both are necessarily the consequence of fever, and where both naturally appear after the fever nearly at the same distance of time, it would be impossible for the two to have their respective eruptions, even in different parts, because it is impossible that the two preceding fevers should be coexistent. . From this principle I think I may fairly put the following queries: Do not the failure of inoculation, and the power of resisting many infections, arise from the existence of some other disease at that time in the body, which is therefore incapable of another action ? Does not the great difference in the time, from the application of the cause to the appearance of the disease, in many cases depend upon the same principle? For instance, a person is inoculated, and the puncture does not inflame for fourteen days, cases of which I have seen. Is not this deviation from the natural progress of the disease to be attributed to another disease in the constitution at the time of inoculation ? Does not the cure of some diseases depend upon the same principle '.—as,,e. g., the suspension or cure of a gonorrhoea by a fever. Let me illustrate this principle still further by one of manv cases firhm\TS£TiUnder\my°wn observation. On Thursday, the ^e^tT^lm°C^ & Sentleman's cJ^,and it was obnT viz ?he i^h ,r 7 ,a^ PUncutures' O" the Sunday follow-

K^t eTe^appeX6 SZ"? £" ^"^ 5 a small tumour. On the 20th ^W^^^.^ I declared that it was not the variolous fever „q t\l -le'ensh ' ?ut had not at all advanced since the 19th. On the 22d^T"

^r^^*^^ ^e ^sles^dt On the 23d he wa^er^^^ INTRODUCTION. 15 on the arms were in the same state as on the preceding day. On the 25th the measles began to disappear. On the 26th and 27th the punctures began again to look a little red. On the 29th the inflammation increased, and there was a little matter formed. On the 30th he was seized with fever. The small-pox appeared at the regular time, went through its usual course, and terminated favourably.*

§ 2. Of Parts susceptible of particular Diseases.

There are some parts much more susceptible of specific diseases than others. Poisons take their different seats in the body as if they were allotted to them. Thus, the skin is attacked by what are vulgarly called scorbutic eruptions, as well as many other diseases : it is also the seat of the small-pox and the measles : the throat is the seat of action in the hydrophobia and in the hooping-cough. The absorbent system, especially the glands, are more susceptible of scrofula than most other parts of the body. The breasts, testicles, and the conglomerate glands, are most commonly the seat of cancer. The skin, throat, and nose, are more readily affected by the lues venerea than the bones and periosteum, which however suffer sooner than many other parts, particularly the vital parts, which perhaps are not at all susceptible of this disease. These differences may arise from the nature of the parts themselves, or from some regular circumstances, which must act as a preexisting cause.

* [In our ignorance of the essential nature of diseases, the principle which is here laid down may be considered perhaps as too absolutely expressed. Tiie disposition and appearances of specific diseases are unquestionably greatly modified by the existence of peculiar states of the constitution at the time, as of scrofula, gout, rheumatism, &c, and this in so striking a manner as to render the distinction between a modified and a conjoint disease almost invisible. Thus, the affections which result from the abuse of mercury on a constitution affected with syphilis are sui generis, and cannot be produced by either of these poisons acting separately. Thus, also, the phenomena of small-pox and cow-pox present many peculiarities which are scarcely reconcileable upon the doctrines laid down by our author. Dr. Willan, for example, found " that when a person was inoculated with vaccine and variolous matter about the same time, (that is, not exceeding a week,) both inoculations proved effective, for the vaccine vesicle proceeded to its acme in its usual number of days, and the maturation of the variolous pustule was attended by a variolous eruption on the skin." (On Vac. cine Inoculation, p. 1.) Dr. Woodville also has said, " that if the cow-pox matter and the small-pox matter be both inserted in the arm of a patient, even within an inch of each other, so that on the ninth day the same efflorescence becomes common to both the local affections, nevertheless inoculating from the cow-pox tumour the genuine vaccine disease will be produced" (Observations on the Cow-pox, p. 12) ; but if the inoculation be performed with a mixture of the two matters, then the chance is equal that small-pox or cow-pox will be the result, or the varioloid disease, either one of which is capable of conferring an immunity on the patient so affected. Here, therefore, are two diseases acknowledged to be distinct and constitutional, not only coexistent in the system at the same time, but (from the blending of the areolar inflammations) apparently in the same part. These phenomena are probably as uncommon in disease as the hybridous productions of the animal and vegetable world in reference to the usual course of generation. Of the latter there is no question, and I do not perceive any antecedent presumption against the occurrence of the former.] 16 HUNTER ON THE BLOOD. § 3. Of Sympathy.

It is unnecessary to give a definition of sympathy, for it is generally very well understood when applied to the mind, and also by medical men when applied to the body. In the mind its reference is external; it depends upon the state of others, and one of its chief uses is to excite an active interest in favour of the distressed, the mind of the spectators taking on nearly the same action with that of the sufferers, and disposing them to give relief or consolation: it is therefore one of the first of the social feelings, and by many useful operations inclines mankind to union. In the body, sympathy has only a reference internally to the body itself, and is not so evident as the sympathy of the mind, although in some cases we see its effects. It is either natural or diseased ; but it is the diseased only that I propose at present to consider. I shall divide the sympathy of the body into two kinds, universal and partial. By the universal sympathy is meant where the whole constitution sympathizes with some sensation or action of a part. By partial sympathy is meant where one or more distinct parts sympathize with some local sensation or action. The universal sympathies are various in different diseases ; but those which arise in consequence of local violence are principally three, viz., the symptomatic, the nervous, and the hectic fever. The symptomatic fever is an immediate effect of some local injury, and therefore is a universal sympathy arising from a local cause ; the nervous has no determined form nor stages of the disease from the first cause, as delirium, spasm, almost of all kinds and in all parts, locked-jaw, &c. The hectic fever is also a universal sympathy, attended with a local disease which the constitution is not able to overcome. Most of these will be more fully treated of when I have occasion to describe their causes. I divide partial sympathy into three kinds; the remote, the contiguous, and the continuous. The remote sympathy is where there appears no visible connexion of parts that can account for such effects. In these cases there is commonly a sensation in the sympathizer which appears to be delusive, and produces a wrong reference of the mind to the seat of the disease, such as the pain of the shoulder in an inflammation of the liver. The contiguous sympathy is that which appears to have no other connexion than arises from the contact of separate parts. An instance of which we have in contained parts sympathizing with the containing; such as the stomach and intestines sympathizing with the integuments of the abdomen, the lungs with the chest, the brain with the scalp, and the testicles with the scrotum. The continuous sympathy is where there is no interruption of parts, and the sympathy runs or is continued along from the irritating point as from a centre, so as to be gradually lost in the sur INTRODUCTION. 17 rounding parts in proportion to the distance; and this is the most common of all the sympathies. An example of it we have in the spreading of inflammation, which will be often mentioned in this treatise.*

Mortification is of two kinds, the one without inflammation, and the other preceded by it. But as the cases of mortification which will be mentioned in this work are all of the second kind, I shall confine my observations to that species. I consider inflammation as an increased action of that power which a part naturally possesses ; and in healthy inflammations, at least, it is probably attended with an increase of power; but in inflammations which terminate in mortification there is no increase of power,f but on the contrary a diminution of it. This, when joined to an increased action, becomes a cause of mortification, by destroying the balance which ought to subsist between the power and action of every part. There are, besides, cases of mortification preceded by inflammation, which do not arise wholly from that as a cause, but rather seem to have something in their nature; of this kind is the carbuncle, and the slough formed in the smallpox pustule. If this account of mortifications arising from no specific nature be just, we shall find it no difficult matter to establish a rational mode of cure ; but before we attempt this, let us take a view of the treatment which has been hitherto recommended, and see how far it agrees with our theory. It is plain, from the common practice, that the weakness has been attended to; but it is plain that the increased action has been overlooked: and therefore the whole aim has been to increase the action in order to remove the weakness. The Peruvian bark, confectio cardiaca, serpentaria, &c, have been given in large quantities, as the case appeared to require, or the constitution could bear, by which means an artificial or temporary appearance of strength has been produced, while it was only an increased action. Cordials and wine, upon the principle

* [See the chapter on Sympathy in the Principles of Surgery, p. 105, for a more complete exposition of Mr. Hunter's views on this subject. It is doubtless in many cases possible to trace the sympathy to a particular distribution of the nerves, as when, for example, the nerves of the affected and sympathizing parts derive their origin from the same parts of the nervous centre. Thus, pain in the back is occasioned by irritation of the pelvic viscera, and hemicrania from caries of the teeth. A perfect knowledge of the minute anatomy of the brain, and of the functions of its different parts, would probably unfold the whole mystery of this subject.] f [By "power," I apprehend, is here signified the resistance which is offered by a living part to disorganization and death. By the expression, " the powers of a purt," is generally meant the sum of the vital actions going on in that part, as circulation, growth, secretion, &c. Mr. Hunter employs the expression in a less complex sense, so as simply to express by it the degree and prevalence of the vital principle.] 18 HUNTER ON THE BLOOD.

on which they have been given, are rationally administered ;^but there are strong reasons for not recommending them, an S the general effect which they possess of increasing tne actio without giving real strength. The powers of the body are oy inib treatment sunk afterwards in the same proportion *s™?y™*°°?* raised, by which nothing can be gained, but a great deal maybe lost; forf in all cases, if the powers are allowed to sink below a certain point, they are irrecoverable. 4-™0i The local treatment has been as absurd as the constitutional. Scarifications have been made down to the living parts, that stimulating and antiseptic medicines might be applied to them, as turpentines, the warmer balsams, and sometimes the essential oils. Warm fomentations have been also applied, as being congenial to life; but warmth always increases action, and therefore should be well adjusted to the case: on the other hand, cold debilitates or lessens powers when carried too far, but at first lessens action. Stimulants likewise are improper where the actions are already too violent. • • 1 Upon the principles here laid down, the bark is the principal medicine as yet known that we depend upon, as it increases the powers and lessons the degree of action. Upon many occasions opium will be of singular service by lessening the action, although it does not give real strength. I have seen good effects from it, both when given internally in large doses, and when applied to the part. It is proper also to keep the parts cool, and all the applications should be cold.*

* [Notwithstanding the condemnation which is here pronounced on scarifications and warm dressings, yet experience and theory both tend to confirm the utility of this mode of treatment. The former, or scarifications, afford an exit to putrid matters, while the latter by their antiseptic qualities diminish the quantity which is produced, and at the same time modify its virulence. But it is not merely the constitutional effects which are lessened by these means. There cannot be the slightest question that the local effects are equally mitigated, and the pernicious consequences of sloughs and ill-conditioned pus in contact with the living textures materially lessened, by providing a free escape for these matters. This subject will be adverted to more fully when speaking of "diffuse cellular inflammation," in which the bad effects of putrid secretions in contact with the living solids are most conspicuously shown. In regard to the advantages of bark, I need not here observe that its pretensions in the present day as a medicine in cases of mortification are rated much more moderately than they were formerly. Practitioners no longer think that strength is imparted to the system in proportion to the quantity of bark which the patient is made to swallow.] GENERAL PRINCIPLES OF THE BLOOD. 19 PART I. CHAPTER I.

GENERAL PRINCIPLES OF THE BLOOD.

As the blood is allowed by all to have a considerable share in inflammation, or at least to be particularly affected by it, becoming, by its appearances, one of the signs or symptoms of its existence, and as the blood is a material object with me in the theory of inflammation, I shall begin my treatise with its natural history, a previous knowledge of which is the more requisite, because the accounts of this fluid hitherto given will hardly explain any of its uses in the machine in health, or of its changes in disease. The heart and vessels 'are very active in inflammations; and as their structures and actions have not hitherto been understood, I have subjoined to the natural history of the blood an account of the structure of the heart and vessels, together with their actions in the machine: to which I have added one use of the absorbents not hitherto known. As every natural action of the body depends, for its perfection, on a number of circumstances, we are led to conclude, that all the various combining actions are established while the body is in health, and well disposed; but this does not take place in diseased actions, for disease, on the contrary, consists in the want of this very combination ; and diseased actions, therefore, vary according to many natural circumstances, of which I propose to point out a few of the most striking instances. Inflammation must have some exciting cause, and the same cause will produce an effect under one circumstance which it will not under another. I have therefore begun with the supposition of an injury, attended with such circumstances as do not excite inflammation, which will form a strong contrast to those which do, the opposite effects mutually illustrating each other; but as inflammation is a very general action of the vessels in disease, and is of various kinds, I have previously given a short account of several of the most common sorts of inflammation, which will explain the rest. The whole material world has been very properly divided into solids and fluids, these being the only essentially different states of matter we are able to observe. From one of these states to the other matter appears to be continually passing, but with these restrictions, that no species of matter can assume a solid form without having first been in a fluid state, nor can any change take place in 20 HUNTER ON THE BLOOD. a solid till it be first formed into or suspended in a fluid.* The living animal body is obedient to these general laws, for all solid and animal matter has first been fluid, and having passed into this solid form, becomes a recipient for other fluids, out of which the solids may themselves be renovated and increased. The solids of an animal, although composed of one species of matter, yet admit of great variety in their appearance ; and this variety takes place in some animals more than in others. But the fluid part of an animal body, in its natural state, has but one appearance, which is that of blood. There are certain parts of animals which, though hardly solid in their own nature, are yet to be considered as solids, from their being fixed in their situation, and appropriated to local actions; some of them acting on the fluids (which are, to a certain degree, passive in all animals), and disposing of them for particular purposes in the animal economy, in the same manner as is done by those which are usually called the solids in animals ; of this sort are the gelatinous parts in many of the inferior orders of sea-animals, as the medusa, the vitreous humor of the eye, &c. There appears to be a sympathetic intercourse between the solid and fluid parts of an animal, designed by nature for their mutual support. In disease, when the machine cannot be furnished in the common way, the solids of the bodv supply the defects, and the person becomes lean;f and the fluids

* [See Principles of Surgery, p. 10. Chemistry affords a few exceptions to the universality of this law. Thus, chlorate of potash combines with sulphur or charcoal by mere attrition; and the greater number of fulminating powders are examples of the same kind. Crystals of Glauber's salt and nitrate of bismuth are converted into a fluid by being rubbed together in a mortar, and so are the solid amalgams of bismuth and lead. The former part of this sentence is manifestly a pleonasm.] f [Without wishing to question the soundness of this opinion, I would yet venture to suggest that it is contrary to analogy to suppose that the body can subsist on its own materials, unless these have undergone a previous digestion. ine (attest people, on this principle, would be the fittest subjects for fevers; repeated losses of blood would produce the greatest degrees of emaciation, and those who have most fat would be the best able to endure privations of food ; all which is contradicted by observation. I apprehend that fatness and leanness depend on a want of balance between the waste and supply, the waste being prinrn\P«flL0CCaSTld.uy 3n acceleration of ^e vascular actions, and the morf rapid interchange which thence ensues in the molecular particles of the body. This is S ■ ThPlUTim yTg and, Srowine animaV and in birds, as contrasted with amphibia, adults and animals of the tardigrade species. The former require a.continual supply of food to replace the effete matter, while theSe are enabled to sustain hunger for a long time without injury. Ths hvbe rnatin* arnmals retain their fatness during the whole period of theiTorpiditJ D? Stevens mentions having seen a rattlesnake a<? fat »ftor „;„ lorpiaity. ur.

time that ?hwasteLm I'J^Z \" ^ -the SUppl* is cut off at *e same active minds and bodTe? areseZ 1™ * ,lncreased- Thus, also, persons of during the period o' utero^s ,o«tj7* /V^ ^ W°men «™ *in The uses of fat probablv are ,n nV lmalS dur,nS the Period of ^ rut. GENERAL PRINCIPLES OF THE BLOOD. 21 would appear from this to be more an object of attention in the machine than even the solids. This fluid part of an animal is called the blood, and in the animals with which we are most acquainted it is of a red colour. The nature and appearances of the blood have been more attended to in diseases, especially of the inflammatory kind, than in full health, as it is more expressive of disease when removed from the body than any of the solids, and undergoes changes which the solids do not. Some of these changes are produced by the separation of parts from one another; but as the body is seldom in perfect health, we can hardly procure the blood in the same state twice from one person, although it may not be sensibly diseased. In a history of the blood these varieties must be mentioned, although they are often slighter appearances of what we find in disease; for diseases certainly throws great light on the natural history of the blood, and the apparent changes which it undergoes must have unavoidably called medical men to consider it with attention. The only knowledge, however, we have of any difference in the blood, arises from these varieties in its spontaneous changes when extravasated;* nor do these differences appear always to affect the real nature of the blood, as the animals often continue in health while they are going on. Blood is most probably as much alike in all animals as the muscle of one animal is like that of another, only with this difference, that some animals have not that part which gives it the red colour; but the other parts, as the lymph and serum, are, as far as I yet know, the same in all.f

* [The progress of modern chemistry has not only enabled the pathologist to detect many diseased states of the blood which were perfectly unknown in the time of Hunter (see note, in Principles of Surgery, p. 136), but has enabled the physiologist also to pursue his investigations on entirely a new tack, from which the greatest acquisitions to science may be expected to accrue. In order, however, that the alliance of chemistry with physiology may be really rendered useful, it is important to bear in mind that the object of the chemico-physiologist should be not so much to discover the modes in which the vital principle operates, as the results which those operations give rise to, so as to be able to trace their dependence on one another, or the relation in which they stand, as cause and effect. This can only be done by the most scrupulous and exact analyses of the animal fluids, and particularly of the blood, as the point de depart from whence all the others proceed. Hunter did not altogether reject these aids, although, from the state of organic chemistry at the time that this treatise was written, he was little disposed to place reliance on the results which it afforded.] t [Berzelius has verified this observation, as far as regards the serum and fibrin in the higher orders of animals, but the globules are found to vary very considerably in size, shape, number, and composition in the different species. The same authority has also stated that there are two-thirds less of the muriates in ox blood than in that from the human subject, but a larger proportion of nitrogen. (Med. Chir. Trans., vol. iii.) This latter fact would, indeed, be very remarkable if true, considering that man lives for the most part on a highly azotized food, whereas the ox lives on food which contains no nitrogen at all. The recent researches, however, of Macaire and Marcet (Mem. de la Soc. dePhy. et (PHist. Nat. de Geneve, v. 389), have not only shown the error of this particular fact, but, as far as concerns the ultimate analysis of the blood, have established 3 22 HUNTER ON THE BLOOD. Transfusion of the blood of one animal into the vessels of another proves, to a certain degree, the uniform nature of the blood, for, as far as these experiments have been urged, no alteration has been observed.*

the almost entire identity between that of herbivorous and that of carnivorous animals. Certain minor differences in colour, in the relative proportions of crassamentum and serum, in the halitus which exhales from fresh drawn blood, and in the period of coagulation, have been pointed out by Thackrah ; but these are not greater than what may occur in the blood of the same individual taken from two different vessels, or at two different periods of life. (Inquiry into the Nature and Properties of the Blood, by C. T. Thackrah, 2d Edit. p. 149.)] * [The honour of this discovery has been sharply contested between the French and English. From certain passages in the classics it seems highly probable that the practice was not unknown to the ancients ; at any rate the operation was described by Libavius at least fifty years before the English and French controversy commenced. (In Def. Synt. Arc. Chy. contra H. Schneumannam, Act. 2, p. 8. Edit. Francof. a. 1615.) The operation of transfusion was first performed on the human subject in France, by MM. Denis and Emmerets, on the 15th of Junp, 1667, and repeated in England by Drs. Lower and King on the 23d of November of the same year. It speedily grew into great favour; but in consequence of the fatal and dangerous effects which ensued in several cases, it was interdicted by a sentence of the Chastelet, and soon afterwards fell into desuetude. The blood of calves and sheep was generally employed in these operations, and, so far as appears, the blood of the human subject was never thought of. In 1785 Dr. Harwood revived the inquiry, by making it the subject of his inaugural thesis, which he supported by many interesting experiments on dogs, which he performed in public. (Phil. Trans. Abr., vol. i., p. 185, note.) MM. Prevostand Dumas, Dr. Leacock, and finally Dr. Blundell, followed in the same track. It was ascertained by Dr. Harwood, that when an animal was bled to complete syncope, it was capable of being resuscitated, by the transfusion of fresh drawn blood from another animal of the same or a different species ; although when the latter was employed, the animal generally perished before the sixth°day. MM. Prevost and Dumas ascertained, that although the respiration remained calm, the pulse became remarkably accelerated, the heat of the body was rapidly dissipated, and the dejections and urine became mucous and bloody, and continued so in many instances until death. They found also, that when blood containing spherical globules was injected into a bird, it died, as if poisoned, with violent symptoms of distress of the nervous system, which effects uniformly occurred, whether the precaution of bleeding the animal beforehand had been previously resorted to or not. Sheep's blood restored cats and rabbits for a few days from the exhaustion consequent on excessive hemorrhage ; but it excited rapid and violent convulsions, followed by speedy death, when it was injected into ducks. These experiments, therefore, sufficiently demonstrated the danger attending the translusion of large quantities of blood from an animal of one species into another animal of a different species. Smaller quantities, indeed, were proved not to be dangerous to life, although unpleasant effects generally followed. Thus, Mr. txoodndge,of Barbadoes, has lately injected human blood into the veins of a dog, and the animal afterwards survived. att?nH-B1U?^e11't0 wh.om lhe Profession is indebted for every practical advantage ^v^V^9^10^-^0117 repeated the exPe'im™ts above-mentioned blood hi L ? i if ?eifo™Ing thB Tm,10n °" the human subJect- With human Succeeded in '^f * M]T°V ^J™ three W6eks "* this means alone' and full five minu es T^ T^ by S,m'lar "T"* after U had ceased *> respire for , "ve mlnutes. In order to nrnvn that tl,*> ,.™.o,.. „<• .u_ li . ■.. '* substances does not d he connected, by mear GENERAL PRINCIPLES OF THE BLOOD. 23 Concerning natural objects, we usually acquire a gross knowledge, from the frequency with which they are observed, and it often requires little more than common attention to have a tolerable conception of their general principles. This is the case with the blood. Blood is known to be of a red colour in a great number of animals, and to be altogether a fluid while circulating in the living body. It is known to separate into parts when out of the body, and a portion of it to become solid,; it is likewise known, that when deprived of a certain proportion of it, an animal dies; it has, therefore, been held in particular veneration, as constituting the life of the animal. Like other things which are discovered to be of great use, the blood has frequently attracted the attention of mankind as an object of curiosity only, from which some have proceeded to a more critical inquiry into its nature and properties, and to a more extensive elucidation of the subject at large. To this practitioners in physic have a great deal contributed, from a conviction that this knowledge would be of much use to them in their profession ; and the teachers of the art have been still more industrious in their investigations ; but the frequent recourse which is had to the lancet in diseases has afforded the most ample opportunities of observation, almost sufficient to explain every principle in the blood without the aid of further experiment. In animals possessed of red blood, two modes of investigation may be adopted. One of these respects the blood while it is circulating, when the colour makes its motion visible, and gives an idea of the circulation in the smaller vessels. Accidents, operations, and anatomical knowledge of the vessels in which the blood is contained, have at the same time assisted us to form more perfect ideas of its motion in the larger vessels. The other mode, which is that of examining the blood when out of the body, enables us to observe whatever relates to its spontaneous changes and separation, together with the apparent properties of each component part. Its chemical properties become known likewise by this second mode, though without throwing much light on the nature of the fluid itself. The blood is called a fluid because it is always found in a fluid state in the vessels of a living animal while under the influence of the circulation; yet it is not, under all circumstances, naturally so, same animal, and continued to impel the blood from the artery into the vein for twenty or thirty minutes, until the whole blood of the animal must have passed through the apparatus. (Med. Chir. Trans., ix. 56, and x. 296.) In order that the operation may be successfully performed, it is necessary to be exceedingly careful to exclude the ingress of air or clots of blood, and to proceed in so gradual a manner as not to endanger a sudden plethora. With these cautions, transfusion may be regarded as a valuable auxiliary means in the hands of the surgeon, particularly in the treatment of flooding or alarming hemorrhages from other causes. I may mention that it has succeeded in several cases of this kind where little or no hope could have been entertained from any other resources. It is unnecessary to add, that the blood should always be taken from a healthy human subject, and be allowed to stagnate in the apparatus as little as possible.] 24 HUNTER ON THE BLOOD. for of one part of it, when not circulating, solidity is a necessary and essential property, fluidity being only necessary at the time of circulation for its motion, distribution, and the easy separation of its parts. Without being fluid, it could not be propelled through flexible tubes, and distributed to all parts of the body. It could not be divided into portions, as the vessels branch off; it could not pass through the smaller vessels, nor admit of the various separations of its parts, which are to produce the increase and repairs of the whole body; neither could it be adopted for furnishing the various secretions; nor could it be brought back to the heart.* The red colour of the blood is produced merely by some red matter diffused through it, but not common to all animals. The blood exhibits a greater variety of changes, and admits of more experiments to determine its nature and properties, than the solids. This, in some degree, arises from its fludity, in which form it has not yet attained its ultimate state, and is only the substance that furnishes materials out of which the solids are produced or augmented. & The heat in the animal body, principally in those which are called warm animals, has been commonly considered as depending principally on the blood, or at least as being connected with it as much as with any other portion of the body.f As I shall have occasion to take notice of the increased heat of inflamed parts, it might be expected that I should endeavour to explain this principle in the history of the blood. I profess, however, not thoroughly to understand it, and the theories hitherto brought forward do not in the least satisfy me, as I think that none of them accord perfectly with every circumstance observable in these cases.

§ 1. Of the Mass of Blood, as composed of different Parts.

The blood, while circulating in the vessels, appears to the eye to be a homogeneous mass; but when it is passing in vessels so small as almost to separate its visible parts, and is viewed in a microvessels. G 1S n° apPearance but that of g^bules moving in the

In such a situation the other parts, called the coao-ulable lvmoh

tTanptemTndXnTHd;Stin§Uishable' °n ™< ?f their Cn'g transparent, and the globules do not, strictly speaking, constitute!

* The distribution of water from the spa i<s eimU*. ♦„ *u the rivers returning to it have anl oVv „ h ' u *l^ SyStem' and ferent, because the^ globe works entire^7. nn„ it 8' bUt their effecfs are dif' are continually carrying away thHand11° „ ??" •materials- The waters another, taking dow'n contSts InXv " the^cea"!0^"' f'*™^ in the ..n,e t,me they are raising continents ouf of'h sea flit Inf'f? W^St * t Sm wtVce^0^ ^^ '° '^ ^*^U«• ^ *^^rt*^g-£$2£$« ^-blooded animals; but spheres, and animals of a ^l^Zte^Z^S ^ fa M ^ GENERAL PRINCIPLES OF THE BLOOD. 25 part of the fluid, but are only diffused through it. These globules being red, give this colour to the blood, and are called the red part, but are not always of the same redness when collected in a mass; this is probably owing to each globule being changed in its tint of colouring. The blood of some animals has no such globules, but is perfectly transparent, indeed more so than the most transparent parts of the red blood, to which it is analogous. A red colour is therefore not essential to constitute true blood; and I believe the slight tinge of colour there is in the blood, independent of the globules, arises from the solution of various substances in the serum. The blood has a peculiar taste, being saltish, but of a peculiar flavour:* we can always distinguish by the taste when there is blood in the mouth. These are the principal observations we can make on the blood when circulating, or in its fluid state; but as one part of it under certain circumstances changes into a solid, or, as it is commonly termed, coagulates, more of its parts are thus exposed; in this process the blood separates into two distinct substances, a coagulating part, and another which separates from it and remains fluid; but the coagulum entangles the red part, and this alone shows the blood to be formed of these component parts. The parts of the blood so separated have been named according to their apparent properties ; the one, the coagulable lymph ; the other, the serum ; and the red part has been called the red globules; but upon a more intimate knowledge of the different parts of this fluid, we shall find that those terms are not expressive of all their properties. The term coagulable lymphf is not expressive of this property, as one which is inherent in the lymph itself, for many substances are capable of being coagulated, though not spontaneously, yet by chemical means. For instance, heat coagulates the farinaceous part of vegetables, and thus forms paste, and also mucus. Spirits of wine coagulates many animal substances; acid coagulates milk, &c.; the term, therefore, to be used respecting this property of the blood should be such as expresses its inherent power of self-coagulation: perhaps coagulating might be better applied to what is called coagulable lymph, and the epithet coagulable might be reserved for those fluids which require a chemical process to produce that effect. Of this kind is the serum, for 1 have discovered this fluid to be composed of two parts, which is ascertained by means of the different causes of coagulation. To discover all the various properties and

* [It is also slightly nauseous and alkaline. Turmeric paper is rendered blown, and syrup of violets green, by the very first drops of serum which exude from the clot.] f [Gluten, fibre of the blood, and fibrin, are terms which have also been applied to this principle of the blood. The latter term is now most frequently adopted, from its being in some degree expressive of the fibrous or half-organized texture which this substance exhibits when the serum is expressed from it. The whole coagulum, consisting of the above-named substance, interposed serum, and red globules, has been variously designated by different writers, as cruor, hepar sanguineum, placenta, insula, gluten, riot, and crassamentum,] 3* 26 HUNTER ON THE BLOOD. uses of the component parts of the blood in the machine may be impossible ; and to determine whether they will act, or are employed conjunctively to produce the effect, is not easy; but there are some properties discoverable which would incline us to believe that particular parts of the blood are employed to compose particular solid parts, which are found to possess properties similar to different parts of the blood.* § 2. Of Coagulation, and its Effects.

As coagulation is the first change which the blood undergoes when out of the vessels, and as it even coagulates while in them, under certain circumstances, we shall consider this process first. Though fluidity is necessary to enable the blood to circulate, yet * [The probability of the opinion expressed in the text will be adverted to in a future part of the work. In the present note I propose briefly to point out the principal results which have been obtained by modern chemistry, as regards the composition of the blood. s

_____________Analysis of healthy serum by M. Le Canu. Water ......... Albumen...... Organic matters soluble in water and alcohol* \ Albumen combined with soda .... Oleaginous matters \?}1? matter ••••''.! „ . ,. „ C ^rystalhzable fatty matter . . Hydrochlorate of soda and potash . . oTas1!!011^ and phosphate of soda> and* sulphate of Phosphate of lime, magnesia and iron, with subcarbon- ) ate ot lime and magnesia.........> Loss . . . 1st Analysis 906-00 78-00 1-69 2-10 1-00 1-20 600

1-00 1000-00 Analysis of serum by Berzelius and Marcet. Water...... Albumen . . . . ........ Hydrochlorate of soda and potash'

1000-00 GENERAL PRINCIPLES OF THE BLOOD. 27 coagulation is no less necessary, when it is to be disposed of out of the circulation, even within the body, and therefore deserves to be Analysis of healthy venous blood by M. Le Canu. Crassamentumdeprived ? Colouring-matter. 1st Analysis. 2d Analysis. Average. 133000 119-626 126313 of water and salts . s Fibrin .... 2-100 3-565 2 833 f 780-145 785-590 782-868 65-090 1-310 69-415 2-270 67-252 1-790 matters \ Crystallizable fatty matter 2-430 4-300 3-365 g Extractive matters soluble in alcohol > 1-790 1-920 1-855 H Albumen combined with soda . . . 1-265 2010 1-637 9J 72 Chloruret of sodium and potassium, subO carbonate and phosphate of soda, and > 8-370 7-304 7-837 Phosphate of lime, magnesia and iron,") | peroxide of iron, and subcarbonate of £> 2-100 1-414 1-757 l^ lime and magnesia . . • . . J 2-400 2586 2-493 1000-000 1000000 1000000 (Journ. de Pharmacie for Sept. and Oct. 1831. Med.-Chir. Trans., iii. 230.) The great correspondence of the preceding analyses in all main particulars is a great voucher for their accuracy. I shall only therefore further remark that the mucoextractive matter of Marcetis probably the impure " lactate of soda and extractive matters soluble in alcohol" of Berzelius, the osmazome of Thenard and Denis, and the oleaginous and extractive matters of Le Canu. Likewise also the oleaginous matters of Le Canu, which were first fully investigated by Traill, Christison, and Babington, answer to the " graisse phosphuree rouge et blanche" of Vauquelin and Denis and the " matiere cerebraie rouge et blanche" of Chevreul. Berzelius is of opinion that the earthy phosphates, the sulphate of potash, and several other substances, are formed during combustion, or by the process of analysis, and do not exist originally in the blood. (Op.cit., pp. 227, 233.) We may therefore regard the blood in three lights : 1st, as flowing in the vessels, when we should say that it consists of two substances, the liquor sanguinis and red globules; 2d, as extravasated from the body, when we should say that it is composed of crassamentum and serum ; and 3d, in its chemical relations, when we should say that it is made up of three parts, essentially differing from each other, viz., water, saline, or adventitious substances, and nutritive matters ; the latter, in consequence of their close chemical correspondence, being now generally regarded as modifications of albumen. According to some chemists, the blood also contains carbon (Ctanny) ; carbonic acid (Vogel, Brande, &c.) ; acetic acid (Hermann) ; cruorine, cholesterine, and osmazome (Denis); seroline (Boudet) ; a yellow colouring matter (Lassaigne, Chevreul) ; a peculiar aromatic principle (Burrueil) ; globuline, one of the constituents of the globules, consisting of a modification of albumen and a peculiar colouring matter (Le Canu); a substance analogous to urea (Raspail, Segalas) ; copper (Meisner, Sarzeau) ; soda, either free or in the state of carbonate (nearly all chemists) ; sulphur (Vogel) ; and minute traces of silica, alumina, and manganese (Turner and O'Shaughnessy). As the presence, however, of these substances in healthy blood has either been disputed or denied by the generality of chemists, it would be improper to include them among the regular constituents of this fluid. The process employed by Le Canu for obtaining the quantitative results contained in the preceding analyses, 1 shall transcribe in his own words: "I evaporated," he says, " a determinate quantity of healthy serum at a gentle 2-S HUNTER ON THE BLOOD. considered with no less attention. There is, I think, more to be learned of the use of blood in the animal economy from its coaguheat, and the loss which it sustained gave me the weight of water. Then heating the residue, first with boiling water and afterwards with boiling alcohol, the former dissolved out the soluble salts and extractive matters, and the latter the tatty matters. The aqueous solution being now filtered and evaporated in a sandbath, and the residue treated with alcohol at 40°, until it ceased to be further coloured, I by this means separated the extractive matters soluble in alcohol. Ihe residue, consisting of salts mixed with extractive matters, insoluble in this menstruum, was calcined, to know the proportion of organic matters, and the new residue treated with boiling alcohol, to separate the hydrochlorates. " The fatty matters which were taken up by the boiling alcohol were further separated by means of alcohol at 33°, which when cold does not dissolve the crystalhzable matter; finally, the albumen, thus deprived of all its soluble contents, was dried, weighed, and afterwards calcined. A very small portion of soluble salts, contained in the residue after incineration, was separated bymeans of water slightly acidulated, which gave rise to a colourless solution, in which the prussiate of potash clearly indicated traces of iron, undoubtedly in the state ot phosphate. Ammonia gave rise to a white precipitate, evidently consisting of phosphate of lime and magnesia; for, upon redissolving it in muriatic acid and precipitating the lime by oxalate of ammonia, the filtered liquor was clouded by solution of potash ; and if into the ammoniacal solution thus separated from the LSlfS' suPP°sedL.t0 contain lhe muriates of lime and magnesia, I poured oro^?InfT°nia'!Wh'tegranU,ar Precipitate was thrown down, consisting fmm thp in.i I-8 mfa=nesla ^mained in the liquor. Thus, the ash resulting Dholhate nfZl J °f ^ ^T yielded Carbonate of lime and ™S™™> phosphate of lime and magnesia, and traces of iron." • that uTAl?£ii?ed the "atUre °i thG immediate Principles of the blood, and M Le Can III «»»e ."jum, ™}> »he exception of the fibrin and hematosine, d ores, for thi Proceeded. t0 make the complete analysis of this fluid. The P «D?vfdP innr,PUrP,°SeVaS, "T0^ by Dr' O'Shaoghnesay, is as follows : wash the oth-tr °f t-he,£1°t ,nt0 two Parls ' dr7 one, and estimate the loss ; Te fir t exh. ',h. aSCertaln the qUrHy of fibrin- As l'^e water given off from aofid maSr rwhte? '" lheSt&te ^"^ by subtracting the one proportion of i lwTS7h^nfV Pr'°US a"a,yJS1S °fthe Serum has°shown to be contained

--ffi^S^ar 3gainhL; fX ^ *Z fihrin^ermlnTb6; deration TaX' nf ^'^ °f -^ C°)°aTi^ raalter is accurately obtained* of saline Tattl" \ ^17e" we,&h.t of the crassamentum gives the quantity ui bdiine matter. —Journ. de Pharmacie S^nr i«-?i /tca l r,i > Appendix, \o. IV p 67 ""«««. &ept. Ib31. 0 Shaughnessy on Cholera, Blood ( Arterial 5 ( Venous } Macaire and Marcet. Carbon, j Hydrogen.. Oxygen. | .Nitrogen 26-3 21-7 27-20 23-87 19-68 Gelatin Albumen Fibrin

■odiom, pou..iom, ch]„™ne!f„°b' J'e"t,?"ed *"]<>>""> Phosphor-"' c"£.m GENERAL PRINCIPLES OF THE BLOOD. 29 lation than from its fluidity. The coagulation of the blood, when out of the circulation, would seem to be unconnected with life, yet life could not go on without it; for as all the solid parts of the body are formed from the blood, this could not take place if there did not exist in it the power of coagulating. Many diseases exhibit the blood coagulated in the living body, even in the vessels themselves, but more frequently when extravasated. Coagulation does not belong to the whole mass of circulating blood, but only to the part I have called coagulating lymph, which during this action commonly detaches itself from the other part, called the serum.* Whether the whole mass of the serum be a distinct part of the blood when circulating is not easily determined, as we have no mode of separating it from the coagulating lymph, while both are fluid. The serum making a part of the whole mass in the fluid state, the first stage in the coagulation is a species of decomposition, forming a separation of the serum. But, on the other hand, there are reasons for considering the coagulating lymph as distinct from the serum, even when both are fluid; since the serum can be separated from the lymph without coagulating, by many actions of the vessels, both natural, preternatural, or diseased. Thus the liquor of the amnios and that of dropsies are formed; and therefore we may conclude that the separation of the serum, when the lymph is coagulated, is not an act necessary to the coagulation, but an effect of it.f

* [This has been doubted by some physiologists, who imagine that the clot essentially consists of the central nuclei of the red globules, deprived of their external investment of colouring matter. (Prevost and Dumas, Ann. de Chim. et de Phys., xxiii. 51. Young, Med. Liter.) I do not agree, however, in this opinion : first, because there is often a real separation of the coagulable lymph from the red globules previous to these losing their form, and before coagulation ; and, secondly, because Professor Blumenbach was able, by the aid of a common microscope, to discover Jhe red globules entangled in the translucent lymph, and retaining their perfect shape after coagulation. If any separation, such as has been supposed, took place of the colouring matter from the central nuclei, the globules would not be apparent; but the whole would be obscured by a uniform solution of red colouring matter. , - - That the coagulation of the blood arises from the concretion or gelatinization of the fibrin alone is rendered evident by the fact that if fresh-drawn blood be briskly stirred by a wisp, so as to remove this principle from it, the residuary liquor will not coagulate. It may perhaps seem surprising that so small a proportion of fibrin as w^ should be capable of giving so great a degree of solidity to the whole mass; but in this respect it is nearly equalled by the substance called gelatin, one part of which, dissolved in 100 parts of boiling water, concretes into a solid jelly on cooling.] .,,,,.«.- • i t [Dr. B. G. Babington, in an admirable paper in the Medico-Lnirurgical Transactions, vol. xvi.,°p. 301, has given unanswerable reasons for believing that the serum and coagulable lymph exist in the circulating blood as a homogeneous compound, and not merely in the form of mixture, as has generally been supposed. » There is no better reason," he says, " for affirming that fibrin exists in a fluid state in liquor sanguinis [the term applied by him to this compound] than for affirming that muriatic acid exists in a solid state in muriate of ammonia. The salt indeed is solid of which the muriatic acid forms one ingredient, but the ammonia is essential to the solidity of the compound. In like manner, the com- 30 HUNTER ON THE BLOOD. The circumstances attending the coagulation of the lymph are subject to great varieties. These depend upon or correspond with the state of the body at the time, of which we can best judge by the readiness or difficulty with which the blood .coagulates, and by the firmness or looseness of the coagulum. The whole mass ot the blood being a compound, of which the parts are m some degree separated, the appearances upon coagulation are attended with still more variety than the lymph alone could exhibit, or than could occur in those animals which are not possessed of red blood, as the red part brings to view many of the changes in the lymph, by the. difference of its colour, as well as of its specific gravity. The three substances, which become visibly distinct when the lvmph coagulates, differ as to gravity: the serum is the lightest, and, remaining fluid, swims upon the top ; the red globules, which undergo no change, are the heaviest, and sink more or less in the lymph; but being entangled in it, add to its weight, so as to make it sink deeper in the serum.*

pound is fluid of which fibrin forms one ingredient, but the serum is essential to its fluidity." The compound nature of the liquor sanguinis is, I think, further shown from the fact that spirits of wine or turpentine does not immediately affect fresh-drawn blood, although they instantly coagulate the albumen of serum which has once separated from the clot. In answer to the particular objection urged by our author to this view of the subject, it may be replied : 1st, that there is as much reason for believing that the fluids of dropsy, &c, are secreted, as there is that they are simply exuded; for, 2d, these fluids differ in composition from the ordinary serum of the blood; and 3d, effusions of serum never take place without corresponding effusions of lymph, and vice versa. This latter point has been particularly discussed by Dr. Babington in the paper before cited.] * [The specific gravity of the blood has been variously stated by different experimentalists. According to Davy and Scudamore, it is from 1049 to 1051; Ure makes it 1053; Prout, 1030 to 1055; Blumenbach, 1050 ; Haller, 1053; Fourcroy, 1056; Jurin, 1054; Henry, 1053 to 1126; Whiting, 1055; Denis, 1059; Thackrah, 1041. These differences have no doubt partly arisen from variations in the state of the system at the time the blood was taken. Brande found that the specific gravity of healthy blood occasionally rose to 1071. Blood, whether buffed or not, has generally a greater specific gravity in acute diseases than under ordinary circumstances ; but the reverse obtains in diseases of debility. 1050 is the standard which will be assumed in the following notes. The specific gravity of serum is subject to scarcely less variation than that of the blood ; but I shall content myself on the present occasion with merely stating that the medium 1029-5, as mentioned by Dr. Marcet, is now generally admitted'! Dr. Davy represents the specific gravity of the red globules as 1087, of the colouring matter as 1126 to 1130, of the coagulable lymph as 1046 to 1060, and of the whole clot as 1077 to 1084. I conceive, however, in reo-ard to this latter point, that some error must have existed in the experiments0; for, as the clot floats in the serum, there cannot, it should seem, be much real difference between them : not to insist on the fact, which will afterwards be adverted to, and which Dr. Babington was the first to point out, viz., that the coagulum which results from the bnffy fluid which is skimmed off from inflammatory blood is uniform in heaS t^0"'' Whidl ^n'* Possibly happen if the fibrin were lighter or This indSSV 8efrT" (Se6 Bablng,on' Md-Ch. Trans., xvi. 298, ft. seq.) in'en ouX emXvpd 16 ^am?ntf which the gentleman above-mentioned has n .hi „. a- P yed t0 prove the homogeneity of the liquor sanguinis as stated in the preceding note, and it must be admitted to have cJnsideraWe for'ce?] GENERAL PRINCIPLES OF THE BLOOD. 31 Blood when extravasated coagulates sooner or later, according to the quickness or slowness of its extravasation, and the quantity extravasated: it coagulates late when drawn into a basin rapidly, and in considerable quantity; soon, when allowed to flow slowly, and in small quantities. This will be better understood when I treat of the principles of coagulation. When blood is received into a cup, and is thereby exposed, it certainly coagulates more readily than when extravasated in the cellular membrane or in the vessels; and on the exposed surface it coagulates more readily than anywhere else, except round the edges of the dish in which it is contained. It has been observed that the upper surface of the blood coagulates first, forming a thin pellicle, as milk does when near boiling, while underneath it still remains fluid ; but the whole gradually becoming thicker, and losing its transparency, coagulates in about fifteen or twenty minutes into a substance of pretty thick consistence. The time required will vary according to the quantity of blood in one mass and the disposition of the blood at the time.* We may observe the following appearances when the blood is coagulated. The coagulum is generally, but not always, swimming in a fluid; for it sometimes happens that the lymph does not squeeze out the serum in the act of coagulation, in which there is an act of contraction. The top of the coagulum is toughest or firmest: and it becomes less and less so towards the bottom, because there is less of the coagulating lymph at the bottom, in proportion as the red globules subside in the lymph before it coagulates. The coagulating lymph has a degree of toughness in proportion as it is free from serum; for while the serum is mixed within it, though there may be no red globules, it is not very tough; but when pressed

* [Coagulation commences in about three or four minutes on an average, and is completed in about ten. In about fifteen or twenty minutes the coagulum assumes a "pretty thick consistence ;" but it continues still further to contract and to express the serum for at least three or four hours, and sometimes much longer. The commencement of this process and the degree in which the clot afterwards contracts are subject to be influenced by a great number of disturbing causes: as, for instance, the shape and material of the vessel, the state of the system at the time the blood is drawn, the quantity of blood collected together in one mass, the rapidity with which the effusion has taken place, the temperature of the air, the partial or complete exclusion of the atmosphere, rest, agitation, foreign substances, &c. These will be considered in the subsequent notes. The period required for the blood of different animals to coagulate has been estimated by Thackrah to be, in general terms, inversely as the size of the animal. Thus, in the horse, coagulation commenced in from 5 to 13 minutes; in the ox, from 2 to 10; in the sheep, hog, and rabbit, from \ to 2; in the dog, from \ to 3; in the duck, from 1 to 2 ; in fowls, from \ to \\ ; in the mouse, in a moment. (Op. cit., p. 154.) There is also a difference in the time required for blood to coagulate from different vessels of the same animal. Arterial blood has generally been conceived to coagulate more rapidly than venous, blood from the vena cava than blood from the jugular vein, and portal blood more readily than either. Thus, while blood from the jugular vein of a dog began to concrete in from 1£ to 3 minutes, blood from the portal vein concreted immediately on effusion,] 32 HUNTER ON THE BLOOD. between the finger and thumb, so as to squeeze out the serum, it becomes nearly as tough and elastic as the coats of an artery» "j appearance becoming fibrous, and even forming laminae, and indeed appears to be very much the same kind of substance with an artery, which gives us a clear idea how a membrane may be formed, and probably can be varied, according to the impression made on it by the surrounding part?. This is one reason why the lymph, which has the strongest disposition for coagulation, is the toughest, as it parts with more of its serum. The lymph is transparent, but whether tinged as the serum is found to be we can hardly say, as it is seldom possible to catch it in a fluid state free from red globules, and never from serum, which has itself a tinge. When out of the body in a dish, where it is long in coagulating and the red globules sink fast, we find it transparent; but during coagulation it becomes more muddy, till at last it is opake, but with a tinge of colour. On being steeped in water it is often rendered very white, which would not probably be the case if it had a tinge of its own, independent of the serum. Blood usually requires a considerable time for its complete coagulation, or rather contraction; for if allowed to stand some days, the coagulated part becomes less and less, as more and more of the serum is squeezed out, which cannot arise from the serum being lighter and issuing out spontaneously, for without some expelling force it would be retained mechanically by the capillary attraction, as in a sponge. The blood which is longest in coagulating coagulates most strongly, and produces the most complete separation of its parts. In such instances, as the coagulating lymph continues longer fluid, it allows the red globules more time to subside, and the serum to be more squeezed out from the crassamentum. When the coagulation is slow, and of that kind which will be firm when completed, we may skim off the fluid coagulating lymph, free from the red globules; and the part so taken will coagulate immediately, while that in the cup remains fluid some time longer.*

* [This is not merely the coagulating lymph or fibrin, but the fibrin united to the serum, constituting the liquor sanguinis of Dr. Babington (see note, p. 29). In itself, and in its mode of coagulation, it does not seem to differ from ordinary blood, except in containing no red globules. When transferred to a globular vessel, it separates into two parts, viz., serum and crassamentum, the coagulation taking place uniformly throughout the mass; that is, every part of the coagulum exhibits the same density, and consequently every part contains the same quantity of fibrin. Hence fibrin cannot exist in a fluid state and be lio-hter or heavier than the serum ; for if lighter, the upper surface of the clot woulcf be more dense than the lower, and vice versa (see note, p. 30). Hence also the high probability that the liquor sanguinis constitutes a real homogeneous compound, and not a mere towe^d rfZ Accord,r\l0 Thackrah, more fibrin was found at the °;erjhlr °f,\he ^samentum than at the upper, and least of all in the middle endsvervP'mnohtn PPJehend'however, that the latter part of this statement Inr3.tt?'e!ken o»r confidence in these experiments. that » fhe auanmvTf I0" °f *f eo"tractility of ^ clrf, Mr. Thackrah observes, Staauonar%nUtSelLu°rtheaay anT™ ne^A^ £' th™ *** was "«"* j iuunn. aay, and on the fifth, sixth, seventh, and eighth pro- GExNERAL PRINCIPLES OF THE BLOOD. 33 Many causes have been assigned for the coagulation of the lymph, which appear to me to be ill founded. It frequently happens that when changes take place in matter of which the immediate causes are unknown, the mind refers them to some circumstances which accompany these changes, although, perhaps, they may have had no concern whatever in producing them, and may be only attendants. This will always be the case where those changes arise out of the nature of the part itself. A seed put into moist ground grows: but the moist ground is only a necessary attendant, and not the immediate cause. The life of the seed, stimulated to action by the moisture, is the immediate cause of its growth, and it continues to grow because its action is always excited. All the water in the world would not make a dead seed grow. The same mode of distinction is applicable to the coagulation of the lymph. The first observations on the blood were most probably made on that of the more perfect animals, whose heat is commonly greater

gressively diminished." Hence it seems that the contractility of the clot continues for three days, during which time serum is expelled ; but after that period relaxation occurs, and a part of the expressed serum is reabsorbed. As the degree in which the clot contracts is inversely as the rapidity of the coagulation, whatever influences the coagulation of the blood so as to accelerate or retard this process will have a corresponding influence on the contraction of the clot and the relative quantity of serum which is afterwards expressed. About 10 parts serum to 13—14 crassamentum may be assumed as the standard of health ; but, like the contraction of muscles after death, it varies infinitely in different cases. Dr. Babington found the proportion of serum and crassamentum to vary materially in the same blood drawn into differently-shaped vessels. Thus, blood drawn into a pear-shaped vessel and a common basin exhibited the following differences : Temperature of blood.rof serum Specific gravity of blood.iof serum Crass, in lear-shaped bottle. Urass. in basin To serum Vertigo during pregnancy . 87° 60 87 90 65° 60 60 60 1050 1 1049 1044 1048 1027 | 1028 1023 1024.6 1495 945 960 1292 ■2230 1716 11090 J1717 1000 1000 1000 1000 The nearer the form of the vessel approaches that of a cube or sphere, the greater will be the proportion of serum. " This difference is owing to the greater or less distance of the coagulating particles of fibrin from a common centre, which causes a more or less powerful adhesion or contraction of these particles. Perhaps few facts relating to the phenomena of venesection are of more practical importance than this, since blood is said to be thick or thin, rich or poor, in reference to the quantity of crassamentum it contains, and views of a disease are founded upon these supposed conditions, which, after all, depend not on the blood itself, but on the vessel into which it is received" (op. cit., p. 297). Thackrah found a similar diversity to arise from the composition of the recipient vessel, a circumstance which he attributed to the electric states of the different metals composing it. Thus, while one quantity of the same blood coagulated in a copper vessel in two minutes, and afforded 345.7 serum to 654.3 crass., another equal quantity coagulated in a pewter vessel in 1 min. and 10 sec, and afforded only 51.1 serum to 945.9 crass, (op. cit. p. 66).] 4 34 HUNTER ON THE BLOOD. than the heat of the atmosphere. Such blood when extravasated was found to coagulate on cooling; it was therefore natural to suppose that the coagulation of the lymph arose from its becoming colder, as happens in jelly;* but cold, simply, has certainly no effect upon the coagulating lymph. If we take a fish out of the sea, the heat of its body perhaps about 60°, and bring it into an atmosphere of 70°, the blood, on being let out of the vessels, will immediately coagulate. This was ascertained on board of a ship lying off Belleisle, in the summer of 1761; for immediately upon a fish being caught, I ascertained its heat, and letting out part of its blood, it immediately coagulated, although the blood discharged was become warmer than that remaining in the vessels of the fish'; which, however, still continued fluid. Indeed, common experience and observation show us that cold alone has no power to coagulate the blood. It often happens that particular parts of an animal, such as the fingers, face, nose, ears, &c, are cooled nearly to the freezing point, and frequently are in that state for a considerable time, yet the blood retains its fluidity in those parts, as I have experienced in my own fingers ; and indeed in those parts of an animal where the blood has been frozen, and again thawed, the blood appears as fluid as before, and circulates as usual. Heat has the power of exciting action in an animal, and we find that heat even increases the action of coagulation; for if blood be heated to about 120°, it will coagulate five minutes sooner than when kept at its natural heat, and even sooner than the blood of the same animal taken at the same time and cooled to 50°.f Mr. Hewson has laboured this point, endeavouring to show it is not cold that makes the blood coagulate, and he has laboured no less to show the real cause of such a change. He took fresh blood and froze it quickly: on being thawed, it was again fluid, but soon afterwards coagulated; this he conceived to be a sufficient proof that it was not cold which made the blood coagulate.j From the above observations and experiments, it must appear that cold, simply, has no influence whatever upon the coagulation of the blood.§

* This term has been applied to the coagulation of the blood, but I think improperly; for I should only call that jelly which became solid by cold, and fluid again by heat: coagulation is totally different, for it is a new species of combination. The freezing of blood may be called congelation. f These experiments were made on the jugular veins of dogs, by takino- a section of the veins on each side filled with blood, and immersing them in water, either warmer or colder, or of the natural heat, and observing the comparative difference. J Hewson on the Blood, p. 21. § [Sir C. Scudamore found that cold retarded coagulation nearly in the same proportion as heat accelerated it. Blood which began to concrete in 44 minutes in an atmosphere of 53°, underwent a similar change in 2^ minutes at 98° • and blood which coagulated in 4£ minutes at 98°, became solid in one minute at 120°: but blood which coagulated firmly in 5 minutes at 60°, preserved its fluidity for 20 minutes at 40°, and required upwards of a full hour for complete GENERAL PRINCIPLES OF THE BLOOD. 35 And in most of the cases in which the blood is observed to coagu late the air is commonly in contact with it: this was next presumed to be the cause of its coagulation.* But the air has really no more effect than any other extraneous body, in contact with the blood, that is capable of making an impression upon it; for the blood coagulates more readily in a vacuum than in the open air: nor will either of these supposed causes assist in explaining why it is not found coagulated after many kinds of death, nor in the menstrual discharge. Neither will they account for the very speedy coagulation of the blood which usually takes place in all the vessels after death, or when it has been extravasated into cavities, or cellular membranes, where no air has ever been admitted-!

coagulation. Hewson had observed that if blood was kept at a temperature of 38° for 24 hours it became thick and viscid, but did not coagulate upon the return of warmth ; which fact is capable of generalization, for whatever keeps the blood fluid for a considerable length of time has a tendency to deprive it of the full power of coagulation afterwards. Thackrah asserts, that blood which has once become frozen does not coagulate in any case, but only forms a grumous mass in which there is no separation of parts. (Op. cit., p. 67.) A very high temperature, as 140°—150°, according to Prater, has the same effect, that is, it renders the blood incoagulable; and, what is very remarkable, dilution with water does not restore this property in one case more than in the other (on the Blood, p. 13). It is sufficient at present to notice these facts, which have been considered by some to bear importantly on the question of the vitality of the blood. I may add, however, what is worthy of remark, as bearing on the same question, viz., that low temperatures, (insufficient to prevent coagulation altogether,) equally diminish the contractility of the clot and of muscular fibre, while the effect of high temperatures is the very reverse. Thus, animals of the order Batrachia im mediately perish and become rigid by being immersed in water at a temperature of 108° to 120°. The muscular structures of warm-blooded animals likewise become more or less contracted by all temperatures above blood-heat.] * Hewson on the Blood, p. 23. f [Hewson merely contended that air promoted coagulation, not that air was essential to the process. It must be confessed, however, that his expressions are sometimes equivocal, as at p. 123, Vol. I., and in some other parts of his Inquiry. Scudamore took two portions of blood from a man slightly indisposed, and placed one of them under the receiver of an air-pump and allowed the other to be exposed in the open apartment. The former cooled in five minutes from 84° to 75°; the latter from 84° to 82.5°. The former, however, was much the most coagulated of the two at the end of this period; although, as we have before shown, cold retards the coagulatory process. But if blood be received into a close vessel, so as completely to fill it, and care at the same time be taken to exclude it from the contact of the atmosphere, the process will be considerably retarded. To account for this apparent anomaly, Scudamore not only attempted to prove that carbonic acid is extricated from the blood during coagulation, and that the time required for the concretory process in great measure depends on the quick or slow extrication of this gas, but that its evolution is "an essential circumstance" in this process. (Op. cit., p. 103.) With respect to the fact on which this explanation turns, viz., the extrication of carbonic acid gas, nothing can be more discordant than the results of experimentalists. One party, as Vogel, Scudamore, Brande, &c, (Ann. de Chimie, tom. xciii. Essay on the Blood, p 28. Phil. Trans. 1818, p. 181,) affirming its existence in arterial and venous blood alike in considerable quantities. Another, as Clanny, Prout and Stevens, (Edin.Med. and Surg, Journ., xxxii. 40. Bridge- 36 HUNTER ON THE BLOOD. Rest is another cause upon which the coagulation of the blood has been said to depend; and although this opinion be not true in the full extent in which it has been taken, I think that rest has greater influence in the change than any other circumstance whatever. But though rest seems greatly to dispose the blood to coagulation, it is the operation of rest alone, without exposure, which we are to consider; as otherwise we shall .be apt to confound it with the two foregoing causes, viz., cold, and the contact of air.*

water Treatise, p. 524. Observations on the Blood, p. 21,) that it exists in venou3 blood only ; and a third, as Davy, Thackrah, and a number of others, (Edin. Med. and Surg. Journ. xxix. 254. Inquiry into the Blood, p. 63,) that it has no existence in either. But this question has lately been investigated and set at rest by Mr. Squire of Oxford street ; who, by a series of accurate and ingenious experiments, has succeeded in obtaining notable quantities of carbonic acid from venous blood, when, from the nature of the apparatus which was employed, it was impossible that any portion of the gas so obtained could have been derived from the atmosphere. It has been urged, indeed, that the alkalinity of the blood is inconsistent with the admission of this fact; but Dr. Davy has shown that the admixture of a fourth part of an inch of carbonic acid to an ounce of fresh blood did not destroy its alkaline properties. (Edin. Med. and Surg. Journ., xxix. 254.) Admitting, therefore, the fact of the presence of carbonic acid in the blood, the question arises how far the escape of this gas affords a reasonable explanation of the cause of coagulation. Now it must be apparent that the coagulation and non-coagulation of the blood under circumstances not at all connected with the escape of carbonic acid is a sufficient answer to this question : for if coagulation can take place in the interior of the body, where no gas can escape, or be prevented from taking place when effused from the body by the mere circumstance of cold, it is evident that the extrication of carbonic acid is not necessary for this process. Still the experiments which have been referred to render it extremely probable that coagulation in vacuo is accelerated by the free escape of carbonic acid, and that atmospheric air, in addition to its action as a foreign body, promotes coagulation by promoting the escape of carbonic acid. Magendie has observed (Phys., 4eme edit., Brux., p. 306) that enormous quantities of atmospheric air may slowly be injected into the veins of an animal without producing any inconvenience, or without imparting to the blood any tendency to coagulation; but Hewson found that blood confined within a living vessel by two ligatures remained two-thirds fluid for 3^ hours, although it coagulated in fifteen minutes when air was blown into the vessel. Hence there would appear to be a difference in regard to the effects of atmospheric air, according as the blood happens to be at rest or in motion in the vessels. As to the effect of gases generally on coagulation, Sir H. Davy has informed us that he could discover no difference in the time required for coagulation when blood was exposed to nitrogen, oxygen, nitrous oxide, carbonic acid, hydro-carbon, or atmospheric air. (Researches on Nitrous Oxide, p. 380.) Nitrous oxide injected into the veins converts the blood to a chocolate-brown colour and destroys its coagulating power. Sulphuretted hydrogen has the same effect, and renders it viscid and greenish. Carbonic oxide gives it a brownish tint. (Chrisfison on Poisons, p. 691 et seq.) When the experiment of breathing pure oxyo-en is kept up for some time, or until the animal dies, the blood in the veins is found to present the same florid hue as that in the arteries, and to coagulate with remarkable rapidity. (Broughton in Lond. Quart. Joum. of Sc. 1830 ) For the effect of other gases on the blood the reader is referred to the able work of Dr. Christison above cited, to the Recherches Chym. Phys. of Nysten and to Thenard's Sys. de Chim., iii. 513.] J ' * [The question which will here be considered is rest or stagnation of the blood within the vessels or living textures of the body. In the preceding note I have adverted to the experiments of Hewson as to th e GENERAL PRINCIPLES OF THE BLOOD. 37 Since, therefore, the blood may coagulate in the vessels either of a living or a dead body, and since it coagulates when extravasated

effect of rest combined with the insufflation of air into the living vessels. Mr. Thackrah (op. cit., p. 76) repeated and varied these experiments in the following manner. By means of double ligatures he secured the jugular veins of two rabbits and two dogs, and examined the state of the blood at different intervals. In the veins of the two rabbits the blood was perfectly fluid after 45 minutes; and in the veins of the two dogs it was perfectly fluid after 60 minutes in one case and 20 minutes in the other. Sir Astley Cooper performed similar experiments on dogs, and found the blood perfectly fluid after three hours ; although by varying the form of the experiment and allowing the blood to flow into a portion of vessel unequivocally dead, the blood was found to be perfectly coagulated in 15 minutes. The blood in the heart and vessels of struck cattle is commonly fluid for half an hour or upwards after the apparent death of the animal; although if it be effused from the vessels during any part of this interval, it speedily coagulates. In the same manner extensive extravasations of blood into the cellular membrane or into the tunica vaginalis testis remain fluid for weeks or even months, notwithstanding that the same blood when let out readily coagulates. Thus also Mr. Hunter found the blood in the stomach and intestines of a leech still fluid ten weeks after it had been sucked. It must be evident, therefore, that some other principle is concerned in keeping the blood fluid in these cases besides motion, which principle must previously be ascertained before we can determine anything concerning the effects which are due to mere rest. This principle I believe to be the vitality of the vessels, which maintains the blood in a fluid state, and counteracts its coagulating tendency in exact proportion to the energy of the system at the time, or the tonic powers of the vessels. In proof of this I shall offer the following arguments in corroboration of those which have preceded. 1st, It is well known that struck esttle retain a residual vitality in their muscles for some hours after apparent death ; consequently it is not surprising, upon the hypothesis, that the blood should preserve a fluid state in virtue of a like residual vitality in the vessels. 2d, If a leech die soon after it has fallen off, the blood in its body will be found coagulated. 3d, In asphyxia, syncope, and other cases in which the system is depressed, the blood coagulates rapidly as contrasted with those cases in which the energies of the system are in full vigor, as in inflammatory fever. 5th, Upon the same principle, the second and third cups of blood in a common venesection coagulate more rapidly than the first; but if the blood be taken in the commencement of an inflammatory attack, while the system still labours under oppression, the first cup will coagulate more rapidly than the second. In the same manner, blood from the extreme parts of the body coagulates more rapidly than that which is near the source of circulation. 6th, Fontana found that although the poison of a viper had no effect on extravasated blood, it immediately promoted coagulation when it was injected into the veins. 7th, The blood coagulates in mortified limbs, and in the capillaries of inflamed parts. The following, however, are supposed to be proofs that rest, even in the living vessels, promotes the coagulation of the blood. Kellie remarked that blood which had been mechanically impeded by the tourniquet speedily coagulated. The formation ofcoagula in the cavities of the heart and great veins during life is by no means of unfrequent occurrence, and is generally found to be preceded by some obstruction in the circulation, accompanied with a depressed state of the vital powers, (Bright's Medical Reports, ii. 63. AndraPs Precis de Pathologie, ii. 340.) Fibrinous vegetations about the valves of the heart in diseases of that organ, the formation of coagula in aneurismal sacs, the concretion of fibrinous plots in vessels which have been secured by ligature, and the coagulation of blood which has been effused into the interstices of the cellular membrane, are all evidences of the same nature. It must not be forgotten, however, that in all these cases the blood is placed under very different conditions to those which exist in a normal state, inasmuch as either the system or the parts which contain 4* 38 HUNTER ON THE BLOOD. into different parts of a living body, rest, like cold or air, might be supposed to be the sole cause of the coagulation oi the blood : yet it is not rest considered simply, but rest under certain circumstances, which appears to possess such a power; for motion given to the blood, out of the vessels, will not of itself prevent its coagulation; nor will it even in the vessels themselves, if all the purposes ot motion are not answered by it. Motion seems to retard coagulation ;*t yet we know for certain that blood will in time coagulate even in* the vessels themselves, and under certain circumstances sooner, perhaps, than anywhere else: as, for instance, when there is a disposition to mortification. In this case we find the blood coagulated even in the larger vessels. I have seen a mortification come on the foot and leg, and when it had advanced only to a certain degree, the patient died. On examining the parts above the mortified part, I found the crural and iliac arteries filled completely with strong coagulated blood: we may thence infer that the tendency to mortification in the vessels produced this disposition in the blood. If the coagulation should be supposed to have arisen from the blood being stopped in the large vessels at the mortified part, let us reflect that this cannot account for it: the same thing ought then to happen in an amputation, or in any case where the larger vessels are tied up.

the blood are diseased, and consequently not possessed of a full power of life. Hence the great difficulty of assigning the real share which rest has in producing coagulation in these cases; for the effects which seem to arise from mere rest may in fact arise from the diminished vitality of the vessels. " It is not rest considered simply, but rest under certain circumstances, which appears to possess such a power;" but when we reflect further that rest out of body has a contrary effect (see note below) we may, I think, "conclude," with Hunter, "that rest does not of itself in the least assist the coagulation of the blood." It is difficult to conceive that rest can have opposite effects on the blood in and out of the vessels.] * This is motion given to it in a vessel, without any empty space, and having beads put into it, which are shaken. f [When blood is briskly stirred or shaken immediately on its effusion, it retains a homogeneous character, and apparently loses its coagulating properties : but this appearance is fallacious; for if blood thus treated be placed on a filter, the fibrin will become apparent. It has, in fact, assumed the solid form ; but being in a state of minute division, it is diffused through the turbid liquor, and thus escapes observation. (Davy in Edin. Med. and Surg. Journ. xxix. 244.) Indeed it is very probable that coagulation is really accelerated in such cases, just as it is by a more moderate agitation. To prove the latter point, three portions of blood being taken ; the first and third were moderately stirred with a stick for two minutes, while the second was allowed to rest. The two former concreted in 3^ to 4 minutes, the latter or second portion did not concrete till C minutes, and at the end of 8 minutes the coagulum was much less firm than that of the other two. (Thackrah, p. 68.) Scudamore observed a difference of one minute. (Op. cit., p. 40.) Prater observed a difference, but it was not so considerable. (Op. cit., p. 18.) It should be noticed, however, that these experiments were made in open vessels, while those which were made in close vessels were much less decisive. Agitation promotes coagulation by bringing the interior particles of the mass into contact with the sides of the inert vessel, which will necessarily have the effect of rapidly dissipating its residual vitality. It is 0n the same principle, that a small portion of crassamentum dropped into freshdrawu blood accelerates coagulation.] GENERAL PRINCIPLES OF THE BLOOD. 39 In a priapism the blood does not coagulate, except it threatens mortification. The separation of the blood, either from itself, that is when divided into small portions, or separated from the living body, becomes one of the immediate causes of the coagulation of the lymph; therefore the contact of blood with blood, or with living vessels, in some degree retards coagulation: this is the reason why blood which comes from the vessels slowly, or falls from some height, or runs some way on the surface of a dish, coagulates sooner than when the contrary circumstances happen ; and upon this principle it is, that blood when shaken in a phial will coagulate the sooner, even if shaken in a vacuum. A deep mass of blood is also, from the same cause, longer in coagulating than a shallow one. From the above observations it must appear evident that neither cold, nor air, nor rest alone, has any influence on the coagulating power of the blood; there must, therefore, be some other principle on which this process depends; and, as it retains its fluid state while circulating, and even for a long time when at rest in the living vessels, and coagulates when the vessels or the body dies, it might naturally be supposed that it was the life of the body or vessels which kept it fluid ; we know, however, that life in the body or vessels does not hinder the blood from coagulating under certain circumstances, but often rather excites coagulation. Nor does death, in the body or vessels, in all cases become a cause of coagulation ; for we find that in many who die suddenly from a strong impression of the mind, the blood'does not coagulate; there is, therefore, something more than the mere situation of the blood, surrounded with dead parts, that allows of coagulation ; and that must be a something in the blood itself. From these observations it must be evident that the fluid slate of the blood is connected with the living vessels, which is its natural situation, and with motion ; and that where there is a full power of life, the vessels are capable of keeping the blood in a fluid state. 1 believe, however, very little motion is required to keep up this fluidity when the other is present. A total stagnation of the blood while the body is alive, as in a trance, or where the circulation has been stopped for several hours, as in the case of persons apparently drowned,* does not make it coagulate; yet where there are no actions going on in a part, if the blood stagnates for a much shorter time than in a trance, it will be found coagulated, as in mortifica-

* [It is difficult to reconcile the results of physiological experiment with the accounts which have been given of recoveries from protracted asphyxia. It is extremely doubtful, under the most favourable circumstances, whether in drowning the heart ever continues to pulsate for so long a period as five minutes after the cessation of respiration, or whether, having stopped its actions, it can ever be renewed. In trances also and the ordinary forms of syncope it is questionable whether the functions of respiration and circulation are ever wholly arrested. The statements which have been made on these subjects are certainly without foundation, and no better than extravagant fables.] 40 HUNTER ON THE BLOOD. tions; but then this coagulation is to answer a good purpose, and arises from necessity,* which appears to act as a stimulus in disposing the blood to coagulate. . , . As a proof that blood will not coagulate in living vessels, in a perfect and natural state, and ready to act when powers were restored to it, I found that the blood of a fish, which had the actions of life stopped for three days, and was supposed to be dead, did not coagulate in the vessels; but, upon being exposed or extravasated, soon coagulated. The blood of a lamprey-eel, which had been dead to appearance some days, was found fluid in the vessels, because the animal was not really dead; there had, however, been no motion in the blood, as the heart had ceased acting; but upon its being exposed, and extravasated into water, it soon coagulated:f yet, under certain circumstances in life, it has been observed that the blood will in a small degree coagulate: this is in the state of torpor. It is asserted by some author, whom I now do not recollect, that the blood of a bat coagulates when in that state; and Mr. Cornish, (surgeon, at Totnes, in Devonshire,) to whom I applied for some bats in the torpid state, sent me them, but in the carriage they always died; however, he took opportunities of examining them, and he found that the blood was in a certain degree coagulated; but it soon recovered its fluidity on motion and heat.J From these remarks, I should conclude that rest does not of itself in the least assist the coagulation of the blood, but that this effect arises from the blood being separated from the living vessels, and being deprived of motion; and that it happens sooner or later,

* By action taking place from necessity, effects are meant which arise in consequence of some unusual or unnatural change going on in the parts, which becomes a stimulus to action. The stimuli, from this cause, may vary exceedingly among themselves; but as we are unable to investigate them, I have included them under this general term, stimulus of necessity. (See note, Principles of Surgery, p. 32, and Index, art. Stimulus.) f There are some circumstances which hinder the coagulation of blood in living bodies, although extravasated. Two leeches had been applied, and had sucked till full. These were preserved for ten weeks, and then contained considerable quantity of blood, which appeared like that recently drawn from a vein, and coagulated when exposed. I have known, in tapping a hydrocele, that a small vessel has been wounded, and the blood, as it extravasated, got into the sac, and when tapped sixty-five days after, the blood has come out thickish ; but when extracted it coagulated, and separated into different parts.1 X [I am informed by Dr. Marshall Hall, that in his experiments on hybernating animals, he found the blood quite as fluid as under ordinary circumstances. This is not different from what might have been expected ; for notwithstanding that the respiration is almost wholly, if not entirely, suspended during the state of hybernation, the heart still continues to beat, and to circulate black blood, at the rate of twenty-eight strokes in a minute. (Hallm Phil. Trans. 1834.) • [A sanguineous tumour of the leg, which had existed upwards of ei'ht months, and was supposed to be a chronic abscess, was punctured by Mr. ?,Z IkM bt* George's Hospital, in the course^of the last year (1834), and about five ounces of fluid blood discharged, which immediately coagulated.] * GENERAL PRINCIPLES OF THE BLOOD. 41 according to other circumstances. It might be supposed that these are rather negative causes of coagulation than positive ones; but it is to be considered, that in a living body the cessation of a natural action, the absence of an usual impression becomes a cause of action, of which innumerable instances may be given. I have now considered the circumstances under which the blood coagulates, and shown that none of them alone, nor all of them combined, induce the blood to coagulate. My opinion is, that it coagulates from an impression; that is, its fluidity under such circumstances being improper, or no longer necessary, it coagulates to answer now the necessary purpose of solidity. This power seems to be influenced in a way in some degree similar to muscular action, though probably not entirely of that kind ; for I have reason to believe that blood has the power of action within itself, according to the stimulus of necessity, which necessity arises out of its situation. I shall now consider the simple act of coagulation, abstracted from causes. Coagulation I conceive to be an operation of life; and I imagine it to proceed exactly upon the same principle as the union by the first intention; it is particle uniting with particle, by the attraction of cohesion, which, in the blood, forms a solid; and it is this coagulum, uniting with the surrounding parts, which forms the union by the first intention; for union by the first intention is no more than the living parts when separated, whether naturally or by art, forming a reciprocal attraction of cohesion with the intermediate coagulum, which immediately admits of mutual intercourse, and, as it were, one interest. To produce coagulation of the blood, however, something more is required than merely the reverse of the causes above mentioned, as having the power to keep it fluid ; for the blood becomes in many cases instantaneously incapable of coagulation, either in or out of the vessels, even when nothing has been added or taken away, and must be therefore under the influence of some other cause. This, I believe, must be sought in some property inherent in the blood itself; besides, some natural operations destroy this principle in the blood when extravasated. , In many modes of destroying life the blood is deprived of its power of coagulation, as happens in sudden death produced by many kinds of fits, by anger, electricity, or lightning;* or by a

* [Although this statement has been impugned by Sir C. Scudamore (op. cit. p 54), yet o-eneral testimony has evinced the accuracy of Mr. Hunter s observation. Scudamore found that the blood coagulated as usual tn animals which had been killed by the discharge of an electric battery. It is worthy of remark, that electricity and galvanism rather accelerate coagulation out of the body, and also occasion a sensible elevation of temperature. . Mayo has observed, that when any accidental extravasation happens in a person that has been hanged, the blood speedily coagulates (Physiology, 3d edit. p. 26) : but Thackrah has carried the observation still further, and affirmed that such is o-enerally the case in all instances of violent death. {Up. at. p. lbb.) J 42 HUNTER ON THE BLOOD. blow on the stomach, &c. In these cases we find the blood, after death, not only in as fluid a state as in the living vessels, but it does not even coagulate when taken out of them. As in the bodies ol such persons no action of life takes place, the muscles do not contract. There are partial influences likewise which destroy the power of coagulation, as a blow on a part producing a considerable extravasation. This forms an ecchymosis, in which we shall often find the blood not in the least coagulated. In healthy menstruation the blood which is discharged does not coagulate; in the irregular or unhealthy it does. The healthy menses, therefore, show a peculiar action of the constitution; and it is most probably in this action that their salubrious purposes consist; for if twice the usual quantity is evacuated, with the power of coagulation, even from the same vessels, the same benefit is not produced, much less when taken away from another part by art.* Many substances, when mixed with the blood, prevent coagulation ; bile has this effect out of the body; but we cannot suppose that in a living body it can be taken into the blood in such quantity as to produce this effect; for we find in a very severe jaundice that the blood is still capable of coagulating strongly. That probably every inanimate fluid in nature, which is capable of being rendered solid, produces heat during that change, and iu the contrary change cold, is commonly known. It is on this principle that Dr. Black has established his very ingenious theory of latent heat. Thus, in the freezing of water heat is produced. To see how far the coagulation of the blood was similar in this respect to the same change in other substances, I first coagulated the white of an egg, by applying to it rectified spirits of wine: the heat of both was the same before their union ; but I found, upon uniting them, that the white of the egg was immediately coagulated, and that the heat of the mixture was increased four, sometimes five degrees, according as it coagulated slowly or quickly.f As the blood in the animals upon which we most commonly make our experiments is warm, it becomes a difficult matter to ascertain whether it produces heat upon coagulation. In holding the ball of the thermometer in the stream of blood coming from the arm, I found the heat raised to 92°: I then took a cup of human blood, allowed it to coagulate, and put it up to the brim in water warmed to 92°, till the whole mass was heated to this point. I bled afterwards another person to the same quantity, in a similar cup, which was put into the same water. Having two well-regu-

* [The healthy menstrual discharge, which is probably a true secretion, does not coagulate, because it contains no globules or fibrin. Brande found that " it had the properties of a very concentrated solution of the colouring matter of the blood in a diluted serum." (Phil. Trans. 1812, p. 113.) Unhealthy menstruation is attended with actual hemorrhage.] + LThe disengagement of caloric in this case is to be ascribed to the union of o!7^rj°ntA\^i ln/he a,lbumen with the sPirits of winR' and the consequent not evolveany'teat.] ^^ AlbUmCn coaSulated b? dilute "Uric acid does GENERAL PRINCIPLES OF THE BLOOD. 43 lated thermometers, one in each cup of blood, I observed which cooled first, for I did not expect so much heat to be produced in the second as to make it warmer, but conceived, if any heat was formed, it would retard the cooling of the fresh blood; but it rather cooled faster, which I imputed to the coagulated blood parting with its heat slower than the fluid blood. These experiments f have repeated several times, with nearly the same effect. I then conceived the experiment would be more conclusive if I could get blood in a fluid state which was naturally of the heat of the atmosphere, for which purpose I took the blood of turtles. A healthy turtle was kept in a room all night, the floor of which was about 64° and the atmosphere 65°. In the morning the heat was nearly the same. The thermometer was introduced into the anus, and the heat of that part was 64°. The animal being suspended by the hind legs, the head was cut off at once, and the blood caught in a basin; the blood while flowing was 65°, and when collected was 66°, but fell to 65° while coagulating, which it did very slowly : it remained at 65°, and when coagulated was still 65°. These experiments had been made several times, but not with that nice accuracy which was obtained by causing all the heats to correspond exactly; yet, as they were all known and marked down, if any heat had been produced upon coagulation its exact quantity would have been ascertained in each; and, indeed, in some it seemed to cool, but in none it became warmer. From these experiments, I should say that in the coagulation of the blood no heat is formed.* Coagulated blood is an inorganized animal substance. When the blood is thinly spread before coagulation, or oozes out on surfaces, (in which act it immediately coagulates,) and coagulates in that form, it may then be said to form an inorganized membrane, of which there are many: and organization is seemingly so simple in many (which we know to be constituent parts of the body), that

* [The change in the capacity of bodies for heat depends on the change of their densities; but no change takes place in the sum of the densities of the constituents of the blood during, or as the effect of, coagulation, for what the fibrin gains in specific weight is exactly balanced by what is lost by the serum; and were this otherwise, we should still not expect any appreciable degree of heat to be evolved, when we reflect on the extremely small proportion which the fibrin bears to the whole mass of the blood, and that it is this principle alone which undergoes coagulation. The opinion in the text has, nevertheless, been controverted by several experimentalists. Fourcroy, in one instance, observed the heat to rise during coagulation from 20° to 25° Cent., or nearly 11° Fahr. (Ann.de Chimie, vii. 147.) Dr. Gordon also, in some experiments, estimated the rise to be as much as from 6° to 12°. (Ann. of Phil., iv. 139.) And Dr. Scudamore was led to a similar conclusion, viz., "that a slight evolution of heat takes place during the coagulation of the blood." (Op. cit., p. 75.) I am of opinion, however, that the experiments of Davy on the blood of sharks and turtles, and those of Thackrah on warm-blooded animals, are more to be depended on, and these fully confirm the accuracy of Mr. Hunter's observations. (Thackrah, p. 60.) Raspail has evcil .gone into the opposite opinion, and imagined that the temperature of the > rood is actuallv reduced by the act of coagulation. (Syst. Chim. Org., p. 361.)] 44 HUNTER ON THE BLOOD. these coagula, more especially the thin ones, cannot easily by their appearances be distinguished from them. ,. The coagulating lymph of the blood being common probably to all animals, while the red particles are not, we must suppose ittrorn this alone to be the most essential part; and as we find it capable of undergoing, in certain circumstances, spontaneous changes, which are necessary to the growth, continuance, and preservation oi the animal, while to the other parts we cannot assign any such uses, we have still more reason to suppose it the most essential part ot the blood in every animal.*

* [There seems good reason for this opinion, and yet Fourcroy was unable to detect any fibrin in the blood of the foetus ; an observation which has since been repeated by different experimentalists, and confirmed by the statement of Bichat, that fetal blood does not coagulate. Dr. Grant has stated that the proportion of fibrin in the blood of the less perfect animals is considerably smaller than that which exist in the higher classes. Davy, Thackrah, and Scudamore found that the proportion of fibrin was relatively increased during inflammation. Scudamore even found that it varied during the same venesection. "In one instance," he says, "I found the proportion in the first cup for 1000 grains of clot twelve grains, and in the last cup not quite six grains: the highest proportion that I have found in healthy blood has been, for 1000 grains of clot, 4.43 of fibrin. It is in the inflammation of the fibrous textures of the body that the greatest quantity of fibrin is found in the blood; for example, in inflammation of the heart, when the blood is drawn we meet with the strongest example of the buffy coat; and next, probably, in pleurisy and acute rheumatism." (Op. cit., p. 119.) Mr. Thackrah found that this variation in the relative proportions of the constituents of the blood during the same venesection was not confined to the fibrin, but was equally applicable to the serum and haematosine. (Op. cit., pp. 146, 209.) It is remarkable, however, that the increase of fibrin, which is observable both in inflammation and in breeding animals, is uniformly found to take place at the expense of the albumen of the serum, from which it may be inferred that the former is formed out of the latter, or is in fact in a higher and more perfect state of animalization, a view of the case which is still further corroborated from the fact of its containing more nitrogen. The generality of modern chemists have been disposed to regard the fibrin, albumen, and hasmatosine of the blood as modifications of the same animal principle. In its coagulated state, the chemical relations of albumen are undoubtedly closely allied to those of fibrin, so as with difficulty to be distinguished from them : still there are certain well-marked differences which distinguish these substances; as, for instance, albumen contains less nitrogen than fibrin; it is soluble in water at common temperatures; it undergoes coagulation at a temperature of 160°, and it is also coagulated by all the mineral acids. Whether these points of dissimilarity are sufficient to characterize it as a distinct and separate organic principle, I shall not pretend to decide. I will only observe, that in deciding this question it would be right to reflect that the doctrine of definite proportionals does not obtain, in regard to organic principles, in the same manner or to the same extent as it does with respect to inorganic compounds, so that the former class of bodies are far less distinctly characterized in general than the latter, and pass, by a series of easy transitions, from one into the other, so as often to be convertible. It signifies, however, very little in fact whether we reo-ard the fibrin, albumen, and haematosine, as distinct and separate principles or merely as modifi- ^T,*!" .theLsame P'inciple. There can be little doubt that the offices which they fulfil in the economy are perfectly distinct, and therefore it is probable that the substances themselves are so. In order to explain the variations above-mentioned in the constitutonb 0f the blood during one and the same venesection, we have only to remembe^'ne ex- GENERAL PRINCIPLES OF THE BLOOD. 45 Besides a disposition for coagulation under certain circumstances, as before described, the blood has also a disposition for the separation of the red globules, and probably of all its parts; for I think I have reason to believe that a disposition for coagulation and a disposition for a separation of the red part, are not the same thing; but arise from two different principles. Indeed, a disposition to coagulation would counteract the effect, and hinder the separation of the red particles from taking place. Thus, we see that rest, or slow motion of the blood in the vessels, gives a disposition towards the separation of the red part, as well as when it is extravasated ; since the blood in the veins of an animal acquires a disposition to separate its red parts more than in the arteries, especially if it be retarded in the veins ; the nearer, therefore, to the heart in the veins the greater will the disposition for separation be, though it does not seem to retard coagulation. This is always observable in bleeding; for if we tie up an arm, and do not bleed immediately, the first blood that flows from the orifice, or that which has stagnated for some time in the veins, will soonest separate into its three constituent parts ; this circumstance exposes more of the coagulating lymph at the top, which is supposed by the ignorant to indicate more inflammation, while the next quantity taken suspends its red parts in the lymph, and gives the idea that the first small quantity had been of such service at the time of its flowing as to have altered for the better the whole mass of blood. Rest, therefore, may be regarded as one of the immediate causes of the separation.*

traordinary rapidity of the circulatory, secretory, and absorbent functions. A solution of prussiate of potash introduced into the jugular vein of a horse was detected by the appropriate test in the opposite jugular vein in from twenty to thirty seconds, and in the serous cavities of the pericardium and pleura in from two to six minutes; and if we may be allowed to judge from the effects of poisons, or from the rapid manner in which enormous ascitic collections are sometimes suddenly dispersed, the rapidity of the action of the absorbents would appear to exceed even that of the secretories. (Hering in Med. Gazette, xiv. 745.) From these sources it is not difficult to account for the change in quality which the blood undergoes during venesection, which ordinarily occupies from two to five minutes. The first portions of blood which pass are abstracted under natural circumstances; but the new impression which is thus produced on the constitution by the first loss of blood, may easily affect the residual mass;, 1st, through the medium of the absorbents; 2d, through the secretory vessels, which rapidly take up the fluid parts of the body, and convey them into the circulation.] * [Buffy Blood.—The reason why more buff appears in the first than in the second quantity of blood (a fact which is by no means universal), will be intelligiblefrom what has been said in the preceding note respecting the superabundance of fibrin in inflammatory blood, as well as from the circumstance that the first portions of blood are generally slowest in coagulating, by which a greater time is allowed for the red globules to subside. It is not difficult, however, to prove that an increased disposition to separate must also exist in the red globules, and aid in producing the buffy crust. Take, for example, blood from a patient labouring under acute rheumatism, and set it aside; in less than thirty seconds the surface will be covered with a bluish transparent lymph, although no traces of coagulation will be apparent for several minutes afterwards. Thus, Hewson found that of two portions of the same blood, one afforded a buffy crust, and the other none, although the latter remained fluid full ten minutes after the buffy coat had begun 5 46 HUNTER ON THE BLOOD. § 3. Of the Scrum.

The serum is the second part of which the whole mass of blood appears to be composed, or is one of those substances into which

to be formed on the former. (Exp. Inq., p. 90.) I think, therefore, it must be apparent that the buffy coat of blood undoubtedly depends on these three circumstances acting conjointly, viz., the increased quantity of fibrin, the slowness of the coagulation, and the increased tendency to separation. ,-„.., m. Dr. Davy (Edinb. Med. Sur. Journ., xxix.) and Dr. Stoker (Pathol. Observ., p. 37), have irrefragably proved that mere slowness of coagulation is not alone a sufficient cause to account for this phenomenon. The latter has furnished twentyseven experiments, in fifteen of which buff was formed, and in the other twelve it was not. In the former coagulation was never delayed beyond fourteen minutes, and in all but three it took place in less than five minutes. Out of the latter there were four instances in which coagulation was delayed eight, and three in which it did not take place in less than from twenty to forty minutes; the real cause, therefore, of the buffiness in the former instances was certainly not the slowness of coagulation ; yet slowness of coagulation has a very marked effect in increasing the quantity of buff; for if blood be drawn from a small orifice into a shallow vessel, the quantity of buff will be infinitely less than if it is drawn from a large orifice into a deep vessel; the difference in these cases depending in great measure on the more rapid manner in which the blood coagulates in one case than it does in the other. For the same reason Dr. Babington (Med. Chir. TV., xvi. 298), found that when blood was drawn into two vessels, one empty and the other half-filled with olive oil, the buffy crust which formed under the oil was twice or thrice as thick as that which formed in the empty jar. Nay, the same author has even gone so far as to affirm that healthy blood placed under these conditions will sometimes exhibit a buffy surface. I may also advert to one other circumstance, which is, that the quantity of buff will be greatly influenced by the shape of the vessel into which the blood is received, for it must be evident that the space left by the gravitation of the red particles will bear a proportion to the whole perpendicular depth of the blood, and consequently be much greater in one case than in another, although the same blood be employed. This circumstance is frequently overlooked in judging of the degree of inflammation from the appearance of the blood previously abstracted. To account for the buffy coat, it has been imagined that the fibrin of the blood becomes specifically lighter, or the red globules specifically heavier than usual j but nothing has been offered in the shape of proof for either of these statements. Hey attributed the sizy crust to a more intimate admixture of the constituent parts of the blood ; and Hewson to the greater tenuity of this fluid ; but both of these opinions are directly contradicted by experience, for nothing can be more clear than that there exists in the blood a greater disposition to separate into its component parts in inflammation than in a healthy state, while nothing has been more clearly proved than that the specific gravity of the whole blood is increased under the same circumstances, at the same time that the fibrin and albumen are separately and collectively in greater relative proportions than in a state of health. (Thackrah, pp. 206-212.) Rapidity of circulation is another cause which has been adduced in explanation of this phenomenon ; but rapidity of circulation does not necessarily precede a sizy state of the blood, nor would it, if it did, throw any light on the proximate cause of this appearance. The question now naturally occurs, Does the buffy crust consist of the original fibrin of the blood, or of the fibrin of the blood modified by disease, or of altogether a new substance * I think there can be no doubt that it consists of the fibrin of the blood deprived of the red globules, that is, of a net-work of fibrin containing a more or less considerable portion of serum. It is difficult to imagine that this substance has not undergone some modification from disease; for although GENERAL PRINCIPLES OF THE BLOOD. 47 the blood spontaneously separates itself. So far it appears as a simple fluid, in which light I shall first consider it; though we shall

the fibrin thus obtained does not chemically differ from ordinary fibrin, yet it is firmer, denser, more contractile, and more like an ordinary membrane than the fibrin of healthy blood ; physiologically speaking, therefore, it has undergone some modification. It would also appear from the researches of Trail, Gendrin, and Dowler, that the serum which is interposed in its meshes is more charged with albumen than the rest of the serum, although this statement has been denied by Thackrah. The ratio of solid and liquid elements in the buffy crust varies considerably in different cases, but in general there is more fibrin and less serum than in the ordinary crassamentum of healthy blood. The cases in which the buffy coat is most strikingly exhibited are those of rheumatic inflammation, and inflammation of serous and fibrous structures. The quantity of buff present may generally be considered as an index to the strength of the constitution and the acuteness of the disease conjointly ; but this is not universally the case, for the blood is very often found_to be buffed in scurvy and diabetes as well as in the latter stages of phthisis and acute diseases, so that this circumstance taken singly is an extremely unsafe guide to act on. On the other hand, it is found deficient in children, and has rarely been observed to form in arterial blood, or blood abstracted by cupping. It is also very often found to be wanting in plethoric people; in cases of small-pox previous to the appearance of the eruption; in violent and extensive inflammation, involving several textures of the body at the same time, and running into rapid suppuration ; in diffuse inflammation of the cellular membrane ; in inflammation of mucous membranes; in the first attack of the endemic and common remittent fevers of hot climates : "Imoin morbis maximeinflammatoriis, in nullo sanguine, quotiescunque misso, aliquoties crusta ulla est." (De Haen, Rat. Med., iii., c. 2.) Under these circumstances it must be apparent that the mere absence or presence of buff is no sure indication in practice, but must be judged of, like other symptoms, from concurrent circumstances. Mr. Vines (Lancet xi. 294) has stated a very extraordinary fact relating to this subject. Asses, he says, that feed on hay and live in the open air at a temperature of 45°-55° exhibit a buffy crust, which disappears as soon as the temperature is raised to 60° or depressed to 35°. Also that if an animal in health, his blood being buffy, be made to undergo moderate exercise, it will become wholly red, and will continue so for some hours afterwards. But when the circulation becomes tranquil, it will again put on the buffy appearance. If the exertion, however, be continued to an immoderate degree, the blood becomes again buffy. The fact of excessive exercise rendering the blood buffy, although it has been disputed by some, is now generally admitted. Horses, after a full gallop, have often been observed to have buffy blood. Dr. Todd and Dr. Stoker of Dublin conceive that the colour and figure of the buff may point out the seat of the inflammatiou ; but this is very questionable: others, again, have affirmed that they could distinguish buffy blood from the mere colour of the stream as it flowed from the vein. I intimated in the preceding note that the origin of the buffy crust is probably to be sought for in the conversion of the albumen into fibrin. The final intention of this provision obviously is, to answer the increased demand which is made for this substance in inflammation, as without some additional supply it is probable that the work of reparation could not go on in cases of extensive injury, nor the adhesions consequent on inflammation be duly formed. Thus, in diffuse cellular inflammation, no adhesions are formed, and no buff is observed on the blood, but the reverse of these circumstances is observable when the seat of the inflammation is in fibrous or serous structures. The Coagulation of the Blood has generally been referred to a physiological or a chemical cause. The first of these opinions was maintained by Hunter, the latter is most prevalent in the present day. In reference to the author's ideas on this subject, it will be necessary to premise a distinction between his statements as to the cause of fluidity and the cause of coagulation of the blood. The former 48 HUNTER ON THE BLOOD. find hereafter that it is composed of two substances, which in many of our experiments separate. Serum, I believe, is common to the

I think are borne out by every fact (note, p. 36), the latter are open to considerable differences of opinion. , - - .„, Having considered the effects of exterior causes on coagulation, viz., neat, cold, motion, and rest, and "shown that none of these alone, nor all of them combined, induce the blood to coagulate," he comes to the conclusion that it coagulates from an impression ;—that the blood has the power of action within itself ;—that to produce coagulation something more is required than merely the reverse of the causes above-mentioned to keep it fluid, for the blood becomes in many cases instantaneously incapable of coagulation, either in or out of the vessels, even when nothino- has been added or taken away.—There is therefore something more than the mere situation of the blood surrounded with dead parts that allows of coagulation ; and that must be a something in the blood itself.— Coagulation I conceive to be an operation of life." Now as these opinions are greatly dependent on another, namely, the vitality of the blood, which opinion has not yet been considered, it might seem expedient that I should in the first place examine the truth of this datum. I believe, however, that this will not be necessary, but that it will be extremely possible to assign a reasonable cause of coagulation without adverting, to this subject. In regard to the cause of the blood's fluidity, Mr. Hunter is perfectly clear. "It must be evident," he says, " that the fluid state of the blood is connected with the living vessels, which is its natural situation, and with motion ; and that where there is a full power of life, the vessels are capable of keeping the blood in a fluid state," &c,&c. Now if the fluidity of the blood depends, under ordinary circumstances, on motion and contact with the living vessels, (which opinion can scarcely I think be doubted,) then the conditions under which this fluid is placed when removed from the living vessels and set at rest are essentially changed, and the difficulty of accounting for the act of coagulation on simply chemical principles is entirely removed. For let it be assumed, in the first place, that the whole mass of blood consists of liquor sanguinis and red globules (notes, pp. 30, 32) ; secondly, that the liquor sanguinis is really and bond fide a compound body, and no mere mixture of elements (id.); thirdly, that the existence and integrity of this compound depends on, or is preserved by, the living vessels or other containing parts (note, p. 36.); and fourthly, that the natural or inherent condition of fibrin is that of a solid (and as yet it has never been known to exist as an uncombined fluid); admit, I say, these data and the difficulty of accounting for the coagulation of the blood at once disappears, for the cause being removed which kept the elements of the liquor sanguinis in a slate of combination, the effect also ceases ; in other words, the conditions ceasing under which this compound can alone exist, the principles of which it is constituted necessarily revert to those states which are most natural to them, which state, as regards the fibrin, is that of a solid. This opinion was first maintained by Schultz (Journ. des Prog, des Sc. Med., vi. 85), and has since found an able supporter in Dr. Babington, who has given additional reasons for believing in its truth. It is not, as might at first appear, opposed to Mr. Hunter's peculiar doctrines concerning the vitality of the blood, but presupposes and confirms them ; for without admitting the vitality of the blood, it would be impossible to explain many circumstances°connected with coagulation, and particularly why the blood does not immediately solidify on extravasation whenever it is removed from the influence of those causes which kept it fluid. But this does not happen, and therefore it is plain that coagulation, instead of being an act of life (as Hunter supposed), is in fact an act which can only take place on the cessation of life, or, in the language of our author, an act of death. A residuum of vitality certainly adheres to the"blood for some considerable time after it is extravasated from the body, and it is not until this is partially or wholly dissipated that coagulation takes place ; hence, as I have observed before, tne disposition to coagulation is always inversely as the powers GENERAL PRINCIPLES OF THE BLOOD. 49 blood of all animals; but there is more of it, I think, in those animals which have red blood ; perhaps it may bear some proportion

of the animal, and is promoted by all those circumstances which are calculated to exhaust or carry oft the living principle. But this explanation does not account for every circumstance, nor remove the specific objections which the author himself has urged against all such hypotheses. It does not, for example, account for the coagulation of the blood in the vessels of mortifying limbs, or for the incoagulability of this fluid in cases of sudden death. With regard to the first of these objections, I think we may be allowed to suppose that the effects of sympathy extend to a considerable distance beyond the mortified parts, so that these parts, and particularly the great vascular trunks, are weakened and deprived of those full powers of life which are necessary to preserve the blood in a fluid state. Many analogous cases might be adduced to show that any one part of a system of organs being injured, the effect is participated in by the whole; and I think we must refer to this principle, viz., to the sympathy which exists between the heart and its various prolongations, the great disposition which is manifested by the blood to coagulate during the existence of syncope. With respect to the second objection which has been mentioned, I confess my inability to propose any hypothesis capable of explaining the variety of circumstances under which the blood remains fluid after death. That it depends, as Hunter supposed, on the sudden and entire abstraction of life, or as Mayo has imagined, on a greater residual vitality in the solids of the body, are explanations diametrically opposed ; and totally irreconcileable, as it appears to me, with the diversity of circumstances under which this phenomenon is exhibited. The blood has been found uncoagulated in every variety of common and epidemic fever, and in almost every variety of local phlegmasia, in hanging, drowning, hydrophobia, coup-de-soleil, lightning, blows on the stomach, overwhelming affections of the mind, intoxication, apoplexy, severe and mortal injuries of vital parts, and in most cases of poisoning; and, as opposed to these, in almost every respect in overdriven animals, typhoid and low fevers, cholera, scurvy, death from putrid food or putrid inoculations, &c. The former for the most part are examples of the sudden extinction of life attended with all the signs of previous health, the latter of the gradual decay of life attended with all the evidences of previous debility. There requires, therefore, evidently some more general principle than has yet been discovered to explain these diversities. The chemical and physiological explanations are in this respect both on a par; they both equally fail, as theories, in explaining all the circumstances of the case. Mr. Hunter compared the coagulation of blood to union by the first intention, and in a larger sense to the act of nutrition and organical formations; but this opinion, as I shall have occasion hereafter to show, does not seem to be supported by any sufficient data. At present I shall content myself with remarking one striking difference, which is, that organized structures when once formed continue to live and to manifest an interior activity, whereas the blood when once coagulated undergoes the common changes of dead matter. The act of coagulation has also been compared to muscular contractility ; but it differs from this in two essential respects : first, in not being followed by any relaxation ; and secondly, in not being stimulated to action by any of those agents which are apt to excite muscular contraction. It is further remarkable that prussic acid and extract of belladonna, one of which is so fatal to life, and the other so destructive of muscular action, do not in the least prevent a strong contraction of the coagulum; but according to my judgment, no other argument is required to subvert the physiological hypothesis, than the fact that blood which has been kept fluid for an indefinite period of time by common salt, may yet be made to coagulate by the addition of water. It is remarkable that blood may be kept fluid and of a bright arterial colour for many months, or even years, by this means, and yet retain its coagulating property.] 5* 50 HUNTER ON THE BLOOD. to the quantity of red particles in the blood, and may be of use to dilute it.*

* I shall take the liberty of extending the inquiry which is suggested in the text, to the following points: . ...___Q,.oro ;n th* First, As to the relative proportion of nutritive to non-nutrit.ve matters in the blood under different circumstances of age, sex, constitution, fitc., Secondly, As to the relative proportion which the red globules bear to the serum; x. e ,, Thirdly, As to the variations which may occur in the quantity of albumen in common serum; and Fourthly, As to the relative quantity of salts. The data on which my observations on these points will be founded may be seen at large in M. Le Canu's second memoir on the blood, contained in the Journal de Pharmacie for October, 1831. I. As to the relative proportion of nutritive to non-nutritive matters m the blood under different circumstances of age, sex, constitution, &c. 1000 parts of healthy blood being taken, the proportion of water and salts to the nutritive matters (fibrin, globules, and albumen) varied— 1 Water. Salts. Nutr. matt. i ♦ t • a- -a i f A-e C Max......853-135 1st, In individuals of dif.) ... 778-625 ferent ages and sexes. ^ A^'rage of20*analyses 796-846 2d, fjs

In individuals of <u the same sex but-^ ^ of different ages. I ji Max. ML 22 . . Min. ML 58 . . Average of 10 analyses

Max. ML 50 . . Min. ML 26 . . 353-135 790-394 804-371 9-760 11-541 10316 137-105 209-834 192-838 9-760 11 -220 9-944 . | 805-263 778-625 L"* £ Average of 10 analyses! 789-320 12-120 11-541 10-689 137-105 198-386 185-685 182-617 209-834 199-991 It appears, therefore, from the above table, that a variation of 72-729 in 1000, or nearly 7i per cent., in the nutritive parts of the blood is consistent with a state of health, and that the blood of males is richer in this respect by 14-306 in 1000, or nearly l£ per cent., than females. Age (within the period of twenty to sixty years) does not seem to make much difference. The proportion of nutritive matters in the sanguine is about 1 per cent, more in the female, and 1$ per cent. more in the male, than in those who are lymphatic. Venesection and considerable hemorrhages have a marked effect in impoverishing the blood of its nutritive parts. Thus, the blood of a patient who had been subject to copious uterine hemorrhages (pertes uterines) yielded only 137-120 parts, or nearly 5 per cent. less than the usual average, while the blood of another patient was impoverished as much as 4 per cent, after a single venesection. These facts accord with experience, and afford a rational account of the advantages of depletion in cases of over-excitement. The principal change in the blood in cholera consists in the great relative increase of the solid parts and deficiency in the carbonated alkalies, the fibrin, albumen, and colouring matter not undergoing any chances which can be detected by chemical analysis. Thus, the average of the following analyses shows an extraordinary increase of the solid contents in choleric blood": C 660 } r 34 Water . . . \ 74-9 \ solid contents < 25 ( 48-1 ) ( 52

iTh1^ S HUle les!than doub,!e the ordi"ary quantity. From other observaones to Jin? ni,hPP,rr *? ■ 3CUle dlsea*es generally tend to increase, and chronic ones to diminish, the nutritive parts of the blood. Thackrah has related a case GENERAL PRINCIPLES OF THE BLOOD. 51 The serum is lighter than the other parts of the blood, and therefore swims above them when separated. It is commonly separated of pleurisy in which the proportion of serum to crassamentum was as 10- to 54-9 (op. cit., p. 197) ; and according to Langrish the relative quantities of serum to crassamentum in acute fevers, tertians, and quartans, were respectively as 10 to 33, 10 to 25, and 10 to 16. Of sixteen cases of acute disease taken indiscriminately from ordinary practice, only one fell below the ordinary standard, while the average of solid contents for 12 out of the 16 was 207-9 in 1000, the healthy standard being estimated at 160. (Thackrah, p. 208.) The blood is proportionably more rich in those who have long fasted than in those who have recently eaten ; in wild and predatory animals, in persons who subsist on rich animal diet, and in females during the period of utero-gestation. Sickness, syncope, salivation, insufficient nutriment, and, above all, hemorrhage, impoverish the blood. The blood of a calf which was killed 16 hours after a copious venesection and subsequent refusal of food, afforded only 3-4 crass, to 10 serum, instead of the usual proportion of 8 to 10. II. As to the relative proportion which the globules (inclusive of fibrin) bear to the serum. 1st, In individuals of different ages and sexes. Max....... Min....... Average of 20 analyses , 2d, In individuals of the same sex but -{ of different a<res f C Max. ML 53 . . . ' Female. 1 Min. Ml. 22 . . . I Average of 10 analyses

rMax. Mi. 40 . . . Male, s Min. Ml. 34 . . . {_ Average of 10 analyses Red globules. Serum. 148-450 68-349 124-227 851-550 931-651 875-773 129-999 68-349 115-963 870010 931-651 884-037 148-458 115-850 132-491 851-550 884-150 867-509 It appears, therefore, that the superior richness of the blood of men depends principally upon the superabundance of the red globules, in the proportion 16.528, or upwards of 1^ per cent. The proportions of this element of the blood are not influenced so much by age (within the limit of twenty to. sixty years) as by the temperament of the individual. In the sanguine it exceeds by nearly 2 per cent. in the male, and 1 percent, in the female, the proportion in theleucophlegmatic, a conclusion which strikingly corroborates the opinion of Hunter that the red globules are in some manner connected with the strength or vital energies of the individual, while it points out also the importance which this element probably has on the full development of animal heat. Dr. Christison found that the changes which were wrought on the air by respiration were always in proportion to the quantity of red globules present in the blood ; while MM. Prevost and Dumas ascertained the fact that birds (which are the most active of, all animals, and possess the highest range of animal temperature,) have the greatest number of red globules, next to them carnivorous quadrupeds, and least of all cold-blooded animals. The constitution does not easily repair considerable losses of the red globules. A single venesection reduced their amount nearly one-third, and a severe uterine hemorrhage upwards of 34 per cent. In a case of purpura hemorrhagica, Dr. Whiting found that the red particles did not exceed 40 in 1000 parts of blood, although the common proportion was estimated at not less than 100 to 130. (De Sang. Mgrorum.) Mr. Andrews found that the red globules were diminished upwards of 50 per cent, in calves after the fourth venesection to syncope. (Dubl. Journ., No. 19.) Their quantity is also much diminished by improper or insufficient nutriment, obesity, chronic diseases, and the absence of solar light. III. As to the variations which may occur in the quantity of albumen in common 52 HUNTER ON THE BLOOD. from the coagulating lymph when that fluid coagulates, and is therefore almost always found when the blood is taken out ot tne serum.—The serum essentially consists of water and albumen, the proportions of which preserve a remarkable uniformity both in health and disease, l tie deference in the quantity of albumen seldom exceeds 2 per cent, even alter considerable losses of blood. It is sometimes deficient in milky serum, and in the serum of patients suffering from dropsy, attended with albuminous urine. In the former cases the albumen is apparently converted into an oleaginous principle, and in the latter into fibrin. The specific gravity of the serum in such cases is generally exceedingly low. Dr. Babington found that milky serum varied Irom 1019 to 1024, and that in a case of albuminous urine it did not exceed 1020 at 60°, nor the solid contents amount to more than 1-61 per cent., the usual averages being 1029-5 spec. grav. and 10-00 per cent, solid contents. (Med.-Lhir. Irans., xvi. 57, 315.) M. Denis is of opinion that albumen predominates in the young and aged, and suggests that it may probably depend on a transference of this substance from the crassamentum to the serum, the former being most abundant in adult life. (Sur le Sang, pp. 288, 290 ; see note, p. 44). IV. As to the relative quantity of Salts.—The uses of the salts of the blood can only be. conjectured, for we have very little knowledge on the subject. Dr. Stevens indeed has spoken on this matter with much confidence, and assigned to the salts of the blood an importance inversely proportionate to their quantitative amount, appropriating to them the office of preserving the blood in a fluid state (On the blood, p. 6), of rendering it stimulating to the heart (pp. 14, 43), of giving to it its scarlet colour (p. 8), and of influencing in some unknown and indefinite manner the nutritive and respiratory functions (pp. 43, 51, et passim). The ground on which these statements rest is, that " in every part of the world where healthy blood has been analysed, it has invariably been found to contain a given proportion of certain salts." Now there certainly appears to be some mistake here respecting the fact, for if by given proportion is meant a fixed proportion, this is contrary to experience. It is not indeed to be doubted that the salts of the blood are sometimes deficient in cholera and other malignant fevers, but in order to constitute this any argument to prove that fevers and cholera depend on this cause, it will be necessary in the first place to prove that the salts are never deficient in a healthy state, and secondly, that this variation in regard to the salts is greater than what occurs in regard to the other elements of the blood. With respect to the first of these points, I may observe that the extreme plus and minus quantities of salts present in healthy blood, according to Le Canu, were 11-11 and 5-10 in 1000 parts,—allowing, therefore, of a difference of just one half. But, according to Dr. Thompson, the diminution of the quantity of salts in cholera blood was very inconsiderable (Phil. Mag., May, 1832) ; while, even in the two cases which are reported by Dr. O'Shaughnessy, the proportions were 5-60 and 2-92 in 1000 parts of serum (Report on Malignant Cholera), the average standard being, according to Le Canu, 9-01. The utmost diminution, therefore, of the salts in cholera did not amount to more than 2-18 below the minimum, or 6-09 below the average standard of health. Now, as a cause of disease, this is surely not to be compared with the extraordinary increase already mentioned of solid contents, or the extraordinary disorganization of the blood in other respects. The truth is, that neither the increase of solid contents, nor the diminution of the saline, are to be looked upon as causes, but rather as effects of the disease. The serous, and therefore the saline, parts of the blood pass off by the stools, but the cause of these stools must necessarily be antecedent. The second condition is equally incapable of proof, for beyond all' question, every other element of the blood is subject to as great a variation as the salts, and much greater. Thackrah has referred to two cases of cholera in which there was an increase of solid contents to 400 and 500 in 1000 parts of blood which is considerably more than double the common average, and exceeds the' maximum quantity of healthy blood much more than the deficiency of salts in disease falls short of the minimum quantity of this element in a healthy state of thesys- GENERAL PRINCIPLES OF THE BLOOD. 53 blood-vessels, and kept together in a considerable mass. When the lymph coagulates strongly, we commonly find more serum, because it is then squeezed out more forcibly than when the coagulation is formed loosely; it is not, however, necessary for the lymph to coagulate, in order to separate the serum, for we find that it separates in disease, as in the dropsy. It is separated also from the mass of blood in uterine-gestation, being the fluid in which the foetus is immersed or swims.* I have seen it separate from the remaining mass before the coagulation of the lymph. I observed once in the blood of a lady, that a separation between the two fluids almost immediately took place, the serous part swimming on the top, while the lymph remained still fluid. From this appearance I had pronounced that there would be a great deal of buff, supposing that the transparent fluid at the

tern. The fibrin, according to Le Canu, varies from 1-360 to 7-235 consistently with a state of health, and according to Dr. Whiting, it sometimes rises from 2-8 to 6- or even 9-7 in acute rheumatism and pleurisy. An equal variation is observable in regard to the haematosine and red globules. Shall we, then, make no account of these alterations in the primary constituents of the blood, because the salts happen to be affected at the same time, especially when we reflect on the known and paramount importance of these substances'? With all respect for the abilities of Dr. Stevens, and for the contributions which he has undoubtedly made to our knowledge of the blood, I cannot but regard his reasoning on this subject as liable to the greatest objection. Dr. Prout has indeed bronght forward some happy illustrations concerning the effect of infinitessimal quantities of foreign matter in modifying the composition of organic bodies, from which it may fairly be inferred that the salts in the blood perform an important, although to us as yet unknown, office in the animal economy. This distinguished chemist has even gone yet further, and endeavoured to assign a particular use of one of the individual salts; for having remarked that chlorine or muriatic acid is sometimes evolved during the process of digestion, he thinks it probable that the muriate of soda undergoes decomposition in the stomach ; the chlorine or muriatic acid being secreted into this ergan to aid in the act of digestion, while the soda is retained in the blood to confer on this fluid its alkaline properties. (Bridgewater Treatise, p. 499.)] * [The average specific gravity of serum being taken, at a temperature of 60°, as 1029-5, that of hydrocephalic fluid varies from 1000-5 to 1019, a middle term being most frequent. The fluid of hydatids is about 1004, sometimes not containing a trace of albumen. Effusions into the chest 1019 to 1024, and ascitic effusions 1014 to 1026. The ratio of serum to crassamentum is extremely variable, depending on many circumstances. Whatever accelerates the coagulation diminishes the contractility of the clot; to which head belongs the shape of the receiving vessel. " If this be shallow, the crassamentum will be abundant; if approaching the form of the cube or sphere, it will be scanty. This difference is owing to the greater or less distance of the coagulating particles from a common centre, which causes a more or less powerful adhesion and contraction of these particles." (Babington, he. cit.) There is also another circumstance to be considered ; for in proportion as the form of the vessel departs from that of a sphere, the blood is subjected to a more extensive contact with dead matter, which accelerates the coagulating process. Hence the quantity of clot is inversely as the mass of the blood ; because when the mass is small, the surface of contact is usually great. The actual quantity of fibrin in these cases is the same; but the quantity of serum involved in the interstices of the clot is greater in one case than it is in the other.] 54 HUNTER ON THE BLOOD. top was coagulating lymph; but I was mistaken, for when the lymph was coagulated, there was no buff, and the transparent fluid remaining at top, proved to be the serum. In this there could be no deception, as there was no butt, or size; for if there had been size at the top of the coagulum, it might have been supposed that this fluid, which appeared so soon atter bleeding, had been the coagulating lvmph, and that the serum had been separated in the act of coagulation as usual. The serum is commonly of a yellowish colour, sometimes more so than at others; and this I should conceive arises from the substances dissolved in it,* by means of the water it contains; for it probably suspends every salt soluble in water, many of which are dissolved in it. If serum be not coagulable in itself, though it contains a large quantity of coagulable matter, vet I conceive it to be in a more fluid state when circulating. As it is separated from a compound mass, it appears in this respect to be somewhat similar to the whey of milk, though not exactly. This fluid undergoes no spontaneous changes, but what may arise from its separation from the coagulating lymph, except putrefaction. Though not coagulable in itself, yet one of its properties out of the body is to coagulate upon the application of certain substances. This is the principal change it undergoes ; and during this process, it more or less separates into two parts, one of which is not coagulable by such means. The coagulable part, which I now mean to describe, seems to be in some degree the same with that in the white of an egg, synovia, &c, and many other secretions, but not exactly; for those secretions contain, as I conceive, a quantity of the coagulating lymph united to them, which makes them in part coagulate after secretion; and the further coagulation of those secretions afterwards, by mixture with other substances, is owing to this part of the serum. Though the serum is coagulable under certain circumstances, and with certain mixtures, yet this power or effect may be prevented by other mixtures. Heat, to a certain degree, coagulates this part; and probably this is the only test necessary to know whether a fluid found anywhere in the body, not coagulable in itself, is this part of the serum; but as many substances do also coagulate it, I shall mention a few of them, although to me their effects do not seem to throw any light on the subject. Heat coagulates the serum at 160° or 165°; it stood at 150° for some time perfectly fluid. There is a great deal of air contained in the serum, which is let loose by heat; but not when it is coagulated by other means. The serum which was a little whitish coagulated in that degree of heat necessary for separating its air, which was extricated in very large quantities. This coagulum becomes first like the synovia, and then thicker. Many substances which do not coagulate this part of the serum do * The red globules are suspended without being dissolved in the serum, in which they are commonly examined. GENERAL PRINCIPLES OF THE BLOOD. 55 not, however, hinder its coagulation by heat; such as vinegar, acid of lemon, salt of wormwood, nitre, sea-salt.* Serum coagulates with spirits of wine, in about equal quantities, into a sort of curd and whey, which upon heating becomes something like a jelly, but the spirit seems to evaporate. It coagulates with volatile spirits into a milky fluid, which becomes like a jelly upon heating; it requires a greater proportion of the spirit than the serum, and the spirit seems chiefly to evaporate. When mixed with salt of hartshorn it does not coagulate with heat, but makes a large effervescence till the whole is formed into froth. This again becomes a fluid by the froth subsiding, but at last it forms a sort of coagulum which is not tough. Being mixed with water, and let to stand for twelve hours, it coagulates like pure serum upon heating. If this be mixed with sal. cornu cervi, as above, it rather becomes

* [According to the best analyses, synovia and the white of egg do not contain any fibrin, consequently these substances have no resemblance to the coagulable lymph of the blood. Undiluted albumen coagulates at a temperature of 160°, and is rendered opake at 212°, even when diluted with 1000 parts of water, unless excess of free or carbonated alkali be present, in which case it will not be coagulated by heat. (See Burrows in Med. Gazette, xiv. 555.) It is a singular fact that serum when diluted with 20 parts of water is not precipitable by a temperature of 165°. Galvanism and the mineral acids are very excellent tests of the presence of albumen, and so are the solutions of the ferrocyanate of potash and corrosive sublimate. Albumen diluted with 2000 parts of water may easily be detected by the two latter. The mode in which heat, galvanism, alcohol, acids, and a variety of other agents produce coagulation of the albumen has long been the subject of debate. The most general, and, as it appears to me, the most rational, explanation of the matter is as follows, viz., that the albumen of serous fluids is held in solution by means of a free alkali; but by heat the free soda of the serum is transferred to the water or united to the carbonic acid of the atmosphere; by acids it is neutralised, and by galvanism it is attracted to the negative pole of the trough. However, this explanation is not quite satisfactory. Dr. Bostock has shown not only that excess of acetic acid does not coagulate albumen, but that the quantity of free alkali present is too inconsiderable to produce the effect ascribed to it. Others have supposed that alcohol and acids coagulate albumen by abstracting the water ; but it is possible to desiccate albumen by slow evaporation without necessarily destroying its distinctive property, which is that of being again soluble upon the addition of water. The mineral salts do not merely precipitate albumen from its solution, but chemically combine with it, so as to produce specific compounds. Dr. Turner has suggested " that albumen combines directly with water at the moment of being secreted, at a time that its particles are in a state of minute division ; but as its affinity for that liquid is very feeble, the compound is decomposed by slight causes, and the albumen thereby rendered quite insoluble. Silica affords an instance of a similar phenomenon." (Elem. ofChem. 4th edit., p. 868.) But the cases are not analogous. Albumen admits of being dried at a temperature below 150°, and even of being heated to 212°, without losing its solubility; whereas silica remains perfectly insoluble after it has once been precipitated. The truth seems to be that albumen is one of those compounds which allow of a new arrangement of their molecular particles with exceeding facility, similar to muscular fibre, which is rendered permanently rigid by a temperature at least 20° below that which is required to coagulate albumen. It is scarcely therefore correct to say that albumen before and after coagulation are identical substances.] 56 HUNTER ON THE BLOOD.

more fluid, and continues so for a long time, with a strong effervescence; but it forms at length into a jelly or paste although^not a solid one. Here I suspect that the salt is evaporated, and likewise the water in the paste, so that it is not a true coagulation \Y hen mixed with common water it is coagulated by hea ; but the water separates with the other substance, and does not unite uith the

^Up^ne coagulation of the serum by heat I have observed that it separates a fluid which is not coagulable by heat, and I have reason to believe by none of the other means, viz., spirits of wine, &c, though this is not so easily ascertained ; for the other coagulating substances, as spirits of wine, &c, are applied in a fluid form, and therefore a fluid may remain after the coagulation of the serum, which might be supposed to be the fluid separated ; but from other experiments it is proved that those substances coagulate the coagulating part and unite with the other. It is also observable in meat, either roasted or boiled, that when cut there flows from it a fluid more or less tinged with the red part, commonly called gravy. I conceived that this must be different from the coagulating part of the serum, believing that the heat had been sufficient to coagulate it; but I chose to try it further, and therefore gave it such heat as would have produced the effect if it had been coagulable by heat; but I found it did not coagulate. The fluid separated from the coagulable part of the serum, I conceived to be the same with this. Thus, then, I saw there was in the serum a matter coagulable by heat, and a fluid which was not so. Pursuing the above observations on dressed meat, I observed that the older the animal had been, the more of this fluid was contained in the meat. In lamb we have hardly any of it, in young mutton of a year old but little; but in mutton of three, four, five, or six years old, it is in large quantity: in veal also we have but little, while we have it in great quantity in beef. But perhaps we know less in general of the age of our beef than of our mutton.* t

* It may be observed here that this is very different from the jelly formed in boiling or roasting meat; that which forms the jelly is part of the meat itself, dissolved down in this very fluid, and the water in which it is boiled; and we find that this effect is just the reverse of the above, for in young meat there is most of this jelly. f [This fluid, which is termed the serosity, may be obtained from the coagulum by gentle expression. It contains a little muriate of soda, a little free alkali,and about one-fiftieth of its weight of animal matter, principally albumen, which is immediately coagulated by galvanism or the mineral acids. Brande supposes that the albumen is held in solution in this case, as in the serum, by virtue of the free alkali which is present; but Dr. Bostock has objected to this view of the case, for reasons which have been adverted to in a previous note. The serosity does not appear to merit any particular attention. The basis of muscular fibre, or meat properly so called, is fibrin, which is insoluble, except in very minute quantities, by the continued action of boiling water. Jelly is a solution of gelatin, which is a distinct animal principle, with which young animals abound, but which, according to Prout, is a less animalized product than either albumen or fibrin.] GENERAL PRINCIPLES OF THE BLOOD. 57

Poultry is commonly killed young in this country, therefore we have not the comparative trials ; but in wild fowl, and what is commonly called game, we find the above observations hold good. I likewise observe that animals which have not had exercise, such as house*lamb, veal, &c, have less of this fluid than those of the same class which have been allowed to go at large. Nothing can be drier than the English veal, though kept to a greater age than anywhere else; while it is juicy in every other country, though killed much younger. In many of the trials respecting the coagulation of the serum, I observed that it had in some cases much more coagulum than in others; and of course a less proportion of the fluid part that separated, and vice versd; from the above observations too I conceived that a deficiency of this fluid part bespoke a greater quantity of coagulating matter in the serum ; and to ascertain this I took the serum of persons of different ages. This fluid, like the serum itself when united with the coagulating lymph, appears only to be mixed with the serum; for it is separated in the living body for many purposes of the economy; it is not therefore serum in another form, but a distinct fluid, which before coagulation is mingled with the serum, and seems to make a part of it. The following experiments are, perhaps, not perfectly conclusive, for many were obliged to be made on blood taken from those who were not perfectly in health; peculiar dispositions in the body may make a material difference in the serum. It is probable, however, that disease may not have any great effect upon the serum; for I found, from experiment, that the serum of blood taken from a person labouring under an inflammatory complaint, and the serum of blood in a case not at all inflammatory, were nearly the same respecting coagulation and the quantity of matter not coagulable by heat. The serum of a man fifty-six years of age, who had met with a slight accident, and was of a healthy constitution, coagulated by heat almost wholly into a pretty firm coagulum, separating only a small portion of that fluid which is not coagulable by such means. The serum of the blood of a man seventy-two years of age, of a healthy constitution, hardly coagulated by heat, became only a little thicker, and formed a small coagulum, adhering to the bottom of the vessel. With spirits it formed but a very small quantity of coagulable matter. On putting about three-fourths of water to the blood of the person aged fifty-six, and heating it as above, it coagulated much in the same way with the serum of seventy-two. The serum of a boy fifteen years of age coagulated wholly; there was hardly any of the fluid, part that could be squeezed out; at the same time I coagulated the serum of a man sixty-three years of age, in which there was but a small quantity of the fluid part. Conceiving that the whey of milk, made with rennet, was the serum of the blood, I made experiments on it analogous to the above. 6 58 HUNTER ON THE BLOOD. I heated some of the whey, and found it formed a coagulable matter, which floated in flakes in a fluid, which did not coagulate uy this means. , As this less coagulable fluid is a substance hitherto not taken notice of, and makes perhaps as interesting a part as any ol the whole mass of blood, it will be necessary to be more descriptive in giving an account of it than of the other parts. Urine does not coagulate by heat; but as I found that it coagulated with the extract of Goulard,* and as I also knew that this extract coagulated the whole mass of the serum, I conceived that the fluid in question might be similar to urine, and that the coagulation of the serum might be owing to the coagulation of this part: I therefore put the fluid to this test, and found that it was coagulated by the extract, which led to a series of experiments. As several fluids, apparently different from each other, appear to be thrown out from the blood on many occasions, I wished to see how far they consisted of the common serum, viz., of a pretty equal quantity of matter coagulable by heat, or principally of that coagulable by Goulard's extract; I therefore collected the several kinds; not only those which may be called natural, but also those proceeding from disease, which appear more like serum than the others. Of the natural, I took the aqueous humor of the eye, and first heated it in a spoon, to see what quantity of coagulable matter by heat was in it, and I found it became gently wheyish: therefore it had a small portion of matter coagulable by heat; but upon adding the extract to it, it coagulated immediately. The same exactly happened with the water in the ventricles of the brain; and also with the tears. Wafer was taken from the leg of a dropsical boy, who was extremely reduced by a compound fracture of the opposite thigh-bone, which water was much clearer than any serum. Upon heating it in a spoon over a candle, it became a little wheyish, and had a few flakes of coagulum floating in it. The water from the abdomen of a lady, which was a little wheyish, coagulated before it gave out its air; but the coagulum was not one-half of its quantity. In another rase of ascites, the water coagulated wholly, although not to a firm coagulum. Water drawn from the abdomen of a gentleman, which was pretty clear, when held over a lamp to coagulate, became at first wheyish. The liquor amnii has but very little coagulable matter in it. In coagulating all the above kinds of serum by heat, and taking the incoagulable parts and putting extract of Goulard to them, they coagulated immediately.! * What led me to the above knowledge was mixing this extract of Goulard with solutions of gum arabic in water for injections, when I found that the whole always became a solid mass; while injections with saccharum saturni had not that effect. I then tried it upon many other vegetable juices, and found it coagulated every one of them. In some of these experiments I put some of the fi?ff-. .Vni°..a V?ssel where there was some urine> and I found that when tne extract had been in too large a quantity, the urine was also coagulated. «np9„Vnfer T Tre y examP,es of lhe precipitation of albumen or mucus by means of Goulard's extract in variable proportions ] J GENERAL PRINCIPLES OF THE BLOOD. 59 Whether this fluid is of the same specific gravity with the other I do not know ; for though when part of it is coagulated by the extract of lead it is the heaviest, yet as it is united with the lead, it may acquire its additional weight from this union. The use of the serum is probably to keep suspended and undissolved the red globules; for we find it in largest quantity when these globules are most abundant. It is also intended to suspend and dissolve any foreign substances in the blood, whether they are of use to the body or otherwise, acting upon them as a common solvent. Thus we see in a jaundiced person the serum is yellower than common. When a person has taken rhubarb the same thing happens. It is probably the solvent of all our secretions. I conceive it to be unnecessary to say how much water enters into the composition of the blood. In order to constitute a perfect body or compound it is necessary that all its parts should be in due proportion. But as the blood in many animals is made up of four distinct parts, viz., the coagulating lymph, serum, which we find is composed of two parts, and the red globules, each must have its due quantity of water when in a perfect state; and I think it is probable that the lymph and red part cannot have more water than a certain quantity, but that the serum may be diluted with any proportion of it. Yet, as serum, it can have a certain proportion only; and indeed this was in some degree proved by the experiment of mixing some water with serum, and then coagulating the whole with heat: the water separated and did not make a part of the coagulum. Some of the juices of a living animal, whether circulating or out of circulation, as those which lubricate surfaces, are in a volatile state while the animal is alive ; for when the scarf-skin is taken off, the part soon dries; and if the skin is removed from a newkilled animal, it immediately dries; or if a cavity is opened, the surface of the cavity dries quickly ; this shows that some part of the juices must have evaporated from the surface: but let the animal cool before it is skinned or the cavity is opened, and then give it the same degree of heat that it had when alive, you will find, on taking off the skin, no immediate sensible evaporation, but the parts so exposed will remain moist. This volatility I conceive therefore to be connected with life, and not with the circulation : for that is stopped in both cases before the experiment. Whether it is this volatile part that gives the smell that most recently killed animals have upon being skinned or opened I do not know; but it may be observed that it follows the same rules, for if the animal is allowed to cool it loses this smell, although warmed to the same degree of heat as when alive.*

* [The halitus, or vapour, which is emitted from fresh-drawn blood, is of this kind, and consists almost exclusively of water holding in solution minute quantities of animal matter and salts, together with a peculiar aromatic principle. It occasionally happens that this effluvium is exalted to a very intense degree, 60 HUNTER ON THE BLOOD. The serum of the blood is sometimes wheyish, and then upon settling it often throws up a white scum like cream. 1 his was most probably first observed in the human blood, but is not peculiar to it. Although these appearances pretty often happen, yet lew instances fall under the observation of one man in the common course of bleeding. When they have occurred to myself I have made inquiry after the state of health of the patient, as well as examined the nature of this change and whether there was any variety in it. So far as I have been able to observe, it can hardly be said to have anv leading cause; having found it, however, more frequently in the blood of breeding women, I conceived it might have some connexion with that state; but I have seen it in others, and sometimes in men. Yet it is possible that the state of pregnancy may adapt the constitution for forming such appearances, as well as for producing other symptoms in the blood like those of inflammation ; for we often find the same effect or disease arising from various causes which have no immediate connexion with each other. There have been many opinions formed about the nature and cause of this appearance of the serum. It has been supposed to be occasioned by chyle not yet assimilated; but it does not occur frequently enough to be attributed to this fluid. Mr. Hewson supposed it to be absorbed fat or oil; which certainly is not the case, for it is not the same in all cases.*

so as to occasion headache, sickness, fainting, dysentery, and even death. In suppression of urine it acquires a strong urinous character. Orfila and more recently Barrueil (Ann. d'Hygiene, i. 274, 550. Revue Mid., Sept. 1829,) have attempted to establish the possibility of distinguishing the different tribes of animals by the peculiarity of smell disengaged from blood-spots or stains upon the addition of strong sulphuric acid. The odour which exhales is said to resemble strongly the perspiration or respiration of the animal from which the blood is derived, which in men having dark hair and complexions and in carnivorous animals is said to be peculiarly characteristic. M. Leuret, in order to test the accuracy of M. Barrueil's assertions, sent four specimens in phials containing ox blood, horse blood, and blood from the human subject both male and female. M. Barrueil detected the two former, but in regard to the two latter he mistook the male's for the female's ; a mistake, however, which, under the circumstances, strongly confirmed his own views of the case, for it so happenpd that the man from whom the blood was taken was fair, whereas the woman had dark hair and was remarkably strong. These statements have been supported by Leuret and Chevallier, and as stoutly denied by Raspail, Villerme, and Soubeyan, so that considerable doubt at present hangs over the subject; and evidence founded on these data would not, I apprehend, be admissible in a court of justice on any medico-legal question. (Raspail, Ckim. Organ., d. 383. Ann. des Sc. d'Obser. 1829, ii. 183, 465.) V Blood-spots on linen clothes or steel instruments may be distinguished from any other marks : 1st, by the evolution of ammonia on dry distillation ; 2d, by the effects of acids and neutral salts on solutions of the colouring matters ; 3d, by the usual tests for albumen ; and 4th, by blood scaling off from steel instruments °"* rng ,heated' and leaving them tolerably clean and free from rust.] f^Sfj T -mVlky serum would apPear to dePend on certain principles w£chTnde? °lre) naturall7 P^ent in the blood (see Analysis, p. 26), but marked case of thi? kTTTI* ""P8"*"™* ™ the system, "in a very well SatteTs at ?hrL ^ nd.' DJ' ?ablngl°n estimated the proportion of oleaginous matters at three per cent, of the whole serum. (Med. Chir. Trans, xvi., p 46); GENERAL PRINCIPLES OF THE BLOOD. 61 The globules forming this wheyish appearance are not of the same specific gravity in every case; for though they always, I believe, swim on the serum, and often on water, yet they sometimes sink in water. The white cream that swims on the top of the serum I believe to be formed after the serum is separated from the mass, for if it existed as such prior to this, it would be retained in the coagulum, as the red globules are, which is not the fact, and therefore it does not exist in the blood while circulating. I bled a little woman who seemed half an idiot, and was big with child: this happened in the afternoon, about three or four hours after she had eaten some veal cutlets. The day following I went

Dr. Traill, in two other cases, estimated it at 244 and 4-50 percent. (Edin. Med. and Surg. Journ., xvii. 235, 637. April, 1823), and Dr. Christison at five per cent. (lb., October, 1829.) The proportion in healthy serum does not exceed .257 or about one-quarter per cent. Milky serum varies in specific gravity from 1019 to 1024, that of healthy serum being 1029-5. This loss of specific gravity in milky serum is apparently dependent on a corresponding deficiency of albumen, and affords an example of the easy convertibility of one animal principle into another under peculiar conditions of the system, somewhat analogous to the conversion of dried fibrin, and perhaps also of albumen, into adipocere, by digestion with ether and alcohol (see note, p. 52). Dr. Babington did not observe that the degree of milkiness bore any proportion to the quantity of oily matters present. By agitating serum aud ether together, and decanting and evaporating the latter, the oily matter may easily be obtained. Collected on bibulous paper or amianthus, it may be burned like any other oil. When the quantity of oily matter is very considerable the blood is observed to have a chocolate or milky colour even while flowing from the vessel; which is a clear proof that the oil primarily exists in the blood, or in other words that it is an educt and not a product of the processes for obtaining it. (Le Canu in Journ. de Chim. Med., June, 1835.) The circumstances under which milky serum has been observed to exist are so unlike as to render it impossible to assign any probable state of the constitution as leading to its production. (Journal de Pharmacie, No. X.) Marcet, Berzelius, and Thackrah have partaken of the opinion that this appearance is derived from a mixture of unassimilated chyle with the blood; a conjecture which derives some support from the fact that chyle taken from an animal which has recently fed on fat animal diet presents precisely similar appearances. Mr. Thackrah has affirmed " that when the lacteals are fully distended (in dogs), this cream-like appearance is almost always presented in the blood. Indeed, we may generally produce it at will by taking blood a certain time after a full meal." (Op. cit., p. 130.) The same appearance had also frequently been observed in the serum of animals that are very fat. Dr. Prout regards the fatty matter of chyle as incipient albumen. From some cause therefore, such as the absorption of a peculiarly rich chyle after a full meal, or the sudden and temporary increase in the action of the absorbents, an undue proportion of fat is absorbed and carried into the blood, where, being suspended in the serum in the form of an emulsion, it becomes visible. M. Raspail endeavours to account for this appearance upon the supposition that an acid is generated in the blood which saturates the free alkali of the serum and precipitates the albumen. The irregularity of the action of the absorbents is well exemplified by several cases recorded in the 4th volume of the Dublin Journal of Med. and Chem, Science, in which extraordinary quantities of fatty matters were discharged by the bowels. In the Annali Universali a case is related in which thirty pounds weight of fat were discharged from the bowels in twenty-four hours. "The patient nearly sunk, and his skin hung in folds as though all his fat had been at> eorbed."] Go HUNTER ON THE BLOOD.

to see the blood, and found the serum of a milky-white, with a white pellicle swimming at the top like cream. I bled a lady in the arm, who XN as six months gone with child. It was about two o clock in the forenoon: she had onlv eaten a dry toast and drank a cupot chocolate for breakfast, about ten o'clock, which was our hours before she was bled. On seeing the blood the next day, I found it inflamed rather more than is common in women who are pregnant,and I also found a thin white scum on the top of the serum ; this scum I examined in the microscope, and found it to be globular. 1 diluted it with water, and found the globules did not dissolve as the red globules do. I put some of them into water, and found that they rose to the top, but not so fast as in the serum. About six days after I bled the same lady again, after she had eaten the same kind of breakfast, and about the same interval of time from it. The blood was still sizy, but the serum had no white appearance at the top. I examined the wheyish serum taken from the blood of a man at St. George's Hospital, who had received a severe blow on the head, which had stunned him, but had produced no bad symptoms. In this serum, when viewed in the microscope, I could not observe anything like globules or flakes, although the magnifier was a deep one. The red globules when mixed with it were the same as in common serum. It dried uniformly like size. Blood was taken away from the arm, being of no particular quality, except in having a wheyish serum, and was allowed to stand quiet in order to see the spontaneous changes of this serum. The white part came to the top like cream, being therefore lighter than the serum, and was very white when collected. When viewed in a microscope it was plainly globular, but the globules were smaller than those of red blood. They did not seem to be dissolved when mixed with water, as red globules are. Thomas Skelton, a publican, forty-seven years of age, being rather lusty, and subject to frequent colds, attended with coughs, hoarseness, and a discharge of matter from the lungs or throat, but otherwise enjoying a good state of health, was attacked with a violent cold, together with a difficulty of breathing, for which he applied to Mr. Wilson, apothecary, who took twelve ounces of blood from his arm, which relieved him greatly. He had taken some bread and butter, with some tea without milk, about four hours before he was bled. The blood coagulated firmly, and the serum which separated was of a white colour with a yellowish tinge, appearing like the colour of cream; upon the top of thisfloated a white scum, like another cream. On viewing this cream in a microscope it had a flaky appearance ; it did not coagulate sooner than common serum. In spirits of wine a white mixture was produced, which, on standing, fell to the bottom of the glass: this most probably arose from the serum, with which it was mixed, coagulating. The globules of white serum differ from the red globules in colour, specific gravity, size, and in not dissolving in water. GENERAL PRINCIPLES OF THE BLOOD. 63 To see how far this is chyle, it would be proper to try the chyle in the same way in serum, &c. After dipping a bit of blotting-paper into the cream, and absorbing all of it, and also dipping a piece of the same paper into the serum, and drying them, I burnt them both, to see if one burnt more briskly than the other; but there appeared to be no difference. The white part of the white serum sunk in water.

The red part of the blood I choose to consider last, although it has been more the object of attention than the other two, because I believe it to be the least important; for it is not a universal ingredient in the blood of animals, like the coagulating lymph and serum, neither is it to be found in every part of those animals which have it in the general mass of their blood.* The blood, as I have already observed, in those animals we are most acquainted with appears to the naked eye to be a red mass of fluid, having a part which coagulates upon being extravasated. The red part, however, may be washed out of this coagulum, so as to leave it white; and this shows that the blood is not wholly red, but only has a red matter diffused through its other component parts.f

* The blood of the insect tribe of every kind is free from any red parts, as is probably that of most animals below them; yet it has been asserted and supposed that their blood contains globules, although not red. I have examined the blood of the silkworm, lobster, &c, and with considerable magnifying powers, but never could discover anything but a uniform transparent mass.* t [The red colouring matter, or haematosine, of the blood in the higher animals is not diffused through the whole mass, as in the class Annelides, but belongs exclusively to its globular particles, constituting the external or investing tunic of their fibrinous nuclei. This matter, when separated from the other parts of the blood and dried, is a tasteless, inodorous substance, red by transmitted and dark garnetcoloured by reflected light, very soluble in water, and capable of being preserved a great length of time without undergoing any change from the putrefactive process. Dissolved in 50 parts of water it begins to coagulate at a temperature of 149°, and is precipitated in the form of insoluble brown flocculi. Prevost and Dumas have attempted to show that the colouring matter is not really dissolved in the water, but exists in a state of extremely minute division ; so that though the fragments ure sufficiently small to pass through a filter, they are yet plainly discernible through the microscope. I have already observed that haematosine is now generally regarded as a modification of the albuminous principle. According to Berzelius it contains about -625 per cent, of iron, in some peculiar state of combination, which may be rendered manifest by the appropriate reagents for this metal, after decolorating the mixture by chlorine gas. The same authority states that a [See Professor Grant's Lectures on Comparative Anatomy, as reported in the Lancet, 1833-4, vol. ii., p. 868 el seq., where the existence of globules in the blood of insects is assumed as an indisputable fact. See also Bowerbank in Entom. Mag., i. 239, who not only admits their existence, but affirms that they lose their peculiar elliptical form, and acquire the form of those of Mammalia when they are deprived of their external envelopes.] 64 HUNTER ON THE BLOOD. Any further information we receive concerning the red part of the blood is by means of magnifying glasses, which appear to give a good deal of information. They show us that the red pait is composed of bodies of a globular form, swimming in the lympn and serum of the blood. This circumstance of the red part having form probably led anatomists to pay more attention to it than it deserves; as if they could thence explain any essential principle in the blood or animal economy. . , . This knowledge is of late date; for such examinations of minute bodies could only have taken place since the invention and application of magnifying-glasses. Malpighi was probably the first who employed the microscope for this purpose ; and he, in 1668, wrote a description of the appearance of the globules in the blood-vessels of the omentum, which he mistook, however, for globules of fat. Microscopical observations were pursued with great ardour by Antonius Van Leewenhoeck, who saw the red globules, August the 15th, 1673. These early observers probably imagined more than they saw.

400 grains of colouring matter yielded on incineration five grains of ashes, which on accurate analysis were found to contain Oxide of iron...............50-0 Subphosphate of iron.............7-5 Phosphate of lime with a small quantity of magnesia . 60 Pure lime................20-0 Carbonic acid and loss............16-5

1000 (Med. Chir. Trans., iii. 216; Engelhart in Edin. Med. and Surg. Journ., Jan. 1827; and Rose in the Ann. de Chim. et de Phys., xxxiv. 268.) The exclusive presence of iron in this element of the blood, joined to the known tendency of the peroxide of this metal to form salts of a red colour, has generally induced chemists to suppose that the colour of the blood is due to this cause. Those who wish to consider the arguments on this subject are referred to Berzelius (ubi ut supra) and Dr. Bostock (Physiology, i. 460). I shall here only observe, 1st, that the tints produced by reagents on the blood and on the compounds of iron are wholly dissimilar; and 2dly, that the intensity of colour is too great to allow us to refer it to the minute quantity of iron present in the blood. Dr. Ure has ingeniously suggested that the colour of the blood may possibly depend on the sulphocyanate of potash, this substance having been discovered in the saliva, at the same time that it strikes with the peroxide of iron a very deep and abundant tint much resembling that of the blood. Dr. Williams, on the authority of Dr. Maton, mentions " the case of a lady whose perspiration, when profuse, dyed the clothes on some parts of her person, particularly the wrists and neck, of a bright crimson colour, which was supposed by Dr. Prout to be caused by the sulphocyanate of iron." (Med. Gazette, xvi. 724.) But the explanation of this subject by Mr. Brande is by far the most plausible. He supposes that the tint of haematosine is owing to a peculiar colouring principle, capable, like cochineal or madder, of acting as a dye and of combining with metallic oxides. Pieces of calico impregnated with solutions of corrosive sublimate or nitrate of mercury, and afterwards immersed in an aqueous solution of haematosine, acquired a permanent dye of a fine lake-red, unchangeable by washing; nnd solutions of oak bark gave a colour very nearly equal to that of madder and tolerably permanent The Armenian dyers have for a long while been in the habit of employing it in combination with madder, in order to insure the permanency of that colour. (Phil. Trans. 1812.)] J K GENERAL PRINCIPLES OF THE BLOOD. 65 When an old opinion is partly exploded and a new one brought forward, it becomes only necessary to see how far the new one is just; because if it be not proved, we must revert to the old opinion again, or to some other. Mr. Hewson has been at great pains to examine the blood in the microscope, and has given us figures of the different shapes of those globules [Phil. Trans. 1773, p. 303]; but there is reason to think he may have been deceived in the manner I have just mentioned. The red globules are always nearly of the same size in the same animal, and when in the serum do not run into one another as the oil does when divided into small globules in water. This form, therefore, does not arise simply from their not uniting with the serum, but they have really a determined shape and size. This is similar to what is observed of the globules in milk; for milk being oily, its globules are not soluble in water; neither do they consist of such pure oil as to run into each other; nor will they dissolve in oil. I suspect, therefore, that they are regular bodies, so that two of them could not unite and form one. What this property in the red part is I do not know, for it has something like the nature of a solid body; yet the particles seem not to have the properties of a solid, for to the touch they yield no feeling of solidity. When circulating in the vessels they may be seen to assume elliptical forms, adapting themselves to the size of the vessels; they must therefore be a fluid, with an attraction to themselves while in the serum which forms them into round globules, yet without the power of uniting with one another, which may arise from their central attraction extending no further than their own circumference. If they are found, however, of an oval figure in some animals, as authors have described, that circumstance would rather oppose the idea of their being a fluid having a central attraction ; but this is probably an optical deception. Whatever their shape is, I should suppose it to be always the same in the same animals, and indeed in all animals, as it must depend upon a fixed principle in the globule itself. Hence the less credit is to be given to those who have described the globules as being of an oval figure in some animals; for they have also described them as being of different and strange shapes even in the same animal.*

* I am led to believe that we may be deceived by the appearances viewed through a magnifying glass; for although objects large enough to be seen by the naked eye'are the same when viewed through a magnifying glass which can only magnify in a small degree, yet as the naked eye, when viewing an object rather too small for it, is not to be trusted, it is much less to be depended upon when viewing an object infinitely smaller brought to the same magnitude by a glass. In such a situation, respecting our eye, all the relative objects by which the eye, from habit, judges with more nicety of the object itself, are cut off The eye has likewise a power of varying its forms, adapting it to the different distances of the parts of an object within its compass, making the object always a whole; but a magnifying glass has no such power. For instance, in viewing a spherical body, a magnifying glass must be made to vary its position, and bring in succession the different parts of the hemisphere into so many focal points, every part separate not having the same relative effect on our organ of vision as when they are all 66 HUNTER ON THE BLOOD. The globules of the blood are endowed with a number of properties. They are the only part of the blood which has form or

seen at the same time ; and the eye, under such circumstances, being unable to vary itself sufficiently to alter the focal distance of the glass, is the reason why rounded bodies appear of different shapes, giving the shape only of the part that ia within the focus of the glass, placed upon an undefined plane; and it it shou Id have more focal points than one then there is an increase of parts; and this will vary according to the opacity or transparency of the body. It may also be remarked that from habit our minds are informed by the necessary actions of our body; therefore the eye, taking on the necessary actions (as it were instinctively), adapting itself at once to the circumstances of the object, gives an intelligence to the mind, independent of the real impression of the object; so that both the mipression and the consequent action give information. But this cannot be effected by glasses; for the different focal distances of the hemisphere do not accord with those to which we vary our eyes in adapting them to the distances of the different parts of a rounded body. We are, therefore, left to the impression alone, which is new and consequently imperfect, the centre being too near for the circumference to be seen at one distance, and the circumference, when seen, bringing the centre within the focus, so as to obscure it: for an eye with a given focus which can vary it in a certain degree when viewing objects alone, yet when looking through a magnifying glass of any power must now vary the distance of the object according to the magnifying power in the glass, the eye not being able to vary the focal distance of both: and this, probably, in an inverse degree to the magnifying power of the glass. This may be observed to take place in very short-sighted people, for in them the eye has the least variation respecting distance. A rounded body may be just of such a size as shall have either of its parts out of the focal distance of the eye, and must be moved to and fro alternately before the centre and circumference can be seen; and indeed it is only having a spherical body, of a size proportional to the length of focus, to produce the same effect in every eye. The appearances in a transparent flbdy when viewed through a magnifying glass are still more fallacious than of an opake one: for an opake body gives only the reflected light, which however will vary according as the rays come on the object. The moon, an opake body, gives us various shapes, and therefore shows only the light and shade arising from the irregularity of the surface ; but a semitransparent body, like a red globule, gives both the reflection of the light from the surface and also the refraction of other rays of lights, which vary according to the direction of the light thrown upon the object respecting our eye. In some transparent bodies we have still a greater variety, for we have both the reflex and the refracted light, and these vary according to the distance of the object from the eye or the distance of the light. If the transparent body is not perfectly round, or is by any circumstance broken in the uniformity of structure on which transparency depends, which I conceive happens to the red globules when diluted in the serum, then the different reflections and refractions will give to the eye the impression of so many shapes.b

b [The improvements which have been effected in the construction of microscopes by the adoption of achromatic object glasses has only partially removed the scepticism which still justly attaches to observations made with this instrument. There still exist the greatest imaginable disagreement between the statements of different microscopical observers. " An historical detail," Dr. Bostock observes, " of the errors into which this instrument has led even those who have been the most skilful m its application, would have the effect of inducing us to place little confadence in hypotheses and speculations which are derived from objects which can only be detected by the use of high magnifiers." No one I imagine that haa examined the conflicting accounts which have been given respecting the globules of the blood will be disposed to doubt the justness of this observation. Hewson, Home, Meckel, Bauer, Prevost, and the greater number of authorities GENERAL PRINCIPLES OF THE BLOOD. 67 colour; two properties which are ready to catch the eye and render the mass more visible. In the living body, by making it an

describe the globules of the blood as consisting of a central nucleus surrounded by a transparent vesicle; Hodgkin affirms that they are flattened cakes, and rejects the notion of a vesicle; others that they are elliptical, spherical, or ovoid; and others again that they are mere rings with central depressions, or mere discs with central elevations. . The same discrepancy is observable in the accounts which have been given of the size of these bodies. Twine estimated their diameter at j^f to Tpto of an inch, Bauer Wott> Hodgkin ^ Cavallo „V* Rudolphi T?W to tht'oo, Wollaston » o, Prevost and Dumas T0»,„ Raspail ^00 to ^0, Haller, Home and Kater *' , and Young „»„• Amidst these discordant statements it would be absurd in any one to pretend to accuracy. The following account, therefore, of these bodies by" Professor Mayo can only be regarded as an approximation to the truth ; and I take the liberty of inserting it in this place, first, because it accords most accurately with my own observations, and, secondly, because it approaches as nearly as possible to the mean of all the preceding observations. "The form of the globules (in man) may be compared to a silk-worm s egg. They are circular and extremply thin, with rounded edges and a central depression on either flat surface. Their diameter is very exactly ^0\0 part of an inch. They are flexible, and, when rolling upon their edges, are often bent in such a manner that they appear to consist of a central nucleus projecting from a thin disc. Plate II., fig. 5-10 [which see] represents six squares of a glass micrometer, each side of a square being ?J6 part of an inch. In the squares 5, 6, 7, different appearances of the particles of the human blood are delineated, their central depression, and various positions in which they may be seen when rolling down an inclined surface—fig. 8, 9, 10, represent the particles of the blood of a skate; they appear to differ from the particles of human blood principally in being of a larger size, in their oval outline, and in the oval figure of their central depression.' (Outlines of Human Philosophy, 3d edit, p. 23.) The size and shape of the globules differ very remarkably in different animals. In the skate, for example, they are elliptical and about twice as large as in human blood. In fishes they are about *0l00 to ^00, and in the frog about Ti0>of an inch in diameter; in the water-sow they are about ten times as large, and in the land salamander, nearly thirteen times as large as those of the human blood. These last are the largest which have yet been discovered. It may be observed that the globules are larger in all cold-blooded animals, and represent the oval or ellipse more decidedly than those of mammalia. Sir Everard Home has stated that the blood-globules, when they have discharged their external envelope of colouring matter, are disposed to coalesce like beads in a row, so as to form fibrils; from which he was led to believe that the ultimate muscular fibre was composed of these corpuscles lineally arranged, an opinion which has been participated in by MM. Prevost and Dumas, Dutrochet, and many other eminent physiologists. Dr. Hodgkin agrees as to the fact of the disposition of the globules to form piles or rouleaux, but affirms that this disposition only exists when they are in their entire state . Sir Everard Home has also stated, upon the authority of Bauer, that a different and smaller series of globules (lymph-globules) are generated during coagulation, being in diameter about „i ff of an inch. These are said to be generated in greatest abundance immediately after coagulation; but Professor Faraday has observed them to form so late as the eighth or tenth day ; and Dr. btevens, who examined them by the solar microscope, found that they were equally numerous at all periods, and as abundant as the red globules. He says they varied in size amongst themselves, the largest being at least six times larger than the smallest ; but then the latter resembled the globules in rain-water, which are generally believed to consist of air in a state of very minute division. The prevalence of globules in several of the animal secretions, and in chyle, 68 HUNTER ON THE BLOOD. object of sight, they give some idea of the motion of the blood in the smaller vessels, where it is much divided; being there viewed

has led some physiologists to suspect that these particles are identical with the blood globules; those which are found in the secretions, as the milk, th9 semen, &c, being deprived of their external tunics of colouring matter, while those which are found in the chyle are destined to receive these tunics during the blood's passage through the lungs ; nay, the globular structure of the ultimate textures of the body has even induced some to suppose that these particles of the blood form the pabulum of nutrition, not merely of the muscular fibre, but of every other part: but these are mere conjectures, too vague and indefinite to support any physiological argument, which not only do not advance science, but tend rather to retard it, by seducing the mind from the substantial evidence of facts into the ideal regions of imagination. The diversified magnitudes of the globules, according to micrometrical measurement, not only in the blood of different, species, but in the textures of the same animal, are circumstances clearly against the notion that these constitute the ultimate molecules of organic structures; not to add that the structure of many parts is such as not easily to admit the red globules at any period of their growth. In reference to the objection urged by our author to the solidity of the globules, viz., that they show no disposition to coalesce, I may observe first, that when the capillary circulation is viewed under a good microscope, the globules are often observed to meet and repel one another, from which it has been supposed that the principle of life may confer (like electricity) a new power of repulsion on these bodies, or at least control the aggregative tendency; and secondly, that the nature of the circulation must be admirably adapted to diffuse the globules through the whole mass of the blood, as well as to prevent their coalescence in any particular part. It is not, however, necessary to answer specifically this or any other objection in order to prove the solidity of the globules, for if they were not solid, it must be evident they would always assume the form of spherules, and those spherules would always be of the same size; whereas the fact is, the shape and size of the globules are different in almost every different species of animal, but uniformly the same in the same species; not to mention that the colouring matter of the globules forms a leading constituent of the blood, and may be collected and examined like any other solid body. The spontaneous volvular and rotary movements which have been observed in the globules of the blood and semen by G. L. Treviranus, Schultz, Dutrochet, Tiedemann, and other microscopical observers, must (if true) materially tend, with the circumstances before mentioned, to promote their diffusion through the whole mass of blood. (Revue Med. i. 136-8.) These movements are conceived by the German physiologists to be as much spontaneous and a property of life as the movements of the infusorial animalculae. But Brongniart has shown that the granules which issue from the pollen of plants, when it explodes in water, are equally endowed with an automatic motion ; and Brown, that all impalpable molecules, whether organic or inorganic, are endowed with the same kind of inherent or self motion, by virtue of which they exhibit a variety of gyratory evolutions when placed on the surface of liquids. If, therefore, these observations of Brown are correct, the idea of an intestine vital motion in the globules of the blood must be abandoned ; but as the Germans have attributed a variety of effects to this cause, it will be necessary to revert to this subject when speaking of the circulation of the blood. Magendie says that a number of globules are developed in the serum of the blood by the action of galvanism very similar to those of the blood (Phys., p. 234) ; and a similar result was experienced by Prevost and Dumas on applying galvanism to the white of an egg. (Ann. de Chim., xxiii. 53, and Bib. Univ. Jwllet, 1821.) Raspail regards the globules not as organized particles, but as particles of albumen undissolved in, or precipitated from, the serum, and has attempted to show that albumen, dissolved in an excess of hydrochloric acid, forms minute spherical and equal globules, scarcely distinguishable from the globules of GENERAL PRINCIPLES OF THE BLOOD. 69 with microscopes, the red globules are seen moving with different velocities in different parts, and taking retrograde or lateral motions, according as mechanical obstruction or those arising from contractions in the vessels may happen to retard or change their motion. They are heavier than the coagulating lymph, and of course heavier than the serum ; which is known by their falling to the bottom of the cup when blood is taken out of a blood-vessel. This allows the coagulating lymph to be seen more or less at the top, and produces on the surface various hues, according as the red globules subside. When they subside much, the buff is then of a yellowish colour; when the buff is thin at the top, then we have the red globules shining through it, of various colours, such as blue purple,* &c, according to the reflection or refraction, which is according to the depths. In healthy blood, however, the coagulum is commonly formed before the red part has time to subside; but we may always observe that the lower part of the mass contains more red globules than the top, and will sink more quickly in water. The red globules do not retain their globular form in every fluid, but are dissolved and diffused through the whole; and this probably happens sooner in water than in any other fluid. The red globules are not soluble in the serum of the blood, yet it is not the only fluid in which they are insoluble ; the urine does not dissolve them; but urine might be supposed to be principally serum. Water itself, however, ceases to dissolve them when saturated with many of the neutral salts, or with some of the acids. The red globules are not soluble in water mixed with common sea-salt, sal ammoniac, Epsom-salt, nitre (potassae nitras), Glauber's-salt (sodae sulphas), soluble tartar (potassa tartaras), Lymington-tartar; nor in the fixed vegetable alkalies when saturated with fixed air. As they do not dissolve in

the blood. " If a portion of the albumen of a pullet's egg," he says, " be placed in an excess of hydrochloric acid, it will at first form a white coagulum, but presently it will be dissolved by the acid acquiring at the same time a violet colour, which passes into blue. If the hydrochloric acid be then poured off, and left to evaporate spontaneously, it will deposit a white powder, which, when observed by the microscope, will be seen to consist of spherical globules, of uniform size, and which the most practised eye might well mistake for the globules of the blood." The same phenomenon is also noticed when lactic acid is saturated by barytes; " the precipitation in this case is composed of beautiful globules, some of which even show a nucleus in their centre." (Org. Chem. transl. by Dr. Townsend (p. 406). Dr. Elliotson observes, that " one takes breath while reading M. Raspail, after the strange and varying statements of so many experimenters, especially of those who use "microscopes" (Physiology, p. 148); but the justness of this eulogium may I think be questioned. M. Raspail has entirely failed to account, let, for the colouring matter of the red globules ; 2d, for their precipitation; 3d, for the difficulty with which they are regenerated, although the regeneration of the albumen is easily effected; 4th, for their importance in relation to the function of respiration, and the production of animal heat; 5th, for their various forms and sizes in different animals, and their uniformity in these respects in the same animal; and 6th, for the presence of iron in one and not in the other.] * The blood in the veins, when near the skin, gives the same hues. 7 70 HUNTER ON THE BLOOD. the serum or urine, it might be imagined to arise from the neutral salts which they contain; but I should believe that neither of these fluids has a quantity sufficient for that purpose. The vitriolic acid does not dissolve the red globules when diluted so low as to have less pungency of taste than common vinegar. The red globules are soluble in common vinegar, but take a longer time to dissolve than in water; and they also dissolve much sooner when the vinegar is diluted with water. In muriatic acid, diluted so as to be more pungent to the tongue, and three times stronger than the vinegar, the red globules are not dissolved, but lose their red colour: by adding more water to the red globules, they dissolve ; lemon juice dissolves the red globules: all this, however, throws but little light on this part of the blood. When the globules are put into water they dissolve, which destroys their globular form ; it is therefore the serum, and probably the coagulating lymph also, when circulating, which confines them to this form ; but when the serum is diluted with water they dissolve in it; and this appears to take place at once, as quick as water unites with water.* I could not observe that it was like the solution of a solid body, as a salt, for instance : a drop of blood requires about two drops of water added to it to dissolve its globules : if urine also be diluted with water, the globules dissolve in it. However, after standing some days the globules dissolve both in serum and urine; but I think later in the last. When the globules are not dissolved in any fluid the whole looks muddy, not transparent; but when dissolved in water the whole is a fine clear red. What are the properties of the serum, and those other substances that preserve the red part of the blood in a regular form, I do not know.f The red globules, when dried in the serum, and moistened in the same, do not again resume their regular form ; nor do they dissolve in it, as they do in water, but form rather a sort of flakes. As the serum and solutions of many kind of salts do not dissolve the red globules, I conceived that it might be possible for them to resume their globular figure (after having been dissolved in water), by adding such a quantity of serum as to make the proportion of water

* [According to Dr. Young, the outer coat only, or colouring matter, is dissolved by water, in consequence cf which the central (fibrinous) nucleus becomes spherical, and specifically lighter than water. Sir Everard Home states that the globule loses id in diameter, and |ds in substance, whenever it is deprived of its colouring matter by solution.] f [Many circumstances induce the belief, that the cohesion of the colouring matter of the globules to their central fibrinous nuclei is a manifestation of vitality. In adynamic fevers, in cases of death from poisoning, and under many other circumstances, this cohesion is destroyed, in consequence of which the colouring matter of the blood transudes through the coats of the veins, or else exudes into the serous cavities. Under such circumstances also, the blood, when abstracted from the body, instead of coagulating, is apt to let fall a pulverulent deposit, and to pass rapidly into a state of putrefaction. I have already observed that the catamenial fluid is devoid of red globules, and consists merely of a solution of colouring matter.] GENERAL PRINCIPLES OF THE BLOOD. 71 very little; but I could not produce this effect, although the menstruum was such as not to dissolve fresh globules. The red globules not dissolving in the serum, nor in the coagulating lymph, become separable from those parts when circulating, and therefore may be prevented from going where the coagulating lymph passes in a natural state, which they certainly do not,* and which also is the reason why they are so perfectly retained in the coagulum when extravasated. The globules, besides being heavier than the serum, and the coagulating lymph, appear to have more substance; for they do not lose so much upon drying, and when dried with serum they give a kind of roughness to the surface, which serum has not by itself. They appear not to be a natural part of the blood, but, as it were, composed out of it, or composed in it, and not with it; for they seem to be formed later in life than either of the other two; thus we see, while the chick is in the egg, and the heart beating, it then contains a transparent fluid before any red globules are formed, which we may suppose to be the serum, and the lymph. The globules do not appear to be formed in those parts of the blood already produced, but rather to rise up in the surrounding parts.f It would also seem to be formed with more

* This will be more fully explained when on the colour of parts from the blood. f Thus, on some of the first appearance of the chick we find a zone surrounding it, composed of dots, which contain red globules, but not in vessels, and which zone becomes vascular afterwards.1 Vide Plate I. 1 [This account has been amply confirmed by Dcellinger and Wolff, who noticed the formation of blood globules, in the chick previously to the existence of either heart or vessels. Similar phenomena have also been related by Gruithuisen and Kaltenbrunner, who observed sanguineous pnncta to arise in inflamed and regenerating parts, which at first were placed in regular order, but afterwards united, so as to represent, and actually to constitute, new vessels, which in the further process of development formed interconnexions with each other, and with those which previously existed. (Tiedemann's Phys. trans, by Lane and Gully p. 150). Having already averted to M. Raspail's account of the origin of the red globules, I would here further observe that these bodies are probably formed much earlier in the process of sanguification (note, p. 68). MM. Prevost and Dumas detected globules in the chyle of rabbits, hedgehogs, and dogs, which they conceived might form the rudiments of the future blood globules ; for although the chyliferous globules have not all the same diameter, yet the largest among them are smaller than those of the blood, and consequently may admit of a further enlargement by the addition of their coloured envelopes. (Journ. des Prog, des Sci. Med.) Leuret and Lassaigne affirm that they have discovered fibrinous globules even in the chyme, in the stomach, and still more numerously in the duodenum, which globules they say exactly resembled those of the chyle, and ran together so as to form fibrils, precisely in the same manner as the globules of the blood. (Op. ut supra.) The striking analogy which exists between the chyle and the blood unquestionably must be allowed to be in favour of this opinion. If an animal be killed three or four hours after a full meal, and the chyle be collected, it will be found to exhibit an opake milk-white colour if the food has consisted of fat animal food, opaline if the diet has consisted of animal food without fat, and transparent if it has merely consisted of vegetables : after it has coagulated, the serum exhibits 72 HUNTER ON THE BLOOD. difficulty than either of the other two parts. When an animal has lost a considerable quantitv of its blood, the other parts seem to be sooner made up than the red globules ; the animal looks long pale; but this is only conjecture, for we have no method of knowing the quantity of the other parts. . From the above account it appears that whatever may be their utility in the machine, the red globules certainly are not of such universal use as the coagulating lymph, since they are not to be found in all animals, nor so early in those that have them ; nor are they pushed into the extreme arteries, where we must suppose the coagulating lymph reaches; neither do they appear to be so readily formed. This being the case, we must conclude them not to be the important part of the blood in contributing to growth, repair, etc. Their use would seem to be connected with strength, for the stronger the animal the more it has of the red globules; and the

the same general properties as the serum of the blood, and the coagulum consists of pure fibrin, of a slightly roseate hue. Still the composition of chyle and blood is not exactly the same; for, like the globules, the albumen and fibrin of chyle differ in some unimportant respects from those of blood, and appear, in short, to be in an incipient state, requiring some further elaboration (which is probably effected in the lungs) to render their conversion into blood complete. (Prout, Bridgewater Treatise, p. 520, and Ann. of Phil. xiii. 12.) The coagulum which forms from lymph collected from the thoracic duct of an animal which has fasted for several days, exhibits so deep a roseate hue as nearly to approach that of the blood ; and, like it, it is converted to scarlet by oxygen, and to purple by carbonic acid gas. (Magendie, Physiologie, 4e»ie edit.: Brux., p. 229.) I am not aware, however, that this fact has ever been observed of chyle collected in a pure state from thelacteals. Tiedemann and Gmehn have asserted that pure chyle has very little disposition to coagulate, and that it contains no globular or reddish particles previously to its having passed the mesenteric glands : but as these particles instantly appear after the chyle has passed this point, and particularly after it has become mixed with the lymphatic fluid proceeding from the spleen, they conceive it not improbable that the globules are formed in one or other of these organs. (Recherches sur la Digestion.) The opinion that the red globules are elaborated in the spleen is of very old date. It does not, however, appear to be well founded, for after the most accurate microscopical observations of the blood of a dog whose spleen had been removed several months previously, Dr. Babington was unable to discover any deficiency of red particles, as compared with the blood of another dog in perfect health whose blood was examined at the same time. (Med. Chir. Trans., xvi. 318.) The idea that they are formed in the mesenteric glands is rebutted, first, by the testimony of Leuret and Lassaigne, before mentioned; and, secondly, by the fact that many of the lacteals enter the thoracic duct without passing through the glands, and yet contain as many globular particles as those that do. Upon the whole, therefore, I am induced to believe that rudimentary globules are formed during the earlier periods of digestion, and that these are afterwards perfected in the system by means with which at present we are wholly unacquainted. This appears to me to accord better with the general law of progressive development which characterizes the whole organic world, than to suppose that they are perfectly formed at once by any individual organ. We see a gradually ascending scale of animated beings, a progressive formation of the different parts of each individual organism during the different periods of its growth, and a successive elaboration of its various proximate principles before they are applied to their hnal purposes in the economy. It seems, therefore, reasonable to suppose that the formation of the globules is governed by the same law]. GENERAL PRINCIPLES OF THE BLOOD. 73 strength acquired by exercise increases their proportion, not only in the whole body, but, as we shall find, occasions them to be carried into parts where, in either a quiet or debilitated state of the animal, they were not allowed to go; the use, therefore, of a part, and the quantity of red globules passing through it, are probably pretty well proportioned to each other. This effect is so well known to feeders of young animals for the table of the epicure, that bleeding, to lessen the quantity, is immediately practised ; as also debarring the creature from exercise, in order to prevent their increasing, and being carried so far from the heart as they otherwise would be. These three substances are of different specific gravities; the serum, or fluid part, is the lightest; the solid part, or lymph, is the next in order; and the red globules are the heaviest. This is seen in such blood as separates readily into its constituent parts. The serum swims upon the top, and the red globules fall to the bottom, while the lymph would be suspended between the two if the red part were not retained in the lymph, from its coagulation ; but this constant effect is no absolute proof of the difference in the specific gravities of the serum and coagulating lymph; for we still do not know but that the red globules, which are evidently the heaviest, make the coagulating lymph to sink in the serum. To ascertain this circumstance I made the following experiment: I took some blood, which separated easily into its constituent parts ; I then suspended in a portion of serum a piece of coagulating lymph, which was free from red globules, and it sunk to the bottom, but not very quickly : this proves that the lymph, when coagulated, is somewhat heavier than the serum. . . I then took as much of the bottom of the coagulum containing the red globules, and put it into the serum along with the lymph, to see which of them sunk the fastest, and found that the piece with the red globules sunk much more quickly than the other; I should think three times as fast. The serum itself is much heavier than common water, for when the parts before mentioned were put into common water, in the same manner as into the serum, they both sunk much faster, and there was not that disproportion between the times of their falling as in the serum. But if the blood has a strong disposition to coagulate, and is not in large quantity, it will coagulate soon, and involve the red globules; yet there will then be fewest at top, and they will be more and more crowded towards the bottom ; though there would appear in such blood to be no coagulating lymph at top free from the red globules, yet in most of it a "thin pellicle mav be found, which can be pulled off. I have already observed that the whole mass of blood, taken together, in a great variety of classes of animals, appear of a red colour; and I shall now further remark,that it is of a much deeper colour in some classes of animals than in others, which I believe arises from a greater number of red globules being contained in a given quantity of lymph and serum. This, I think, evidently appears to be the case when we examine a portion of the blood 74 HUNTER ON THE BLOOD.

itself belonging to different classes of animals. In the clas* ^ed quadruped I bdieve it has the deepest body of colour; 1 am not, however, certain that it is not nearly as deep in ^me birds , and even in the same class of animals it appears to have a much g*ater body of colour in some species than in others. Thus, it appears be deeper in the hare than in the rabbit. It is the red part itself which makes the difference in depth of colour in different parts of the animal; and the common mode ot judging is by the colour of the parts in different classes of animal, thaThave red blood; on these we generally form our opinion for though in some animals which have white muscles the liver, kidney, and heart, may be nearly as red as in others whose muscles are universally as red, yet, as the muscles are white, there must be a deficiency in the red globules on the whole; for if these parts which are red in animals having white muscles, as the heart, liver, etc., have no more than their due proportion with other animals that are universally red, there must be in such animals a deficiency of red globules on the whole. This idea may be gradually carried on, from the animal which has fewest red muscles, to those whose muscles are universally red and of a high colour; even in the same species the colour of all the muscles is not equally high. What are called different temperaments have their muscles redder or paler ; the darker the colour of the skin, hair, etc., of any one species, I believe the blood is in proportion redder. When a part, of whatever kind, is red, it takes place in consequence of its vessels being large enough to carry red blood; and therefore, when we find a muscle red we know it arises from the same cause. When a part, on the contrary, is white, as a tendon, it is because its vessels are small, and have little or none of the red blood passing along them, although it may probably be as vascular as the muscle to which it belongs;* and those animals that have no red blood have white flesh universally,! and this, probably, no less vascular than the flesh which receives red blood. The blood in the same animals is not equally deep-coloured in every part; that is, every part of the body has not its blood equally loaded with red globules, or, at least, it is not equally red, even in parts of the same construction and use, such as muscles; this arises from the red globules not being carried into those parts in equal proportion: these are the white parts of animals; such muscles,

* Conceiving that the amnion of a calf might have but few vessels, I injected a piece of it with quicksilver, first drying its edges all round on the edge of a dish, while the middle of it lay in the dish, in water; but the whole became one mass of vessels. The intention of this experiment was to see, if possible, the communication between the arteries and the veins ; but the mass of vessels prevented every view of this kind. ■j- The redness of the blood is of great use towards the knowledge of diseases; many inflammations are known by it when on the skin, and even the kind of inflammation is distinguished by the kind of redness: also putrid diseases are distinguished when the blood is extravasated. The quantity in the face is a sign of health or disease. GENERAL PRINCIPLES OF THE BLOOD. 75

in animals used for food, are called white meat. In animals which have these muscles there is commonly not so much red blood as in others where these parts are more universally red; and perhaps the red part of the blood is not pushed so far in them as in those which have it in a larger proportion. There are some animals, however, which have a larger quantity of red globules in the blood, yet have some of their muscles of a lighter colour than others : even in the human subject all the muscles are not equally red; the muscular part of the intestines, for instance, is not equal in redness to the heart, and many other muscles. To what is this owing! Does it arise from mechanical causes ? Do the vessels become suddenly so small beyond a certain limit as not to allow the red blood to pass? or are the other parts of the blood less tenacious > Is the red part in such not allowed to go so far 1 or is it a separating principle in the vessels themselves? Many circumstances in life either increase the quantity of the red globules, or make them more universal in the muscles of the same animal; thus, exercise increases the quantity of the red globules and ihe red colour of muscles, while there is the same quantity on the whole; or perhaps we should rather rather say that indolence decreases the quantity: this is particularly remarkable in woman; and probably the whiteness of the muscles of young animals may arise from the same cause; 1 suspect, however, something more ; I conceive it arises from the principle of life, influenced by accidental or mechanical causes, for the muscles of young animals are increasing in cobur till they arrive at the age of maturity, and not afterwards, although they continue to use exercise. Diseases lessen the quantity of the red globules, and often render their distribution unequal. ' From the above account we may reason, upon the whole, that the animals which are reddest, or have the greatest number of red parts, have their blood furnished with the greatest proportion of red

§ One^would naturally suppose that the red globules were of the same colour everywhere in the same animal; this last is perhaps the case: but now we find that these globules are of different hues in the different systems of vessels in the same animal. In the more perfect animals, where there are two systems of vessels carrying the blood, viz., arteries and veins, the blood is not of the same species of red in both of them in the same animal; one red is the

* [This mode of reasoning is extremely questionable. It ™7 ^J^^ example whether any decree of exercise would ever occasion the wing ""«!"» of ceS birds to as/ume-the dark tint which «h.™cten^ the musdejrf 4e legs, and e converse. According to Prevost and Dumas, birds are more vacular than mammiferous quadrupeds, and possess a greater «^'^.f1^' ^ vet there can be no doubt that the colour of their flesh is genera Uy paler ine same observation is equally applicable to the young of all animals. Bichat. has eXvoured toshow'that thecolour of muscles depends on some foreign substance ^mhined with their fibres; but this colour is certainly not essential to their SrfS rtrartare' for the lightest-coloured muscles are often those which are most contractile. (Bichat, Anat. Gen., ii. 327.)] 76 HUNTER ON THE BLOOD. scarlet, which takes place in the arteries of the body, the other is the modena, which takes place in the veins ; and as every part of the body possesses such systems of vessels, the parts which are visited by red blood must have a mixture of both. As there are two circulations in every animal above the insect, one in the lungs in those that breathe air, or in the gills, as in fish, in those that breathe water, and the other the general circulation to the body in both, we find the two colours of the globules not corresponding to the same system of vessels in each. The scarlet is the venal blood in the lungs, which afterwards becomes the arterial in the body, where it is commonly seen, and hence it is called the arterial blood: the modena is the venal blood of the body, and is the blood also of the pulmonary artery; but as it is commonly seen in the veins only of the b^dy, it is called the venal blood; the scarlet colour, therefore, is acquired in the lungs, and the modena in the body. There are so many proofs of this that it hardly requires any illustration; yet many circumstances and experiments may be brought in direct proef of it. I bled a man in the temporal artery and in the vein of the arm at the same time, each into a phial. The blood of the artery was of a florid red, and the venal was dark. The arterial kept its colour, and did not separate its serum ; but this was singular, for in others it does separate its serum and coagulum: the venal separated into its constituent parts as usual. Although this, however, is a general rule, yet there are many exceptions; for we find in many cases the scarlet colour of the blood in the arteries not changed in the veins, and under some circumstances the modena taking place in the arteries, as well as where blood is extravasated in the body.*

*[In ordinary bleeding it is not uncommon to find the blood which issues from the vein of a bright arterial tint; or sometimes the stream appears to be composed of dark and light-coloured blood in nearly equal proportions, as if the artery and vein had both been punctured. This is particularly observable in excited states of the circulation, when at the same time the function of respiration is carried on without impediment. Baglivi noticed this appearance of the blood in bleeding patients who were labouring under hectic fever; but it is certainly much more frequent in rheumatic attacks and after brisk exercise. Sometimes this appearance is produced by the warm bath (Thackrah, p. 181), and in a less degree by warm climates; sometimes by fits, paroxysms of palpitation and syncope, and not unfrequently by common inflammation and fever. Broughton found the blood in the veins of animals which had been made to respire oxygen gas as florid as in the arteries. Thackrah remarked that a similar effect was generally produced by a full dose of prussic acid. It would seem, therefore, eitherlhat the blood is unduly oxygenized in the lungs, or else that it is hurried through the circulation with too great rapidity to allow it to undergo the usual changes in the periphery of the body. The peripheral and pulmonary circulations being antagonized to each other, either of these causes may produce the effect by destroying the balance which necessarily subsists between thern in a normal state: besides which, it is extremely probable that this balance may sometimes be disturbed through the mere influence of the nervous system, independently of any alteration in "the physical conditions under which the vital functions are performed. Thus, Dupuytren found that the blood was only imperfectly arterialized in the lungs when the eighth pair of nerves was divided; and, as the counterpart of this fact, it is noto- GENERAL PRINCIPLES OF THE BLOOD. 77 It becomes a question how the change is produced in each. More attention has been paid to the mode in which it gets the scarlet colour than the modena (though both probably are of equal

rious that the blood is not venalized in inflamed parts. There is no improbability, therefore, in supposing that the whole function of nutrition may be more or less partially suspended for a time, in consequence of which the blood may pass through the capillaries of the body without undergoing any change, or at least any change commensurate with the effect produced in the lungs. It more frequently happens, however, that the blood is black in the arteries than red in the veins ; this appearance depending on the reverse of those causes which have been above-mentioned. Thus, during the congestive stage of fevers the blood exhibits a black appearance arising from the remora of the circulation. The same thing also happens in cholera, apoplexy, epilepsy, poisoning from opium, and under a variety of other circumstances where the respiration is impeded or the circulation materially retarded. The principal points of difference which distinguished arterial from venous blood are comprehended in the following table : Arterial. Venons. Specific gravity (Davy, Phil. Trans. 1814.) .... 1051 1049 Capacity for heat (lb.)........... 913 903 Temperature . (lb.)...........1° more. 1° less. Carbon . . . ^ r 50-2 55-7 Oxygen. . . I /7I, . .. „, ., Ann. J 26-3 21-7 Nitrogen . . \ (Macatre & Marcet, op.ctt.ipA00) ^ lfi.3 16.2 Hydrogen . . J ^ 6-6 6-4 Electricity . (Bellingeri, Exper. in Elect. Sang.) . less. more. p , ( bright ( brownish or .......'.......\ scarlet. \ modena red. Odour . . . (Magendie, Physiologic)......strong. faint. Coagulation . (Thackrah.).........quicker. slower. Clot to serum (lb.)...........more. less. Fibrin . . . (Alison, Physiology.)......more. less. r, , ., ,c. .,, $ appreciable Carbonic acid . (Stevens, op. cit.).......none. < Quantities S great sup- ( weak supporter of < porter of Hfe. f life.

Besides these differences, there are probably some others, arising from the different degrees of vitality possessed by the two bloods ; but these can only be investigated in their effects upon the solids. In connexion with this subject it may not be improper to advert to the diversities of the blood in different vessels of the same body. Thackrah found that the portal blood of dogs differed from blood from the jugular veins in containing much less albumen and haematosine, in coagulating more rapidly, in having a muddy-brownish colour, as if it had been defectively elaborated, and in some other minor particulars. (Op. cit., p. 70.) Stoker made similar observations. (Op. cit., Part ii., p. 31.) Now it must be manifest that these remarks are only applicable to blood from different parts of the venous system. In the arteries it must be the same everywhere ; but in the veins it must be continually liable to variation, in consequence of the obstructions which are made by the different secretory organs. (See M. Le Gallois'Essay entitled " Le Sang est-el identique dans tous les vaisseaux qu'ilparcourt.?" Par. An. xi.) Allied also to this subject is the alteration which the blood undergoes in regard to its chemical constitution during one and the same venesection. This point has been already adverted to in reference to the diminution of fibrin (see note, p. 44) ; but it remains to be noticed that the quantity of serum is proportionally increased under the same circumstances, probably because the absorbent system 78 HUNTER ON THE BLOOD. importance), because it was believed that life in some degree depended on this colour. Many substances change the colour ot the

is roused to increased action by whatever depresses the vital P™er_s jf/™" cologia, by J. A. Paris, M.D., 5th edit., p. 174), or else because the first evacuation of blood causes the return into the larger vessels of much of the thinner parts of this fluid previously divergent in the invisible capillaries, buch at least are the opinions of Davy (De San?., 1814) and Schrceder Van der Kolk (Com. de Sann.Coag., 1820, 1. c.), and the same views have more recently been adopted by Dr. Alison, (Physiology, p. 58.) The attenuation of the blood in these cases has been assigned as the cause why it coagulates more rapidly the nearer an animal approaches to the state of syncope. Prater found that blood which was diluted with equal parts of water coagulated only one minute sooner than a similar quantity not diluted, but that dilution with one-half, one-third, one-sixth, or even one-tenth of serum accelerated concretion at least six minutes ; from which facts he argued " that dilution takes place by a provision of naj"™- and that such dilution is the principal if not the sole cause why the blood flowing from a dying animal coagulates so quickly." (Op. cit., pp. 109, 111, 114.) -Now it is not to be disputed that repeated venesections, at considerable intervals of time, will have the effect of increasing the tenuity of the blood (see note, p. 50); but it is extremely doubtful whether this effect is uniformly or even generally produced during a single venesection, however copious. Thackrah did not find this to be the case, but, on the contrary, that the fluid parts of the blood were often diminished in the last cup. The same thing also occurred to Prater, whose experiments, however, are open to many sources of fallacy ; and, even though we should admit the fact, yet it would not explain all the circumstances of the case, for timidity and alarm not unfrequently occasion the first portions of blood to coagulate more rapdly than the last, while of three portions of blood taken from a slaughtered animal, the third is often observed to be slower in coagulating than the second : besides, " Pithing, poisoning by prussic acid, and the injection of air into the veins, show as strongly as death from hemorrhage the last-drawn blood to concrete with greatest rapidity." (Thackrah, p. 139.) 1 conceive, therefore, that these differences in the coagulating power of the blood may best be referred to the varying conditions of the vital powers. The following Table exhibits the differences of time in regard to the blood's concretion: 1st Cup. 2d Cup. From a dog bled to death From a slaughtered sheep Ditto...... Ditto...... From a slaughtered ox Ditto...... Ditto...... Ditto...... Ditto...... From a stuck horse 10 30 10 10 40 29 50 30 30 11 10 0 40 1 00 0 50 1 45 6 45 8 30 1 10 1 35 0 50 9 55 3d Cup. 0 30 0 55 0 55 0 30 2 15 1 10 0 20 3 20 Accordingly, Thackrah found that in venesection syncope reduced the time required for concretion from 5' to 2,' or from 90" to40". (Op. cit., p. 132.) Blood taken during the actual state of syncope rarely separates its serum, and in proportion as an animal approaches to this state, the separative change is less and less; thii6, from a stuck calf the first portion of blood (which was taken on the infliction of the wound), yielded 4123 serum to 5877 crassamentum, while in the second portion (which was taken when the hemorrhage had nearly ceased) the proportions were as 3617 to 630*3.] } h GENERAL PRINCIPLES OF THE BLOOD. 79 blood from the modena to the scarlet; respirable air has this effect, and many of the neutral salts, more especially nitre, which occasions the florid colour in meat that has been salted also with seasalt. But as the air produces this effect in the living body, and as we find that without air the animal dies, great stress has been laid on this change of colour, whereas it should only be considered as a sign that the blood has been in contact with the air, but not that it must be fit for the purpose of circulation. This effect takes place readily under many circumstances; it takes place out of the circulation as readily as when in it; as readily when blood is coagulated as before; it takes place in blood whose coagulating principle has been destroyed, as by lightning, sudden death, &c.: it does not, therefore, depend upon life. It is the cause only of this change in the colour by respirable air which becomes an object of consideration; for if we suppose the change of colour in the red globules to be all that respiration is to perform, we shall make the red globules the most essential part of the blood, whereas they are the least so. Most probably the effect of air upon the blood is greatest on the coagulating lymph; and this conjecture is rendered more likely when we consider that in animals which have no red globules of a ny kind respiration is as essential to their existence as in any other, and we find that the blood may lose this effect and yet retain its salutary effects in the constitution. Thus, when any large artery is tied, the parts beyond must be supplied with blood that shall have lost its florid colour; and in the chick in the egg the blood in the arterial system is dark, while in the veins of the temporary lungs it is florid. We are led by daily experience to observe that the dark blood taken from a vein becomes red on that surface which is exposed to the common atmosphere, and that if it be shaken in a phial with air the whole becomes red.# If blood also be allowed to stand exposed to the air and to coagulate, its upper surface will become of the scarlet-red, while the bottom remains dark, or even of a darker colour than common venal blood, because it contains a greater quantity of red globules. If the coagulated blood be inverted, and the bottom exposed to the air, this part will also assume the scarlet-red, and become even redder than that exposed before, because it contains a greater number of red globules, which undergo this change. The red colour will even penetrate to some depth, which shows that the effect can be produced through a thick substance. We often find the vessels of the lungs full of blood, and the whole substance of the lungs of a dark colour; but if we inflate the lungs the cells will become of a florid red, the small vessels on those cells, both arteries and veins, having the colour of their blood changed by the air in the cells affecting it through their coats. We find the same thing on the surface of flesh or muscles, liver, &c. We may observe in the gills of fish that they retain their florid colour as long as the fish is fresh, from

* This does not arise from motion, for fill the phial with blood without air, and put into it glass-beads, and shake them, so as to give it motion, the colour will not be altered. 80 HUNTER ON THE BLOOD. being exposed to the air, for they naturally have the air applied externally in the act of breathing. It is from these facts we reason respecting the scarlet colour which the blood acquires in the lungs but loses in the body, and why, therefore, it is found of the modena colour in the veins, and of course in the right side of the heart and larger trunks of the pulmonary artery. As the blood is florid in the pulmonary veins as far as we can trace them, we reasonably suppose that it acquires this appearance in the small vessels of the lungs, and as the lungs constantly take in fresh air, we conceive that by exposure to the air (perhaps both in arteries and veins) it acquired the scarlet colour; for we shall see that the air, or the influence of the air, is capable of passing through animal substance. In the living body, when the breathing is imperfect, we can plainly see the change taking place in the colour of the blood in proportion as the breathing becomes more perfect, of which the following experiments are proofs. They were made with a view to observe the motion of the heart, by producing an artificial breathing and exhibited a vast variety of satisfactory phenomena, of which the change in the colour of the blood in the lungs was one. I invented a pair of double bellows, each of which had two openings, but their actions were reversed : two of the openings were inclosed in one pipe or nozzle, and the other two were on the sides. The lower chamber had its valve placed exactly similar to that of the common bellows; but it had also a valve at the nozzle, which did not allow any air to enter there. The upper half had a valve placed at the nozzle, which allowed the air to enter but not to escape, and the opening on the upper side allowed the air to escape but not to enter; so that, on dilating the bellows, the upper side or chamber drew in the air by the nozzle only, and at the same time the under chamber drew in its air by the side only. On closing the bellows, or expelling t his air, the air drawn in by the nozzle passed out at the opening on the upper side, and the air that was drawn in by the under side passed out by the nozzle. By this means I could, by fixing the nozzle into the trachea, draw the air out of the lungs into the upper chamber of the bellows, and at the same time draw fresh air into the lower chamber; on emptying these cavities of their air the pure air in the lower chamber passed into the lungs, and that which had been just taken from the lungs into the upper chamber passed into the open air alternately. The action of these bellows, though double, is exactly as simple as breathing itself; and they appear to me to be superior to any invention made since for the same purpose.* I fixed the nozzle of these bellows into the trachea of a dog,

* [The principal inconvenience of this bellows consists in the extreme difficulty of regulating the artificial respiration. The researches of Magendie and Leroy have fully established the fact of the great liability of the air-cells to become ruptured when the quantity of air impelled is either too great or too rapidly affected, in consequence of which the pulmonary tissue is rendered emphysematous, and the chances of recovery much diminished ; and to so great a degree are the lungs exposed to this danger, that it has even been doubted whether the proportion GENERAL PRINCIPLES OF THE BLOOD. 81 and immediately began the artificial breathing. I then removed the sternum and cartilages, and opened the pericardium. While I continued the artificial breathing, I observed that the blood in the pulmonary veins, coming from the lungs, the left auricle, the aorta, &c, was florid or dark just as I threw air into the lungs. I cut off a piece of the lungs, and found that the colour of the blood which came from the wound corresponded with the above effects. When I threw air into the lungs, so as to render the blood florid in the pulmonary veins, two kinds of blood issued from the wound; and when I left off blowing, the whole blood which passed out by the wound was of the dark colour. If the air is confined in the luno-s of a quadruped, it soon loses its power over the blood, which Remains dark, or has the appearance of becoming dark, because dark-coloured blood is thrown in and it undergoes no change ; but if the same experiment is made on an amphibious animal it is a considerable time before the whole blood becomes dark, because in such animals the lungs are a reservoir of air, which of course continues its influence over the blood for a longer time. This experiment I have repeated upon several animals, and commonly for half an hour at a time, which was sufficient to allow me to make my observations with coolness and accuracy. In this part of the experiment it was curious to see the coronary arteries turn darker and darker, becoming like the veins which run on each side of them, and on blowing again resume gradually a brighter colour, till they became of a florid red. As respiration was generally prevented in the first part of the experiment, the blood was found at first wholly of a dark colour, and the heart large and hardly acting; but on throwing into the lungs fresh air, the heart began to act, upon which both auricles and ventricles became gradually smaller; then by stopping the respiration they again became larger and larger. . . . The diminution of the heart's motion upon stopping respiration does not depend upon the immediate impression of improper blood on the left auricle and ventricle as a sedative, but upon the sympathetic connexion which exists between the heart and lungs (one action ceasing the other also ceases) ; which sympathy is established, because if the heart were to continue acting it would send improper blood into the body, by which it can be supported only a little while. The right auricle and ventricle also cease acting, although not so early, and for the same reason; because on the

of recoveries from asphyxia has not been considerably reduced since the introduction of this means of resuscitation. ♦„♦:„„ „e To obviate this inconvenience, M. Leroy has recommended the adaptation ot an arc of degrees to the handles of Hunter's bellows, graduated in such a manner as at once to show the proportions requisite for the different ages of life, to which are added moveable pipes to correspond, so as only to allow of the escape of the air in such ouantities and in such periods of time as shall closely represent natural resoiration. There can be no doubt that this is a very great improvement upon the old bellows, and ought universally to be adopted in all institutions for the recovery of drowned persons. (Magendie's Journ. de Phys., vn. vm. xi.)J 8 ft2 HUNTER ON THE BLOOD. cessation of the function of the lungs the blood cannot receive any benefit in passing through them. These actions and cessations are all dependent on life and the connexion of one action with another. It is upon the same principle that the first effect of recovery is the act of breathing.* The following cases illustrate this still further. I bled a gentleman in the temporal artery, while in a fit of apoplexy; he breathed seemingly with great difficulty; the blood flowed very freely, and he continued to bleed longer than we commonly find'from the same wound, which made me suspect that the artery had lost some of its contracting power. The blood was as dark as venal blood ; he became somewhat relieved, and his breathing more free. About two hours afterwards we opened the same

* [The cessation of the heart's action, in cases of asphyxia, would appear to depend, 1st, On the circulation of black blood through its substance, by which its irritability is more or less impaired ; 2d, On the effects of black blood on the brain producing universal depression,— lowering still further the tone of the heart, and paralysing the muscles of respiration, as well as the pulmonary capillaries; 3d, On the insufficient supply of blood which is sent to the left side of the heart in consequence of the paralysis of the pulmonary capillaries. We may therefore trace a sort of reaction in a circle among the vital organs, each concurring towards the same effect. What is the exact order of their cessation, or the precise share which each of them has in producing the ultimate effect, is not easily assigned. In syncope the series of phenomena would appear to commence with an impression on the brain, which is propagated to the heart, and thence to the lungs; but in asphyxia the first effect is probably felt by the heart, the second by the brain, and the third by the lungs. Goodwyn conceived that the heart ceased to act because the left side, being only arterio-contractile, was incapable of being stimulated by venous blood; but this idea was fully disproved by the experiments of Bichat, which render it certain that the blood stimulates the ventricles not by its quality, but by its bulk. (Goodwyn on the Connex. of Life with Resp. pp. 82, 83; and Bichat, Sur la Vie et la Mart.) On the other hand, Bichat's theory that the heart is poisoned by its own blood, is disproved, first, by the experiments of Kay and Edwards, which tend to prove that venous blood contributes, although feebly, to support muscular irritability; secondly, by the post mortem appearances, which exhibit the right side of the heart and the whole venous system gorged with blood, while the left side is almost wholly empty, contrary to what might be expected, considering that the left ventricle ceases to act first in ordinary death ; and thirdly, by the difficulty of accounting for the renewal of the contractions of the heart on the reestablishment of respiration. Resuscitation from asphyxia would, if Bichat'a doctrine were true, be impossible, because the very power by which it must owe the restoration of its irritability would be destroyed; whereas by admitting that the heart retains a certain portion of irritability, it is not difficult to account for the renewal of its contraction as soon as the stagnation in the pulmonary capillaries is removed. It would obviously be inconsistent with the object of these notes to enter en this subject mote fully; at the same time it appeared necessary to guard the reader against the notion, that " these actions, or cessations of actions, are all dependent on life" abstractedly considered. The fact is, all the phenomena of asphyxia primarily arise out of the interruptions to those chemical changes which atmospheric air produces on the blood, in consequence of which venous blood is circulated through the system, and produces a series of effects which are plainly capable of being analytically examined. (See Cyclop, of Pract. Med., art. Asphyxia, by Dr. Rojet.) ] GENERAL PRINCIPLES OF THE BLOOD 83 orifice, which still bled freely, but now the blood was become florid as usual. Mrs.----, in Norn's street, Haymarket, fell into an apoplectic fit, in which she was insensible respecting ideas: her breathing was very imperfect, attended with a rattling in her throat, and a snort; the pulse was very steady, but rather slow. I opened the temporal artery, which bled very freely. But I observed that when she breathed freely the blood from the artery became red ; and when her breathing was difficult, or when she hardly breathed at all, the blood became dark, and this alternated several times in the course of bleeding; yet all this made but little alteration in the pulse. In many diseases of the heart, as well as of the lungs, we may often observe the same appearance. In many diseases of the heart, producing what is called angina pectoris, (the symptoms of which arise from a vast variety of causes, palpitations being commonly one,) we shall see that upon any exertion the heart acts with great violence, and the breathing is very laborious, or rather imperfect, not corresponding with the violence of the motion of the blood ; the face will become of a dark purple colour, the patients will be nearly expiring, and nothing but rest relieves them. Of this the following case is a strong instance. A. B. when a boy could never use the same exercise that other boys did; he could not run up stairs nor ascend a hill without being out of breath, and had almost through his whole life an irregular pulse, more especially when he used more exercise than he could well bear. Upon the least increase of motion he had a palpitation at the heart, which was often so strong as to be heard by those that were near to him; and his becoming soon fatigued was by his acquaintances supposed to be owing to a want of spirit or courage. With all this he grew to be a well-formed and commonsized man; but still he retained those defects, which indeed rather increased as he extended his views, and with them extended his actions. About the age of thirty he took to violent exercise, such as hunting, and often in the chase would be seized so ill with palpitations and almost a total suffocation that he was obliged to stop his horse and be held upon the saddle. At such times he became black in the face, and continued so as long as the fit lasted. It was often several days before he perfectly recovered his usual health, and frequently he could not lie down in his bed, but was obliged to sit up for breath. All these symptoms gradually increased upon him, and at times, without any violence of exercise or action, he would feel as if dying, and used so to express himself; but as the cause of these feelings did not appear to his friends, they rather treated them slightly. At last mere anxiety of mind would bring on these feelings, palpitations, and suffocations in some degree. In the winter 1780 and 1781 he hunted very violently and also caught cold, which together brought on the above-mentioned complaints with greater violence than ever. He consulted two gentlemen of the profession : the palpitation, the difficulty of breathing, 84 HUNTER ON THE BLOOD. the great oppression, with the blackness in the face (I SUPP°^C)th^ thought either arose from spasms, or was nervous, lor they oraerea cordials, such as spirit of lavender, wine, &c. •„„„:,:„„ I was sent for, to give a name to the disease. Upon inquiring into all the symptoms, my opinion was that there was something very wrong about the construction of the heart via., about the source of the circulation ; that the blood did not flow at any time freely through the lungs, so as to have the proper influence ot the air, but much less so when he was hurried ; that a stagnation of the blood in any one part about the heart would produce in some degree suffocation, and want of due influence of the air upon the blood (being the same thing), which was the cause of the darkness of the face at those times ; that the means to be practised were in some degree contrary to what had been advised, viz., rest, gentle bleeding, care to eat moderately, to keep the body open, and the mind easy : and as he had got the better of former attacks (although those were not so violent), I saw no absolute reason why he should not get the better of the present. Eight ounces of blood were taken from him that day, which relieved him. The symptoms still continuing,though not so violently,I saw him once more; he lost about four or five ounces more blood, which also relieved him, but still he did not get materially better. At last, in addition to the above symptoms, he became yellow, his legs began to swell with water, and all his other complaints gradually increased, which made me suspect that a deposit of water was begun in the chest. He was now attended by a physician ; was blistered on his legs, which threatened a mortification, and a caustic was applied to the pit of his stomach (I suppose for a pain there): nature was at last worn out, and he died. I solicited to open him, and was allowed. On opening the belly there was found in the abdomen a very small quantity of bloody, yellowish serum. Every viscus appeared to be sound; the gall-bladder was pretty full of bile, which was thick, but not ropy, as if the thinner parts had been strained off; the ducts were clear, both to and from the gall-bladder. Upon opening the chest the lungs did not collapse, being a good deal cedematous, but otherwise appearing sound; there was also a little bloody serum in both sides of the chest: these I conceive were the consequences of the last attack. The heart was very large, and very full of blood. Upon opening the right side of the heart, I found nothing uncommon either in the heart or the pulmonary artery. Upon opening the left side, I found the valves of the aorta thicker and harder than usual, having at the same time the appearance of being very much shrivelled. This diseased structure of the valves accounts for every one of what may be called his original symptoms, and was such as to render them of very little use; the blood, therefore, must have fallen back into the cavity of the ventricle again at every systole of the artery. Whether this shrivelled state of the valves of the aorta was a natural formation, or a disease, is not easily ascertained; but if it GENERAL PRINCIPLES OF THE BLOOD. 85 was a disease, it must have begun much earlier in life than such diseases commonly do, as the symptoms appeared when he was young.* From this construction of valve we must see that it required the greatest quiet to allow the motions of the blood from the left side of the heart to go on sufficiently, and that whatever interrupted this produced a stagnation, or an accumulation of the blood almost in every part of the body ; first, in the left ventricle, then the left auricle ; pulmonary veins, pulmonary arteries; right ventricle, right auricle, and all the veins in the body: however, a smaller quantity than usual could get to the veins of the body through the arteries, so that a kind of circulation went on. If we consider the effect arising from this construction of valves simply on mechanical principles, we cannot account for the darkness of the arterial blood, which must have passed through the lungs when there was no mechanical obstruction to respiration ; but since it happens that when the heart either ceases to act, or cannot get rid of its blood (which must have been the case in the present instance), respiration ceases, or is performed so imperfectly as to have nearly the same eflect,f the person is in reality in a state of suffocation. Suffocation is no more than imperfect respiration, which is the cause of imperfect blood passing to and from the left side of the heart; and it is therefore immaterial, as to consequences, whether a stoppage to respiration is the first cause, or is an effect, for in either way it is the cause of imperfect blood being introduced into the arterial system. It may be difficult to account for the increased size of the heart; whether it was a mechanical effect, as the blood would be thrown back into it at every systole of the aorta and diastole of the heart, or whether it arose from a particular affection of that viscus. The first idea is the more natural; but it is not necessary that the cause should be of this kind, for we see every day enlarged hearts, where the symptoms have been somewhat similar, and yet no visible mechanical cause existed; and indeed it is a common effect where there is an impeded circulation. It is easy to be conceived, first, that the circulation could not, in the case of this patient, be carried on regularly and perfectly; secondly, that a stoppage to the blood's motion in either arteries or veins, but much more a retrograde motion of the blood in any part, must produce a stagnation, which will be more or less extensive, according to the quantity of blood passing that way; thirdly, that if it was only in a branch of an artery, or vein, the stagnation would probably be only partial; but when in an artery, or the veins of the whole body, as the aorta or vena cava, it must then be pretty universal; and as the retrograde motion in the blood began in the aorta, we can easily trace its effects. We also find, in imperfect

* I have seen it at a very early period. f In such inspirations I conceive that so little air is taken in as hardly to reach the cells of the lungs, so as to be able to influence the blood circulating on those cells. 8* 86 HUNTER ON THE BLOOD. constructions of the heart, etc., where there is a communication between the right and left side, kept up after birth, that the same circumstances and apearances take place; cases of this kind frequently occur, of which the following is a strong instance. I was several times consulted about the state of a young gentleman's health, and though it could not be said anatomically, with precision, what the real conformation of the heart was, yet it was imagined that the svmptoms arose from some imperfection in that organ. From his infancy, every considerable exertion produced a seeming tendency to suffocation ; and as suffocation always arises from a want of the due effect of air on the blood, while the circulation is going on, the whole body must change from the scarlet tinge to the modena or purple; and in those parts where the blood gives its colour most, there will this effect be greatest, which is commonly in the face, and particular parts of the face, at the finger-ends, etc. While very young nothing but crying brought on those fits, but when he was grown so as to take bodily exercise, as running, etc., then they became more frequent and more violent; and it is to be observed, that the older he grew the worse he was likely to be; for, with years approaching to maturity, his actions were likely to increase: great care, however, was taken to suppress such actions as were found from experience to bring on the fits. No medical advice could be of the least service, further than to inform him what experience had already taught, unless to recommend occasionally, when his friends found that the fits of suffocation were more easily excited than usual, that he should lose a little blood, so as to lessen the necessary action of breathing; putting, in this way, the quantity and motion of the blood more upon a par, and at the same time not to indulge too much his appetite; but all these precautions hardly kept him tolerably well. The heart, in proportion to the difficulty, acted with more violence; and one could rather have wished the contrary to have taken place. As he could hardly use any exercise of his own, motion was given him, such as riding slowly on horseback, in carriages, etc. He lived to the age of between thirteen and fourteen ; and though the disorder did not destroy him, yet it is most probable that he could not have lived long, as he was every day arriving more and more at an age of action, but not in the same proportion acquiring prudence. When he died he was opened by Dr. Poultney, who transmitted an account of the appearance of the parts to the College of Physicians of London, which is published in the third volume of their Medical Transactions: such parts as are immediately connected with my subject I shall transcribe. " Both lobes of the lungs were remarkably small, and some parts of them flaccid to such a degree as to suggest an idea of their having been incapable of performing their functions.* The liquor pericardii was in due quantity, and the heart was firm in texture, and of the

* Although I have transcribed this, yet I do not lay much stress upon it. GENERAL PRINCIPLES OF THE BLOOD. 87

natural size.* On examining the ventricles and the beginning of the aorta, a canal, or passage, was found communicating with both ventricles, situated in an oblique direction near the basis of the heart, so large as to admit the end of the finger from the aorta with equal facility into either ventricle, the septum of the ventricle appearing to terminate with this canal. On examining the entrance of the pulmonary artery within the ventricle, it was judged that this entrance was much smaller, and more firm than common." It is difficult here to say what would be the exact effect of this communication on the motion of the two bloods; that is, whether the blood of the right side was received into the left, or vice versa; if the oblique direction of this passage had been further described, it might have explained this doubt; for if the passage was direct, the blood would most probably pass from the left to the right, as the left ventricle acquires the greatest strength: the word oblique, however, and the expression, that the finger, from the aorta, passed with equal facility into either ventricle, would make us suppose that the obliquity led out of the right ventricle into the aorta; but,even with this obliquity, I should not think it probable that the blood would pass from the right to the left, because the left acts with so much more force: the description leaves us to account for the defect in respiration another way. If the blood passed from the right to the left, then it would have had the same effect as the canalis arteriosus, and probably was the only one in the foetus. In this case too little blood would pass through the lungs; but I do not conceive that this circumstance would affect respiration, because no stagnation would take place in the lungs; but if the blood got from the left to the right, then too much blood would be sent to the lungs, as it would be found to take its course twice. On the other hand, if the lungs be not capable of allowing a full distension equal to the actions of the heart, though naturally framed, the same thing takes place. In natural deaths the pulsation of the heart commonly stops before breathing ceases ; but in deaths arising from a stoppage of breath, such as hanging or drowning, the reverse must take place; and in such we shall always find dark blood in the left side, which plainly took place in the experiment abovementioned. It may be supposed that in the lungs the blood cannot come in contact with the air ; but the circumstances above related, that the florid colour will extend some depths into the blood, shows that the effect of air can and does pervade animal matter. Not attending to this fact at first, I covered the mouths of vessels filled with venal blood with gold-beaters' skin, touching the surface of the blood, and the blood constantly became of a florid red on the surface, and even for some depth. I put some dark venal blood into a phial, till it was about half * This shows there was no disease. 88 HUNTER ON THE BLOOD. full, and shook the blood, which mixed with the air in this motion, and it became immediately of a florid red.* As the globules are the coarsest part of the blood, and they appear to be fully affected by the air in the lungs, we may suppose that the vessels of that viscus do not run into extreme minuteness, by which, apparently, no other purpose would be answered. The blood of the menses, when it comes down to the mouth of the vagina, is as dark as venal blood ; and as it does not coagulate, it has exactly the appearance of the blood in those where the blood continues fluid. Whether this arises from its being venal blood, or from its acquiring that colour after extravasation, by its slow motion, it is not easily determined; but upon being exposed it becomes florid; it is naturally of a dark colour, but rather muddy, not having that transparency which pure blood has. Whether this arises from its mixing with the mucus of the vagina, or from the cessation of life in it, I will not pretend to say. The red globules, however, are not dissolved ; they retain their figure. Does air in the cellular membrane of an emphysematous person produce or continue the floridness of the blood or not?f The surface of the blood becoming of a scarlet-red, whether exposed immediately to the air, or when only covered by membranes, through which we may suppose its influence to pass, is a circumstance which leads us to suppose that it is the pure air which has this effect, and not simply an exposed surface.J To ascertain this, I made the following experiment: I took a phial, and fixed a stop-cock to its mouth, and then applying an air-pump to the cock,exhausted the whole air: in this state, keeping it stopped, I immersed its mouth in fresh blood flowing from a vein, and then turning the cock, allowed the blood to be pressed up into the phial. When it was about half full I turned the cock back, and now shook the phial with the blood, but its colour did not alter as in the former experiments; and when 1 allowed the blood to stand in this vacuum, its exposed surface was not in the least changed.§ The vast number of cells into which the lungs are divided, the whole arterial and venal system ramifying on the surface of those cells, and of course the whole of the blood passing through them in every circulation, together with the loss of life upon the missing three or four breathings in the most perfect animals, show the great nicety that is required in preserving the due properties of the

* These experiments I made in the summer 1755, when 1 was house-surgeon at St. George's Hospital, and Dr. Hunter taught them ever after at his lectures. t Vide Chester on Cases. Case first, the venal florid. St. George's, a man emphysematous; blood very dark. | I may here observe, that fixed air [carbonic acid gas], as also inflammable airs, have contrary effects. § [I have much pleasure in referring the reader to Faust and Mitchell's papers on Endosmose and Exosmose, and on the Penetrativeness of Fluids, in the American Journal of the Medical Sciences, vol. vii., pp. 22, 36. See also note, p. 42, respecting the menses.] GENERAL PRINCIPLES OF THE BLOOD. 89 blood for the purposes of animal life: the time that we can live without air, or breathing, is shorter than that in which we die from a defect in any other natural operation ; breathing, therefore, seems to render life to the blood, and the blood continues it in every part of the body. This nicety is not nearly so great in many of the more imperfect animals. The amphibia have not this division of lungs, nor does the whole of the blood pass through the lungs in them, and they can live a considerable time without breathing. This, at present, I only mention as a fact, not meaning to give my opinion of the mode of preserving life, either in the blood or body, by the application of air to it; though I will say that mere life in both is supported by the air, and probably few of the other properties connected with the blood depend so much upon air as its life. But we may observe, that it was not necessary for the blood to undergo this change to render it fit for every purpose in the animal economy, for we find that venal blood answers some purposes: thus, the blood from the intestines, spleen, etc., going to the liver, as we suppose for the secretion of the bile, shows that venal blood will do for some secretions, though probably not absolutely necessary.* This application of venal blood is a saving of blood ; and it is not necessary for the formation of bile that the venous blood should proceed from the parts above-mentioned, for in birds, amphibia, etc., other veins, besides those, enter the liver. I have shown that several substances mixed with dark-coloured blood have the property of rendering it of a florid red ; and it must have appeared that by circulating through its body its dark colour is restored. As it is capable of being rendered florid by several substances, so it may be rendered dark by several when florid: vital air [oxygen gas] has the power of rendering it florid; but the other vapours, or gases, which have the name of airs, such as fixed air, inflammable air, etc., render it dark. This change is peculiar to the living body, for if arterial blood is taken away, it retains its florid colour, although not in the least exposed to the air.f As it is found dark in the veins, and as it performs some offices in the course of the circulation which perhaps render it unfit for the pur-

* [This question was for a long while agitated, many physiologists contending that the blood acquired in its passage through the spleen, omentum, intestines, &c., peculiar qualities which fitted it for the secretion of the bile. However this may be, it certainly is not indispensable. The trunk of the vena porta? has been found in several instances to terminate in the inferior cava, instead of branching out into the liver. Mr. Abernethy found this in a child about ten months old (Phil. Trans., 1793, p. 59), and Mr. Wilson in a young female (Med. Gaz., viii. 443), the gall-bladder in both cases being perfectly full; and in the last case the hepatic artery increased to a great size. Saunders, Huber, and Lawrence have referred to similar cases.] f [Arterial blood is rendered dark by being placed in the vacuum of an air pump. There appears, therefore, no good reason for believing that any of the effects, relating to change of colour, which take place in the lungs, are peculiar to the living body.] 90 HUNTER ON THE BLOOD. poses of life, we may conceive that the loss of colour and this unfitness are effects of the same cause: but, upon further observations on this fluid, it will be found that it may be rendered unfit for the purposes of life wiihout losing its colour, and may lose its colour without being rendered unfit for lifer slowness of motion in the blood of the veins is one circumstance that causes the alteration; but this alone will not produce the effect, for I have observed above, that arterial blood put into a phial, and allowed to stand quiet, does not become dark; but rest, or slowness of motion in living parts, would appear, from many observations, to be a cause of this change in its colour. We know that the blood begins to move more and more slowlv in the arteries; we know that its motion in the veins is slow in comparison to what it is in the arteries; we should therefore naturally suppose (considering this alone), that it was the slowness of the motion that was the immediate cause. Rest or slowness of motion, in living and probably healthy parts, certainly allows the blood to change its colour; thus, we never see extravasations of blood but they are always dark. I never saw a person die of an apoplexy, from extravasation in the brain, but the extravasated blood was dark ; even in aneurism it becomes dark in the aneurismal sac ; also when the blood escapes out of the artery, and coagulates in the cellular membrane, we find the same appearance. These observations respecting apoplexy struck me much. I conceived at first that the extravasations there must consist of venal blood; but, from reasoning, I could hardly allow myself to think so; for whatever might be the beginning of the disease, it was impossible it could continue afterwards wholly venal, especially when the blood was found in a considerable quantity; because, in many cases, great mischief was done to both systems of vessels, and the arteries once ruptured would give the greatest quantity of blood : but to ascertain this with more certainty, I made the following experiment. I wounded the femoral artery of a puppy obliquely; the opening in the skin was made at some distance from the artery, by a couching needle; the blood that came from the small orifice in the skin

* [Bichat's opinion respecting the deleterious effects of venous blood, has been already briefly adverted to. Dr. Kay, however, found that when venous blood was injected in small quantities into the arteries it did not destroy life, or manifest any directly poisonous effects. Hybernating animals continue to circulate black blood during the period of their torpidity, with the effect of rather increasing their muscular irritability. -(Hall in Phil. Trans. 1832.) Mr. Owen found that in the kangaroo the ovum did not connect itself with the mother, or the chorion put forth any villi until the period of gestation had two-thirds elapsed, although the foetus continued to grow during this time without respiration, or any office vicarious of it. (Phil. Trans. 1834.) In cholera, the blood in the arteries is perfectly black, and yet the functions of the brain remain perfect to the last, although undoubtedly the animal and vital functions are much enfeebled. Besides whieh, many other facts are mentioned in the present treatise which clearly require some modification of Bichat's doctrine, in order to explain all the phenomena which relate to this subject.] GENERAL PRINCIPLES OF THE BLOOD. Q] was florid. The cellular membrane swelled up very much; about five minutes afterwards I punctured the tumour, and the blood was fluid. In ten minutes I punctured it again ; the blood was thinner, and more serous, but still florid. In fifteen minutes I punctured it again : at first only serum issued; upon squeezing, a little blood came, but still florid; the mass now seemed to be principally coagulated, which prevented further trials. Some days after, when I cut into the swelled part, I found the blood as dark as common venal blood; so that here the change had taken place after coagulation. When I had plaster of Paris applied to my face to make a mould, in the taking it off it produced a kind of suction on the fore part of the nose, which I felt; and when the plaster was removed, on observing the part it was red, as if the cells of the skin were loaded with extravasated blood; this was then of a florid red, but it soon became of a dark purple, which showed that it was arterial blood, and that by stagnating in the cells of the body it became of the colour of venal blood. Blood may even be rendered dark in the larger arteries by a short stagnation. I laid bare the carotid artery of a dog for about two inches in length; I then tied a thread round it at each end, leaving a space of two inches in length between each ligature, filled with blood; the external wound was stitched loosely up : several hours afterwards I opened the stitches, and observed in this vessel that the blood was coagulated, and of a dark colour, the same as in the vein. Thus, I have also seen, when a tourniquet has been applied round the thigh, and the artery divided, that when it was slackened, the first blood came out of a dark colour, but what followed was florid. This I have seen in amputations, when a tourniquet had been applied for a considerable time; and it is commonly observed in performing the operation for aneurism. July, 1779, Mr. Bromfield had a patient in St. George's Hospital with an aneurism of the crural artery, about the middle of the thigh : the artery had been dilated about three inches in length. The operation was performed, in which the artery was tied up above the dilatation, three or more inches, for security. When this was done, the tourniquet was slackened, and a pretty considerable bleeding was observed, seemingly at the lower orifice, leading from the dilated part, which, at first, was supposed, from its colour, to be the venous blood that had stagnated in the veins by means of the tourniquet; but this it could not be; and it was found to flow from the lower orifice of the artery, which was immediately tied ; we must suppose that the motion of the blood, in making this retrograde course, was very slow, for it had first to pass off into small collateral branches above where it was tied, then to anastomose with similar small ones from the trunk below, and then to enter that trunk, all of which must very much retard its motion ; and, indeed, the manner of its oozing out of the vessels showed such a retardation. This motion of the blood, though in the arterial sys- 92 HUNTER ON THE BLOOD. tern, was in some respects similar to the motion of the blood m both systems of vessels. . . This last circumstance plainly indicates a communication of the arteries above the aneurism with those below, by means of the anastomosing branches. The blood from the lower orifice flowed without any pulsation, which must have been owing to its coming into the large artery below by a vast number of smaller ones at different distances, and of course at different times ; but probably the chief cause of this want of pulsation in the great artery was, that the power of the heart was lost in the two systems of smaller arteries above and below; for the second system, or those from below, became in a considerable degree similar to veins, and the great artery in the leg below the aneurism was like a considerable vein. A young man, servant to Henry Drummond, Esq., having had a knife run into his thigh, which wounded the crural artery, a considerable tumour came on the part, consisting chiefly of blood extravasated, and lodged in the cellular membrane. This in some degree stopped the flowing of the blood from the cut artery, and on dilating the wound, so as to get to the artery, I observed that the extravasated blood in the cellular membrane was of the venal colour. On exposing the artery, which was first secured from bleeding by a tourniquet above, and then slightly slackening that instrument, the first blood which flowed from above was dark, and even was taken for venous blood by the operator; but he was soon convinced that it was arterial by the florid colour of that which almost immediately ensued. I observed that the colour of the blood was as dark as that of any venous blood I ever saw. From these experiments and observations, we must conclude that the colour of the blood is altered, either by rest or slow motion, in living parts, and even in the arteries; this circumstance takes place in the vessels as the motion of the blood decreases.*

* [Arterial blood is also blackened in vacuo, and when placed in media which exert no apparent chemical action upon it, such as hydrogen and nitrogen (Priestley on Air, iii. 363-4); nay, arterial blood gradually blackens when confined in pure oxygen, and cannot be again brightened by this agent (Thompson, Syst. of Chem., iv. 474), although, by the addition of any neutral salt having an alkaline or earthy base, the colour is instantly restored. These facts are clearly against the notion, to be adverted to presently, of free carbon being the cause of the black colour of the blood, because as much of this substance must exist in the blood at the commencement of the experiment as at the termination. Neither is it easy to reconcile these phenomena with Dr. Stevens's theory of arterialization; for if carbonic acid is the cause of the dark colour, how is it that arterial blood (which, according to this author, contains no carbonic acid), is rendered black, and venous blood still blacker, by being placed in vacuo; since the 6alts remain the same, while the effect of a vacuum would evidently be rather to extract a part of the carbonic acid than to increase its amount] It is possible that these phenomena may depend on some alteration in the constitution of the clot, arising from a mutual play of affinities between its proximate elements, thus the blood is also observed to become venalized in the living body from the mere fact of stagnation. Sir Astley Cooper found that those changes which constitute the venalization of the blood m the body were not effected under extreme cold, so that the blood remained GENERAL PRINCIPLES OF THE BLOOD. 93- Another observation occurs, viz., that the whole of the limb below the ligature, where the crural artery had been taken up, must have been entirely supplied with such altered blood; and as it kept its life, its warmth, and the action of its muscles, it is evident that the colour of the blood is of little service to any of those properties. It is probably from this cause that granulations on the lower part of the lower extremity look dark when the person stands erect, as well as in very indolent sores, however situated. Another observation strongly in favour of the supposition that rest is a cause of the change of blood from the scarlet colour to the dark or modena, is taken from the common operation of bleeding; for we generally find the blood of a dark colour at its first coming out, but it becomes lighter and lighter towards the last. Some reasons may be given for this: first, it has stagnated in the veins while the vein was filling, and the orifice making, which occupy some time, and may render it darker than it otherwise might have been in the same vein; secondly, when there is a free orifice the blood may pass more readily into the veins from the arteries, and therefore may be somewhat in the state of arterial blood, which may occasion the last blood to be rather lighter. What amounts almost to a proof of this is, that although a ligature is tied so as to stop the passage of the blood to the heart, and therefore it might be supposed not to have so free a passage from the arteries as in common, yet, from the following observations, it appears that it certainly has a much freer; for if the orifice be large in a full-sized vein, the arm beyond the orifice will be much paler than the natural colour, and the blood will become more florid; but if, on the contrary, the vein be small, and little blood passes, it will retain its dark colour; this, however, would appear not always to be the case. I bled a lady, whose blood at first was of a dark colour; but she fainted, and while she continued in the fit the colour of the blood that came from the vein was a fine scarlet. The circulation was then very languid. We may observe that venal blood in the most healthy is commonly, if not always, the darkest; and that whenever the.body is the least out of order, it is then not so much changed from the florid to the very dark purple. This I have often observed, and particularly recollect a striking instance of it in a gentleman who had a

florid throughout the whole system of those animals which perished from cold (Dr. Hodgkin,s Notes to Edwards') ; whereas, under the influence of moderate warmth, such as that of the body, these changes take place, slowly on extravasated or stagnating blood, but instantly in the extreme capillaries. It will be sufficient to have noticed in this place the analogy which subsists between the venalization of the blood under these different circumstances, without pretending to decide whether these phenomena depend on the gradual union of carbon and oxygen with each other,or on any other cause. The subject will be resumed in a future note.] « Se3 Edwards on Physical Agents, &c, published in the Select Medical Library for 1838. 9 91 HUNTER ON THE BLOOD. slight fever; his venal blood was quite florid, like arterial blood. This could not have arisen from the increase of the blood's motion, or from being kept up in the veins by the fever, for it was slight.* The blood will change its colour from the scarlet to the modena in different situations, ^according to the mode of circulation. In animals which have lungs and a complete double circulation, the darkest blood will be where it comes (if I may be allowed the expression) to get anew its bright colour; for instance, in the arteries of the lungs, and of course the brightest in the veins of the same part, which will be continued more or less into the arteries of the other circulation, where again it will begin to change, except in one stage of life of some animals which do not use their lungs, such as foetuses; but in such foetuses as convert animal matter into nourishment, (and therefore, most probably, must have it influenced by the air, although not by means of the lungs of the chick, such as the chick in the egg,) we find the blood in the veins of their temporary lungs of a florid colour, while it is dark in the arteries ; so that it has become of a dark colour, in its passage to and from the heart; but in the more perfect animals the blood, I believe, becomes darker and darker a& it proceeds from the heart, till it returns to the heart again; but this change is very little in the arterial system, more especially in vessels near the heart, as the coronary arteries. The change of colour is more rapid in the veins, but it is not equally made through the whole venous system ; for it will be produced more quickly in the lower parts of the lower extremities than in the veins near the heart; it begins, most probably, where the motion first has a tendency to become languid , and this usually takes place in the very small arteries; for in bleeding in the foot, or on the back of the hand, I have observed, in general, that the blood is of a more florid red than in the bend of the arm.t

* I believe the blood does not become dark by standing in an inflamed part. I have seen cases of apoplexy where the person died some days after the attack. I have found the pia mater inflamed in several places, even to the length of inflammatory transfusion, forming dots, all of which were of a florid red colour, while the other parts of the same membrane, the blood in the larger vessels, and also the extravasated blood, were of the usual dark colour. f [In order to complete the general view of the changes which the blood undergoes during the course of its circulation, I propose very briefly to advert to the subject of respiration, relying upon my reader's indulgence-for the imperfection of a sketch which is not capable of being we'll comprised within the limits of a note. Mr. Hunter, although nochemist, had sufficient sagacity to perceive the insufficiency of all existing theories of respiration, and therefore confined himself to the bare statement of facts, leaving it to future observation to discover the clue by which these might be explained. He admits that the arterialization of the blood, so far at least as change of colour is concerned, is wholly irrespective of vital causes ; but he seems to have regarded * the renewal of the vitality of the blood as dependent on some inexplicable effect of the vital air, from which the idea of any chemical changes is wholly excluded. Undoubtedly we shall not err in regarding change of colour as merely expressive of some other more important changes effected by respiration; hut then these changes are essentially chemical, and it is on these alone that the vitalizing properties of the blood de- GENERAL PRINCIPLES OF THE BLOOD. 95 § 5. Of ihe Quantity of Blood, and course of its Circulation.

It appears to me impossible to ascertain the quantity of blood in the body, and the knowledge of it would probably give very little assistance towards better understanding the ceconomy of the animal.

pend. I shall also premise that the principal seat of these changes is in the pulmonary and systemic capillaries; for although, under certain circumstances, a similar change may undoubtedly occur, as well in the great vessels as in extravasated blood, yet the change is generally instantaneous in the natural course of the circulation: that is, the blood enters the capillaries of the lungs-black, and is immediately converted to red ; and on the other hand, it is scarlet in the smallest arterioles of the body, but black in the minutest radicles of the veins. These systems antagonize each other, so that whatever the blood acquires in one it loses in the other, and vice versa. If venous blood be exposed to atmospheric air, its colour is soon converted from black into scarlet; a portion of oxygen is absorbed, and an equal proportion of carbonic acid is disengaged. If, instead of atmospheric air, pure oxygen is employed, these effects are more quickly and more characteristically developed ; but they are not produced by any gases (with the exception perhaps of carburetted hydrogen), which have no oxygen as an element. Such are the simple phenomena of arterialization, which equally take place in and out of the body, although not with equal rapidity. Thus, Allen and Pepys found that a man of average size breathed about nineteen times in a minute, and took in about 16£ cubic inches of air at each inspiration. About 26-6 cubic inches, at 50°, of oxygen were calculated to be withdrawn from the atmosphere per minute, and the same quantity of carbonic acid to be emitted from the lungs, making of the latter about 38,232 cubic inches per day, or nearly 10| oz. troy of solid carbon. (Phil. Trans. 1808, p. 256.) Atmospheric air consists of 79 parts of nitrogen and 21 of oxygen; but, according to Allen and Pepys, the nitrogen remained unaffected by the process of respiration, which consisted solely in the abstraction of a quantity of oxygen exactly sufficient to convert the carbon of the blood into carbonic acid, bulk for bulk, equal with that of the oxygen abstracted. It was therefore natural to suppose that the black colour of venous blood depended on the presence of free carbon, or carbon in some peculiar state of combination, which was given out from the lungs in the act of respiration. The blood, in short, was supposed to be carbonized in the extreme capillaries of the body, and to be decarbonized in the lungs. It has been ascertained, however, by more correct experiment, 1st, that the quantity of oxygen lost does not always correspond with the quantity of carbonic acid emitted from the lungs; 2d, that nitrogen is absorbed or given out under certain circumstances; and 3d, that carbonic acid exists ready formed in venous blood (see note, p. 35). Dr.-Edwards found that the quantity of oxygen consumed above the quantity of carbon produced, varied in the lower tribes of animals from nothing to one-third of the whole (De Plnfluence des Agens physiques sur la Vie*); while, on the other hand, it has been remarked by Dr. Prout that the amount of carbonic acid produced also varied according to the age of the animal, the diet, the time of the day, the season of the year, the state of the atmosphere, the quantity of exercise, and many other physical circumstances. (Ann. of Phil.,'\\. 330., and iv. 331-4.) Edwards found similar variations in the quantity of nitrogen (op. cit., p. 420). When pigeons were confined in oxygen gas containing from one to two per cent, of nitrogen, the volume of gas remained undiminished, and only so much oxygen were found t". have beeR abstracted as would have happened if the pigeons had been made to respire common air; but then a a See Edwards on Physical Agents, &c, in the Library for 1833. 96 HUNTER ON THE BLOOD. The quantity of blood is probably as permanent a circumstance as any, and not depending on immediate action : we have not one hour

much smaller quantity of carbonic acid was formed, the deficiency being made up by an evolution of nitrogen. . , „ By varying the experiment, and mixing oxygen and hydrogen with a small proportion of nitrogen (the oxygen being in the same proportion as in common air), no loss of oxygen was sustained, but a quantity of hydrogen disappeared, which was exactly replaced by an eqnal proportion of nitrogen. (Alien and Pepys, Phil. Trans. 1829, p. 279.) During the month of March Dr. Edwards confined frogs in pure hydrogen, from which he found tRat volumes of carbonic acid, nearly equalling the whole bulk of the animals employed, were evolved, although the lungs had previously been exhausted by pressure. A young kitten also, confined for nineteen minutes in the same manner in hydrogen, evolved twelve times more carbonic acid than could be accounted for by the residual air in the lungs when the experiment began. (Op. cit., pp. 437-465.) It may be distinctly concluded, therefore, from these facts, that the lungs are capable of absorbing and giving out gaseous matters, particularly oxygen and carbonic acid. In man the quantity of oxygen abstracted from the atmosphere pretty exactly equals the quantity of carbonic acid produced ; but whether the whole oxygen is absorbed, and the whole carbonic acid evolved from the blood, or whether the lungs are merely the seat in which the carbon of the blood combines with the oxygen of the air to form carbonic acid, remains at present a question. From the system of antagonism which is evinced in many of the functions of the animal ceconomy, Dr. Edwards is disposed to regard the former of these opinions as most probable (op. cit., p. 43?); and certainly, when we reflect on the importance of the respiratory functions, it is reasonable to suppose that this is actually the case. What the exact changes are which are wrought on venou9 blood, so as to restore to it its vivifying properties, are known, but it seems to fall infinitely short of our notion of the importance of this function to suppose that it merely rids the blood of a little carbon. This would be merely to ascribe to respiration a negative effect, whereas it is scarcely possible to refrain from the conclusion that this important function confers on the blood new and positive qualities, by more completely animalizing its various elements. Such, then, are the phenomena of respiration; but what are the immediate causes of the change of colour in the blood 1 The scarlet colour is instantly restored to venous blood by the contact of oxygen, and hence it was universally supposed that the arterialization of the blood depended on the absorption of this gas. But this has been denied by Dr. Stevens (On the Blood, p. 8, et passim), whose views are: 1st, That the colouring matter of the blood is naturally black, but that " scarlet is the natural colour of the vital current; and this it owes to another cause." 2d, "That carbonic acid is the cause of the dark colour in the venous circulation," having "ascertained by numerous experiments that all the acids blacken the blood." 3d, " That oxygen brightens its colour, not by addition, but by attracting or removing the carbonic acid." And 4th, "That the scarlet colour is produced by the action of the saline ingredients on the colouring matter." He affirms that "the scarlet colour exists in the blood independent of oxygen, or, at all events, oxygen of itself cannot produce either the red or the arterial appearance, for when we cover the crassamentum, when it first coagulates, with a layer of distilled water, or any other fluid which does not contain saline matter, the acid may be removed by the oxygen, or absorbed by the water, but the colour becomes darker than it had been before. On the other hand, when we immerse the black and saltless crassamentum in any clear saline fluid, the colour instantly changes from dark venous to bright arterial; and when the fluid which we use is sufficiently impregnated with saline matter, this change is produced tvhen we make the experiment, as I have frequently done, even in an atmosphere of carbonic acid. Oxygen, however, is essential to life, for without this the heavy deleterious gas, which is the cause of the impurity of the venous circulation, would not be removed in the pulmonary organs ; the blood in the extreme circulation is converted from arterial to GENERAL PRINCIPLES OF THE BLOOD. 97 less and another hour more; nothing but accident or disease can lessen the quantity; the first probably immediately, the other slowly; but even then, although under par, it is so slowly made up as not to

venous, partly by the loss, or rather by the change of form in the oxygen which it contains, and partly by the addition of carbonic acid ; but when this dark or acidified blood is exposed to the air in the lungs, the oxygen instantly removes the acid from the circulation." Suoh is a brief outline of Dr. Stevens's views, according to which oxygen plays the following part in respiration, namely, at first it lifts out or carries off the carbonic acid of the blood by virtue of a " latent power of attraction;" and secondly, having performed this office, it is absorbed into the circulating fluids, where it gradually attracts carbon, from the proximate principles of the blood working important changes on the substances, and giving rise to the production of carbonic acid. This union of carbon and oxygen may slowly take place, as we have seen in the preceding note, even out of the body, and still more rapidly in the great vessels of the living animal; but undoubtedly the principal seat of these changes is in the extreme capillaries of the periphery, where the change from arterial to venous is instantaneous, and where, it must be evident,-the affinity of oxygen for carbon must be exercised under the most favourable circumstances, in consequence of the minute state of division in which the combining elements are presented to each other, not to mention the controlling influences of the nervous power over this system of vessels, as evinced in the functions of secretion and nutrition, which are merely parallel examples of the exercise of complicated chemical affinities. Whatever may be thought of several parts of these views, it seems to be an incontestible fact that oxygen alone is incapable of restoring the arterial tint to blood which has been rendered black by immersion in water. Dr. Turner, with the assistance of his friend and colleague Mr. Qiiain, records the following experiment, which 1 shall recite in his own words. " I collected," he says, " some perfectly florid blood from the femoral artery of a dog; and, on the following morning, when a fiim coagulum had formed, several thin slices were cut from the clot with a sharp penknife, and the serum was removed from them by distilled water, which had just before been briskly boiled and allowed to cool in a well-corked bottle. The water was gently poured on these slices, so that while the serum was dissolved, as little as possible of the colouring matter should be lost. After the water had been poured off and renewed four or five times, occupying in all about an hour, the moist slices were placed in a saucer at the side of the original, clot, and both portions shown to several medical friends. They all, without hesitation, pronounced the unwashed clot to have the perfect appearance of arterial blood, and the washed slices to be as perfectly venous; the colour of the latter in fact was quite dark. On restoring one of the slices to the serum of the same blood, it shortly recovered its florid colour; and another slice, placed in a solution of bicarbonate of soda, instantly acquired a similar tint. In thus brightening a dark clot by a solution of salt or a bicarbonate, the colour is often still more florid than that of arterial blood ; but the colours are exactly alike when the salt is duly diluted. " I am at a loss to draw any other inference from the foregoing experiment than the following;—that the florid colour of arterial blood is not due to oxygen, but, as Dr. Stevens affirms, to the saline matter of the serum. The arterial blood which had been used had been duly oxygenised, as it is called, within the body of the animal, and should not in that state have lost its tint by mere removal of its serum. The change from venous to arterial blood appears, contrary to the received doctrine, to consist of two parts essentially distinct: one is a chemical change essential to life, accompanied with the absorption of oxygen and evolution of carbonic acid ; the other depends on the saline matter of the blood, which gives a florid tint to the colouring matter after it has been modified by the action of oxygen." (Elem. of Chemistry, 4th edit. 1833, p. 903.) As it would lengthen too much the discussion of the present subject to examine fully all the objections which may be urged to this theory, I shall content 9* 98 HUNTER ON THE ELOOD. constitute sudden variations; vet, when we come to consider the varieties in the pulse, we sho'uld imagine there would be great

myself with making two or three observations which strike me as being most important. . , , . , 1. Oxygen is said to have no positive concern in producing the red colour of the blood ; but a stream of oxygen passed through a solution of colouring matter, previously rendered florid by a neutral salt, unquestionably exalted the vividness of the tint. Consequently oxygen is not entirely a passive agent. 2. Oxyo-en is said to possess a " latent power of attraction tor carbonic acid, by which it lifts this gas out, and, as it were, carries it off from the blood; but the ascription of such a property to oxygen is unphilosophical, as the phenomenon in question may be referred with more propriety to the general law of endosmose and exosmose, according to which, gases, by virtue of their elasticity, mutually penetrate and displace one another, such penetration and displacement being always reciprocal. (See Amer. Jour, of Mtd. Sci., vii., pp. 23, 36.) Besides, as the rate of penetration for carbonic acid and oxygen is respectively as 5£ and 113 minutes, while that for nitrogen is too inconsiderable to be assigned, it would not be possible, even admitting an attraction between gases to exist, to explain this property of oxygen; for whatever may be the rate of penetration, the attraction between gases must be equal; consequently, as the proportion of nitrogen to oxygen is as 79 to '21, the attractive power of the former will be nearly four times greater than that of the latter, and be moreover constantly present (in consequence of the low rate of penetrativeness of this gas) to aid in *' lifting out the carbonic acid." From these considerations, therefore, I conclude that the ascription of a latent power of attraction to oxygen is both ao unfounded and an inadequate supposition. 3. The presence of oxygen and the absence of carbonic acid in arterial blood have never been satisfactorily ascertained by accurate experiment; for, notwithstanding the assertion of Dr. Stevens that arterial blood contains no carbonic acid, a different result has been obtained by MM. Tiedemann and Gmelin (Poggendorfs Annul., xxxii.), so that this point must certainly be regarded at present as undecided. 4. It has also been objected, 1st, that venous blood coagulated in .vacuo parts with a portion of its carbonic acid, and yet remains black, nay blacker than before, although if oxygen be admitted in this state the red colour is restored; and 2d, that arterial blood (as has been remarked in the preceding note") grows black when coagulated in vacuo, or even when confined in pure oxygen. In answer to the first of these objections, it has been replied that the attraction between carbonic acid and blood is greater than can be overcome by one atmosphere, so that the air-pump is an insufficient means of ridding the blood of this gas, but only draws it to the surface, by which it blackens it still more. But this explanation is not satisfactory ; because although the air-pump cannot draw out the whole, it yet draws out a part; besides which, hydrogen and nitrogen, which draw out the whole, strongly I lacken the blood, although they have no chemical action upon it. (Dublin"Journ., ii. 72; Lancet, 1S31-32, ii. 659; Mtd. Gazette, xi. 881.) In respect to the gradual blackening of arterial blood in pure oxygen, it has been replied that the blood acts on itself when out of the body in a way somewhat analogous to what happens to it in the capillaries of the living animal (see preceding note), that is, various complex affinities are brought into exercise from tie union and gradual action of the oxygen on some of the component parts of the blood, in consequence of which the whole composition of this fluid is altered, and probably carbonic acid produced. But this explanation is not more satisfactory than the preceding, because, in the first place, a number of things are here assumed which are not proveable, and in the second place it is reasonable to suppose that the blackening effect on the blood is always due to the same cause ; which cause cannot be the one here assumed ; because, if it were, the oxygen which is present would invariably carry off the carbonic acid as last as it is generated, and restore the red colour. (See Williams in M'-d. GENERAL PRINCIPLES OF THE BLOOD. 99 varieties in the quantity of blood. The quantity I think must be considerable when we reflect on the use of this fluid; the quantity of supply or food necessary to keep it up; that it supports the body and life everywhere; and that it forms the pabulum of many secretions. All these cannot depend on a very small quantity of this fluid without conceiving at the same time an extremely quick change. There seem to be two modes of judging, both of which are evidently liable to objections in point of accuracy, and they differ so much as to show that neither can be right. One is, to calculate how much may be in an animal from the quantity it will lose in a short time. I have seen several quarts thrown up from the stomach in a few hours, even by a very thin, puny person ; and, on the other hand, if we had not this proof we should suppose there

Gazette, xvi. 813.) With respect to the readmission of oxygen restoring the red colour to arterial blood which has been blackened in vacuo, I believe no explanation has yet been attempted, although the fact itself has been partly denied. Upon the whole, therefore, these are real objections, which must be allowed their due weight in considering this subject. 5. The objection that carbonic acid does not blacken the blood (Lancet, ut supra) has been completely removed by Mr. Hoffman, who found that a stream of carbonic acid passed through oxygenized blood gradually converted it to a black colour. (Med. Gazelle, xi. 881.) The same author has also confirmed the statement of Dr. Stevens that a stream of carbonic acid gas passed through blood which has been previously reddened by a neutral salt renders it irrecoverably black. 6. A dark clot is equally arterialized when covered with milk or white of egg (Priestlei, on Air, iii.; Wells in Phil. Trans., 1797,) as when covered with its own serum. The effect indeed is more slowly produced, but it is accompanied with the same loss of oxygen and the same evolution of carbonic acid, consequently the salts of the serum cannot be the cause of the red colour. But this objection is of little weight, 1st, because a minute portion of salts is contained in milk and white of egg; and 2d, because the further contraction of the clot may extrude a still further portion of serum, which coming in contact with the surface of the clot may arterialize it. 7. Upon the supposition that free carbonic acid is the sole cause of the dark colour of the blood, by suspending the reddening tendency of the salts, the addition of a minute quantity of any pure alkali, sufficient to neutralize the acid, ought immediately not only to restore this property to the salts, but to increase it, by adding to the previously existing salts a carbonated alkali; but the addition of any quantity of a pure alkali is found rather to increase the blackness of the blood. (Williams in Med. Gaz., ut supra.) Considerable weight is undoubtedly due to several of these objections, although they do not appear to me to be of that nature that they may not possibly be removed by further inquiries. The following inferences seem at least fairly deducible from the preceding considerations: 1st, that air or oxygen without salt has no power of reddening the blood; 2d, that salt without air has this effect; 3d, that carbonic acid is probably the cause of the black colour of venous blood, by overpowering the natural reddening tendency of the serum; and 4th, that the removal of the carbonic acid is the cause of'the red colour, by allowing the serum to exercise this tendency unobstructed. Independently of any theory these are novel and interesting facts, for which we are mainly indebted to Dr. Stevens. It cannot, however, be concealed that the theory of respiration, calorification and arterialization which he has built upon them is defective in many main points, although I consider it on the whole as open to fewer objections than any other, and as fully deserving of being followed up with further and more accurate experiments.] 100 HUNTER ON THE BLOOD. could be but very little, when a few ounces will make a person faint. I have an idea, however, that people can bear to lose more by the stomach than in anv other way. Besides, it becomes a matter almost of surprise how little is commonly found in the dead body; but I believe in disease it in some degree diminishes with the body; for more is to be found in those who die suddenly, or of acute diseases; and even in some who die of lingering diseases, as of dropsv, we have a considerable quantity of blood. The only way of accounting for this is, that in a common lingering illness there is less-blood, and in a dropsy it coagulates less; for the strong coagulation squeezes out the serum, which, I imagine, transudes after death, and is not observable. It would appear upon the whole, that the quantity of blood in an animal is proportioned to the uses of that blood in the machine, which, probably, may be reckoned three in number: the first is simply the support of the whole, which includes the growth or increase of parts, the keeping the parts already formed to their necessary standard, and also the supply of waste in the parts. The second is the support of action, such as the action of the brain and muscles, in which is produced uncommon waste; and thirdly, secretion ; all of which will fluctuate except the simple support, but more particularly the support of action. I have already observed that the anastomosing of vessels gives greater space for blood. Probably a paralytic limb would give the necessary quantity for simple support.* There is nothing particular in the veins, so as to give an idea that they were intended to increase the quantity of blood: they hold, however, more than the arteries, which certainly adds to the quantity ; but the increase of size lessens the velocity. They form plexuses, and what are called certain bodies : as the plexus reteformis in the female, and corpora cavernosa and spongiosa in the male. We see how little blood supports a part in an aneurism; and, probably, slowness of motion is suitable to little blood. It must have appeared in the account of the different colours of the different parts of the body, arising from the proportion of red blood, that some parts must have much more blood than others; and we have now to mention that some parts have much larger

* [On bleeding a young ass to death, of the weight of791bs., Pereival obtained 5£lbs. of blood, that is, it perished from a loss of about Jjth of its weight: Sir Astley Cooper estimated the proportion which an animal might lose before death at about ^th. Probably Haller's estimate of the actual quantity of blood in the body approaches as nearly to the truth as any, viz., ^th its weight; of which 2thsor more were supposed to be in the veins, and ith or less in the arteries. (El. Phys., v. i. 3.) As the proportional quantity of blood varies very considerably in different animals, it is probable that age, temperament, food, exercise, and other external circumstances have also a considerable influence in this respect in man. Thackrah found that the quantity of evaporable fluid in a Sf *W?S ?21'6, the solid beinS 378'4 (°P- «"'•. P- 232) : but this gives no idea of TJT Ur q"anmI°[ blood in lheb»°y' for all the animal textures contain abundance of water, which would necessarily come into the account.] GENERAL PRINCIPLES OF THE BLOOD. 101 vessels going to them than others. This idea is confirmed, by the blood being the moving material of life, and taking a part in every action of it: its quantity is to be found in proportion to those actions; and since the body is a compound of parts, or rather of actions, whose uses are known to vary considerably, we find blood directed to those parts in proportion to their actions; and this we judge of by the size of the vessels and redness of the part in those animals which have red blood, and we may suppose the same in those which have not this part of the blood. The brain has considerable vessels, &c, going to it, yet its substance is white, which is in some degree owing to its opacity ; the tongue is vascular; the thyroid gland is vascular; the lungs allow of the passage of the whole blood in most animals, and therefore have always a current of blood through tthem equal to the whole; the liver is extremely vascular, which is known from its proportion of vessels, as well as its colour; and as there is in this viscus a peculiar circulation, the very great quantity of blood passing through it adds to the quantity in the whole body. The spleen is extremely vascular, as are likewise the kidneys; the stomach and intestines have considerable vessels going to them, and the muscles in general, more especially those of labouring people; for labour increases the quantity of blood in the whole, beyond simple nourishment in the full-grown, or beyond the mere growth in the young. In tracing the course of this nourishment in animals (which consists ultimately of the blood), from the most simple to the most complicated there is a pretty regular series; although this regularity is interrupted whenever there is a variety in the circumstances, which are to be taken into the account; but the whole of this forms too extensive a subject for our present consideration. If I were to begin at the formation of the blood, I should first treat of digestion in those animals which have stomachs; but this is a distinct subject. We may, however, begin with its immediate consequences, as digestion produces the first and most essential change, viz., the conversion of the food into a fluid called chyle. The chyle is the immediate effect or product of digestion, and is the seed which, as it were, grows into blood, or may be said to be the blood not yet made perfect. The chyle, to appearance, varies in different animals. In the quadruped and in the crocodile it is white; but in most o2|fir5i|.ni^jJ^)Tt-< is, transparent -...where it is white its parts are more conspicuous than where'"it isfransparent. In this respect it is similar to the red blood, and is found to consist of a coagulating matter, a serum, and white globules, which render it of a white colour, so as in some degree to resemble milk. These globules are smaller than the red globules of the blood, and about the size of those in the pancreatic juice; they retain their figure in water, and therefore are not similar to the red globules; they retain their round form in the serum; they are also specifically heavier than their own lymph and serum. One would naturally suppose from observing the chyle to have 102 HUNTER ON THE BLOOD. globular particles in certain animals that they formed the red globules in the blood; but when we consider that the chyle in fowls has no globules, and yet that they have red blood, we must conclude that they do not answer this purpose.* The first motion of the nourishment in most animals consists in the absorption of the chyle from the appendages of the stomach; and in many this alone appears to constitute the whole, as they have no such organ or viscus as a heart, to which it may be carried ; and in such it may be supposed to be, in its mode of distribution, somewhat similar to the mesenteric veins and vena porta?: the parts therefore assimilate, and dispose of it themselves; but this structure belongs only to the most simple, or the first class of animals. In those which are more perfect, where parts are formed for each particular purpose, the chyle is brought to one organ, called the heart, having first joined the venous blood, which now requires a similar process, and both are sent to the lungs, where most probably the chyle receives its finishing process; and from thence it comes back to the heart again, to be sent to every part of the body.f In those animals that have hearts we are to take into the account a number of particulars. First, the blood's motion in consequence of that organ; secondly, the principal intention of that motion, viz., that it may be prepared in the lungs, which introduces breathing; thirdly, the variety in the kinds of lungs; fourthly, the different kinds of media in which animals are obliged to breathe for the purpose of extracting matter employed in the preparation of this fluid. In this investigation we shall find there is not an exact or regular correspondence in all the parts so employed. This irregularity arises from animals breathing different substances: such as some breathing the common atmosphere, in which is included the respirable air; others water, in which air is included, as fish. Some breathe both air and water; while there are others which breathe air in their perfect state, but water in their first periods or imperfect state of life.J If we were to take a view of all these systems, each should be considered apart, with all its peculiarities or connexions, together with the different systems, as they gradually creep into one another, some being perfectly distinct, while others partake more or less of both. The complete system is always to be considered as the most perfect, although it may belong in other respects to a more imperfect order of animals. It has been supposed by physiologists that as the blood is found to consist of different parts, or rather properties, that certain parts or properties were determined to certain parts of the body, for particular purposes; but from the frequent anastomosis of arteries,

* [See note, p. 71.] t The circulation in fish is an exception to this. 4: In this account I do not include animals in embryo, and some others, which do not breathe at all. GENERAL PRINCIPLES OF THE BLOOD. 103 the great variety in their number and origin, and the different courses which they take in different bodies, it is very evident that there can be no particular blood sent to any part of the body where the whole blood can circulate. Many unnatural situations of parts show this. For instance, the kidneys sometimes have one artery only on one side, and two, three, or four on the other: on one side they may arise from the aorta as high nearly as the superior mesenteric, and on the other as low almost as the division into the two iliacs: and in some cases a kidney has been formed in the pelvis, and the artery has arisen from the iliac. The spermatic arteries too, sometimes, arise on one side from the aorta, and on the other from the emulgents or the arteria capsular renalis. If there was a particular blood sent to every gland, we should expect to find urine secreted in the testicle, when its artery arose from the emulgent; but as the blood visibly consists of different parts in those animals we are most acquainted with, and whose physiology is probably best known to us, and as one part of the blood can be traced in the vessels, we can determine with sufficient accuracy the proportions of blood sent, as well as the different kinds. Thus, the red part of the blood informs us how far it is carried; and we find that our coloured injections nearly correspond with this information. I may here first remind the reader that the red globules are the grosser part of the blood, and therefore wherever these exist we have the blood with all its parts indue proportion and unsCparated; but the construction in many parts of an animal is such that the red blood is excluded, and this also excludes every coloured powder we can inject; the vascularity, therefore, of such parts is not known, as has been mentioned already. Through them the coagulating lymph only can pass, and probably the serum, for the simple nourishment of the parts. Of this nature are tendons or tendinous parts, ligaments, elastic ligaments, cartilages, especially those of joints, the corneas of the eye, &c. Even the brain and nerves have not the red blood pushed so far into their substance as many other parts have : we see therefore that the whole blood is not conveyed to all parts alike, and this we must suppose to answer some good purpose; yet, upon a more particular view of this subject, we may find it difficult to assign causes for this selection of the blood ; for in many animals we find parts similar in construction and use, such as muscles, which are furnished, some with the whole blood, others"with the coagulating lymph only, with all the gradations; some animals having both red and white muscles, others having them wholly red, and others wholly white, as will be more fully explained. Even venous blood can be rendered useful when it is not to answer the purpose of nourishment; for we find the blood of the intestines and spleen going to the liver, we may presume, for the secretion of the bile, as has been already observed (p. 89). The idea of particular kinds of blood being sent to parts having particular uses, more especially where the part is employed solely 104 HUNTER ON THE BLOOD. in disposing of this.fluid, such as glands, is now, I believe, pretty well exploded ; and it is supposed therefore that the whole mass of blood is such as to be fitted for all the purposes of the machine. This idea gives to the parts themselves full power over the blood so composed, and makes us consider the circulation or motion of the blood simply.* As the blood is composed of different parts, it might be supposed that if any particular part had been expended in any process, the remainder, as returned by the veins, would show this by its different appearance or qualities. The only visible difference that I could conceive to take place was in the appearance or quantity of coagulating lymph. To ascertain this, however, I made the following experiments. Exp. 1. I opened the right side of the thorax in a living dog, and tied a ligature round the vena cava inferior, above the diaphragm.

* [It seems extraordinary that the question, whether the blood sent to any one part of the body differs from that sent to any other part, should ever have been agitated. (See note, p. 77). But to assign distinct and appropriate offices to the several elements of the blood in the functions of secretion, nutrition, &c, is altogether another question, which may plausibly enough be entertained. The observations of Bauer, Prevost and Dumas, and, lastly, of Milne Edwards, on the globules of the blood and several of the animal secretions, agreeing in this respect with the apparent globular constitution of the animal tissues, seemed for a time to estahlish a simple system of homogenesis of structure for the whole body, consisting, on the one hand, of an infinity of elementary molecules diffused through the nutritive fluids of plants and animals, and on the other hand, of these same molecules arranged in definite but diversified manners, so as to constitute , the various tissues of the body. Unfortunately, however, for the beauty of this hypothesis, the very fact of the globular constitution of the animal tissues has been recently denied by Hodgkin and Lister. (Phil. Mag. and Annals, Aug. 1827, and also App. to Tr. of Edwards's Influence of External Agents on Life, &c.») Tiedemann also affirms the same thing, and says that even where organic particles do exist they present various forms and sizes, and are unlike those of the blood. (Phys., tr. by Gully and Lane, p. 397.) So far, therefore, as relates to the use of the globular particles we are just as much in the dark as ever; for though Hunter has pointed out their connexion with the strength and vigour of the animal (p. 72), Prevost and Dumas the relation which they bear to animal heat (Ann. de Chim., xxiii.), and Dr. Christison the correspondence which exists between them and the consumption of oxygen in respiration (Edin. Med. and Surg. Journ., xxxv. 94)', yet the exact relation which either of these phenomena bears to the cause from which it is supposed to spring is altogether a secret. It has also, with equal confidence, been asserted that the fibrin of the blood constitutes the basis of muscular fibre, and that it is the great intermedium by which recently divided parts are united; the albumen also has been said to affoid the basis of the dermoidal, ligamentous, and membranous tissues of fhe body. These however, at present must be regarded as mere conjectures, in favour of which no definite or satisfactory kind of proof has as yet been offered. If, as very probably is the case, the act of assimilation carried on in the parenchymatous structure of parts is to be regarded as of the same nature with secretion, then there seems no greater reason for supposing the preexistence of muscle, or brain, or ligament, ready formed in the blood, than for imagining that bile or milk, or semen, previously exist in this fluid ; and yet no one has yet been hardy enough to affirm that either of these secretions is discoverable in healthy blood.] » In the Select Medical Library. GENERAL PRINCIPLES OF THE BLOOD. 105

I then applied my hand upon the opening, which allowed him to breathe, that the circulation might go on and fill the larger veins. When the inferior vena cava became turgid, I killed him. On the day following I examined the blood in the different veins, and found a coagulum in the emulgent,' mesenteric, vena cava inferior, splenic, and in the venae cava? hepaticae, of sizes proportionable to the sizes of the vessels ; nor was there any difference in any other way. Exp. 2. Some blood was taken from the mesenteric vein of a living dog, and similar quantities from the splenic vein, the emulgent vein, and the vena cava inferior, below the openings of the emulgents. These four quantities were taken in four separate cups. They all soon coagulated; and if there was any one later of coagulating than another, it was that from the mesenteric veins. On standing twenty-four hours, the coagula were all of the same firmness.

§ 6. Of the Living Principle of the Blood.

So far I have considered the blood, and in the common way; but all this will explain nothing in the animal ceconomy, unless we can refer it to some principle which may show the nature of its connexion with the living solids in which it moves, and which it both forms and supports. If we should find this principle to be similar to life in the solids, then we shall see the harmony that is supported between the two, and we shall call it the living principle of the blood. Without some such principle, all we have been examining is like dissecting a dead body without having any reference to the living, or even knowing it ever had been alive. But, from the account I have given of the blood, it must have appeared that I have still in reserve a property not hitherto explained; for in treating of the coagulation of the coagulating lymph I have not been so full in my account as I might have been. As many phenomena respecting the coagulation or non-coagulation of the blood develop this principle, I have chosen in part to reserve it for this place; nor shall I be so full upon the present occasion as I should otherwise be were I writing on this subject expressly; my intention being rather to explain many appearances in the animal oeconomy, and particularly the diseases I am to treat of, than to discuss this single principle. I reserve the illustration of my doctrine for such parts of the treatise as shall be employed on these subjects; the explanations and illustrations, therefore, will be interspersed through the work, by which means they will come more forcibly on the mind. From many circumstances attending this fluid, it would seem to be the most simple body we know of endowed with the principle of life. That the blood has life is an opinion I have started for above thirty years, and have taught it for near twenty of that time, in my lectures ; it does not, therefore, come out at present as a new doctrine, but has had time to meet with considerable opposition, and also ac- 10 106 HUNTER ON THE BLOOD. quire its advocates.* To conceive that blood is endowed with life, while circulating, is perhaps carrying the imagination as far as it well can go; but the difficulty arises merely from its being fluid, the mind not being accustomed to the idea of a living fluid.f It may

* [Although the doctrine of the life of the blood did not originate: with Hunter, we are unquestionably indebted to him for its erection on a solid basis. His comprehensive mind enabled him to see more clearly than any preceding physiologist the real bearings of the question, and to devise experiments by which the specific difficulties which lay in the way might be removed. It is not alleged that the doctrine in question is demonstrable; but only that the evidence before us warrants and requires this inference,—the falsity of which has never yet been demonstrated by any of its opponents. I am not afraid of diminishing Hunter's just fame by citing the following passages from Harvey, which fully prove that the life of the blood was maintained by that celebrated man, and maintained too by the same kind of arguments. But Hunter, in the spirit of the true English maxim, acquired his rightto the property by blending his own labours with the soil; the originality of his mind improved the least thing that he borrowed, and stamped it with the imprimatur of his own genius. "Vita igitur in sanguine consistit (uti etiam in sacris nostris legimus,)quippe in ipso vita atqueanima primumelucet, ultimoque deficit.......Sanguis denique totum corpus adeo eircumfluit et penetrat, omnibus ejus partibuscalorem et vilam jugiter impertit; ut anima primo et principaliter in ipso residens, illius gratia, iota in foto et tota in qualibet parte (ut vnlgo dicitur) inesse, mcrito censeatur. .... Clare constat sanguinem esse partem genitalem, fontem vitae, primum vivens et ultimo moriens, sedemque anima? primariam; in quo, tanquam in fonte, calor primo et precipue abundat, vigetque; et a quo reliquae omnestotius corporis partes, calore influente foventur et vitam obtinent......Ideoque concludimus, sanguinem per se vivere et nutriri; nulloque modo ab alia aliqua corporis parte, vel priore vel praestantioredependere. . . . Utrumque anlem, sensum scilicet, etmotum, sanguine inesse, plurimis indiciis fit conspii-uum. ... Id nunc solum dicam; licet concedamus, sanguinem not sentire; inde tamen non sequitur, eum non esse corporis sensitivi partem, eamque praecipuam. . . . Habet profecto in se animam, primo ac principaliter, non vegetativam modo, sed sensitivam etiam et motivam j permeat quoquoversum, et ubique presens est, eodemque ablato, anima quoque ipsa statim tollitur: adeo ut sanguis ab anima nihil discrepare videatur; vel saltern substantia, cujus actus sit animus estimare debeat. . . . Hie, ne a proposito longius aberrem, sanguinem (cum Aristotelt) accipiendum censeo, non ut simpliciter intelligitur et cruor dicitur, sed ut corporis animalis pars vivens est." (De Generatione, Exer. Ii. iii.) The following extracts from Aristotle's first and .third books, on the history of animals, are probably those which are alluded to in the last paragraph:—"Sanguis nempe, instar laris familiaris, est anima ipsa in corpore......et semper quamdiu vita servatur, sanguis unus animatur et fervet......In sanguine reperitur divinum quid, respondens elemento stellarum." With more or less explicitness, the same doctrine was advanced by Willis (De Molu Muscul., p. 71), Hoffman (Opera, i. 33), Huxham (Essay on Fever), and several ether authors.] f It is just as difficult for a man born in the West Indies to conceive water becoming a solid. I recollect a gentleman from Barbadoes walking out with me one frosty morning when there was ice on the gutters, and I, without having anything else in my mind than just common observation, said, " It has been a frost in the night." He immediately caught at the word frost, and asked me, " How I knew that ?" Without thinking particularly of the cause of his question, I said, " Because I see the ice on the gutters." He immediately said, "YVherel" and I answered, "There." Having been told that ice was a solid, he put his fingers down upon it; but with such caution as bespoke a mind that did not know what it was to meet; and upon feeling the resistance it gave, he gently pulled his hand back, and looked at the ice, and then became more bold, broke it, and examined it. GENERAL PRINCIPLES OF THE BLOOD. 107 therefore be obscure at first, and it will be the more necessary that I should be pretty full in my account of it; yet the illustration of it in my account of inflammation will perhaps do more to produce conviction than any other attempt, although strongly supported by facts. It is to me somewhat astonishing that this idea did not early strike the medical inquirers, considering the stress which they have laid on the appearances of this fluid in diseases; since it (i. e., the blood) is probably more expressive of disease than any other part of the animal oeconomy; and yet all this, according to them, must have arisen from, what shall I call it 1 a dead animal fluid, on which a disease in the solids must have had such an effect. This, I think, is giving too much to the solids, and too little to the fluids. When all the circumstances attending this fluid are fully considered, the idea that it has life within itself may not appear so difficult to comprehend ; and indeed, when once conceived, I do not see how it is possible we should think it to be otherwise, when we consider that every part is formed from the blood, that we grow out of it, and if it has not life previous to this operation, it must then acquire it in the act of forming; for we all give our assent to the existence of life in the parts when once formed. Our ideas of life have been so much connected with organic bodies, and principally those endowed with visible action, that it requires a new bend to the mind to make it conceive that these circumstances are not inseparable. It is within these fifty years only that the callus of bones has been allowed to be alive;* but I shall endeavour to show, that organization and life do not depend in the least on each other; that organization may arise out of living parts, and produce action; but that life never can arise out of, or depend on, organization. An organ is a peculiar conformation of matter (let that matter be what it may), to answer some purpose, the operation of which is mechanical; but mere organization can do nothing even in mechanics; it must still have something corresponding to a living principle, namely, some power. I had long suspected that the principle of life was not wholly confined to animals, or animal substances endowed with visible organization and spontaneous motion; I conceived that the same principle existed in animal substances devoid of apparent organization and motion, where there existed simply the power of preservation. I was led to this notion about the year 1755 or 1756, when I was making drawings of the growth of the chick in the process of incubation. I then observed, that whenever an egg was hatched, the yolk (which is not diminished in the time of incubation,) was always perfectly sweet to the very last; and that part of the albumen, which is not expended on the growth of the animal, some days before hatching, was also sweet, although both were kept in a heat of 103° in the hen's egg for#»ree weeks, and in the duck's for four.

* Dr. Hunter was the first who showed callus to be endowed with the principle of life, as much as bone. 108 HUNTER ON THE BLOOD. I observed, however, that if an egg did not hatch, it became putrid in nearly the same time with any other dead animal matter; an egg, therefore, must have the power of self-preservation, or in other words, the simple principle of life. To determine how far eggs would stand other tests, to prove a living principle, I made the following experiments.* Having put a new-laid egg into a cold about 0, which froze it, I then allowed it to thaw ; from this process I imagined that the preserving powers of the egg might be destroyed.^ I next put this egg into the cold mixture, and with it one newly laid ; the difference in freezing was 1\ minutes, the fresh egg taking so much longer time in freezing. A new laid egg was put into a cold atmosphere, fluctuating between 17° and 15°; it took above half an hour to freeze; but when thawed, and put into an atmosphere at 25°, viz., nine degrees warmer, it froze in half the time: this experiment was repeated several times, with nearly the same result. To determine the comparative heat between a living and a dead egg, and also to determine whether a living egg be subject to the same laws with the more imperfect animals, I made the following experiments. A fresh egg, and one which had been frozen and thawed, were put into the cold mixture at 15°; the thawed one soon came down to 32°, and began to swell and congeal; the fresh one sunk first to 29$°, and in twenty-five minutes after the dead one it rose to 32°, and began to swell and freeze. The result of this experiment upon the fresh egg was similar to what was observed in the like experiments upon frogs, eels, snails, &c, where life allowed the heat to be diminished 2° or 3° below the freezing point, and then resisted all further decrease; but in both the powers of life were expended by this exertion, and then the parts froze like any other dead animal matter. This is not a principle peculiar to life, but is common in many other cases: it has been observed that water could be so circumstanced as to be brought below the freezing point without freezing; but just as it began to freeze it rose to 32°. In my experiments on the heat of vegetables, I observed that the sap of a tree would freeze at 32°, when taken out of the vessels; but I found the trees themselves often so low as 15°, and the sap not frozen. From these experiments, it appears that a fresh egg has the power of resisting heat, cold, and putrefaction, in a degree equal to many of the more imperfect animals, which exhibit exactly the same phenomena under the same experiments; and it is more than probable that this power arises from the same principle in both. Similar ex-

* Phil. Trans, xlviii., pp. 28, 29 ; also Ote. on certain Parts of the Animal QJconomy, 1st edit., p. 106; and the next volume of the present edition. t However this was at first not so certain; but the result of the experiment proved it was so. To be more certain of killing a part by freezing it, I believe it should be frozen very slowly, for simple freezing does not kill. GENERAL PRINCIPLES OF THE BLOOD. 109 periments have been made on the blood: after a portion of blood had been frozen, and then thawed, it has again been frozen with a similar quantity of fresh blood, drawn from the same person, and that which had undergone this process froze again much faster than the fresh blood.* As all the experiments I had made upon the freezing of animals, with a view to see whether it was possible to restore the actions of life when they were again thawed, were made upon whole animals, and as I never saw life return by thawing,f I wished to ascertain how far parts were, in this respect, similar to the whole, especially since it was asserted, and with some authority, that parts of a man may be frozen, and may afterwards recover: for this purpose I made the following experiments upon an animal of the same order with ourselves. In January, 1777, I mixed salt and ice till the cold was about 0; and on the side of the vessel containing them was a hole, through which I introduced the ear of a rabbit. To carry off the heat as fast as possible, the ear was held between two flat pieces of iron, that sunk further into the mixture than the ear; the ear remained in the mixture nearly an hour, in which time the part projecting into the vessel became stiff; when taken out, and cut into, it did not bleed; and a part being cut off by a pair of scissors, flew from between the blades like a hard chip. It soon after thawed, and began to bleed, and became very flaccid, so as to double upon itself, having lost its natural elasticity. When it had been out of the mixture nearly an hour, it became warm, and this warmth increased to a considerable degree; it also began to thieken, in consequence of inflammation ; while the other ear continued of its usual temperature. On the following day the frozen ear was still warm; and it retained its heat and thickness for many days after. About a week after this, the mixture in the vessel being the same as in the former experiment, I introduced both ears of the same rabbit through the hole, and froze them both ; the sound one however froze first, probably from its being considerably colder at the beginning, and probably, too, from its powers not being so easily excited as those of the other: when withdrawn, they both soon thawed and became warm, and the fresh ear thickened, as the other had done before. These changes in the parts do not always so quickly take place; for on repeating these experiments on the ear of another rabbit, till it became as hard as a board, it was longer in thawing than in the former experiment, and much longer before it became warm; in about two hours, however, it became a little warm, and the following day it was very warm, and thickened. In the spring, 1776, I observed that the cocks I had in thecountry had their combs smooth, with an even edge, and not so broad as

♦ Vide Corrie on the Vitality of the Blood, p. 45. | [Leeches have been frozen, and yet recovered. See note, Principles of Surgery, p. 76.] 10* 110 HUNTER ON THE BLOOD. formerly, appearing as if nearly one-half of them had been cut off. Having inquired into ihe cause of this, my servant told me that it had been common in that winter, during the hard frost. He observed that the combs had become in part dead, and, at last, had dropt off; and that the comb of one cock had dropped off entirely; this I did not see, as the cock by accident had burnt himself to death. I naturally imputed this effect to the combs having been frozen in the time of the severe frost, and having, consequently, lost their life from this cause. I endeavoured to try the solidity of this reasoning by experiment. I attempted to freeze the comb of a very large young cock (being of a considerable breadth), but could only freeze the serrated edges (which processes were fully half an inch long); for the comb itself being very thick and warm, resisted the cold. The frozen parts became white and hard, and when I cut off a little bit it did not bleed; neither did the animal show any signs of pain. I next introduced into the cold mixture one of the cock's wattles, which was very broad and thin: it froze very readily, and, upon thawing both the frozen parts of the comb and wattle, they became warm, but were of a purple colour, having lost the transparency which remained in the other parts of the comb and in the other wattle: the wound in the comb now bled freely; both comb and wattle recovered perfectly in about a month : the natural colour returned first, next to the sound parts, and increased gradually till the whole had acquired a healthy appearance. Finding that freezing both the solids and the blood did not destroy the life in either, nor the future actions depending on organization, and that it also did not prevent the blood from recovering its fluidity, I conceived the life of every part of the body to be similar: what will affect, therefore, the life of any one part, will affect also that of another, though probably not in an equal degree; for in these experiments the blood was under the same circumstances with the solids, and it retained its life ; that is to say, when the solids and blood were frozen, and afterwards thawed, they were both capable of carrying on their functions. The following experiments were made in the same manner, on living muscles, to see how far the contractions of living muscles, after having been frozen, correspond with the coagulation of the blood. A muscle removed from a frog's leg, with a portion of its tendon, was immediately placed between two pieces of lead, and exposed to a cold about ten degrees below 0. In five minutes it was taken out, when it was quite hard and white; on being gradually thawed it became shorter and thicker than while frozen; but on being irritated, did not contract; yet if at all elongated by force it contracted again, and the tendinous expansion covering the muscle was thrown into wrinkles; when the stimulus of death took place it became still shorter. From a straight muscle in a bullock's neck, a portion, three inches in length, was taken out immediately after the animal had been knocked down, and was exposed between two pieces of lead, to a GENERAL PRINCIPLES OF THE BLOOD. Ill cold below 0, for fourteen minutes : at the end of this time it was found to be frozen exceedingly hard, was become white, and was now only two inches long: it was thawed gradually, and in about six hours after thawing it contracted so as only to measure one inch in length; but irritation did not produce any sensible motion in the fibres. Here, then, were the juices of muscles frozen, so as to prevent all power of contraction in their fibres, without destroying their life; for when thawed, they showed the same life which they had before; this is exactly similar to the freezing of blood too fast for its coagulation, which, when thawed, does afterwards coagulate, as it depends in each on the life of the part not being destroyed. I took notice in the history of the coagulation of the lymph, that heat of 120° excited this action in that fluid: to see how far muscular contraction was similar in this respect, I made the following experiment.* As soon as the skin could be removed from a sheep that was newly killed, a square piece of muscle was cut off, which was after wards divided into three pieces, in the direction of fibres: each piece was put into a basin of water, the water in each basin being of different temperatures, viz., one 125°, about 27° warmer than the animal; another 98°, the heat of the animal; and the third 55°, about 43° colder than the animal. The muscle in the water heated to 125°, contracted directly, so as to be half an inch shorter than the other two, and was hard and stiff. The muscle in the water heated to 98°; after six minutes, began to contract and grow stiff; at the end of twenty minutes it was nearly, though not quite, as short and hard as the above. The muscle in the water heated to 55°; after fifteen minutes, began to shorten and grow hard; after twenty minutes it was nearly as short and as hard as that in the water heated to 98°. At the end of twenty-four hours they were all found to be of the same length and stiffness. Here, then, is also a similarity in the excitements of coagulation in the blood, and of contraction in muscles, both apparently depending on the same principle, namely, life.f If it should still be difficult to conceive how a body in a fluid state, whose parts are in constant motion upon one another,always shifting their situation with respect to themselves and the body, and which may lose a portion without affecting itself or the body, can possibly be alive, let us see if it is also difficult to conceive that a body may be so compounded as to make a perfect whole of itself, having no parts dissimilar, and having the same properties in a small quantity as in a great. Under those circumstances, the removing a portion is not taking away a constituent part, upon which the whole depends, or by which it is made a whole, but is only taking away a portion of the whole, the remaining portion being equal in quality to the whole, and in this respect is similar to the reducing

* Vide Phil. Trans., lxvi., p. 412, Paper on Drowning; also, Obs. on certain parts of the Animal G3conomy, in the succeeding volume of this edition. f The application of this principle in disease I shall not at present take notice of. 112 HUNTER ON THE BLOOD. a whole of anything. This might be perfectly illustrated, without straining the imagination, by considering the operation of union by the first intention. Union by the first intention is an im« mediate sympathetic harmony between divided parts when brought simply into contact, which I call contiguous sympathy. In this case it is not necessary that the very same parts should oppose each other, else harmony, and consequently union, could never take place; it is simply necessary that the two parts be alive, and they might be shifted from one sort of a living creature to another for ever, without any injury to either, or without exciting irritation, and the whole would still be as perfect as ever. Neither can the motion of one living part upon another affect the body, because all its parts are similar, and in harmony with each other. It is exactly the same with the blood,for neither its motion on itself, nor its motion on the body, can either affect it or the body, since all the parts are similar among themselves. This is the case with all matter, where the property does not depend upon structure, or configuration, but upon the compound ; for water is still water, whether its parts are moving on each other, or at rest; and a small portion has the same property with the whole, and is in fact a smaller whole. One of the great proofs that the blood possesses life depend on the circumstances affecting its coagulation; and, at present, we are only to explain the principles upon which these are founded, which it will be in some degree necessary to recapitulate; but perhaps the strongest conviction on the mind will arise from the application of this principle to diseases, especially inflammation. While the blood is circulating it is subject to certain laws to which it is not subject when not circulating. It has the power of preserving its fluidity, which was taken notice of when treating of its coagulation; or, in other words, the living principle in the body has the power of preserving it in this state. This is not produced by motion alone, for in the colder animals, when almost in a state of death during the winter, when their blood is moving with extreme slowness, and would appear to preserve simply animal life through the whole body, and keep up that dependence which exists between the blood and the body already formed, the blood does not coagulate to accomplish these purposes. If the blood had not the living principle, it would be, in respect of the body, as an extraneous substance. Blood is not only alive itself, but is the support of life in every part of the body; for mortification immediately follows when the circulation is cut off from any part, which is no more than death taking place in the part, from the want of the successive changes of fresh blood. This shows that no part of the body is to be considered as a complete living substance, producing and continuing mere life, without the blood; so that blood makes one part of the compound, without which life would neither begin nor be continued.* This circum-

+ [The form of the argument is here changed from mere passive life to life such as it exists in completely organized bodies, where it always is active, and where, consequently, as it is quaintly enough expressed in the text, its continu- GENERAL PRINCIPLES OF THE BLOOD. 113

stance, on its first appearance, would seem a little extraordinary, when we consider that a part, or the whole, are completely formed in themselves, and have their nerves going to them, which are supposed to give animal life; yet that perfect living part, or whole, shall die in a little time, by simply preventing the blood from moving through the vessels: under this idea, it is not clear to me whether the blood dies sooner without the body, or the body without the blood. Life, then, is preserved by the compound of the two, and an animal is not perfect without the blood: but this alone is not sufficient, for the blood itself must be kept alive; because while it is supporting life in the solids, it is either losing its own, or is rendered incapable of supporting that of the body. To accomplish all this it must have motion, and that in a circle, as it is a continuance of the same blood which circulates, in which circle it is in one view supersaturated, as it were, with living powers, and in another is deficient, having parted with them while it visited the different parts of the body. Life is, in some degree, in proportion to this motion, either stronger or weaker, so that the motion of the blood may be reckoned, in some degree, a first moving power; and not only is the blood alive in itself, but seems to carry life everywhere ; however, it is not simply the motion, but it is that which arises out of, or in consequence of, the motion. Here, then, would appear to be three parts, viz., body, blood, and motion, which latter preserves the living union between the other two, or the life in both. These three make up a complete body, out of which arises a principle of self-motion, a motion totally spent upon the machine, or which may be said to move in a circle, for the support of the whole; for the body dies without the motion of the blood upon it, and the blood dies without the motion of the body upon it; perhaps pretty nearly in equal times. So far, I have considered the blood when compounded with the body and motion, in which we find it preserves its fluidity, and continues life in the body; but fluidity is only necessary for its motion to convey life, and the continuance of life is probably owing to its being coagulated, and becoming a solid ; or at least the support of the body is owing to this cause. For this, however, it requires rest, either by extravasation, or by being retained in the vessels till the utility of circulating is lost; or till it can answer some good purpose by its coagulation, as in mortification. Under any of these circumstances it becomes a solid body ; for the moment it is at rest it begins to form itself into a solid, and changes into

ance seems to be the result of "body, blood, and motion." I apprehend, however, the real line of argument to be, to prove that the blood and the solids possess life independently of each other,—not to make it the result of a compound of the two. It might be, and has been, with full as much propriety argued that the life of the blood is derived from the vessels, as that the life of the body is derived from the blood, for neither can continue without the other. The life of the blood is soon lost out of the body, and the body soon dies without the blood: nevertheless, a residual and independent vitality seems to reside in both for a limited space after they are separated from each other.] 114 HUNTER ON THE BLOOD. this or that particular kind of substance, according to the stimulus of the surrounding parts which excites this coagulum into action, and makes it form within itself, blood, vessels, nerves, etc. The coagulation is the first step towards its utility in the constitution, and this arises from its living principle; for if that principle be destroyed, it does not coagulate at all, that is, naturally, for I do not here speak of any chemical coagulation. I shall now endeavour to prove that the coagulation of the coagulating lymph bears some analogy to the actions of muscles, which we know to depend upon life, and which affords one of the strongest proofs of the existence of this principle; and though the action of coagulation itself be not similar to the actions of muscles, yet, if we can show that they are governed by the same laws, we may reasonably conclude that the first principle is the same in both. When I was treating of the coagulation of the lymph, I took notice that cold did not cause it, and supported the opinion by several experiments; at the same time I mentioned an experiment of Mr. Hewson, to prove the same thing, and which he conceived to be conclusive, but which does not appear to me in any way to affect his hypothesis (p. 34). This experiment I had often made, but with another view, viz., to illustrate the living principle of the blood, which to me it in some measure does, more especially when compared with similar experiments on living muscles. As the coagulation of the blood is a natural process, and as all natural processes have their time of action, unless influenced by some exciting cause, and since cold is not a cause of the blood's coagulation, even when removed out of the circulation, the blood may be frozen much more quickly than it can coagulate, by which change its coagulating power is suspended. To prove this by experiment, I took a thin leaden vessel with a flat bottom, of some width, and put it into a cold mixture below 0, and allowed as much blood to run from a vein into it as covered its bottom. The blood froze immediately; and when thawed became fluid, and coagulated, I believe, as soon as it would have done had it not been frozen. As the coagulation of the blood appears to be that process which may be.compared with the action of life in the solids, we shall examine this property a little further, and see if this power of coagulation can be destroyed: if it can, we shall next inquire if, by the same means, life is destroyed in the solids, and if the phenomena are nearly the same in both. The prevention of coagulation may be effected by electricity, and often is by lightning: it takes place in some deaths, and is produced in some of the natural operations of the body; all of which I shall now consider. Animals killed by lightning, and also by electricity, have not their muscles contracted; this arises from death being instantaneously produced in the muscles, which therefore cannot be affected by any stimulus, nor consequently by the stimulus of death.* In such cases

* [These sort of expressions are evidently vague and unsatisfactory. It is a fact that muscles contract at death ; but to say that this is caused by the " stimu- GENERAL PRINCIPLES OF THE BLOOD. 115 the blood does not coagulate. Animals that are run very hard, and killed in that state, or, what produces a still greater effect, are run to death, have neither their muscles contracted nor their blood coagulated; and in both respects the effect is in proportion to the cause.* I had two deer run till they dropped down and died: in neither did I find the muscles contracted nor the blood coagulated.f In many kinds of death we find that the muscles neither contract nor the blood coagulate. In some cases the muscles will contract while the blood continues fluid, in some the contrary happens, and in others the blood will only coagulate to the consistence of cream. Blows on the stomach kill immediately, and the muscles do not contract, nor does the blood coagulate. Such deaths as prevent the contraction of the muscles or the coagulation of the blood, are, I believe, always sudden. Death from sudden gusts of passion is of this kind; and in all these cases the body soon putrefies after death. In many diseases, if accurately attended to, we find this correspondence between muscles and blood; for where there is strong action going on, the muscles contract strongly after death, and the blood coagulates strongly. It is unnecessary, I imagine, to relate particular instances of the effects of each of these causes; I need only mention that I have seen them all. In a natural evacuation of blood, viz., menstruation, it is neither similar to blood taken from a vein of the same person, nor to that which is exlravasted by an accident in any other part of the body, but is a species of blood changed, separated, or thrown off from the common mass by an action of the vessels of the uterus, similar to that of secretion; by which action the blood loses the principle of coagulation, and I suppose life (p. 42). The natural deduction from all these facts and observations I think is perfectly easy; it is impossible to miss it. This living principle in the blood, which I have endeavoured to show to be similar in its effects to the living principle in the solids, owes its existence to the same matter which belongs to the other, and is the materia vitae diffusa, of which every part of an animal

lus of death" adds nothing to our knowledge of the fact. It is the ascription of a negative cause, and serves but to cover our ignorance of the real cause with the cloak of a name, and that name a bad one. See p. 40, note*; and Principles of Surgery, p. 32, note."] * This is the reason why hunted animals are commonly more tender than those that are shot. f [Brisk exercise rather tends to accelerate coagulation (Mm/a's Physiology, p. 38 ; Prater on the Blood, p. 94), although, if carried to the point of exhaustion, this effect is altogether prevented ; that is, according to the physiological hypothesis, the stimulus of exercise, by being in excess, becomes a sedative. It is to be observed, however, that the clot, although it forms more rapidly, contracts less, both in extent and duration, than under ordinary circumstances, and runs more rapidly into putrefaction. But muscular contraction is obedient to precisely the same laws, and hence the argument for the analogy of these phenomena, and that coagulation must consequently be a vital process.] 116 HUNTER ON THE BLOOD. has its portion:* it is, as it were, diffused through the whole solids and fluids, making a necessary constituent part of thern, and forming with them a perfect whole; giving to both the power of preservation, and the susceptibility of impression, and, from their construction, giving them consequent reciprocal action. This is the matter which principally composes the brain; and where there is a brain, there must necessarily be parts to connect it with the rest of the body, which are the nerves; and as the use of the nerves is to continue, and therefore convey, the impression or action of the one to the other, these parts of communication must necessarily be of the same matter; for any other matter could not continue the same action. From this it maybe understood that nothing material is conveyed from the brain by the nerves, nor, vice versd, from the body to the brain; for if that was exactly the case, it would not be necessary for the nerves to be of the same materials with the brain; but as we find the nerves of the same materials, it is a presumptive proof that they only continue the same action which they receive at either end. The blood has as much the materia vitas as the solids, which keeps up that harmony between them; and as every part endued with this principle has a sympathetic affection upon simple contact, so as to affect each other, (which I have called contiguous sympathy,) so the blood and the body are capable of affecting and being affected by each other; which accounts for that reciprocal influence which each has on the other. The blood being evidently composed of the same matarials with the body, being endued with the same living powers, but from its unsettled state having no communication with the brain, is one of the strongest proofs of the materia vitte making part of the composition of the body, independently of the nerves, and is similar in this respect to those inferior orders of animals that have no nerves, where every other principle of the animal is diffused through the whole.f This opinion cannot be

* I consider that something similar to the •materials of the brain is diffused through the body, and even contained in the blood; between this and the brain a communication is kept up by the nerves. I have, therefore, adopted terms explanatory of this theory ; calling the brain the materia vitae coacervata; the nerves, the chordae internuncios; and that diffused through the body, the materia vitae diffusa. t [Thus no rnuscular fibres have yet been detected in the homogeneous parenchyma of the freshwater Polype, the Medusa, and several other species of zoophytes, although a species of contractility plainly resides in every part of these animals. In the Acrita there are no distinct nervous filaments; the digestive organ is excavated in the parenchyma of the body, and is devoid of distinci parietes; the vascular system consists merely of reticulate canals, in the substance of the body, devoid of proper tunics, in which a cyclosis of the nutrient fluids is observed, analogous to that of plants, but not a true circulation; and generation is accomplished by spontaneous fission, or gemmation. All the different systems, in short, are blended together in these polymorphous animals, analogous to what occurs in the ova or germs of the higher classes ; and where even a distinct organ happens to be eliminated, it is often repeated indefinitely in the same individual, GENERAL PRINCIPLES OF THE BLOOD. 117 proved by experiment; but I think daily experience shows us that the living principle in the body acts exactly upon the same principle with the brain. Every part of the body is susceptible of impression, and the materia vitae of every part is thrown into action, which, if continued to the brain, produces sensation; but it [the materia vitas] may only be such as to throw the part impressed into such actions as it is capable of, according to the kind of impression; so does the brain or mind. The body loses, impression by habit, so does the brain; it continues action from habit, so does the brain. The body, or parts of the body, have a recollection of former impressions when impressed anew; so has the brain: but they have not spontaneous memory as the brain has, because the brain is a complete whole of itself, and therefore its actions are complete in themselves. The materia vitae of the body being diffused, makes part of the body in which it exists, and acts for this part, and probably for this part alone. The whole, taken together, hardly makes a whole, so as to constitute what might be called an organ, the action of which is always for some other purpose than itself: but this is not the case with the brain. The brain is a mass of this matter, not diffused through anything for the purpose of that thing, but constituting an organ in itself, the actions of which are for other purposes, viz., receiving, by means of the nerves, the vast variety of actions in the diffused materia vitae which arise from impression and habit, combining these, and distinguishing from what part they come. The whole of these actions form the mind, and, according to the result, react so as to impress more or less of the materia vitae of the body in return, producing in such parts consequent actions. The brain, then, depends upon the body for its impression, which is sensation, and the consequent action is that of the mind ; and the body depends upon the consequence of this intelligence, or effect of this mind, called the will, to impress it to action ; but such [sensation and action] are not spent upon itself, but are for other purposes, and are called voluntary.

as in polypi, where the nutritious tubes of one individual are generally supplied by numerous mouths, which give it the semblance of a composite animal. The Polygastrica derive their name from an analogous multiplication of their digestive organ; and in the Taeniae, each joint of the animal is the seat of a separate ovary. In these, which may be considered as the first steps of animal organization, we may observe a close resemblance to vegetables. There is no attempt or approach to centralization, but all the properties or functions of the animal (for which in the higher orders distinct organs are appropriated) are enjoyed by and reside in equally every part, and confer on every part an individuality of existence which enables it, when separated from the whole, to exist, to grow, and to reproduce as a complete animal. The knowledge of these facts by Hunter may serve to show the extent of his information on comparative anatomy, and the powers which he possessed of generalization; but I look upon it as a still higher proof of the activity of his genius, to have applied so unexpected a truth to the illustration of the life of the blood. In the ensuing note I shall have occasion to notice the error into which many physiologists have fallen in expounding this part of Mr. Himter's doctrines. See note, Principles of Surgery, p. 51; and Cyclop, of Anal, and Phys. art. Acrita.] 11 118 HUNTER ON THE BLOOD. But mere composition of matter does not give life; for the dead body has all the composition it ever had. Life is a property we do not understand; we can only see the necessary leading steps towards it. If nerves, either of themselves or from their connexion with the brain, gave vitality to our solids, how should a solid continue life after a nerve is destroyed 1 or, still more, when paralytic 1 for the part continues to be nourished, although not to the same full health as where voluntary action exists: and this nourishment is the blood; for deprive it of the blood, and it mortifies. The uterus, in the time of pregnancy, increases in substance and size, probably fifty times beyond what" it naturally is; and this increase is made up of living animal matter, which is capable«of action within itself. I think we may suppose its action more than double; for the action of every individual part of this viscus, at this period, is much increased, even beyond its increase of size, and yet we find that the nerves of this part are not in the smallest degree increased. This shows that, tlie nerves and brain have nothing to do with the actions of a part, while the vessels whose uses are evident increase in proportion to the increased size: if the same had taken place with the nerves, we should have reasoned from analogy. It is probably impossible to say where the living principle first begins in the blood; whether in the chyle itself, or not till that fluid mixes with the. other blood, and receives its influence from the lungs. I am, however, rather inclined to think that the chyle is itself alive; for we find it coagulates when extravasated; it has the same powers of separation with the blood; and it acquires its power of action in the lungs as the venal blood does [p. 71, note]. I conceive this [viz., the action of the air on the chyle] to be similar to the influence of the male and female on an egg, which requires air and a due warmth to produce the principle of action in it, and somewhat similar to the venal blood coming to the lungs to receive new powers, which it communicates to the body. To endeavour to prove whether the chyle had the power of action in itself, similar to the blood, I made the following experiment. I opened the abdomen of a dog, and punctured one of the largest lacteals at the root of the mesentery, out of which flowed a good deal of chyle. I then allowed this part to come in contact with another part of the mesentery, to see if they would unite, as extravasated blood does ; but they did not. However, this experiment, though performed twice, is not conclusive; for similar experiments with blood might not have succeeded. From what has been said with regard to the blood, that it becomes a solid when extravasated in the body, we must suppose that some material purpose is answered by it; for if the blood could only have been of use in a fluid state, its solidity would not have been so much an object with nature. It appears to me to be evident that its fluidity is only intended for its motion, and its motion is only GENERAL PRINCIPLES OF THE BLOOD. 119 to convey life and living materials to every part of the body. These materials, when carried, become solid; so that solidity is the ultimate end of the blood, as blood. The blood, when it naturally increases the body or repairs a part, may be said to be extravasated, although it is not commonly so considered: what is usually understood by extravasation is when blood is effused from some accident, or from disease in the vessels, when of course it becomes obvious to the sight; but even this extravasation is of use, by the blood coagulating, although too often it is in too large a quantity. Accident docs not calculate the size of the vessel ruptured to be just equal to the effect wanted by the rupture ; but nature has made a wise provision for this overplus. As extravasation arises from a rupture of a vessel, it is of service in the reunion of that vessel: if there are more solids ruptured than a vessel, as in a fracture of a bone, it becomes a bond of union to those parts; and this maybe called union by the first intention: but the union is not that of the two parts to each other, but the union of the broken parts to the intermediate extravasated blood; so that it is the blood and parts uniting which constitutes the union by the first intention. This blood, so extravasated, either forms vessels in itself, or vessels shoot out from the original surface of contact into it, forming an elongation of themselves, as we have reason to suppose they do in granulations. I have reason, however, to believe that the coagulum has the power, under necessary circumstances, to form vessels in and of itself; for I have already observed, that coagulation, although not organic, is still of a peculiar form, structure, or arrangement, so as to take on necessary action, which I should suppose is somewhat similar to muscular action. I think I have been able to inject what I suspected to be the beginning of a vascular formation in a coagulum, when it could not derive any vessels from the surrounding parts. By injecting the crural artery of a stump, above the knee, where there was a small pyramidal coagur lum, I have filled this coagulum with my injection, as if it had been cellular; but there was no regular structure of vessels. When I compare this appearance with that of many violent inflammations on surfaces where the red blood is extravasated, forming, as it were, specks of extravasation like stars, and which, when injected, produce the s:ime appearance with what I have described in the injection of the coagulum; when I compare these again with the progress of vascularity in the membranes of the chick; where one can perceive a zone of specks beyond the surface of regular vessels close to the chick, similar to the above extravasation, and which in a few hours become vascular, I conceive that these parts have a power of forming vessels within themselves, all of them acting upon the same principle. But where this coagulum can form an immediate union with the surrounding parts, it either receives vessels at this surface, or forms vessels first at this union, which communicate with those of the surrounding surface; and they either shoot deeper and deeper, 120 HUNTER ON THE BLOOD. or form vessels deeper and deeper, in the coagulum, till they all meet in its centre. If it is by the first mode, viz., the shooting of vessels from the surrounding surfaces into the coagulum, then it may be the ruptured vessels, in cases of accident, which shoot into the coagulum; and where a coagulum, or extravasation of coagulable lymph, is thrown in between two [sound] surfaces only contiguous, there it may be the exhaling vessels of those surfaces which now become the vessels of the part. In whatever way they meet in the centre, they instantly embrace, unite, or inosculate. Now this is all perfectly and easily conceived among living parts, but not otherwise. As the coagulum, whether wholly blood or coagulating lymph alone, has the materia vitas in its composition, which is the cause of all the above actions, it soon opens a communication with the mind, forming within itself nerves. Nerves have not the power of forming themselves into longer chords, as we conceive vessels to have ; for we know that in the union of a cut nerve, where a piece has been taken out, it is by means of the blood forming a union of coagulum, and that the coagulum gradually becomes more and more of the texture, and has, of course, more and more the use, of a nerve, somewhat similar to the gradual change of blood into a bone in fractures. It would appear, then, that the blood is subservient to two purposes in an animal: the one is the support of the matter of the body when formed, the other is the support of the different actions of the body.*

*[On Life.—Although it would be foreign to the object of these notes to enter into a lengthened discussion on the nature cf life in general, I shall, I trust, need no apology for presenting the reader with a condensed view of Mr. Hunter's opinions on the subject, since by so doing I shall furnish him with the means of more clearly comprehending the nature, and more exactly estimating the value of the arguments adduced by the author in support of his peculiar views respecting the life of the blood. Mr. Hunter had a great dislike to definitions, for, said he, a definition allows one " to bring together a thousand things that have not the least connexion with it;" and for this reason probably he has abstained from setting forth, in the shape of a formal definition, his notions of life in the abstract. As it is necessary, however, when speaking of life, to fix on at least some of its essential properties by which to recognise its presence or absence, I shall take as a definition a short statement Mr. Hunter has made in his lectures, Principles of Surgery, p. 21, of what he calls the most simple ideas of life. 1. '-The first and most simple idea of life," says he, " is its being the principle of self-preservation." 2. " The second is its being the principle of action," or, as he has elsewhere stated it, "the susceptibility to impression, with a consequent power of action." "These are two very different properties, though arising from the same principle," and will require separate consideration. I. Of the principle of self-preservation.—"By the living principle," says Mr. Hunter, " I mean to express that principle which prevents matter from falling into dissolution,—resisting heat, cold, and putrefaction.....I have asserted that life simply is the principle of preservation, preserving it from putrefaction." Bodies belonging to the animal and vegetable kingdoms, considered as mere chemical compounds, must, from the energetic affinities of their component elements, be exceedingly prone to spontaneous decomposition; nevertheless, we find GENERAL PRINCIPLES OF THE BLOOD. 121 § 7. Some unconnected Experiments respecting the Blood.

The following experiments have rather been imagined than fully executed, and the subject is rather broached and touched upon than

them, when in a living state, existing unchanged, often for a great length of time, although placed under external influences the most favourable for the operation of these affinities. Thus, seeds retain their vitality for years, if not for centuries, when buried deep in the soil; during the process of incubation, the yolk, and also a part of the albumen, of the egg, remain perfectly sweet to the last, though subjected from three to four weeks to a temperature of 103°; or, on the other hand, a fresh egg will resist the influence of a freezing mixture considerably longer than an egg the vitality of which has been destroyed by previous freezing, and, as in the case of some of the inferior animals, it will not allow its temperature to be reduced more than two or three degrees below the freezing-point, until the powers of life are exhausted, when it congeals, and assumes the temperature of the surrounding medium. Again, animals will exist and grow in the stomach, resisting the powers of digestion as long as they live ; but where, as their vitality ceases, they are immediately digested. What, then, is it that confers on animal and vegetable substances this power of resistance to the influence of external agents tending to their destruction! The theory which Mr. Hunter maintains is, that life is a simple principle, superadded to the common properties of matter in these bodies. " Animal and vegetable substances," says he, " differs from common matter, in having a power superadded totally different from any other known property of matter, out of which arise various new properties: it cannot arise out of any peculiar modification of matter, but appears to be something superadded......Mere composition of matter does not give life, for the dead body has all the composition it ever had, .....This principle exists in animal substances devoid of apparent organization. and motion......Organization and life do not depend the least on each other;" or rather, are not necessarily connected. " Organization may arise out of living parts, and produce action; but life can never arise out of, or depend on, organization......Organization and life are two different things." This opinion respecting life in its most simple form seems, from the frequency and explicitness with which it is announced, and from its being that which he adopted in his work on Inflammation, to be the opinion which Mr. Hunter considered as most probably true. We do, however, find him here and there propounding views somewhat at variance with the above; but this arose probably from the habit of always keeping his mind open to conviction; or from an unwillingness to bind himself to any opinions which did not rest on the most unequivocal proofs, rather than from his considering these as affording more satisfactory explanations of the phenomena of life than the former. first, he seems to have had some doubts whether life might not be regarded as an effect of the arrangement of the ultimate molecules of matter, as distinguished from organization of a more apparent kind. " Life, then, appears to be something superadded to this peculiar modification of matter; or this modification of matter is so arranged, that the principle of life arises out of the arrangement; and this peculiar disposition of parts may be destroyed, and still the modification from which it is called animal matter remain the same. If the latter be the true explanation, this arrangement of parts on which life should depend would not be that position of parts necessary to the formation of a whole part, or an organ, for that is probably a mechanical, or at least an organical arrangement; but just a peculiar arrangement of the most simple particles, giving rise to a principle of preservation .... the arrangement for preservation, which is life, becomes the principle of action, not the power of action.....We have hitherto traced animal matter from its change from common matter to animal matter, the particles of which have possessed such an arrangement as to produce life." It must, I think, be conceded, that such an arrangement of the ultimate mo-. 11* 122 HUNTER ON THE BLOOD. prosecuted : but as I have not time at present to go through with the experiments, so as to arrive at some general result, I thought it

lecules as is above alluded to, may exist even in those forms of nnimal and vegetable matter which, to our limited powers of observation, appear to possess no traces of organization, as the albumen and yolk ofan egg ; and Jurther, that those phenomena of life which are perceptible to our senses, may be necessarily connected with, nay, dependent on, such an arrangement. But even this admission only carries us back one step further, namely, to inquire what is the agent or cause, under the influence of which this arrangement of molecules is effected and preserved * Is it one of those agents under the control of which the arrangements and changes in unorganized matter are effected, as attraction, galvanism, &c; or is it a principle distinct from these] Now it is evident that here our reason is at fault, and will not enable us to reply conclusively to this question, since neither the cause itself, nor the first links in the chain of effects, supposing the above notion of a peculiar arrangement of ultimate particles be correct, arc within the reach of our observation. We want data, and therefore we must be content to limit our inquiries to the more obvious phenomena of life; to examine its laws and moJes of action, and to ascertain how far these coincide with those of the other agents above mentioned. If we adopt this course,—and it is the only one by which we can hope to arrive at a solution of the problem,—we shall, I think, be obliged to admit the existence of some principle or agent distinct from those which govern unorganized bodies. In these we rind nothing analogous to the vital phenomena of irritability, contractility, the nervous influence, &c, not to mention that a broad line of distinction seems also to exist in regard to the chemical composition, intimate structure, mode of growth, form, duration, &c., of these two classes of bodies. These marks of distinction are broad and obvious, and should make us careful in admitting the identity of the causes by which they are produced with others of which the effects are so very dissimilar, merely on the ground of some hastily admitted analogy. We are by no means to abstain from inquiring how far the ordinary laws of matter are employed in producing effects in organized bodies ; but we should at the same time be prepared, when these laws will not account for the phenomena observed, to admit the influence of another agent, the vital principle, the laws of which are to be patiently sought out and understood before we undertake to decide on its identity with other and apparently dissimilar agents. In reference to this subject, Mr. Hunter was accustomed to employ the illustration of magnetism, which may be generated by holding a bar of iron at a particular angle with the horizon. " A bar of iron without magnetism may be considered like animal matter without life; set it upright, and it acquires a new property of attraction and repulsion at its different ends. Now is this any substance added 1 or is it a certain change which takes place in the arrangement of the particles of iron giving it this property 1" I apprehend that no one will be disposed to object to this illustration as a simple help to apprehension, however unphilosophical it may be to extend the parallelism to its utmost limits, as Mr. Abernethy has done with respect to electricity. I have met with nothing in Mr. Hunter's published or posthumous writings which warrants, or in the leabt degree countenances, the opinion that these principles are identifiable; the analogy is wholly fallacious ; nor is there, so far as I am aware, any single instance in which the principle ofelectricity has ever produced the proper and genuine effects of the principle of life. It has I know been asserted by Dr. Wilson Philip (Exper. Inquiry, 2d edit., p. 246), that galvanism performs all the functions of the nervous influence; that it excites the muscles; that it effects the secretions of the stomach ; and that it occasions the evolution of caloric; but it may be replied, 1st, that many other stimuli affect the muscles besides galvanism; 2d, that digestion is not materially affected when the eighth pair of nerves is divided on the oesophagus; and 3d, that the phenomena of animal heat are more easily explicable on chemical principles. Dr. Alison (Physiology, 2d edit,, p. 116 et seq.) has fully and in my opinion most GENERAL PRINCIPLES OF THE BLOOD. 123

better to bring forward what, in my opinion, should be done, than to omit the subject altogether.*

* Many of these experiments were repeated, by my desire, by Dr. Physick, now of Philadelphia, when he acted as house-surgeon at St. George's Hospital, whose accuracy I could depend upon. satisfactorily refuted this doctrine, to the support of which the name and authority of Hunter have been most unwarrantably adduced. Secondly, the existence of the living principle is ascribed to the materia vita diffusa, " of which every part of an animal has its portion ; i. e., something similar to the brain diffused through the whole solids and fluids, making a necessary constituent part of them, and forming with them a perfect whole, giving to both the power of preservation, &c.;" but this, I apprehend, is not to be taken literally, for, "as the brain and nerves are composed of animal matter, and as that animal matter has life, or the first principle of action in common with all the other matter composing the whole body," it must be evident that the author did not mean to identify the living principle with a tangible material substance ; I presume his meaning to be simply that something corresponding to cerebral matter is diffused through all living substances, and serves as the intermedium by which the sympathy of living parts is maintained. This is rendered probable by what has been said in the previous note; but to suppose that he considered this cerebral matter as identical with life, is totally irreconcilable with the supposition formerly made, of a superadded principle. Every part, then, whether organized or unorganized, solid or fluid, "where there exists simply the power of preservation," is supposed to possess this simple principle of life. It is on this principle that the horticulturist performs the operation of grafting; that the testicles of a cock may be made to grow in the belly of alien, and a man's tooth in the comb of a cock. It must be evident that the detached parts would, if not alive, act as foreign substances in these cases, and stimulate the living parts to throw them off. Perhaps the most striking proof that life is not a mere emanation from the brain, or any other individual centre, but inheres in every part, is to be found in the irritability of muscles when separated from the body after death. In warm-blooded animals this does not last many minutes, but it endures for a long time in cold-blooded animals. Thus, according to Sir B. Brodie, " the head of a turtle was still alive, and bit at objects which were presented to it, many hours after it had been separated from the trunk;" and " the heart of a sturgeon, inflated from the mouth and hung up to dry, pulsated regularly for ten hours, the auricles continuing their action even when so dry as actually to create a rustling noise.....Oxygen, hydrogen, carbonic acid, and nitrogen, produced the same effect on the heart of a snapper." (Mitchell in Amer. Journ., vii. 53.) " The living principle [therefore] is essential to every part, and is as much the property of it as gravity is of every particle of matter composing a whole.....Every individual particle of the living body, then, is possessed of life, and the least imaginable part which we can separate is as much alive as the whole." But it by no means follows, because every particular part of the body possesses a principle of life independent of the effect which arises from their union as one system, that therefore this principle is independent of matter. We can with difficulty conceive of any of the powers of matter apart from, and independent of, the substances in which they reside; although, from the manner in which heat, electricity, magnetism, &c, are capable of being transferred from one substance to another, we conventionally agree to speak of these agencies as independent substances, or at least as superadded principles. Blumenbach supposes every living particle to be endowed with a formative principle (nisus formativus), as contradistinguished from the peculiar mode of life (vita propria) enjoyed by each organ or structure. The former is the same in all parts, and in that energy by which, under different modifications, nutrition, 124 HUNTER ON THE BLOOD. I wished to see if blood that coagulated with an inflammatory crust putrefied later than that which coagulated without it; fori

reparation, and generation, are accomplished; the latter is peculiar to each part, and is that by virtue of which, concurring with other parts, the complex phenomenon of systemic life is preserved (uber den Bildungstneb, &.c). 1 his appears to me to be only another mode of expressing what was meant by Hunter, who says, that "although life may appear very compounded in its effects in a complicated animal like man, it is as simple in him as in the most simple animal, and is reducible to one single property in every animal." The resistance to putrefaction which arises from the possession^! the principle of life, and which, in fact, is the only genuine indication of its presence in many cases, is not, as Richerand supposes, a " secondary effect, depending on the exercise of the functions," because function presupposes organization, but proceeds from a simple principle of antagonism, just as gravity resists force, or one chemical affinity is balanced by another. I am speaking here only of the most simple substances; for in completely organized bodies the resistance which La opposed to external agencies is undoubtedly to be regarded as a phenomenon of a mixed kind. Life, then, according to this first and most simple idea of it, consists in a property of matter superadded to and different from all other known agencies, whereby substances otherwise extremely prone to be acted upon by external causes are enabled to preserve themselves from dissolution. It exists independently of visible organization and spontaneous motion, and it inheres more or less in every living part, although not perhaps always in every part in equal intensity. Of its nature or immediate proximate cause we are entirely ignorant, except that a peculiar chemical and perhaps organical constitution of bodies always accompanies it, which may be either its cause or its effect, or a collateral effect of the same cause; but at present we are compelled to regard it as an ultimate fact. Ii. The principle of action, or susceptibility to impression and consequent power of action.—"It was not sufficient that animal matter should be endowed with this first principle of self-preservation; it was necessary that it should have action or motion within itself. This does not necessarily arise out of the arrangement for preservation. On the other hand, the arrangement for preservation, which is life, becomes the principle of action, not the power of action; for the power of action is a step further. The power of action must arise from a particular formation of those living parts; for before action can take place, the matter must be arranged with this view. This is generally effected by the union of two or more living parts, so united as to allow of motion on each other, which motion the principle of action is capable of effecting when so disposed." The impressions and actions thence ensuing will vary infinitely amongst themselves, according to the complexity of the organization, " producing thereby infinite variety, both in all natural and diseased acts." Now incitability and the power of acting under stimuli are the common fundamental properties of all organized beings, and of all the, parts of those beings; but these qualities are differently designated, according to the different tissues in which they are manifested : irritability in muscles, sensibility in nerves, contractility in membranes, and so forth. This state of receptivity and action are carefully however to be distinguished from that power on which these qualities depend, viz., the vital principle, of which we know nothing except from its effects. " Life is a property we do not understand: we only see the necessary steps leading to it." But although "life is not action," yet " it is continued and supported by it when it takes place. Action creates a necessity of support, and furnishes it It is not necessary that action should continue in all parts; in some it is necessary that the principle or power of action should be continued, but in others it is necessary that action should take place even for the preservation of the power of action." r Such are the leading outlines, as they appear to me, of Mr. Hunter's doctrines GENERAL PRINCIPLES OF THE BLOOD. 125 conceived that the strength of coagulation was something similar to the strength of contraction in a muscle, resisting putrefaction. For this purpose I ordered the following experiments to be made.

of life: according to which it would appear that the principle of life may exist both in a passive and in an active state; in a passive state generally only where there is no apparent organization, but in an active state wherever organization is developed. It has been considered by several modern physiologists, that as we are entirely ignorant of the nature of life, we ought to reject all such expressions as principle of life, vital principle, &c, as vague and indeterminate abstractions; but surely the same grounds exist for banishing the term principle altogether from our vocabularies. In the analysis of complex phenomena we ascend to ultimate facts, for which we assign some unknown causes, differently denominated forces, principles, or powers of matter, which have been likened to the unknown algebraical quantities x and y; and the determination of the laws by which these operate, constitute the sole business of the philosopher. I do not, therefore, agree in the following observation of Magendie: " De Routes les illusions dans lesquelles sont tombes quelques physiologiste3 modernes, l'une des plus deplorables est d'avoir cms, en forgeant un mot principe vital, on force vitale, avoir fait quelque chose d'analogue a la de"couverte de la pesanteur universelle*' (Physiologie, p. 14); but rather in the remark of Prout, " that it is absolutely necessary to assume the existence of some agency different from and superior to that which operates among inorganic matters" (Bridgewater Treatise, p. 442), whether this agency bo called life, the principle of life, or merely organic agencies. The circumstances under which this principle is usually manifested are infinitely complicated, arising partly from the reaction of the different parts on each other, and partly from the introduction into the living organism of most of those powers which operate on inorganic bodies, which the principle of life has the power more or less of modifying and counteracting, in subserviency to its own purposes. The animal body may be regarded as an intricate piece of machinery, arranged in perfect accordancy with the preexisting properties of matter, so as to admit of the agency of those properties for the accomplishment of its own ends: thus we see various apparatuses, as the eye, the ear, the heart, the joints, &c, contrived in perfect conformity with the laws of light, of sound, of fluids, and of force. Gravity is still gravity in organized as well as in unorganized bodies ; and the phenomena of endosmose and exosmose, of evaporation, elasticity, imbibition, and chemical affinity, plainly evince that these properties exist as well in living as in dead bodies, and even enter as essential elements into all the vital and most important functions of the body. Physiology, in short, is a complex science, presenting phenomena which proceed from the combined operation of chemical, physical, and vital agencies, harmoniously intermixed, but in which the vital principle holds a sort of supremacy, directing and modifying all the subordinate agencies to its own definite ends, besides producing effects which are not referable to any other power. It seems, however, as Sir E. Home observes, " to be a rule of the animal ceconomy, that the laws of life should not be employed when the mechanical or chemical laws of matter will answer the purpose." (Led. on Comp. Anat., v. 477.) Having admitted the possibility of the self-organization of blood and coagulable lymph, it appears to me that Hunter has not been quite consistent in limiting his notion of action so strictly as he has done. He speaks as if action could only take place in parts visibly organized, as, for instance, in the muscles; but we know that action does and must commence in the egg, where no previous organization of parts has existed, and therefore necessarily precedes organization; somewhat, perhaps, as crystals are seen to gather in a fluid evaporating under the microscope. It may perhaps be replied, that the albumen and yolk of the egg are imperfectly organized, inasmuch as they exhibit evident traces of stratification and a granular arrangement after they are boiled, just in the same manner as'the crystalline lens of the eye: this latter body which appears of a perfectlyhomogeneous and gelatinous consistence in its natural state, is found, on more 126 HUNTER ON THE BLOOD. Four ounces of blood were taken from the arm, which, after coagulation, had the inflammatory crust upon its surface, and was also

minute inquiry, to be composed of upwards of five millions of fibres, which curiously interlock one another by an elaborate mechanism. 1 do not see, however, how this removes the difficulty; for as the albumen is unquestionably secreted, in the first place, into the oviduct as a fluid, it must on this supposition organize itself; which is all that is pretended to be said, ro argue as some have done, that because life proceeds only from life, by an uninterrupted succession from the creation, therefore life is the result of organization, appears to me an instance of false logic, unless it can previously be proved either that the albumen is not alive, or that, being alive, it is secreted already organized into the oviduct; neither of which propositions appears to me tenable. 1 shall now briefly advert to the opinions of other physiologists, especially of those who have rejected the idea of a vital principle. These have been compelled to give some definftion of life, and the following are examples. " L ensemble des fonctions qui resistent a la mort." (Bichat.) " Une collection des phenomenes qui se succedent, pendant un temps limite." (Richerand.) " Life is the assemblage of all the functions, and the general result of their exercise," or, in other words, " the result of the mutual actions and reactions of all parts." (Lawtuted by the conjoined operation of many actions." (Bostock.) " Life is simply an effect, the efficient cause of which is beyond the limits of human investigation. It is not a principle or source of action." (Grainger.) " L'idee de la vie est line de ces idees generales et obscures produites en nous par certaines suites de phenomenes, que nous voyohs se succeder dans un ordre constant, etse tenir par des rapports mutuels. Quoique nous ignorions la nature du lien qui les unit, nous sentons que ce lien doit exister, et cela nous suffit pour nous les faire designer par un nom que bientot le vulgaire regarde comme le signe d'un principe particulier, quoiqu'en effet ce nom ne puisse jamais indiquer que l'ensemble des phenomenes qui ont donne lien a sa formation......Ce mouvement general et commun de toutesles parties est tellementceque fait l'essencedela vie." (Cuvier.) Now the objection to all these definitions is, that they deal merely with the effects arising from the presence of life, or of the vital principle, and do not touch the question at issue, viz., of the nature of the principle itself. Let us apply these sort of definitions to some analogous subject, of inquiry, and we shall more readily understand this. Suppose, for instance, that a person wanted to ascertain the cause of motion in any complicated piece of machinery, as a watch or a steam-engine, and he were to be informed that " it was the combination of motions which resisted rest," or that it was a "collection of phenomena which succeeded one another for a limited time," or "that it was the result of the united actions and reactions of all the parts," &c, he would at once perceive that his informant either did not understand his question, or could not answer it. If by the term life we are to understand the complex assemblage of phenomena exhibited in a perfect animal, let it be so; in the same way as by the term movement we may understand the complicated actions and reactions in a piece of machinery: but let us not mistake such a definition for expositions of the original cause of the phenomena of life, or of the motions of machinery. Such a cause does exist, however, in the one case as in the other, and that quite independently of the particular form or structure of the animal or the machine, and perhaps independently of form or structure of any kind. Such definitions of life, therefore, as the preceding are plainly liable to the objection of making life dependent on organization and action, which appears to me to be nothing less than a complete reversal of the actual relations of cause and effect: for in regard to the cause, we cannot say that there is invariable antecedence or connexion; while in regard to the effect, it is not found invariably to follow the existence ofthe cause. We recognise the presence of life antecedently to all visible organization and action; and we also recognise its presence posteriorly to all action, as when GENERAL PRINCIPLES OF THE BLOOD. 127 cupped. On the same day, four ounces of blood were taken from another person's arm, which, on coagulating, showed no inflammaan animal is frozen or asphyxiated. On the other hand, life is sometimes suddenly and completely extinguished, without any apparent change having taken place in the organization of the body. On the Life of the Blood.—The difficulty of conceiving that the blood is endowed with life "arises merely," as Mr. Hunter observes, "from its being a fluid ;" but we have not the smallest reason for assuming a priori that in the nature of things there is a more intimate connexion between life and a solid than between life and a fluid. Let us, therefore, dismiss this prejudice entirely from our minds, and examine the real grounds on which the doctrine of the life of the blood rests. " From many circumstances attending this fluid, it would seem to be the most simple body we know of endowed with the principle of life;" consequently we should expect that the proofs of its vitality would be deducible chiefly from the resistance which it offers to external agencies. 1st. If a dead frog or eel be exposed to a freezing mixture, it sinks to 32°, freezes, and continues to fall to the temperature of the mixture. If the animal be alive it will sink to a few degrees below 32°, and remain at that point for a certain time, until the power of resistance be exhausted : it then dies, congeals, and sinks to the temperature of the mixture. If two eggs be similarly treated, one of which has had its powers of resistance destroyed by previous freezing, and the other is fresh, a like result is obtained : the former sinks uninterruptedly to the temperature of the mixture, the latter resists for a time at a few degrees below 32°, then congeals, and becomes cold as the former. If two portions of blood, one of which has been previously frozen and the other not, be exposed in a similar way to a freezing mixture, precisely the same thing occurs. Now are we not justified in concluding that the resistance to cold arises in each instance from the same cause ] If it is the possession of life which enables the eel and frog to maintain their temperature for a time, it is the possession of life which also enables the fresh egg and the fresh blood in like manner to maintain their temperature. The objection that the resistance in the blood may be merely from a remainder of vital influence imparted to it by the solids, rests on the notion that there is in the nature of things a greater connexion between asolid and life than between a fluid and life: but this is a mere assumption, the contrary of which may be the fact; for in a perfect animal, as the eel or frog, it is not until the fluids viz., the blood, &c, have become frozen that the animal is congealed. A solid deprived of blood is as little able to bear cold as blood separated from the solids. 2d. Parts of animals, such, for example, as the ears of rabbits, and even, whole animals, such as several insects in their chrysalis state, admit of being completely frozen without the necessary extinction of life. The blood in the same manner, admits of being frozen without destroying its coagulating property. As, however, the ears of a rabbit become flaccid, so the coagulum of blood which forms after it has been frozen is exceedingly loose. Cold acts as a sedative to the whole system, and if its action is sufficiently prolonged extinguishes life; but its action on the coagulation of the blood is precisely analogous, retarding or altogether preventing this act, in proportion to its intensity and continuance. 3d. In all vegetables and animals, particularly those which are high in the zoological scale, there is a disposition to maintain a uniform temperature. Thus "blood taken from the arm in the most intense cold that the human body can bear, raises the thermometer to the same [or nearly the same] height as blood taken in the most sultry heat." Thus also fresh blood is slower in parting with its heat than other fluids of a similar consistency and specific gravity, even before coagulation. 4th. The analogy of heat is not so well marked as that of cold, yet the blood resists any considerable increase of temperature, which is seldom found to exceed by more than 3° or 4° that of the standard. Again, " Heat has the power of exciting action in an animal; and we find that heat even increases the action 128 HUNTER ON THE BLOOD. tory crust on its surface. Both these quantities of blood were kept, in order to see which would resist putrefaction longest. By the

mscles of cold-blooded animals are rendered be injected into the vessels ; but as the effects of heat on the blood are precisely similar, it is reasonable to presume that they are analogous phenomena, and depend on the same cause. , 5th. Notwithstanding that the blood is constantly in a temperature the most favourable possible to putrefaction, yet, like the egg in the process of incubation, it resists every approach to this state ; and even out of the body it undergoes no decomposition for several days, but, like the muscles of the body, continues still further to contract. In proportion as the body is strong, so is the period during which the blood continues to contract and remain sweet prolonged ; but in diseases characterized with great debility, it speedily runs into the putrefactive state. Thus blood from old and infirm persons uniformly began to putrefy two or three days sooner than that from young and strong persons. Blood which had been violently agitated putrefied three days sooner than blood from the same person allowed to remain in perfect repose ; which maybe compared to the effect of hard running on the solids. So also blood which was first frozen at a temperature of zero, and then heated to 126°, putrefied three days sooner than another portion which was not meddled with. But as muscles exhibit exactly the same phenomena under the same circumstances, it is reasonable to suppose that they both depend on the same cause. 6th. Sir Charles Scudamore found that when animals were killed by the discharge of an electric battery, the temperature of the whole body was exalted precisely in the same manner as has been observed in regard to the blood. Caldwell also found that the blood, subjected to very powerful shocks of electricity, was five times longer in coagulating than blood allowed to coagulate in the natural way ; and after all it only coagulated imperfectly : effects which exactly correspond with those produced by electrical shocks on the muscular tissue. 7th. The effects of stimulants and sedatives on the blood and muscular fibre exhibit another train of analogies. Thus heat, electricity, exposure to air, motion, and very small proportions of salt and other extraneous substances all hasten coagulation, and excite muscular contraction. "The blood," Mr. Hunter says, " coagulates from exposure as certainly as the cavity of the thorax or abdomen inflames from the same cause." Many observers have professed to have remarked a manifest contraction of the clot on the application of salt (Stevens, p. 132) or galvanism (ReiPs Archiv. fur. die Phys., x. 417; and Biologie, iv. 654); but whatever effect is produced by the latter agent is probably due to the coagulation of the albuminous part of the serum interspersed in the meshes of the clot; the solidification of which may easily be supposed to occasion a sudden contraction of the whole mass. Tourdes, in his translation of Spallanzani, saw, or supposed he saw, a mass of blood agitated by an undulatory motion, analogous to the feeble oscillatory movements of a muscle; while Rosa has affirmed that the blood possesses an expansile and contractile property, by which it experiences alternate movements of dilatation and contraction, corresponding to the rhythm of the pulse, wherever it is removed from the living vessels of the body (Lettere Philos.). These observations, however, have not been confirmed. Mr. Hunter says that the more the blood is alive, the more readily it obeys stimulants, in consequence of which it coagulates more rapidly in health than in inflammation, and in the arteries than in the veins; but there are numerous facts of a contrary nature. (See notes, pp. 46, 49). 8th. On the other hand, the opposite effects of sedatives have been adduced to prove the same point. Thus, it has been argued, that as opium, belladonna, and other narcotic extracts retard or prevent coagulation, or diminish the subsequent GENERAL PRINCIPLES OF THE BLOOD. 129 fourth day, that without buff was putrefied ; but the blood with the inflammatory crust did not putrefy till the seventh day. In these

contractility of the clot, in the same manner and degree as these substances are known to affect the contractility of muscles, so it is probable that they both depend on the same cause. But the value of this argument is entirely destroyed, in my opinion, by the fact that the extracts of cinchona, gentian, and sarsaparilla, and many other substances of an equally inert kind, affect the coagulation of the blood much more strongly than the narcotic extracts, while many of the most powerful sedatives, as the hydrocyanic acid, have no appreciable effect on this process. The premiss, in short, is incorrect which assumes that any such actual relation exists between the effects produced by different agents on the blood and muscular fibre as to justify one in concluding from one to the other in any case. The most obvious and characteristic example of this sort is probably that of common salt, which equally and powerfully prevents the contraction of the crassamentum, the coagulation of the blood, and the contraction of muscular fibre; but as this agent has a similar effect in preventing the contraction of the coagulum of milk, even after trie acescent fermentation has commenced, it must be evident that such an effect can only proceed from a chemical operation. It is impossible, as it appears to me, to account physiologically for the fact that the extracts of belladonna and opium have less effect in preventing the coagulation of the blood than the extracts of sarsaparilla and gentian, and the infusions of tobacco and hydrocyanic acid than the infusions of tea or coffee. 9th. The coagulation of the blood has been already several times referred to, so that it will here only be necessary to advert to it again as aspecific point of analogy. However we may account for this phenomenon, it is impossible to overlook the strict parallelism which exists between it and the tonicity of muscles. In nineteen cases out of twenty, or ninety-nine out of the hundred, the same physiological causes which accelerate, retard, or entirely destroy the coagulability of the blood, increase, diminish, or entirely destroy the irritability of muscles. Coagulation has been compared to the last act of life, corresponding to the convulsion of. the muscles which takes place at the moment of death, and also to union by the first intention. " Coagulation," Mr. Hunter says, " I conceive to be an operation of life; and I imagine it to proceed on exactly the same principle as the union by the first intention;" that is, particle unites to particle, because they are endued with the same living principle, and consequently have a sympathetic affection upon simple contact, so as to affect each other. The circumstances connected with coagulation formed the chief of Mr. Hunter's arguments for the vitality of the blood, and have also been considered by Magendie as affording " une preuve demonstrative que le sang est doue de la vie." In a previous note, however, (p. 47,) I have offered a different explanation of this process, and therefore think it right to mention here that I consider the present argument as a real objection to that explanation, although not a sufficient one to overturn it. The subsequent and uninterrupted contraction of the clot for several days after coagulation, exactly corresponds with the gradual stiffening of the muscles after death, and therefore the presumption is that both depend on a physiological cause. I apprehend, however, that the same chemical affinity which first produced coagulation may still continue to act and to increase the effect; for acescency and even putrefaction in the coagulum of milk do not prevent a still further contraction of the clot, although it cannot be pretended that the coagulation of milk is a vital process, (since freezing and boiling have no effect in preventing it,) and still less that the contraction which subsequently occurs is due to such a cause. The analogy between the coagulum of blood and the coagulum of milk is at least fully as much to the point as the analogy between the contraction of muscles and the contraction of the coagulum of blood; so that the argument from this subject, in respect of the theories before mentioned, is ambidexter, and will receive its quality from other circumstances. 10th. Another argument is derived from the fluidity of the blood, which mani- 12 130 HUNTER ON THE BLOOD. two experiments it would appear that the inflammatory blood preserved its sweetness longest; but, from a repetition of these expenfestly depends on its vitality, whether this quality be conceived to proceed merely as an emanation from the surrounding living solids, or to be inherent m the blood itself (see note, p. 36). The former opinion is certainly favoured by what is mentioned in the next paragraph respecting the effect of poisons on thei blood; but the latter appears to me the most probable; first, because it makes the body one consistent whole; and secondly, because it assigns a sufficient reason why the blood does not instantlv solidify when it is extravasated from the body, and when, therefore, it must necessarily be placed beyond the reach of that influence which previously kept it fluid. A certain time is required before the blood concretes, and this time is generally found to bear a direct relation to the extent of contact which it has with foreign substances, v>hich appear to conduct away the living principle somewhat in the same manner as heat, electricity, and some other imponderable substances are conducted away under the same circumstances, r U Ll J 11th. The celerity with which impressions made on one part ot the blood are propacrated by sympathy throughout the mass. Fontana found that almost infi. nitesimal quantities of certain poisons instantly rendered the whole mass of the blood incoagulable ; while, on the other hand, other substances having a styptic quality had a contrary effect. (Op. cit., ii. 135.) Now as the poisons abovementioned had no influence whatever on the blood when extravasated from the body, it necessarily follows that the effect which they produced on the blood, while in the body, was physiological, and not chemical, either directly on the blood itself, or, as is most probable, intermediately through the containing vessels; a reciprocative sympathy, that is, must have existed, to have allowed of this action and reaction on each other, although it is impossible to conceive of any sympathy in a dead part. This harmony between the containing and the contained parts is preserved under all circumstances, and can only be ascribed to the sympathy which exists between vital parts. If the body is strong, the contraction of the clot is strong, and the period at which it begins to putrefy protracted ; but the reverse of these circumstances universally obtains in proportion as the powers of the whole system are debilitated. But the blood is not only believed to sympathize with the bodv, but with itself: that is, blood sympathizes with blood in the same manner as the solid parts of the body sympathize with one another. 12th. As I have already adverted (note, p. 68) to the volvular or rotary motion of the globules of the blood, I shall here only add further, that were this property clearly proved to belong exclusively to the products of organization, it would constitute in itself a sufficient and convincing proof of the vitality of the blood. The researches of Schultz, Dollinger, and more recently those of Dr. Alison (Supplement to Physiology, p. 18), are full on this point, and seem at least to render it extremely probable that the globules of the blood are endowed with vital attractions and repulsions, distinct from any motion impressed on them by the living solids ; that, in fact, the blood possesses all the properties of self-motion enjoyed by the solids. To the same head may be referred the' adherence of the coloured external tunics of the globules to their central nuclei, which is uniformly found to be strong in proportion as the strength and health of the animal is perfect. The repulsion also which exists among the globules themselves, by which their individuality is preserved, and their diffusion through the whole mass effected, can only be explained on the same principle. 13th. The blood is the first part which is formed in the embryo, being, in tact, the primordial rudiment to which the principle of life is attached, and from which, by successive elaborations, the various solids of the body are formed. This is one of Harvey's chief arguments, who denominates it the " particula genitalis prima," the " pars primigenia corporis," the " primum vivens et ultimo moriens" of animals. 14th. Allied to the last argument is that of Hunter: " The blood preserves life in the different parts of the body. When the nerves going to a part are tied or GENERAL PRINCIPLES OF THE BLOOD. 131

ments, it did not appear upon the whole that there was much difference.

cut, the part becomes paralytic, and loses all power of action ; but it does not mortify. If the artery be cut, the part dies, and mortification ensues......No part of the body is to be considered as a complete Jiving substance, producing and continuing life, without the blood.....It is not clear to me whether the blood dies sooner without the body, or the body without the blood.....Every part is formed from the blood, ami if it has not life previously to this operation, it must acquire it in the act of forming." Thus, the vascularity of a part is the measure of its vitality, and the extraordinary exercise of any function necessitates an extraordinary supply of blood. But it may be argued that the blood is no otherwise necessary to life than food is necessary : both are essential; but both may equally be regarded as simple aliments, on which the organization of the body operates so as to convert them into living structures. In continuation of the same argument, Mr. Hunter further says, " The blood has motion in a circle, in which circle it is in one view supersaturated, as it were, with living powers, and in another is deficient, having parted with them while it visited the different parts of the body." Dr. Davy consequently asks, whether we are to regard the circulation as " a perpetual miracle, in which material particles are, without cessation, dying and reviving?" But how does Dr. Davy know that the venous blood is dead ? It is plain also that the same question might with equal force be asked respecting the whole body, which cannot subsist without a continual supply of fresh blood ; the solids require fresh blood as much as the blood requires fresh air, in order to continue life, so that a something is acquired in both cases, and that something is essential to life, or at least to its continuance. 15th. "If the blood had not the living principle, it would be in respect of the body as an extraneous substance ;" wounds would not unite as they do, by the first intention, because the coagulated blood would have first to be thrown off as a foreign body, by suppuration, and all echymoses would form abscesses : but the contrary of all this happens, for we see the blood everywhere adhere to freshcut surfaces without irritating them, on exactly the same principle that cut surfaces themselves adhere to one another. The case of certain fluids, such as bile, urine, &c, not irritating their respective receptacles, is no argument against this view of the subject; since there is not one of the secretions of the animal body which would not irritate a cut surface, and prevent union by the first intention. The scorpion can destroy itself by its own poison, although that substance is perfectly innocuous in its proper vessels. 16th. " A body may be so compounded as to make a perfect whole of itself, having no parts dissimilar, and having the same properties in a small quantity as in a great." If, then, the blood be of this kind, motion or division cannot affect it, for all the parts are similar, and independent of the rest. "The blood has as much the materia vitse as the solids, which keeps up that harmony between them." The value of this argument may be estimated by referring to note \, p. 116. 17th. Blood, when it coagulates, has an unquestionable disposition to assume a peculiar arrangement, corresponding to the organization of the most simple membranes ; the globules of the blood, that is, arrange themselves into piles or rouleux, so as to constitute fibrils, which variously intersect one another, unlike any other thing in nature, except the chyle, which Hunter supposed to be endowed with life equally with the blood. Sir E. Home imagined that the blood, on coagulating, formed a sort of tubular structure, in consequence of the escape of carbonic acid gas; but this notion has been completely exploded by more correct observation. The incipient organization of the clot seems entirely to depend on the polarizing forces of the ultimate globules. I apprehend, also, that it would be difficult to deny that the globules themselves may possess an incipient organization, inasmuch as they evidently consist of separate parts, have a determinate shape, and are larger than the ova of many animalcules, or even than the animal 132 HUNTER ON THE BLOOD. To see whether the blood in a young person or an old one become soonest putrid, I desired that the following trials should be made : June 24th. Some blood was taken from a woman twenty years of age, and its surface, after coagulation, was covered with an inflammatory crust. On the same day some blood was taken from a woman aged sixty, the crassamentum of which was also covered with an inflammatory crust. These quantities of blood were set by. The blood from the old woman putrefied in two days. That from the young woman kept quite sweet till the fifth day, when it began to smell disagreeably; in this state it continued two days more,and then omitted the common odour of putrid blood. Several experiments were made in the course of the summer, of a similar nature with the last, in all which it appeared that the blood from young people kept longer sweet than that which was taken from the old. In October, 1790, when the weather was cold, some blood was taken from two men, one of whom was seventy-five years of age,

cules themselves, of whose organization there can be no doubt. Some have regarded these particles as distinct monads, possessing an independent vitality. 18ih. The last argument for the coagulation of the blood is derived from the phenomenon of union by the first intention, and the power which the blood has of originating and carrying on organization and action within itself. " Animate and vegetables have a power of action within themselves," by which they are capable "of working themselves into a form and a higher state of existence. Now the blood seems to possess this characteristic properly of life as well as the solids, for extravasated blood " forms either vessels in itself, or vessels shoot out from the original surface of contact into it. ... I have reason to believe that the coagulum has the power, under necessary circumstances, to form vessels in and of itself. .... I think 1 have been able to inject what I suspected to be the beginning of a vascular formation in a coagulum, when it could not derive any vessels from the surrounding parts." But it may be asked how could these vessels be injected if there was no connexion 1 The decision of ihis point would afford a true "crucial instance" decisive of the vitality of the blood ; but unfortunately the present state of science does not enable us to come to any satisfactory conclusion in this matter. I have already intimated (note, p. 49), that Hunter's notions on the subject of union by the first intention do not seem supported by sufficient data ; but I must beg leave to refer the reader to part ii. chap. i. for the evidence which at present exists on this subject. There can be little doubt, I think, that effused lymph has a power of self-organization ; but I apprehend it is taking too much for granted to suppose that lymph effused from a cut or inflamed surface is identically the same as lymph as it exists in the circulating blood. I shall only further observe, that the argument for the vitality of the blood is strictly a cumulative one, and must be viewed in its totality in order to estimate its real force. Taken altogether, the preceding facts raise at least a strong presumption in its favour, not to say a high probability. It may seem inconsistent, after having rejected two of the most material arguments (viz., those founded on coagulation and union, by the first intention), that I should introduce them into the present argument; but it should be remembered that these are the arguments employed by Hunter. The explanation of these facts by Mr. Hunter is not demonstrated to be false, but oniy another explanation is offered, which appears to me to account more easily for the phenomena in question. It is a balance of probabilities, and therefore I conceive it perfectly legitimate to introduce the minor probability into the question, which will carry weight in proportion as it is corroborated by other circumstances.] GENERAL PRINCIPLES OF THE BLOOD. 133 and the other eighty-three, about six ounces from each. The blood from each kept sweet till the fifth day; but on the sixth both quantities smelt equally putrid, which uniformly accords with the preceding experiment. To see if recent blood or coagulated blood lost its heat soonest, four ounces of blood, after coagulation, were heated till the mercury of a thermometer, placed in the middle of the coagulum, was raised to the 98th degree. The thermometer was then put into a similar quantity of blood, immediately after it was taken from the vein, in which the mercury stood at 90°. These were placed by each other, and the thermometer put alternately into each, to observe how they parted with their heat. At the beginning of the experiment After two minutes...... After four minutes more .... After two minutes more .... After two minutes more ....

This experiment was not accurately made, for the two bloods should have been of the same temperature, because the warmer any body is, the faster it will lose its heat to any neighbouring colder body; yet 1 believe that the coagulated blood lost its heat faster than the fluid blood. To see whether a stimulus can be applied to the blood, so as to make it coagulate faster than it does naturally, I desired the following experiment to be made : Three ounces of blood were taken from a boy about ten years of age, and immediately after the cup was put into water heated to 150°. A similar quantity was taken in another cup from the same boy, at the same time, which was put into water heated only to 18°. The first coagulated completely in five minutes, but the latter remained quite fluid for twenty minutes, and then began to coagulate, but was not completely coagulated for five minutes more. When looking at each portion of blood an hour afterwards, it appeared that the blood which coagulated in the warmest manner had the greatest proportion of serum, and the least of crassamentum ; but by next morning the serum in each was equal in quantity, and the crassamentum of equal size. This experiment shows that heat above the natural standard acts as stimulus upon the blood, and makes it coagulate considerably sooner than cold does, though not more firmly. This heat did not act as heat upon the blood, but only as the stimulus; for heat acting as heat would also have coagulated the serum, which was not the case. This experiment, or a similar one, is brought forwards as one of the proofs of the living principle of the blood, where it is. oontrasted with a similar experiment on living muscles. To see wrhether blood, when mixed with different substances in 12* Coagulated Recent Blood. Blood. . 98° 90° . 97 89 .93 88 . 92 87 . 91 86 134 HUNTER ON THE BLOOD. strong solution, and which appeared to prevent coagulation, would, when diluted with water, admit of coagulation : In December half an ounce of blood, immediately after it was taken from the arm, was mixed with one pound of water. Ihis was intended as a standard to judge of the others. More blood was taken from the same person at the same time, to which a strong solution of Glauber's salts [sodas sulphas] was added ; this altered its colour to a florid red, and was found to prevent it from coagulating. A strong solution of Glauber's salts, therefore, has the power of preventing the coagulation of the blood. Ten minutes after this mixture half an ounce of it was mixed with one pound of water ; half an hour after, another half ounce was mixed with one pound of water ; at the end of an hour the same was done, and also after two hours : all these'were allowed to stand twenty-four hours, when the pure blood and water had deposited a considerable darkcoloured sediment, and a light-coloured blood was suspended, whieh had begun to subside, leaving the fluid above perfectly transparent, and of a beautiful red colour. The different portions of blood which had been first mixed with the salt, and afterwards with water, had the cloud exactly like that of the pure blood, but there was no sediment whatever at the bottom of the vessel: this cloud gradually subsided, and left the fluid above of a beautiful red colour, and also quite transparent. At this time (viz., twenty-four hours after the mixture of the salt with the blood), another half ounce was mixed with one pound of water, and next day the appearances were exactly similar to what have been already described. The sediment in the pure blood was most probably the coagulating lymph; and as there was none in the others, it is most likely that the lymph in them did not now coagulate. As medicines, when taken into the circulation, whether by the stomach or by the skin, produce considerable effects on the constitution, I wished to know what effect such substances would have upon the blood with regard to the act and power of its coagulation. Two ounces of blood were received from the arm into a vessel, as a standard of natural coagulation. Two ounces more were taken in another vessel, to which one ounce of water was added. The intention of this addition was to put this blood in the same circumstances with blood in other comparative trials respecting water, so that the difference, if there was any, must belong to the substance mixed with the blood, independent of the water. Two ounces more blood were received in another vessel, to which was added one ounce of the decoction of bark. These different quantities were taken from One person, one after the other, in the same order in which they are here set down. After six minutes, the blood mixed with water was quite coagulated ; after nine minutes, that mixed with the decoction of Peruvian bark formed a loose coagulum; after twelve minutes, the blood first drawn coagulated; the coagula of the first and second drawn blood GENERAL PRINCIPLES OF THE BLOOD. 135 were equally firm, the water, in the second having been squeezed out along with the serum ; but that mixed with the decoction of bark was much less so. It appears from these experiments that water rather hastened coagulation, but made it neither firmer nor looser in the texture. In the following experiments the blood was first all received into one vessel, and stirred before it was mixed with the different substances. The intention of this was, that the three portions of blood might all be exactly under the same circumstances. Two ounces were poured into a vessel as a standard of natural coagulation. Two ounces more of blood were poured into another vessel, to which were added two ounces of water, as in the former experiment. Two ounces more were mixed with two ounces of the decoction of bark. After twelve minutes, the two first were coagulated, and the coagula were equally firm; after fourteen minutes, that with the decoction of bark coagulated, but the coagulum was very loose. Upon comparing the three coagula next day, that which had the decoction of bark mixed with it was by much the least firm. This experiment was repeated, and the result was nearly the same; and it shows that even putting equal parts of water and blood together did not alter the time or the firmness of coagulation, but that the decoction of bark evidently did.* Some blood was taken from the arm into a basin, stirred, and then mixed with different infusions, as follows: Two ounces were mixed with the same quantity of the infusion of columba root; two ounces with the same quantity of the infusion of gentian ; two more with two ounces of the watery solution of opium; and two ounces were kept in a vessel by themselves. The blood which had been mixed with the bitter infusions, and the simple blood, all coagulated at the same time, viz., in six minutes ; but that which had been mixed with the infusion of gentian was firmer than with the infusion of columba root, but was not more firm than the coagulum of the simple blood. The blood which had been mixed with the solution of opium did not coagulate for twelve minutes, and then the coagulum was very loose. This experiment with the opium was repeated, and the result was exactly the same.

* [Scudamore obtained a different result. In two experiments in which three or four parts of water at 80° were mixed with fresh-drawn blood, coagulation was retarded till nine and fourteen minutes, acquiring then only the consistence of a tremulous jelly ; whereas similar portions of the same blood, to which no water was added, coagulated firmly in five! (Op. cit., p. 38.) The effect of water, however, on coagulation depends on the quantity employed : equal parts, and all proportions under that, were uniformly found to hasten coagulation, although thirty or forty parts of water retarded the deposition of the fibrin at least a full hour. (Prater, pp. 17. 80.) When considerable quantities of water are employed, it is probable that coagulation is delayed by the coagulating particlea being removed to a greater distance from each other.] 136 HUNTER ON THE BLOOD. Of extraneous matter in the Blood.—Whatever is dissolved in the blood must be only diffused through it, not chemically combined with it, otherwise the nature of the blood itself would be altered, and the effect of medicine destroyed. The blood can receive and retain extraneous matter, capable of destroying the solids, by stimulating to action so as to destroy them.* Extraneous matter in the blood is capable of altering the chemical properties of the solids in those who work in lead, as is evident in the following case. Morgan, a house-painter, who had been paralytic in his hands and legs for a considerable time, was thrown down, and had his thigh-bone broken just below the little trochanter. The upper end of the inferior portion had passed over the outside of the other, and moved with the knee, so that the end of the lower bone was taken for the great trochanter ; but I discovered the fracture by extending the leg, and got the portions of bone in their places, and bound up the limb with a roller. It went on well for nearly a fortnight, only his hands swelling at times, which gave way to fomentations: in the third week he grew very ill, became low, had a kind of lethargy, a great deal of blood came out of his mouth, he sunk still lower, and died about three weeks after the accident. On examining the body after death, the muscles, particularly those of the arms, had lost their natural colour; but instead of being ligamentous and semitransparent, as happens in common paralysis, they were opake, resembling exactly in appearance parts steeped in a solution of Goulard's extract. From this case it appears the lead had been evidently carried along with the blood, even into the muscles themselves. [Dr. Christison has shown not only that particular poisons physiologically affect particular structures, or, in the language of Hunter, "take their different seats in the body as if th^y were allotted to them," but that they have also a disposition to accumulate substantially in particular organs. {On Poisons, p. 15, ct passim.) It is doubtful, 1 think, whether Hunter was correct in supposing that the lead actually combines with the muscular fibre in the living body. In the dead body this certainly happens; that is, the oxide of the metal enters into direct combination with tke animal fibre; but it is scarcely conceivable that this can happen in the living body. (Traits. Col. of Phys., i. 317.) With respect to the effect of various reagents on the blood, I have but little to sny. Dr. Davy (Edin. Med. and Surg. Jour., xx. 257), Dr. Scudamore, Mr. Prater, and a number of other writers on the blood, have dwelt largely on this branch of the subject; but, as far as I understand the experiments which have been made, they do not seem to me to warrant any general conclusions respecting the physiology of this fluid. The extreme proneness of all organic bodies to undergo changes of constitution, and to assume new states of existence, in consequence of slight * See Principles of Surgery, p. 139, note. GENERAL PRINCIPLES OF THE BLOOD. 137 external causes, is an objection in limine to all such inquiries; but, in addition to these circumstances, the blood possesses a principle of life, so that it is neither possible to separate the physiological from the chemical effects, nor to arrange these effects upon any general principle derived from the nature of the agents employed. The most inert substances produce effects of the most marked kind, while bodies of the most destructive and virulent nature are almost totally inoperative. Some bodies, as the concentrated mineral acids, act from a purely chemical effect, decomposing and consolidating the blood, and entirely destroying its colour and contractility; others, as many of the metallic oxides, induce coagulation, partly from a physiological, and partly from a chemical, effect,—precipitating and combining with the albumen. The caustic alkalis dissolve the fibrin, and keep the blood permanently fluid ; most of the neutral salts and vegetable extracts also retard, or entirely prevent, coagulation ; although this effect is not permanent, for coagulation may subsequently be induced, by dilution with water, in the great majority of instances. The extracts of sarsaparilla, bark, and gentian, reuder the blood permanently fluid, although little or no effect is produced by arsenic, tobacco, extract of belladonna, or hydrocyanic acid. A longcontinued temperature of 32°, a heat varying from 140° to 150°, the citric and tartaric acids, and a great variety of physiological causes, all produce the same effect, viz., that of gelatinizing the blood. Now it is impossible, in the present state of science, to refer these incongruous effects to any general principle, because we are entirely ignorant of the mode by which the generality of these agents operate. It is possible that bulky powders and extracts may prevent coagulation, in consequence of the interposition of their particles between the coagulating particles of fibrin; but then these are only a few instances out of a great number ; besides that, on this supposition, the retarding effect ought always to be in proportion to the bulk of the substance employed, which is far from being the case. Dilution with water, as I have before observed, seems. to operate in this way. The explanation of the incoagulability of the blood, when the neutral salts are added, upon the principle of the expansion or contraction of the globular particles, appears to me totally inadequate to explain the phenomenon, even though we should admit the fact that the globules of the blood do actually contract and expand in the manner supposed; for if the opinion formerly given (note, p. 28), be correct, that the fibrin of the blood is quite independent of the red globules, it will be a matter of perfect indifference of course in what manner the globules may be affected, ft is remarkable that blood kept fluid by means of salt retains its florid colour for years, and also its property of coagulating when diluted with water. Dr. Davy has made the curious remark, that when coagulation is prevented by a foreign admixture, the blood does not putrefy, although this effect is produced as usual by dilution with water. It is also deserving of remark, that most substances which, when added in quantity, retard or prevent coagulation, accelerate this process when added only in small proportions; thus, electricity, hard running, and even the neutral salts, which are so powerful for keeping the blood fluid, manifestly hasten its concretion, if not carried to excess, agreeably to a general physiological law, that stimuli universally become sedative when carried to their utmost point. 138 HUNTER ON THE BLOOD. BIBLIOGRAPHY OF THE BLOOD.

Ackermann, J. F. Comment, de Combustionis lenta; Phaenomenis, qu«, Vitam organicum constituunt. 1805.---Adams, J., M.D. An Illustration of Mr. Hunter's Doctrine of the Blood. 1814.----Addon, N. P. Physiologic 2eme edit. 1829. hi. 110.----Albinus, B. Dissert.de Massae Sang. Corpusculis, 1688; et Dissert, de Pravltate Sang. 1G89. ----*Alison, M. P., M.D. Physiology, 2d edit. 1833. p. 62; and Supplement. 1836.----Amid, Professor. Edin. Med. and Surg. Jour., xv. 120. On the Shape of the Globules.----*Andral, G. Precis d'Anat. Pathol. 1829. i. 11. tr. by Drs. Townsend and West; et Clin. Med. 2eme edit. 1829-35. iv. 683. et passim. Sur les Lesions de Circulation.----Anon. An Essay on the Transmutation of Blood. 1725. ----Autenreith, J. F. H. Dissert, de Sang. 1792.

* Babington, B. G., M.D., Med. and Chir. Tr. xvi. 46. (1830.) On a concrete Oil, &c, as a Principle of Healthy Blood; and ib. p. 292. Considerations with respect to the Blood.----Bader, J. H. L. Exper. circa Sang. 1788.----Baerts. Diss.de Nat. Sang. Inflamm. 1782.---- Barbatus, H. Tractatus de Sang. 1667.----Barruel, M. Ann. d'Hyg pub. i. 267. (1829.) Sur un Principe propre a characteriser le Sang de l'Homme et des Animaux.----Bartholinus, J. Misc. Acad. Nat. Cur. 1671. p. 23. Observ.de Sang, verminoso.----Bastays, M. de la. Sur les Mai. chron. qui proviennent de la Comp. du Sang. 1780.---- Bauer, F. Phil. Tr. 1818. p. 173. On the Form and Size of the Globules.----Beale, B. On vicious Blood as a Cause of Disease. 1706. ----Bell, J. Anat. and Phys., 4th edit. 1816. i. 503. On the Properties of the Blood, containing a refutation of Mr. Hunter's doctrine of the vitality of this fluid.----Bellengeri, C. F. J. Experimenta in Electricitatem Sang., &c. 1826; also in Annali Univ. di Med. 1827; and Lancet, xiii. 810.----Bennet, C, M.D. Exerc. Diagn. (Sang. vitiis.) 1654.----Berdoe, M., M.D. An Essay on the Nature, &c, of the Blood. 1772.----Berlhold, A. A. Beitriige zur Anat. Zool. und Phys. 1831. p. 259.----*Berzelius, J. J. Med. and Chir. Tr., iii. 198. (1812.) On the Chemical Properties of the Animal Fluids and particularly of the Blood ; also Traite de Chim., tr. par A. J. L. Jourdan et M. Esslinger. 1829-33. vii. 27. Le Sang.----*Bichat, X. Anat Gen. 1801. ii. 1. tr. by C. Coffyn, 1824; and additions, par P. A. Beclard. 1821. p. 72.—Rech. Phys. sur la Vie et la Mort, 3eme edit. 1805. p. 170, et passim, tr. by F. Gold.—Journ. de Sante de Bordeaux, ii. 61. ----Blainville, D. Phys. Gen. et Comp. 1829-30. i.----Blundell,J. M.D. Med. and Chir. Tr. ix. 56. (1818.) On the Transfusion of Blood-----Blumenbach, J. F. Medicin-Bibliothek. 1783. i. 177.— Comm. de Vi vitali Sang. 1788; etComm. Soc'. Gotting. ix. 3.—Inst. Phys. edit. 4ta, 1821. tr. and greatly augmented by J. Elliotson, M.D. 5th edit. pt. i. 1835. p. 143.----Boerhavii, H. Praxis Medica. 1728. Aph. 58-144. et Pra?l. Acad, a Haller. 1740. §123. et nota.----Bor-

• Those authors which appear to possess the best claim to the student's attention are indicated by an asterisk; many other names, however, of scarcely inferior excellence, are passed over, in consequence of the necessity of stopping somewhere. BIBLIOGRAPHY OF THE BLOOD. 139 deu, T. (Th.) De Analy. Med. du Sang. 1775----Bornholt. Dissert. de Sang. Pravitate. 1702.----Borelli, J. A. De Motu Animalium. 1680. ii. prop. 132. Anal. Sang, et Forma ejus Comp.----Borelli, P. Hist. et Observ. Med. Phy. Centuria. 1553. Cent. iii. obs. 4____*Bostock, J., M.D. Med.and Chir. Tr., i. 47. (1809.) On the Gelatin of the Blood. —Physiology, 2d edit. 1828. i. 428.—Edin. Med. and Surg. Journ., xxxi. 114. (1829.) Obs. on the Coag. of the Blood.----Boudet, F. Arch. Gen.de Med. 2deser. ii. 128.----Bouillaud, Professor. Journ. Hebd. de Prog, des Sc. Med. iii. 353. (1835.) Reflexions sur les Alter, des Liquides et sur l'etat du Sang dans les Inflam. putrides.----Bouillon la Grange, E. J. B. Manuel d'un Cours de Chim. 1812. ii. 469.---- Boulton, R. Of the Heat of the Blood, &c. 1698.----Boyle, Hon. R. Mem. for the Nat. Hist, of the Blood, &c. 1684.; and Phil. Tr. 1665. pp. 100, 117, 139.----Bowerbank, J. Entom. Journ., i. Micros. Observ. on the Blood of Insects.----*Brande, W. T., Phil. Tr. 1809. p. 373. Obs. on Albumen and some other Animal Fluids ;—ib. 1812. p. 90. Chem. Researches on the Blood, Sic;—ib. 1818. p. 181. On the existence of Carbonic Acid in the Blood.----Brandt. Encyc. Worterb., art. Blut. bde. v. (1830.)----Bretchneider, F. F. Comm. de Gener. Crustae Inflam. 1788.----Browne, J. Essay on the Fundamentals in Physic, and upon the structure of the Blood. 1709.----Brunea. Dissert, de Mala Sang. Temperie. 1707.----Bright, R., M.D. Rep. of Med. Cases. 1828. ii. 63, et passim.——*Burrows, G. M.D. Med. Gaz. xiv. 502. etseq. (1834), and xvi. 647, et seq. (1835.) Gulstonian and Croonian Lect. on the Blood and Urine.----Butt, J. M. (Th.) De Sang, spont. Separ. 1760.; reprinted in Sandiford's Thesaurus Dissert. 1768-78. ii. 501.----*Burdach, K. L. Die Physiologie. 1826-35. bde. iv. vom Blute.----Burthart, J. R. Ueber das Blut und das Albumen, &c. 1828.----Bushnan, J. B. Hist, of a case in which Animals were found in the Blood. 1833.

Caldani, L. M. A. Mem. di Padova, v. 1. Osserv. Micros, sulla Figura delle Molecole rosse del Sangue.----* Caldwell, C, M.D. On the Vitality of the Blood. 1805.----Carminati, B. Risult. di Sperienze ed Osserv. su il Sangue. 1783.----Carridori, M. Annali di Chimica, xiv. 86. (1797.) Exp. on the Coag. of Albumen.----Carvinus. De Sanguine, &c. 1562.----Carswell, R., M.D. Path. Anat. 1833-6. Art. Pus, et passim.----Cavallo, T. Essay on Factitious Airs, with an App. on the Nature of the Blood. 1798.----Chaillon, J. Rech. de l'Origine du Sang. 1675.----Chevallier, A. Ann. d'Hyg. pub. iv. 433. (1830.) Examen des Taches du Sang, &c. See Burrael.----Chevreul, M. Journ. de Phys. par Magendie, iv. 119. (1824.) Consid. sur la Nature du Sang; et Ann. du Museum, x. 445.----Chomel. Diet, de Med., art. Anemie. 1821.----Christison, R., M.D. On poisons. 2d edit. 1832. p. 586, et passim.—Edin. Med. and Surg. Journ., Oct. 1829. On Milky Serum:—ib. xxx. 94. (1831.) On the mutual Action of Blood and Atmosph. Air.----Clandcr, G. Misc. Acad. Nat. Cur. 1688. p. 326. Sanguis fere albus sine damno aliquot annos durans.----Clanny, W. R. M.D. Lectures on Typhus, and the Changes of the Blood in it. 1828. ----Coleman, E. On Respir. and the Changes the Blood undergoes. 2d edit. 1802.----Collard de Martigny. Journ. de Phys. par Magendie, viii. 152. (1828.) Recher. Exp. sur les Effets de 1'Abstinence sur la 140 HUNTER ON THE BLOOD. Comp. et sur la Quantite du Sang; et ib. x. 111. Rech. Exp. sur la Respir., &c.----Copland, J., M.D. Diet, of Med. 1835. art. Blood. ----Couerbe, M. Ann. d'Hyg. pub. iv. 479. (1830.) Reflexions sur le Principe Volatit du Sang.----Courten, W. Phil. Tr., xxvii. 485. Exp. and Obs. on several sorts of Poisons on Animals.----Cruveilhier, J. Anat. Path. 1828. passim.----Crawford, A., M.D. Exp. and Observ. on Animal Heat. 2d edit. 1788.----Carrie, J., M.D. Essay on the Vitality of the Blood. 1791.

Dance, M. Arch. Gen. de Med., xviii. pp. 289, 473 ; and xix. pp. 5,161. Changemens que subit le Sang dans le Fievre continue et dans la Phlebite.----Davies, R. Essays to promote the exp. analyses of the Human Blood. 1760.----Davy, Sir H. Researches on Nit. Oxide Gas. 1800.----*Davy,J.,M.D.(fh.) De Sang. 1815.—Phil. Ttans. 1822. p. 271. Observ. on the Buffy Coat of Blood.—Edin. Med. and Surg. Journ. xxix. 244. (1828.) On the Spec. Grav. of Blood and Serum:— ib. p. 254. On the Carb. Acid in the Blood:—ib. xxx. 248. (1829.) On the circumstances which affect Coagulation:—ib. xxxi. 21. (1829.) Is the Blood a living Fluid ?—ib. p. 287. On the Nature of the Blood:— ib. xxxiv. 243. (1830.) On the Action of Atmospheric Air on the Blood.----De Haen. Ratio Med., pars i. c. 6 et 25; et iii. c. 33-34. ----*Denis, P. S. Rech. Exp. sur le Sang. <fcc. 1830; et Journ. de Phys. par Magendie, ix. 176. (1829.)----De Sandris, J. De Nat. et Pranernat. Sang. Statu. 1696.----Deyeux, N. Mem sur les Alter, du Sang. 1797.—Journ. de Physique, xliv. 438. (1804.)—Consid. Chim. et Med. sur le Sang des Icteriques.----Diest,I. An sui Sanguinis solus Opifex Foetus ? 1735.----Dieffenbach, J. F. Die Transfusion des Blutes, &c. 1828.----Doemling, J. J. Giebt es urspriingliche Krankheiten der Safte ? 1800.----Dolimger,J. Was ist absonderung, und vvie geschieht sie? 1819; and Denkschriften der Koniglichen Acad. der Wissenschaften zu Munchen, vii. 184.----Done, Lecture faite a l'Acad. des Sc. 1834.----Doivles, T. Med. and Chir. Tr. xii. 86. (1823.) On the Products of acute Inflam.----Duplay, A. Arch. Gen. tie xMed. 2d ser. vi. 223. (1824.) Obs. d'une Alter, tres-grande du Sang. ----Dupuy, M. Arch. Gen. de Med., xiv. 289. (1827.) De 1'Effet de la Ligature et du Section des Neil's de la 8eme paire sur le Sang.---- Dumas, C. L. Physiologic 1800-3. iii. 377.—Recueil Period, de la Soc. de Med. de Paris, xxxiii. 353. Exp. a determiner l'influence des 8 Nerfs sur le Color, du Sang.—See Prevost.

Edwards, H. M., M.D. Repert. Gen. iii. part 1. p. 25. (1827.) Sur la Struct, intime des Tissus.----Eller, J. T. Mem.de Berlin. 1751. p.3. Nouvelles Exp. sur le Sang humain.----Ellis, D. An Inquiry into the Changes produced on Atmospheric Air. 1807.—Further Inquiries. 1811.----*Engelhart, J. F. Comm.de vera Materiae Sanguini purpureum Colorem impertientes natura. 1825.—Edin. Med. and Surg. Journ. xxvii. 94. (1827.)----Everts, B. H. Dissert. Phy.-Med. de Haematosi.

Falconer, M. Exper. Inquiries concerning the Blood. 1777.----Funtana, F. Nuove Osserv. sopra i Glob, rossi del Sangue. 1766.---- Fontana, G. Atti di Siena, vi. 161. De Sang. Restitutione.----For- BIBLIOGRAPHY OF THE BLOOD. 141 get, C. Journ. Hebd. de Prog, des Sc. Med. 1834, 1835. p. 353. De l'Humorisme rationale.----*Fourcroy, A. F. Syst. des Connoiss. de Chim. 1801. ix. 185. Sur le Sang.—Ann. de Chim. vi. 182. vii. 147: et Mem. de l'Acad. des Sc. 1789. p. 297. Sur les Alter, du Sang par l'lnfl. de I'Air.----Fracassinus, A. Osserv. del Sangue. 1766.

Gaber. De Humoribus Anim.—■—Galen. Opera. 1679. iii. De Elementis. ----Gatti, E. A. Saggio sul Sangue e sul Salasso. 1824.----Gaspard, G. Journ. de Phys. par Magendie, ii. 1. (1822.) iv. 1. (1824.) Mem. Phys. et Med. sur les Maladies Putrides, &c.----Gaubius. Instit. Pathol. 1763. § 339. et seq.----Gendrin, A. N. Hist. Anat. des Inflam. 1826 passim.----Gigna, J. F. Misc. Societ. Taurin. (1758.) i. 68. De Colore Sang.----Gordon, J., M.D. Ann. of Phil. iv. 139. (1814.) On the Extrication of Caloric during the Coagulation of the Blood.---- Grant, R. E., M.D. Lect. on Comp. Anat. in Lancet. (1833-4.) ii. 865 et seq.----Gruithuisen, F. P. Beitrage zur Physiognosie et Tautognosie. 1812. § 89.----Gruner, C. G. Dissert. Path. Sang. 1791.---- Guglielmini, D. Opera. 1701. ii.§44. De Sang. NaturaetConstilutione.

Hall, M., M.D. Med. and Chir. Tr. xiii. 121. (1827.) On the Effects of loss of Blood ; and also separately. 1830.—Encyc. of Med. 1832. art. Blooo.----Halhr, A. Elem. Phys. 1757-66. ii. lib. 5.—Deux Mem. sur le Sang, &c. 1756. tr. anon. 1757.----Hammerschmidt, J. A. Discrimen inter Sang. Arter et Ven. 1753.----Harlcs, J. C. F. Hist. Sang. 1794.----Hartman. Diss, super crustae Inflamm. origine.---- Harwood, Dr. Phil. Trans, abr. i. 185, note. Exp. on Transfusion. ----Harveii, G. Opera. 1766. De Gener. Exerc. 52.----Helwich, C. Misc. Acad. Nat. Cur. 1697-8. 446. De Copia Ferri Sanguinis, &c. ----Herbst, E.F. G. commentatio, &c. De Quantitate Sang. 1822. ----Hermann, Professor. Arch, de la Med. Homaeop. ii. 255 ; et Ann. d'Hyg. pub. vi. 342. (1831.) De l'Anal. du Sang des Choleriques. ----Henke, U. Ueber die Vitalitat des Blutes und Siifte Krankheiten. 1806.-----Hewson, W. An Exp. Inquiry into the Properties of the Blood. 1772-7; and Phil. Trans. 1770. pp. 384,398. On Coagulation: —ib. 1773. p. 303. On the Figure of the Red Globules.----Hey, W. Observ. on the Blood. 1779.----* Hodgkin, J. Phil. Mag. ii. 130; and Appendix to tr. of Edwards's work Sur l'lnfl. des Agens Phys. sur la Vie. On the Size and Form of the Globules of the Blood and animal Tissues----Hodgkin, J. On the Diseases of Arteries and Veins. 1815. p. 83 et passim.----Hoffmann, F. Med. Ration. Syst. lib. i. § 1. c. 5. ----Hoffman, M. Dissert, de Sang. 2660.----* Hoffman, G. H. Lond. Med. Gaz. xi. 881. (1833.) Exp. on the Colour of the Blood, and on the Gases which it contains.----Hoffman, J. M. Acta Acad. Nat. Cur. i. 466. De Sang, lacteo.----Home, Sir E. Phil. Trans. 1818. pp. 172, 185 ; and 1820. p. 1. On the changes the Blood undergoes in the act of Coagulation:—ib. 1826. p. 189. On the Coagulation of the Blood by Heat.

Jennings, E. A. Trans, of the Prov. Med. and Surg. Ass. iii. 43. A Report on the Chemistry of the Blood.----Junker, J. Chymia. p. 75 ; et Conspectus Path. 1736 passim.----Jurin, J. Phil. Trans. 1719. p. 1000. Exp. relating to the Spec. Grav. of the Blood. 13 142 HUNTER ON THE BLOOD. Kater, Capt. Phil. Trans. 1818. p. 187. On the Size of the Globules. ----Kaltenbrunner, G. Exp. circa statum Sang.iu Inflam. &c. 1826: see also Repert. Gen. iv. 201. (1827.); et Journ. de Phys. par Magendie, viii. 81. (1828.)----Kay, J. P., M.D. On Asphyxia.1834----Keill, J. M.D. Phil. Trans. 1706 and 1708. On the Quantity of the Blood in the Body.----Klein. Dissert, de Sang., &c. 1737.----Knight, T., M. D. A Vindication of the late Essay on the Transmutation of Blood. 1731.----*Kolck Schroder van der, J. Z. C. Diss, sistens Sang. Coag. Historiam cum Exp., &c. 1820.----Kbnig, G. Exper. circa Sang. Inflam. etSanit. 1824.----Krimer, IV. Versuch einer Phys. des Blutes. 1823.----Krouaner, J. H. Dissert, de Sang. Hum. 1762.

Lamure, F. Rech. sur la Couenne du Sang.----Lancisi,J. M. De Motu Cordis. 1728. § 44. (Opera, 1745. iv.)----Langrish, B., M.D. Modern Practice of Physic. 1735. p. 67.----Lungswaert, G. De Causa Rubedinis Sang. 1762.----Leacock, J. H. (Th.) De Haemoirhagia et Transfusione. 1816.----*Le Canu. Journ. de Pharm., N03. ix. and x. (1831.) Sur i'Analyse du Sang.—Journ. de Chim. Med. June, 1835. On Milky Serum.----Le Gallois. Le Sang est-il identique dans tous les vaisseaux qu'il parcourt? An xi.----Lee, R., M.D. Cyclop, of Med., art. Phlebitis and Phlebolite.----*Leeitwenlweck. A. van. Phil. Trans. 1674. pp. 22. 121; 1723. p. 436. Micros. Obs. on the Blood.—De Globilis in Sang., &c, in Epist. Posth. 1723. p. 426.----Leveling, H. P. Disquisitio crustae Inflam. 1772.----Levison, G., M.D. An Essay on the Blood, &c. 1776.----Leuret. (Th.) Sur l'Alter. du Sang; and Arch. Gen. de Med., xi. 683.----Lauretel Lassaigne. Rech. Phys. et Chim. sur la Digestion. 1825.----Lister. See Hodgkin.

Macaire et Marcet. Mem. de la Soc. Phys. et Hist. Nat. de Geneve, v. 400.-<---*Magendie, F. Precis Elem. de Phys. 4eme edit. 1834. p. 233. et Delille, Journ. de Phys. 1821.----Malpighi, M. De Viscerum Structural de Polypo Cordis. 1678.----*Marcet^C, M.D. Med. Chir. Tr. ii. 342. Anal, of various Animal Fluids.----Martini, S. Edin. Med. Essays. 1748. ii. 79.----Mayer, Professor. Zeitschrift fur Phys., erstes Heft. 1826. On the Coag. of the Blood in the Pulm. Vessels when the 8th pair of Nerves is divided.----*Mayo, H Physiology, 3d edit. 1833. p. 17.----Menghini, V. Bonon. Comment. (1747.) ii. pp. 11. 244 ; and iii. 475. De ferrearum particulis in Sang., <fcc.---■ Miry, J. Acad. des. Sc. de Paris, ii. 209. Obs. sur la Coleur du Sang. ----Metzger, J. D. De Rubedine Sang. 1781.----Meyen, F.J. P. Diss, de primis Vita? Phenom. et de Circ. Sang, in Parenchymata. 1826; and Isis, by L. Oken. 1828. p. 407.----*Michaelis, F. De partibus constitutives Sang. 1827 ; and Journ. fur Physiol, und Phys., by S. C. Schweigger. (1828.) iii. 94.----Moises, H. A Treatise on the Blood. 1746.----Monfalcon. Diet des Sc. Med. (1820.) art. Sang. —.—Montault. Journ. de Prog, des Sc. Med. i. 138. (1836.) Ant.- Path. du Sang.----Morgagni, J. B. De Sed et Causis Morb. Epist. i. v. and xxxi.----Moscati, P. Osserv. ed Esper. sul Sangue. 1776.---■ Moulin, A. Phil. Trans. 1687. p. 433. On the Quantity of Blood 'in Men, and on the Celerity of its Circulation.----*Muller, J. De Respir. Fcetus. (de Sang., pp. 41, 142.) 1823.—Isis, by L. Oken. 1824.— BIBLIOGRAPHY OF THE BLOOD. 143 Ann. des Sc. Nat. (1832.) xxvii.—Lettre addressee a l'Acad des Sc. (1832.) On the'Buffy Coat.

Nitzschke, C. Misc. Acad. Nat. Cur. 1670. p. 258. Lac. ex vasa profluens. ----Nysten, P. H. Rech. de Phys. et de Chim. Path. 1811.

Orjila et Andral. Diet, de Med. (1827.) art. Sang.—Arch. Gen. de Med. xvi. 16. (1828.) Nouveaux Mem. sur le Sang.consid. sous le rapport Med.-legale.----0'Shaughnessy, Dr. Report on the Chemical Path. of Cholera, p. 22.

Parent, A. Mem. de Paris. 1711. p. 24. Obs. sur les Cellules Poligones du Sang nou vehement tire.----Parmentier et Deyeux. Journ. de Phys. etde Chim. 1794.----Pasta, A. De Sang.&c. 1786.----Pitcairne, A., M.D. Dissert, de Sang. (Opera, ii.) 1722.----Piorry. Collect, des Memoirs. 1831; et Traite de Med. Prat. July, 1835. Sur l'Hemite ou l'lnflam. du Sang----Piorry et Mondezert. Journ. Hebd. (1834.) ii. 281. On the Buffy Coat.—Plenk. Hydrologia, &c. 1794. p. 42 et passim.----*Prevost, J. L. et L. A. Dumas. Bibl. Univ. des Sc. xvii. 302; and Ann. de Chim. et Phys. xviii. 280. (1821.) xxiii. 50, 90. (1823.) Examen du Sang et de son action dans les divers phenom. de la vie.—Ann. de Sc. Nat. 1824-5. Sur le Sang du Foetus.----Prater, H. On the Blood. 1832.----Priestley, J., LL.D. On Air. 1774. iii. 357 et passim.—Phil. Trans. 1776. p. 226. On Respir. and the Use of the Blood.----Prochaska, G. Disq. Anat.-Phys. Organismi Corporis ejusque processus vitalis. 1812.----Prout, W., M.D. Ann. of Philos. xiii. 12. 265. (1819.) On the Phenomena of Sanguification, and on the Blood in general.----Pyl, J. T. Dissert, de Rubedinis Sang. 1775.

Raygcr, C. Misc. Acad. Nat. Cur. 1675-6. p. 313. De sero lacteo V. S. extracto.----*Raspail. Repert. Gen. iv. parte 2. p. 148. (1827.) vi. parte 1. p. 135. (1828.) Sur la Struct, intime des Tissus et du Sang. —Sys. de Chim. Organ. 1833.----Rees, G. O. Analysis of the Blood and Urine, &c. 1836.----Reichel, G. G- De Sang, ejusque Motu Exp. 1767----Reichehn. Dissert, de Sang, &c. 1702----Reynaud. Journ. Hebd. de Med. ii. 84. (1834.)----Rhades, J. J Diss, de Ferro Sang. &c. 1753.----Ribes, F. Mem. de la Soc. d'Emul. viii. 604.----Richerand, A. Physiologie, 9eme edit., tr. by J. Copland, M.D. 2d edit. 1829. p. 232 et passim.—Mem. de la Soc. d'Emul. an iii. p. 296. Sur le Connex. de la Vie avec la Circulation.----Rivinus. Dissert, de Sang. Pravitate. 1702.----Roche, L. C. Nouvelle Elem. de path. Med. Chir. v.; et Journ. Hebd. de Med. 1833. Consid. sur les Alter, du Sang dans les Maladies.----Richoux, M. Diet, des Sc. Med. xvii. 123 ; and Diet, de Med. (1826.) art. Pathogenie.—Nouv. Bibl. Med. 1823 ; et Arch. Gen. de Med. xiii. 160. (1827.) Maladies avec ou par Alter, du Sang; also Journ. Hebd. ii. 530.----Rosa, M. Lettere Philos. in Giornale della Medicina. (1783-91.) i. 185----*Rose, H. Gilbert's Ann. der Physik und Chemie. 1826—Ann. de Chem. et Phys. xxxiv. 268—Edin. Med. and Surg. Journ. xxvii. 96-(1827.) On the'Presence of Iron in the Blood, &c.----Rose, L. G. De Motu Sang., &c [Haller. Disput. Anat. ii. 567.] 1668----Rouelle. Journ. de Med. xl. et xlvi, and Med. and Phil. Comment, by a Soc of Phys. in Edin. iii. 214- 144 HUNTER ON THE BLOOD. On the Nature of the Saline parts of th'c Blood----Rudolphi,C A Gundriss der Physiology,' 1821-9. Bde. 1. p. 159; and tr. by Dr. II. D. How. 1825. i. 132-

Sabatier, J. C. (Th.) Des Metastases purul. 1832.----Scheel, P. Die Transfusion des Blutes, kc 1802-3. ii. bde----Schmut, J. Misc. Acad. Nat. Cur. 1672- p- 166. De Lacte ex V. S. profluenti.----Schaper ./. E. De massae Sang, corpusculis- 1688----Schroeck, L. Misc. Acad. Nat. Cur. 1690. p. 452. De Sang. Albo.----*Schultz, K. H. Rev. Med. i. 136 et seq.; Archiv fur Anat. by J. F. Meckel. 1826; et Journ. de Prog. des. Sc. Med. v. On the Spontaneity of Motion in the Globules of the Blood.—Der Lebensprocess im Blute, &c. 1822.—Microsc Untersuchungen iiber des Herrn R. Brown, &c 1828----Schuz, G. P (Th.) Exp. circa Calor. Foetus et Sang- ipsius, 1799; et praes Autenrieth. 1799.----Schneider, C V- Dissert, de Sang. 1679----Schroeder. See Kolck----Schurig,M- Haematologia, &c. 1741----Schmidt, J. C- Ueber die Blutconer. 1822.----Schwencke, T. Haematologia, &c 1743----*Scudamore, C, M.D. Essay on the Blood. 1824.----Se galas dJEtchepare. Arch. Gen. de Med. xii. 103- (1826.)—Exp. sur le Sang, &c----Senac, P. Traite du Cceur. 1749. 1. 3. c. 4.--- Smith, H, M.D Essays Path, and Pract. on the Nature and Circulation of the Blood. 1761----Spitta, G. H. De Sang. Dignitate in Path, restituenda. 1625.----* Stevens, TV. On the Blood. 1832 ;—Lond. Med- Gaz. (1834.) xiv. 49 ; and Phil. Trans. 1835. p. 348. Observ.on the Theory of Respiration----Stahl, G. E. Dissert, de Sang. &c 1706.----Stoker, IV., M.D. Path. Obs. pt. i- 27. (1823.) ii. p. xiv. (1829.) Exp. on the Blood----Sturm, J. X- Dissert, de Sang. Colore. 1762____Soubeyan. Ann. ties Sc. d'Observ. ii. 133, 465.----Sydenham, T. Opera. 1726. § 6- c; 3.

Taylor, J. R. Lond. Med. and Phvs. Journ. lxvii. 187. (1831.) On the Buffy Coat of Blood----* Thackrah, C. T. On the BlOod. 2d. edit.. by Dr. T. C Wright. 1834----Thenard. L J. Traite de Chim 2eme edit. 1717-8. iii. iv. and tr. by Mr. Children.----Thomson, J. Lectures on Inflammation. 1813 passim.----Thompson, T. Syst.of Chera. 3d edit. 1807. v----Thouvenal,P. Sur le Mechanisme et les Produits de la Sanguification. 1777----Tiedemann, F. Physiologie. 1830. tr. by Drs. Gully and Lane. 1834----Torre, Abbe- 'Phil. Trans. 1765. p. 252. Micros. Observ. on ihe Blood----Traill, T. S- Edin. Med. and Surg. Journ. xvii. 235, 637. (1823.) ; and xxiv. 421. (1825 ) On Milky Serum.----Treviranus, G- R. Die Ercheinungen und Gesetze des organischen Lebens, &c. 1831.----Treviranus, L. C. Vermischte Schriften, anat. und phys. Inhalts. 1817- Bde. i. 122----Trousseau et Rigot. Arch- Gen- de Med. xii (1826.) xiv. 321. (1827.) Sur la Color, cadaveriques des Arteres et des Veines.----*Turner, E., M.D- Elem. of Chemistry. 4th edit. 1833. p. 287.

Valli, E Discorso sop. il Sangue, &c-1782----Vauquelin. Ann. de Chim. i. 9.(1816-) Sur le principe Col-du Sang----Velpeau, A-J^.M- Arch. Gen. viii. 306. (1825.)----Verhelst, T Essai Phys. sur la Sanguification. 1820----Fieussens, R. Phil. Trans. 1698- p. 224- On the Human Blood----Villerme, L R- Diet, des Sc. Med. art Serosite- OF THE VASCULAR SYSTEM. 145 (1821.)----lines. Lancet, xi. 294.423. (1826-7.) On the Buffy Coat- ----Vogel. Ann. de Chim- et Phys. lxxxvii. 215. (1813.) De l'Exist du Soufre dans le Sang;—ib. xciii- 71. (1815.) De l'Exist. de l'Acid Carb. dans le Sang.

Waldschmidt, J. J. Misc. Acad. Nat. Cur. 1671. p. 312. Ex. Vena Sanguis albus eductus.----Waller, C. Obs. on Transfusion. 1825.----Wedel, G. W. Misc. Acad. Nat. Cur. 1675-6. p. 1. De Conquassatione Sang. —ib. 1686. p. 323. Sanguis per micros, examinatus, ramosus----- Wedemeyer, V- G. Ueber das Nervensystem und die Respiration. 1817 : and Archiv fur Anat. und Phys. by T. F- Meckel. 1818. p. 356.---- Weiss, E. Acta Helvet. iv. 351. (1760.) Obs. sur les Glob, du Sang. ----Wells, W. C, M.D. Phil. Trans. 1797- p. 416. Obs. and Exp. on the Colour of the Blood.----Whiting. Dissert. Med. de Sang. iEgrorum. ----Whytt, R., M.D. Works. 1768. p. 26. On the Blood, et passim. ----* Williams, C.J. B., M.D. Med. Gazette, xvi. 718 et seq. (1835.) Obs. on the Blood, &c.----Willis, R., M.D. Opera. 1676. passim. ----Wilson, J. Lect. on the Blood. 1819.----Wollaston,W. H, M.D. Phil. Trans. 1811. On the want of Sugar in Diabetic Urine.

Zetzell, P. Svenske. Veten- Acad. Handl. 1770. p. 235- Phys. Undersoekning om tre arter Blod-watten. CHAPTER II.

§ 1. General Observations on Muscular Contractions and Elasticity.

It is not my present intention to explain all the circumstances connected with muscular contraction and relaxation, nor that other power of action introduced into an animal body, called elasticity,* I propose only to state a few of the facts which throw some light upon the vascular system, by showing that there is in vessels a power of muscular action, and that the cooperation of elasticity is also necessary to their function. These may likewise assist in explaining the manner in which the two powers are combined. I may, however, occasionally be led to mention causes and effects which cannot be immediately considered as applicable to the vessels themselves, though they will render many of the phenomena in the vascular system more easy to be understood.

* [See Croonian Lectures on Muscular Motion, &c, in the succeeding volume of this edition.] 13* 14G HUNTER ON THE BLOOD. The common action of a muscle, from which its immediate use is derived, is its contraction; and the effect produced by it is that of bringing the origin and insertion, or the parts which it is fittedI to move, nearer to each other;* which is universally the case whether the muscle is straight, hollow, or circular. It is likewise necessary that a muscle should relax, or be capable of relaxation ; a condition which allows it to be stretched, by permitting the parts acted upon to recede from each other. Muscles, in common, probably, with every other part of the body, have a power of adapting themselves to the necessary distance between origin and insertion, in case an alteration has taken place in the natural distance; and I have reason to believe that, under certain circumstances, they have a power of becoming longer, almost immediately, than they are in the natural relaxed, or even the natural elongated state of their fibres. Th;s opinion will be best illustrated in inflammation. Muscular contraction has been generally supposed to arise from some impression, which is commonly called a stimulus; I doubt, however, of an impression bemg always necessary ; and I believe that in many cases the cessation of an accustomed impulse may become the cause of contraction in a muscle. The sphincter iridis of the eye contracts when there is too much light, but the radii contract when there is little or no light, f I can even conceive that a cessation of action requires its stimulus to produce it, which may be called the stimulus of cessation; for relaxation is not the state into which a muscle will naturally fall upon the removal of a continued stimulus ; a muscle remaining contracted after absolute death, when the stimulus of relaxation cannot be applied ; so that a musr.le can as little relax after death as it can contract.;}; If a stone is raised, and the raising power removed, it falls ; but it would not fall if not acted upon. When it has fallen it lies at rest; but so it would have done when raised, if gravitation would have allowed it. The stone is passive, and must be acted upon. Whatever * I do not here consider the circumflex tendons ; for, by the origin and insertion, I mean the muscular ends of the fibres. f [Dr. Parry objects to this illustration, and thinks that the. radii of the irisrestore themselves by their simple tonicity, in the same manner as other muscles. It may be observed, that the fact of the muscularity of the iris, which is here presumed from analogy by Mr. Hunter, has been since directly proved by the observations of Bauer and Jacob (Phil. Trans. 1822), and indirectly by Berzelius, who found that the iris possesses all the chemical properties of muscle. Dr. Roget also has informed us that the iris of his eye is partly under the influence of the will; and Mr. Mayo, that in some animals it instantaneously contracts on any mechanical irritation of the third pair of nerves (op. cit., p. 291); phenomena which are obviously only referrible to a muscular structure.] X [Muscles which have long been contracted lose all disposition to relax, as may be observed in Fakirs and other religious visionaries, who compel themselves to remain in constrained positions of the body for a long time together, and in the contractions which follow diseases of the joints. Even a powerful grasp of the hand, continued only for a few minutes, is recovered from with difficulty. That peculiar tetanic spasm of the lower extremities which is induced by injecting a solution of opium into the stomach of a frog, is not relaxed by a division of the spinal marrow above the origin of the lumbar nerves.] OF THE VASCULAR SYSTEM. 147 becomes a stimulus to one set of muscles, becomes a cause of relaxation to those which act in a contrary direction ;* and whatever becomes a stimulus to one part of a muscular canal, where a succession of actions is to take place, becomes also a cause of relaxation in the part beyond it, as in an intestine. Muscular contraction, in some of the involuntary muscles, does not constantly arise from immediate stimuli, as in the sphincters ; for the sphincter ani contracts whenever the stimulus of relaxation is removed, which may be said to produce the stimulus for contraction. Muscular actions have been divided into the voluntary, involuntary, and mixed, which is only dividing them according to the different natural modes of stimuli or causes of their action: to these a fourth might be added, where the actions are in consequence of accidental stimuli or impressions, to which both the voluntary and involuntary muscles are subject, viz., such as arise from affections of the mind,! or are the immediate effects of violence. The involuntary contraction should be first considered, as the more necessary operations of the machine are carried on by it; for the machine could even exist independent of any voluntary contraction : but it could not go on if left wholly to the voluntary contraction of the muscles, unless we were endued with innate ideas capable of producing a will. This involuntary contraction is very extensive in the system, and is employed in carrying on a number of operations, of which the circulation is one ; and which may be said to be, in a great measure, the oeconomy of the animal within itself. The mixed kind of contraction is most to our present purpose, and is of two kinds, though it has been in general supposed to be of one kind only, and that belonging solely to the muscles of respiration, as being in them the most conspicuous. But, in fact, we find another mode of involuntary actions in other muscles of the body, where it answers very useful purposes. In these the involuntary contraction may be reckoned the natural state; and it is a kind of permanent contraction, these muscles only relaxing occasionally, by which means parts are sustained or supported: the voluntary contraction of such muscles is also only occasional. All sphincter muscles in some degree partake of this power, and therefore should be called muscles with power of occasional relaxation. For although many circular muscles may not have these mixed contractions, as the orbicularis palpebrarum, yet that muscle has a disposition to contract peculiar to itself. Its relaxation is to be reckoned of the active kind, which may be called the relaxation of watchfulness; and it is when tired of this species of action thatit contracts, which, on the contrary, may be called the contraction of sleep: or it may

* This might be called a sympathetic stimulus, and is that which regulates the actions of the whole machine, and which I have called, in another place, the stimulus of necessity. ■j- Mind and will are often blended together, but will has nothing to do here. 148 HUNTER ON THE BLOOD. be considered as an elongator muscle to the levatar palpebrse, with a disposition to remain relaxed while that muscle is contracted, but contracting when the elevator is tired. The natural contraction of the orbicularis muscle is involuntary, the relaxation, both natural and occasional, is involuntary ; but it has likewise a voluntary contraction and relaxation, which can be made to exceed the involuntary, resembling what is inherent in all the sphincters.* Sphincter muscles, as those of the anus and urethra ; and probably the expulsatores seminis, and crura of the diaphragm, have both a voluntary and involuntary contraction. In the two sphincters of the anus and urethra this is evident; and the involuntary contraction in these muscles I have called sphinctoric. The sphincter ani, possesses it to a degree just sufficient to resist the pressure of the"air and faeces, while the parts above are inactive, preventing the escape of these, till they give the stimulus for expulsion, and then an involuntary relaxation naturally takes place, similar to what happens in muscular canals. The sphinctoric contraction resembles in its effects that produced by elastic ligaments in other parts of the body, which action may be called contractile elasticity, as bringing back the parts to a certain necessary state, and retaining them there. But elasticity would not here have answered all the purposes, since, as it has no relaxing power, more force would have been required to overcome its resistance in the expulsion of the faeces than the gut above could have been able to exert. But the sustaining power being muscular contraction, a relaxation or cessation of that contraction during the time of expulsion leaves nothing for the faeces to do. but, by means of the action above, simply to dilate the relaxed parts. There is, likewise, in these muscles a still further power of contraction, which is produced by the will, and for the purpose of giving, on particular occasions, greater force than what is commonly necessary. The voluntary action of these muscles is therefore, we find, more powerful than the involuntary; but upon the whole I think we have reason to suppose that the involuntary muscles are much stronger

* [I see no reason for supposing that the orbicularis is different from the other sphincters, or that it has a disposition to contract peculiar to itself: it is only peculiar in being antagonized by the levator palpebrarum, which is a common voluntary muscle. The tone of muscles, to which may probably be referred the ordinary contraction of the sphincters, is that slight tendenoy to contract in the longitudinal direction of the fibres by which they adapt themselves to the variety of their situation. Now this tone is in great part lost in the extremities and common sphincters when the nervous supply is cut off, although it seenu doubtful in what degree it is dependent on the nerves in common cases, so as to relax when an antagonist muscle comes into play. The tonic retraction of a divided muscle is equally energetic when the nerves which supply that muscle are divided as when they are entire; and fish are more effectually crimped when they are first knocked on the head. The heart of a turtle, recently plucked from the chest and deprived of blood, actively dilates and contracts ; which would lead us to believe that the same action more or less takes place in all the muscles,— the relaxation of a muscle being not merely a cessation of action, but an active dilatation, requiring a stimulus for its production.] OF THE VASCULAR SYSTEM. 149 than the voluntary. Can we believe that so thin a muscle as the colon of a horse could squeeze out its contents, consisting of a column of dung about eight inches in diameter, if those involuntary muscles had no more strength than the muscles of an extremity 1 When we see the bladder of urine throwing out its contents through a large tube, to a distance, perhaps two yards beyond its extreme end, we must suppose a much greater force exerted than could belong to any such quantity of voluntary muscle. For I believe that by grasping the bladder with both hands we could not make the water flow out to an equal distance.* It may be here observed, that the power of involuntary contraction commonly remains longer than that of the voluntary, though I believe not in all instances ; which difference produces a greater variety in the former than in the latter. Thus the muscular action of the arteries is longer retained than that of the heart. Elasticity is a property of matter (whether animal or not) which renders it capable of restoring itself to its natural position, after having been acted upon by some mechanical power, but having no power of action arising out of itself. This is exactly the reverse of muscular contraction. Muscles, as has been already observed, have the power of contraction and of cessation, which last is called relaxation, but not the power of elongation, which would be an act of restoration, such as exists in elasticity. A muscle, therefore, has the power of action within itself, by which it produces its effects, but is obliged to other powers for its restoration, so as to be able to act again; whereas elasticity is obliged to other powers to alter the position of the parts, so as to require recovery or restoration: but this it is capable of doing itself; and by this power it produces its effects, becoming a cause of motion in other bodies. A body possessed of this property, when brought from the state of rest, is always endeavouring to arrive at this state; which it also endeavours to preserve; and it is capable of supporting itself in this state in proportion to the degree of elasticity which may belong to it. The action of electricity is continual, and its immediate effects are produced whenever the resistance is removed, by which it may be distinguished from other powers. Elastic matter can either be extended beyond its state of rest, or brought within it. Thus a

* [It may be doubted whether the colon or the bladder ever act alone. Certainly the diaphragm and abdominal muscles cooperate in all ordinary cases. In injuries of the back, the rectum is frequently able to retain and expel the fapces, although the bladder is perfectly incapable of evacuating the urine. Now they both derive their nerves from the same part, but there is this difference between them,—the sphincter ani being relaxed, the fibres of the rectum have no difficulty in expelling its contents, but the urine has to be forced through a long and narrow canal at the same time that the bladder is generally much distended before the nisus arises, in consequence of which the muscle of the bladder acts to the greatest possible disadvantage; for the aperture and compressing force being given, the rapidity and projection of the stream will be inversely as the superficies of the containing vessel.] 150 HUNTER ON THE BLOOD. spring being bent, its concave side is brought within this state, and the convex side is carried beyond it: when under these circumstances it is left to itself, both sides endeavour to restore themselves. The power of an elastic body is permanent, always acting with a force proportioned to the power applied, and therefore reacts as the body is elongated, bent, or compressed ; but this is very different from the action of a muscle, as this last may act with its full force, or only part, or not at all, according to circumstances. Elasticity,* which has the power of resisting the action of other parts, as well as of restoring the substance endowed with it, when forcibly removed from a state of rest, is introduced into an animal body, in order to cooperate in many respects with the muscles, and so to act as to restore or fit them for a new action, becoming in many cases antagonists to the muscles, which will be described when we speak of the combination of the two.

§ 2. General Observations on the Elongation of relaxed Muscles.

Everything in nature that has the power of action has two kinds of motion exerted alternately, and a state of rest. Of the former, the one may be called the active, the other the state of recovery. In a muscle, theactive is the state of contraction, the other the state of relaxation : the state of rest is merely the state of inaction. The contractile state of a muscle, as well as the relaxed, arises from a power inherent in itself; but the recovery or elongation must depend on some other power. Simple relaxation of a contracted muscle is not sufficient to enable it to produce another requisite effect; it is, therefore, necessary that there should be an elongator equal to the quantity of contraction intended to bo produced: and as no muscle has the power of extending itself into what I shall call the state of recovery, an elongator of some kind or other is required, to enable every muscle to produce its effect, by a renewal of contraction. This, although in some respects similar to the winding up of a clock, in others differs materially from it. For the muscle being capable of relaxing itself, there is no resistance to overcome, except the vis inertiae and friction of the matter to be removed: whereas in the clock, the power that winds it up must be greater than the spring or weight, to be capable of overcoming the gravity of the weight, or the elasticity of the spring, together with the vis inertiae. The elongation of muscles is not the immediate cause of their relaxation, but the effect of a contrary and necessary motion of the

* It is to be observed, that elasticity in animals does not, like muscular contraction, depend on life, an elastic body possessing that quality as perfectly after death as before. Elasticity admits of two actions ; a contraction when the substance is extended beyond the natural state, and an extension when it is compressed within it: both these are possessed by the elastic parts which compose the vascular system; whereas muscles have but one action, or, at least, but one which can produce an immediate effect, and that is contraction. OF THE VASCULAR SYSTEM. 151 elongators, by which they are recovered so as to be enabled to renew their action with effect. The elongators, or powers which enable muscles to recover themselves, are not always muscular, for when simple elongation is required, it is effected by other means, as elasticity, which is the case in part in the blood-vessels ; and sometimes by motion in matter foreign to the body, yet propelled either by muscles or elasticity, as is also the case in blood-vessels. The elongators may be divided into three kinds, with their compounds. The first kind is muscular, and these may either act immediately, or they may act on some other substance, by which action that substance becomes the immediate cause of the elongation. Those which act immediately, and become elongators to other muscles by their contraction, are in turn elongated by the contraction of these very muscles, to which they served as elongators, the two sets thus becoming reciprocally elongators to each other. This is the case with the greater part of the muscles in the body, and in some muscles, as the occipito-frontalis, two different portions are reciprocally elongators; yet these may strictly be considered as two muscles; for although there is no interruption, in the tendon they move the same part in two opposite directions, like distinct antagonist muscles. These reciprocal elongators, by their mutual action on each other, bring out a middle state between the extremes of contraction and elongation, which is the state of ease or tone in both. This appears not to be so much required for the ease of the part moved, as for that of the relaxed muscle,* either extreme of motion leaving the muscle in an uneasy state. We find, therefore, that as soon as any set of muscles cease to act, the elongators, which were stretched during their action, are stimulated either by this cessation, or by the uneasy state into which the parts moved have been put, to act in order to bring these parts into a state the furthest removed from the extremes which were uneasy, and by which the stimulus arising from both is equally balanced. This, however, can only happen in such parts of the body as are furnished with muscular elongators; where these are wanting, the muscles of the part having but one office, their state of ease is that of simple relaxation, as they can have no middle state from the action of antagonists ; but such are commonly muscular parts, qr so constructed as not to be thrown into an uneasy position by the action of their muscles. I suppose, however, that the elongated state of a muscle is an uneasy state: a muscle, therefore, that is stretched, although in a relaxed state, is uneasy, and will contract a certain length, to what is probably the middle state. Still it is necessary that such parts as are simply muscular, and have no antagonist muscles appropriated immediately for such

* [The reading of this passage in all the editions, is " for the ease of the relaxed muscles, as for that the part moved," the reverse of which seems to have been intended by the author.] 152 HUNTER ON THE BLOOD. purposes, should have their muscles elongated ; this is still performed by muscles, but in a secondary way; for instance, by a succession of actions in different parts, each performing the same effect, and the last action becoming an antagonist to the succeeding. This second mode of elongation takes place in all the. muscles which assist in forming canals. In them the muscles, if once contracted; cannot be elongated, or the part dilated again, unless by the contraction of some other part of the canal, propelling its contents into the relaxed part, and by that means serving as an elongator. This, in some instances, goes on in regular succession, as we know the dilatation of the fauces to be occasioned by the action of the mouth and tongue; that of the oesophagus, by the contraction of the fauces; of the stomach, by that of the oesophagus; the upper part of the intestines, by the stomach, and so on; the successive contractions of the last dilated parts pushing on the contents, and in that manner becoming elongators of the muscles next in succession of action. A first propelling power, such as a heart, could in these instances have had but little effect, and would even have been unnecessary; for as there must be a succession of contractions and dilatations, its power would soon have been lost. This mode of propelling substances through canals, as stated above, would probably have been too slow for the circulation in many animals, but I believe it is very much the case in others. The elongation of the muscles of the bladder, from the distention of urine, becomes the means by which they are excited to recover themselves so as to renew their action, and may be referred to the same general head. The third kind is by means of elastic substances, which render the combined actions produced by muscular contraction and elasticity more complicated. Elasticity we find to be introduced both as an assistant to the contraction of the muscles, and as an antagonist or elongator; the natural position being that which is produced by the elasticity. Thus we see elasticity combined with muscular action assisting in the contraction of muscles on one side, and likewise performing the office of elongators or antagonists on the opposite, by bringing parts which have been moved by muscles back into their natural position. Such parts, too, as have yielded to the action of some other power, as gravitation, are brought back into what may be called a natural state, and are retained there by elasticity, till that power is again overcome by another, as in the necks of some animals. We may hence see that the application of those powers is twofold; one, where the muscles and elastic substances assist each other; the second, where they are antagonists, the elastic being neither assisted by the muscular parts, nor the muscular by the elastic; for many parts of the body are so constructed as to admit of but one kind of muscular action, the other action arising from elasticity alone; it being necessary that such parts should have a determined or middle state, though not intended as a state of ease. OF THE VASCULAR SYSTEM. 153 Of this kind are the blood-vessels, trachea, bronchia, the ears of animals, etc., in which, therefore, elasticity is introduced to procure that determined state, and is chiefly employed where the middle state is much limited. For it is to be observed, that the middle state, when produced by muscular action, has not commonly a determined point of rest, but admits of considerable latitude between the two extremes, except in the sphincters. Where it is produced by elasticity, it is always more determined, provided the elasticity has sufficient power to overcome the natural or accidental resistance; and where that is the case, we must suppose that a state, in some degree determined, was necessary to such parts. But where the elastic power is not sufficient to overcome the natural, or accidental resistance, then it is assisted by the muscular, which forms one of the compounds of the three modes of elongation, instances of which we have in many joints. The relaxed state of a muscle would appear in general to be the most natural; but to this there are exceptions, a degree of contraction appearing natural to some muscles.* The face, for instance, is a part where the action of the muscles on one side influences the position of the parts on the other side, a circumstance, perhaps, peculiar to the face; here, therefore, the muscles bring and keep the skin in one position, till altered by an increased action in soine other muscle; and when this increased action ceases, the constant and natural contraction of the whole (similar to that of the sphincter) immediately takes placet Sphincter muscles are the most remarkable instances of this, being always above three parts contracted-! The constant and regular degree of contraction in those sphincter muscles, serves the purposes of elasticity, and may have superior advantages, as we know that they have a power of relaxing when their elongators act, which no elastic substance can have. Hence we see, that where a continued action only is wanted, there is elasticity ; where an alternate action and relaxation, there is the action of muscles; where only an occasional relaxing power is required, there are muscles under certain restrictions; and where a constant power of contraction is necessary, but which is occasionally to be overcome by muscles, there are introduced both elasticity and muscular powers, cooperating with each other in their actions. Where constant action is not necessary, muscles alone are employed, as in the greater number of moving parts in most animals ;

* [I apprehend that all muscles, without exception, are endued with a tonic power of contraction, but in very different degrees. In the involuntary muscles, as the stomach and heart, it is scarcely at all visible; but it is highly developed in most of the sphincters.] | As a proof that this is muscular contraction, and not elasticity, we find that the face in a dead body does not keep its natural form, nor resume it when lost. X The parts supplied with sphincters do not contract after being dilated in the dead body, which they certainly would do if the contraction in the living body had arisen from elasticity. 14 154 HUNTER ON THE BLOOD. and where any position is required to be constant, and the motion only occasional, from being seldom wanted, there elasticity alone is employed for the purpose of constant position, and muscles for the occasional action.* When a position is to be pretty constant, and yet elastic substances are not employed, we have then muscles endowed with the power of constant contraction to a certain degree, but capable of either relaxation, or greater contraction, as in the sphincters. We find, therefore, that in many parts of an animal body fitted for motion, a tolerably constant position is necessary, at the same time that an occasional self-moving power is also wanted, to serve as a sort of auxiliary to the performance of the necessary action. For such occasional actions, muscles, assisted by elastic substances, are employed, the elastic power easing the muscles in the fixed position, and the muscular giving the increased occasional action; and in other parts of the body, where a more constant action was wanted, and could not be completely obtained by elasticity, there are to be found muscles endowed with the property of both permanent and occasional contraction. The elastic power is very remarkable in such parts of an animal body as require a constant effort to support them, elasticity being introduced to act against the power of gravitation, as in the necks of animals whose heads are held horizontally, or beyond the centre of gravity. This is effected by an elastic ligament, and is strikingly illustrated in the camel, whose neck is long. Between the vertebras of the neck and backs of fowls are placed elastic ligaments for the same purpose; the wings of birds and bats are also furnished with them, by which means they are retained close ro the body when not used in flying. On the abdomen of most quadrupeds are likewise to be found elastic ligaments, especially on that of the elephant, which affords a constant support to the parts in their horizontal position ; and even the cellular membrane of the elephant has a degree of elasticity much above what is generally met with in cellular membranes. Hence there is less expense of muscular contraction in such parts. The trachea and its branches are instances of these two powers, being composed of cartilages, muscles, and membranes; the proportion of muscular substance, however, is small, the muscles which act principal!}' upon this part being those of respiration ; but the tendency of the action of the proper muscles of the trachea is to compress and alter the size of the trachea; this is counteracted by the elasticity of the cartilages and membranes exerting a constant and regular endeavour to keep it of one certain size. The external ears of many animals furnish us with another

* Some bivalves (as the oyster) have a strong muscle passing between the shells for closing them occasionally ; but for opening them no muscles are made use of, as this is performed by an elastic ligament in the joint of the two shells, which is squeezed, when shut, by the contraction of the muscle; and when the muscle ceases to contract, the elasticity of the ligament expands it, so that the shell is opened. OF THE VASCULAR SYSTEM. 155 instance of the joint application of these two powers, for being chiefly composed of elastic cartilage, they retain a general uniformity of shape, although that is capable of being altered occasionally by the action of muscles. It is however to be observed, that in all cases where these two powers are joined, the muscular, as it can always act in opposition to the' elastic, must be the strongest, and capable of being carried further than the other; it therefore must always be proportionably stronger than it otherwise need to have been. Parts in which these two powers are employed are capable of being in either of three states,—the natural, the stretched, and the contracted ; but in some parts the natural state may coincide either with the stretched or contracted, and consequently such parts are only capable of being in two states. The natural state is produced by the elastic power simply; the contracted is the effect of the muscular power alone; and the stretched is produced either by some foreign force, or body protruded, which may be effected by a muscular power.

§ 3. Of the Structure of Arteries.

The arteries in an animal, as far as we can examine them, are endowed with the property of elasticity, the use of which we perceive in the action of those parts; and this power is at all times demonstrable, while the muscula'r has been by some overlooked, by others denied, and has only been asserted by others as appearing necessary by reasoning from analogy. The quantity of elasticity in any artery on which an experiment can be made is easily ascertained, as it only requires the application of an opposing force to prove both its power and extent. But it will appear from experiment, that the power varies according to the distance from the heart, being greatest at the heart: while probably the extent may be the same in every artery. To endeavour to ascertain the elasticity of arteries, I made comparative experiments on the aorta and pulmonary artery. Having cut off a portion, of about an inch in length, from the ascending aorta, at half an inch above the valves, and having slit it up, it measured, transversely, two inches and three-quarters, but when stretched to its full length, three inches and three-quarters, having gained rather more than one-third, and having required a force equal to the weight of one pound ten ounces to produce this effect. A similar section was made of the pulmonary artery in the same subject, which measured two inches and a half, transversely; and when subjected to trial in the same manner, was stretched to three inches and a half, being rather more in proportion than the aorta; so that the pulmonary artery appears to have rather more elasticity than the aorta. It is not impossible that this difference might have arisen from the aorta having lost some of its elasticity by use; for although I chose for my experiment the arteries of a young man, where I con- 156 HUNTER ON THE BLOOD. ceived them to be perfectly sound, yet if there could have been any diminution of the elasticity from use, it would be most considerable in the aorta. These experiments were made on different arteries with nearly the same result, and seemed to prove that there was almost the same extent of elastici'y, though not the same powers. An artery being composed of an elastic and inelastic substance, its elasticity is not altogether similar to that of a body which is wholly elastic. There is an effect produced from stretching it that is expressive of the nature of both these substances, till it gives way or breaks; for an artery has a check to its yielding to so great a degree, and is stopt at once, when stretched to a certain point,* which check is occasioned probably by the muscular, together with the internal inelastic coat.f To prove the muscularity of an artery, it is only necessary to compare its action with that of elastic substances. Action in an elastic body can only be produced by a mechanical power; but muscles acting upon another principle can act quickly or slowly, much or little,according to the stimulus applied; though all muscles do not act alike in this respect. If an artery is cut through, or laid bare, it will be found that it contracts by degrees till the whole cavity is closed; but if it be allowed to remain in this contracted state till after the death of the animal, and be then dilated beyond the .state of rest of elastic substances, it will only contract to the degree of that state; this it will do immediately, but the contraction will not be equal to that of which it was capable while alive. The posterior tibial artery of a dog being laid bare, and its size attended to, it was observed to be so much contracted in a short time as almost to prevent the blood from passing through it, and when divided the blood only oozed out from the orifice. On laying bare the carotid and crural arteries, and observing what took place in them while the animal was allowed to bleed to death, these arteries very evidently became smaller and smaller. When the various uses of arteries are considered, such as their forming different parts of the body out of the blood, their performing the different secretions, their allowing at one time the blood to pass readily into the smaller branches, as in blushing, and at another preventing it altogether, as in paleness from fear: and if to these we add the power of producing a diseased increase of any or every part of the body, we cannot but conclude that they are possessed of muscular powers. The influence of the heart in the body, like that of the sun in the planetary system, we know extends to every part; all the parts of

* This gives a determined size to an artery. f [Thus Poiseuille, by direct experiment proved that the force of reaction excited by the distention of a recent artery was greater than the force used to distend It, and greater also lhan an artery could exert some time after death, before decomposition had commenced. This is only to be accounted for by its muscularity. (Journ. de Phys. par M. Magendie, viii. 272.)] OF THE VASCULAR SYSTEM. 157 the vascular system being supplied according to the necessity it has ; though every part is not equally endowed with power, or disposition to make use of that power. The arteries, upon the whole, may be said to possess considerable living powers, and to retain them for a long time. This is evident when we observe what must happen in transplanting a living part of one body with an intention that it should unite with another body and become a part of it; the part transplanted must retain life till it can unite so as to receive its nourishment from that into which it has been inserted. It is, however, to be supposed that in such situations life can be retained longer than in others, although it is well known that it is preserved in the vascular system, even when there is no collateral assistance. I found in the uterus of a cow, which had been separated from the animal above twenty-four hours, that after it had been injected and allowed to stand another day, the larger vessels had become much more turgid than when I first injected them, and that the smaller arteries had contracted so as to force the injection back into the larger.* This contraction was so obvious that it could not but be observed at the time, which was -forty-eight hours after the separation from the body of the animal. This shows, too, the muscular power of the smaller arteries to be superior to that of the larger, and that it is probably continued longer after the separation from the body; a property which the involuntary muscles possess to a degree greater than the voluntary, in the former of which classes the muscular structure of the arteries is to be considered. To ascertain how long the living power existed in any artery after separation from the body, or perhaps, to speak more properly, after that communication with the body was cut off, by which we have reason to suppose life to be continued in a part, I made the following experiments, for which I chose the umbilical arteries, because I could confine the blood in them, and keep them distended for any length of time. In a woman delivered on the Thursday afternoon, the navel-string was separated from the foetus; it was first tied in two places and cut between, so that the blood contained in the cord and placenta was confined in them. The placenta came away full of blood; and on Friday morning, the day after, I tied a string round the cord about an inch below the other ligature, that the blood might still be confined in the placenta and remaining cord. Having cut off this piece, the blood immediately gushed out, and, by examining the cut ends of the cord, I attentivelv observed to what degree the ends of the arteries were open; and the blood having now all escaped from this portion, the vessels were left to contract with the whole of their elastic power, the effect of which

* [The same fact is also proved by the great difficulty of thoroughly injecting the capillaries in a recently killed animal, so as to make the injection pass forwards into the veins. Thus also Wedemeyer found a much greater force requisite to force an irritating fluid, such as dilute alcohol or vinegar, through the capillaries of ihe living animal than when he employed a bland fluid 1 ° 14* 158 HUNTER ON THE BLOOD. is immediate. Saturday morning, the day after this last part of the experiment, having examined the mouths of the arteries, I found them closed up, so that the muscular coat had contracted in the twenty-four hours to such a degree as to close entirely the area of the artery. That same morning I repeated the experiment of Friday, and on Sunday morning observed the result of this second experiment to be similar to that of the former. On this morning (Sunday) I repeated this experiment the third time, and on Monday observed that the result had not been the same as before, the mouths of the arteries remaining open ; which showed that the artery had become dead. There was but little alteration perceived in the orifices of the veins in all the experiments. These experiments show that the vessels of the cord have the power of contraction above two days after separation from the body. Having given a general idea of muscular action, including muscular relaxation, together with the union of the muscular and elastic power in an animal, I shall now apply them to the arteries. There are three states in which an artery is found, viz., 1st, the natural pervious state; 2d, the stretched; and 3d, the contracted state, which may or may not be pervious. The natural pervious state is that to which the elastic power naturally brings a vessel which has been stretched beyond or contracted within the extent which it held in a state of rest. The stretched is that state produced by the impulse of the blood in consequence of the contraction of the heart; from which it is again brought back to the natural state by the elastic power, perhaps assisted by the muscular. The contracted state of an artery arises from the action of the muscular power, and is again restored to the natural state by the elastic. It has been shown that certain muscles have both a voluntary and involuntary contraction, and that in some of these the involuntary action having brought the part to the necessary position, supports it in that state till it be either necessary for the muscle to relax, or for the voluntary action to take place; instances of which I have given in the sphincter muscles. I shall now endeavour to show that the arteries have a middle state, but that in them the power of bringing the coats into a certain position, and sustaining them in it, is not the effect of a muscular but of an elastic power: and that the muscular action, both in contraction and relaxation, is involuntary. In parts endowed with considerable elastic powers, although not apparently muscular, as many arteries, but which we yet know, from other modes of information, to be possessed of muscular power, elasticity is so combined as to produce a middle or natural state, by acting to a certain degree only as an elongator of the muscular part in some of its actions.* These two powers, muscular and

. * We can hardly suppose that the muscular coat of the artery assists the elastic in bringing it to the middle state when already contracted within it. OF THE VASCULAR SYSTEM. 159

elastic, are probably introduced into the vascular system of all animals, the parts themselves being composed of substances of this description, together with a fine inner membrane, which I believe to be but little elastic, and this membrane is more apparent in the larger than in the smaller ramifications. When we consider the construction and use of the arteries, we must at once see the necessity of their having these two powers, although in the greatest number it is impossible to give clear ocular demonstration of the existence of distinct muscular fibres. But still, as arteries are evidently composed of two distinct substances, one of which is demonstrably elastic, and we know them likewise to be certainly endowed with the power of contraction peculiar to a muscle, it is reasonable to suppose the other substance to be muscular; 1 shall endeavour also to prove its existence in such vessels, from their having a power of contraction in the action of death. As the human body is always alluded to in this account, I shall found my experiments and observations on such animals only as have a similar structure; for in other animals, as the turtle,.alligator, &c, we can plainly discern muscular fibres, the insides of the arteries and veins in these animals being evidently fasciculated. Every part of the vascular system is not equally furnished with muscular fibres; some parts being almost wholly composed of the elastic substance, such as the larger vessels, especially the arteries, in which, were they equally muscular with the smaller vessels, the existence of muscular fibres might be more easily proved. Neither does the elastic substance equally prevail in every part, for many, especially the smaller arteries, or what have been called the capillary vessels, appear to be almost entirely muscular; at least I am led to think so from my own observations and experiments on this subject. From these experiments I have also discovered that the larger arteries possess little muscular powers; but that as they recede from the heart towards the extremities, the muscular power is gradually increased, and the elastic diminished. Hence I imagine there may exist a size of vessels totally void of elasticity: but this I should conceive to be in the very extreme parts only. For it is to be observed that every portion of an artery, of a considerable size, is capable of assuming the middle state, which state must be referred to the elastic power. The greatest part of the arterial system evidently appears to be composed of two substances, which structure is most remarkable in the middle-sized arteries, where the two substances are more equally divided, and where the size admits of a visible distinction of parts. The best method to see this is to cut the vessels either across or longitudinally, and to look upon the edges that have been cut.*

* [The reader is probably aware that the nature of the proper arterial tissue has formed one of the most contested points in all physiology. The fibrous coat of arteries, according to Meckel, is easily separable into different transverse slightly oblique layers, which resemble one another precisely in structure, but 160 HUNTER ON THE BLOOD. If the aorta be treated in this way, we shall find that though it appears to be composed of one substance, yet towards the inner surface it is darker in colour, and of a structure which differs, although but in a small degree, from that of the outer surface. If we proceed by this mode of investigation, following the course of the circulation, we shall find that the internal and external parts become evidently more distinguishable from each other : the internal part, which is darker, but with a degree of transparency, begins almost insensibly in the larger vessels, and increases proportionably in thickness as the arteries divide, and of course become smaller, while the" external, being of a white colour, is gradually diminishing, but in a greater degree, according to the diminution of size in the artery, and of the increased thickness of the other coat, so that the two do not bear the same proportion to each other in the small arteries as in the larger. The disproportion, however, between them appears greater than it really is, some deception arising from the greater muscular power possessed by the smaller arteries, in consequence of which the inner coat will be more contracted, and therefore seem thicker. This circumstance alone makes the difference of thickness between the whole coats of a large artery and those of a small one appear less than it really is; accordingly we find the coats of the humeral artery in the horse apparently thicker than the coats of the axillary, the coats of the radial as thick as those of the humeral, and the artery near the hoof as thick in ils coats as any of the others. There is yet another circumstance which also deserves attention in comparing the two coats, namely, that in many places, but especially at the surfaces of contact in the elastic and muscular substances of the middle-sized arteries, the fibres of the muscular and elastic are very much blended or intermixed. I mention this, because otherwise we might be led to draw false conclusions with regard to the comparative quantity of each substance, and because

differ from true muscular fibre in possessing greater elasticity and hardness, and from being closer, firmer, more compact, and more brittle than muscles. They are also drier and flatter than the true muscular fibre, and contain no cellular tissue in their interstices. Honce some anatomists have been led to class this as a particular tissue (tissue jaune ou elastique) which enters into the composition of the air-passages, excretory ducts, intervertebral substances, coverings of the corpora cavernosa, &c, although it must be quite clear, from the preceding observations of the author, that it possesses a truly contractile as well as an elastic power. The decision of this question will probably depend on the idea which we affix to the term muscle; for if we limit the definition of this structure to such substances as possess a fibrous appearance, a peculiar chemical composition, and a power of alternate contraction and relaxation, I know not how we shall substantiate the affirmative of the question. The arteries, it is true, are fibrous, like many other dissimilar structures, but the appearance of these fibres is wholly different from that of muscles ; upon chemical analysis they are not found to contain fibrin, and when subjected to stimuli of different kinds they behave in a manner totally different from that of muscles, their contraction being continuous and permanent, and resembling much more that of the skin and excretory ducts than that of true muscular structure.] OF THE VASCULAR SYSTEM. 161 it explains by what means both these coats are made elastic. The external coat, however, is more so than the internal, being composed almost entirely of elastic substance, while the internal has a mixture of muscular with its elastic fibres. As there is, therefore, a difference in the elastic power of the.two coats, there must be a difference in their powers of contraction after death, the external coat, for instance, contracting more than the internal, and also, as there is a difference between the muscular and elastic powers of contraction, the muscular having the greatest, there must be a difference between the contracting powers of these two coats during life, but the reverse of that which takes place after death. • In those arteries which are evidently composed of two distinct substances, especially the smaller, we may observe two very opposite appearances, according as the elastic or muscular coats have contracted most. In the one, when we make a transverse section, and look upon the cut end, we may observe that the inner surfa.ce has been thrown into rugae, so as to fill up the whole cavity ; and if such an artery be slit up longitudinally, so as to expose its-inner surface, we shall find that inner surface forming wrinkles, which are principally longitudinal. If the finger is passed over that surface, it feels hard, while the external is soft; but if the artery be stretched, and allowed to recover itself by its elasticity, w-hich is the only power it now. has, it. will be felt equally soft on both surfaces, and its coats will be found to have become thinner than before.* On the contrary, I have observed in many of the smaller arteries, when the muscular contraction has been considerable, the external or elastic coat to be thrown into longitudinal inequalities, from not having an equal power of contraction with the muscular ; an artery under such circumstances being to the touch as hard as a cord. But if the muscular contraction be destroyed by stretching, or passing something through the artery, then it becomes very soft and pliant, and the muscular coat having once been stretched, without having the power of contracting again, is thrown into irregularities by the action of the elastic. The elastic coat of an artery is fibrous, and the direction of its fibres is principally transverse or circular; but where a branch is going off, or at the division of an artery into two, the direction of the fibres is very irregular. I cannot say that I have found any fibres which are to a great degree oblique or longitudinal, a circumstance that shows their simple elasticity to be equal to the intention or use, a transverse or circular direction of fibres not being the most advantageous for producing the greatest effect.t They are

* [The internal surface is thrown into rugae in consequence of the elasticity of the external coat being greater than the muscularity of the internal coat. How then can stretching smooth these rugae, when it ought rather to increase them ?] f This is a principle in mechanics 60 well known that it need not here be explained : we find it happily introduced in the disposition of muscles in various parts of the body. 162 HUNTER ON THE BLOOD. also elastic laterally [longitudinally?] from the direction of their fibres, which property shortens the artery when elongated by the blood, and I believe the muscles have little share in this action ; the whole of which tends to show that the elastic power is equal to the ask of producing, and really does produce, the natural state of the artery. What the direction of the muscular fibres may be I never could discover, but should suppose them oblique, because the degree of contraction appears greater than a straight muscle could produce, in which light a circular muscle is to be considered, as its effects are in the direction of its fibres ; for either the diameter or the circumference of the artery will decrease in the same proportion, but not the area, which will decrease in proportion to the square of the diameter. We should naturally suppose that, where the action of the heart is strong, elasticity is the' best property to sustain its force; and that where the force and elasticity are well proportioned, no mischief can ensue. Where the force, therefore, of the heart is greatest there is the greatest degree of elasticity, which yields with reluctance, and constantly endeavours to oppose and counteract that force. From these active powers of an artery, together with a foreign power, viz., the blood, acting upon them and distending their parietes, in a manner somewhat similar to the common action of fluids in canals, we may perceive that there are three actions which take place, all of which operate in concert with each other, and produce one ultimate effect. As the filling of the cavity of an artery produces an extension of its coats in every direction, the arteries are endowed with the elastic power, which, by contracting in all directions, brings them back again to their natural state. The action of the muscular power, being principally in a transverse direction, tends, when the artery is extended, to lessen its diameter, and assist the elastic power; but as its quantity of contraction is superior to that of the elastic power, it does or may contract the artery beyond what the latter could.effect. When the muscular action ceases, elasticity will be exerted to dilate the vessel and restore it to a middle state again, becoming the elongator or antagonist of the muscular coat, and by that means fitting it for a new action as described in other parts of the body. This will be most evident in the middle-sized vessels; for in the smaller, the proportion of elastic substance is not so considerable, and therefore it will contribute less to the dilatation of the vessel when the muscular coat relaxes. Yet we must suppose that no vessel even to its very extremity, is ever entirely collapsed; but that it possesses an elastic power sufficient to give it a middle state. Although these different structures do not always bear the same proportion to each other in arteries of the same size, yet we must conclude there is in these vessels a certain regular proportion preserved, and I am inclined to believe that the elasticity is in some degree in an inverse OF THE VASCULAR SYSTEM. 163 proportion to the decrease of size, presuming at the same time that the muscular power increases in the same proportion. A vessel is stretched beyond its natural state, first by the force of the heart, and in succession by the first order of vessels; then it is that the elastic power is exerted to contract the vessel, and restore it to the natural size ; and in the performance of this it will be more or less assisted by the muscular power, according to the size of the vessels; least in the larger, and most in the smaller vessels, as was observed above. There appears to be no muscular power capable of contracting an artery in its length, the whole of that contraction being produced by the elasticity. For in ' a transverse section of an artery, made when the muscles of the vessels are in a contracted state, it may always be observed, that the external or elastic coat immediately contracts longitudinally, and leaves the internal or muscular coat projecting; which would not be the case if there was a longitudinal muscular contraction equal to the elastic, and were not the quantity of muscular contraction greater than the elastic there would be no occasion for muscles. Another proof of this is, that if a piece of contracted artery be stretched transversely, or have its area increased, and be allowed to recover itself, it loses a part of its length. To understand this it will be necessary to know that muscular fibres by contraction become thicker, and in proportion corresponding with the degree of contraction in the muscle. The thickening in the muscle of a horse was found to be an increase of one-fourth part of thickness to one-third of a contraction;* from which it follows that the more the muscular fibre's of any vessel contract, the more the vessel is lengthened ; but destroy the muscular contraction by dilating the artery, and the elastic power, which acts in all directions, will immediately take place, andrestore the vessel to its proper size; which is a proof that the effect of the lateral swell produced by the muscular contraction is greater than that of the longitudinal elasticity of the artery. If we examine how much the vessel has lost of its length in this trial, we shall find it will amount to about one twelfth of the whole; a proof that the internal coat does not contract so much longitudinally by its muscular power as the external does by its elasticity. By multiplying such experiments we have further proofs that the power of muscular contraction acts chiefly in a circular direction;- for in a longitudinal section of an artery in its contracted state, the

* This calculation is not accurate; for in the experiments made to discover if the muscle lost of its size in the whole when contracted, I found it hardTy did : therefore, what it lost in length it must have acquired in thickness.* a [The fact that muscles, when they contract, acquire in thickness exactly what they lose in length, may easily be proved by observing the effect which the contraction of the ventricles of the heart, or live eels, have on a vessel of water, to which has previously been affixed a narrow graduated tub*?. We cannot, however, infer from this fact that the arteries are muscular, since precisely the same effect would follow from the contraction of any purely elastic body as follows from the contraction of a muscle.] 164 HUNTER ON THE BLOOD. internal coat does not project as in a transverse section, both coats remaining equal; or rather, indeed, the elastic coat projects beyond the other, from the internal muscular coat having contracted most. But if this section be stretched transversely, the external coat then contracts, and leaves the internal most projecting; because the internal or muscular has now no power of contraction. If the transverse extension be repeated, and to a greater degree, the artery, when allowed to recover itself, will have its inside turned outwards, as well as bent longitudinally, having the inside of the artery on the outside of the curve, and often bringing the two ends together: but this is easily accounted for; for as by the transverse extension of the artery its muscular contraction is destroyed, it becomes pliant; and the only resistance to the elastic power on this side being now removed, it is allowed to exert itself to its utmost extent. In doing this it bends the section in a longitudinal direction, which also inclines us to believe that the external part of the elastic coat is the most elastic. These experiments not only prove that the muscular power of an artery acts chiefly in a transverse direction, but also that the elastic power exists almost entirely in the external coat, and therefore that the internal coat must be the seat of the muscular power. Experiments on the arteries of a horse bled to death.-^-To ascertain the muscular power of contraction in the arteries, and determine the proportions which it bears to their elasticity, I made the following experiments upon the aorta, iliac, axillary, carotid, crural, humeral, and radial arteries of a horse. In this animal the muscles were all allowed to contract equally, and therefore we might reasonably presume that the vessels (at least such of them as were furnished with muscles) would also be contracted, the stimulus of death acting equally upon muscles in every form and every situation. The animal had also been bled to death, so that the vessels had an additional stimulus to produce contraction in them, as we know that all vessels in animals endeavour as much as possible to adapt themselves to the quantity of fluid circulating through them. As I supposed the larger arteries had less of this power than the smaller, and that perhaps in an inverse proportion to their size, in order to ascertain that fact, and also to contrast the two powers, I ■ made my first experiments upon the aorta and its nearest branches, continuing them on the other branches as these became smaller and smaller. The arteries were taken out of the. body with great care, so as not in the least to alter their texture or state of contraction. The experiments were made in the following manner: I took short sections of the different arteries, slit them up in a longitudinal direction, and in that state measured the breadth of each, by which means, as I conceived, I could ascertain their muscular contraction ; then taking the same sections, and stretching them transversely, I measured them in that state, which gave me the greatest elongation their muscular and elastic powers were capable of. As by this extension I had entirely destroyed their muscular contrac- OF THE VASCULAR SYSTEM. 165 tion, whatever degree of contraction they exerted afterwards must, I believe, have been owing to elasticity. Having allowed them to contract, I again measured them a third time in that state, and thus ascertained three different states of vessels, between which I could compare the difference either in the same or different sections, so as from the result to deduce with some degree of certainty the extent of these powers in every size of vessel. I say only with some degree of certainty; for I do not pretend to affirm that these experiments will always be exact; circumstances often happening in the body which prevent the stimulus of death from taking place with equal effect in every part. I have accordingly seen in the same artery some parts wider than others, even when the more contracted parts were nearest the heart, and this merely from the difference of action in the muscular power; for when that was destroyed by stretching, the parts contracted equally in both. Exp. 1. A circular section of the aorta ascendens, when slit up and opened into a plane, measured 5h inches transversely; on being stretched, it lengthened to 10^ ; the stretching power being removed, it contracted again to six inches, which we must suppose to be the middle state of the vessel. Hence the vessel appeared to have gained by stretching h an inch in width or rather circumference, which may be attributed to the relaxation of its muscular fibres, whose contraction must have been equal to xV; 6 inches being the natural size, or most contracted state of the elastic power. Exp. 2. A circular section of the aorta at the origin of the first intercostal artery, measuring 4£ inches, extended by stretching to 7J inches; it contracted again to 4 inches, and therefore gained tV. Exp. 3. A circular section of the aorta at the lower part of the thorax, on being stretched, and being allowed to contract again, gained TV. Exp. 4. A circular section of the iliac artery, measuring 2 inches, when stretched and allowed to contract again, measured 2V2 inches, and therefore gained £• Exp. 5. A circular section of the axillary artery, measuring 1 inch, when stretched and contracted again, measured 1| inch, therefore gained g. Exp. 6. A circular section of the carotid artery, measuring x^of an inch, when stretched, measured j£ and one half; and when contracted again, Tf; therefore had gained 2. Exp. 7. A circular section of the crural artery, measuring If, when contracted after being stretched, measured 1T22 inch, therefore gained \. Exp. 8. The humeral artery, near the joint of the elbow, in a contracted state, was thicker in its coats than the axillary; the circumference of the artery in that state being ■& and one half; after being stretched and contracted again, it measured t%» therefore gained \ and one half. Exp. 9. A circular section of the radial artery being taken, was 15 166 HUNTER ON THE BLOOD. found so contracted as hardly to be at all pervious ; and the coats, especially the inner, much thicker than even the humeral: when slit up it scarcely measured j\ of an inch; and when stretched and allowed to contract again, T62; it therefore gained r\, which was about the whole contraction of the artery. To see how far this power of recovery in the same artery took place at different distances from the source of the circulation, I made the following experiments on the spermatic artery of a bull, and likewise on the artery of the fore leg and penis. The spermatic artery, near the aorta, when stretched longitudinally, recovered perfectly the former length; when stretched transversely it likewise recovered perfectly. About the middle, when stretched transversely, it gained TV. Upon the testicle when stretched transversely, it gained i, which was its muscular power. The humeral portion of the artery of the fore leg, when stretched transversely, and also longitudinally, recovered entirely. The artery of one hoof, or rather finger, when stretched transversely, gained ^,which was the muscular power: when stretched longitudinally it recovered perfectly. The artery of the penis, when stretched longitudinally or transversely, recovered itself perfectly. This artery is considerably more elastic longitudinally than the others, but not so transversely. This increased elasticity in the longitudinal direction may be intended to allow of the difference in the length of the penis at different times. From these experiments we see that the power of recovery in a vessel is greater in proportion as it is nearer to the heart; but as it becomes more distant it lessens, which shows the decrease of the elastic and the increase of the muscular power.

* [It may be proper to observe that the proportional rates of contraction by death, as set down in the above table, are deduced from the contracted instead of from the natural or middle state of the vessels; independently of which the numbers themselves are not correctly deduced. The following fractions represent the respective degrees of contraction in each case (omitting the 3d, for which there are no data), calculated for the natural state of the vessel, viz., J _1 112211 T2> iT» T> "?' T> T» tf' 2' OF THE VASCULAR SYSTEM. 167 Experiments on the power of Arteries to contract longitudinally.

To prove that arteries do not produce the same power of muscular contraction in a longitudinal which they do in a transverse direction, the following experiments were made. Exp. 1. A longitudinal section of the aorta ascendens, measuring two inches, when stretched and allowed again to contract measured the same length. Exp. 2. A longitudinal section of the aorta descendens at the lower part of the thorax, of a given length, after having been stretched, contracted exactly the same length. Exp. 3. Two inches of the same carotid artery used in the sixth experiment, when stretched longitudinally, recovered itself, so as not to be longer than before the experiment. Exp. 4. A portion of that humeral artery used in the eighth of the former experiments was not altered in its original length, when it recovered itself after being stretched. These experiments appear to be decisive, and prove that the muscular power acts chiefly in a transverse direction; yet it is to be observed that the elastic power of arteries is greater in a longitudinal than in a transverse direction. This appears to be intended to counteract the lengthening effect of the heart, as well as that arising from the action of the muscular coat; for the transverse contraction of that coat lengthens the artery, and therefore stretches the elastic, which again contracts upon the diastole of the artery. From the account we have given of those substances which compose an artery, we may perceive it has two powers, the one elastic and the other muscular. We see also that the larger arteries are principally endowed with the elastic power, and the smaller with the muscular; that the elastic is always gradually diminishing in the smaller, and the muscular increasing, till, at last, probably, the action of an artery is almost wholly muscular; yet I think it is not to be supposed but that some degree of elasticity is continued to the extremity of an artery, for the middle state cannot be procured without it, and I conceive the middle state to be essential to every part of an artery. Let us now apply these two powers of action, or, to speak more properly, of reaction, with their different proportions in the different parts of the arterial system. From these different proportions we must suppose the elastic to be best fitted for sustaining a force applied to it, (such as the motion of the blood given by the heart,) and propelling it along the vessel; the muscular power, most probably, is required to assist in continuing that motion, the force of the heart being partly spent, but certainly was intended to dispose of the blood when arrived at its place of destination ; for elasticity can neither assist in the one nor the other, although it is still of use, through the whole, to preserve the middle state. Elasticity is better adapted to sustain a force than muscular power; for an elastic body recovers itself again, whenever the 168 HUNTER ON THE BLOOD. stretching cause suspends its action, while muscles endeavour to adapt themselves to circumstances as they arise. This is verified by different sorts of engines whose pipes are made of different metals. A pipe made of lead, for instance, will in time dilate and become useless ;* whereas a pipe of iron will react on the fluid, if the force of the fluid be in proportion to the elastic power of the iron; but the lead having little or no elasticity, whenever it is stretched it will remain so, and every new force will stretch it more and more. We are therefore to suppose that the force of the heart is not capable of streUching the artery so much as to detroy its elasticity : or, in other words, the force of the heart is not able to dilate the artery beyond the contracting power. As the motion of the blood is mechanical, elasticity is best adapted to take off the immediate force of the heart; and as we go from the heart this property becomes less necessary, because in this course the influence of the heart is gradually lessened, by which means a more equal motion of the blood is immediately produced, and even in the first artery a continued stream is at all times obtained, although it is considerably increased by each contraction of the heart. Without this power the motion of the blood in the aorta would have been similar to what it is in its passage out of the heart, and would have been nearly the same in every part of the arterial system. For though the motion of the blood out of the heart be by interrupted jerks, yet the whole arterial tube being more or less elastic, the motion of the blood becomes gradually more uniform from this cause. Elasticity in arteries acts like a pair of double bellows: although their motion be alternate, the stream of air is continued; and if it were to pass through a long elastic pipe, resembling an artery, the current of air would be still more uniform.f The advantage arising from elasticity in the arterial system will be more complete in the young subject than in the old: for in the latter, the elasticity of the arteries being very considerably diminished, more especially in the larger trunks, where the force of the heart requires to be broken, the blood will be thrown into the second and third order of vessels with increased velocity. In the young the current is slower, from the reaction of the elastic power during the relaxed state of the heart; whereas at the heart the motion is equal to the contraction of the heart; and as the heart is probably twice the time in relaxing that it is in contracting, from this cause alone we may suppose the whole is two-

* This accounts for the size of aneurisms in arteries whose coats must have lost their elasticity before they could be dilated. t [The application of this principle in the construction of water-pumps and fireengines is extremely simple. It consists in making the water pass through a chamber of condensed air, the elasticity of which causes the water to issue forth in a continued and uniform stream, instead of by jerks. This transformation of an alternating into a continued action may be expressed in the following proposition of mechanics. Every intermitting motion may be converted into a continued one, by employing the original force to compress a reservoir or spring, which keeps up a constant reaction.] OF THE VASCULAR SYSTEM. 169 thirds less in the smaller vessels. As elastic bodies have a middle state, or state of rest, to which they return after having been dilated or contracted by any other power, and as they must always be acted upon before they can react, the use of elasticity in the arterial system will be very evident. It is by this means that the vessels adapt themselves to the different motions of the body, as flexion and extension; so that one side of an artery contracts while the other is elongated, and the canal is always open for the reception of blood in the curved, stretched, or relaxed state. The muscular power of an artery renders a smaller force of the heart sufficient for the purposes of circulation; for the heart need only to act with such force as will be sufficient to carry the blood through the larger arteries, and then the muscular power of the arteries takes it up, and, as it were, removes the load of blood while the heart is dilating. In confirmation of this remark, it is observable in animals whose arteries are very muscular, that the heart is proportionably weaker, so that the muscular portion of the vessels becomes a second part to the heart, acting where the power of the heart begins to fail, and increasing in strength as that decreases in power. Besides this, it disposes of such part of the blood as is necessary for the animal ceconomy, principally in growth, repair, and secretions. At the extreme ends of the arteries, therefore, we must suppose that their actions are varied from that of simply conveying blood, except those arteries which are continued into veins.

§ 4. Of the Vasa Arteriarum. The arteries are furnished with both arteries and veins, although it cannot be said that they are to appearance very vascular. Their arteries come from neighbouring vessels, and not from the artery itself which they supply. This we see in dissection ; and I found by filling an artery, such as the carotid, with fine injection, that still the arteries of the artery were not injected. On laying the coats of arteries bare in the living body, we can discern their vessels more evidently some little time after the exposure, for then they become vessels conveying red blood, as in a beginning inflammation, growing turgid, when the arteries may be easily discerned from the veins by the difference of colour of the blood in each: these observations will also generally apply to the corresponding veins. Perhaps arteries afford the most striking instance of animal substance furnished with two powers existing in the same part, one to resist mechanical impulse, the other to produce action. The first of these powers is greatest where there is the most impulse to resist ; therefore we find it particularly in the arteries nearest to the heart, the better to support the force of that organ : but in those parts where gravitation is gradually increasing, the diminution of power in the artery is not in proportion to the diminution of the force of the heart. 15* 170 HUNTER ON THE BLOOD. In the veins the allotment of strength is commonly the reverse, for as they have nothing mechanical to resist, but the effect of gravitation, their principal strength is at the extremities. We are to suppose that the power of the heart, and the mechanical strength of the arteries, bear a just proportion to each other; and therefore by ascertaining the last we may give a tolerable good guess with respect to the other. In this view, to determine the strength of the ventricles, so far as I was able, I made comparative trials of the strength of the aorta and pulmonary arteries of a healthy young man. I separated a circular section of each, and on being slit, they measured 3¥ inches, their breadths being also equal. On trial, I found the aorta, being stretched to near 5 inches, broke with a weight of eight pounds. The pulmonary artery stretched to near 5i inches, and then broke with four pounds twelve ounces. This experiment I have repeated, but with very different results; for in one experiment, although the aorta took one pound ten ounces to stretch it, while the pulmonary artery took only six ounces, yet to break this pulmonary artery required eleven pounds three ounces, while the aorta broke with ten pounds four ounces; but this difference I impute to the aorta having lost its elasticity, which is very apt to happen in that vessel. There is nearly the same proportion of elasticity in both arteries; but the strength of the aorta in the first experiment appeared to be nearly double that of the pulmonary artery, while in the second it was less ; yet we must suppose the result of the first experiment nearer the truth, for we seldom find the pulmonary artery diseased, while the aorta is seldom otherwise. The mechanical strength of arteries is much greater in the trunk than in the branches, which is-evident from accidents and from injections in dead bodies ; for when we inject arteries with too much force, the first extravasation takes place in the smaller vessels. This can only be proved by subtle injections, which do not become solid by cold, such injections keeping up an equal pressure throughout the arterial system. In such cases the smaller arteries are found to give way first, viz., those of the muscles, pia mater, and the cellular membrane; which contradicts Haller's theory of the relative strength of the coats of the vessels. I am however inclined to suppose that they are even weaker in proportion to their size, viz., in proportion to the diminished force of the heart, or motion of the blood ; but how far this is the case I will not venture to determine, as mechanical strength is not so much wanted in the smaller arteries as muscular; and as the mechanical strength of muscles appears to be less than the power oi their own contraction, experiments made on the dead body upon parts whose uses arise from an action within themselves when active, are not conclusive. The flexor policis longus, being one of the most detached muscles in the body respecting structure and use, has been selected for experiments on this subject, and is found OF THE VASCULAR SYSTEM. 171 to raise by its action a greater weight than it can sustain after death. This, however, is liable to fallacy, as the two experiments are made on different muscles, one certainly healthy, the other most probably weakened by the disease preceding death. The coats of arteries are not equally strong on all sides of the same artery; at the bending of a joint they are strongest on the convex side through the whole length of the curve; this is most evident in the permanent curves, such as in the great curvature of the aorta. Arteries are likewise strongest at the sharp angles made by a trunk and its branch, and at the angle formed by a trunk divided into two. These parts have the blood, as it were, dashing against them. Those likewise are the parts which first lose their elasticity and soonest ossify, being generally more stretched than the other parts of an artery, and making a kind of bag. These circumstances are chiefly observable in the curvature of the aorta and of the internal carotids, and at the division of the aorta into the two iliacs.

The heart is an organ which is the great agent in the motion of the blood; but it is not essential to animals of every class, nor for the motion of the blood in every part where it is perfect; it is less so than the nerves, and many even possess the organs of generation, that have no heart. Its actions in health are regular, and characteristic of that state; and in disease its actions are in some degree characteristic of the disease; but although there is that connexion between the body and the heart, yet there seems not to be such a connexion between the heart and the body,* for the heart may be in some degree disordered in its action, yet the body but little affected : it is therefore only to be considered as a local agent very little affecting the constitution sympathetically, except by means of the failure in its duty. The heart in the more perfect animals is double, answerable to the two circulations,—the one through the lungs, the other over the body; but many that have only single hearts, have what is analogous to a double circulation; and this is performed in very different ways in different animals, so that one of the circulations in these is performed without a heart. A large class of animals, well known and pretty perfect in their construction, namely, all the class offish, have no heart for the motion of the blood in the great circulation, or that over the whole body, having only a heart for the lungs or branchiae, while the snail has only a heart for the great circulation, and none for the lungs: in the liver also of the most perfect animals, the motion of the blood in the vena portae and vena cava hepatica is carried on without a heart. The absorbing

* [I apprehend that a reversal of the terms of this proposition is required, in order that the sense may agree with the context.] 172 HUNTER ON THE BLOOD. system in every animal has no immediate propelling power ; therefore this propelling power is not universally necessary. The heart varies in its structure in different orders of animals, principally with respect to the number of cavities and their communications with each other, yet in all nearly the same purpose is answered. I shall here observe, that in the bird and quadruped there is a double circulation, which requires a double heart, namely, a heart for each circulation, each heart consisting of an auricle and ventricle, called the right and the left; and from their forming but one body among them, they are all included in one heart; the right side, or heart, may be called the pulmonary, and the left may be called the corporeal. In many classes of animals there is to be found only one of these hearts ; and according to the class, it is either the pulmonary or corporeal. In the fish, as was observed, the heart is the pulmonary ; and in the snail the heart is the corporeal; so that the corporeal motion of the blood in the fish is carried on without a heart; and in the snail the pulmonary motion is carried on without a heart. In the winged insects, which have but one heart, as also but one circulation, there is this heart, answering both purposes; and in all these varieties breathing is the principal object. The heart in most animals is composed principally of a strong muscle, thrown into the form of a cavity or cavities; but it is not wholly muscular, being in part tendinous or ligamentous, which last parts have neither action nor reaction within themselves,, but are only acted upon ; they are therefore made inelastic and rigid, to support the force of the acting parts in this action without varying in themselves. In all animals which have red blood the heart is the reddest muscle in the body. Thus, in the bird, whose muscles are mostly white, the heart is red: we find it the same in the white fish. As it differs in the different orders of animals respecting the number of cavities, it may admit of dispute what are to be reckoned truly hearts, and what only appendages ; for some of its cavities may only be considered as reservoirs peculiar to some hearts. The most simple form of heart is composed of one cavity only, and the most complicated has no more than two ; it would seem indeed to increase progressively in the number of cavities from one to four, which includes the mixed ; yet two of these ought not to be called parts of the heart, although they belong to it. The single cavity of the heart in the most simple class, or the two in the most complicated, are called ventricles. The other cavities belonging to it are called auricles. Many of those which have one ventricle only, have no auricle, such as insects; but there are others which have both a ventricle and auricle, such as fish, the snail, and many shell-fish; some of the last class have indeed two auricles, with only one ventricle, which shows that the number of auricles is not fixed under the same mode of circulation. Those animals which OF THE VASCULAR SYSTEM. 173 have two distinct ventricles, constituting four cavities, are what are called quadrupeds or mammalia, and birds. If the auricles are considered as parts of the heart, we might class animals which have hearts according to the number of their cavities, viz., monocoilia, dicoilia, tricoilia, tetracoilia ; the tricoilia is a mixture of the dicoilia and tetracoilia. This is the case in distinct classes of animals; but it also takes place in other classes at different stages of life, for the foetus of the class possessing four cavities may be classed with the mixed, having but one auricle, in consequence of the communication which exists in the foetus between the two; and also but one ventricle, by means of the union which exists between the two arteries, which produces an union of blood, although not in the same way. Those passages, however, are shut up almost immediately after birth, or at least the canalis arteriosus,* which immediately prevents the foramen ovale from producing its former effects; therefore it is not so necessary it should be shut up in the adult. I have seen it, to common appearance, as much open as in a foetus. The heart may be considered as a truly mechanical engine ; for although muscles are the powers in an animal, yet these powers are themselves often converted into a machine, of which the heart is a strong instance ; for from the disposition of its muscular fibres, tendons, ligaments, and valves, it is adapted to mechanical purposes ; and this construction makes it a complete organ or machine in itself. It is most probable that by means of this viscus a quicker supply of blood is furnished than otherwise could be effected. In birds and quadrupeds, the heart, by its action, first throws out the blood, both that which is fit for the purposes of life, and that which requires to be prepared, the last having lost those salutary powers in the growth, repairs, secretion, etc., in the machine. It may be said to give the first impulse to the blood, producing a greater velocity where the blood is simply conveyed to the parts for whose use it is destined. This velocity is alternately greater and less, and from the construction of the arteries alone, is gradually diminished, becoming more uniform where slowness and evenness of motion is necessary. This velocity of the blood in those parts where it is to be considered as passing only, allows a much larger quantity to flow through the part to which it is destined than otherwise could be transmitted. The heart is placed in the vascular system, to be ready to receive the blood from the body, and to propel it back on the body again, although not in the centre of the whole; but it is reasonable to suppose that its situation is such as to be best suited to the various parts of the body; some parts requiring a brisk, others a more languid circulation. Some also require a greater supply of blood than others. We may suppose thai the parts near the heart will receive more blood that those at a greater distance, because

* There have been instances of the canalis arteriosus being open in the adult. 174 HUNTER ON THE BLOOD. the resistance will be less if the vessels are of equal size in proportion to the size of the part. . The situation of the heart in the body varies in different animals. One would imagine when the animal was divided into its several portions, appropriated for the different purposes, that the situation of the heart would be nearly the same in all; but we find this not to be the case; its situation depends upon the organs of respiration more than any other part. It is placed in what is called the chest in the quadruped, bird, amphibia, fish, and in the aquatic and terrestrial insect: but not in what may be called the chest in the flying insect. The chest in the aquatic insect seems best suited to contain the lungs and branchiae, and therefore the heart is placed there; but as the lungs of the flying insect are placed through the whole body, the heart is more diffused, extending through the whole length of the animal. The situation, therefore, of the heart is chiefly connected with that of the lungs ; and when it is united with the body at large, it is because the lungs are also so disposed. We must suppose that these two have a relation to each other. A heart is composed of an auricle and ventricle, and it is the ventricle which sends the blood through its course in the circulation; so that, from what has been said, it must appear that the ventricle is the true heart, the other parts having only secondary uses. As the ventricle is the part which propels the blood to the different parts of the body, its muscular power must be adequate to that purpose, and therefore it has a very strong muscular coat. Much more pains than were necessary have been taken to dissect and describe the course and arrangement of the muscular fibres of the heart, as if the knowledge of the course of its fibres could in the least account for its action. But as the heart can, in its contracted state, almost throw out its whole contents, to produce this effect its fibres must pass obliquely. Its red colour arises probably from its being at the fountain head of the circulation, for those animals that have but little red blood, have it only in those parts near the heart; and the heart being nearest to its own powers, receives the blood before the vessels can so act as to dispose of the red blood, or allow of a kind of separation by distance: its constant action, too, renders it more red, as happens in other muscles. The ventricles in the quadruped, bird, and amphibia, are called right and left, and this accords very well with the situation in such animals; but where there is only one ventricle, and that in some acting the part of the right, as in fish, and in others acting the part of the left as in the snail, we ought to have some term expressive of their immediate use, and such as would apply to all animals that have such a viscus.* The auricles of the heart are to be considered only as reservoirs

* [The epithets pulmonary and systematic sufficiently express thia difference of function.] OF THE VASCULAR SYSTEM. 175 for the blood, to be ready to supply the ventricles ; for an auricle is not to be found in all the animals which have a ventricle; nor does the number of auricles always correspond to that of the ventricles. Where the veins entering into the heart are small, in comparison to the quantity of blood which is wanted in the ventricles, there we have an auricle; but where the veins near to the heart are large, there is no auricle, as in the lobster, and generally in insects. In the snail, where the veins in common are large, yet as they are small where they enter the heart, there is an auricle ; and as its office is somewhat similar to a large vein, it has some of its properties, viz., being in some degree both elastic and muscular. The name sinus venosus is a very proper one, and as a proof that it is only such in the circulation, there are no valves placed between it and the veins.* As the heart is an engine formed to keep up the motion of the blood, and as it is necessary that this motion should be determined in a particular direction, it is adapted, as are also the other parts of the vascular system, to this purpose. The heart is formed into a cavity, through which the blood must pass, receiving at once a considerable quantity of this fluid, upon which it immediately acts with equal force, although not progressively, as an intestine: and that this motion of the blood may be regulated, and a retrograde motion prevented, we find the valves constructed. A valve, I believe, is in general understood to be a part in every machine calculated to allow whatever is to pass to move in one direction only, and the valves in the vascular system are intended for this purpose. They are of two kinds, having two modes of attachment, which is suited to the action of the part to which they are attached, and making a very essential difference in their forma-

* [In fish, as well as in several other animals, there are commonly placed two crescentic-shaped valves at the entrance into the auricle, between it and the sinus venosus, or bulbous enlargement of the vense cava?, which fact the author must have been well acquainted with, as several preparations are set up in the Hunterian Museum illustrative of this point. The observation, however, of the author in other respects is perfectly correct, and might be illustrated by numerous examples from comparative anatomy. Thus, in most of the batrachian animals the auricles are remarkable for their large size and the weakness of their parietes, which unite to give them an appearance much more resembling a great venous sinus than a true auricle. This conformation is particularly conspicuous in the Siren lacertina, where the number of fimbriated follicular processes sent off from the auricle give it the appearance of the branchial divisions of the vena cava in the cephalopoda. In the gallery, or physiological department of the museum (Nos. 873-974), there are numerous examples of these superadded sinuses, together with every variety of cardiac construction. In the chameleon the auricles are provided with two very large venous receptacles, twice as large as the auricles themselves, and extending the whole length of the chest; the object of which plainly is, to provide a receptacle for the superfluous blood when the tongue, which is a large erectile organ, and the only one assigned to this animal for the prehension of its prey, is not in action. (See Houston in Trs. of R. I. Acad., xvi. 177.) Indeed this species of construction seems to be connected with the varying conditions of the circulation in most of those animals in which it occurs, whose habits of eating, diving, breathing, or exerting themselves, are generally extremely irregular.] 176 HUNTER ON THE BLOOD. tion. They are thin, inelastic membranes, having no action within themselves, with one edge fixed, the other loose in some, but not entirely so in others ; they are either attached in a circular form, or in an oblique one. The circular attachment belongs to those of the ventricles, and the oblique to those of the arteries and veins. The circular are the most complex, requiring an additional apparatus to make them answer the intended purpose; for it is necessary that their loose, floating edges should be retained from inverting themselves into the auricle upon the contraction of the ventricles. This is done by tendons, which are fixed at one extremity along the edge of the valves, and at the other to some part upon the inside of the ventricle. The tendons which are longest are inserted into columns of muscle, the intention of which is very evident: for if they had gone the whole length in form of a tendon, they would have been too long when the heart contracted, and the valves in such a case would have allowed of being pushed into the auricles, so far as to admit of the blood escaping back again into the cavity; but the carneee columnm keep the valves within the ventricle, in the contracted state of the ventricles; and the dilatation of the ventricles counteracts them, and places the valves in their proper situation in that state. If the valves in this cavity had been placed obliquely along the inner sides of the ventricle, as in the beginning of the arteries and in the veins, the attachment then would not have been permanent; for it would have varied according to the relaxed or contracted state of the heart: it would have been short in the contracted state, and longer in the relaxed; therefore, to have a fixed base, it was necessary for them to be attached all round the mouth of the ventricles. I have reason to believe that the valves on the right side of the heart do not so perfectly do their duty as those of the left, therefore wTe may suppose it was not so necessary. The vessels of the heart are called coronary arteries and veins. In quadrupeds and birds there are two coronary arteries, which arise from the aorta just at its beginning, behind two of the valves of the artery. From this circumstance a theory respecting the action of the heart was raised ; but in the amphibia they arise at some distance, and not always from the same artery in the same species, often from the subclavian, and often from the anterior surface of the ascending aorta, which is reflected back. In the fish they arise from the artery as they are coming from the gills. The veins pass into the right auricle. In all animals which have an auricle and ventricle, so far as I know, there is a bag (unattached) in which they are placed, called a pericardium ;* but the insect tribe, whether aerial, aquatic, or

* There have been instances where the pericardium has been wanting in the human subject: a case of this kind is published by Dr. Baillie, in a periodical work entitled " Transactions of a Society instituted for promoting Medical and Chirurgical Knowledge." OF THE VASCULAR SYSTEM. 177 terrestrial, have none, their heart being attached to the surrounding parts by the cellular membrane, or some other mode of attachment. In those animals which have this bag it is not a smooth termination of the cellular membrane, as the peritonasum may be supposed to be, but a distinct bag, as in man and all quadrupeds. The use of this bag is probably that the heart may move with more ease and facility ; trie two parts, to wit, the contained and containing, acting as a kind of joint with a capsular ligament, and like such joints it contains a fluid, but not a synovia, as the two surfaces are not hard like cartilage; besides, the heart is kept very much in its place, which we must suppose is of use. I have conceived it also to be possible, as it is a pretty strong membrane, that it might in some degree preserve the heart from too great distension ; for I have observed, by injections, that a little force will distend it beyond its natural size, if a part of the pericardium be taken off; but in the heart mentioned by Dr. Baillie there was no particular increase of bulk. This bag, like most others, has a fluid which moistens the two surfaces. In every other cavity of the body the fluid is no more in quantity than what is simply sufficient to moisten the parts. In this bag, however, it is more, from whence it has acquired the name of liquor pericardii. There may be about a tea-spoonful in the whole. This fluid appears to be serum, and is commonly a little tinged with blood, which arises from the transudation of the red blood after death. That this cavity has more water in it than most other cavities of the body, may arise from there being a greater action of those parts on one another than takes place in others ; it may also fill up the interstices formed between two round bodies, so that when the pulmonary artery and aorta are filled they may more easily assume a round figure. The size of a heart we should naturally suppose is proportioned to the size of the animal and the natural quantity of blood, which last is, we might conceive, ever in proportion to the size of the animal; but I believe these modes of calculation will not be found to be just, for certainly some animals have much more blood in proportion to their size than others; and I believe the heart is not in size proportioned to the size of the animal, but bears a compound proportion or ratio to the quantity of blood to be moved and the frequency of the stroke it has to make; for when the quantity of blood is decreased, the frequency of the stroke must be increased; and as a proof of this we find when an animal loses a considerable quantity of blood, the heart increases in its frequency of stroke, as also in its violence. That it principally bears proportion to the quantity of blood is evident; for the right ventricle is equal in size to the left, if not larger, although it sends its blood to the lungs only, which are infinitely small when compared with the whole body; and the hearts of those animals which have but one ventricle, as fish, for instance, which is similar in use to our right, are 178 HUNTER ON THE BLOOD. perhaps made as large in proportion to the size of the body as both ventricles in the quadruped.* The strength of a heart is commonly, if not always, in proportion to the size of the parts to which the blood is carried and the velocity with which it is propelled; which becomes a collateral proof that it is a universal agent in the circulation. In the complete heart this is not equal" in every part of the same heart; the right ventricle being much weaker than the left, but still in the above proportions. The proportion between the two will be best known by ascertaining the difference in the strength of the two arteries, and this again will differ according to the whole parts the blood is sent to by the heart. In the fish, for instance, it is only necessary it should bear the proportion in strength to the whole fish that our right ventricle bears to our lungs, which is not in the least equal to that of the left ventricle; or, in other words, its strength should be commensurate with the size of the lungs. However, it is most probable that the right ventricle in the quadruped is stronger than in this proportion, because it is obliged to move a larger quantity of blood than is contained in any other part of the body of the same size, and with greater velocity : in the double heart, therefore, such as the human, the two cavities are not of equal strength, each being nearly in proportion to the size of the parts, or rather to the distance the blood is to go; the right ventricle only throwing it into the lungs, the left into the body. As a proof of this doctrine, we find that in the foetal state of this class of animals the two ventricles and the two large arteries are equal in strength. Indeed, from reasoning we should expect this, and even that the right ventricle should rather be the strongest, for at this period it sends the blood to the lower extremities; but since both the arteries unite into one canal, we must suppose it to be necessary that the velocities of the blood in both should be equal; and upon examination we find the two ventricles to be nearly equal in thickness in this young state of the animal. The mixed kind of heart, as that of the turtle, &c, is under the same predicament. The two ventricles are to be considered as joint agents in the circulation ; and as the pulmonary artery and aorta are equally strong, it becomes a proof that the strength of the heart must be equal everywhere. If we were to estimate the strength of the ventricles in those possessed of four cavities, by the strength of the aorta and pulmonary

* [The heart in animals of large dimensions is singularly small as compared with the bulk of the whole body, at the same time that its action is remarkably slow. In the foetus, on the contrary, the heart is proportionably large, and its action in the same degree rapid. It would appear from the investigations of Treviranus, that the size of the heart as compared with the whole body decreases in proportion as the animal descends in the zoological scale. The following were the respective weights of the heart in different animals: mammalia, fa to -^ ; birds, & to ,1^ ; amphibia, ^ to -^; fishes, ^v to ^. The rate of pulsation seems to diminish nearly in the same proportion as the size.] OF THE VASCULAR SYSTEM. 179 arteries, either by their absolute strength or elasticity, we might come pretty near the truth. Dr. Hales made an experiment on a horse to ascertain the strength of the arteries, which gives us the power of the left ventricle ; but all this explains nothing, for its power is equal to the use wanted. The power of contraction of the ventricle must be within the strength of the artery ; but it is hardly possible to ascertain what is the strength of an artery; nor, if we could, would it enable us to ascertain the strength of the ventricle, for the force of the heart is in part immediately lost by the blood being allowed to pass on, although not so freely as if the artery was open at the other end : in proportion, therefore, to the retardment, the artery is affected. We can ascertain the elastic power of a given section of an artery, and also its absolute strength ; but we are not acquainted with the size of a section that will give the strength of the artery to which it belonged when the whole was in a perfect state or form. Exp. 1. A section of a sound aorta, close to the valves, threequarters of an inch long, was stretched transversely to its greatest extent, which state was ascertained by measuring it with a pair of compasses, and the artery was allowed to contract. The weight required to stretch it again to the same degree was one pound ten ounces. To break the artery required ten pounds and a quarter. Exp. 2. A section of the pulmonary artery, similar to the former in length and situation, required six ounces two drachms to stretch it to its full extent. To break it required eleven pounds threequarters. The use of this viscus is in general very well known : however, its use has been frequently supposed to be more universal than it really is. It gives to the blood its motion in most animals, and in all it sends the blood to the organs of respiration: in the flying insect it sends the blood both to those organs and to the body at large; but in fish to those organs only, the body at large in them having no heart. In the amphibia there is an attempt towards a heart both for the lungs and body, but not two distinct hearts. In the bird and quadruped there is a distinct heart for each. We may say, therefore, that there is one heart for respiration and another for the life, nourishment, &c, of the animal: these constitute the two ventricles. As the extent of these two circulations is different, the two hearts, or, in other words, the two ventricles, are suited in their strength to the different extents of each circulation, as was observed above, in treating of the strength of the heart. How far the heart is alone capable of carrying on the circulation is not to be ascertained; for although the circulation is carried on in paralytic cases, yet this does not exclude the involuntary nervous influence of the part: this, however, varies very much in different classes of animals; for I have already observed, concerning the structure of the arteries, that their muscularity assisted in the circu 180 HUNTER ON THE BLOOD. lation, and that in proportion as the vessels in general were endowed with this power the heart was weaker. I believe that the quadruped has the strongest heart of any class of animals; and I believe that their vessels have the least muscular power, more especially near the heart. The immediate use of the heart in an animal would seem to be generally subject to as little variety as that of any other viscus; but perhaps "the heart is subject to more variety than any other part in its construction. 1 have observed that it is either single, double, or mixed; that it is single without an auricle, single with one auricle, single with two auricles, double with a union of the two, making the mixed, and double with two auricles. With respect to its use, it is, in the most simple kind of single heart, to propel the blood through the body, immediately from the veins; which blood is to receive its purification in this passage, when the lungs are disposed throughout the body, as in the flying insect. In another single heart it is intended to mix both the purified and the adulterated blood, and of course to throw it out to the body and lungs equally in this mixed state, as in the lobster. In the single heart, with an auricle, its use is, in one class, to throw the blood throughout the body, after being purified, as in the snail; and in another single kind, with an auricle, it is to receive the blood from the body, and send it to the lungs only, as in all fish. In the single heart with two auricles it is formed to receive the blood both purified and unpurified, and dispose of it to both body and lungs in that state, as was observed in the lobster: the same thing happens, in some degree, in the turtle, snake, foetus, etc. In the double heart with two auricles it acts like an union of the heart of the snail with that of the fish, one heart receiving the blood purified from the lungs, and sending it over the body, as in the snail; and the other receiving the blood from the body, and sending it into the lungs to be purified, as in the fish. From the above account we must see that the immediate use arising from the heart in one class of animals will not agree with its immediate use in another; but still, in all it is the engine employed to throw the blood to those parts into which the arteries conduct it.*

* [I have already noticed a remarkable instance of the reach of Hunter's genius in regard to the different phases which the higher orders of animals undergo in the process of their development, corresponding to the different types of inferior organization (see Prin.ofSur. p. 53, n.) Perhaps the most striking exemplification of this truth is to be found in the vascular system, the different conditions of which, presented by different classes of vertebrate animals, during the different periods of their development, represent each link of a continuous chain of developments, extending from the lowest animalcules up through the invertebrate genera, to fish, tadpoles, amphibia, and finally to man. As it would be impossible, however, in the brief compass of a note, to trace these various and highly curious transformations through all their stages, and the means by which they are effected, I beg leave to refer the curious reader to Prof. Carus's Comp. Anat, tr. by Mr. R. T. Gore; Prof! Grant's Lect. on Comp. Anat. (Lancet, 1833-4. vol. ii.); Rolando Sur la formation du Coeur et desviasseaux arteriels, veinpux ct capillaries (Journ. Compl. du Diet, des Sc. Med., xi. 323, xii. 34); Pander, Mem. sur le devel. du Poulet dans l'CEuf (ib. xiv. 306); Rusconi's different works on the larva of the salamander OF THE VASCULAR SVSTEM. 181 It is impossible to say what the quantity of blood is that is thrown out of the heart at each contraction. The size of a relaxed heart in the dead body of any animal gives us the size of the cavity, or what it is capable of holding; but muscles seldom or ever are obliged to relax themselves to their full extent in common actions, although they often are when extensive effects are to be produced. The heart, like every part constructed for action, has its times of action beyond, and also within, its natural limit of action ; but it is its natural action which should be ascertained. If we compare the actions of the heart with those of the body, we may suppose that the common quantity of motion in the heart is about half what it can perform; that is, it relaxes three-fourths, and contracts onehalf; therefore a ventricle which contains four ounces, will, in common, only dilate so as to contain three, and will only contract so as to throw out two. The question is, when the heart acts with more frequency, as from exercise, does it, or does it not also dilate and contract more fully, and also act with greater velocity in its contraction'? I believe that all these circumstances take place; for in exercise, the pulse not only becomes more frequent, but fuller, as if more was thrown out of the heart; and the heart is found to make a greater emotion in the chest, striking with its apex against the inside of the chest with greater force,* which can only arise from a greater quantity being thrown out, and with greater velocity. The breathing corresponds with the quantity of blood and the velocity, for if a larger quantity passes through the lungs in a given time, the breathing must be in the same proportion increased; if with a greater velocity, the same thing must necessarily take place; and if a greater quantity is thrown out, and with a greater velocity, then the arteries must relax in proportion, since the different parts must correspond with each other : we

and common frog; and also to the labours of Weber, Meckel, Martin St. Ange, and Cuvier. A brief description of these changes as they occur in man may be found in Meckel's Manuel oV'Anatomie, tr. by Jourdan and Breschet, i. 143.] * The reason why the apex of the heart strikes against the chest in its actions was, I believe, first accounted for by the late Dr. William Hunter, in his lectures, as far back as the year 1746. The systole and diastole of the heart simply, could not produce such an effect; nor could it have been produced if it had thrown the blood into a straight tube, in the direction of the axis of the left ventricle, as is the case with the ventricles of fish, and some other classes of animals; but by its throwing the blood into a curved tube, viz., the aorta, that artery at its curve endeavours to throw itself into a straight line to increase its capacity; but the aorta being the fixed point against the back, and the heart in some degree loose or pendulous, the influence of its own action is thrown upon itself, and it is tilted forwards against the inside of the chest.3 a [The above explanation is correct as far as it goes; but the cause assigned is not the only one why the heart strikes with its apex against the ribs at the moment of contraction. The direction of the mass of its fibres is also concerned which tends to tilt the apex forwards, as may clearly be proved by placino- the heart of any animal in a state of action on a plane surface, when it will be found that the apex moves forwards, although the base is comparatively stationary.] 16* 182 HUKTER ON THE BLOOD. must suppose, therefore, that in health, whenever there is any exertion greater than common, (which always increases the pulse), the heart dilates more, contracts more, and does both with greater velocity; this I conceive arises from a necessity, which begins first in the veins, for when the body is in action the blood in the veins is obliged to move with greater velocity than when at rest: how far there may be other reasons for this, 1 will not pretend to determine. Another question naturally arises : as we find that the times of repetition of the pulse or the action of the heart increase in many diseases, does the same thing happen, that is above supposed to arise, from exercise in health? viz., does the heart dilate more,contract more, and also contract with more velocity ? I believe this case does not in the least correspond with our former position. The pulse in such circumstances, although frequent, is small and hard, showing the arteries to be too much contracted by their muscular power, and therefore unfit to receive a large quantity of blood from the heart in any given time. The breathing does not correspond with the frequency of the pulsations; as in the former instance; yet it is possible that nearly the same quantity of blood may pass as when in health, the velocity in the contracted state of the heart and vessels making up for the increased size of the artery. That it moves faster in such state of vessels is, I think, probable; for in bleeding, the blood in the veins during such a state of vessels is commonly more florid.

Observations upon the heart's motion while under ihe influence of artificial breathing.

1. I observed that the auricles contracted but very little, so that they did not nearly empty themselves. 2. That the ventricles were not turgid at the time of their diastole, for I could feel them soft, and could easily compress them. 3. That the. ventricles became hard at the time of their systole. 4. That the heart, when it ceased to act, became nearly twice as large as when acting, and that it recovered its small size again whenever it began to act.*

* [I subjoin the following extract from my friend Dr. Hope's Treatise on Diseases of the Heart, p. 28, which places this subject in a clear point of view. The experiments from which the following conclusions were drawn were performed on an ass,and attested by competent witnesses: " Of the Motions of the Heart. 1. " The auricles contract so immediately before the ventricles, that the one motion is propagated into the other, almost as if by continuity of action; yet the motion is not so quick that it cannot readily be traced by the eye. 2. " The extent of the auricular contraction is very inconsiderable, probably not amounting to one-third of its volume. Hence the quantity of blood expelled by it into the ventricle is much less than its capacity would indicate. 3. " The ventricular contraction is the cause of the impulse against the side; first, because the auricular contraction is too inconsiderable to be capable of pro- OF THE VASCULAR SYSTEM. 183 Observations on the above appearances.—From the first observation, it would appear that the auricles are only reservoirs, capable of holding a much larger quantity than is necessary for filling the ventricles at any one time, in order that the ventricles may always have blood ready to fill them. From observation the

ducing it; secondly, because the impulse occurs after the auricular contraction, and simultaneously with the ventricular, as ascertained by the sight and touch; thirdly, because the impulse coincides with the pulse so accurately as not to admit of being ascribed to any but the same cause. 4. " It is the apex of the heart which strikes the ribs. 5. " The ventricular contraction commences suddenly ; but it is prolonged until an instant before the second sound, which instant is occupied by the ventricular diastole. 6. " The ventricles do not appear ever to empty themselves completely. 7. "The systole is followed by a diastole, which is an instantaneous motion, accompanied with an influx of blood from the auricles, by which the ventricles reexpand, but the apex collapses and retires from the side. 8. " After the diastole the ventricles remain quiescent, and in a state of apparently natural fulness, until again stimulated by the succeeding auricular contraction. " Of the Sounds* 9. "The first sound is caused by the systole of the ventricles. 10. " The second sound is occasioned by the diastole of the ventricles.

" Of the Rhythm. 11. " Order of succession: " 1. The auricular systole. " 2. The ventricular systole—pulse and impulse. " 3. The ventricular diastole. "4. The interval of ventricular repose, towards the termination of which the auricular systole takes place. " Duration. 12. " This is the same as indicated by Laennec, viz.: "The ventricular'systole occupies half the time, or thereabout, of a whole beat. " The ventricular diastole occupies one-fourth, or at most one-third. " The interval of repose occupies one-fourth, or rather less. " The auricular systole occupies a portion of the interval of repose." With regard to the double sound, which, it may be observed, is distinctly isochronous with the systole and diastole of the ventricles, various opinions have been entertained : nor indeed can the question be considered as perfectly decided at the present moment. Thus, the first sound has been variously ascribed to the rush of blood into the great arteries, to the closing of the auriculo-ventricular valves, to the muscular contraction of the heart, and to the collision of the particles of fluid in the ventricles. The second sound has also been ascribed to the reaction of the arterial columns of blood against the semilunar valves, thus suddenly tightening these bodies; and to the impulse of the blood from the auricles refilling the ventricles. (See Path, and Diag. of Diseases of the Chest, Zd edit. p. 163, by Dr. C. J. B. Williams; Mr. Turner in Med. Chir. Trs. of Edin., iii.; Dr. Corrigan in Trs. of King's and Queen's Coll. of Phys. of Ireland (New Series), i. 151 ; M. Magendie in Lancet, 1834-5, i.; and Mr. Carlile in Dubl. Journ. of Med. Sc, iv. 84.)] a The sound which is heard when the ear is applied to the region of the heart of a healthy person, is double, consisting of a dull slow sound, immediately followed by a short quick one. 184 HUNTER ON THE BLOOD. fourth, it would appear that any idea we form of the size of a heart, from those in dead bodies, must be far from the truth; for the blood coming from every part of the body to the heart, in some measure distends it while it is in a relaxed state, so that when the heart begins to contract (as muscles do some time after death), it is kept dilated by the contained blood.* However, it may be observed, that the increased size of the heart would be less in the present case, than natural, for the very quick motion of this viscus, under this irritation, hindered a full diastole; but when I left off blowing, and the heart ceased acting, it became large; and on resuming my artificial breathing, it again became small, which I did three times in the course of this experiment. But I think I have observed in general that the heart is not so much affected by the stimulus of death as the other muscles of the body. We seldom see a dead body that is not stiff; but we very often find the heart large and flabby, and not in the least contracted; and I am not certain but this may be the case also with some of the other vital parts, as the stomach and intestines. It is to be set down as a principle, that the action of every muscle is alternate contraction and relaxation ; and it cannot be otherwise; but as there is a necessity for a more constant and regular motion in the heart than probably in any of the other muscles, more disputes have arisen about the cause of its regular alternate motion. Some have accounted for it from the position of the mouths of the coronary arteries respecting the valves of the arota, supposing, erroneously, that the heart has its blood in the time of its relaxation ;f but the circulation, whether existing or not, has not such immediate effect upon a muscle; nor would it account for the action of the auricle in the same animal, nor for the action of the heart in a fish ; but from what we shall observe on the valves of the aorta, we shall find that this opinion immediately falls to the ground. An easy experiment may put this beyond a doubt; for if the heart of a dog be laid open, and the coronary artery wounded, it will be found to jet out its blood as the aorta distends. Others have accounted for the alternate motion of the heart, from the course of its nerves passing between the two great arteries, so as to be compressed when the arteries are dilated; but this could only produce relaxation. We know, too, that such immediate compression on a nerve has no such immediate effect upon a muscle, not to say that it would most probably make it contract; for when the nerves of the

*" * [This observation applies particularly to the right or pulmonic side of the heart, which was hence incorrectly concluded by Haller to be f ths more capacious than the left. The left cavities are generally found nearly empty after death; but during life it is probable that both ventricles have the same capacity. It is certain that they project the same quantity of blood in a given time, and therefore, if one is larger than another it must empty itself less perfectly at each systole.] T This will be readily understood when I come to explain the mode of action in the valves of the arteries. OF THE VASCULAR SYSTEM. 185 heart are cut, this does not stop its motion, but rather makes it contract for the instant. The heart's motion does not arise from an immediate impulse from the brain, as it does in the voluntary muscles; and as it is only in the quadruped and bird that the nerves can be influenced in their passage to it, it does not account for this alternate motion in other classes of animals. The flowing of the blood into the heart has been assigned as a cause of its contraction; but even that will not account for it, although it will for many of its phenomena, yet not for all, for a local stimulus merely is too mechanical to produce all the variety attending the action of this viscus; it would not be attended with that, regularity which it has in health, nor that irregularity which we find in disease; neither could it ever stop, unless when absolute death took place; nor resume its action if it ever did stop. We find that those parts which have occasion for the immediate stimulus to produce action, have that action very irregular, as, for instance, the bladder of urine and intestines. The bladder is taking up its action as simply for itself, and not secondarily, however beneficial that might be for the whole in a secondary degree; but the heart's actions arise from its being so much part of the whole, as that the whole immediately depends upon it; therefore we must look out for another cause of this regular alternate action of the heart than that arising from mechanism or mechanical impression ; something more immediately connected with the general laws of the animal oeconomy. The alternate contraction and relaxation of the heart constitutes a part of the circulation ; and the whole takes place in consequence of a necessity, the constitution demanding it, and becoming the stimulus. It is rather, therefore, the want of repletion, which makes a negative impression on the constitution, which becomes the stimulus, than the immediate impression of something applied to the heart. This we see to be the case wherever a constant supply, or some kind of aid, is wanted in consequence of some action; we have as regularly the stimulus for respiration, the moment one is finished, an immediate demand taking place; and if prevented (as this action is under the influence of the will), the stimulus of want is increased. We have the stimulus of want of food, which takes place regularly in health; and so it is with the circulation. The heart, we find, cannot rest one stroke, but the constitution feels it; even the mind and the heart is thereby stimulated to action. The constant want in the constitution of this action in the heart, is as much as the constant action of the spring of a clock is to its pendulum, all hanging or depending on each other.* * [This is another of those instances in which the author has mistaken the final for the proximate cause. The feeling of hunger is obviously not the cause of the action of the muscles of deglutition, nor the sense of present danger the cause of a man's changing his position; neither is " want of repletion" the immediate cause of the heart's action. The final cause it may be, but it cannot be the immediate. In treating the question of the heart's action, two points require consideration; 186 HUNTER ON THE BLOOD. The nearest dependence of the heart is upon the lungs, and probably they have the same upon the heart. The two together

1st, what is the source whence the muscular fibres of this organ derive their susceptibility of alternate contraction and relaxation; 2d, what is the immediate cause which excites them to action. I. With regard to the first of these points, though physiologists have, with few exceptions, attributed this susceptibility to nervous influence, they have differed greatly respecting the portion of that system under the control of which they have supposed the heart to be placed. The most ancient opinion was, that the heart, like the other muscles of the body, was under the dominion of the brain ; but the well-known facts, that acephalous foetuses continue to live and grow, that the circulation may be kept up by the aid of artificial respiration for several hours after decapitation, and that in some reptiles the whole brain may be removed in successive layers without affecting the heart's action, have caused this opinion to be now generally abandoned. According to a second opinion, which originated with Legallois, the actions of the heart depend on the brain and spinal cord, but with this difference in respect of common muscles, namely, "that the heart derives its power from all parts of the spinal cord, without exception; whilst on the other hand, each part of the body besides derives its power only from a single part of the cord,—that, namely, from which it receives its nerves." This conclusion was drawn from experiments on frogs, in which the brain and spinal marrow were wholly destroyed by means of a wire introduced through an opening into the cranium. In these experiments the heart's action was entirely suspended for a few seconds, and though it recovered itself again after a short period, yet the rhythm was so altered, and the action so feeble, that no hemorrhage ensued on decapitation, or amputation of the thighs, from which he hastily inferred, that this resumed action essentially differed from what occurs naturally, and in fact resembled the action of muscles which are irritated after death. If a part only of the brain or spinal marrow was destroyed or broken down, then the action of the heart was only enfeebled, and that in exact proportion to the amount of destruction. Dr. Wilson Philip repeated and varied these experiments of Legallois, and ascertained that the spinal marrow may be cautiously removed without affecting the action of the heart; but that if this destruction be effected suddenly, as by crushing, then the action of the heart and vessels is immediately enfeebled, or else totally destroyed. He also found that the heart was highly susceptible of being affected by substances applied to the brain or spinal marrow, such as alcohol, opium, &c; and hence concluded, that though there is no necessary connexion in the way of cause and effect between the influence of the nervous centres and the motions of the heart, yet that an intimate relation exists between them. Dr. Marshall Hall has however shown, that similar effects are produced on the heart when other parts of the body are subjected to similar treatment; that alcohol, or infusion of opium, affects the heart equally when applied to the externa] skin, as when applied to the brain, and that the heart's action is equally arrested by crushing the stomach, or even the extremities, as by crushing the brain or spinal marrow; and he therefore objects to Dr. W. Philip's conclusions. Examples, indeed, of this kind occur continually to the surgeon, in which the effect of a severe crushing injury to an extremity sinks the powers of the circulation beyond recovery, although amputation of the same part might have been performed with impunity. M. Flourens admits that the spino-cerebral system, especially that part of it which administers to respiration, is necessary, to give energy and duration to the circulation; but he does not believe that this function is essentially and immediately dependent on the influence of these nerves, from the impossibility of reconciling such an opinion with the fact of the circulation going on in decapitated and acephalous animals. riie want, then, of such a connexion between the spino-cerebral system and OF THE VASCULAR SYSTEM. 187 become, in their immediate use, interwoven with the whole, for a stoppage of respiration produces a stoppage of circulation, and a

heart as is found to subsist between the former and the system of voluntary muscles, has led to the adoption, by some physiologists, of a third opinion, namely, that the actions of the heart are dependent on the influence of the ganglionic system. This opinion is less capable of being proved or disproved than either of the others, in consequence of the extreme difficulty of separating the heart from its connexions, or at least all the nerves from the heart; so that though the heart of a turtle, apparently detached from its connexions, and completely removed from the body, will sometimes continue to beat for nearly an hour, yet we cannot be certain that this action does not depend more or less on the nervous filaments which enter into its substance. Sir Charles Bell has moulded these various opinions in accordance with his own peculiar views of the nervous system, making the ordinary action of the heart to depend on the ganglionic system, but its connexion with the respiratory and sensorial functions to be derived through the cerebro-spinal nerves or par vagum; but it must be obvious that such an hypothesis is open to several of the objections urged against the opinions just stated. Not satisfied with any of the above-mentioned views, Mr. Herbert Mayo has offered an entirely different explanation of the matter. Finding that the natural state of the voluntary muscles, in the absence of any special stimuli, is that of permanent relaxation or contraction,—that when irritated, they contract by a single and momentary effort, and when divided, instantly retract; that the involuntary muscles, on the contrary, retract slowly and gradually when divided, and when mechanically stimulated take on not one, but a series of actions,—he argues that the natural state of the latter class is that of alternate relaxation and contraction, and that consequently no special stimulus is required to induce a succession of actions in these parts. "For the brief period," he observes, " during which it is reasonable to suppose that the heart retains its perfect organization, no stimulus seems required to excite it to contract. The alternation of action and repose seems to be natural to its irritable fibre, or to be the immediate result of its structure; they appear, not like similar phenomena in the diaphragm, to depend upon a series of impressions transmitted from the brain or spinal cord." There are some facts which seem to favour this view, and indeed to lead to the belief that incitability and contractility are properties inherent in and peculiar to muscular fibre totally independent of the nervous system, and that in fact the actual relation of this system to the muscular is that of supplying the stimulus to and regulating the actions of the latter in obedience to the necessities, exterior and organic, of the constitution; for, 1st, there is no proportion between the degree of contractility enjoyed by different muscles and the number and quantity of their nerves; while, 2d, local forms of paralysis sometimes occur in which no agent, either electrical or galvanic, can induce contractions in the part, although the nerves going to that part are completely unchanged. In fact, those parts which possess the smallest number of nerves, as the heart, the intestines, the stomach, &c, are uniformly found to retain the power of spontaneous contraction after death for the longest period of time, while even the voluntary muscles are obedient to the same law, and retain their contractile property much longer where the animal has been stunned previously to the experiment being made. The connexion, however, which exists between the due supply of nervous influence and the power of contraction in the muscles, is so intimate as scarcely to allow us on these grounds to consider them in any other light than as cause and effect; and one of the most weighty objections to Mr. Mayo's hypothesis is that it obliges us either to consider the former as not essential to the latter in the case of the muscles generally, or to draw a stronger line of distinction between the causes of action of the voluntary and involuntary muscles than seems in nature to exist. It appears to me that we have not yet a sufficient number of data on which to decide this question. The heart's action has been maintained by means of artifi- 188 HUNTER ON THE BLOOD. restoration of respiration produces a restoration of the circulation or heart's motion. Thus, in my experiments on artificial breathing, the heart soon ceased acting whenever I left off acting with my bellows; and upon renewing my artificial breathing, it, in a very short time, renewed its action, first by slow degrees, but became quicker and quicker till it came to its full action. I believe this experiment cannot be reversed ; we cannot make an artificial circulation, so as to know, that if we stopped the heart's motion, we should so readily stop respiration ; and on producing the heart's motion, respiration would again take place; but if we

cial respiration for upwards of two hours and a half after decapitation; and even acephalous foetuses have survived their birth several days : yet the experiments of Dr. Marshall Hall seem to warrant the conclusion that the heart's actions ultimately derive their energy from the cerebral masses, and cannot be maintained for any permanency after their removal, the circulation gradually tailing from the periphery to the centre. Although, therefore, the heart is first in the order of development, and undoubtedly ranks supreme among the vital organs in complete life—so that we should not expect it to be essentially dependent on any other—yet we have reason for believing that it is governed by all the laws which regulate the relations of similarly important organs, as well as all the laws which preside over the actions of similarly constructed parts. To whatever opinion we may come respecting the dependence of the muscular fibres of the heart on the nervous system for their power of contraction, we'can scarcely doubt that the nerves are the immediate agents through which the appropriate stimulus of the heart, namely, the blood, operates on these fibres, and excites them to action; and it may be, that this is their chief use in the ordinary actions of the heart. II. The second point to determine is, what is the immediate stimulus of the heart's action 1 We have seen that the turtle's or frog's heart may continue to beat for a full hour after it is detached from the body and entirely deprived of blood, and that a sturgeon's heart pulsated regularly for ten hours under the same circumstances (p. 123, note); but is it not probable that these actions depended on habit operating on a class of animals whose tenacity of life is extraordinary'! Under common circumstances it cannot be doubted that the heart, like every other organ, requires a special stimulus conveyed through the nerves to continue its action. Incitability and stimulus are correlative terms in physiological argument, and necessarily imply one another; and therefore to ascribe with Hunter the action of the heart to a negative impression, arising from a want of repletion in the constitution, appears to me to be perfectly contrary to the spirit of sound philosophy. There can, I think, be no doubt that arterial blood, circulating among the fibres of the heart, is necessary to maintain the incitability of this organ; but it is the distension produced by the returning blood, irrespective altogether of its quality, which is the sole stimulus of its action. The experiments of Bichat sufficiently established this fact; which is I think still further confirmed by the observation of Laennec, viz., that the ventricles during their state of repose and fulness (which occupies one-third of the time between one beat and another) do not take on their action until the auricular systole commences, or in other words until the utmost degree of distension is produced in the ventricles. See note, p. 82;—also An Essay on the Circulation, by Marshall Hall, M.D.;—Experiences sur la Circulation, by Spallanzani, tr.par J. Tourdes ;—On the Vital and Involuntary Motions, <Sfc, by R. W/a/tl, M.D.;— On the Vital Functions, by Wilson Philip, M.D.;—Du Sysirme Ncrveux, par M. Flourens ;—Man. de VInslitut, tom. x.;—Experiences sur le Principe de la Vie, par M. Le Gallois;— On the Influence of the Brain on the Action of the Heart, by Sir B. C. Brodie, Phil. Trans. 1811. p. 36;—Sur la Vte et la Mori, par X. Bichat;—and Outlines of Physiology, by H. Mayo.] OF THE VASCULAR SYSTEM. 189 could do-this, I doubt very much its being attended with equal success, because I believe that in all deaths respiration stops first; however, it must be supposed, that if the heart stopped for any length of time, respiration would also stop; and if I were to take the following case as proof, it would appear that respiration would not go on without the heart's motion. A gentleman* was attacked with a pain in the situation of the pylorus. The pain was such as indicated its seat to be in the nerves of the stomach and its connexions. It was such as he could hardly bear. The other attending symptom was a total stoppage in the actions of the heart, and of course the face was pale and ghastly. Not the least signs of motion in the heart could be felt. In this state he was about three-quarters of an hour. He was attended by Dr. Hunter, Sir George Baker, Sir William Fordyce, and Dr. Huck Saunders. As he was perfectly sensible at the time, and could perform every voluntary action, he observed that he was not breathing, which astonished him ; and at first conceiving he must die if he did not breathe, he performed the act of breathing voluntarily. This shows that breathing depends on the actions of the heart; and it also shows, that under certain circumstances the actions of both may be suspended, and yet death not be the consequence : as he spoke while in this fit, without attending to his breathing, it shows that the breathing which produces sound is voluntary; and if we had only the power of involuntary breathing, then probably we could not speak, for it is probable we could not regulate the action of the glottis and tongue (which are voluntary) to so regular an action of the lungs; for in speaking it is the one acting so as to correspond with the other, both becoming voluntary. A gentleman had a singular asthmatic affection, and his breathing gradually stopt and again gradually recovered, but became violent, and this constantly and alternately held two or three minutes; and when the breathing ceased yet he spoke, although but faintly. In those animals which have two ventricles, it has been asserted by some that their actions are alternate ; but observation and experiment show us that the two auricles contract together, and that the two ventricles also contract together. This can be observed by simply looking on the heart in its actions, and if we in that state make a puncture into the pulmonary artery and the aorta, we shall find the jet in both at the same instant, corresponding with the contractions of the ventricles. Indeed the circulation in the foetus is a proof of it, for in the child there would otherwise be two pulsations instead of one. This alternate motion of the heart is quicker in some classes of animals than others, in some being extremely quick, in others very slow. In all the more inferior orders of animals I believe it is the slowest; and this may probably be in some degree in proportion to their imperfection. It is also slower probably in each class in pro-

* [The author here refers to what happened to himself. See Life, p. 38.] 190 HUNTER ON THE BLOOD. portion to the size, and we know it is slower in each species in some degree in proportion to the size, although not nearly exactly so. The pulse is also found to be quicker in the young than in the old of each species, in greater proportion than what we find arising from size only. Thus the motion of the heart of a caterpillar is extremely slow, and also of a snail. The motion of the heart in fish is not frequent; and we know it is extremely slow in the amphibia; but in those possessed of two ventricles, as in birds and quadrupeds, the motion of this viscus is much quicker; in them, too, it differs very much, in proportion to their size, although not nearly in the same proportion. Thus, a horse's pulse is about thirty-six in a minute, while a man's is about seventy. In the same species it is nearly of equal quickness; for in a man three feet high the pulse was eighty, while a man above eight feet high had a pulse about seventy.

§ 6. General Observations on Blood-vessels.

By the vessels in an animal are commonly understood those canals which carry the juices of the body, called the blood of the animal, to and from the heart, for the immediate purposes of the animal ceconomy; and in those animals where no heart is to be found, yet vessels are found, though their uses are not so demonstrable; and in some of a still more inferior order, where no vessels can be demonstrated, yet, from analogy, canals may be supposed to exist, and those should still be called vessels.* The vascular system in an animal is, in some degree, to be considered as the efficient part of the whole animal respecting itself, every other part of the body being more or less subservient to it, and depending upon it for existence and support; and therefore the greatest attention should be paid to every circumstance that can possibly explain the various uses of the vessels, for there is no operation respecting the internal ceconomy of the animal but is performed by them, insomuch, that for the convenience of the vessels in performing those peculiar actions, they seem to constitute

* Of this I am not certain. I have an idea that some animals absorb their nourishment, even without action, somewhat similar to a sponge, but dispose of it immediately by converting it into their own increases a [Ellis the celebrated zoophytologist and a contemporary of Hunter, believed that he saw motions or actions in the mouths of the sponge analogous to those in the mouths of polypes; but it now generally believed that he was deceived and that the ingestive orifices are passive, and that so far as they are concerned the nourishment is absorbed in the sponge, as Hunter states, without action. By what mechanism within the nutrient canals of the sponge the currents which perpetually traverse them are produced has never been determined : analogy points to the vibratile action of extremely minute cilia as the cause. With respect to the canals which are continued from the stomach, and which convey by their ramifications the alimentary fluid directly to the parenchyma of the animal, these are beautifully exhibited by means of coloured injections in some of the parenchymatous Entozoa and the Medusae in the preparations Nos. 843-848 in the Gallery of the Hunterian Collection.] OF THE VASCULAR SYSTEM. 191 various combinations, which are called organs.* And althouo-h many parts have actions independent of the vessels, yet these are not for the purposes of growth, support, etc. So that the vessels are constructed for the immediate use of the machine, and may be called labourers in the machine. This naturally implies something that is not vessel or vessels, a something that constitutes the different parts of the body, and is only more or less vascular. The vessels are probably the very first active parts in the system, for we find them in action before they have formed themselves into a heart, and in such a state of parts we find them theonly part that has any strength, while the other parts are only preparing for action ; this is so remarkable, that we can dissect the vessels of a chicken in the egg without injection, the other parts easily giving way. These parts are formed of living animal matter, so composed as to constitute the different structures, fitted for their different uses, in the machine ; yet some parts are so vascular as to appear almost to consist wholly of vessels, as if vessels were formed into such structures ; but this we cannot conceive, for then they must lose the action of vessels. In those animals where the vascular system is connected with a heart, which may be called the. termination as well as origin of the vessels, we find that viscus to make so material a part of this system as to require particular attention. In many of these animals we find two systems of vessels, the arteries and veins, and most probably they exist in all of them ; there is also a third which consists of the absorbents. The heart is the source of the arteries, and the termination of the veins and absorbents. The two first, depending on each other, form the circulation ; and the third is essential to both, bringing the materials which are to circulate.t The arteries are to be considered as the acting part of the vascular system, since they perform a variety of actions the uses of which are very important in the animal oeconomy. They may be called universal or constitutional, for their actions are immediately productive of health or disease in the constitution ; and if they could be diseased as a system, that disease would of course be universal; as their actions are expressive of health or disease, they become also one means of discovering either. There is no internal operation in the machine, respecting growth,

* Perhaps it may be difficult to give a definition of an organ that will meet every one's ideas, or will distinguish those bodies accurately from what may be said not to be an organ. A muscle may be called an organ, but I would only consider it among the materials of which an organ is composed. I have the same idea of elastic substances, cellular membrane, bone, cartilage, etc. I would, at present, define an organ to be a part of a particular construction, composed of a variety of substances, [elementary structures,] which are combined together to answer some particular purpose, which is the result of the actions of the whole. f This system is too extensive to be described in the present work, although it will be necessary to describe one use not hitherto attributed to it, as it explains one part of my system of disease. 192 HUNTER ON THE BLOOD. natural repair, and secretion, that is not performed by them. ISo new part is formed, nor additional alteration made in the structure of natural parts, nor repair for the loss of natural substances, either by disease or accident, but is made by the arteries, although of all these operations we know nothing but from the effect produced. These operations are performed by the termination of the arteries, which may be supposed to be of three kinds: one may be called arteria], conveving debilitated blood into the veins, and through their whole length may be called arteries ; another kind consists of the separators from the blood, performing the different secretions; and the third contains the formers and supporters of the body : the two latter kinds I should not call arteries; they are the workers, or labourers.*

* [The only evident termination of arteries is into capillaries, carrying red blood, which are plainly distinguishable from any other set of vessels, as well by their uniformity of size as by the peculiarity of their mode of division and reunion. The arteries pursue a straight course, and up to a certain period are observed to divide and redivide in a regular series of bifurcating divisions ; the blood always flowing from trunk to branch, and the branch being uniformly found to be smaller than the trunk. After a certain period, however, the artery is observed to break abruptly into an irregular network of vessels, consisting of an intricate interlacement of capillary tubes of uniform cylindrical diameter, which divide and redivide, unite and reunite by an infinite number of anastomoses, presenting, especially in the pulmonic circulation of some of the batrachian animals, a beautiful and splendid device. The current of blood in these vessels is probably more than twice as slow as in the smallest arteries, but in consequence of the extremely devious and intricate course which it takes, it is next to impossible to follow any single globule through the mazes of its route into the veins: which veins again, I may observe, are formed by a re-collection of these tubes into the veaous radicles, which uniting by twos and twos, in the reverse order of the arteries, ultimately form the venous trunks. The venous radicles are not unfrequently observed to anastomose with each other, but rarely or never the minute arteries ; neither is it ever observed that these latter terminate directly in the veins, but the transition is uniformly effected through ihe interposition of a capillary structure, which is proportionally more developed in the lungs than in the other parts of the body. In the arteries the blood is of a lighter colour than in the veins, and has a much greater velocity of motion ; but in the capillaries the colour and velocity of the blood are uniformly the same, although the slightest disturbing causes are sufficient to make it flow faster or slower, or even to take a retrograde course where before it took a forward direction. In an unimpeded state of the circulation the pulsation is barely visible in the arteries, and not very distinctly so in the capillaries; but it may be rendered distinctly so in both, as well as in the veins, by impeding the course of the blood, by which the tension is increased so as even to produce a remarkable oscillation of the globules. I have seen the globules advance and retire over a space at least twenty times their own length at each pulsation of the heart, and this for an unlimited length of time. One reason, I imagine, that the pulsation is not more visible in the minute vessels in the natural state of the circulation is, that our senses are unable to appreciate the differences of velocity of bodies in very rapid or very slow motion ; a cannon ball passing before our eyes at the rate of twenty miles an hour appears to go at the same rate as one at sixty miles, just as the hour-hand of a watch would still appear to go at the same rate as if it went twice as slow. Now as the actual area of the artery comprised in the focus of a high magnifying power is extremely small, at the same time that the apparent rapidity of the current is proportionably increased, the difference between the velocities in the systole and diastole of the heart is not perceptible. The differ- OF THE VASCULAR SYSTEM. 193 The absorbing system also takes a very active part in the animal ceconomy, whether natural or diseased, and seems in many actions to be the antagonist of the arteries ; while the veins are much more passive, being principally employed in returning the blood to the heart. It is probable that every part of the body is equally vascular, although they may not all have equal quantities of blood passing through them, which must arise from the smallness of the vessels, and not from their being fewer in number. When we say that a part is very vascular, we can only mean that it is visibly so, by having a large vessel or vessels going to it, and ramifying in it; from which circumstance it contains a certain proportion of red blood, rendering the vessels visible, which may also easily be made conspicuous by injections. Where the vessels are smaller this is not the case. When we say, therefore, that a part is not vascular, we mean it is not visibly so; but still we must suppose such parts to be equally vascular, so far as respects their ceconomy within themselves: but in such parts I conceive the blood to be more languid in its motion. Many parts appear to be much more vascular than they really are, from their vessels dividing and anastomosing, and taking a winding course before they terminate ;* for it is

ence in the degree of tension is certainly not the only cause of the difference in the degree of pulsation. I have said that the'arteries never directly communicate with the veins, but always through avascular network ; and this is strictly true in all warm-blooded animals, in which the systems of black and scarlet blood are preserved distinct. In inferior animals, however, as fish, the Batrachia, and even in the embryos of warm-blooded animals, as, e. g., in the chick during the first days of incubation, such communications are found to exist, because in these instances it is not of the same importance to keep these systems apart. The term capillary therefore ought exclusively to be applied to this intermediate system of vessels, which appears essentially to differ both in function and distribution from any other parts of the vascular system. SeeSchidlz,in Journ. de Progres des Sc. Med., vii. 1828, and Dr. Marshall HaWs Essay on the Circulation, 1831. Besides this visible system of capillaries, there can scarcely be any doubt that another system (invisible in consequence of its not admitting red globules) also exists. It is impossible otherwise to explain the nutrition of white structures, such as cartilage, the tunics of the eye, &c, or the phenomena of inflammation, when these structures become inflamed. The appearance which these colourless vessels assume when they become enlarged leads us to believe that they are similarly arranged as the coloured capillaries, and it is not improbable that all the processes of nutrition are carried on in these vessels. Hallerand Bichat, and indeed most other physiological authorities, have superadded two other terminations to the arteries, viz., the exhalant and excreting vessels ; especially as in the liver, kidneys, and some other glands, injections may be made to pass from the arteries or veins into the excretory ducts. I am not aware, however, of any single fact to show that there is more reason in favour of the exhalant and excreting vessels of Bichat than of the lateral porosities of Mascagni. This doctrine may be true, or it may not be true ; but it certainly cannot be recognised at present as one of the undoubted facts of science. The same may be said of the "workers, or labourers," of Mr. Hunter.] * By simply cutting into the spermatic artery [cord ]] of a bull it appears to be extremely vascular, though, according to our idea of vascularity, it is as little so as any part. 17* 194 HUNTER ON THE BLOOD. by the number of terminations of an artery in a given space that a part is made vascular or not vasclar; muscles appear to be more vascular than they really are. When parts have another use, in which blood furnishes the materials to be disposed of, as in secretion and respiration, where vessels fitted for such purposes are superadded, then parts become proportionablv more vascular. When blood does not seem to be the matter to be "disposed of, yet, if there are other operations continually carried on in a part, besides its simple support, as in a muscle, which has both the power of contraction and considerable sensation, &c, then the vessels are larger, and of course appear in great numbers. This is evident in the living body, for if a muscle is hardly allowed to act, its vessels become small, and it becomes pale ; but if thrown into more violent action for a continuance, it becomes red: we cannot here suppose an increase of vessels, but only an increase of size. Thus we have parts vascular in proportion to the quantity of action they are capable of, or under the necessity of, performing: and this particularly in parts whose uses may be called double, as the organs of secretion in general, brain, and muscles ; even in inflammation, and in proportion as these parts are employed in their peculiar actions, they become to appearance more vascular. Some animals have naturally red muscles, without its being the effect of considerable action ; this is very remarkable in the hare ; but the redness in the muscles of this animal may be intended to adapt its muscles naturally for violent exertions at all times. Muscles are of different colours, respecting red and white, in the same animal; but that I believe is also in proportion to the quantity of action the parts are put to. This effect the epicure is well acquainted with: he knows that the wing of a partridge is whiter than the leg, and that the leg of a woodcock is whiter than the wing. The veal of this country is a remarkable instance of this: for the calf is hardly allowed to stir, and the muscles are white; but when the calf is allowed to follow its mother, the muscles are of a reddish colour. It may be, however, remarked that white meat is commonly the least juicy ; and we find it remarkable so in those animals which are fed for this purpose, because, they require nothing but their simple support, and having little or no action within themselves, they have but little waste. Such change of appearance we find carried to a considerable extent in the uterus at the time of the menses ; but much more particularly at the time of uterine gestation, where the vessels increase both in size and length, in proportion to the actions required. But parts whose use in the machine may be said to be passive, as tendon, cellular membrane, ligaments, investing membrane, bone, and cartilage (which last is probably the most passive), have all small vessels, and of course but few that are visible. As bone, however, is composed of two parts, viz., animal substance and earth, it is probable there may be more action required to form the latter than either tendon or cartilage, and therefore there will be more vessels. OF THE VASCULAR SYSTEM. 195 As a further proof that this is a general principle, we find that all growing parts are much more vascular than those that are come to their full growth; because growth is an operation beyond the simple support of the part. This is the reason why young animals are more vascular than those that are full-grown. This is not peculiar to the natural operation of growth, but applies also to disease and restoration. Parts become vascular in inflammation: the callus, granulations, and new-formed cutis are much more vascular in the growing state, or when just formed, than afterwards; for we see them crowded with blood-vessels when growing, but when fullgrown they begin to lose their visible vessels, and become not even so vascular as in the neighbouring original part, only retaining a sufficient number of vessels to carry on the simple ceconomy of the part, which would now seem to be less than in an original part. This is known by injections, when parts are in the growing state, or are just grown, and for some time after. We may observe when the small-pox is cured that the remainsof the pustules are red and continue so for-some time, which is owing to those parts being visibly more vascular than common; and those who have had the smallpox severely are in general afterwards more pale than others, when those parts have arrived at their permanent state. If we cut into a part that has had a wound or sore upon it which has been healed for a considerable time, we shall find that the cicatrix and the newformed parts are not nearly so vascular as the original, which corresponds with what has been advanced, for we know that those parts are not equal in power to original parts. In short, whenever Nature has considerable operations going on, and those are rapid, then we find the vascular system in a proportionable degree enlarged. The number of vessels in a part, and also the circulation of the blood through them, appear to keep pace with its sensibility; for first we find that most probably all parts endowed with vessels are sensible, and all sensible parts are to appearance very vascular. Where any increased action is going on, requiring increased sensibility, there is also an increased circulation through those vessels, as in the parts of generation during the time of coition, more especially in the female; and this increase of vessels, circulation, and sensibility in a part takes place in disease; as is well illustrated in inflammation, where the whole seems to be increased in the same proportion, especially the two last, viz., circulation and sensibility. These observations can only be made in animals which have red blood, and best in those which have the most red blood ; but it is not possible to ascertain with accuracy the proportion that one blood-vessel bears to another, so as to know the exact quantity of blood each part may possess, which would better ascertain the action of the part; for they may be said not to be measurable with any degree of accuracy, and therefore such calculations must be taken in the gross. Vessels have a power of increase within themselves both in dia- 196 HUNTER ON THE BLOOD. meter and length, which is according to the necessity, whether natural or diseased. The necessity appears to arise from an increase of the part to which the artery is going, the formation of a new part, or an irritation. The first may be reckoned the natural increase of the body: the second, the occasional increase of parts, as of the uterus in uterine gestation, where the vessels are increased in width in proportion to the whole solid contents, including the young; besides this, they are considerably increased in length before they reach the uterus, which obliges the spermatic artery in particular to be thrown into a serpentine form ; this is more remarkable in some animals than in the human species. Instances of newformed parts where the vessels are increased, are to be found in the stag, or all those of the deer kind which cast their horns, such animals having the arteries considerably increased at the time the young horn is growing, so that the carotid arteries, which before had only to supply the head and the external carotid, which before had only to supply the sides of the head, now become larger, and are continued into the horn, which is extremely vascular. After the separation of the foetus, or the full growth of the horn, the vessels naturally lessen, to adapt themselves to the diminished size of the parts. It is curious to observe how vessels become enlarged upon any irritation, not only the arteries, but the veins, and not only the smaller branches, but the larger trunks. This was evident in the following case ; I applied a caustic to the ball of the great toe of a patient every other day for more than a month, and after each application the surrounding parts puts on a blush, and all the veins on the top of the foot, as well as up the leg, immediately began to swTell, and became large and full. This was so remarkable that the patient watched for this effect on the days on which the caustic was applied, from its happening only on those days. In diseases where there is an increased size of the part, as in tumours, etc., the increase of vessels is no less conspicuous, and they have the power of dilatation and increase of strength, in proportion to the size of the vessels, which are now endowed with new dispositions and actions, different from those they had before. The arteries often perform diseased operations in the body, which become symptoms both of local and constitutional actions, as in inflammation, fever, etc., for they are not only active in local disease, but their action often becomes a symptom of a constitutional disease, whether original, or arising from a local cause ; but these symptoms become mostly sensible to us in those arteries whose actions we can feel, because they have a peculiar action in their diastole as well as in their systole, which is sensible to the touch, from which sensation we in many cases judge of the state of the body at the time, as also of the state of the cause; when it is local and out of sight. The heart, the source of the circulation, is also affected from the same cause, so that its motion and the motions of the arteries commonly if not always correspond. OF THE VASCULAR SYSTEM. 197 § 7. Valves of Arteries.

The arteries arising from the heart, I believe in all animals, have valves, which are so many flood-gates, to hinder a return of the blood into the cavities; and as there are two main arteries in the human body, so there are two sets of valves, viz., one belonging to each artery. These are situated at the beginning of the artery, and, from their shape, are called semilunar. Veins have similar valves almost through their whole course. The valves are inelastic, being similar to the inner coat of an artery ; but the difference in the properties of the valves and the arteries themselves (which are elastic) will be further considered in treating of the use and mode of action of the valves. Each of these sets is made up of three valves,* but in veins there are commonly only two. This difference in the valves of the arteries and veins is perhaps to bring the artery into a more rounded figure than could have taken place by two valves only : each of these valves is of a semilunar form, having one convex edge, and the other nearly straight. These valves are attached to the insides of the artery, at its very beginning, by their semicircular edge, which is oblique, the points, as it were, running a little way into the artery. These terminations in each valve come close to one another, but the loose edges, which constitute the diameter, are not cut straight off, but rounded. There is, besides, a small body on each, attached to or near the edge, between the two points, called corpora sesamoidea. These bodies are not placed exactly on the edge, but rather on that side next to the artery, leaving the edge of the valve loose: this situation is best adapted to their intended use; the reason of the loose edge being a little rounded, and of the bodies called corpora sesamoidea being placed there, arises from there being three valves to each artery. Each of these valves, with its artery, forms a pouch, whose mouth or cavity opens towards the artery; and the convexity of each of the valves, when the artery is dilated, makes nearly the third of a circle, which is turned inwards towards the centre of the artery, as well as towards the heart. It is from this oblique direction in the attachment that the valves perform their office, simply from the action of the heart upon the blood, and the blood upon the artery. This is entirely mechanical, depending on mechanical principles alone, as much as the action of a joint. I have above observed, that the area described by the valves is the same with the artery when that vessel is in its systole, their outer surface lining the inner surface of the artery ; but the artery being elastic, its diameter becomes larger when the blood flows into it; and the valves being inelastic, their loose margins or edges are

* I have found in the human subject only two valves to the aorta; but this is very rare. [Mr. Mayo has figured a similar case in his Outlines of Physiology, 3d Edit. p. 54.] 198 HUNTER ON THE BLOOD. brought more into straight lines across the area of the mouth of the artery, and nearer to each other, so as to make an equilateral triangle. Thus they are fitted to catch the returning blood, and the artery, reacting with considerable force on the blood, presses it on the valves, so as to push them inwards; these, having no pressure on the side next the heart, become convex on this side, shutting up entirely the mouth of the artery. Here then is an effect arising naturally out of a variety of causes, viz., the oblique direction of the valves, their want of elasticity, the elasticity of the artery, and the dilatation of the artery; so that the return of the blood'does not open the mouths of the* valves, and in that way shut up the mouths of the artery. To demonstrate this, let us suppose the extreme length of each of these valves to be an inch; then the circumference of the artery, when in its systole, will be three inches: in that case the valves lie close to the sides of the artery, and describe a circle of three inches circumference (as in PL III. f. 3.); but if you dilate this artery as far as the valves will allow, which will be rather more than one-fifth, the valves will run nearly into straight lines, and make an equilateral triangle (as in PI. III. f. 4.), whose sides are a little curved inwards. As the artery is filled from the contraction of the heart, it is distended ; and as it is distended, the valves do more and more their duty, till at length, by the full distension of the artery, they are made to bulge inwards, and the loose edges, with the corpora sesamoidea, are pushed further towards one another, by all of which positions the area of the artery is entirely shut up.* PI. III. f. 3. shows the artery in its systole, with the three valves, nearly close to its sides. The two black dots are designed to represent the mouths of the coronary arteries, now covered by the valves. Fig. 4. shows the artery in its diastole, where the three valves

* [If so great a dilatation of the artery, as is supposed, actually takes place during the systole of the ventricle, the effect upon the artery and valves would be different, I conceive, from what is represented in the text; for taking the extreme length of the valves to be one inch, and the circumference of the artery, in its systole, as three inches, and in its diastole as three inches -f- \ (which is the case supposed by the author), then would the artery, during its systole, dilate unequally, in the same manner as is observed in regard to veins; and instead of a circle, as in fig. 4. PI. III., would be thrown into a form exhibited in fig. 6. ; that is, the dilatation of the artery would take place at all points, excepting where the valves are attached ; but there, in consequence of the inextensibility of these bodies on the one hand and the impossibility of their assuming a straight direction on the other, while the pressure from behind remains, the artery would bulge out in the intermediate spaces. The use of this arrangement is very evident, as it tends to keep the edges of the valves (aaa, fig. 5.) partly patent, in readiness to catch the returning current of blood the moment the systole of the artery commences. According to the explanation of the author, the area of the artery would be partially closed, as may be observed by inspection of fig. 6, and thus offer a considerable obstruction to the complete evacuation of the ventricle; besides, the degree of dilatation necessary to make the valves form an equilateral triangle is probably greater than ever takes place, particularly in debilitated states of the circulation.] OF THE VASCULAR SYSTEM. 199 run nearly into straight lines, making an equilateral triangle of the area of the aorta. But as their edges are rounded, and the bodies of the valves make a curve inwards, they by these means fill up in part this triangular space, as is seen at d d d; and the corpora sesamoidea fill up the remaining other part at e e e. In this way the whole of the area of the artery is filled up. The foregoing account is proved by injections against the valves: but it is still more clearly proved that the diastole of the arteries make the valves do their duty, when it is injected with the current of blood; for in proportion as the artery is distended, the valves recede from the sides of the artery; and if the artery is fully distended, the communication is entirely cut off between the two pieces of injection, viz., that which is within the heart and that which is within the artery.* It may be objected here, that it will require a certain quantity of blood to make these valves do their office; and when there is not that quantity, it must be done by regurgitation. To this it may be answered, that nature always keeps a due proportion, and all the parts depend on one another; so that the quantity of blood that is just sufficient to keep the animal alive is sufficient to distend the artery so as to shut the valves.f The valves of the pulmonary artery do not do their duty so completely as those of the aorta, for in them we do not find the corpora sesamoidea ; and if we inject a pulmonary artery towards the right ventricle, it does not so completely hinder the injection passing into that cavity; nor are the two portions of injection completely separated when the artery is injected from the ventricle, as in the left side. So far as respects injections, the same observations are applicable to the valvulas tricuspides; therefore I believe the valves of the right side of the heart are not so perfect as those of the left; and from hence we may suppose that the universal circulation requires to be more perfect than that through the lungs. We must see from this account of the action of the valves, that the mouths of the coronary arteries are opened by the action of the heart; for as the arteries dilate, they become more and more exposed.

§ 8. Of the Division, or Branching, of Arteries. As all the arteries in animals possessed of a heart arise from or begin at that heart by one or two trunks only, they are obliged to

* [This is very far from being conclusive. The reaction of the elastic parietes, which have been previously distended by the injection, drives the blood back again upon the valves, and closes them. I may observe, that the semilunar valves are not, generally, so perfectly formed as accurately to close up the area of the artery, while the tricuspid and mitral valves are still less perfect.] f As people advance in life, especially men, we find the aorta losing its elasticity ; and as it is acted upon with great force by the impetus of the blood, it loses that elasticity in the state of its diastole, which throws the valves continually across the area of the vessels ; and as the valves in those cases commonly become thicker, and are often very irregular and bony, we find that they neither recede from the sides of the aorta, during the contraction of the heart, nor towards it during the systole of the artery ; so that more blood is allowed to regurgitate into the ventricle, than in a regular circulation. 200 HUNTER ON THE BLOOD. divide into or send off branches or smaller trunks, which again divide into still smaller, till at last the whole body is supplied by the ultimate divisions. This is called the branching or ramification of arteries, and is somewhat similar to the branching of a tree. This branching of an artery does not depend on the artery itself, or on the powers propelling the blood, as in a tree, but is governed by the formation of the body; that is, according as a greater or less quantity of blood, or a greater or less velocity is necessary to different parts. Various modes of branching are made use of to answer the above purposes. In general the most favourable mode for the free passage of the blood is adopted, viz., branching with acute angles, more especially those which are to carry the blood some considerable way; and still more so in those which are at a great distance from the propelling impulse of the heart, which I shall now more particularly consider. As the force of the blood in the artery is stronger the nearer it is to the heart, the difference in the velocity of the blood, near and at a distance from the heart, if there was nothing to retard it, would be too great for the difference in parts; the near and the distant parts being in many instances of the same kind. To keep up a velocity sufficient for the parts, and no more, nature has varied the angle of the origin of arteries, at different distances from the source of the circulation. Thus we find that near the heart the arteries arise by obtuse angles ; some of them being reflected, and the angles become less and less, till at length they are very sharp. The most remarkable instances of this are the intercostal and lumbar arteries ; for these being a set of branches whose length and uses in the body are nearly the same, the difference is made in the greater obtuseness of the angles at which they arise in proportion as they are nearer the heart, as well as in the greater distance which they have to traverse in a retrograde direction from their origin to the parts supplied.* We find a difference even in the arteries which arise from the intercostals; for they are much more obtuse at the beginning of the intercostals than at their termination. The reason why this is not so evident in all the arteries of the body is, that there are so few arteries on the same side of the body which take the same course, to go to the same distance, and have the same office: forsome parts require a greater velocity than others, which will make a difference in the origin of the two arteries, supposing they should go the same length and take the same course. We see the same thing in the secondary arteries, such as the subclavian; for it sends off its branches near its origin at much more obtuse

* [This passage I have ventured to alter. In 1st Edit, it stands thus : "The most remarkable instance of this is in the intercostal and lumbar arteries ; because, since they are a set of branches in the body whose length and uses are so much the same, if there be any difference in the angles, at the origin of the arteries, at equal distances from the heart, it must be made with regard to their length, from the origin to the part supplied."] OF THE VASCULAR SYSTEM. 201 angles than it does further on. Haller, in his Physiology, says that the arteries arise at an angle of forty-five degrees, which is the greatest angle in projection; but he did not consider that in projection there are two powers, viz., gravitation and the force applied, while the blood in the arteries has only one. It may be asked whether the blood in an artery of a given size, arising from a large one, is sent with the same force as if the artery had arisen from a much smaller trunk, or from an artery of the same size with itself, whose blood passed with the same velocity as in the large one. We find small arteries coming off at once from large ones, instead of being a third, fourth, or fifth from the large ones. Arteries send off their branches at a longer or shorter distance, according to circumstances; or, in other words, they divide and subdivide more quickly in some places than in others. I believe this quick division is more peculiar to glands than most other parts, though it does not take place in all, as in the testicle. They divide also quickly in the substance of the brain. In the kidney this is also remarkable; they would seem in that gland to be hurrying to their termination. The same happens as soon as the arteries enter the substance of the brain. Other parts appear to have the arteries elongated before they enter the part, as the spermatic artery; more especially in some animals, as the bull, boar, &c.; and in the female, in the time of uterine gestation, where we should expect the quickest circulation, we find the arteries elongated very considerably, which throws them into a serpentine course: all of which must retard the blood's motion in the part. We also find arteries playing in the parts, ramifying and anastomosing, which diminishes the velocity of the blood, such aa those of muscles, membranes, &c. We may suppose, from the foregoing instances, that in some a quick supply of blood was necessary in such parts; in one for the drain, in another for the support of the living powers; while in others a more regular, slow, and even motion answered the purpose better. Arteries in comm'on pass in as direct lines from their origin to their destination as possible ; but this is not universally the case, for in many parts they run in a serpentine manner, so much so in some as to form a body of themselves. Thus, the spermatic artery in the male of many animals, more especially the bull, is so convoluted as to form a body. In the female also the spermatic artery increases its serpentine course in the state of uterine gestation. The internal carotid artery in man and many other animals, as the horse, where it passes through the skull, runs in a serpentine direction; and in the lion, bull, &c, it forms a plexus. This would appear to answer two purposes: one to lessen the impulse of the blood, as in the vertebral and internal carotid, spermatic artery, &c.: the other to allow of the stretching of the parts upon which the arteries passes, as the mouth or lips, the uterus, and other parts of the body which admit of being stretched or relaxed, as the bladder, stomach, intestines, &c, independently of their elasticity. 202 HUNTER ON THE BLOOD. We find not only the different systems of vessels communicating with each other, as the arteries with the veins, the veins with the heart to be continued into the artery again, and the absorbents with the veins to communicate in the end with the whole, but also the branches of each system communicating with one another, which is called anastomosis. Anastomosing of vessels is the opening of one vessel into another; so that if one of them be prevented from carrying its contents, the office can be performed by the other. The most common mode of anastomosing is when two vessels run into one, or are continued into each other, or one vessel opens into another, from which others arise; but there is a peculiar communication between the two carotids, as well as between them and the vertebral, where a canal of communication passes directly between them, and this mode of communication takes place between the two descending aortas of some of the amphibia.* This anastomosing is much more frequent in the smaller than the larger arteries. We seldom find trunks anastomose with one another. One reason for this is the great disproportion in number between the larger and smaller arteries; but the anastomosis is much more frequent in the smaller, in proportion to their number. The use of this is to give freedom to the circulation, as the chance of a stop being put to it is greatest in the smaller arteries, the circulation in them not being so strong, and passing through parts liable to be pressed upon. This is readily seen in the transparent parts of the living body, when viewed through a microscope. In some parts of the body we find anastomoses in pretty large trunks; but these are in parts essential to life, very liable to be compressed, or both. The mesenteric artery anastomoses by large trunks; the mesentery being a part essential to life, and very liable to compression, from indurated fasces compressing the artery. In this case, if they only anastomosed by the small branches, on the intestines, the circulation might not be kept up sufficiently to preserve the gut. We observe the same thing in the brain; for there the arteries anastomose by large trunks, before they are distributed to the brain. The use of this is that all parts of the brain might have an equal quantity of blood at all times, even where accident had put a stop to the circulation in any one vessel; for the small

* [A similar construction is sometimes observed in the human subject, and has been figured by Tiedemann in his Tabulae Arteriarum, PI. iv. fig. 7. I may observe, by the way, that the arch of the aorta, or rather the great trunks which arise from the arch, are subject to more variations from the normal type than perhaps any other artery in the body. It has generally been thought that the venous system presents greater and more numerous anomalies in its distribution than the arterial; and this observation is undoubtedly true as far as regards the superficial and smaller vessels, but not as regards the deep-seated and more considerable trunks. The aorta, for instance, is subject to at least twenty-nine varieties, in regard to the vessels which arise from its arch, whereas only one has been observed with respect to the vena cava superior, viz., when the right and left subclavians do not join previously to their reaching the heart. So likewise the renal and brachial arteries are much more irregular than the corresponding veins.] OF THE VASCULAR SYSTEM. 203 anastomoses on the pia mater would not be sufficient to keep up a due circulation everywhere in the brain; as I believe the arteries do not anastomose in the substance of the brain itself. There are large anastomoses in the hand and foot, for the same reason as in the intestines. All the uses arising from the anastomosing of the vessels, are, perhaps, not yet perfectly understood: general reasons can, I think, be assigned for them; but these will not apply to all cases : there is something, therefore, more than we are yet acquainted with. The absorbents and the veins, upon the whole, anastomose more frequently than the arteries; yet that circumstance is reversed respecting the veins in some places, and in these instances the uses of these systems of vessels are also in some measure reversed. Where all the three systems of vessels have nearly the same mode of action, we find that their manner of anastomosing is somewhat similar, and probably the difference might be easily accounted for. Wherever they appear to be simply carriers, then their mode of anastomosing is somewhat similar: however, the absorbents anastomose more frequently than the veins, and the veins more than the arteries, and probably the absorbents anastomose everywhere. This is not so much the case with the veins, and not in the least so in some parts with the arteries. Let us see if we can assign reasons for all this variety in the different systems of vessels. The absorbents, from the office of absorbing, are to be considered only as carriers ; and as they have no propelling force applied to their contents, and their coats are not strong, it is very probable that a free communication between vessel and vessel should take place; upon the same general principle the veins also anastomose, although perhaps not so frequently, and this difference may be because they have in some degree a propelling power applied to their contents, namely, the action of the heart. The arteries having a very strong propelling power applied to their contents, it was in them not necessary as a general principle ; but where they are placed in similar circumstances we find them similar in this respect. Although the anastomosing of vessels is upon a general principle very proper, yet in many cases it would appear to be very improper, as in the following parts. The arteries do not anastomose in the kidneys. This cannot arise simply from there being no occasion for it, on account of there being no lateral mechanical obstruction : since, from the same mode of reasoning, the veins should not anastomose, which they do very freely. This want of anastomosis in the arteries, therefore, answers some purpose in the ceconomy of the part. In the liver, the branches of the vena portae do not anastomose, although the arteries do in their smaller branches ; we may therefore suppose some particular purpose answered besides free communication; and I believe the arteries do not anastomose in the substance of the brain, which makes the brain appear less vascular than it really is. We may observe, perhaps, as a general 204 HUNTER ON THE BLOOD. principle, that arteries near to their destination, where they are to perform their particular functions, do not anastomose. Thus the artery of the kidneys, the vena portae,* the arteries in the substance of the brain, do not anastomose; nor do the arteries on the villous coat of the intestines. If it be questioned whether anastomoses are a means of retarding or accelerating the circulation, I should answer that they appear to me to retard the blood's motion,f although we find vessels anastomosing as freely with one another at the greatest distance from the heart as near to it; but at the same time we may observe, that where we should suppose it was necessary for the circulation to be brisk we find no anastomoses in the arteries, as in the lungs, the kidneys, and I believe hardly in the liver, except on the peritoneal coat, whose arteries are continuations of the hepatic artery. I believe that the anastomosing of vessels increases their volume on the whole, and therefore allows a greater quantity of blood to be in them than if they did not. That kind of network too which they make increases the magnitude of the vascular system ; for to answer this purpose they take lateral and circular courses, which give them greater length than if they had simply passed between origin and destination in straight lines. The better to ascertain the velocity;}; of the blood in the arteries at the different distances from the heart, it will be necessary to know whether an artery be a cylinder or a cone; and, when it divides into any number of branches, whether the whole of these taken together be less, equal, or greater than the vessel or vessels from which they arose ; and therefore whether they hold less, the same, or more blood. It may be observed that arteries keep a pretty exact proportion with each other, the branches with the trunk, &c, through the whole system ; and therefore, whatever may be their shape, they preserve it pretty regular: viz., if they are cylindrical, they are so regularly; if conical, the same. I should suspect, however, that the anastomosing of the arteries, in some degree, interferes with this regularity; but it is probable that the ultimate branches may come back again and correspond with the original trunk. To ascertain this, it is necessary to make choice of arteries which for some length either send off no branches,

* This vessel should be considered as an artery. X [There can, I think, be no doubt that anastomoses retard the circulation, on the same principle as the current is retarded in passing from a smaller into a larger tube; also by opposing currents. See note on capillaries.] I [Dr. Young estimated the mean velocity of the blood in the aorta at 8 inches per second ; but less in the smaller vessels, in proportion to the gradually increasing area of the vascular cone (Med. Lit., p. 609, and note, p. 45). The velocity, however, will necessarily differ in different vessels, according to the obstruction which it meets with, although this is scarcely at all found to affect the arterial tension, which, according to the experiments of Poiseuille, is almost exactly the same in all parts of the body. The ventricles are estimated to throw out about one ounce and a half to two ounces at every contraction, and the whole blood to perform about twenty complete revolutions in every hour.] OF THE VA8CULAR SYSTEM. 205 or at least such as are very small when compared with the trunk: for it is impossible to measure with any degree of accuracy the size of branches, and then calculate their different capacity, in comparison with that of the trunk from whence they are derived; and I think it is reasonable to suppose that, whether an artery divides or not, the size must be the same in both, for it is necessary that the ultimate effect should be the same. The arteries which are best adapted for this experiment are those of the placenta and of the testicles, particularly in the bull. The carotid arteries in some animals are tolerably well formed for experiments of this kind; for though these do not give us the exact proportions which the one end bears to another, yet they plainly demonstrate which end is the largest. The arteries of the placenta evidently increase in size the nearer they approach to the placenta ; and this so very considerably as to require no experiment unless it be intended to ascertain the difference correctly. In the spermatic artery of the bull it is equally evident; but as these arteries are much longer than the distance between their origin and the parts which they are to supply, it may be supposed that this increase is peculiar to them, in order to answer some particular purpose. But the carotid arteries in some animals afford sufficient proof that the arteries in common become larger as they pass on and ramify; for the carotids may be reckoned ramifying arteries, as they send off branches. The carotid artery of the camel among quadrupeds, and of the swan among birds, are very proper arteries for such experiments. To be as accurate as possible, I injected the arteries of two camels and the arteries of a swan; and, that one end might not be more distended than the other, the artery was well warmed and placed in a perfectly horizontal position. The pipe wa sfixed into the lower end,* and the injection made so warm as to keep fluid some time after having been injected : in this position it was allowed to cool. I made sections from each end; and, that they might bq perfectly equal, I took a hard piece of wood, an inch thick, and bored a hole through it of the size of the artery, so as to contain a section exactly of that length, having a moveable button fixed at one end, which could be turned upon the hole, or off, at discretion, The artery being introduced through the whole, a projecting part was cut through by a thin knife, in order that the artery might be divided at right angles to itself. After doing this, the artery was withdrawn, and the button was then turned upon the hole, so as to stop that end, and the cut end of the artery introduced to the bottom or button; this piece so inclosed was separated in the same manner. Having taken a piece of the carotid artery from each end, which were of course exactly of equal lengths, I weighed them, and found

* The fixing the pipe into the lower end was rather in favour of increasing the size of this end. IS* 206 HUNTER ON THE BLOOD. that the section of the upper end was one grain and a half heavier than that of the lower. The carotid artery of another camel, measuring three feet and a half in length, was found to send off forty-four small branches, about the size of the human intercostal arteries, with one as large as the ulnar. Of this artery a transverse section, of one inch in length, being taken'from each end and weighed, that from the lower end was found to weigh two scruples sixteen grains and a half, while that from the upper end weighed only two scruples fourteen grains and a half. In similar sections of the opposite carotid, which sent joff forty-seven branches, the difference in weight between the upper and lower section was five grains. Similar sections from carotid arteries of a swan being weighed, the lower sections were found to be three grains and a half heavier than the upper: the lower section weighing thirteen grains and a half. Had the lateral branches been preserved an inch long, being the length of the sections of the trunk, I believe each might have weighed above a grain; and, in that case, the forty-four would have been nearly equal in weight to the trunk. Should this be true, the arteries increase very considerably, not only in their ramifications but in their trunks. I imagine if the carotid artery in the camel did not send off any branch in its course, it would increase in size, nearly in the same proportion with the umbilical artery, or the spermatic in the bull. It is to be observed that as arteries divide they increase in size much faster than if they did not. For instance, if a section of an artery two inches long is equally divided into two, the section that is the further from the heart shall be heavier than the other, perhaps by one grain; but if the most distant section had divided into two branches, the two, taken together, would have been a grain and a half heavier; if three branches, two grains heavier, &c. The increase of size in the arteries as they ramify is an effect of the numerous ramifications.* From what has been already said it must appear that arteries form a cone, whose apex is at the heart; and, if this be the case in the adult, we shall find that it must be more so in the young subject, and will every day become less as the child increases in growth. The capillary arteries in the foetus are probably as numerous as in an adult; perhaps more so, for we know that there is the same number of principal arteries in each ; as far as we can trace them, they seem to send off the same number of smaller branches; and in many parts we find a great many more small vessels in the foetus than in the adult. In the eye, the membrane of the ear, &c, in all growing parts, such as callus, granulations, &c, we find a great

* [A part of this increase in weight must be laid to the account of the increased superficies of the coats of the vessels. The solid contents only should have been weighed in order to have rendered these experiments perfectly accurate.] OF THE VASCULAR SYSTEM. 207 many more vessels than in similar-grown parts, or in the same parts when completely formed; not in proportion to the size of the part but more in number. These are strong proofs that many arteries are obliterated in the adult. How much more vascular, therefore, must a child be than an adult, in proportion to its size, when in a much smaller compass a greater number of arteries are accumulated !* From this it would appear that the only great change in the vascular system is elongation [and enlargement] of the vessels: for, as we find very little difference between the blood of a foetus and of an adult, it is natural to infer that the smallest vessels are nearly of the same size in both; for the termination of the arteries, or what may be called the operative part of the arterial system, being intended to perform the same functions in the foetus as in the adult, it is reasonable to suppose that the increase is in the length [and diameter] of the whole vascular system; and that the increase in the size of the trunks is in a uniform gradation from the capillaries towards the heart, but never [in their aggregate capacity] becoming equal to the capillaries. If the preceding account be true or nearly so, we see that there must be a great proportional difference between the size of the two extremes of the arteries in the young subject and the adult. We may venture to say that the aorta in the child is not one-fourth of the size of that vessel in the adult, and that the capillaries are rather larger than those in the adult, which would of itself make the whole capillaries in the foetus more than four times the size of the aorta in the same; and as these arteries are very short, the cone of course increases very fast. In the foetus in utero we are to consider that the aorta, at the beginning from the ventrical, is larger than in the adult, in proportion to the quantity of blood that passes through the foramen ovale : and beyond the entrance of the canalis arteriosus the aorta is increased in proportion to the size of the canalis arteriosus ; and it is at this part its size is to be estimated. This probably makes the aorta, beyond the entrance of the canalis arteriosus, twice as large as in the adult in proportion to their size; but the drawback upon this, from the body, is the placenta; for the placenta is to be considered as part of the body, disposing of the blood that afterwards circulates through the lungs: however, when it is separated, it may take away with it nearly its own proportion of blood, although I rather suspect it does not. But I do not suppose it is equal to the quantity passing through the foramen ovale and canalis arteriosus; and if so, then the body has the overplus,

* [It should not be forgotten, however, that there are other parts which become developed and require a large supply of blood in the adult. We may instance the muscular system, which can scarcely be supposed actually to contain an equal number of capillary vessels in the infant as in the adult. Some organs also, as the genital, must surely have a larger supply of vessels in the adult than in the infant.] 208 HUNTER ON THE BLOOD. The aorta of a foetus is, therefore, not only larger than that of an adult, but larger than in that proportion which the size of the foetus bears to the size of the placenta. Or it may be put in this view: that, besides the difference in the size of the aorta in a young subject (as before observed) and in an adult, the size of the aorta in the foetus is still larger, viz., more than in that proportion which the circulation in the lungs of the adult bears to the circulation in the lungs of the foetus, which is probably much more than that of the placenta.* Experiment on the Arteries of a Child.—I injected the descending aorta of a foetus, just above the diaphragm, in the same manner as I did the carotids in the camel and swan, by which means I injected the mesenteric artery, the subject of experiment. This artery has a trunk, which at first does not put off branches, and then sends off several, which may be all called so many trunks. These again do not immediately give off branches, and are therefore measurable with the trunk from which they arise. I first made a section of the trunk of the mesenteric artery, near its root, before it sends off any considerable branches, one-third of an inch in length; and then another section of the same artery, having the same length, close to the origin of the first branch: all the branches arising from it being preserved of the same length with the trunk itself. When they were weighed in opposition to each other, the trunk without the branches was found to weigh thirteen grains and a half; while that with the branches weighed eighteen grains, that is, four grains and a half more than the trunk. A section of the aorta, near half an inch long, being made just above the origin of the inferior mesenteric artery, was weighed against a section of the same length, including the inferior mesenteric, likewise of the same length ; the last section weighed one grain more than the other, the highest amounting to six grains, the lowest to seven. A section of the lower end of the aorta, including a portion of the two iliacs, was weighed against a section of the two iliacs, which was equal in length, and these were found to weigh rather heavier. By the above is confirmed what I formerly asserted, than an artery not giving off branches does not increase so fast as another which does if we include all the branches. From all that has been said it appears that there must be a much greater quantity of blood in the foetus than an adult in proportion to their difference of size; and that the heart must be larger and stronger, in proportion, to move this blood, which will probably still circulate in the smaller vessels with less velocity. The whole of these differences between the foetus and the adult must be intended for the purposes of growth: and indeed we may

* L1 apprehend the author's meaning to be simply that the excess of the adult pulmonary circulation over the foetal (which excess must previously have passed through the aorta) is more than equal to what formerly went to supply the placenta. Consequently the body must have had the overplus"] OF THE VASCULAR SYSTEM. 209 discern the necessity of it; for if a child was not more vascular in proportion to its size than the adult, its growth, we might conceive, would only be in proportion to the number of its vessels, which would be twelve times less than they are, for a new-born child is only one-twelfth in size to that of an adult. A child would, therefore, grow faster and faster every year, for instance, in proportion to its size, as the vessels would become numerous in that proportion. But this is not really the case, for children grow less and less every year in proportion to their size, only adding their first year's growth to themselves every succeeding year; though, perhaps, not quite so much, as the vessels rather decrease in number. That this is the case may be proved by taking the eye for an example, which grows more the first year after, conception than it does any year afterwards; so that the disproportion between the vessels of this part, in those two states, is particularly great. The growth of an animal is, therefore, in proportion to the number of its capillary vessels. As the body grows, the vessels elongate to keep pace with that growth, the capillary vessels at last come to a stand, and the arterial system is daily losing ground. The heart grows in proportion to the increased length of arteries, that it may be able to throw the blood through the whole, but not in proportion to the size of the whole body, because the vessels do not increase in number or size in proportion to the size of the body. But as the heart increases only in proportion to the size of the whole vascular system, while the body increases faster and more, the heart cannot be in proportion to the size of the whole body, hence its action must in time lose the power of elongating the body; and become merely sufficient to nourish what is already formed. Perhaps it does not even continue to do so much; for it is not impossible that the body may begin to decline from the moment it ceases to grow, the heart having pushed the growth of the body even beyond its own powers to preserve it in that state.

§ 9. Of the Action of the Arteries, and the Velocity of the Blood's Motion. Arteries, during their diastole, which arises from an increased quantity of blood being thrown into them, increase much more in length than width, being thrown into a serpentine course; therefore, instead of the term diastole, it should rather be called the elongated state. It is, however, the increased diameter that becomes sensible to the touch.* This probably arises from the muscular coat oppos-

* [The question of the immediate cause of the impression of the pulse has been a subject of considerable dispute, respecting which modern physiologists are by no means perfectly agreed, particularly as to the degree which the vessel enlarges or lengthens at each systole of the heart. The diametrical enlargement of the artery was altogether denied by Parry, Laennec, and Bichat; but not apparently with good reason, for it is very visible in the immediate vicinity of the heart in several reptiles. Haller observed it in the chick, Magendie and Hastings in the thoracic aorta of the horse, and Meckel and Tiedemann in the 210 HUNTER ON THE BLOOD. ing the dilatation of the arteries, while it cannot the lengthening. The dilatation of the artery producing the stroke is either felt by the finger or may be seen, when superficial; but were we to judge of the real increase of the artery by this we should deceive ourselves, for when covered by the integuments the apparent effect is much greater than it really is in the artery itself: for in laying such an artery bare, the nearer we come to it the less visible is its pulsation, and when laid bare its motion is hardly to be either felt or seen.

smaller arteries. The reason why it is not generally more visible appears to me to be this. The carotid artery of an animal, measuring a, or^V of an inch in diameter, being exposed for six inches, the elongation which this length ot vessel is supposed to undergo at each contraction of the ventricle is estimated at i, or r%%, of an inch ; so that, supposing the diametrical enlargement to take place only in the same proportion, it would not amount to more than -ljnr Part°J an inch, which it would be difficult under any circumstances to see, and still more difficult in a unilateral aspect of the vessel. When, however, we further reflect that the time required for the transmission of a wave of blood from the heart to the most remote part of the body does not exceed a half secondhand then calculate the extreme velocity with which this wave passes over a few inches of vessel, we shall not be surprised at not being able to perceive it. Besides, the mere fact of exposing a vessel is sufficient of itself to induce the contraction of its coats, so as completely to obliterate the tube ; from all which circumstances I conclude that very little reliance can be placed on these kinds of observations. The experiments of Poiseuille, which seemed to evince that an actual enlargement took place, are not perfectly conclusive. The elongation of an artery is barely appreciable in an undisturbed state of the circulation, but may be rendered distinctly visible by holding the nostrils of an ass (whose carotids have previously been exposed) until the respiration becomes laborious. The artery may now be observed to leap from its bed, and to become elongated and tortuous at each stroke of the ventricle; effects which may be imitated in the dead body, or on dead tubes, by forcible injections, and which are also observed to occur naturally in many parts subjeet to violent periodical excitements, as the testicle and uterus. It has been observed, however, that a tangible shock may be conveyed through a fluid much in the same manner as sound, so that we may discover the working of a water-pump at a great distance merely through the pipes, whether iron or leathern, by which it is connected. Others have ascribed the pulse to the forward rush, without tumefaction, which takes place when an additional quantity of blood is injected into elastic vessels. It may be observed, however, that any elastic vessel, as, for instance, an intestine, perfectly full of fluid is capable, on being gently tapped with the finger, of communicating a rapid and distinct pulse to a great distance, although no forward rush can take place, but only a gentle undulation. Dr. Parry, however, has justly observed, that the impression of the pulse may be rendered much more obvious by slightly pressing on the artery thus fl >—*^~H so as to indent it, by which means the finger becomes directly opposed to the current of blood. We occasionally hear of instances in which the pulse is said to vary, as well in its rhythm as in the number of its beats, in different parts of the body; but probably all such cases are resolvable into some irregularity of the heart's action: as when, for instance, it is partly intermittent, so as to give first a perfect and then an imperfect stroke—the perfect stroke only being sufficient to communicate the pulse to the extreme parts, although both may have this effect on those which are in the immediate vicinity of the heart. It is difficult, if not impossible, to assign specific causes for the numerous variations of the pulse which takes place in disease. The sphygmometer, lately invented by M. Herrsson, is perfectly inefficient, and is not deserving of the least confidence.] OF THE VASCULAR SYSTEM. 211 The more an artery is covered, especially with solid bodies, the more is the pulsation to be felt or seen; thus, tumours over large arteries have a considerable motion given to them, and have often been supposed to be aneurisms. The knowledge of this fact, arising more from experiment than common observation in the living body, may be a sufficient reason for keeping to the old expression, dilatation. This circumstance, which has been but little taken notice of, produces an effect which has also been unobserved. If the arteries had been dilated by the force of the blood's motion, as has been supposed, its motion should be much less retarded than it is; for even supposing that the increased area of the artery is the same when elongated as if dilated, and therefore holds an equal quantity to a dilated one, it must appear evident that the blood will not arrive so quickly at the opposite end.* The continual repetition of the cause of this serpentine course obliges the arteries in many places to retain this state, especially in parts that do not yield readily, as the skull, upon which the temporal artery is placed; and this retention of the serpentine course is still more obvious in those arteries which have lost a good deal of their elasticity. However, this increasef of the artery is so, manifest as to be felt or seen, and produces what is called the pulse, which must gradually diminish in proportion as the arteries divide into smaller branches; for a small artery having a proportional pulse, and the arterial system increasing as it goes along, both of which causes diminish the velocity of the blood, and render the diastole less and its motions more uniform.

* [Sir C. Bell, in his " Essay on the Forces which circulate the Blood,'''' has endeavoured by an ingenious train of reasoning, to prove the reverse of this position ; for, observing that most organs which perform or are liable to be called upon suddenly to perform any extraordinary degree of action, as the uterus, brain, testicles, &c, are provided with highly tortuous vessels, he argues that this arrangement must be designed to give greater power to the local circulation, so as to increase the velocity of the blood in those parts, as occasion may require, without necessarily engaging the whole vascular system in this act; and this is supposed to be accomplished by the increased muscular superficies giving greater strength to the tortuous artery. We cannot, however, argue from final causes in such cases as this; neither can we at present, with any degree of precision, say how iar the muscularity of the arteries is actually concerned in carrying on the ordinary circulation. We do, however, know, on physical principles, that the multiplication of angles, and the increased superficies of a tortuous vessel, must have the effect of retarding the current which passes through it; while, on the other hand, we know that°the mere force of impulsion from behind is sufficient to produce a tortuosity of the vessel, as well of the arteries and veins as of inert tubes; but as it is not pretended that the veins assist the circulation by their muscularity, the tortuosity in them can neither arise from the cause assigned, nor be attended with the effect supposed. It is probable, therefore, that the tortuof>ity is produced by the same cause in both orders of vessels, and that it is attended with

^ViD^es the'author mean by » this increase," the elongation or the diametrical enlargement of the artery ? The preceding part of the paragraph would seem to point to the former meaning; but in the first paragraph of this section he says, »It is the increased diameter which becomes sensible to the touch, ] 212 HUNTER ON THE BLOOD. From the description I have given of the heart with its action, and the parts of which an artery is composed, it must appear that an artery is at all times full of blood, which is moving on with more or less velocity ; because it receives it from the heart at interrupted periods, and when a given quantity is thrown in at one end, this will make a considerable difference between this part and the other, which part will of course be more upon the stretch; for although the artery dilates, yet as it is from the impulse of the blood, the blood must move much faster on the diastole of the artery than its systole. This part of the artery will contract, and throw the blood into the remaining part; but not with the same force with which it was received; but still the artery beyond will receive it faster than it will give it. By these means, all the parts of the artery are brought to a more equal state ; for this additional quantity of blood that was at first in one part only, is in some degree equally diffused through the whole arterial system ; by which means, too, it is becoming proportionably slower in its motion: but all these circumstances will vary according as the arterial system consists of cylinders or cones; and if of cones, then according to the extremity which is the base; all of which may be conjectured, but cannot be exactly estimated. Yet that the force of the heart might not be lost, the elasticity of the great artery, over the smaller, is happily applied, because it propels the blood more forcibly on, between the strokes of the heart; for although we are to suppose that the heart, which was capable of distending a part, so as to make it react, and send the blood through any given length, was also capable of sending it through that length at once, yet we must see, that by an elastic power being applied at one end, while this is gradually lost towards the other, the elastic part acts with a superior force over the other, in the proportion as the other has less elasticity. This other being also less upon the stretch, is overcome by that which is more so, which is always the end next to the heart; for the muscular part relaxes, requiring hardly any force to distend it; and indeed, as the muscular power has contracted the artery within its middle or stationary state, and this more and more as we get into smaller vessels, the muscular coat is at first stretched by the recovery of the elastic power; so that the blood passes into the smaller branches with much less resistance than it would have done if the vessels had been elastic in proportion to their size. These proportions, however, in the blood's motion, arising from the elastic power of the arteries, will not be the same in the foetus and adult, and will be still more different in the aged subject; for in this last the elastic power of the artery is diminishing as well as the muscular, the coats becoming more rigid ; besides which, the vessels vary from a conical shape (whose apex is at the heart and basis at their extremities) towards a cylinder; and this change is also increased by the loss of many of the smaller vessels; so that as we grow up, the base of the cone is gradually diminished from two causes. OF THE VASCULAR SVSTEM. 213 The elastic power will allow of a quantity of blood in the animal beyond the natural state of the artery, and the muscular power will allow of a smaller, without the animal being affected, although the muscular alone would have answered both these purposes. Arteries, then, are the conductors and disposers of the blood: as conductors they are, in every animal above fish, both passive and active; passive, in admitting of the propelling power of the heart, and active, in continuing that power to the extreme part. Besides these reasons for a difference in the velocities of the blood at different distances from the heart, I conceive there is a material difference between the velocities of the blood in those vessels which carry red blood, and those which carry only the coagulable lymph and the serum; for where the red blood goes, there is a quicker return than where there is only the coagulable lymph and serum. For this there are two reasons, viz., that where the red blood passes, it is commonly nearer to the heart, while the other parts go to a greater distance: but besides this, the vessels which carry the red blood are larger, and, I believe, ramify more quickly ; the velocity, therefore, of the blood is greater in them. Where the lymph and serum pass only, the velocity of the blood is languid, and it appears merely to carry nourishment, such as in tendons, ligaments, etc. So far we are to consider the above as a general principle arising out of the construction of a blood-vessel ? but there are secondary or collateral circumstances acting, so as to accelerate or retard the blood's motion. Since the solids and fluids have a mutual dependence on each other, and since the solids answer various purposes, for which quantity, velocity, etc., are peculiarly necessary, we find that this intercourse between the two is with great exactness kept up. I have already observed that the angles at which the branches of an artery arise, either retard or allow of a freer motion in the blood; but Nature appears to have taken still more care in retarding the blood's motion where velocity might do mischief. She seems also to have taken more care about the blood's motion in some parts than in others; as, for example, in the brain, a part which probably cannot bear the same irregularity, in quantity or velocity of the blood, as many other parts of the body. I should suppose, that by sending four arteries to the brain, instead of one, or which would have been more regular, two, the force of the motion of the blood is broken, as well as by the winding course of the internal carotid arteries. The tortuosity of the vertebral arteries, likewise, are intended, we may suppose, to prevent a too great velocity of the blood, both because these arteries are longer than they need be, and the blood is hindered from moving in a straight line: but, besides the serpentine course of the arteries of the head, they pass through a bone (but principally the carotids), where the bony canal is closely applied to the coats of the artery ; so that there can be no pulsation here, but a greater velocity of the blood in those parts, 214 HUNTER ON THE BLOOD. and probably less in the brain. This I should suppose retards also the motion of the blood in the brain, because the blood, passing through a smaller place than common, must meet with a greater resistance, and therefore a smaller quantity must pass through this part in a given time, so that the pulsation of the arteries in the brain should be less than anywhere else ; for we may suppose that the motion is considerably lost by the blood coming into an elastic canal of the same diameter with that through which it passed before it came into the bony canal. If, then, this motion is lost, and the quantity of blood is really lessened in a given time, its motion must be more regular, and the pulsation less. In some animals the carotid artery is found to divide and subdivide, forming a plexus, and the branches unite again before it goes to the brain. This is called rete mirabile, and in animals which have it will certainly break the force of the blood's motion; but since it is not universal, some peculiar purpose must be answered by it. It is not in the horse and ass, for instance; but it is in the lion. Where the vessels anastomose, there is also a considerable retardation to the blood's motion, and they are found to anastomose a good deal on the pia mater before they enter the brain, but I believe not within its substance.

§ 10. Of Veins. The vessels* carrying the blood from any part of the body towards the heart are called the veins; they are more passive than the arteries, and seem to be, from their beginning to their termination in the heart, little more than conductors of the blood to the heart, that it may receive its salutary influence from the lungs. However, this is not universally the case, for the vena portas would seem to assume the office of an artery in the liver, and therefore becomes an active part; and we have many veins formed into plexuses, so as to answer some purpose, not at all subservient to the circulation; but still, in this respect, they are not to be reckoned active. They differ from the arteries in many of their properties, although in some they are very similar. They do not compose so uniform or regular a system of vessels as the arteries, either in their form or use, being subject to considerable variety in their uses (which are, however, passive, not active), and often answering, from their construction, collateral purposes. The coats of the veins, upon the whole, are not so thick as those of the arteries, but differ materially in different situations of the body. Thus, they become thinner and thinner, in proportion to their size, the nearer to the heart; however, this is not equally so through the whole venal system, but principally in the depending veins, as

* A vein is commonly a canal, especially that which carries red blood; but in many animals it is entirely cellular; yet I use the word as a general term when applied to the blood. OF THE VASCULAR SYSTEM. 215 those of the extremities, more especially the lower in man ; and still more so, the nearer to the extreme parts. In such parts it is often difficult to distinguish the vein from the artery; yet this is not to be remarked in the veins of ascending parts, or those coming from the head, or such as are horizontal, especially in the human subject; and in animals which have a large portion of their body horizontal, there is little difference in the coats of such veins at different distances from the heart. I suspect the muscular powers are much greater in what may be called ascending veins, than either descending or horizontal; and I believe, in general, it is very considerable, for if we look at the back of our hand, and compare their size in a warm day or before a fire, and in a cold day, they hardly appear to be the same veins. They are not so strong in their coats as the arteries, and their strength is in an inverse proportion to their size in the extremities, and the reason is very obvious. They are more dense in their coats than the arteries, yet in the dead body they seem to admit the transudation of the blood ; for when there is the least degree of putrefaction "we can trace the veins with the eye on the skin, as if very large, the cellular membrane and the skin being tinged for some way on each side of the vein. In the liver we find injections escaping the vena cava hepatica, and getting into its substance in a peculiar manner. They have nearly the same elasticity with the arteries ; they are similar to the arteries in their structure, being composed of an elastic and muscular substance,* the elastic in some degree preserving a middle state, although not so perfectly as in the arteries. The muscular power adapts the veins to the various circumstances which require the area to be within the middle state, and assists the blood in its motion towards the heart. The coats of the veins themselves are vascular, although not very much so. The arteries arise from the nearest small ramifying arteries, and the corresponding veins do not terminate in the cavity of the vein to which they belong, but pass off from the body of the vein, and join some others from different parts, and at last terminate in the common trunk, some way higher. On laying open the jugular vein of a dog, and closing up the wound for some hours,

* [The veins are less elastic, but much more extensible than the arteries ; and in proportion to their substance, are capable of sustaining a much heavier weight without breaking. The internal coat of veins, besides being much thinner, more delicate, and less fragile than that of the arteries, is remarkably distinguished from the latter, by never becoming the seat of ossifications, which, in the arteries, take place so generally in rather advanced life as almost to be considered the normal state. It is remarkable that this disposition to ossification is, as Bichat remarked, strictly confined to the arterial portion of the system of red blood, commencing from the left auriculo-ventricular opening, through all the ramifications of the aorta; for the left auricle, and also the pulmonary veins, although they carry red blood, are rarely, if ever, affected in this manner. The fibrous coat of veins is principally seen in the depending and superficial veins of the body ; but in general it is very obscurely developed, and in some veins cannot be said to exist. The fibres, according to Meckel, invariably run longitudinally, and from this circumstance are strikingly contradistinguished from those of the arteries.] 216 HUNTER ON THE BLOOD. and then opening it, I observed the vessels of this part very distinctly. They were becoming inflamed, therefore turgid, and I could easily distinguish between the arteries and veins by the colour ol the blood in them. -,, Veins have interruptions in their cavities, called valves, lney are thin, inelastic membranes, of an exact semilunar form, their unattached edge being cut off straight, not curved, as in those ol the arteries; and this is because there are only two of them w.iose semicircumference adheres to the sides of the vein. They are not placed in a transverse direction, so as to cut the axis of the vein perpendicularly, but obliquely, as the valves at the beginning of the arteries, making a pouch whose mouth is turned towards the heart. They are attached in pairs, the two making two pouches, whose edges come in contact. In the larger veins of many animals, as the jugular veins of a horse, &c, there are often three valves, as at the beginning of the aorta, but not so completely formed. These valves, as it were, cut the veins into two at this part. These two valves are not always of equal size. At this part there are always two swellings in this form, but I believe more in the adult than in the young subject. They are not formed from a doubling of the internal coat, as has been imagined, for the internal coal is elastic, but the valves are rather of a tendinous nature; from this circumstance, together with their shape and their mode of attachment to the sides of the vein, they always do their office whenever the vein is full, in the same manner as the valves of the arteries. The valves of the veins are chiefly in the extremities, jugular veins, and the veins on the exterior parts of the head, but never in the veins of the brain, heart, lungs, intestines, liver, spleen, nor kidneys. Where a smaller vein opens into a larger there is often a valvular structure at the acute angles, but this is not constant.*

* [Single valves are often found to occur in veins of not more than a line in diameter, and occasionally also in the larger trunks; but sometimes three, four, or even five valves have been discovered where two only ordinarily exist. The valves are composed of a fibrous substance, lined by the internal membrane of the veins. Valves very rarely occur in anastomosing or azygos vessels, for obvious reasons. Generally speaking, the number of valves is increased in the same ratio as the Bize of the vessels is diminished; but this extends only to a certain point, for after that the inverse ratio seems to be followed, so that in the smallest veins the valves disappear altogether. Valves are uniformly most numerous in depending and superficial parts, because in these parts the "auxiliary aid of the valves is most needed to assist in carrying on the circulation of blood. The following veins, in addition to those enumerated in the text, possess no valves, viz., the umbilical, vena cava inferior, vertebral, and veins of the spinal marrow. The uterine veins and also the spermatic veins in the female are not generally provided with valves although they occasionally exist. There is a remarkable deviation in the structure of the veins of the brain, adapted to the peculiar circumstances of that organ : for, in the first place, the sinuses are rendered incompressible, to guard against their being collapsed by any sudden increase of the arterial tension, which the inextensibility of the cranium would necessarily determine to these vessels, so as to compress their sides together; while, in the second place, this provision is rendered still more perfect, by the tributary veins of the pia mater being made to open into the sinuses in an OF THE VASCULAR SYSTEM. 217 The veins, taken altogether, are much larger than the arteries;* but in the extremities the veins that attend an artery are sometimes less. Nevertheless, there are commonly two of them ; but, besides these, there are superficial ones, which are much larger than those deeply seated. The best way, however, of judging is by comparing them with the corresponding arteries where there are no supernumerary veins, as in the intestines, kidneys, lungs, brain, &c, where we find that they are larger than the arteries: and this too where a considerable waste has taken place of the arterial blood in the different secretions. From this circumstance the blood's motion in them is slower, and they allow a greater quantity to be in the body at all times. There is a greater number of trunks of veins in the body than of arteries, at least visible veins, for wherever there is an artery in common there is a vein, and in many places two, one on each side, which sometimes makes a kind of plexus round it; besides, there are many veins where there are no corresponding arteries, as on the surface of the body; for in the extremities many of the larger veins pass superficially, but those become fewer and fewer towards the trunk of the body. They are numerous also in the neck of the human subject; but in some of the viscera, as the intestines, the veins and arteries correspond in number very exactly. Dr. Hales, however, in his Statics, says that he has seen a number of arteries throw their blood into one vein; which, if true, shows that there are more small arteries than veins. Although veins generally attend the arteries, there are some exceptions, even in corresponding veins, as in the pia mater; but they cannot all attend the arteries, there being more superficial veins on the extremities and neck, but the large trunks do. The supernumerary veins are not so regular as those that attend the arteries, being hardly alike in two people. The veins may be said, upon the whole, to accompany the arteries, and it is most reasonable that this should be the case; since both perform the same office of conducting the blood, the same course must answer equally in both. This, however, is not universally the case, some veins being intended for particular purposes, as the vena portae; some forming bodies, as the penis, plexus retiformis.-f and others varying their course for convenience, as in the brain. The veins of this viscus take in general a very different course from the arteries; but this is principally in the larger veins of the brain, for the smaller, which are in the substance, accompany

oblique direction, opposite to the current of blood, so as effectually to oppose any reflux determination, upon the circulation being impeded.] * [This, however, is more apparent than real in the dead body, in consequence of the continued action of the capillaries driving the blood into the dilatable veins.] f [See Principles of Surgery, p. 46, note. There can scarcely be any doubt that all the phenomena exhibited by the erectile tissues are due to the extreme extensibility of the venous tunics.] 19* 218 HUNTER ON THE BLOOD. the arteries. The intention of this seems to be that the largest veins, called the sinuses, should be so formed as not to be compressible, probably that there should be as little chance as possible of any stoppage to the circulation of the blood in this part. But in some parts of animals they vary their course from the arteries, where we do not so well see the intention, because it is not the case in others. Thus the veins in the kidneys of the cat-kind and hyaena have the veins in part passing along the surface in the external membrane, like the sinuses in the brain. Veins seldom or ever take a serpentine course, because a retardment in the blood's motion in them answers no particular purpose in the ceconomy of the parls, and the more readily the blood gets to the heart the better. However, the plexuses, although not intended to retard the motion of the blood, answer other purposes not immediately connected with the circulation. Veins upon the whole anastomose more frequently than the arteries, especially by their larger trunks, and more particularly in the extremities; for we often see a canal of communication going between two trunks, and one trunk shall divide into two and then unite again. Where the veins and the arteries correspond, their anastomoses are nearly the same. I believe they do not anastomose in the lungs or liver; however, the veins corresponding to the arteries do not always follow this rule; for the veins in the spleen and kidneys anastomose in very large trunks, while the arteries do not at all. This anastomosing of the larger veins more frequently is because a vein is easily compressed and the blood has a ready passage into another; besides, the valves render it more necessary, for when the blood has got past a valve it cannot take a retrograde course, but may take a lateral: and indeed it. is principally in those veins which have valves that we find those large anastomosing branches; by this means the blood gets freely to the heart. As the area of all the veins is larger than that of the arteries, the blood will move more slowly through them; and this is evident from every observation that can be made. It may be observed in the large superficial veins in the extremities of the" living body, and the difference of velocity in the blood flowing from a vein and artery in an operation is very great. The blood, however, moves with a good deal of velocity in a vein, for if we stop the circulation in the beginning of any of the superficial veins of an extremity, and empty the vein above, immediately upon removing the finger the blood will move along the vein faster than the eye can follow it: yet its motion is so slow as to allow the blood to lose its scarlet colour, and acquire the modena red ; and this more so as it passes on to the heart. The blood moves more slowly in the veins than in the arteries, that it may come into the right auricle more slowly; for if the two venae cava? were of the same size with the aorta, the blood would have the same velocity in them ; which the auricle, as it is now constructed, could not have borne; but it may be probable, that the OF THE VASCULAR SYSTEM. 219 blood is assisted in its passage into the auricle by a kind of vacuum being produced by the decrease of the size of the ventricles in their contraction. From the number of anastomosing branches, especially by larger trunks, from the blood being liable to temporary obstructions in many places, and also moving with little force, its course becomes often very irregular and undetermined, much more so than in the arteries. The first cause of the blood's motion in a vein of a quadruped is the force of the heart, for I think we must suppose that the heart can and does carry on simple circulation} because, in paralytic limbs, where voluntary.muscular action is totally lost, and where, I conceive, the involuntary is very weak, the circulation is continued, although I believe, with much less velocity than in perfect and sound parts; besides, we have observed, that the arteries continue the motion of the blood in them where the heart either fails to do it, or where an increased motion may be wanted. The arteries, therefore, will assist the heart in propelling the blood through the veins; however, it is assisted by collateral causes. The second cause is their muscular contraction, which most probably is in the direction of the blood's motion, assisted by lateral pressure of all kinds; because the valves will favour this course wherever they are. However, as the valves are not universal, the motion of the blood in some veins must be carried on without them, and therefore they are not absolutely necessary. Since we see the veins assuming the office of arteries in the liver of quadrupeds, birds, amphibia, and fish, and much more so in many of the inferior orders of animals, the motion of whose blood is first derived from the heart, we must suppose that veins have considerable power in carrying on the circulation ; but the resistance being continually removed at their termination into the heart, will direct and assist the blood's motion in that direction, more especially when influenced by the action of the vessels themselves, or any lateral pressure. In those veins which are accompanied by the arteries, the pulsation of the artery assists in propelling the blood towards the heart, more especially where there are two or more attending an artery. When treating of the motion of the blood in the arteries, I observed that its motion was not in a uniform stream, but interrupted, which arose from the heart's action; but as it receded from that viscus, that its motion gradually became more uniform, till at last it was nearly a continued stream. However it is not certain but an alternate accelerated motion is continued into the veins immediately from the heart, although it may not be an easy undertaking to ascertain this; for simply observing an accelerated motion in the blood of the veins, more especially the small ones, does not prove that this was an alternate increase immediately from the arteries. Every artery has a pulsation in itself, immediately from the heart; 220 HUNTER ON THE BLOOD. but a secondary vein, or one that is a third or fourth in order of size, cannot, because it has more than one cause acting upon it; for such vein is receiving the impulse of the heart at very different times, owing to the larger trunk receiving blood by a number of smaller veins that come from a variety of parts: so that if the trunk was to receive it by starts from the smaller veins, it would only be a tremor or confused motion. This is a reason why this cause could produce none in the secondary veins.* The fact is, however, that there is a pulsation in the veins, for when we bleed a patient in the hand or foot we evidently see a strong jet, much more in some than in others, and much more here than in the bend of the arm. The query is, does this arise from the immediate stroke of the heart, or is it by the lateral pressure, occasioned by the swell of the arteries ? To ascertain this the better, it is necessary to observe several things: we may remark that the pulsation in the veins is more in some parts than in others ; thus, I should suppose it was more in the veins of the kidney, spleen, lungs, and brain, especially the last, than in many other parts; but this, from the lateral swell of the arteries, cannot, from the above observations, affect all parts alike, for the veins on the back part of the hand being superficial, and not surrounded with vascular parts, could not be affected by arteries: but still it may arise from the lateral swell of the smaller arteries; and this acceleration, given to the blood's motion in the smaller veins, is carried to those on the back of the hand. But I think I have seen the difference in the projection so great, that it hardly could arise from that cause alone; and indeed, if this was the only cause, we should have it in some degree in every vein, for every vein is so far surrounded as to be in some measure affected from the swell of the arteries of the part; but we

* [The unintermittent continuity of the venous current arises solely from elasticity ; for supposing the whole vascular system to consist of rigid tubes, the impulse would of course be instantaneous in every part of this system. It is not, therefore, the different lengths of the veins, but the great extensibility of these vessels which equalizes the current. This it is which gives to the veins the operation of an air-vessel (note, p. 168), or compressed spring, the effect of which will be to transform the intermittent impulse of the heart into a continuous force. This may be proved by increasing the tension of the veins in a frog's leg, by partially retarding the circulation, when the pulsation immediately becomes visible in the small veins as well as arteries; although the reaction of the former soon equalizes the tension of the whole vessel, and thus prevents the propagation of the impulse to the larger trunks. I think it probable that the pulsation which is sometimes perceived in veins of the third or fourth class, as, for instance, in those of the arm, is due to a cause of this kind increasing the tension of the whole venous system, especially as a hard contracted pulse in the arteries is often associated with this appearance in the veins. In those cases where a pulsation is visible in the great veins, in the neighbourhood of the chest, it undoubtedly depends on the reflux of the blood on each systole of the auricle, or of the ventricle, if there should happen to be at the same time any disease of the heart, as, for instance, hypertrophy, attended with imperfect construction of the right auriculo-ventricular valves. The respiratory pulse is not synchronous with that of the arteries, and depends on too obvious a cause to require explanation.] OF THE VASCULAR SYSTEM. 221 Certainly do not perceive it in so great a degree in the bend of the arm. The larger veins near to the heart have a pulsation which arises from the contraction of the heart preventing the entrance of the blood at that time, and producing a stagnation. This I saw very evidently in a dog whose chest I opened, and produced artificial breathing; but I could not say whether this arose from the contraction of the auricles, ventricles, or both: but the vena cava superior has a contraction in itself, in both dog and cat, and probably in the human subject. Even breathing produces a stagnation near the thorax, for during inspiration the veins readily empty themselves, but in expiration there is a degree of stagnation. Coughing, sneezing, or straining in any way where the thoracic and abdominal muscles are concerned, produces this effect. I think it is probable, that where there is a universal action of the vascular system, the action of the arteries and veins is alternate. That when the arteries contract, as in many fevers, the veins rather dilate, more especially the larger. [In order that the reader may perceive at one view the different relations in which the " circulation" may be viewed, I shall very briefly advert to the forces which are supposed to cooperate in this function. 1. The heart is undoubtedly the main agent of the circulation in all warm-blooded animals. According to Dr. Hales, the left ventricle ordinarily exerts a force of about 51-5 pounds, and propels the blood into the arteries with a force equivalent to about four pounds to each square inch of the arterial surface. The accuracy, however, of these deductions has lately been called in question by M. Poiseuille, and apparently with good reason. {Journ. de Phys., par Magendie, ix. 354.) 2. The arteries were regarded by Hunter as a sort of supplementary heart, scarcely less instrumental in the propulsion of the blood than the heart itself; although it is probable that in this estimate he was as much mistaken on the one hand as Dr. Arnott has lately been on the other in denying their agency altogether. (Elem.. of Physics, 5th edit., i. 555.) I shall not, however, enter here into the controverted question respecting the muscularity of the arteries, which appears to me to be a dispute about words rather than facts, for that the arteries possess a power of varying their calibre, quite independently of the force e tergo, is proved by the most indisputable facts (see p.'l60 et seq.). Admitting, therefore, the muscularity of the arteries as a fact, the question arises, in what manner is the circulation affected by it ? It is objected to the author's explanation of the action of the arteries, 1st, that if the arteries were extensively elastic, the intermittent stream in the arteries would soon be converted into a continuous one ; 2d, that no vermicular or progressive motion in the arteries has yet been observed; 3d, that no diametrical enlargement is visible in the living body; and 4th, that it is impossible to explain the almost perfect instantaneity of the pulse in all parts of the body, on the supposition that the tubes through which it is propagated are in a relaxed state. It is supposed, on the contrary, that the contractile fibres of the vessels operate at the same moment with the heart, so as to induce a rigidity of the whole arterial system, in order that the heart may produce 222 HUNTER ON THE BLOOD. its effect through all the vessels, almost as it would through tubes of metal. (Arnott ut supra.) Now the first of these objections does not aPPly» because such extensive elasticity as is supposed to exist does not occur, for even in the dead body the pulse may be imitated ; neither does the second objection apply much better, because the very assumption that the pulse depends on the transmission of a wave of blood, presupposes a certain interval of time, and consequently a progressive dilatation. The third objection has been adverted to already (see note, p. 210), to which I may add, that Poiseuille found, by direct and careful experiment, that the artery apparently dilated with each systole of the heart, that it reacted with a force superior to the impressing impulse, and that the arterial tension was nearly the same in all parts of the system at the same time. (Journ. de Phys., par Magendie, viii. 296. ix. 48, 50.) The fourth and last objection equally falls to the ground, when it is recollected that no such rigidity as is supposed to be necessary for the propagation of the pulse actually occurs, for the isochronism of the pulse is equally conspicuous in all states of the arterial tension, and is scarcely less remarkable in the dead body. When the heart contracts, a wave of blood is impelled into the arterial system, already full of blood, and the phenomena which immediately follow are, 1st, an onward motion of the whole column of blood; and 2d, a dilatation of the arteries in all directions, which dilatation can only take place at the expense of the force first exerted by the heart, but instantly reacts in the same proportion, so that no power is really lost, except what arises from friction, which is probably more than compensated for by the actively contractile properties of the arteries themselves. Now the rate at which a wave of blood is propagated is estimated at sixteen feet in a second, so that the contraction of the arterial system must be nearly instantaneous in all parts, although it must be apparent that the least deviation in this respect will be sufficient to give a vermicular character to the motion, and consequently a direction to the current. It seems probable therefore that the arteries do actually cooperate with the heart in propelling the blood, although I am disposed to regard this effect rather as incidental than as one of the primary objects for which muscularity was introduced into the arterial structure. The primary objects seem to be, 1st, to enable the arteries to accommodate their capacity to the varying quantities of blood in the system ; 2d, to modify the velocity and quantity of blood sent to individual parts, without engaging the whole system in this act; and 3d, to secure the temporary arrest of hemorrhage. 3. Adjacent muscular contraction can only operate on that portion of the blood which has already passed the principal bar of the capillary circulation. It must materially lend, however, to accelerate the blood during active exercise, although it has probably little effect on the ordinary circulation. The alternate action and relaxation of the abdominal muscles in ordinary respiration will be attended with a similar effect. 4. The pulsation of the arteries against the adjoining veins must ultimately be referred to the force of the heart. Inconsiderable as this agency may appear, it is certainly deserving of being taken into account, for when we reflect on the force with which the foot is raised when one leg is laid in rest over the other, we may see how the same force, counteracted by the elastic tension of the skin, and thus brought to operate on OF THE VASCULAR SYSTEM. 223 the venous circulation, may have considerable effect; not to mention the fact that large arteries and veins are often bound together in a common sheath of fascia. 5. The pressure of the external air has been a good deal insisted on. A tendency to form a vacuum in the chest has been supposed to arise from four causes: 1, the active dilatation of the right auricle and ventricle ; 2, the contraction of the ventricles ; 3, the resiliency of the lungs ; and 4, the enlargement of the chest during inspiration. Without, however, entering into the specific objections which may be urged against each of these views separately, I shall merely observe, in general, that the circulation goes on with quite as much celerity in the foetus in utero as in the adult; that it goes on in birds, turtles, cetacea, &c, in which the lungs are adherent to the chest, and in fishes in which there are no lungs at all; and finally, that it goes on in artificial respiration, when the heart and chest are fairly exposed, as well as in persons who voluntarily hold their breath. Nothing, indeed, can be conceived less adapted for the office of a pump than the whole aspect of the venous system, which would infallibly collapse if any considerable external pressure was exerted upon it. It is probable that the utmost sugescent power of any of these causes, or all of them combined, in ordinary respiration, is not sufficient to raise a column of blood of a single inch (Arnott, p. 572) ; for although the force e tergo soon raises the tension of a vein on which a ligature has been placed nearly to the same degree as that of the arteries, yet the suction on the near side of the ligature is not sufficient to empty this portion of the vessel, provided it lies ever so little below the horizontal plane of the heart. Poiseuille, in his experiments, found, that even in the arteries the flow of blood was sometimes entirely arrested during forced inspiration, and accelerated in the same proportion during expiration (op. cit., viii. 298); effects which are still more visible in the great veins in the immediate vicinity of the chest, as well as in those of the brain and spinal marrow, from these vessels, which are destitute of valves, allowing a regurgitation of blood : nothing, however, is gained to the circulation by this means, for one effect is exactly balanced by the other, the sugescent and repellent influences being exactly correspondent. 6. Gravity. The arch of the aorta rising several inches above the entrance of the vena cava inferior into the auricle, the gravitating pressure of the descending column of blood in the arteries will of course be sufficient to lift the ascending column in the veins several inches beyond what is actually required. The reason that the tension of the veins is not equal to that in the arteries is that the blood in the former finds a ready escape into the auricle, so that unless some obstruction is found in the auricle, the venous tension can never exceed that which will be required simply to lift the column of blood to the heart, added to that required to overcome the friction. Dr. Hales found, that although the column of blood from the carotid artery of a horse rose ten feet in his experimental tube, the venous column did not exceed six inches ; but " when from agitation of the animal, or any straining exertion, the passage of the blood into the breast was impeded, ail the veins became tense, and a tube inserted into the returning jugular had blood running over, at a height of three feet above the heart." A similar increase of tension is shown in common venesection, so that the first jet of blood is often found to ascend to the top of a lofty bedstead, although a minute afterwards the stream 224 HUNTER ON THE BLOOD. may not project a single foot. Poiseuille found that the arterial tension of the carotid of a dog was just doubled when the aorta and its primary branches were previously tied. 7. The Capillaries. It was Bichat's opinion that the influence of the heart did not extend beyond these vessels, but that "dans le systeme capillaire generate la contractilite insensible ou la tonicite reste seul pour cause de mouvement du sang ;" and certainly, if we admit ever so little force to reside in this system, the extent of it is so great that the aggregate force of the whole would amount to something very considerable. I shall not do more than simply refer to plants, sponges, medusa?, entozoa, and many of the lower tribes of animals, in which the circulation of the nutritive fluids seems entirely to be dependent on the force of the capillaries; but as we ascend the animal series we still observe the influence of this system, the heart seeming to be, as in fishes, rather an appendage to respiration, to insure the regularity of this function, than necessary to the general circulation. Hunter has remarked that the heart is proportionally small wherever the arteries are endowed with great muscular powers, examples of which may be found in foetuses and hybernating animals; in both of which there is comparatively great tenacity of life, joined to an unusual development of the cutaneous capillary circulation. In the foetus a double circulation is to be maintained through the placenta and the system, although the heart is found to be proportionally small as compared with the whole mass of blood, at the same time that it is placed under such circumstances that it cannot possibly receive any assistance from suction or muscular motion. Another series of proofs is derived from diseases and malformations of the heart and great arteries. In many of these examples (See Otto's compend. of Path. Anat., pp. 262—269, and Meckel's Man. d'Anat., ii. 109, 292), it seems impossible to consider the heart as the prime agent of the circulation ; not to mention that the foetus has occasionally attained its full growth in the womb, and even lived for some days after expulsion, where not the smallest rudiment of a heart has been observable. (See Brodie in Phil. Tr. 1809, p. 161.) Now, as there is no pulsation in the vena cava of adults, in the trunk of the lymphatic system, nor in the aorta of fishes, but the fluid in these vessels is entirely propelled by the force e tergo, it seems reasonable to infer that probably the same principle operates in the foetus, and that the organization in fact follows more or less the inferior type where the capillary circulation is totally independent of a central organ. Many facts, however, might be stated which seem directly to prove the independent action of the capillaries : 1. The derivation of blood into the collateral cutaneous capillaries, and the increased warmth which ensues thereupon, in cases where a ligature has been placed on the main artery of a limb. 2. The united force of the capillaries, as evinced in the raising of the toe when one leg is placed over the other, as contrasted with the small force required to stop the current of blood in any large artery, seems only explicable on this principle. 3. Blushing, and partial determinations of blood in health and disease. In fevers the heart is observed to act with great energy at the same time that the whole capillary system is proportionably contracted, while, on the other hand, local determinations and excitements are perfectly compatible with a feeble action of their viscus. No fixed relation, in short, seems to exist between the activity of the OF THE VASCULAR SYSTEM. 225 central organ and the peripheral circulation. 4. Nearly allied to this is the derivation of blood to a wounded vessel or part after the extraction of the heart; and the generation, as it were, of new vessels capable of admitting red blood. 5. The liability of the capillary circulation to be retarded or entirely stopped by causes operating on the nervous system, notwithstanding that the heart's action continues unabated ; for it must be evident that the power which can resist the impulse of the heart at one time, may assist it at another. 6. The different velocities of the blood in the same series of capillaries, and the liability of these velocities to be reversed from slight causes, is sufficient proof of the power of these vessels to control the local circulation. 7. The power of the capillaries to carry on the local circulation after the removal of the heart has been attested by numerous observers. Guillot remarked it in the frog's foot, when separated from the body, for nearly half an hour, ( Journ. de Phys., par Magendie, xi. 170,) although the progression of the blood in such cases has generally been observed to be very irregular. 8. Hence the vacuity of the arterial system after death, and the gorged state of the veins ; and hence also the disappearance of the blush of inflammation after death ; but in deaths from lightning the arterial system is found full of blood, contrary to what generally happens ; for the cause of death being such as to destroy the tonicity of the vessels, the capillary tubes are now no longer able to pump the blood from one system of vessels into the other. In asphyxia the right ventricle continues to act vigorously for some time after apparent death, although it is unable to propel its contents forward through the pulmonary capillaries, in consequence of these vessels being paralysed by the black blood (see note, p. 157). 9. The experiments of Hunter and Wedemeyer before mentioned can only be explained on this hypothesis (p. 157)-; and, lastly, the analogy which arises from the foregoing phenomena, that the blood when it gets into the capillary structure falls more or less under the dominion of those laws which regulate the circulation of the inferior animals. The inference which may fairly be drawn from the whole of these facts seems to be that the capillaries possess a distributive power over the blood, so as at least to regulate the local circulation independently of the central organ, in obedience to the necessities of each part. In the lower animals a slow circulation only of the blood is required, because the respiratory organs being here distributed over the whole body, and the systems of black and red blood being imperfectly preserved, a rapid circulation would answer no object: here, therefore, the capillaries suffice. In proportion, however, as the respiratory organs become more centralized so does the distinction between the two bloods become more definite and the necessity for arterial blood more imperative; so that here a heart becomes necessary, in order that the blood may be subjected to the influence of the air in a complete manner, and be supplied with due rapidity to the different organs of the body. It is possible that the capillaries may possess a propellent as well as a distributive power, and thus vicariously assist the heart under certain circumstances. I do not think it probable, however, that they concur to any great extent in the ordinary circulation. 8. Vital attractions and repulsions, existing either between the vessels and their contained fluids, or else between the different particles of the fluids themselves, is another agency to which many of the preceding phenomena have been ascribed. The following are the grounds for this opinion: 1. The capillaries appear as mere inert tubes under the 20 226 HUNTER ON THE BLOOD. microscope. 2. A determinate circulation or cyclosis is carried on in the parenchyma of many animals and vegetables where no vessels exist. 3. A similar phenomenon is observed in the first days of embryonic life, the vessels being a result or consequence of these motions ; and, lastly, the globules possess an inherent power of self-motion (see notes, pp. 68. 130), in virtue of which they move in determinate directions, agglomerate together in piles or rouleaux, traverse the substance of recently deposited lymph, ascend against the force of gravity when effused on the surfaces of living membranes, escape from the blood-vessels into the parenchyma of the surrounding textures, &c, &c. (Haller, Bollinger, Ge?idrin, Rayer- Collard, Kaltenbrunner, and Marshall Hall.) These attractions and repulsions are supposed by some to resemble the attractions and repulsions of similar particles united so as to compose muscular fibre, and by others to depend on the different electrical relations induced by respiration and nutrition altering the chemical constitution of the blood. Thus, according to this principle, attraction is supposed to draw the blood to a part being in action, and repulsion to drive it from it, and this in exact proportion to the energy of the action going on in that part; so that instead of the increased circulation being, as is commonly supposed, the cause of the increased action, the very reverse is the case. The vital action induced in a branch of a tree exclusively exposed to the sun, is the cause and not the effect of an increased flow of sap into it. (See Alison's Physiology, p. 32, and Supp., p. 25.) 9. Endosmose und Exosmose.—Attempts have been made to refer the circulation of the blood to these sources, but it is difficult to conceive how such causes can give a determinate direction to the circulating fluids, or how the circulation thus carried on can be affected by physiological causes. (See RaspaiVs Organic Chemistry, tr. by Dr. Henderson, p. 400.) BIBLIOGRAPHY OF THE VASCULAR SYSTEM.*

Adye, R. (Th.) De Sang. Circ. viribusque eundem facientibus. 1778. ----Albinus, B. S. Acad. Adnot. 1754. 1. iv. c. 8. De Arteria? Meinb. et Vasis.----Alderson, J., M.D. Quart. Journ., xviii. 223. Remarks on the Beating of the Heart.----* Alison, loc. cit. and Fourth Rep. of Brit. Assoc, p. 674. On the Contractile Power of Arteries leading to Inflamed Parts.----Andral. I. c.----Araldi, M. Mem. delle Soc. Ital. (1804.) xi. 342. 383. (1810.) xv. 166. 196. Delia Forza e dell' Influsso del Cuore sul Circolo del Sangue.----*Arnott, N., M.D. Elements of Physics. 5th edit. 1833. p. 543.

Batr, C. E. a De Ovi Mamm. et Hominis genesi. 1828.----Barclay, J., M.D. A Descrip. of the Arteries. 1812.----Baron. Bulletin des Sc. Med. ii. 169. L'Usage des Anastomoses.----Barry, Sir David Rech. Exp. sur les Causes de Mouvement du Sang dans les Veins. 1825. and Transl. 1826.----Bassuel, C. Mem. de Math, et de Phys. (1750.) i. 22-55. Diss. Hyd.-Anat. des Arteres.----Beclard. Mem. des la Soc. Med. d'Emul. (1817.) viii. Sur les Blessures des Arteres.

* See p. 138 for the explanation of the star and for the titles of those works which are here merely referred to. BIBLIOGRAPHY OF THE VASCULAR SYSTEM. 227 ----Behrends, J. Diss, qua demonstratur Cor Nervis carere, addita Disquis. de Vi Nervorum Arterias cingentium. 1792.----Bell, Sir C. An Essay on the Forces which circulate the Blood. 1819____Bellieri, L. De Urinis et Pulsibus, &c. 1698; et Opuscula. 1714. De Motu Cordis.---Belmas, D. Sur la Structure des Arteres, &c. 1822. ----Berdoe, 1. c.----Berlin, J. E. Quaestio Med., An Causa Motus alterni Cordis multiplex? 1740. (Haller. Disp. Anat. ii. 429.)---- Bertin, R. T. and Bouillaud, J. Traite des Maladies du Coeur, &c. 1824.----Bernouilli.—See Passavant.----Berzelius, J. O. A View of the Prog, of Anim. Chem. tr. by G. Brunnmark. 1813. pp. 24, 25. On the Chem. Constitution of the Arter. Tunics.----*Bichat. 1. c. ----Black, J., M.D. On the Capill. Circ, &c. 1825.----Blancardi, S. Anat. Pract., &c. accedit item tractatus de Circ. Sang. &c. 1688. ----Bordeu, T. Rech. sur le Pouls, &c. (ou QSuvres Comp. 1818. i.) 1754.----Bourdon, Is. Rech. sur le Mechan. de la Respir. et sur la Circ. du Sang. 1820.----Borelli. 1. c.----Breckelmann, M. L. R. De Nervorum in Arleriis Imperio Dissert. 1744. (Haller. Disp. Anat. iv. 425.)----*Brodie, Sir Benj. Phil. Trans. 1809. p. 161. Account of a Dissect, of a Human Foetus in which the Circ. was carried on without a Heart.—ib. 1811. p. 36. On the Influence of the Brain on the Action of the Heart.----Bosch, H. Van den. Theor. und Prakt. Bemerkenger uber das Muskelvermogen der Haargefaschench. 1792.----Breschet. Rech. Phys. et Path, sur le Systeme veineuse. 1819.----Broussais, F. J. V. Mem. de la Soc. Med. d'Emul. vii. 1. and Ann. de la Soc. de Med. de Montp. xx. 195. Sur la Circ. Capillair.----Brown, R. Phil. Mag. et Ann. of Phil., Sep. 1828. p. 161. Micros. Obs. on the Self-movement of organic and inorganic Molecules.----Buniva. Recueil period, de la Soc. de Med. vii. 110. Exp. sur les Injections dans l'Anim. viv. et dans le Cadavre.----* Burdach, I. c. ■ Burns, A. On the Diseases of the Heart. 1809.

Carlile, H. Third Report of Br. Association (1834), p. 454. Observ. on the Motions and Sounds of the Heart.----Carlisle, Sir A., Phil. Tr. 1805. p. 1. Croonian Lecture on Muscular Motion.—ib. 1800. p. 98; 1804. p. 17; and 1806. p. I. On a Peculiarity in the Distrib. of the Arter. of slow-moving Animals.----*Carson, J., M.D. An Inquiry into the Causes of the Motion of the Blood, &c. 1815.----*Carus, CE. G. Lehrbuch der Zootomie, tr. Fr. by A. J. L. Jourdan,2eme edit. 1835. ii. 298. Systeme Vasculaire, and tr. Eng. by R. T. Gore. ii. 263.---- Chirac, P. De Motu Cordis, &c. 1698.----Chassaignac, E. De la Circulation Veineuse.----Clark, W., M.D. Fourth Report of Br. Association (1835), pp. 95, 129. Report on Animal Physiology, comprising a Review of the Blood and Powers of Circulation.----Clift, W. Phil. Tr. 1815. p. 91. On the Influence of the Spinal Marrow on the Action of the Heart.----Cloquet, J. De l'lnfluence des Efforts sur les Organes dans la Cavite thoracique. 1820.----Corvisart, J. N. Sur les Maladies du Coeur, &c, Seme edit. 1818, and tr. by C. H. Hebb. 1813.----Coxe, R. An Inquiry into the Claims of Dr. William Harvey to the Discovery of the Circulation of the Blood, &c. 1834.---- Cranen, T. OZJcon. Anim. ad Circ. Sang., &c. 1703.----*Cuvier, le Baron, G. Lecons d'Anat. Comp. an vii-xv. and Le Regne Animal. 1829. 228 HUNTER ON THE BLOOD. Dennison, R., M.D. Disp. Inaug. Arter. omnes et Venarum Partem Irritabilitate praeditas esse, (in Smellie's Thes. Med. iii. 394.) 1775.---- *Dollinger. 1. c. et Journ. des Prog, des Sc. Med. ix. Sur la Circ. Capill____Dutrochet, H. Rech. Anat. et Phys. sur la Struct, intime des Anim. et des Veg. et sur leur Motilite. 1824.—De 1'Agent immediat de Mouvement Vital. 1826; and Ann. des Sc. Nat. xv.

Ehrmann, C. H. Struct, des Arteres et leur Proprietes et leurs Fonctions, &c. 1822.----Ens, A. (Th.) De Causa Vices Cordis alternas producente. 1745. (Haller. Disp. Anat. ii. 409.)----Entius, G. Apol. pro Circ. Sang. 1689.

Falconer, TV., M.D. Observ. respecting the Pulse. 1706.----Fischer, Dissertatio de Motu Sanguinis, 1720.----Floerckius, G. (Th.) Transitum Sang, per Vasa minima, &c. 1713.----Flourens, P. Rech. sur les Fonctions du Syst. Nerveux dans les Animaux vertebres, 1824-5 ; and Supplement du precedent, 1825; and Mem. de lTnstitut, tom. x. ----Formay J. L. Versuch einer Wurdigung der Pulsen. 1823.---- Fouquet, H. Sur le Pouls (nouv. edit.) 1818.

Gardien. Bull, du Sc. Med. iv. 31. Sur la Circ. Capill.----Gayant. L. Mem. de Paris, i. p. 36. Obs. sur les Valv. des Veines.----Gendrin, 1. c.----Gerdy, S. JV". Sur l'organ. du Coeur. dans le Journ. Comp. du Die. des Sc. Med.----Giulo et Rossi. Mem. de l'Acad. de Sc. de Turin, iv. 50. Dissert, de Excitabilitate Contract. Vi. Partibus Muse. ope. Elect.----Glass, C. P. De Sang. Circ. 1736. (Haller. Disp. Anat. ii. 201.)----Grant. 1. c. et Edin. Phil. Journ. xiii. and xiv. ----Gruner, C. J. Semiotice Phys. et Pathol. 1775.----Guillot, X. Journ. de Phys. par Magendie. (1831.) xi. 145. Obs. sur quelques Phenom. de la Circ.

*Hales, G., D.D. Statical Essays. 4th edit. 1767.----*Hall, M., M.D. On the Circul. of the Blood. 1831.----^Haller, A. 1. c. et Mem. sur la Nat. Sens, et Irrit. de3 Parties. 1756. § xi.—Opera Minora, i. 60- 241. Sur la Circul. Capill.—Sur la Formation du Coeur dans le Poulet, &c. 1758.----Com. Soc. Gotting. i. 263. Exp. de Cordis Motu; and ib. iv. 396. De Sang. Motu Exp. anat.----Harrison, R. On the Surgical Anat. of the Arteries. 1824-5.----*Harvey, G. De Cordis et Sang. Motu. 1648.----'Hustings, C, M.D. On Inflam. of the Mucous Mem. of the Lungs, with Exp. Inquiries respecting the contractile power of the blood-vessels in Inflam. 1820.----Hebenstriet, J. S. De Vaginis Vasorum. 1710.----Heberden, TV., M.D. Med. Trans, ii. 18. Remarks on the Pulse.----Hering, Prof. Zeitschrift fur Physiologie, iii. and iv. part 1.—Journ. de Prog, des Sc. Med. x. et Med. Gaz. (1834). xiv. 745. Exp. tending to show the Rapidity of the Circ.---- Hewson. 1. c.----Hodgson. 1. c.----Home, Sir E. Lect. on Comp. Anat. 1814. p. 47. On the Median, of the Heart.----Hope, J., M.D, On the Diseases of the Heart, comprising a new View of the Physiology of the Heart's Action. 1832.----Housset. Mem. sur les Parties irrit. et sens. ii. 404.----Humboldt, F. A. Exp. sur lTrrit. des Fibres Muse, &c. tr. from the German by J. F. Jadelot. 1799.----Hunt, J. Obs. on the Circ. of the Blood, &c. 1787. BIBLIOGRAPHY OF THE VASCULAR SYSTEM. 229 *Jones, T. F. On the Process employed by Nature in suppressing Hemorrhage. 1805.----Jurin, J. Phil. Trans. 1718. p. 863; 1719, pp. 929. 1039. Diss, de Potentia Cordis.

*Kaltenbrunner. 1. c.----Keill, J. Tentam. Med.-Phy. de Velocitate Sanguinis. 1718. and Phil. Tr. 1719. p. 995.----Kerr, G. Obs. on the Harveian Doct. of the Circ. of the Blood. 1819.----Konrad, G. V. De Arter. Fabrica. 1814.----Kramp, C. De Vi vitali Arteriarum, &c. 1785-8.----Kreysig. Ueber die Herzkrankheiten. 1814.

Laennec, R. T. H. De I'Auscult. Mediate. 3eme edit. 1831. pp. 195, 445. tr. by J. Forbes, M.D. 4th edit. 1834. On the Action of the Heart.----Lamure, F. Mem. de Paris, 1749. p. 541 ; and 1765. p. 620. Rech. sur la Cause de la Pouls des Arteres.----Lancisi. 1. c. ----Langelott, A. C. De Fabrica et Usu Cordis. 1676.----Lassbne. Mem. de Paris, 1756. p. 41. Rech. sur la Struct, des Arteres.---- Leeuwenhoeck. 1. c.----Le Gallois. 1. c. et Exp. sur le Principe de la Vie. 1812.—Nouv. Bull, de la Soc. Philom. (1812.) iii. 5. Sur la Force du Coeur ; etRecueil period, de la Soc. de Med. xxxv. Paog. des 425.----* Leuret. Journ. des. Sc. Med. v. Sur la Circ. Capill.---- Lister. Phil. Tr. 1834. p. 365. Obs. on the Struct, and Func. of tubular and cellular Polypi, showing the mode of circ. in these animals.---- Lorry. Savans Etrangers. (1752.) iii.----Lower, R., M.D. Tractatus de Corde. 1728.----Luca, S. E., M.D. Quaedam Obs. Anat. circa Nervos, Arterias adeuntes et comitantes. 1810.----Ludwig, C. G. (Th.) De Arter. Tunicis. 1739. (Haller. Disp. Anat. ii. i.) *Magendie. 1. c. et Journ. de Phys. (1821.) i. 97. 102. 132. and 190. Sur la Circ. et sur I'Action des Arteres dans la Circ.; and Lect. on the Circ. in Lancet, 1834-5. i. 310. et seq.----Malpighi. 1. c.----Martin- Saint-Ange. Anatomie Analytique : Circulation du Sang, consideree chez le foetus de l'homme, et comparativementdes quatre classes d'animaux vertebres. 1833.----Marx, H. Diatribe Anat-Phys. de Structura atque Vita Venarum. 1819.----Mauban, R. Ess. sur la Cir. 1808.---- Mayo, H. 1. c. and Anat and Phys. Coram. 1822-3. p. 16____Mayer, J. C. A. Anatomische Beschreibung der Blutgefasse des menschlichen Korpers. 1777-8. et Edit. 2de. 178$.^-Meckel, J. F. Joivrn. Comp. du Die. des Sc. Med., i. 259. Sur le Developpment du Coeur, et Man. d'Anat. Gen. tr. by A. L. Jourdan et G. Breschet. 1825. i. 125. Du Systeme Vasculaire.----My en, 1. c.----Mondini. De Arteriarum Tunicis, in Opuscoli, &o. 1817.—■—Moulin A. e.----Munro, A. (Prim.) Edin. Med. Ess. and Obs. ii. 264. Remarks on the Coats of Arteries. ----Murray, A. Descrip. Arteriarum. 1783-98.

Nicolaus, H. A. De Directione Vasorum pro modificando Sang. Circ. 1725. (Haller. Disp. Anat., ii. 481.)----Nysten. I.e. et Nouv. Rech. Galv. sur les Org. musculaires, &c. An. xi.

Paletta, J. B. Mem. dell. Instit. Ital., i. 34. Del Memento retrog. de Sangue.----Parry, C. H, M.D. On the Arterial Pulse. 1816; and Add. Exp. 1819.----Passavant, D. (Th.) De Vi Cordis. 1748. (Haller. Disp. Anat., vii. 329.)----Pasta, A. De Motu Sang, post Mortem, &c. 1786.----Pechlin, J. N. De Fabrica et Usu Cordis. 1676.---- Pelletan. Clin. Chir. 1810. iii. Sur le Coeur.----*Philip, A, P. TV,, 230 HUNTER ON THE BLOOD. M.D. Exper. Inquiry into the Laws of the Vital Functions. 2d edit. 1818; and Phil. Tr. 1815. pp. 65, 424. On the Relations between the Nervous and Sanguiferous Systems.—See also Treatise on Sympt. Fevers. 4th edit. 1820. pp. 15, 17. ; et Med. and Chir. Tr., xn. 401. On the Circulation, and particularly the Capillary.----Piorry, P. A. De l'Explor. des Organes par la Percussion, and Collect, de Mem. sur la Phys. 1831. 3eme. Sur la Circ.----Pie. 1. c.----*Poiseuille, J. L. M. Journ. de Phys. par Magendie, (1828.) viii. 273. (1829.) ix. 341. Sur la Force du Cmur aortique: ib. p. 44. Sur l'Action des Arteres dans la Circ. arterielle :—ib. (1830.) x. 277. Rech. sur la Cause du Mouvement du Sang dans les Veins.----Portal, A. L'Anat. Med. 1804. iii. 72; and Mem. de Paris. 1770. pp. 42, 244.---- Posewitz, J. F. S. Phys. der Pulsadem des menschlichen Korpers. * 1795.----Prevost and Dumas. Ann. des Sc. Nat. iii. 46. Developpement du Coeur et Formation du Sang.—See also tom. xii.----Prochaska. 1. c. Raspail. 1. c. et Bull, des Sc. Nat. xii. 193.----Rayer-Collard. Essai d'une Syst. de Zoonom., p. 80.----Regis, J. C. De Sang, in suo per vasa progressu, &c. (Haller. Disp. Anat., ii. 595.)----Reichel. 1. c. ----Reisel, S. Misc. Acad. Nat. Cur. 1673-4. p. 245. 1678. p. 91. 1682. p. 448. De Circul.----Rezia, J. De Ratione Sang. Motus in Arterias. (Rsemer. Dissert. Med. Ital.)----Richelmann, J. E. De Valvularum, &e. 1683.----Richerand. 1. c. et Mem de la Soc. d'Emul. an iii. 296.-——Riolan, J. De Motu Cordis et ejus Circ. 1652.---- Rolando. Journ. Comp. du Die. des Sc. Med., xv. 323. xvi. 34. Sur la Formation du Coeur et des Vaisseaux, &c.----Rose, L. G. 1. c. Sabatier, R. B. Traite d'Anat. 3eme edit. 1791. iii.; and Mem. de Paris. 1774. p. 51. Sur la Circ. du Sang du Foetus et sur la Capacite du Coeur.----Santorini, J. D. Obs. Anat. 1724. cap. viii. De ii3 qua? in Thoracem sunt.----Sauvages, F. L. B. Mem. de Montp. ii. 140. 211. Theorie du Pouls and Mem. de Berlin. 1755. p. 34. Rech. sur les Loix du Mouvement du Sang.----Scarpa, A. Tabula? Neurol, adillust. Hist. Anat. Cardiacorum Nervorum. 1794.----Schedel, F. J. Physiologia Pulsus. 1829.----Schliting. Savans Etrangers, i.----Schmidt, D. fV. (Th.) De Motu Sanguinis per Cor. 1737. (Haller. Disp. Anat., ii. 391.) ----*Schultz, K. H. 1. c. et. Journ. Comp. du Die. des Sc. Med., xix.----*Senao. 1. c.----Sharpey. Edin. Med. and Surg. Journ. xxxiv.----Smith. 1. c.----Spal/anzani, Z. Exp. sur la Circ, <fcc. tr. par D. M. M.Tourdes. An. viii.----*Soemmerring, S. T. De Corp. hum. Fabrica. 1794-1801. v. Angiologia, and Lehre vom Barre des menschlichen Korpers, iv.----Soutien, G. Rec. period, de la Soc. de Sante de Paris, iii. 402. Sur la Circul____Sprengel, K. Beitrage zur Geschichte der Pulsen. 1787.----Storer. Trans, of a Soc. for the improvement of Med. and Chir. Knowledge. 1812. On the Want of Pulsation in paralytic Limbs.----Swieten, S. Van. (Th.) De Arteria? Fabrica, <fec. 1725.

Testa, A. J. Delle Malattie del Cuore. 1810-3.----Thomson, J. 1. c. -----*Tiedemann, F. 1. c. et Tabulae Arteriarum 1822-4.----Treviranus. Erscheinungen, 1. c.----Turner, T. On the Arterial system. 1835----Tyssot, P. F. De Circ. Sang. 1743. UNION BY THE FIRST INTENTION. 231 Vaust, J. F. Rech. sur le Struct, et les Mouvemens du Coeur. 1821.____ *Vershuir, G. De Arteriarum et Ven. Vi irritabili, &c 1766.____ Vieussens. 1. c. et Novum. Vasorum Corporis hum. Systema. 1705; and Traite de la Struct, etdu Mouvement du Coeur. 1711.

Walter, F. A. Angiologisches Handbuch. 1789.----*Wedemeyer. 1. c. et Edin. Med. and Surg. Journ., xxxii. 10; and xxxiv, 89----Weitbrecht,J. Com. Acad. Petrop., vi. 276. vii. 2£ 3. viii. 334. De Cir. Sanguinis----Whytt. 1. c.----Wilson, A., M. D. On the Circul. of the Blood. 1774.----Winslow, W. Mem. de Paris. 1711. pp. 196, 201. Sur le Coeur.----*Wintringham, C, M. D. An Inquiry into the Exility of the Vessels of the Human Body. 1743 ; or Works. 1752.----*Wolff, C. F. Acta Acad. Petrop. 1780-7; et Nova Acta, i. and viii. Dissert. Octonoven de Cordis Fibris.----Wrisberg, H. A. De Nervis Arterias Venasque comitantes. 1800.

*Voung. 1. c. et Phil. Tr. 1808. p. 164. Hydraulic Investigations concerning the Motion of the Blood.—1809. p. 1. On the Functions of the Heart and Arteries.

Zerrener, A. T. X. An Cor Nervis careatet iis carere possit ? 1794.---- Zimmermann, J. G. Diss. Phys. de Irritabilitate. 1751 ; and Das Leben des Herm von Haller, 1755.----Zugenbuhler. Dis. de Motu San. 1815.

N. B. For the Pathology of the Vascular System consult Otto's Compendium of Path. Anat. tr. by /. F. South. 1831- § xix. ; PloucqueVs Repertorium Medicina? Practicae. 1808-9; and Reuss's Repertorium Commentationum a Socictalibus Literariis. 1801-13. torn- x. and xii- PART II. CHAPTER I.

UNION BY THE FIRST LNTENTION.

I may observe, that all alterations in the natural dispositions of a body are the result either of injury or disease; and that all deviations from its natural actions arises from a new disposition being formed.* Injury is commonly simple ; disease more complicated.

* [This observation is probably correct as far as regards injuries, which necessitate a new disposition, and consequently new actions, in order to repair the injury. But with regard to disease, it is, I think, manifestly wrong. Disease is a disordered state of action of the living parts, which must have been preceded by a disposition to such state of action. How, then, can such an alteration in the disposition be considered as the result of disease 1 It should rather be, all altera- 232 HUNTER ON THE BLOOD. The dispositions arising from these are of three kinds : the first is the disposition of restoration, in consequence of some immediate mischief, and is the most simple. The second is the disposition arising from necessity; as, for instance, that which produces the action of thickening parts, of ulceration, &c. This is a little more complicated than the former, as it may arise both from accident and disease, and therefore becomes a compound of the two. The third is the disposition in consequence of disease; which is more complicated than either, as diseases are infinite. Yet many local diseases, although complex in their natures, are so simple in their extent as to allow the removal of the diseased part; becoming, when that is done, similar to many accidents.* As disease is a wrong action of the living parts, the restoration to health must first consist in stopping the diseased dispositions and actions, and then in a retrogade motion towards health. In treating systematically of such complaints as are the objects of surgery, we should always begin with the most simple, and advance gradually to the more complicated, by which means we shall be more clearly understood. There are many complaints requiring the attention of the surgeon which cannot be called disease; because, having been produced by something foreign to the body, as in accidents, they are to be considered as a violence committed upon it, altering in some degree the structure of parts, and consequently interrupting the natural operations already described. The parts so hurt not being able to pursue their original or natural mode of action, are obliged to deviate from it; and this deviation will vary according [1] to the nature of the violence, [2] the nature of the part, and [3] the state of the constitution at the time. An alteration in structure requires a new mode of action for its restoration : as the act of restoration cannot be the same with what was natural to the parts before any alteration had taken place. The alteration of structure by violence requires only the most simple change in the natural action of the part to restore it, and of course the most simple method of treatment by art, if it be such as to require any assistance at all; for there are many accidents where none is necessary. It will be proper to observe here that there is a circumstance attending accidental injury which does not belong to disease, viz., that the injury done has in all cases a tendency to produce both the disposition and the means of cure. The operations of restoration arise naturally out of the accident itself; for, when there is only a mechanical alteration in the structure,

tions in the natural dispositions of the body are the result of injury or some other cause tending to disorder them.] * [It would probably have been better to have divided these dispositions into two kinds, viz., healthy, and unhealthy. The temporary thickening of the parts in the union of fractured bones and numberless other processes is asmuch a restorative action as union by the first intention, not to mention that this last action is invariably attended with some degree of thickening of the parts.] UNION BY THE FIRST INTENTION. 233 the stimulus of imperfection taking place immediately calls forth the action of restoration. But this is contrary to what happens in disease ; for disease is a disposition producing a wrong action, and it must continue this wrong action till the disposition is stopped or wears itself out. When this salutary effect, however, has once taken place, the state of the body becomes similar to that in a simple accident, viz., a conciousness of imperfection is excited which produces the action of restoration. In injuries arising from accident we have hitherto supposed that the parts have no tendency to any diseased action independently of the accident, for if they have, it is probable that such a tendency may be stronger than the disposition for restoration, and in that case they will fall into the peculiar diseased action, as was explained when treating of susceptibility. Let us take the scrofula and the cancer as examples, and we shall find, that if a part be hurt which has a strong tendency to scrofula, it will most probably run into the scrofulous mode of action in preference to that of restoration, and therefore we have many joints, when injured, assuming the scrofulous action, called white swelling; or if a woman beyond thirty years of age receives a blow on the breast, it is more likely to acquire the cancerous mode of action than that of restoration, which should be well distinguished from what is immediately consequent, viz., the inflammation; for on this depends a knowledge of diseases. Although accident may be said to produce an effect on a part (whatever that effect may be), which has a tendency to its own cure, yet there are often not only immediate consequences arising from that effect, as inflammation; and again, the consequences of this inflammation, as suppuration; but the bases of diseases are also frequently laid by it, not by producing them immediately or naturally, but by exciting some susceptibility of the constitution or of a part into a disposition for a disease which may be latent for a considerable time, and then come into action. Thus scrofula, cancer, &c, often arise from accident, even where the parts, in consequence of the injury, have gone through the immediate and the secondary stages of a cure. Those effects of accident which arise from the nature of the parts hurt may be divided into such as take place in sound parts, and such as affect parts already diseased. The first is what I shall at present treat of; the second, being connected with disease, is not to our present purpose. The injuries done to sound parts I shall divide into two sorts, according to the effects of the accident. The -first kind consists of those in which the injured parts do not communicate externally, as concussions of the whole body or of particular parts, strains, bruises, and simple fractures, either of bone or of tendon, which form a large division. The second consists of those which have an external communication, comprehending wounds of all kinds, and compound fractures. Bruises which have destroyed the life of the part may 234 HUNTER ON THE BLOOD. be considered as a third division, partaking, at the beginning, of the nature of the first, but finally terminating like the second.*

§ 1. Of Injuries in which there is no external Communication.

The injuries of the first division, in which the parts do not communicate externally, seldom inflame, while those of the second commonly both inflame and suppurate. The same operations, however, very often take place in both, though the order in which they happen is reversed, the first becoming like the second, by inflaming and suppurating, and the second being in many cases, when properly treated, brought back to a resemblance of the first, and united by the first intention, by which inflammation and suppuration are prevented. But when the life of a part has been destroyed by the accident, it must necessarily suppurate; and therefore these injuries will be rendered similar, in this respect, to those which communicate immediately, and have not been united by the first intention. That injury which in its nature is the most simple, and yet calls forth the actions of the part to recover from it, is a degree of concussion,! where the only effect produced is a debility of the actions or functions of the whole or part, similar to that occasioned by a bruise, in which the continuity of the substance is not interrupted: in such a state the parts have little to do but to expand and reinstate themselves in their natural position, actions, and feelings; and this is what happens in concussion of the brain.J The rupture of a small blood-vessel is, perhaps, the next in order of simplicity. Where the continuity of the part is broken, extravasation takes place, and the blood is diffused into the common cellular membrane, into the interstices of some part, or into a circumscribed cavity. But should the vessel be either very large, or essential to life, such as the femoral, brachial, or coronary arteries; or should the rupture take place in a vital part, as the brain, or into interstices or cavities belonging to a vital part, as into the cavities of the brain or pericardium, in all such cases the injury may kill from the extravasation alone, however inconsiderable may be the original mischief. The operation of restoration in this case, when the vital parts * [The greater violence of the inflammation succeeding to injuries which communicate externally may be a sufficient ground for the division of the text, although it should be remembered that the reparative processes are identically the same in both cases. Ruptured muscles and tendons, and many kinds of bruises, excite quite as much inflammation as clean incised wounds of the same parts. f Here I mean concussion as a general term, not confining it to the brain. X [Concussion of the brain is not unfrequently attended with an extravasation of blood in minute specks over an extended surface of the interior of the organ, as if arising from a rupture of a multitude of minute vessels. (See Brigkfs Medical Reports, vol. i. p. 405, and plates.) Probably some organic derangement takes place in all cases of concussion, although, from the extreme delicacy and minuteness of the ultimate structure, such changes are not always cognizable by our senses.] UNION BY THE FIRST INTENTION. 235 are not concerned or disturbed, consists, first, in the coagulation of the extravasated blood between the ruptured parts, laying, as it were, the foundation of union; next, in closing the ruptured vessel or in promoting its inosculation ; and some time after in bringing about an absorption of the superfluous extravasated blood. If the vessel close, that effect is produced by the muscular contraction of its coats; but in what way it inosculates, whether by the two orifices when opposed having a mutual attraction, and, instead of contracting the two portions of the ruptured vessel elongating, so as to approach each other reciprocally, and unite,* or whether by a new piece of vessel being formed in the intermediate coagulable lymph, is not easily determined.f Inosculation, however, can only take place where the extent of

* Inosculation is a term commonly used by writers, but whether it was derived from theory or observation is not material. The very few instances where it can be observed, together with the want of accuracy in those who first introduced the term, would incline me to think that it arose from theory or opinion only. I never could get an opportunity of observing it in all my experiments and observations on inflammation, except in the coats of the eye. In many inflammations of that organ we find an artery or arteries passing from the tunica conjunctiva to the cornea, and ramifying on that part. These have been often cut across to prevent the influx of blood; the two ends are seen to shrink, but in a little time they are again perceived to unite, and the circulation to be carried on as before. In this there can be no deception; and to perform, therefore, such an operation effectually a part of the vessel should be removed.11 j- [Arteries of considerable size are sometimes regenerated in the lower animals. Dr. Parry tied the cartoid artery of a young ram in two places, and removed two inches and a half of the intermediate portion, but in twenty-seven days the vessel was completely restored, so that scarcely any evidence appeared of the operation having been performed. In another case the right and left carotids of a young ram were tied with single ligatures, but the continuity of these arteries was also completely restored in the course of eight weeks, although not in so perfect a manner as in the former experiment. The process by which this is accomplished seems to be as follows. Coagulable lymph is first poured out by the inflamed vessels in the intermediate space between the two ligatures, which soon becomes organized, when a number of minute vessels may be observed extending in parallel lines between the two extremities of the artery, and thus making a communication between them. After a time one of these vessels is observed to enlarge, till at length it acquires the full size of the original vessel; but, in proportion as this takes place, the others dwindle away, and the superfluous lymph becomes absorbed. Such at least seems to be the process in brute animals where a portion of a large artery has been removed. I am not aware that anything similar has been observed in man.] * [Nothing certainly is known respecting the mode in which vessels inosculate. According to Professor Thomson, Mr. Hunter was deceived respecting the direct inosculation of the vessels of the sclerotic coat of the eye. " An attentive examination," he says, "of the phenomena will show that it is not the divided extremities that unite again, but the folds of small branches that are prolonged into the intermediate space, which become channels of communication between the larger trunks, which had been divided, but the extremities of which had been previously closed." (Lect. on Inflam., p. 213.) This account, however, does not appear to me to render the matter at all more clear.] 236 HUNTER ON THE BLOOD. the parts divided is not great, and the opposite surfaces remain near each other; but even then it is most probable that we must in part ascribe to another mode of union the communication of vessels which takes place between the two divided surfaces; for where inosculation does not or cannot take place, the union of the ruptured vessels is produced by the coagulation of the extravasated blood of this part, which becomes vascular. That the blood becomes vascular is clearly shown in the case of the blood extravasated on the testicle. [PI. I. and II. of Lectures on Principles of Surgery.] The superfluous extravasated blood is taken up by the absorbents, by which means the whole is reinstated as much as it is in the power of the parts to do it. I may observe here that the power of recovery in the arteries is greater nearly in proportion to the smallness of their size, which is combined with several causes, viz., their distance from the heart, their elasticity, their division into smaller branches, and their accumulated diameters becoming larger, which allows them to recover. Secondly, there is an increased power within the smaller artery itself, abstracted from the above circumstances.* This includes a great variety of cases, and the most simple difference which can happen between them will be owing to the magnitude of the ruptured parts, or to a difference in the parts themselves, or to the magnitude of the injury, or to a difference in the effects. It will comprehend simple fractures of all kinds, broken tendons, (as is often the case with the tendo-Achillis,) and even many injuries of the brain, producing extravasations of blood, which is probably the only way in which the brain can be torn when there is no fracture.f Some of these will often require art to reinstate them in the natural position, out of which they have been put by the accident, or by some peculiar circumstance attending the nature of the part, as we see in a fracture of the patella, or broken tendon, where the upper part being too far pulled up by the muscles, it must be reinstated by the hand of the surgeon, to bring the parts into a situation more favourable to their recovery. But extravasations, even from the most simple accidents, are often so situated as to obstruct the actions of life; as, for instance, in that affection of the brain which is called apoplexy. The same

* [The arteries become more muscular in proportion as the impetus of the blood becomes less powerful; both which circumstances must combine to render the obliteration of a bleeding vessel more effectual and speedy. Is this, however, the author's drift! or does he mean by " the power of recovery" that the small arteries which are " the formers and supporters of the body," or " the efficient part of the whole animal respecting itself," are capable of reinstating themselves after injury sooner than other parts! f Concussion of the brain may be in three degrees: 1. It may occasion an extensive rupture of the substance of the brain: 2. It may occasion rupture of the minute vessels only, giving rise to an effusion of blood from a multitude of minute points ; and, 3. It may only strain the organ, without'producing any visible rupture. These last cases, however, are not unfrequently fatal. See note, Prin. of Surg. p. 258.] UNION BY THE FIRST INTENTION. 237 thing happens in extravasations into the pericardium, or into any of the other vital parts, where little can be done although much is wanted. In many other parts, where the actions of life cannot be effected, yet the extravasations are often too considerable to allow the parts to go through their proper modes of restoration. The quantity of extravasated blood being often so large as to distend the parts, and form a kind of tumour called ecchymosis, of which I shall now treat. The extravasated blood in such cases being the only visible complaint, to remove it is the cure; which may be effected by absorption, or, if necessary, by an operation. An ecchymosis we may consider as of two kinds, one in which the blood coagulates when extravasated, the other where it remains fluid; but this distinction makes little difference in the disease itself, and of course little in the mode of treatment. It should be observed, however, that the first kind for the most part terminates well, while the second sometimes inflames and suppurates. When these injuries get well by the absorption of the blood, the cure is gradual, and often takes a considerable time; but if the tumours become less and do not inflame, they should be allowed tG go on to perform their own cure: and even where inflammation takes place, that should be permitted to advance to suppuration, and the tumours to threaten bursting before they are opened by art, or, what I believe would be still better practice, they should be left to open themselves altogether. In some instances, a blow, the cause of the ecchymosis, may have injured the superficial parts or skin so much as to produce inflammation ; and under such circumstances I should recommend the case to be treated as an inflammation arising from any other cause, without paying attention to the blood underneath. It often happens that the blow has deadened the skin over this blood, which deadened part, as is usual in such cases, must, in a certain time afterwards, separate from the living. Where this has taken place, and the extravasated blood has coagulated, it has often been found to remain in the cavity as a mere extraneous body, without acting, and without even allowing the stimulus of an exposed surface or of an imperfect cavity to take place. The edges of the skin all round showing the disposition to contract over this blood, as if it was a living part to be preserved, nothing has seemed to be wanting to finish the cure but the blood being alive with due powers of action. In these cases the common practice has been to scoop out the blood and distend the internal surface with warm dressings, to stimulate it to inflammation, &c.; and, a sore being the consequence of this method, it goes on as sores commonly do. But in other cases, where the opening leading to the coagulated blood has been very small, I have seen that, without any other means being used, the blood has been gradually squeezed out of the orifice by the contraction of the surrounding parts, till the whole cavity became so much contracted as to contain no more than what seemed to serve as a bond of union to the parts; and thus ihe cure has been com- 21 238 HUNTER ON THE BLOOD. pleted without further trouble. The following case was treated in this way. Mrs. B—t fell backwards and pitched upon a pail which was behind her, and the left labium pudendi struck against its handle with the whole weight of her body. Within five minutes after the accident the bruised part swelled to as great a degree as the skin would allow; from which sudden appearance of the swelling, and the feeling of fluctuation. I concluded that blood had been extravasated by the rupture of some small artery. I bled her, and desired a poultice to be applied to the part, in order to keep the skin as easy as possible under such distension. Believing the tumour to arise from extravasated blood. I did not choose to open it, that the bleeding might be sooner stopped by the pressure of the extravasated blood against the sides of the cavity. Some hours after the accident the skin burst, and a good deal of blood came away. On examining the wound, I found the opening of considerable size, leading into a cavity as large as the egg of a goose, and filled with coagulated blood, which I did not remove for the reason given above, that it might assist in stopping the vessels which were still bleeding. The poultice was continued, the bleeding gradually became less, and every time I examined the part I found the cavity diminished, but still filled with coagulated blood, which continued to be pushed out of the wound, and after some time a slough came off from the bruised skin, which enlarged the size of the wound. About a fortnight after the accident the parts were all so much collapsed as to have forced out the blood entirely, and there seemed only a superficial sore, not above an inch long and half an inch wide. What may it be supposed would have been the consequence if I had enlarged the opening, scooped out the blood, and dressed the part with lint, or any other application I might think proper1? The effect of such treatment would certainly have been a large sore, nearly of the same size with the cavity ; and the sides of the cavity would have inflamed and suppurated. Is there not reason to believe that the coagulated blood, by remaining in the wound, prevented inflammation over the whole surface, and allowed the parts to contract to their natural position, so as to leave no other sore than that where the skin had burst and sloughed 1 This practice should be generally followed in such cases of ecchymosis. The second species of ecchymosis is that in which the blood has not coagulated but remains fluid. This case, although it also frequently occurs, does not always terminate so well as the former, nor allow of such a salutary termination, where an opening" has been made, either by the accident or by art, for then suppuration will be produced all over the cavity ; more caution is, therefore, necessary to prevent an opening. It has often the appearance of an encysted tumour ; but, being an immediate consequence of some accident upon the part, its nature becomes readily understood, though sometimes from its situation it has the symptoms of an aneurism attending it, neither does the cause of it contradict this idea. UNION BY THE FIRST INTENTION. 239 If formed over a large artery, the tumour will be attended with a pulsation; but when from this cause it cannot be made to subside by pressure, yet it is not, therefore, to be supposed harmless, as in fact it requires to be treated with great caution. If the pulsation should arise from the real influx.of blood, this will soon be shown by the increase of the tumour, and will lead to the proper treatment, viz., opening it and stopping the bleeding vessel.* This seldom happens from contusion, the kind of accident destroying in some degree [the texture of the parts, and] the free exit of the blood out of the artery ; and if the tumour should not increase after a certain period, even if there be a pretty evident pulsation, we may then be certain that it assumes this symptom from some neighbouring artery or arteries. The ecchymosis which is produced on the head of a child during birth has sometimes a pulsation, arising from that of the brain, as the sutures are still open; and every tumour of the scalp, whether from a blow or any other cause, may be mistaken for aneurism, if it appears before the fontanel be closed, and should it be opened without proper examination may disconcert the ignorant surgeon. That the blood does not coagulate in this species of ecchymosis, must arise from some peculiar mode of action in the vessels, occasioned by the effects of the injury; for I apprehend that in such cases the blood dies in the act of extravasation, in the same manner as the blood of the menstrual discharge whenever it is effused. The ecchymosis which we have mentioned as happening very commonly to children in the birth, particularly under the scalp, requires nothing to be done, as by waiting with patience the whole will in general be absorbed ; but although this is commonly the event in new-born infants, yet ecchymosis does not terminate alike favourably in other cases, the tumour often remaining for a considerable time without undergoing any change, and after months sometimes disappearing, but at other times inflaming and suppurating. When an extravasation of blood takes place between the scalp and head in consequence of a blow, which is very common, and continues fluid, we find a kind of ridge all round the bag, and by pressing all round the edge of the bag the finger sinks, so as to give distinctly (as we conceive) the feeling of a depressed bone; but this feeling of a depression following the edge of the ecchymosis all round, is a proof that it cannot be depression of the bone, because no depression could be so regular, nor would any depression be of the same extent with the ecchymosis. The edge of the scalp surrounding the ecchymosis seems to be raised, and I believe it is; if so, then something similar to the adhesive inflammation must have taken place to set bounds to the extent of the

* [This constitutes the false diffused aneurism of authors, which always requires that the vessel should be secured both above and below the wound with as little delay as possible. The pressure of the effused blood on the superior portion of the artery often prevents any pulsation from being perceptible.] 240 HUNTER ON THE BLOOD. bag, and to hinder the blood from getting into the cellular membrane. It might, perhaps, be the best practice to make a small opening into such tumours with a lancet, and by letting out the blood, get the sides of the cavity to heal by the first intention.* When the parts inflame and suppurate, the case is to be treated as an abscess. This sometimes disappears by resolution; but this being seldom permitted, the ecchymosis is reduced either to the state of a fresh wound, which is allowed to suppurate,or an abscess; for surgeons are induced to open early by seeing an inflammation and feeling a fluctuation, two strong motives when every circumstance is not well attended to; but in such cases I should wait till I observed evident signs of suppuration, viz., the thinning of the skin over the matter, and pointing of the contents, which are the only true marks of the formation of matter, as well as of its coming near the skin. If the blow should have deadened a part of the skin, then a separation of the slough will take place, and expose this cavity so as to produce suppuration. And this is to be considered as a step still further removed from the most simple species of injury than where the blood coagulates. I am not able, under such circumstances, decidedly to say which is the best practice, whether to leave the slough to separate, or to make a small opening and allow the blood to escape slowly from the cavity. In both kinds of ecchymosis, when inflammation has taken place in the skin from the violence, if it has not advanced to suppuration, the object of the surgeon should be to bring about the resolution of the tumour: when he finds there is no further increase of the tumour, he may conclude that resolution is beginning to take place, which being clearly ascertained, he is then to assist in exciting the absorbents to do their duty, in order to take up the extravasated blood. I believe the best stimulus is pressure, which, if urged beyond the point of ease, sets the absorbents of the part to work, for the purpose of removing the substance which presses, or the part that is pressed; but most commonly the body pressing, if it be subject to the laws or powers of absorption ; and in this case the extraneous substance pressing on the inner surface of the cavity is the extravasated blood which we wish to have removed. The following cases explain this. A lady fell and struck her shin against a stone; a considerable ecchymosis came on almost immediately, and the skin over it inflamed to a considerable degree. The blood had not coagulated; there was therefore a perceptible fluctuation underneath, and her physician recommended an opening to be made. I was sent for, and on examining the part, was rather of opinion, from the surface being a regular curve, and no part pointing, that matter had not formed ;

* [It can rarely be necessary to interfere with these cases, which generally do well under a simple treatment. The liability of the scalp to erysipelatous inflammation renders it particularly inexpedient to make any breach of the surface.] UNION BY THE FIRST INTENTION. 241 I therefore recommended patience; the subsiding of the inflammation, and the application of such pressure as she could bear without uneasiness, caused the whole tumour to be absorbed. A man was brought into St. George's Hospital whose thigh had been run over by the wheel of a cart; a very large ecchymosis was formed on its inside, and a considerable inflammation of the skin had taken place. The blood had not coagulated, therefore a fluctuation could easily be felt; but as there was no appearance of pointing, similar to that of matter coming to the skin, I was in hopes that suppuration was not coming on ; and although the inflammation was considerable, I supposed that it might arise rather from the violence of the accident than from the extravasation: I waited, therefore, the event; saw the inflammation gradually go off, and as that subsided I observed the tumour diminish, although it was very slow in its decrease. I then directed a slight compress to be applied, after which the tumour evidently diminished much faster than before, till the whole was absorbed. The union by the first intention usually takes place so soon after the injury that it maybe said to be almost immediate, for when the blood has coagulated in such a situation as to adhere to both surfaces, and so as to keep them together, it may be said that the union is begun. It is not, however, immediately secure from mechanical violence, and the blood itself, by losing its power of retaining life, may likewise be rendered unfit to preserve the communication with the adhering surface, by which it is connected with the body at large, and thus the union be of course prevented. If there be no such impediment, then the union of the parts may be very quick ; but it will be in some degree according to the quantity of extravasated blood interposed, for if that be large, the whole blood will not become vascular, but the surface only which is in contact with surrounding parts, and the rest will be absorbed as in the ecchymosis. Where the quantity is small, as in a slight wound without laceration, and where all the divided surfaces can be brought into almost absolute contact, their union will be firm in twenty-four hours, as happens in a hare-lip or wounds of the scalp. Although under such circumstances the blood seems to change into a solid form very quickly, yet when the situation of the wound particularly subjects the parts to mechanical violence, we should not trust to this union being completed in so short a time. In the hare-lip, for instance, perhaps forty-eight hours may be required to make it perfectly secure, and except when the stitches, by producing ulceration, might make scars, there can be no harm in allowing such parts even a longer time for their union. But in wounds of the scalp this caution is not necessary, and indeed in such cases it is scarcely required to make stitches at all. In cases of accidental injury, whether they be in themselves slight or considerable, in whatever situation or part they may have happened, if the salutary processes, above described, go on readily, no other effect of injury, or irritation, or pain, in consequence of na- 21* 242 HUNTER ON THE BLOOD. ture's operations, is felt. No universal sympathy or fever takes place, except what arises from the mere injury done, but all is quiet as if nothing had happened. This is sometimes the case even in a simple fracture of the bones of the leg, in fissures of the skull, etc. However, the magnitude of the accident often produces eflects which are alarming, and more particularly when they happen to parts essential to life. These effects are often the cause of much danger, the constitution becoming affected according to the nature and importance of the parts injured. Thus concussion and extravasation affecting the brain, must likewise affect the constitution, from the natural action and influence of this organ on the body being diminished, increased, or otherwise disturbed. The same thing happens from an injury done to any other vital part of the body, and the effects will be according to the use of such parts, or the influence which they have on the system. However, these immediate and salutary operations do not always take place simply, for they are often altered by other circumstances, as the accident sometimes becomes the cause of irritation, and produces another operation of the parts, called inflammation, whichjs often of singular service, by increasing the power of union in the broken parts. This inflammation will generally be in proportion to the degree of injury done, the nature of the parts injured, and the state of the constitution at the time, which, in other words, is in proportion to what is requisite for the first powers of union. But it sometimes happens that inflammation goes further than is required, and produces a variety of actions succeeding each other in regular progression.* This may occasionally be observed in certain simple fractures, in which the extravasated blood acting as an extraneous body, becomes the cause of the suppurative inflammation; and the simple is in this way brought to a state resembling the compound

* [Among the conditions necessary to insure the success of union by the first intention, those which refer to the constitutional peculiarities of the individual are most deserving of attention ; as, for instance, a predisposition to gout, scrofula, rheumatism, or erysipelas, which will often be excited into action by the merest breach of surface, and thus frustrate the designs of the surgeon. The same thing will also happen from internal organic disease, from what is called the inflammatory diathesis, arising from over-nutrition ; from long-protracted disorders of the digestive organs; and above all, from a peculiar and unnatural excitability of the nervous system, induced by debilitating causes, especially by the abuse of spirits, and accompanied as it usually is by a weakly frame of body. It is extraordinary how slight a cause will be sufficient in such cases to excite inflammation of a dangerous character, accompanied with local gangrenous tendency and all the worst symptoms of typhoid fever. To this head may also be referred the important fact noticed by Mr. Travers, viz., that the inflammation and fever which follow injuries and operations, severely affecting the nervous system, and through it the circulation, are generally found to be modified by the preceding state of the system, so as to assume in their progress a low or typhoid character. Inflammations occurring in such states of the body are apt at once to run into suppuration, without previously passing through the adhesive stage. The propriety of paying attention to these circumstances previously to undertaking operations, especially those of convenience, is too obvious to be insisted on.] UNION BY THE FIRST INTENTION. 243 fracture. The inflammation, however, does not extend over all the lacerated parts, as when they are exposed at the time of the injury, many of these having united by the first intention. We may here observe, that accidents of the most simple kind may produce effects which do not allow the common operations of nature to take place, as when a large blood-vessel is broken, or when a fractured rib penetrates into the lungs, or the compression of the brain arises from a fracture of the skull. But none of these accidents admit of the modes of cure above mentioned, as they each require particular treatment, and therefore are not to our present purpose.

§ 2. Of Injuries where the Wound communicates externally.

The second division of injury arising from accident is where the ruptured parts communicate externally, producing effects different from the former. These may be divided into two kinds, viz., wounds made by a sharp-cutting instrument, and contusions producing death in the parts injured. Wounds are subject to as great a variety as anything in surgery. A wound is a breach made in the continuity of the solids of a part, beginning most commonly on the external surface, and proceeding inwards, although sometimes its direction is from the inside outwards, as in compound fractures. A gunshot wound may be said to partake of both circumstances, as it passes through a part: wounds often admit of the same mode of cure with accidents which do not communicate externally ; but then it requires the art of the surgeon to place them in the same situation, or under the same circumstances. A wound is either simple or compound; the simple is what I have now to explain, and is of such a nature as to admit of union by the first intention. Of this description we may likewise consider wounds which are the consequence of certain surgical operations. The form of the instrument by which wounds have been inflicted will also make a difference in their nature ; for if it be sharp it will make a clean-cut wound; if obtuse in its shape a bruised one, and may also deaden a part, and the parts may likewise be torn after having been cut; all of which varieties will render a different treatment necessary towards effecting a cure. In the most simple cases of wounds, a number of blood-vessels being divided, there is an effusion of blood, which escaping by the wound, the internal parts are left exposed, especially the cellular membrane : and these, if not brought into contact with corresponding living parts immediately, or by means of the coagulated blood, will inflame and suppurate. Accidents of this kind differ from those of the first division by communicating externally, a circumstance which makes them often require very different modes of treatment. In cases where parts have been forced out of their 244 HUNTER ON THE BLOOD. natural situation, they should be reduced, that when cured they may answer their natural purposes, as in fracture, dislocation, occ. Wounds admit of three modes of treatment, arising from their size, situation, and the nature of the parts wounded. One mode is artificial, two are natural: in which last the constitution* is allowed to perform the cure in its own way, which will be explained when we speak of scabbing. These being different from the former and from each other, it might be thought that I should have considered them first as being natural processes; but the first can be put into the same state with the two others, and therefore ought to precede them. For this purpose art must be employed by the surgeon to bring the separated surfaces into contact; that, by retaining them there till union shall have taken place, the injury may be removed from the stale of an exposed wound. This treatment of fresh wounds, with a view to cure them by the first intention, is equally proper after many operations as in accidental injuries. Instances of this often occur after dissecting out tumours, scalping when no fracture is found, and when trepanning has not been performed; and it has been put in practice even where the trepan has been applied. It has been employed also after amputations; in short, wherever a clean-cut wound is made in sound parts, and when the surfaces can be brought into contact, or where there is sufficient skin to cover the part, this practice may and should be followed. In no case, however, of a breach of continuity can we entirely prevent the parts from retaining the appearance of a wound; for the breach in the skin will more or less remain, and the blood will coagulate, become dry, and form a scab. But this operation of nature reduces the injury to ihe state of a mere superficial wound, and the blood, which is continued from the scab to the more deeplyseated parts, retaining its living principle, just as the natural parts do at the bottom of a superficial wound, the skin is forue i under this scab in the one case as in the other; yet if the scab should either irritate, or a part underneath lose its uniting powers, then inflammation, and even sometimes suppuration, may be produced. It is often, however, only inflammation that is produced; the scab here preventing the further progress of mischief in the same manner as the scabbing of the pus on a sore prevents the process of suppuration, which becomes one of the uses of pus. In many of the cases in which we mean to produce union by the first intention, it is not necessary to be very nice in sponging out the blood, with a view to make the two surfaces of the flesh come entirely into contact, the blood itself answering a similar purpose.* In several cases, having brought the two portions of loose skin together, I have seen the two cut edges unite almost immediately; and though the cavity underneath was distended with blood, yet it

* [The impropriety of this advice will appear from the note at the end of this chapter.] UNION BY THE FIRST INTENTION. 245 did well, the tumour gradually decreasing as the blood was absorbed; this is to be considered in the same light as an ecchymosis. When the portion of skin is not sufficient to cover the whole wound, and the cut edges cannot be brought together, still the skin should be made to cover as much as it can, in order to diminish the size of the parts that must otherwise suppurate and form a sore; as, in consequence of this mode of treatment, the living extravasated blood is confined in the wound, and coagulating there unites the two surfaces together. The mouths of the vessels are soon shut, either by inosculation or their own power of contraction, and by the blood becoming vascular, as in the former stated case of union by the first intention; and if there should be any superfluous extravasated blood, we know that it will be afterwards absorbed. The blood being alive, this uniting medium becomes immediately a part of ourselves, and the parts not being offended by it no irritation is produced. The red particles are absorbed, and nothing but the coagulating lymph is retained, which being the true living bond of union, afterwards becomes vascular, nervous, &c. This mode of treatment by art, though an imitation of the former, can seldom be supposed equally complete; perhaps we ought not to expect it to be so in any case, as there are circumstances often attending the artificial mode of treating wounds which do not occur in the natural. The ligature used for tying a blood-vessel leaves an extraneous body in the wound ;* a part deprived of life by the instrument, &c, will become an extraneous substance, and the surfaces cannot always be brought into contact, so as to allow a perfect union to take place. In such cases, union is prevented by the blood losing in part its living principle, especially in those parts next to the external surface; and perhaps the art employed by the surgeon himself may assist in changing the original state of the wound, as the passing of needles and ligatures must always produce suppuration through the whole passage. These substances, so circumstanced, most probably become the cause of irritation, and consequently of inflammation. But if the position of the parts be such as in any sort to allow of union, although not readily, the inflammation will go no further than the first stage, and will even give assistance to the first mode of union. The possibility of effecting a cure by this method is probably limited to some certain distance of time after the wound has been received, though that space may admit of some latitude; perhaps the sooner it is done the better; but while the blood continues to be extravasated it certainly may be attempted upon our first principles of union.

* If such a wound has a depending angle, and the vessels should even be tied nearer the upper angle than the lower, yet I would advise to bring the loose end of the thread out of the wound at the lower, for by that means the matter will flow much more easily. 246 HUNTER ON THE BLOOD. Where the former bond of union is lost in a part, to produce a new one a secondary operation takes place, namely, inflammation; and if this is likewise lost, then a third mode of union will arise, which is by means of granulation. If the divided parts are allowed to remain till the mouths of the divided vessels are entirely shut, inflammation will inevitably follow, and will furnish the same materials for union which are contained in extravasated blood, by throwing out the coagulated lymph; so that union may still take place, though some time later alter the division of the parts. This inflammation I have called the adhesive; and the inflammation that precedes suppuration I have called the suppurative inflammation.* If the parts, however, continue too long asunder, suppuration must follow, and pus is unfriendly to union. We may here observe, that suppuration takes place on exposed surfaces with a much less degree of inflammation and in much less time than on those which are not exposed, and from their not being opposed by living surfaces, which tend to bring on the adhesive state, they continue it much longer. Whether this coagulating lymph issues from the half-closed mouths of the vessels which were cut, or from the surface of the open cells, is not easily determined, but most probably it is from the latter,t as it comes "on about the same time that the swelling of

* [It is now generally considered that union by the first intention and adhesive inflammation are essentially the same processes, modified by the degree of inflammation. Union by the first intention is uniformly attended with some degree of pain and swelling, together with increased heat and vascularity, which, taken conjointly, constitute the definition of inflammation. I may observe, that Mr. Hunter's language is doubly objectionable: first, because it implies two kinds of inflammation, instead of two stages of the same kind ; for suppuration is invariably preceded by adhesion, or the effusion of coagulable lymph ; while, on the other hand, adhesion may always be converted into suppuration by simply increasing the irritation: secondly, because the word termination implies that the inflammation ceases upon the occurrence of adhesion, suppuration, or mortification, which is by no means true in all cases, nor to the full import of the word in any case. Practically speaking, the language certainly expresses an important fact, which is, that the occurrence of either of these phenomena greatly mitigates the inflammatory action.] t [This opinion is rendered probable from the analogy which exists between the cellular and serous structures. There cannot be any doubt, in respect of the latter, that the same vessels are capable of secreting a simple healthy serum, a turbid unhealthy serum, serum and lymph, lymph mixed with pus, or pure pus corresponding with the degrees of inflammation present, or irritation applied; but if this may happen to the pleura or peritoneum, why not also to the cellular membrane ! which is similar in structure and function, and each cellule of which may be regarded as a small serous bag, in which all the phenomena of serous membranes are represented in miniature. Precisely the same phenomena are exhibited by serous membranes, cellular tissue, and recent wounds, under inflammation, and therefore it is probable that the lymph which in the two former cases is poured out without breach of surface, is also poured out from the same class of vessels in the latter case. The centre of a common phlegmon contains pus, because there the inflammation is greatest: the areola external to this is consolidated by the effusion of lymph; and still beyond this there is effusion of serum, producing simple oedema—exactly corresponding to the exudation, 1, of serum, 2, of coagulable lymph, and 3, of pus, from the surfaces of a recent wound or from the superficies of a serous membrane which has been irritated.] UNION BY THE FIRST INTENTION. 247 the surrounding parls begins to appear. There is reason to suppose it to be the same kind of discharge with that which causes the swelling, and which is continued through the whole course of this stage of inflammation; for on examining the dressings of such wounds as are allowed to suppurate, several days after the wounds have been made, the lint is generally adhering to the surface by means of the coagulating lymph, the suppuration not having yet sufficiently taken place to loosen it. When these operations are completed in due order, the simple operations of the animal are entirely confined to the part, neither the mind nor the constitution seeming in such cases to be at all affected, except that there is a feeling of tenderness in the part. But whatever these sensations may be, they arise entirely from the injury done, and not from the operation of union, unless when the suppurative inflammation comes on. The inflammation often runs so high, even where the parts have been brought into contact, as to destroy, by its violence, that union which the extravasated juices were intended to produce, the consequence of which is suppuration at last. Is it by this excess of inflammation that the extravasated juices lose their living principle, and become as it were extraneous bodies'? or is it not possible that in these cases the inflammation may be the effect rather than the cause of the loss of the living principle, by the blood first losing its living principle, and inflammation arising from it as a consequence 1 The time required to complete this union will be nearly the same as that required for union by the first intention, and probably less if there be no particular tendency to suppuration; but if there be, union may be suspended some time longer, for heje the uniting medium will be thrown out in larger quantity; and where the union is most easily effected there is less of this medium ; when two surfaces unite by inflammation, they are commonly in contact, or else most probably union from this cause would not so readily take place. We shall find in the description of the adhesive inflammation that the union of two sides of a circumscribed cavity is very soon effected, and soon becomes strong. There is another mode of union, which, although upon the same principle, yet differs with regard to the parts which are to be united. I have hitherto explained union as taking place only in the division of corresponding parts of the same living body, but it is equally possible to unite different parts of the same, or of different bodies, by bringing them into contact under certain circumstances. There is seldom occasion for such practice ; but accident, or rather want of attention, has in some cases been the cause of union taking place between different parts of the body. The chin has been united to the breast, the tongue to the lips or cheek, etc., and when this happens it has commonly been through the medium of granulations. The attempt to unite parts of two different bodies has only been recommended by Taliacotius. The most extraordinary of all 248 HUNTER ON THE BLOOD. the circumstances respecting union is by removing a part of one bodv and afterwards uniting it to some part of another, where on one'side there can be no assistance given to the union, as the divided or separated part is hardly able to do more than to preserve its own living principle, and accept of the union. The possibility of this species of union shows how strong the uniting power must be. By it the spurs of the young cock can be made to grow on his comb, or on that of another cock; and its testicles, after having been removed, may be made to unite to the inside of any cavity of an animal. Teeth, after having been drawn and inserted into the sockets of another person, unite to the new socket, which is called transplanting.* Ingrafting and the inoculating of trees succeed upon the same principle.f

* [See the ensuino- chapter, and On the Diseases of the Teeth, p. 57; also Boronio, Degli innesli Animali, 1804, in which work an account is given of the transference of portions of the integuments from one part of an animal to another with perfect success—experiments, it may be observed, which strongly corroborate the testimony of Fiovaranti, Molinelli, Garengeot, Dionis, Makau, Balfour, Barthelemy, Piedagnel, &c, respecting the reapphcation and subsequent growth of parts, as of the nose, tips of the fingers, lips, &c, which have been completely severed from the body. The Rhinoplasty or Taliacotian operation has been revived of late years, and applied with considerable success to the cure of several species of disease and deformity. Thus, Sir Astley Cooper has applied it to the cure of fistula? in perinso attended with loss of substance ; Mr. Lynn to the restoration of the under lip, upon which the beard afterwards grew; Mr. Earle to supply the place of the cicatrices of burns; and a great many other surgeons, particularly on the Continent, to the restoration of the nose, cheeks, lips, &c] fThat the living principles in two bodies which have a perfect affinity to one another should no° only be a preservative, but a cause of union, is evident; but even in bodies which appear foreign to one another the stimulus of an extraneous body is not produced where union is not intended, and cannot take place, although we should at first suppose that the extraneous stimulus would be given, and suppuration succeed.a This is verified by the egg3 of many insects, which are laid under the skin of different animals, producing only the adhesive inflammation in the surrounding parts, by which the skin is thickened and a nidus is formed for the eggs. The Guinea worm, called vena medenensis \Filaria Medinensis, Rudolphi], is also a striking instance of this ; for while the animal is endowed with the living principle, it gives but little trouble, yet if killed it gives the stimulus of an extraneous body, which produces suppuration through its whole length. Other instances of the same sort are, the oestrum bovis \_CEstrus bovis, Fabricius,] which lays its eggs in the backs of cattle ; the oestrum tarendi [(Estrus tarandi (both back and nose of reindeer,) Fabricius], which lays its eggs in the back of the reindeer; the oestrum nasale [ibid.], which lays its eggs in the noses of reindeer ; the oestrum haemorrhoidale [(Estrus equi, or Gasterophilus equi, Leach,] which lays its eggs in the rectum of horses ; the oestrum ovis [^(Estrus ovi, Fabricius], which lays its eggs in the nose and frontal sinuses of ruminating animals, particularly sheep ; the little insect in Mexico called migna [Acarus americanus, Linnaeus], which lays its eggs under the skin : and lastly, the cheggars [Pulex penetrans, Linna?us], which get into the feet of animals.

a [The author, I apprehend, is mistaken in saying that no stimulus is given in those cases. Generally, if not always, sacs are formed for the lodgement of these ova, just in the same way as for bullets or other extraneous inert substances, by the effusion of lymph and consolidation of the neighbouring textures.] UNION BY THE FIRST INTENTION. 249 !j 3. Practical Observations respecting Union by the First Intention. It is with a view to this principle of union that it has been recommended to bring the sides or lips of wounds together; but as the natural elasticity of the parts makes them recede, it has been found necessary to employ art for that purpose. This necessity first suggested the practice of sewing wounds, and afterwards gave rise to various inventions in order to answer this end, such as bandages, sticking-plasters, and ligatures. Among these, the bandage commonly called the uniting bandage is preferable to all the rest, where it can be employed ; but its application is very confined, from being only adapted to parts where a roller can be used. A piece ot sticking-plaster, which has been called the dry suture, is more general in its application than the uniting bandage, and is therefore preferable to it on many occasions. I can hardly suppose a wound, in any situation, where it may not be applied, excepting penetrating wounds, where we wish the inner portion of the wound to be closed equally with the outer, as in the case of hare-lip. But even in such wounds, if the parts are thick and the wound not large, the sides will seldom recede so far as to make any other means necessary. The dry suture has an advantage over stitches, by bringing a larger surface of the wound together, by not inflaming the parts to which it is applied, and by neither producing in them suppuration or ulceration, which stitches always do.* When parts, therefore, can be brought together, and especially where some force is required for that purpose, from the skin not being in large quantity, the sticking-plaster is certainly the best application. This happens frequently to be the case after the removal of tumours, in amputations, or where the sides of the wound are only to be brought together at one end, as in the harelip ; and I think the difference between Mr. Sharp's cross-stitch, after amputation, as recommended in his Critical Inquiries, and Mr. Alison's practice, shows strongly the superiority of the stickingplaster or dry suture. In those parts of the body where the skin recedes more than in others, this treatment becomes most necessary ; and the scalp probably recedes as little as any, it is therefore seldom necessary to apply anything in wounds of that part. The

* [It is almost unnecessary to say that these different modes of keeping the sides of wounds in contact may be conveniently united, especially the interrupted suture and sticking-plaster. In operations upon the eyelids and other similar parts, where the use of sticking-plaster is inadmissible, from the difficulty of its application, the interrupted suture may be employed with the greatest advantage. At the end of from twenty-four to thirty-six hours the union by lymph will be accomplished, and the ligatures may then be withdrawn without producing either suppuration or ulceration, or leaving any permanent marks. Sutures may be employed in a multitude of other cases, concurrently with sticking-plaster and bandages, with the greatest advantage. The evils attributed to this practice by Pibrac and some of the French academicians are entirely visionary. Sutures, however, should always be confined to the skin, and ought never to be inserted in tendinous parts.] 22 250 HUNTER ON THE BLOOD. practice will certainly answer best in superficial wounds, because the bottom is in these cases more within its influence. The sticking-plasters should be laid on in stripes, and these should be at smell distances from each other, viz., about a quarter of an inch at most, if the part requires close confinement; but when it does not, they may be at greater distances. This precaution becomes more necessary if the bleeding is not quite stopped, for there should be passages left for the exit of the blood, as its accumulation might prevent the union, although this does not always happen. If any extraneous body, such as a ligature, should have been left in the wound, suppuration will take place, and the matter should be allowed to vent at some of those openings or spaces between the slips of plaster. I have known a very considerable abscess formed in consequence of this precaution being neglected, by which the whole of the recently united parts has been separated. The interrupted suture, which has generally been recommended in large wounds, is still in use, but seldom proves equal to the intention. This we may reckon to be the only one that deserves the name of suture ; it wras formerly used, but is now in a great measure laid aside in practice, not from the impropriety of uniting parts by this process, but from the ineffectual mode of attempting it. In what manner better methods could be contrived, I have not been able to suggest. It is to be understood that the above methods of bringing wounded parts together, in order to unite, are only to be put in practice in such cases as will admit of it; for if there was a method known, which in all cases would bring the wounded surfaces into contact, it would in many instances be improper, as some wounds are attended with contusion, by which the parts have been more or less deadened; in such cases, as was formerly observed, union cannot take place according to our first principle, and therefore it is improper to attempt it. In many wounds which are not attended with contusion, when we either know or suspect that extraneous bodies have been introduced into the wound, union by the first intention should not be attempted, but they should be allowed to suppurate, in order that the extraneous matter may be expelled. Wounds which are attended with laceration, although free from contusion, cannot always be united by the first intention, because it must frequently be impossible to bring the external parts or skin so much in contact as to prevent that inflammation which is naturally produced by exposure. But even in cases of simple laceration, where the external influence is but slight, or can be prevented (as we observed in treating of the compound simple fracture), we find that union by the first intention often takes place ; the blood which fills up the interstices of the lacerated parts having prevented the stimulus of imperfection in them, and preventing suppuration, may afterwards be absorbed. JVIany operations may be so performed as to admit of parts uniting by the first intention, but the practice should be adopted with UNION BY THE FIRST INTENTION. 251 great circumspection ; the mode of operating with that view should in all cases be a secondary and not a primary consideration, which it has unluckily been too often among surgeons. In cases of cancer it is a most dangerous attempt at refinement in surgery.* In the union of wounded parts by the first intention, it is seldom or never possible to bring them so close together at the exposed edges as to unite them perfectly by these means; such edges are therefore obliged to take another method of healing. If kept moist, they will inflame as deep between the cut surfaces as the blood fails in the union, and there suppurate and granulate; but if the blood is allowed to dry and form a scab between and along the cut edges, then inflammation and suppuration of those edges will be prevented, and this will complete the union, as will be described by and by. As "those effects af accidental injury which can be cured by the first intention call up none of the powers of the constitution to assist in the reparation, it is not the least affected or disturbed by them ; the parts are united by the extravasated blood alone, which was thrown out by the injury, either from the divided vessels, or in consequence of inflammation, without a single action taking place, even in the part itself, except the closing or inosculation of the vessels, for the flowing of the blood is to be considered as entirely mechanical. Even in cases where a small degree of inflammation comes on, it is merely a local action, and so inconsiderable, that the constitution is not affected by it, because it is an operation to which the powers belonging to the parts themselves are fully equal. The inflammation may produce a small degree of pain, but the operation of union gives no sensation of any kind whatever. The first and great requisite for the restoration of injured parts is rest, as it allows that action which is necessary for repairing injured parts to go on without interruption; and as injuries often excite more action than is required, rest becomes still more necessary. But rest may be thought to consist merely in abstaining from bodily exercise;" this will in general be proper, as most parts of the body will be affected either immediately, as being engaged in the action itself, or intermediately by some connexion with the injured

* [Where inflammation has already come on, so as to threaten suppuration, it is generally not advisable to attempt union by the first intention. In amputations also, where the parts are consolidated and thickened by previous inflammation, it generally answers better to allow the process of suppuration to unload the cellular tissue ; and when granulations begin to appear, to draw the edges of the wound gradually together. In operations where, from the nature of the parts, the skin cannot be kept in contact with the subjacent parts, as in the removal of the testicle, tumours from the axilla, groin, &c, the cure will generally be effected more rapidly by inducing suppuration at once, by which tne formation and accumulation of matter in inconvenient situations will be avoided. 1 he surgeon will find many other occasions for putting in practice the excellent advice of our author, to consider the mode of union by the first intention as only of "secondary'''' importance.] 252 HUNTER ON THE BLOOD. parts. Thus, if the injury be in the limbs, and not such as to prevent walking altogether, still persons should not be allowed to walk; and we find, from the want of this caution, complaints in those parts are commonly longer in recovering than in others ; for by keeping the limbs at rest the whole progressive motion is stopped, a thing more disagreeable to the mind than any prevention of motion in the body. If an arm be injured, it is not so; the want of its use is not so distressing to the patient, because he can enjoy locomotion, and may have no objection to keeping his hands quiet. Rest is often admitted from necessity, as in ihe fracture of a leg, but seldom where motion is only an inconvenience. But it must appear that the rupture of a vessel requires union as well as the fracture of a bone, although the vessel having more powers of restoration within itself than the bone, and having less occasional disturbance from other powers, especially than fractures of the lower extremities, yet the rest should be proportioned to the mischief which would follow from the want of it; and this will vary according to the situation of parts. The same principle of rest should apply to every injury, although this is not often allowed to be the case. Thus, where an injury produces inability to move a part, especially a joint, it is, from fear of the loss of motion, not only allowed to be moved by its own muscles, which would be the most proper mode, if motion at all was necessary, but is moved by the surgeon, or by his direction, who, not satisfied with mechanical violence, has recourse to stimulants, as warm applications, in order to rouse up the internal action of the parts, and at the very time when everything should be kept quiet till restoration of the injury has taken place. In many parts of the body this practice is not so injurious as in others, in which it may be attended with very serious consequences. Thus, when a man has suffered a concussion of the brain, and perhaps a bloodvessel has given way, the mind is deranged, becoming either defective or too acute; and if these symptoms should continue but a little while, the medical assistant applies blisters to remove the effect, either forgetting or not rightly judging the cause. This is even carried further: we hardly see a man taken with all the signs of an apoplexy where a paralysis in some part takes place, or hemiplegia,* but that he is immediately attacked with cordials, stimulants, electricity, etc. Upon a supposition that it is nervous, debility, etc., the poor body is also tortured, because it cannot act, the brain not being in a condition to influence the voluntary muscles: we might with exactly the same propriety stimulate the fingers when their muscles were torn to pieces. I must own I never saw one of them which had not an extravasation of blood in the brain when opened, excepting one, who died of a gouty affection

* It may be observed here, that the only difference between an apoplexy and hemiplegia is in degree, for they both arise from extravasations of blood. UNION BY THE FIRST INTENTION. 253 in the brain, with symptoms similar to apoplexy.*f Such a case, most probably, would require a very different mode of treatment, therefore when rt happens to a gouty man, blisters to the head, feet, etc., would probably be the best practice ; but surely this would not be the proper practice in a rupture of a vessel; we ought to bleed at once very largely, especially from the temporal artery, till the patient begins to show signs of recovery, and to continue it till he begins to become faintish. We should give saline purges freely, to°diminish impetus and promote absorption; then great quietness should be enjoined, and as little exercise of body as possi. ble, and especially to avoid coughing and sneezing. Flam food should be directed, and but little of it; nor will such cases ever allow of being roused to action, when as much recovered in their texture as nature can accomplish, to the same degree that other parts will admit of or even require. These observations lead us to consider the means of relief, tor, besides rest, it often happen: that the parts can be relieved from the secondary consequences of the injury, such as inflammation, etc. But this leads to constitutional and local treatment, and will be included in the history of inflammation. I have already mentioned that when the salutary effects above described take place, the constitution is not in the least affected; yet it is proper in all cases where much mischief might arise from a failure, to pay a little attention to the constitution. The patient should eat plain food, drink weak liquors, and have the body kept open This treatment, with rest suitable to the case, will in many instances prevent evils that might otherwise occur and prove troublesome.

The operation which I have described prevent inflammation, especially that sort of it which produces suppuration ; but even where the parts are not brought together, so as to admit of union by the first intention, nature is always endeavouring to produce the

* For many years I have been particularly attentive to those who have been attacked with a paralytic stroke, forming a hemiplegia I have watched them while alive, that I might have an opportunity to open them when dead ; and in all I found an injury done to the brain, in consequence of the extravasation of blood. I have examined them at all stages, when it was recent, some of weeks standing, others of months', and a few of years', in which I saw the progress of

^'ITrhTVact which is here stated, as well as the condemnation of stimulants, althouBh generally true, must be taken with some exceptions. Apoplexy and hemiplegia not. unfrequently occur without the slightest trace of sanguineous, or even of "serous effusion, being discoverable after death, such cases seemingly deoendincr on simple inanition, sudden congestion of the brain, narcotic poisons, or a hiffhfy exalted state of nervous irritability. In some of these cases common sense Too plainly directs to a stimulant mode of treatment to make tt doubtful, although this treatment is not necessarily exclusive of local depletion.] 254 HUNTER ON THE BLOOD. same effect. The blood which is thrown out in consequence of the accident, and which would have united surfaces brought into contact, is in part allowed to escape, but by its coagulation on the surface a portion is there retained, which, drying and forming a scab,* becomes an obstacle to suppuration. The inflammation in this case may be greater than where union can be effected, but not nearly so great as when suppuration takes place. The blood lying on the fresh surface, although not now alive, and therefore not fitted for union with the living parts underneath, yet precludes the necessity of any further discharge as a covering to the exposed surface, which is one of the uses of pus. This might be considered as the first mode of healing a wound or sore, for it appears to be the natural one, requiring no art; and in the state of parts before mentioned, the complete union is in some degree indebted to this mode of healing, by uniting the edges that were not or could not be brought into close contact, by means of a scab; proper attention to this has, I believe, been too much neglected. Many wounds ought to be allowed to scab in which this process is now prevented; and this arises, I believe, from the conceit of surgeons who think themselves possessed of powers superior to nature, and therefore have introduced the practice of making sores of all wounds: as a scab, however, must always be on a surface, it is only on superficial wounds, or on superficial parts of deeper wounds, that scabs can form. How far this practice may be extended I do not know : but there are cases in which it should be discouraged, as where deep-seated extraneous bodies have been introduced, as in gunshot wounds, or where deeper-seated parts have been killed; but it will answer extremely well where the superficies only is deprived of life. Superficial hurts are very common on parts opposite and near to some bone, as on the head, shin-bone, fingers, &c, but more especially on the shin. In all such cases it is better to let them scab, if they seem inclined, or will admit of it; and, if that should not succeed, they can but suppurate at last, and no harm is done. In many deep-seated wounds, where all the parts have remained in contact, those underneath will unite much better if the surface be allowed to scab. Some compound fractures (more especially where the external wound is very small) should be allowed to heal in the same way; for by permitting the blood to scab upon the wound, either by itself or when soaked into lint, the parts underneath will unite, the blood under the scab will become vascular, and the union will be complete even where the parts are not in contact. How far this practice may be extended is not yet ascertained. A small wound doing well under this treatment is a common case, and

* ^t l°ab may be defined' first> dried blood on a wound, dried pus on a sore, a slough from whatever cause allowed to dry, mucus from an inflamed surface, as in the nose. UNION BY THE FIRST INTENTION. 255 some examples of large wounds are mentioned,* though these do not so generally succeed; but I do not know that there is any danger in the attempt. In many cases, therefore, which seem doubtful, where the external contusion is not very great, or not continued of the same size as in the deeper-seated parts, it may be tried. In some of those cases which have been allowed to scab, the parts injured have appeared ready to go into inflammation: a red circle has been seen all round, produced by the irritation of the scab. Suppuration takes place underneath the scab, and the pus makes its escape from under its edges ; but even in such cases, I should be cautious of treating it as a suppurating sore. I should allow it to cro on, and occasionally press the scab in order to squeeze out the pus; for it very often happens that the red circle surrounding the scab becomes of a dusky brown, which is the best sign of resolution, the suppuration diminishes, and the whole does well. But if inflammation should proceed further, and seem to be increased by the mode of treatment, it must not be urged further: the scab should be poulticed, in order to soften it, that it may come off easily, and the case should afterwards be treated according to the nature of the sore. This practice succeeds wonderfully well in cases where we find applications of all kinds disagree with the skin. A person shall get a blow on the shin which shall probably deaden a part; a poultice is then often applied; that poultice brings out pimples on the surrounding skin; these pimples increase and become sores of some breadth; the poultice is increased in breadth to cover them ; new pimples arise, and so on, till I have seen a whole leg full of those sores. In such cases I always allow the wound to scab; and, to accomplish this, the best way is to take off the dressings in the morning, and put on trowsers, without stockings, and by the evening the parts are scabbed; or we may powder them with lapis calaminaris, or chalk finely powdered, and desire the patient to go to bed, for the first night, with the trowsers on: where the sore has been only one, I have made a circular pad, and bound that on till the scab was formed. The mode of assisting the cure of wounds by permitting a scab to form is likewise applicable, in some cases, to that species of accident where the parts have not only been lacerated, but deprived of life. If the deadened surface is not allowed to dry or scab, it must separate from the living parts, by which means these will be exposed, and suppuration broughton; but if the whole can be made to dry, the parts underneath the slough will cicatrize, and the

* [Mr. Wardrop, in his Lectures on Surgery, has related a very remarkable case, in which "the largest wounded surface" he ever beheld, arising from the ablation of a diseased breast, almost entirely healed under a crust of blood, which remained on the surface of the wound for upwards of thirty days,—the process of granulation, approximation of the edges, and cicatrization of the wounds going on underneath, with scarcely any irritation or inflammation of the adjacent integuments. See Lancet, 1832-3, ii. 653.] 256 HUNTER ON THE BLOOD. dried slough will at last drop off. I have seen this take place after the application of a caustic, and many other sloughs. \\ here this can be effected it is the best practice, as it will preclude inflammation and suppuration, which in most cases should be avoided if possible. I have treated many cases in this way, and the living parts underneath have formed a "skin as the slough separated. This will more readily take place where the cutis is not deprived of life through its whole substance: for it has a much stronger disposition and greater powers to restore itself than the cellular membrane has to form a new cutis; indeed the skin formed upon entire new flesh is very different from the original cutis; therefore, as the skin is the part most liable to these accidents, we have the best chance of succeeding in this way when the cutis alone is injured. This practice is the very best for burns or scalds, after the inflammation has either been considerably prevented, or subdued by proper applications or by time, for which there probably are more remedies than for an inflammation arising from any other cause, as if there was something specific in such causes.* Whatever will abate an inflammation arising from accident will have the same effect upon a scald or burn; and, from the diversities of applications, we have opportunities of knowing the best. Oil was long an application, but which has no virtue : spirits of wine has also been long applied, and with very good effect. The common application, which is a soap made with lime-water and oil, seemed to answer better; and now vinegar is strongly recommended, and I think with justice, as far as I have seen. Cold lessens all inflammations, and is a very good application where it can be applied, but it cannot be applied so universally as many others ; however, cold has this disadvantage, that the pain, although removed while under the application, occurs with double force when it is removed, much more than from any of the other applications, and the reason is evident, for, as the warmth returns, the pain is increased by the warmth, even in sound parts. On the contrary, it is recommended that when a part is burnt to hold it to the fire as close and as long as it can be held, which undoubtedly lessens the succeeding inflammation, and soon gives ease. This 1 have often seen, and probably it can only be accounted for on the principle of producing the act of contraction in the vessels. I have taken a bucket of cold spring water with me, when I have made an attempt on a wasp's nest, and put my hand into it after having been stung; and while my hand was in the water I felt no pain, but when I took it out the pain was greater than when I put it in.

* [The intractable suppurative disposition which sometimes ensues on these injuries, added to the peculiar tendency which is exhibited by the cicatrices of burns to contract and degenerate into a semicartilaginous structure, would seem to indicate a specific mode of irritation. In many of these cases granulations appear to be produced after cicatrization, so as to give rise to a tuberculated appearance of the surface of the cicatrix, which raises it above the surrounding parts.] UNION BY THE FIRST INTENTION. 257 This is not the case with other applications, for their specific virtues are not counteracted by any natural circumstance attending the body, and then they can be applied with a continuance to any part where the skin is thin. The blisters commonly break, and so much the better, as the application can come in contact with the inflamed surface ; but as on the hand, foot, fingers, and toes, especially in working people and those who walk much, the blisters seldom break of themselves, they should be pricked with a needle to take off the tension.* When the inflammation has gone through its stages, then the parts should be allowed to dry. This in many parts is very awkward, as when a large surface of the body is scalded ; for exposure is necessary, and in some parts it is almost impossible, as behind the ears, arm-pits, fee. To keep the cloths from sticking to the parts, it is necessary to powder them with some inoffensive powder, such as lapis calaminaris, very finely powdered chalk, &c.; this does not hinder evaporation, which is the principle of scabbing; and if the discharge should be so much at first as to moisten the first powdering, then strew more over the whole till it forms a hard crust. This is hardly necessary on the face, but it will rather dry sooner by being at first powdered. In such cases nature will go on infinitely further than if the parts had been disturbed by our applications.

§ 5. Accidents attended with death in a superficial fart.

In the foregoing account of injuries done to the body, and of the modes of restoration, we have been so far from considering inflammation as one of them, that hitherto it has been inculcated to guard against it with the utmost care. It sometimes, however, takes place, and is one of the modes of restoration when the methods above mentioned fail, as well as a mode of restoring parts under disease. We shall therefore proceed to explain its principle ; but as there are accidents already mentioned, which often advance to suppuration, I shall now treat of them. Among the divisions of accidents, one is where death is produced in the injured parts, and where inflammation and suppuration must take place, in consequence of the dead parts which separate not being within the power of the former treatment to produce a cure; but it should be remembered that the inflammation, which is the forerunner of suppuration in such cases, is not nearly so great as even the inflammation arising from a wound that suppurates. In many accidents, such as bruises, the skin preserves its living powers, while the cellular membrane underneath has become dead ; this will afterwards produce an abscess, and must be treated as ab-

* [The advantage arising from the direct application of remedies can never compensate for the irritation which inevitably arises from exposure of the sensitive cutis to the atmosphere. The simple evacuation of the bullae, by gently puncturing them, relieves the tension, which is all that is required to be done.] 258 HUNTER ON THE BLOOD. scesses commonlv are, remembering that in the present case the abscess, after being opened, will be later in acquiring the healing disposition than abscesses commonly are; the dead cellular membrane must separate, which will come away like wet, dirty lint. It sometimes happens that in one part the skin, in another the cellular membrane only, shall become dead; and in such cases I have often observed that the bruised skin sloughs much sooner than the cellular membrane. An abscess, therefore, is frequently forming under the sound skin while the other parts are healing: a circumstance which often disappoints both the patient and surgeon. When the wound, or the dead part, is considerable, it is probable the treatment will in general be very proper ; because the degree of mischief calling up the attention of the surgeon, and producing acquiescence in the patient, he will be induced to submit to whatever may be thought necessary. The best application, at first, will probably be a poultice, which should be either simple or medicated, according to the nature of the succeeding inflammation, and continued either till the inflammation has subsided and suppuration come on, sufficient to keep the parts moist, or till the slough has entirely separated, when the sore may be dressed according to its particular disposition. But such accidents as have a superficial part killed (when the slough would readily separate and the parts suppurate kindly) are often treated improperly at first, by the patients themselves applying Friar's balsam, or some such medicines; but these not being within the power of scabbing, inflammation comes on and alarms the patient. A poultice is then commonly applied, which removes the first dressing, and the slough appears, which gives a disagreeable appearance to the wound, and it is supposed to be a foul sore. From such an idea various methods are employed, and the application of red precipitate, &c, but with no good effect, and the patient becomes fretted from a sore apparently so trifling being so difficult to heal; but it is impossible that such a sore can heal while there is a slough to separate. It is therefore the surgeon's business to inform himself of the nature of the complaint, to explain it to his patient, who will then become better satisfied, and less uneasy about his own situation. When this piece of slough comes away, the sore will put on an appearance according to the nature of the constitution or of the part, and is to be treated accordingly.

[According to the modern views the modes of union above detailed are always accompanied by adhesive inflammation, and should therefore have followed the ensuing chapter " On the Fundamental Principles of Inflammation." The parts are united, not by the extravasated blood becoming vascular, but by the effusion and organization of coagulable lymph. There are two principal objections to the doctrine as laid down by Hunter and supported by some modern physiologists: the first of which is that it assigns two distinct causes for the production of the same phenomenon ; and the second, that there is an absolute deficiency of direct proof of the organization of the coagulum, notwithstanding the frequency of hemor- UNION BY/ THE FIRST INTENTION. 259 rhagic effusions and the easy manner in which this question may be brought to the test of experiment. 1. There seems not the slightest reason for believing that the mechanism essentially differs by which naturally contiguous parts morbidly adhere, and that by which artificially divided parts unite from a principle of conservation, and yet all the phenomena of adhesion in disease uniformly point to the presence of inflammation and the effusion of coagulable lymph. Mr. Hunter indeed freely admits that blood is not necessary to union, but is only one of two modes, at the same time that he considers the coagulable lymph which is poured out in adhesive inflammation as different from the coagulable lymph of the blood. " It must," he says, " have undergone some change arising from the action of the vessels," which renders it different from " the coagulating lymph with its common properties. We should infer that this coagulating matter is not simply coagulating lymph such as it is when circulating, but somewhat different, from having undergone a change in its passage through the inflamed vessels." When therefore we consider that the fibrin of the blood and the plastic coagulable lymph which is thrown out in inflammation are not the same substances, or at least not in the same state ; that the coagulable lymph is the universal medium of adhesion in all cases of disease ; that it is thrown out also in all instances of recent wounds ; that it is sufficient of itself to effect their union ; and that the presence of blood invariably impedes and very often completely prevents this event: when, I say, we consider these circumstances, and take them together, we can scarcely refuse our assent to the position that coagulable lymph is the invariable agent in all cases of adhesion ; especially when we reflect, 2. That there is an absolute deficiency of direct proof on the other side ; for, whatever some may say, Mr. Hunter always speaks hesitatingly on this point. " I think," he says, " that I have been able to inject what I suspected to be the beginning of a vascular formation of the coagulum when it could not receive any vessels from the surrounding parts ;" and in one of his letters to Dr. Jenner, dated July 6, 1777, he says, "I do not remember Dr. Fordyce's ever supposing a polypus vascular. I should rather believe he supposed the contrary. You know it comes near my idea that the blood is the bond of union everywhere, but I should very much suspect that a polypus formed after death is not of that kind. I am pretty certain that I have injected them in arteries after amputations, and I have a preparation which shows and supports my theory." Now it is very remarkable, considering the frequency of extravasations of blood in the human body, that no unequivocal example of organized coagulum has yet been produced, and it is also material to observe that the examples of this kind which Hunter supposed he possessed were not calculated to carry conviction on such a point, for the injecting pipe being inserted at random into the substance of a coagulum of blood it could scarcely happen otherwise than that the injection should diffuse itself through the substance of the clot, as through a sponge, and thus present some obscure resemblance to organization. Experimentalists have been able to inject, from the adjoining vessels, the organized coagulable lymph within twenty-four hours after its effusion, but this has never been done in regard to the blood. Effusions of blood have been known to exist in the brain and cellular membrane, and in the cavities of the great vessels and aneurismal sacs, for months and even years, and yet so far from becoming organized or 260 HUNTER ON THE BLOOD. identified with the surrounding parts they have invariably acted as foreign bodies, producing either inflammation and consolidation of the surrounding textures into sacs for their protection, or suppuration for their speedy expulsion. The argument from tumours is much too unsatisfactory to be admitted to have any weight in this question (see note, Principles of Surgery, p. 150); and the same may be observed of the facts referred .to by the author (pp. 119 and 236), in which coagula of blood were found adherent to the insides of the coats of veins, or to the tunica vaginalis of the testicle. Nothing can be concluded from observations made at so great a distance of time from the occurrence of the injuries, which are just as likely to have occasioned an effusion c»f lymph as an effusion of blood. Not to mention that if blood had been effused it would probably not have presented so defined an outline, and would have gravitated to the bottom of the sac. Modern physiologists, however, have brought forward another series of proofs derived from the products of organization being found in the centre of recent clots, such as pus, encephaloid matter, the matter of cancer, scrofula, melanosis, &c. A vast variety of these apparent transformations or degenerations of sanguineous coagula into fibrous, osseous, or morbid growths, independently of any connexion with the surrounding parts, have been reported by modern pathologists, (Andral, Clin. Med. iv. 683, and Precis d'Anat. et Path. i. 537. ii. 407 et passim.—Gendrin, Hisloire des Inflammations.—Reynaud, Journ. Hebd. de Med. ii. 84.—Dr. Burrows in Medical Gazette, xvi. 678.—Arch. Generate de Med. Oct. 1834, p. 223, &c.) while others have not hesitated to ascribe the origin of phlebolites to the same source. (Lee, in Cycl. of Pract. Med., art. Veins.) I may observe, however, that these are doubtful explanations of obscure morbid phenomena, and cannot with any justice be applied to the establishment of a leading doctrine respecting the reparative processes of the healthy structure. We know enough of the proneness of all organic bodies to undergo various important transformations arising from slight changes of chemical constitution, independently of the actions of vitality, to make us hesitate in attributing such changes in the blood to the operations of life ; especially when there is no single proof of the presence of organization by which this can be supposed to be effected. The delineations of vascular coagula given by Sir Everard Home, and his speculations on the subject of the formation of blood-vessels by the evolution of carbonic acid gas, are too vague to be formally combated : the permeation of loose coagula under the vacuum of an air-pump is not surely to be wondered at, and would equally take place in a deal board under similar circumstances. (See Phil. Trans. 1818, pp. 172. 185, and Preparations in Museum, Nos. 23 b, 23 c, 23 d, and Catalogue of Physiological Series, i. 4.) The use of the blood seems to be entirely provisional, and intended merely to serve the purpose of agglutinating the edges of recent wounds, so as to defend them from the contact of the external air until the coagulable lymph is poured out. The lymph thus poured out incorporates with the blood, and in proportion as the former becomes organized the latter becomes absorbed. The reader is referred to Chapter III. on Adhesive Inflammation for a more particular account of this process.] FUNDAMENTAL PRINCIPLES OF INFLAMMATION. 261 CHAPTER II.

FUNDAMENTAL PRINCIPLES OF INFLAMMATION.

An animal in perfect health is to be considered as a perfect machine, no part of it appearing naturally weaker than another; yet this is not strictly true; but still if no relative action, with regard to external matter, was to take place, the machine would, in itself, be tolerably perfect for its own actions. As the animal, however, is employed upon common matter, and therefore liable to accidents, which interrupt the natural operations, it becomes absolutely necessary for its continuance that it should possess, within itself, the power of repair; we find it accordingly endowed with powers of repair upon many such occasions ; but where parts give way from their own natural actions, this mischief cannot be repaired; because, if they are not able to sustain their own actions, they cannot recover when diseased or injured. It is found that some structures of parts more readily give way than others, and consequently are much longer in repair, either when diseased or injured by accident. We also find that different situations, of similar parts, give them advantages or disadvantages with regard to their powers of restoration. This is principally known from injuries being done to them, or in consequence of those injuries from the attack of a disease. It is also shown in the common actions of the body or parts, of which, in health, we have comparative trials. We never can know what a thine is incapable of doing till it gives way, which giving way is either a disease, or that which is productive of disease; nor can we know the powers of restoration in the part till it is tried.*

* [The author's meaning seems to be, that where derangements of the animal ceconomy arise from injuries done by exteinal bodies, or by the undue action of those parts on which depend the animal functions, as contradistinguished from the organic, that there we find the parts possess a power of repairing the injury, or at least show a disposition to repair it, for they do not always succeed ; and this is certainly true. A blood-vessel may be ruptured in the lungs, or a bronchitis occasioned by too violent exertions of the voice; the eye may be inflamed by employing the organ too long on external objects, or the brain by too great mental exertion; and yet the innate resources of the ceconomy may be found sufficient to right the system under these evils, just in the same manner as if they had arisen from external violence : but let these same derangements proceed from the natural actions of parts performing the organic functions, and then they will be irremediable, for the very spring and source of all power in the system is then vitiated at its fountain-head. The above observations, however, must be taken with many limitations, for we are 9eIdom able to say what diseases arise from the natural actions of parts, independently of external iufluences. In the instance adduced of thickening of the valves of the heart, we know that certain external actions tend to produce this lesion ; whilst, again, we cannot say that it is one necessarily arising after a time, and therefore natural; for we do not always find it in old people. Scrofula, rickets, fever, inflammation, &c, frequently arise spontaneously, and, as we 262 HUNTER ON THE BLOOD. As a proof that parts cannot always be proportioned to the action or powers applied which have no action within themselves, but are only acted upon by external force, we adduce the instances of a broken patella or broken tendo-Achillis, or a thickening of the valves of the heart. In the first, however, there is commonly another power superadded besides simply the actions of the parts, viz., the body falling and being stopped at once. In the valves of the aorta, however, and the valvula mitralis, we have the best examples, for they become thickened from the actions of the parts themselves; while no such effect takes place in the valves of the pulmonary artery : even an aneurism proves the same. Where there is a difference in structure there are comparative powers to resist the consequences of actions, attended with injury, such as their admitting more or less readily of thickening, ulceration, or mortification, and their comparative powers of restoration. When we compare the pdwers of restoration in muscle, nerve, cellular membrane, ligament, tendon, bone, etc., with each other, they are found to be very different. Muscles, skin, and probably nerves, possess the greatest powers of that kind ; and the cellular membrane, ligament, tendon, bone, etc., the least, and are, in this respect, pretty equal among themselves. How far elastic ligaments have powers of resistance and repair I do not know, but I should suppose they have them in a very considerable degree, from the vessels not giving way so readily as in many of the others.*

presume, from some fault in the ordinary organic functions, and yet the resources of the system prove adequate for the cure, and often increase with the increasing exigencies of the case. In gout, as in many of the exanthemata, the very evil, or materies morbi, which oppresses the system, and which is, at the same time, the product of systemic derangement, becomes the stimulus by which the constitution is enabled to throw it off. Morbid growths and degenerations of structure are probably the only cases really so situated as to be beyond the natural poweTS of recovery ; and yet even here it sometimes happens that the parts get rid of the evil in another way, that is, by sloughing, as in cases of cancer.] * [It is singular that Hunter should attribute to the cellular membrane so low a power of reparation, when in fact it would seem to possess this power in a higher degree than any other tissue of the body. Cruveilhier declares it to be the only self-repairing tissue, and that by means of which the actions of restoration are carried on in all the others; and accordingly, we find that as we descend the animal scale, and the other tissues disappear, leaving the animal more and more largely indebted to the cellular membrane for its composition, so does the power of reproducing mutilated parts increase. The power of reparation and reproduction enjoyed by this tissue, as compared with its other vital endowments (which seem to be of the lowest kind), is certainly not a little extraordinary, and seems to rank with the analogous fact of the superior tenacity of life in the lower animals, which obviously increases as the organization becomes more and more simple,—the powers of action not being in them, as our author supposed in regard to the higher animals, any indication of the powers of life (see pp. 13 and 221 ante), but seemingly the reverse; the energy and variety of action of any part cr animal being generally inversely to the tenacity of life and the powers of reproduction and reparation. This fact affords some ground for the opinion of Blumenbach, that generation, reproduction, and reparation, are merely to be regarded as modifications of the same process. It may perhaps be stated in ge; eral terms, that the proneness of parts to fall into disease as well as to recover from it, when once they have deviated from FUNDAMENTAL PRINCIPLES OF INFLAMMATION. 263

Their comparative powers become pretty evident inmost of their diseases, but chiefly, I think, in mortification. As mortification is the most simple effect of debility, it gives the comparative powers of parts in the most simple manner. We find that muscles, skin, and often blood-vessels, stand their ground, while they are deprived of their connecting membrane, which has either sloughed off or ulcerated; tendons likewise slough off as far as these muscles, and stop there. I have also observed, that difference in the situation of similar structures in the body makes a material difference both in the powers of resistance to injuries, and of reparation when injuries have taken place. This difference seems to arise in proportion to the distance of the parts from the heart, or source of the circulation. Thus, we see muscles, skin, etc., becoming more readily diseased in the legs than anywhere else, and more slow in their progress towards a cure; but this is not wholly to be laid to the charge of situation or distance from the source of the circulation, some portion of it is to be attributed to position, the legs being depending parts, and those parts which are most distinct happen also to be the most dependent.* We find an horizontal position assist in the repair of such parts, but even then they are not equal in their powers to parts situated about the chest; the difference therefore is principally to be attributed to situation, or distance from the heart. The same disease that showed the comparative powers between the muscle and tendon, shows also that they are equally affected by position ; thus we see ulceration and mortification taking place in the lower extremity, as such, more readily, and with less powers of repair, than happens in parts near the chest. This is still more the case if the person be tall. This is seen by changing a limb from a horizontal position, in which it was easy, to a dependent one, wherein it feels pains; because the new position increases the length of the column of blood in the veins. I am inclined to believe that the retardation of the cure is more owing to a stagnation of the blood in the veins, from the length of the column, than from a deficiency in the motion of the blood in the arteries. As the readiness of a part to fall into disease, and its backwardness to admit of cure, arises from position, it is in some degree compensated by rest and a change of the position. These differences in the structure, situation, and position of parts in the body, make, I believe, but little difference in the progress of specific diseases: the venereal disease, however, certainly does not

the healthy action, are nearly in proportion to each other, and very nearly in proportion to their vascularity and complexity of organization. Thus the inflammation of bone, cartilage, and of the white tissues generally, is much more intractable and much slower in its progress than that of the more vascular parts ; but then the former parts are much less disposed to become inflamed, being, as it were, wisely protected by their want of vascularity from those evils to which, from their situation and uses, they would otherwise be obnoxious.] * We find in most authors the whole laid to this, which I shall more fully discuss in the history of opinions. 264 HUNTER ON THE BLOOD. make such progress in bone, tendon, etc., as in the skin; nor does the cure advance so rapidly in those parts; but both these effects may be attributed to another cause, which is, that bones and tendons are more deeply seated. I believe, however, that position makes no difference in the disease itself, although it may have some influence upon the power of cure, and perhaps in all specific diseases, in the progress towards a cure; for a venereal sore is always approaching nearer and nearer to the nature of a common sore, and therefore is more and more readily influenced by what influences a common sore. But in diseases for which there is at present no cure, as the cancer, I believe it makes no difference where it is situated, or in what it is placed, except in the case of such parts as have a tendency to such diseases, which no one of the parts above mentioned has more than another. I have so far considered, in the general way, the comparative powers of different structures, of different situations, and of different positions in some parts of the body when affected by disease. Disease is the only circumstance which exposes these principles to our view ; but to see how far the same principle was carried in natural operations, of which the most remarkable is the growth of parts, I made several experiments on fowls. The first was the common experiment of transplanting the spur of a young chicken from its leg to its comb, in which experiment I always found that the spur on the comb, when it took root, grew much faster and became much larger than that left on the leg. This I attributed to the greater power of action in the comb than in the leg, although they are pretty nearly at equal distances from the source of the circulation ; but probably position also favoured it, as there was no stagnation in the veins of the head. In the power of producing such effects in disease, as well as in the growth of parts, I was then desirous to know the comparative degrees between the male and the female. T wished also to ascertain if the parts peculiar to the male could grow on the female, and if the parts of a female, on the contrary, would grow on a male. Although 1 had formerly transplanted the testicles of a cock into the abdomen of a hen, and they had sometimes taken root there, but not frequently, and then had never come to perfection, yet the experiment could not, from this cause, answer fully the intended purpose ; there is, I believe, a natural reason to believe it could not, and the experiment was therefore disregarded.* I took the spur from the leg of a young cock, and placed it in the situation of the spur in the leg of a hen chicken; it took root, the chicken grew to a hen, but at first no spur grew, while the spur that was left on the other leg of the cock grew as usual. This experiment I have repeated several times in the same manner, with the same effects, which led me to conceive that the spur of a cock would not grow upon a hen, and that they were, therefore, to be considered as dis- * Vide p. 248, and Volume on Teeth, p. 57. FUNDAMENTAL PRINCIPLES OF INFLAMMATION. 265

tinct animals, having very distinct powers. In order to ascertain this, I took the spurs of hen chickens and placed them on the legs of youno- cocks. I found that those which took root grew nearly as fast, and to as large a size as the natural spur on the other leg, which appeared to be a contradiction to my other experiments. Upon another examination of my hens, however, I found that the spurs had grown considerably, although they had taken several years to do it; for I found that the same quantity of growth in the spur of a cock, while on the cock, during one year, was as much as that of the cock's spur on the hen in the course of three or four years, or as three or four to one; whereas the growth of the hen's spur on the cock was to that of the proper spur of the cock as [one to two ?] two to one. These experiments show that there is an inequality of powers in different parts of the same animal, and that the legs have much less than the comb; they also show that there is a material difference in the powers of the male and the female. The spurs of a cock were found to possess powers beyond those of a hen, while at the same time, the one animal as a whole has more powers than the other; yet when I apply these principles to the powers of cure in local diseases of the two sexes in the human race, I can hardly say that 1 have observed any difference. It is to be observed, however, that women commonly live a much more temperate life than men, which certainly must have considerable influence both with regard to resisting and curing diseases. In all complicated animals, among which man is the most complex, the parts are composed of different structures, and we find that in such animals the powers of action of those different structures within themselves are very different; when they are therefore excited to any common action, the varieties produced should be well known and particularly attended to. Besides, every similar structure in different animals does not always act in the same manner. Thus we cannot make a horse vomit; nor can we give many specific diseases which attack the human subject to any other animal, more particularly the morbid poisons. The mode therefore of action in one animal does not implicitly direct to the mode of action in another; nor does the same structure in the same animal always act in the same way at all times: it acts at various times in a way similar to the same structure in various animals; and, besides, the same structure varies its action in different situations in the same animal. Besides, the exterior actions of life make a very material difference in the internal actions of animals, or in the excitement of disease, either universally or locally; for there are parts which cannot bear one mode of life,while there are other parts which cannot bear another, —parts and mode of life being in opposition with each other. A great many of these varieties depend upon the difference in the natural strength and weakness of the parts; but as those vary very considerably in different habits, so the varieties are increased ; and 23* 266 HUNTER ON THE BLOOD. likewise, as many occurrences in life produce the principle of strength or weakness, we have those varieties still more increased, as well as disease. These observations, as heads, I shall treat more fully, but not as my principal subject, attending to them only so far as they are connected with inflammation and may illustrate the varieties in that action. § 1. Of the different Causes which increase and diminish the susceptibility for Inflammation either in the whole body or in parts.

Susceptibility for inflammation may be said to have two causes, the one original, the other acquired. The original constitutes a part of the animal ceconomy, and is probably inexplicable. Of the acquired it is probable that climate and modes of life may tend considerably either to diminish or increase the susceptibility for inflammation. The influence, however, of climate may not be so great as it commonly appears to be, for it is generally accompanied by modes of life that are not suited to others ; and if we consider how much less pernicious many climates are now than they were formerly, arising from the mode of living being different, we may be led to allow less influence to climate; and, on the other hand, if we consider how diseases become multiplied and varied in the same climate, we shall see that climate alone is not attended with so much variety as may have been supposed. It is observed by some of the ablest physicians of this day that the fever called inflammatory is now not so common in this country as it was formerly represented to have been; that it is now seldom that in fevers they are obliged to have recourse to the lancet, at least to that excess which is described by authors in former times. They are now more obliged to have recourse to cordials than evacuations, and indeed the disease called the putrid fever and putrid sore throat are but of late date. I remember when the last was called FothergilPs sore throat, because he first published upon it and altered the mode of practice. I remember when practitioners uniformly bled in putrid fevers; but signs of debility and want of success made them alter their practice. Whether the same difference takes place in inflammation I do not know, but I suspect that it does in some degree, for I am inclined to believe that fever and inflammation are very nearly allied, that is, that either will be according to the constitution, which is not the case with specific diseases, excepting in their common modes of action, which consist either in fever or inflammation; but 1 believe we have much less occasion for evacuations in inflammation than there was formerly ; the lancet therefore in inflammation, and also purgatives, are much more laid aside. How far climate varies the constitution, so as to alter the nature of diseases, I do not at FUNDAMENTAL PRINCIPLES OF INFLAMMATION. 267

present know; but it would appear from Dr. Blane's account that inflammation is hardly a disease in the West Indies. How far an alteration in the mode of life is the cause of this difference I will not pretend to say, but certainly the way of life is very much altered. We certainly live now more fully than what they did formerly: we may be said to live above par. At the full stretch of living, therefore, when disease attacks us, our powers cannot be excited further, and we sink, so as to require being supported and kept up to that mode of life to which we have been accustomed. A kind of constant state and variety of mind may often alter constitutions so much as to alter the mode of diseased action, which is much more common in some countries than others. We may be pretty certain that this state of mind often produces the inflammation of the gout. Probably there is but little power in art to correct the susceptibility of inflammation; however, if the susceptibility of the body be similar to that of the mind it ought to be in some degree corrected by art. The mind is corrected by reason, together with habit, but the body can only have the last employed upon it: it might be made less susceptible by the immediate causes coming slowly upon it, or by avoiding those causes, and even acting in diametrical opposition to them. This will at least answer in the acquired susceptibilities. The acquired susceptibility for inflammation, or indeed for any other disease as it is acquired by art or habit, may be lessened simply by a cessation of those habits ; and if the habit is of any particular kind, which is always ascertainable, then the habit of the contrary is to be used, which must also be ascertainable. Strength and weakness are the opposites of each other, and therefore must have very different effects in disease. They haVe very different powers in resisting disease, in their mode of action, and also in their readiness to terminate that action. Strength, probably, under every circumstance, produces good effects, or at least it is always more in the power of management by art than weakness. I can conceive, however, that too much strength might act with too much power, becoming unmanageable under disease that excites action. In inflammation when the constitution is strong then it will be commonly the most manageable, for strength lessens irritability. But in every kind of constitution inflammation will be the most manageable where the power and the action are pretty well proportioned ; but as every part of the body has not equal strength, these proportions cannot be the same in every part of the same constitution. According to this idea of strength, the following parts, viz., muscles, cellular membrane, and skin, and more so in proportion as they are nearer to the source of the circulation, will be most manageable in inflammation and its consequences, because they are stronger in their powers of action than the other parts of the body. The other parts, as bone, tendon, ligament, &c, fall into 268 HU.NTER ON THE BLOOD. an inflammation which is less in the power of art to manage, because, though the constitution is good, yet they have less powers within themselves, and therefore are attended with the feeling of their own weakness ; and I believe they affect the constitution more readily than the former, because the constitution is more affected by local disease when the parts have less power within themselves of doing well, and the effects, if bad, on the constitution reflect a backwardness on the little powers they have. Strength and weakness of the constitution, or of Darts, are synonymous terms with a greater or less quantity ^ animal life, or living principle joined with powers of action.* The inflammation, if in vital parts, will be still less manageable; for although the parts themselves may have pretty strong powers, yet the constitution, and the natural operations of universal health, become so much affected that no salutary effect can so readily take place, and therefore the disease becomes less manageable. If the vital part is the stomach, or such as the stomach readily sympathizes with, inflammation in such parts will be still less

* [See note, p. 262. It is not easy to fix the exact import of the words " too much strength" as used by our author. Properly, as applied to the constitution, strength should mean not only a vigorous but a well-balanced action of the various organs of the body amongst themselves; and, as applied to parts, a just equalization of the various functions carried on in individual parts, such as the nervous, vascular, secretive, absorbent, nutritive, &c. In this sense the strength can never be in excess; but probably our author simply intended to express a tendency to excess of action of some one function or organ over that of another, which forms no part of strength. It is an important practical truth, however, that persons who habitually live "above par" are the worst subjects to cope with any serious shock to the system ; a tendency to diffuse cellular inflammation, gangrene, and low typhoid symptoms being a usual result of the effort made by the constitution under such circumstances to reestablish itself. As to parts " having a feeling of their own weakness," it is obvious that such expressions explain nothing when examined into, but contribute to keep true knowledge out by deceiving us with the semblance of it. If we find that the constitution is more injured by a disease affecting some structures than others, it should be our business to inquire strictly into the various facts connected with the two cases, with a view of drawing some general deductions from them, and not be satisfied with allegorizing the vital powers. At present I believe we must be content to regard it as an ultimate fact that parts affect the constitution in proportion to the weakness of their reparative powers; the whole system being, as it were, called upon to cooperate and unite its strength in support of the feeble part when it comes to be diseased. I would observe, by the way, that such cases as these mark more than any others the distinction between mere physiology and pathology. The most exact knowledge of the anatomical and physical properties of the tissues, of their morbid appearances after death, and of their functions in a state of health, would afford little or no clue to the actual relations which subsist between them and the constitution in a state of disease. The mere physiologist might predict with tolerable certainty the leading consequences of inflammation affecting the vital organs, but he would be totally at a loss to conjecture th;; effects of disease afflicting the different tissues (as, for example, the serous) without actual observation ; a remark equally applicable to the therapeutic part of the art, and worthy of the attention of those who build the knowledge of their profession too exclusively on the investigation of diseased appearances and on mere anatomical and physiological acquirements.] FUNDAMENTAL PRINCIPLES OF INFLAMMATION. 269

manageable, for no operation can go on well, either in the stomach, or in other parts where this viscus is affected, as the powers of restoration become weaker than ever. In weak constitutions, although the inflammation be in parts which admit of the most salutary operations in the time of the disease, and in situations the most favourable to restoration after disease, yet the operations of inflammation are proportionably more backward as to their salutary effects in such constitutions, and more or less according to the nature of the parts affected, which I shall now consider more fully.

§ 2. Effects of strength or weakness of Constitution, and of Parts, ichile under Inflammation.

Whatever is to be the consequence of injuries, especially inflammation, is produced much more readily in a strong constitution than in a weak one. A wound, for instance, made upon a person of a healthy constitution and sound parts will unite almost at once: it admits readily of a union by the first intention. A greater strength of constitution and of parts admits of resolution, while in the adhesive state of inflammation, very readily, and therefore tends much to prevent the suppurative inflammation from taking place, for it gives a better disposition to heal by the adhesive; so that the union of parts by the first intention, the inflammation and resolution, as well as the readiness to change from the one to the other, according as the preceding is prevented, depends equally upon the strength and health of the constitution and parts inflamed. We may also observe that a greater strength and soundness of the constitution or parts inflamed, when the inflammation has got beyond the stage of resolution and has assumed the disposition for suppuration, hastens on inflammation and suppuration, and also brings it soon to a termination, while at the same time the matter is brought more quickly to the skin by ulceration. Whatever therefore is the step which nature is to take, whenever an injury is done or a necessity for inflammation has taken place, it is performed with readiness and facility in strong constitutions and parts. Weakness of constitution and weakness of parts are supposed to be the immediate cause of most tedious or chronic diseases. It appears to be often used as a general term, as have also nervous, bilious, to denote anything for which we cannot well account, and to which I am certain there has been affixed no precise meaning. Every action that is not acute, especially a mild continuation of some of the symptoms of a former viclent disease, is called weakness. Thus a gleet is called a weakness, fluor albus is called a weakness, diarrhoea is called a weakness: none of which I conceive simply to arise from weakness, for I believe that weakness seldom or never becomes an immediate cause of disease or action of any kind ; but it often becomes the predisposing cause of disease, 270 HUNTER ON THE BLOOD. many diseases not taking place except where weakness is an attendant, as agues, scrofula, nervous, &c, none of which are simple weakness; and it may continue many diseases when they have already taken place. This is, I think, very evident in many diseases which would terminate well if there was strength in the constitution to perform the right actions. However, where there is a strong susceptibility for any one disease, in which weakness might also become a predisposing cause, I can believe that in such cases weakness, especially if suddenly brought on, may become an immediate cause of that disease: as, for instance, a man may, from a wound or any other cause, have a strong tendency to a locked jaw. If you bleed that man freely it is a thousand to one but that a locked jawcomes on : weakness produces a consciousness of its own want of powers, or incapacity, which produces increased action, that even proceeds the length of unnatural actions, called nervous.* These effects are no less visible in acute diseases in such constitutions, which include accidents or violence of all kinds; for they run into two violent actions which is not of a salutary kind, and therefore may be called unnatural diseased action. When a wound is made in a person of a weak habit there is a great backwardness in the two cut surfaces to unite by the first intention, therefore inflammation takes place if there be strength of constitution to produce it, which is not always the case, so that in such habits inflammation is more likely to be a consequence; but this does not arise from a greater readiness to inflammation in the habit, but from a want of power and disposition to heal, which renders inflammation necessary. However, in this case the want of powers or disposition to unite may partly depend upon a different principle from that of weak parts or solids: it is probable that the blood of people of weak habits is weak in its living principle, which it therefore very soon loses upon extravasation, so as to become unfit for a bond of union, by which it degenerates into an extraneous body, and therefore the suppurative inflammation must take place if there be strength to produce it. In weak habits and diseased parts inflammation is slow in any of its salutary effects, and is hardly capable of either producing the adhesive or suppurative inflammation. If they should take place,

* [The author here seems to depart from the definition of strength and weakness given in p. 268. Weakness as opposed to strength should be considered merely as a less degree of energy of all the vital actions, while the balance between them is still equal, the degree of energy being generally in proportion to the vascularity, and activity of the circulation. In this view a weak constitution may be as healthy as a strong one, as in a man and a woman, and probably be even less exposed to attacks of disease; for a watch may last as long as a clock, provided it be taken equal care of, and keep the truest time of the two. Weakness, however, is used in another sense to signify the loss of balance between the vital actions, as in the present paragraph. Thus the loss of blood, by weakening the energy of the circulation without proportionally diminishing the innervation, may predispose to locked jaw; and probably most predispositions, whether natural or acquired, are of this kind.] FUNDAMENTAL PRINCIPLES OF INFLAMMATION. 271 it is but imperfectly, and the inflamed parts surrounding the suppurative surfaces are hardly capable of resolution, but continue inflamed ; we even find in many constitutions, where the animal powers are very much weakened, that, instead of their readily running into inflammation, it is hardly possible to promote it even from a breach of continuity in the solids, which in most other cases is surest of being followed by inflammation : such constitutions are in general those which are dropsical. I have seen several cases where the power has been so weak that the wound, after tapping, has not united by the first intention, nor has even acquired the adhesive state of inflammation, and has admitted water to pass through it from the abdomen for several weeks without the peritoneal inflammation being excited. In the same dropsical habits I have seen scarifications in the legs or feet not inflame, so that the cells were not united but continued to discharge the water for many weeks. In such cases of extreme weakness this total want of inflammation would appear to be a salutary effect; for in many dropsical cases, where the parts have powers to inflame, but not sufficient to go through the different stages of the inflammation, and at last resolve as in healthy constitutions, the inflammation generally produces a total loss of animal powers and the part mortifies, which often produces death in the whole, so that in such cases the parts only act to destroy themselves.* As a further proof that debility is o ften the cause of increased inflammation, in consequence of any violence, and often the cause of mortification, is plainly shown in Mr. Dick's account of dropsies among the troops in the East Indies. (Duncan's Edin. Med. Com., x. 207.) In the first year of the attack in any man he durst not venture to scarify the legs; but when they were attacked with the same disease the year following, which was often the case, whenever he attempted to scarify the legs a violent inflammation and mortification were the consequence. He was in this second attack obliged to have recourse to strengtheners; and we may observe that, in the case of tapping, if the constitution is irritable, the cavity of the abdomen commonly feels the effect, and inflammation of the peritoneum and death is the consequence. As the effect which this inflammation has upon the constitution is by sympathy, it must be in proportion to the readiness with which the constitution assumes that action. This susceptibility is stronger in some constitutions than in others ; and every constitution is more susceptible of sympathy with some parts of the body than with others. The kind of constitution which is least affected by this inflammation is that which is in general most healthy, where sympathy hardly takes place. This happens to be the case with such constitutions as can most readily perform all the different operations with ease ; and when the parts inflamed are able to manage their own business they thereby affect the constitution less; for we shall find that a constitution may be affected by a local * Vide paper on the recovery of drowned people, in next volume. 272 HUNTER ON THE BLOOD. disease merely because it is beyond the power of the part to cure itself. But it is to be observed that constitutions in full vigour, or which have not been in the smallest degree accustomed to local disease, take the alarm much more readily than those which are not in such full health, or which have been accustomed to local disease. Thus, if a man in perfect health gets a very bad compound fracture in the leg, or has his leg taken off, either for this fracture or in consequence of any other accident, he stands a much worse chance of recovery than one who has been accustomed to a local disease. Even the man with the compound fracture will do much better if his leg is not taken offtill the first symptoms are over;* or at least we may be certain that the symptoms arising from the amputation will not be nearly so great as those that arise at first from the fracture, or would have arisen from the immediate amputation. This would appear to be a contradiction to the above position; but, upon an accurate investigation, I think it may he accounted for; for, first, I do not look upon full health as the best condition to resist disease.! Disease is a state of body which requires a medium : health brooks disease ill, and full health is often above par; persons in full health are too often at the full stretch of action, and cannot bear an increase, especially when diseased ; and, as I before observed, it is a new impression on the constitution, and till it be in some degree accustomed to local disease it is less able to bear such as is violent; besides, the removal of a diseased part which the constitution has been accustomed to, and which is rather fretting the constitution, is adding less violence than the removal of a sound part in perfect harmony with the constitution: the difference, however, is not wholly owing to that cause, for the circumstance of a constitution being accustomed to a mode of life, &c, which it is to continue, makes a considerable difference.

* [The author, I apprehend, does not mean to advocate delay where the operation will certainly sooner or later become unavoidable, but only to state the fact that those who have long suffered from some local irritation generally bear operations the best. I may mention that the doctrine of delay is now universally disallowed by the best authorities, foreign and English, the most favourable time for operating being as soon after the constitution has rallied from the nervous impression caused by the accident as possible.] f [Exemption from disease may be compatible to a certain extent with a predominating action of some one system over another, as of the vascular or nervous ; yet such constitutions are ill adapted to contend with disease, and ought not in truth to be called healthy. The inhabitants of hot climates are prone to nervous diseases, as tetanus, &c, but are little obnoxious to inflammation ; while during the Peninsular war it was found that, the Portuguese, from being less disposed to inflammation, recovered from injuries which the English would certainly have died from, probably from the latter using a fuller and more stimulating diet, although both might previously have enjoyed equal apparent good health. The justness of Hunter's observation is remarkably exemplified in the case of draymen, bargemen, and such class of persons, whose habits of severe labour lead them to the habitual excessive use of fermented liquors and an inordinate diet, the consequence of which generally is that they form the worst class of patients in our public hospitals, and speedily succumb under severe operations.] FUNDAMENTAL PRINCIPLES OF INFLAMMATION. § 3. Of Parts of the Body most susceptible of the three different Inflammations to be treated of.

All parts of the body are susceptible of inflammation, although not all equally so; nor will all parts of the body admit readily of the three different kinds of inflammation I mean to treat of, some parts admitting readily of one only, others of two, and others of all the three ; which difference appears to be according to the situation of the inflamed parts in the body, and also the nature of the parts inflamed. The cellular membrane the first. The cellular membrane free from the adipose appears to be more susceptible of the adhesive inflammation than the adipose membrane, and much more readily passes into the suppurative. Whether this arises from surfaces inflaming more readily than other parts I will not pretend to say. Thus we see that the cellular membrane connecting parts together as muscles, and the cellular membrane connecting the adipose to muscles, easily inflames and runs readily into suppuration, and as it were separates the muscles from their lateral connexion, and even separates the adipose from the muscles, while the skin and adipose membrane shall only be highly inflamed, and the matter so formed must produce ulceration through all this adipose membrane to get to the skin, and then through the skin, in which last mentioned parts it is much more tedious: ulceration therefore does not so readily take place in those parts as it does in the common connecting membrane. Muscles, nerves, and blood-vessels are parts which nature wishes to retain, and the adipose membrane contains a substance which is properly no part of the animal, viz., oil: it may therefore be more difficult for this part to be absorbed than what are properly the parts of the animal itself.*

* [I believe it may be laid down generally that parts are disposed to suppurate in proportion as they are lax in structure, by which the blood-vessels are deprived of their due support and distended and ruptured with great facility A sort of scale marking the suppurative tendency might be formed on this principle, commencing with the mucous membranes, and passing on through cellular membrane, adipose membrane, skin, the free surfaces of serous membranes, the internal tunics of blood-vessels, the internal parenchymatous viscera, fibrous membranes, cartilage, bone, &c. The first step in the formation of an abscess seems to be the softening and breaking down of the tissues by the exudation of a mixture of serum, coagulable lymph, and blood ; so that if an abscess be opened early it will be found to contain rather a grumous bloody serum, together with broken down cellular membrane, than pure pus, such as would afterwards be formed ; and therefore the more the natural structure of any part favours this exudation and vascular distension the more readily will it suppurate. This at least seems to be a nearer approach to the true proximate cause why the cellular membrane goes more easily into suppuration than muscles, nerves, and bloodvessels, than the ascription of a " desire of nature to retain them," which at most is only the final cause allegorically expressed ; nor is it even this as regards the adipose matter, which is, in truth, very easily absorbed and redeposited, as we daily witness in alternate fatness and leanness. The gradual breaking up of the pulmonary tissue in inflammation of the lungs, and conversion of it into a diffuse 24 274 HUNTER ON THE BLOOD. As a deficiency in the power to heal becomes a stimulus or an incitement to inflammation, we find that similar parts, in proportion as they are removed from the source of the circulation, such as the lower extremities, are more ready to inflame than others not so circumstanced ; and what adds to this backwardness is their being depending parts, which adds to the incitement. The deeper-seated parts of the body, and more especially the vital, very readily admit of the adhesive inflammation, which is proved by dissections; for we hardly ever open a human subject where there are not in the circumscribed cavities considerable adhesions; and most probably many in the common cellular membranj, if they were equally visible. The deeper-seated parts, however, do not in common so readily pass into the suppurative inflammation ; and this readiness to accept of the adhesive most probably bec/Omes a cause why the suppurative inflammation does not so readily take place. But if the inflammation comes on at once, with great violence, it would appear to pass almost at once over the adhesive immediately to the suppurative action ; or perhaps where it may appear to have done this there may be an erysipelatous disposition ; for although it is not the disposition of the erysipelatous inflammation to suppurate, yet it has a greater backwardness to produce adhesions. This effect we often find take place in the abdomen, in the thorax, &c, and I have already mentioned that I suspect the erysipelatous inflammation does, in some degree, reverse the common rules of the common inflammation, by being more ready to suppurate in deep-seated parts than in the superficial, and extend much further towards the centre of the body. 1 suspect, too, that the coverings of the brain, viz., pia and dura mater, have something of this disposition. They appear 1o suppurate very readily, or with very little inflammation; for from a slight blow on the head we find these membranes much oftener suppurate than we should from a similar blow on the shin-bone; for instance, a blow on this bone will only produce suppuration on the external surface, very seldom in its internal cavity; but a blow on the head that shall not even produce the adhesive inflammation in the scalp shall make those membranes suppurate.* Inflammation, wherever situated, is always more violent on that side of the point of inflammation next to the external surface. This effect we often find take place in the abdomen, in the thorax, &c, and I have already mentioned that I suspect inflammation, wherever situated, if there be a continuity of parts between it and the external surface, will be greater on that side next to the external surface of the part than towards the centre of the part. This also equally takes place in inflammation, although close to the different

suppurative mass as contrasted with the other firmer viscera, strongly favours the above view.] * [This may be accounted for by the jar which the cranium receives, which often leads to the immediate separation of the dura mater from its internal surface. A blow on the dead body will produce the same effect] FUNDAMENTAL PRINCIPLES OF INFLAMMATION. 275

outlets of the body, and is probably most easily demonstrated in them. Thus, for instance, if an inflammation comes on in the socket of a tooth at its root, inflammation will not take place on the inside of the jaw, but towards the outside; and if it is beyond the union of the lips with the gum it will attack the skin over the inflamed part, while all the internal parts, such as the gums on both sides, but principally on the inside and tongue, if in the lower jaw, shall be perfectly sound. If an inflammation attacks the cellular membrane on the outside of the gut near the anus, although the gut is in contact with the inflamed part, yet the inflammation extends to the skin of the buttock, while the gut remains pretty free from inflammation. If an inflammation attacks the peritonaeum covering an intestine, and if adhesions between it and the peritonaeum lining the abdomen are a consequence, the inflammation immediately passes through the abdominal muscles towards the skin, while the proper coats of the intestines shall in most cases remain sound ; however, this is not always the case, although much more commonly so than the reverse. We see the same thing in the obstruction of the natural passage of the tears, called fistula lacrymalis, for there the sac and skin ulcerate on the inner angle of the eye, while the inside of the nose defends itself by becoming thicker, so much so in many cases as to stop the cavity of the nose and unite with the septum, which has been the cause of the failure of the operation for the fistula lacrymalis. We even find that if an abscess forms in a frontal sinus from an obstruction in its duct that the matter makes its way through the frontal bone externally, instead of getting into the nose. The same observations are applicable to abscesses in the antrum, which are common cases; and indeed, if we observe accurately, we shall find that nature rather defends such parts as are either deeper seated or on the inside of outlets, as will be explained hereafter. The specific qualities in diseases also tend more rapidly to the skin than to the deeper-seated parts, except the cancer ; although even in this disease the progress towards the superficies is more quick than its progress towards the centre. The venereal has something of the same disposition with the cancer, although not so much. In short, this is a law in nature, and it probably is upon the same principle by which vegetables always approach the surface of the earth. That this is a general principle in vegetation requires no illustration, but what is the immediate cause is not so easily determined. I conceived it might be the light, not warmth, for the ground is often warmer than the air or surface into which vegetables are often growing. To ascertain this as far as I could by experiment, I took a tub, about eighteen inches deep, and about two wide, and filled it with fine mould, in which I planted some beans and peas; their eyes were placed in various directions, and over the surface was spread a close-meshed net. The mouth of 276 HUNTER ON THE BLOOD. this tub was turned down, was raised about three feet from the ground, and was suspended between two posts. Round the tub, and over its bottom, which was uppermost, were placed wet straw, mats, &c.,to take oft'any influence the sun or air might have upon its contents, and a small hole was bored in its bottom, to which was fixed a small long tube that came through the straw. This was intended for pouring some water, if I found the earth get dry, into the tub. Under the mouth of the tub I placed looking-glasses, in such a way that the light was thrown upon the mouth of the tub, or surface of the earth. The weather was fine, so that through the whole day there was the reflection of the light from the looking-glasses upon the surface of the mould, which was much more powerful than daylight without the direct rays of the sun. This I continued till I conceived that the beans and peas had grown some length, but not finding their tops coming down through the surface of the mould, I examined the contents of the tub, and found that they had all grown upwards towards the bottom of the tub, and that in those whose eyes had been placed downwards the young shoot had turned round so as to arise up. As one experiment leads to another, I wished to see how a bean would grow if kept in a constant rotatory motion. For this purpose I put some earth in a basket, having the shape of a cylinder, and about a foot diameter, with the two ends of wood for greater strength, through the centre of which I fixed an axis or spindle; in this earth I planted a bean, about half way between the surface and axis, with its eye to the surface. The basket was laid across the mouth of a large tub, with the ends of the spindle resting on the edges of the tub, which were fitted to one another so as to allow of easy motion. Round the basket was rolled some small cord, to the end of which was suspended a box, water tight; into this was put lead, so as almost to make it sink in water, and which was sufficient to turn the basket round in the open air. This large tub was filled with water, and the box placed upon it, and the spindle with the basket placed across the mouth of the tub; a very small hole was bored at the lower end of the tub, which allowed the water to escape, but very slowly; as the water sunk in the tub the box descended, and as the box descended the basket was turned round. This tub took about twelve hours in emptying, and during that time the spindle with the basket only turned about one and a half. The tub was repeatedly filled, and when I conceived the bean might have grown some inches, if it had grown at all, I examined it, and found it had grown as much as if it had been planted in the common ground, but it had no particular direction but that of passing in a straight line from the bean, which was at first toward the circumference, the direction in which it was planted ; but in its course it had met with a small stone, which had turned it into the direction of the axis, and it had gone on in a straight line in that direction. Here, as there was no fixed inducement to grow in any one FUNDAMENTAL PRINCIPLES OF INFLAMMATION. direction, the bean grew in a straight line, in that direction given it by chance.* This circumstance of the deeper-seated parts not so readily taking on the suppurative inflammation as those which are superficial, is shown in cases where extraneous bodies irritate any parts ; for we find that extraneous bodies are in general capable of producing inflammation, but if these extraneous bodies are deeply seated, they may remain for years without doing more than producing the adhesive inflammation, by which means they are inclosed in a cyst, and only give some uneasiness; or if they are such as can be made to change their situation by the actions of the body upon them, as pins and needles, or from gravity, as is the case sometimes with bullets, then the parts through which they pass seem not to be much altered or disturbed ;f but if the same body was nearer to the skin it would produce suppuration. This is proved by the cases that have occurred of people swallowing pins, needles, etc.: they have been found to travel almost over the whole body, without producing any effect, except in some situations exciting some sensation; but when they have come near to the skin, the very same substance has generally produced suppuration. This principle shows itself very remarkably in the cattle which feed in bleaching fields; there is not one of these killed without having their stomachs, etc., stuck full of pins, and no seeming inconvenience takes place, for they appear to be healthy, and fatten as readily as other cattle. However, it is to be remarked that these pins are not found in the fourth or digesting stomach, therefore do not give that disturbance to the constitution that might be expected. It is probable that these cases of pins, etc., owe their want of power in producing suppuration, not entirely to situation but in some degree to the nature of the substance, metals perhaps not having the power of irritation beyond the adhesive, for when the adhesive has taken place the part appears to be satisfied. This appears also to be the case with the introduction of glass, even in superficial parts:

* [The experiments of Mr. Knight render it probable that the directions taken by the plumula and radicle of seeds is referable alone to gravitation, and may always be counteracted by centrifugal force. When beans were planted on the circumference of a wheel, which was made to perform 150 vertical revolutions in a minute, the radicles invariably receded from the axis, whilst the germens sought the centre. The same thing also happened when the motion was horizontal, but with this difference, that when the number of revolutions was 250 in a minute the direction of the radicle was ten degrees below the horizon, but fortyfive degrees below this line when the revolutions were reduced to 80, the germens always taking the opposite direction at a corresponding angle. (Phil. Trans. 1806, p. 99, and 1811, p. 209.) There seems, therefore, no ground for the analogy in the text.] f This circumstance of such bodies moving in various directions, and not towards the surface, is a proof of the truth of my principle, for their motion arises from a mechanical cause, and is ruled by it; whichever way it is directed they must move, whether by gravitation, as is the case with bullets, or by the mechanical pressure of the part upon the two ends of the pin, which will determine the motion towards the point. 24* 278 HUNTER ON THE BLOOD. a piece of glass shall enter the skin just deep enough to bury itself; inflammation shall come on; the wound in the skin, if brought together, shall heal by the first intention ; and the inflammation shall not exceed the adhesive, but rather degenerate into the disposition for forming a sac, by which means a sac is formed round the glass, and no disturbance is given to the irritability of the parts. This was the case with Mr. Knight, apothecary, who had a piece of glass three-fourths of an inch long run into the palm of his hand, and remained there for ten weeks, without any further inconvenience than retarding the motion of the hand, and sometimes giving a pricking pain, when the sac was made to press upon the points of the glass; this insensibility, however, arises from a sac being formed with such properties, but it cannot be assigned as a cause in the case of bodies moving as pins. Whether this fact, of external parts assuming the suppurative inflammation more readily than the internal, arises from unknown properties in the parts themselves, or from circumstances which attend situation, such as heat, cold, etc., is not easily determined; but whatever be the cause, the effects are good, as many situations of inflammation, viz., the internal, would prove dangerous if the parts were always, or often to suppurate; of two evils, nature chooses the least; while, on the other hand, when near the external surface, it becomes the least evil to produce suppuration, in order to get rid of the extraneous matter. Accidents may be assigned as one cause of this frequency upon the external surfaces, but the cases of pins above mentioned (which is accident), show, that even when it arises from accident, the parts near the external surface much more readily suppurate ; and in all cases arising from the constitution, or spontaneous, the external inflammations exceed the internal in number, violence, and extent.

§ 4. Of the two Parts that have the Orders of Inflammation respecting Priority inverted.

I formerly divided the surfaces capable of taking on inflammation into two; the first of these was the cellular membrane in general, together with the whole circumscribed cavities; the second was all the outlets in the body, commonly called mucous membranes ; for instance, all the ducts of glands, and the alimentary canal. The first order of parts, I have already observed, generally, if not always, takes the adhesive first, in the true inflammation, and then all the three inflammations in succession; for the adhesive is immediately admitted in the cellular membrane and circumscribed cavities, to exclude, if possible, suppuration, where suppuration, and of course ulceration, would prove hurtful. In the following parts the order.of inflammation, with regard to its being adhesive or suppurative, appears to be inverted; as the ulcerative is a consequence either of the adhesive or of the suppura- FUNDAMENTAL PRINCIPLES OF INFLAMMATION. ' 279 five inflammation, it is ruled equally by both. In internal canals,* where adhesions in most cases would prove hurtful, the parts run immediately into the suppurative inflammation, the adhesive inflammation in common being excluded; such parts are the internal surfaces of the eyelids, nose, mouth, trachea, air-cells of the lungs, oesophagus, stomach, intestines, pelvis of the kidneys, ureters, bladder, urethra, uterus, vagina, and indeed all the ducts and outlets of the organs of secretion, which all these parts mentioned may be in some degree reckoned, and which are commonly called mucous membranes. In such parts, if the inflammation is but slight, the suppurative in common takes place, which is almost immediate, as it is not retarded by the adhesive stage, which accounts for the quickness of suppuration of these parts in many cases. I have known a violent discharge of pus come on the surface of the urethra only a few hours after contamination. These facts are shown us every day in various inflammations of those parts, and particularly in the gonorrhoea, cold in the nose, lungs, intestines, etc. The matter from such is generally not called true matter, or purulent, but is often so, if not always, having all the characters of pus; however, this will be according to circumstances. Since those surfaces are, in general, secreting surfaces, suppuration would appear to be only a change in the secretion; and I think I have visibly seen, or could visibly trace, the one change gradually leading into the other; the different parts, therefore, of which the pus is composed will not always be in the same proportion, so that the matter will seem to vary from true matter towards that of the common secretion of the part, and vice versa. But this does not alter the position, for it is common to matter from a sore; and even common to our ordinary secretions. If this inflammation, which produced suppuration on those surfaces, becomes more violent, or has something of the erysipelatous disposition, we find that it moves from the suppurative to the adhesive, and throws out the coagulating lymph. I have seen this in the intestines, often on the inside of intestines that had been strangulated in a hernia. I have been able also to produce it on the inside of the vagina of an ass, by injecting a strong solution of corrosive sublimate. But if of the erysipelatous kind, these surfaces will take on the adhesive action immediately or at first. This is evidently the case in what is called the ulcerous sore throat; I have seen it in the trachea ; I have seen it thrown up from the lungs in branches; I have seen it in the pelves of the kidneys, ureters, bladder, and urethra. This is contrary to the mode of action of the erysipelatous inflammation in the cellular membrane and circumscribed cavities, for there it hardly produces adhesions; and when it suppu rates the suppuration takes place first.

* I make a distinction between an internal cavity and a canal; they are very different in their construction; their uses, and also their mode of action in disease are very different. 280 HUNTER ON THE BLOOD. The common inflammation and the erysipelatous would seem to change actionssimilarto the adhesive and the suppurative,according as-they are changed to places of different dispositions, never acting in the same way under the same apparent circumstances, and, therefore, something specifically different. As the adhesive inflammation is commonly excluded from such surfaces in the true inflammation, so of course is the ulcerative in such cases; for it is in general only as a consequence of the adhesive and suppurative having previously taken place, with the confinement of pus, that ulceration becomes necessary; for the ulcerative in such cases is a consequence of a stimulus arising from pressure from within.* In inflammation we seldom pay attention to more than the continued and the universal sympathy; how far the contiguous takes place without adhesions, further than sensation, I am not certain, I believe it never produces inflammation without them; for we may observe, that a testicle shall be considerably inflamed, and the scrotum not in the least affected. The scrotum shall even inflame and slough off, without the testicle being affected till death, or exposure takes place in the tunica vaginalis; then it becomes an exposed or imperfect surface, similar to the opening or application of a caustic in the hydrocele; but I know that contiguous sympathy produces a nervous tenderness or sensibility, expressed by the word sore. Thus I have seen complains in the viscera of the abdomen produce a vast tenderness in the skin of the abdomen; and also complaints of the lungs produce a tenderness in the skin of the chest opposite to the complaint. The remote sympathy sometimes takes place when particular parts are inflamed. The continued is that sympathy which increases the inflammatory space, by which means the inflammation spreads beyond the irritating point. This becomes more a subject of surgery than any

* [It may generally be concluded that the inflammation is of a specific or unhealthy kind, either when coagulable lymph is thrown out in the first instance on mucous canals, as in thrush, croup, diptherite, dysentery, &c, or when, in all other structures, the puriferm secretion is not first preceded by an exudation of lymph, as in erysipelas, diffuse cellular inflammation, purulent depositions after severe accidents, &c. The employment of the term erysipelatous to designate every species of spreading inflammation and almost every deviation from the standard of health is extremely vague, and has been objected to with much propriety by the author (see infra). Whether erysipelas can take place indifferently in any of the structures of the body has been a much-mooted point: certainly the distinctive symptoms will generally if not always be wanting. Even in the mucous membranes, which exhibit so striking an analogy in structure and functions to the skin, there is a maiked difference in the general characters of their inflammatory affections, not to mention that they evince no disposition whatever to travel from one to the other, but generally keep perfectly distinct. The membranes of the brain indeed are often more or less affected in extensive erysipelas of the head and face, but this is rather attributable in my opinion to the near proximity of the sympathizing organ to the scene of inflammatory excitement than to any proper extension of the inflammation itself. The retropulsion of erysipelas, like that of every other external inflammation, is apt to induce inflammation internally, but there is not the least proof to show that this new action has the specific character of the original disease.] FUNDAMENTAL PRINCIPLES OF INFLAMMATION. 281 of the sympathies, because it increases the local complaint, and it takes its peculiarities from the constitution at large, as well as from the nature of the parts inflamed ; as much can be learned from it in an inflammation as from any other symptom. The universal sympathy, or constitutional, is where the whole constitution feels the local diseased action.

§ 5. The natural cause of the Adhesive Inflammation being limited.

As the body is made up of dissimilar parts, whose construction and functions are peculiar to themselves, yet all tending to the benefit of the whole, we find them also keeping themselves distinct in many of their diseases as long as they can ; and if it is a disease somewhat peculiar to the part it will be kept in proportion longer confined. Thus a cancer in the breast will spread faster in the glandular part of the breast than in the surrounding parts which may even be in contact with it. A disease taking place in any part of a lymphatic gland will communicate its disease to the whole of that gland much sooner than to the surrounding cellular membrane. Even a disease common to all parts alike, if it takes place in any dissimilar part, will keep distinct at first. Thus an inflammation in a lymphatic gland is not taken up by the surrounding cellular membrane till the inflammation has made some considerable advancement, and then it begins to inflame. Thus a lymphatic gland shall inflame and the surrounding parts shall not, till other processes besides inflammation are going on, viz., suppuration ; this, however, will be more or less, according to the constitution, for if it has a strong susceptibility for the erysipelatous, the dissimilar parts will more readily sympathize with the seat of the disease. Thus the investing membranes have not this sympathetic connexion with the parts which they either coyer or line ; nor have the parts either covering the investing membrane, or lined by it, any sympathizing affection with it in the adhesive stages of inflammation. Thus the peritoneum is both a lining and a covering, and so is the pleura. If the peritoneum which hues the cavity of the abdomen inflames, its inflammation does not affect the parietes of the abdomen ; or if the peritoneum covering any of the viscera is inflamed, it does not affect the viscera. Thus the peritoneum shall be universally inflamed, as in the puerperal fever, yet the parietes of the abdomen and the proper coats of the intestines shall not be affected ; on the other hand, if the parietes of the abdomen or the proper coats of the intestines are inflamed, the peritoneum shall not be affected. The same principle will lead to distinctions between an inflammation of the lungs and that of the pleura; but I suspect that the reticular or connecting substance, which joins the air-cells of the lungs, has a greater sympathetic affection with the air-cells, or reciprocally with each other, than the before-mentioned parts; and this may arise from the thinness of the air-cells. And it is also 282 HUNTER ON THE BLOOD. upon the same principle that inflammation of the pia mater is seldom continued into the substance of the brain, although the pia mater may be in some degree considered as a continuation of the same vessels. Contiguity of parts does nofcommunicate inflammation. Thus, when an intestine is inflamed the inflammation is not communicated to the peritoneum, lining the abdomen, although in contact; but I have already observed it produces somewhat of a soreness, even to the external touch; but if continuity by adhesions takes place, then inflammation will be continued from the one into the other. The second cause of the limitation of inflammation is simple contact. I have already observed, that exposure of internal surfaces becomes an immediate cause of inflammation; and when it extends further than the surface of exposure, it is then by continued sympathy only, and that a whole cavity, if wholly exposed, will wholly acquire the inflammation ; but we may now observe, that although a cavity is opened and so far rendered imperfect, yet simple contact of its sides renders it perfect again, and sets bounds to the immediate cause. To explain this further, we may observe that there is no such thing in an animal as empty space, exclusive of outlets or reservoirs, which cannot be reckoned internal or circumscribed cavities, for they are perfect by not being such. Every part of the body is either connected by a continuation of one part into that of another, or by simple contact. This takes place equally, either in the common cellular membrane, or in the circumscribed cavities; for if a wound is made either into the cellular membrane, or into a circumscribed cavity, we find that the surfaces of both, beyond the cut edges, are naturally and generally in contact with one another, for without this union by the first intention would not take place, either in circumscribed cavities, or in the common cellular membrane. To explain this position, let me suppose a case. If we make a wound into the cavity of the belly, and in a sound state of those parts, we shall find that every viscus is in contact with some other viscus, and that the whole inside of the peritoneum is in contact with the viscera in general; so that no space is unfilled while this contact of parts remains. If this wound is not allowed to heal by the first intention, still we shall find that no inflammation will take place, or extend further than the attachment of those parts to the cut edges, except what is owing to continued sympathy. If this was not the case, every part of the same cavity must inflame, because every part would be equally imperfect; for if this contact was removed, upon the receiving of the wound, or at any time afterwards, the whole cavity must inflame, because every part is equally under the same predicament with regard to exposure. The same thing would take place in the common cellular membrane if those cells were not (in a natural state) in contact. Inflammation, in case of wounds, would as readily extend over the surface of each cell, as air does through the cavity of each cell FUNDAMENTAL PRINCIPLES OF INFLAMMATION. 283 when blown into it. Now this simple and natural contact of natural parts keeps off the inflammation beyond the cut edges of exposure; and inflammation only takes place at this part to preserve this contact, as also to serve as a basis for the future operations. This, I apprehend, is upon the principle of contiguous sympathy, two surfaces being simply in contact, mutually agreeing not to inflame; or perhaps, more properly expressed, by being in contact there is a mutual harmony which prevents their being excited to inflammation. This circumstance is a reason why we should not attempt to bring circumscribed cavities to universal suppuration, by simply opening them and allowing them to collapse; for we may be pretty certain that union only will take place at the exposed edges of contact, which excludes the general cavity, and which is the reason why the operation for the radical cure in the hydrocele often fails. If, on the other hand, this natural contact of parts did not preserve the whole beyond the cut edges, then we must allow that the cavity is under the same predicament with the cut edges; and if the cut edges inflame, so must the whole. In cases of spontaneous inflammation of circumscribed cavities, we find where this contact is completest, that the inflammation and its consequences are the least; for instance, in the abdomen, in the cases of the peritoneal inflammations, the inflammation is the greatest where the surfaces are not so well opposed to one another, viz., in the angle between any of the two viscera. This fact of simple contact being sufficient to exclude the irritation for inflammation, was well illustrated in a woman who had the Cassarian operation performed upon her, where a wound of eight inches long was made into the cavity of the abdomen to extract the child. After the child was extracted, the wound could not be brought exactly together ; therefore, so far gave rise to a peritoneal inflammation ; but the belly collapsing, and falling on its contents, they all came in contact as before, and the woman living twentysix'hours, gave time for the inflammatory irritation to take place. After death it was found that the intestines were united to the peritoneum all round the wound for about half an inch in breadth, and the surface of the intestines which lay unattached and exposed at the bottom of the wound were inflamed, while every other viscus, as well as the peritoneum, beyond the adhesions, were free from inflammation. , ,., Ulceration does not seem to obey this law so much, and the reason is, that ulceration is a second operation, and is preceded by inflammation, so that pus is brought equally through every part, it equally susceptible of ulceration, which all parts are not, although not depending upon their being similar or dissimilar. Ihus a muscle or artery will not ulcerate so readily as cellular membrane ; but it pus was formed on the inside of an artery, or in the centre of a muscle, they would ulcerate very readily, and the ulceration would not stop or remain stationary, when it came to the cellular membrane, but would go on; if pus, too, be formed in a lymphatic 284 HUNTER ON THE BLOOD. gland, ulceration would go on in the parts between it and the external surface as fast as it did in the gland, if not faster, because inflammation would have gone before, and, as it were, assimilated the parts, and all from this cause, viz., being equally disposed to ulcerate. The cause of the spreading of inflammation is sympathetic ; but the cause of ulceration is immediate.*

§ 6. Of Inflammation—its Stages.

I have given the most simple idea I can form of an injury done to a part, with the natural, immediate, and consequent means of restoration. I have also treated of cases where they become a little more complicated, requiring the aid of art as a substitute for the simplicity of the first. The action of the parts is not necessary in either of these, except that of the blood forming its vessels and other solid parts, and becoming of the nature of the parts in which it is extravasated. But I took notice [1] that the violence done was often so great, or that restoration did not take place so readily, as in all cases to exclude irritation ; we had, therefore, an action in such cases taking place in the parts called inflammation ; and [2] that this action assisted in the restoration by producing an extravasation of the coagulating lymph, which became the second bond of union. I have also stated what may be called the natural tendency to inflammation, to serve as a kind of leading principle. We shall find that inflammation may arise from very different causes, and often without any apparent cause, and that its operations are far more extensive than simply the act of producing union in parts divided by violence; for it more commonly produces union in whole parts or in natural separations, such as the common cellular membrane, large circumscribed cavities, joints, etc., because such surfaces are not naturally disposed to unite, but only in consequence of some uncommon action being produced; and although these adhesions are unnatural, yet that tendency of the parts to admit of this union becomes a species of cure. It is in consequence of the parts taking on, in some degree, the same mode of action

* [Difference of structure has nearly as marked an effect in many instances in resisting the extension of ulceration as it has that of inflammation. This is very little observed in the progress of an abscess towards the surface, because the extension of ulceration in this case depends on the continued presence of the immediate cause, viz,, the distension or pressure from behind, and therefore takes place as it were necessarily ; whereas, when it depends on sympathy alone, as in ulceration of the bowels, stomach, bladder, &c, nothing is more common than to see the muscular fibres clean dissected by the ulcerative process, and pertinaciously resisting its further progress; or should these equally give way to the ulcerative action, still the peritoneal covering (not so thick, perhaps, as a piece of common writing-paper) is interposed, to arrest its further progress, and prevent the faecal contents escaping into the peritoneal cavity. The same fact is also observable in superficial ulcerations of the skin, in abscesses of the lungs, brain, &c. It is very unusual to find the dura mater or pleura perforated in such cases.] FUNDAMENTAL PRINCIPLES OF INFLAMMATION. which divided parts do when brought in contact, that in such cases suppuration is precluded. As inflammation often arises from disease, its salutary purposes are in many instances not so evident, although they may finally take effect; as it likewise takes place in disease, or becomes the ultimate in disease where it did not begin in it, as in the scrofula, cancer, &c, and some indolent tumours; on these accounts, too, its salutary purposes are sometimes not obvious. However, upon the whole, as inflammation is an action produced for the restoration of the most simple injury in sound parts, which goes beyond the power of union by the first intention, we must look upon it in such instances as one of the most simple operations in nature, whatever it may be when arising from disease or in diseased parts. Inflammation is to be considered only as a disturbed state of parts, which requires a new but salutary mode of action to restore them to that state wherein a natural mode of action alone is necessary. From such a view of the subject therefore, inflammation in itself is not to be considered as a disease, but as a salutary operation consequent either to some violence or some disease.* But this same operation can and does vary : it is often carried much further, even in sound parts, than to accomplish union, producing a very different effect, and forming a very different species of discharge from the former; instead of uniting and confining the parts, rather separating and exposing them, which process is called suppuration, and varies with circumstances. However, even this in sound parts leads to a cure, although in another or secondary way; and in disease, where it can alter the diseased mode of action, it likewise leads to a cure ; but where it cannot accomplish that salutary purpose, as in the cancer, scrofula, venereal disease, &c, it does mischief. This operation of the body, termed inflammation, requires our greatest attention, for it is one of the most common and most extensive in its effects of any in the animal body: it is both very extensive in its causes, and it becomes itself the cause of many local effects both salutary and diseased. It has its different stages, in which it produces more immediately its different effects, which are local, such as adhesions, suppuration, and ulceration, and often death in the part inflamed, together with secondary complaints which are universal, as fever, nervous affections ; and when in parts that cannot heal, or in constitutions which are too weak, the hectic fever, next dissolution, or universal death. However, by its forming those adhesions, it often precludes the necessity of suppuration ; and also entirely prevents many local diseases where probably suppuration would be the consequence if such adhesions had not taken place, with all the train of consequences of suppuration, such asabscesses, fistulae,diseased bones,&c, which are prevented by it. It is also one of the modes of action

* [This is too great refinement. The definition of disease ought certainly to include all such deviations from the natural state as either produce suffering or endanger life.] 25 286 HUNTER ON THE BLOOD. in many specific diseases, and in morbid affections proceeding from poisons. Inflammation is not only occasionally the cause of diseases, but it is often a mode of cure, since it frequently produces a resolution of indurated parts, by changing the diseased action into a salutary one, if capable of resolution. By these extensive powers inflammation becomes the first principle in surgery. In one point of view it may be considered as a disease in itself, where it takes place without any visible cause, and it may be looked upon as an increase of the mischief when it is a consequence of some injury; but in either case it is a sign of powers, and of necessary powers : for if a part under the influence of such irritation as should naturally excite inflammation had either no powers, or no disposition to exert them, the consequences would be much worse, for mortification would probably take place. I intend at present to consider the most common causes and effects of inflammation, together with the end proposed by nature in producing it, and the use to which it can be applied in surgery. It becomes therefore necessary, first, to begin with describing its most simple forms, together with its general effects, and then to particularize as I proceed. Inflammation has several well-marked local peculiarities by which it is distinguished. I shall call by the name of inflammation whatever produces the following local effects, viz., pain, swelling, and redness, in a given time, and these dependent on, or the effects of, one immediate cause. Inflammation appears capable of arising from three causes, which may be called remote. First, from some accidental force applied to a part, making a wound or bruise which cannot recover itself unless by inflammation. Such violence at least is naturally capable of exciting it. Secondly, from some irritation which does not destroy the texture of parts, but simply the natural actions, as many irritations, such as pressure, friction, heat, cold, blisters, pungent applications, and often fevers of every kind. Thirdly, from a particular disposition in parts themselves, as boils arising spontaneously, without the constitution having been preconcerned ; so little so, as to have given the idea that such inflammations were healthy. Each of these will be of a kind peculiar to the constitution; but from whatever cause inflammation arises.it appears to be nearly the same in all, for in all it is an effect intended to bring about a reinstatement of the parts nearly to their natural functic-ns. Inflammation may first be divided into two kinds as first principles, viz., the healthy and the unhealthy. The healthy probably consists only of one kind, not being divisible but into its different stages, and being that which will always attend a healthy constitution or part, is rather to be considered as a restorative action than a diseased one, and would rather appear to be an effect of a stimulus than an irritation. The unhealthy admits of vast variety, (diseases being almost numberless,) and is that which always at- FUNDAMENTAL PRINCIPLES OF INFLAMMATION. tends an unhealthy constitution or part, and will be according to the kind of health in that constitution or part, but principally according to the constitution ; however, many parts naturally have a tendency to run into inflammations of particular kinds. Most of those arising from the nature of the constitution are, I conceive, in most cases, if not in all, called, although erroneously, the erysipelatous inflammation; which will be further taken notice of. The simple act of inflammation cannot be called specific, for it is a uniform or simple action itself; but it may have peculiarities or specific actions superadded. Inflammation is either single or compound : it may be called single when it has only one mode of action in the part inflamed, as in its first stages ; compound, when attended with another mode of action, or when it produces other effects. Inflammation is capable of producing three different effects, viz., adhesions of the parts inflamed, suppuration in the parts, and ulceration of those parts ; which I have called the adhesive, the suppurative, and the ulcerative inflammation. The last, or ulcerative, is, properly speaking, only a secondary effect of inflammation, not being performed by the same vessels; however, it is possible it may keep up inflammation, as it always keeps up a species of violence, viz., a destruction of the parts. The two first do not take place in the same vessels at the same time, but succeed one another, although all the three effects may exist at the same time in the different parts of the same inflammation. I have placed the adhesive first in order, although it is not always so; for, with respect to the priority of those three actions of inflammation, it depends principally upon the nature of the parts, together with the degrees of violence of the inflammation. To explain this more fully we shall first divide the body, respecting inflammation, into two parts, viz., the cellular membrane, or the body in general, together with the circumscribed cavities, as belonging to the first; and then all the outlets of the body as the second. We shall treat of each according to the nature of the parts, and of the inflammation joined, and observe their effects, which will show that the common effects of one, as to priority, may be changed into those of the others, and become second or third, according to the nature of ihe parts, the inflammation, and its degree of violence. We may observe that inflammation, but more especially the suppurative, in the first order of parts, more readily takes place nearer to the surface of the body than in parts more deeply seated ; and as a proof of this observation it has been formerly observed that tumours, and even extraneous bodies, will make their way from some deeper-seated part to the skin, but no inflammation shall take place till they arrive near the skin. But this circumstance will be more fully described when I treat on suppuration. It does not seem necessary that both surfaces which are to be united should be in a state of inflammation for the purpose of 288 HUNTER ON THE BLOOD. effecting a union: it appears only necessary that one should be in such a state, which is to furnish the materials, viz., to throw out the coagulating lymph, and the opposite uninflamed surface accepts simply of the union. Nor is it even necessary that either surface should be in a state of inflammation to admit of union: for I just observed that extravasated blood produces a union [union by the first intention] without inflammation, and we often find adhesions of parts which can hardly be called inflamed. Thus a truss applied to a rupture will produce adhesions, as has been observed, although it may sit very easily. In describing inflammation it will be found that the principal theory of inflammation will be introduced in the adhesive stages ; for in the first-stated parts it appears only preparatory to the suppurative either in preventing or promoting it. When inflammation takes place in the first order of parts it is commonly the adhesive; but it will be according to circumstances whether the suppurative or the ulcerative follows first. That either the one or the other should follow seems to arise in many cases from an increase of the inflammation ; but it sometimes happens that the suppurative takes place almost immediately, and probably from two causes : the first is the intensity of the inflammation, its exoeeding the adhesive almost immediately ; the second, an inflammation of a different kind, where the adhesive makes no part of the inflammation, and suppuration takes place in the first instance. I suspect that the erysipelatous inflammation has very little of the adhesive in its nature, and therefore probably these inflammations are in some degree of this nature, and go into suppuration without adhesions. In some cases ulcerations must take place prior to suppuration, as when an inflammation happens on a surface, viz., the skin, as, for instance, in a chancre, and with such violence as is necessary for suppuration to take place, then ulceration must begin first, so as to expose internal surfaces for suppuration ; but in the parts of the second order, viz., internal canals or ducts, it is the suppurative inflammation which most readily takes place first; but if carried further the adhesive follows, as will be more fully explained hereafter. When it is an inflammation of the first order of parts, the suppurative succeeds the adhesive, and the ulcerative may be said to be an action superadded to the suppurative, arising out of effects produced by the first, now becoming new causes, the suppurative naturally taking place in the time of the first, and the ulcerative in consequence of the suppurative, which has called forth the action of another system of vessels, the absorbents ; all of which may be reckoned as three different modes of action arising from the first irritation or cause. The adhesive as also the suppurative inflammation, either in the first or second orders of parts, with their varieties, may have a principle superadded which does not in the least alter their inflammatory mode of action, which still continues to go on. This principle is some specific disposition from scrofula or poison?, as the venereal, small-pox, &c. FUNDAMENTAL PRINCIPLES OF INFLAMMATION. 289

These three different modes of action, viz., the adhesive, the suppurative, and the ulcerative, when carried on perfectly, are generally the effects of a good constitution, seldom attending the unhealthy: they are what I would call common inflammation. I have already observed that common inflammation either takes place in parts that constitute the largest part of an animal, which are all the circumscribed cavities, all the cellular membrane, and the substance of every part, the two last of which are the most universal ; or upon internal canals or outlets, which are, in common, only excretory ducts. I have also observed that whenever any extraneous matter is to be discharged, whether already existing, as matter already formed, or a ball lodged, &c, or only preparatory to its formation, such as inflammation that has a disposition to suppurate, the inflammation is always greatest and extends furthest on that side next to the skin; for instance, suppose that a man is shot in the thigh, that the ball passes through to within an inch or two of the opposite side, and that it has not deadened any part for an inch or two of the last part of its passage so as to allow this part to unite, we shall find if that ball excites inflammation it will not be along its passage, where we should (without knowing the principle) have mostly expected it, but the inflammation will commence on that side next to the opposite skin that has not in the least been hurt. If the ball passes quite through, and a piece of cloth is carried in, which lies in the middle between the two orifices; if the passage is pretty superficial, say only an inch distant from the skin where the cloth lies, but which is two or three inches from either orifice, we shall find that the inflammation for its exit will not lead to either orifice, but directly across to the skin.* As the adhesive inflammation precedes the suppurative in every part of the body except the outlets, as was observed, and the suppurative commonly precedes the ulcerative, excepting on an external surface, the propriety of following likewise this order of nature in treating of them will appear evident, especially as each succeeding inflammation is in some measure illustrated by that which has gone before.

§ 7. Of the different degrees and different kinds of Inflammation.

Inflammation will in general be in proportion to the exciting cause (in which may be included the mischief done), the constitution, and the nature of the part; in all which, as there is great variety,

* [That is, the ball or the piece of cloth produces the greatest inflammation in that part where the stimulus of its presence is most felt, which is in the immediate spot where it is lodged, while the external parts being more extensible than the internal, the inflammation and ulceration necessarily take the former direction. This fact of the greater extensibility of the external parts removes much of the mystery which has been generally thought to attach to the approach of abscesses or foreign bodies to the surface of the body. Distension as pressure must produce very nearly the same mechanical state of parts.] 25* 290 HUNTER ON THE BLOOD. so must there be in the inflammations. The degrees of inflammation will be more in the adhesive than in the suppurative, for the adhesive may have all the degrees of violence between the most slight inflammation and suppuration; but the suppurative is a more fixed or determined quantity, for when got to a certain point it takes a new action, and inflammation ceases. However, we have not always inflammation producing suppuration when it has arrived to a certain degree of violence, for in some it often goes beyond that point which would produce it in others, and in such cases there is no disposition for suppuration, and it seems to become stationary, for neither has it any disposition for resolution. Spontaneous inflammations which are to suppurate are more violent than those inflammations arising in consequence of an operation or accident, which also must produce suppuration; and those inflammations from either operations or accidents, if they have not produced death in the part operated upon, are more violent and of greater extent than those where death in the part has been produced. The inflammation of a boil or abscess is more violent, and commonly more extensive than that in consequence of a cut, or even an amputation of a leg. The inflammation in consequence of a cut or amputation of a leg will be more violent than that from a gunshot wound, or from the application of a caustic, which produces death in the part, and even although more parts have been destroyed by these means; neither do specific diseases, except the gout, produce so violent inflammation, nor are they commonly so painful as what I have called the common inflammation. It may appear not to be an easy matter to account for all those differences: however, it is possible that in the spontaneous inflammation there is more occasion for inflammation than suppuration ; the inflammation being the only action which is necessary to produce the ultimate effect, as, for instance, in the gout: in this disease the inflammation is the only thing necessary for its action, and the inflammation runs much higher than many others do which produce suppuration.* The spontaneous inflammation arises often from disease, which probably makes the parts more susceptible of inflammation. When inflammation arises from the irritation of death in a part, let the cause of that effect be what it will, whether mechanical, as in bruises, gunshot wounds, &c, or by chemical means, as caustic, &c, the inflammation is late in coming on, and in comparison with the others gentle when come on. However, in many bruises, even where the death of parts has taken place, we have inflammation

* It is a curious circumstance in the gout, that although it is attended with all the common effects of the adhesive inflammation, as considerable swelling, &c, which swelling must arise from extravasation of the coagulating lymph, yet adhesions do not seem to be the intention, for none are produced ; the lymph is in general taken up, and chalk-stone or tophaceous matter [urate of soda] put in its place. FUNDAMENTAL PRINCIPLES OF INFLAMMATION. 291

quick and violent; but then the living parts have also suffered, and have suffered much more than if simply wounded. In many bruises we also have inflammations quick and violent, even where death has been produced in a part; but then death does not take place in all the hurt parts, as in many gunshot wounds, such as those attended with fractured bones, in which the surrounding parts were only hurt so far as to bring on irritation and not death. If caustics do not act with vigour they will irritate so as to bring on the inflammation sooner than if they had killed the part quickly.* Irritating substances, when of no specific kind, produce inflammation sooner than other visible causes of inflammation. If of a specific kind, then the time^sort, and violence [of inflammation] will be according to that kind. But irritating applications must be continued for some time to produce violent inflammation. These differences are easily accounted for; quick death does not irritate the part killed, and the contiguous living part, not being itself hurt, is only irritated to get rid of the dead part. A wound is a quick irritation of a living part, so that it inflames more readily and more violently according to the quantity of irritation ; but that cannot be of long standing, as nature sets about procuring relief. But when irritating substances are applied, the part inflames quickly, according to their power of irritation; and if they are continued, nature is not allowed to relieve herself, but is constantly teazed, by which means the inflammation becomes also violent. I need hardly mention that fever is often the cause of local inflammation: we see this happen every day. These causes, and of course the inflammation, are of two kinds: one which maybe called accidental, as inflammation arising in consequence of common fever; the others are more determined, depending upon the species of fever, which may be called specific, as the small-pox, chicken-pox, &c. These inflammations, in consequence of fever, are commonly supposed to be critical; but I very much doubt the truth of this opinion. The small-pox and chicken-pox are, perhaps, the strongest instances of an appearance in proof of this opinion, and perhaps the measles as a critical inflammation might be produced as another; but I believe that it is peculiar to these diseases to form inflammation and sores. We must allow, however, it is not absolutely necessary, even in them, that abscesses should be formed, viz.. the pock, to lessen or carry off the fever; for the specific fever in them cannot exist beyond a certain time, even although no eruption appears. But I think that in the cases of the small-pox, chicken-pox, and the measles, those diseases often prove the contrary to that which is supposed to be the case; for we have large abscesses as often formed after those diseases as after any other, which are com-

• [This is also well exemplified in the application of ligatures for the removal of piles, nsevi materni, enlarged tonsils, &c. The pain and inflammation consequent on such operations are immensely increased by not tightening the ligature with a decree offeree sufficient entirely to cut off all vascular communication.] 292 HUNTER ON THE BLOOD. monly supposed to be the settling of the fever in this part, but which are equally accidental with those from common fever, and therefore we cannot suppose that those abscesses are critical in such diseases, because they are either common abscesses or scrofulous; for no one disease can have two distinct and different critical inflammations. In further confirmation of my opinion, those inflammations are found to be not in the least of the nature of the disease which produces them, so little so in most cases as to be truly specific of another kind, viz., the scrofulous. Now we certainly find it difficult to conceive one universal specific disease, as the small-pox, &c, producing a local one of another specific disposition to cure the first, or terminating in another disease, whose mode of action is totally different; and the more so when we see that the same local diseases can and do arise from every kind of fever. To ascertain this fact, therefore, we are to look out for that disposition, or that mode of action, common to all fevers which are capable of producing this effect, with the disposition of the constitution or of the part at the time; and we shall find that this kind of inflammation depends upon the constitution and part at the time; and not upon any peculiarity in the fever, as is also the case with the small-pox eruptions, viz., they partake of the constitution. This common principle in fever, of producing local inflammation, is the simple fever itself abstracted from every peculiarity. A fever, in all cases or of all kinds, is a disturbed action, like inflammation itself, which may be joined with any specific mode of action, and this disturbed action will always be according to the constitution, even when joined with any specific qualify. The inflammatory fever is, perhaps, the most 'simple, because" it is a simple fever on a constitution having no peculiarity of disposition. The putrid fever (as it is called) is perhaps no more than the same fever upon a constitution that has a peculiarity of action under that disturbance, and therefore it proceeds according to that peculiarity. This is well illustrated in specific diseases; for instance, in the small-pox. The small-pox produces a fever, viz., a disturbed action, joined with the specific; and although this action is produced by the same poison in two different persons, yet the one shall be the true inflammatory, and the other the putrid, the erysipelatous, &c. Now the same poison can have but one mode of irritating, abstracted from its poisonous quality, and this one mode produces fever; and it also can have but one mode of irritating in respect of its poisonous quality, but that fever, abstracted from its poisonous quality, will be according to the nature of the constitution at the time, the poison being capable of producing nothing but a fever joined with its specific poison, and that specific quality takes place equally on every kind of constitution, the poison itself having no power of affectincr the constitution in one person differently from that of another; ft can onlv act, in a greater or less degree, according to the susceptibility of the person for such irritation. Now, since every fever, FUNDAMENTAL PRINCIPLES OF INFLAMMATION. 293 whether common or specific, is equally capable of producing local inflammation, which may be carried the length of suppuration, and as it cannot with any degree of reason be called critical in specific fevers, we have no reason for supposing that those suppurations are critical in the common fever, or in those fevers which are of no specific kind. . It was a leading doctrine of Boerhaave that inflammation consisted in an obstruction of the minute vessels, in consequence of too great a spissitude of the fluids, and his practice consisted in seekin- for attenuants; but this theory seems to be almost entirely exploded. This was certainly too confined an idea of all the causes of inflammation, and reduced all inflammations to one species. 1 he only distinction between inflammations must have arisen irom the nature of the obstruction, if there could be any ; but this could never account for the action of many specific diseases and poisons. It was also too mechanical. If they had said that any obstruction to the natural actions of a part which could stop the blood's motion in it became a cause of inflammation, they would not have been so materially wrong as to a possible cause of inflammation. It has been a°s much laboured, on the other hand, to show that the cause cannot on any occasion be obstruction in the blood s motion through the small vessels; but I will venture to say'that any cause which can obstruct the motion of the blood for a given time will become the cause of inflammation; for either the cause of the obstruction itself, or the blood being retained iri the smaller vessels for a certain time, will either irritate or unite the part, or where it irritates will throw the vessels into such actions as naturally arise out of an extraneous irritating cause but not an increased motion of the blood behind, to drive on the obstructed blood through these vessels, as has been supposed. It will excite Sat action which in the end produces suppuration in order^ get rid of the extraneous matter which was the cause of the obstrucion such as pressure on external parts, or the obstructing matter self which is to be reckoned extraneous. But though pure mflamma ion i rather an effort of nature than a disease, yet it always Sues disease or disturbance, inasmuch as there must be a prevTou mo bid or disturbed state to make such effort necessary All inflammations attended with disease have some specific_ quality which simple inflammation has not; and in such cases it is the 7pheclficSq3ity which is the disease, and not^the, ,n^ --tion f such constitutions or parts as are c4aPabl%oft/^enf0^ed upon as adhesive and suppurative inflammation are to be looked upon as

d fferen't operations well, it is exactly similar to common healthy different opei* irritation as above described were to 'STcon" Ua" on or parts' in another state than th.. of health, ^should then ^haveEither the adhesive or suppurafve mflam. 294 HUNTER ON THE BLOOD. mation taking place, but most probably some other, such as the erysipelatous or scrofulous, according to the nature of the constitution or parts at the time. This state of health in a constitution is so remarkable that we see in the time of the symptomatic fever, when nature would seem to be universally disturbed, a kindly or benign inflammation going on, and kindly suppuration; which shows that this fever has no specific tendency to wrong action, the constitution being only disturbed by sympathizing with a local injury, but not capable of giving or reflecting back upon the part inflamed a diseased disposition or action. And this is so remarkable that such inflammations as seem to affect the constitution by sympathy only, which is commonly either from extent, quantity, or the seat of it being a part essential to or connected with parts belonging to life, go on as kindly as they do in a small inflammation, as a boil, which does not affect the constitution in the least. Indeed fever is a good symptom when equal to the injury, and of the same kind with the local affection, when that kind is good. Let us take an amputation of a leg as an example, which produces something more than a disturbed constitution, for there is a great loss of a substance to that constitution, which, abstracted from the violence, would probably produce considerable effects till the constitution became accustomed to the loss; but even with all this loss we often find that a healthy inflammation shall come upon the stump, and a kindly suppuration take place, while the symptomatic fever lasts. In many cases also it still keeps its ground even when affected by many specific irritations which are foreign to it; and nearly in the same manner as when affected by a common irritation, which will only rouse that constitution into action, but not alter it, having only the specific difference added, so that the parts will go readily through the adhesive orsuppurative inflammation ; the specific being only an attendant on this healthy action: this we see plainly to be the case in the healthy small-pox* and the lues venerea in its first stages. But, on the contrary, if the constitution is such at the time as would readily fall into an unhealthy inflammation, from common irritation or accidental violence, then it will also fall into that state when irritated by a specific irritation foreign to the constitution, such as the small-pox, which in this case will run into the confluent kind.* There are many constitutions which have a tendency to specific diseases that, when injured by fever or any constitutional complaint, readily produce the specific inflammation in such parts of the body

* [Dr. Gregory has justly observed that the mildness or malignancy of smallpox does not depend so much on badness of constitution or differences in the contagion as on idiosyncrasy ox peculiarity of habit; for as there are certain constitutions which suffer more than others from lead, mercury, and the venereal poison, so there are certain systems unusually irritable under the operation of the variolous virus. If this observation is just, and there seems no reason to doubt it, it will materially affect the soundness of Mr. Hunter's conclusions.] FUNDAMENTAL PRINCIPLES OF INFLAMMATION. 295 as have the greatest susceptibility for any specific action; or if such parts are affected by any local violence, the parts affected will not go through the healthy adhesive inflammation, nor will they enter into the healthy suppurative inflammation, but will fall into the specific inflammation peculiar to the habit: such is the case with an erysipelatous habit. Or if a specific inflammation has already taken place, any violence done to it, when already beo-un will increase that disposition and action, which we plainly selto'be the case with the scrofula, because this disease can and often does arise from such a cause alone. Besides the constitution producing such effects, there are many parts of the body which have a greater tendency to some specific disease than the constitution in general; which particular parts will fall into these specific inflammations more readily than others, either upon the constitution being affected, or a violence committed upon themselves: for instance, many parts of the body have a greater tendency to fall So the scrofula than others, and these will fall into that mode of action when injured, either by means of the constitution or from accident; except the constitutional complaint is such as to be a specific for the scrofula, which I can easily conceive it may. In the cancer also, if the disease has previously taken place, then the tendency of an injury is to exasperate and increase it. But there are specific irritations which do not affect either the part or the constitution, as a common irritation, but aftect them in a way peculiar to the irritation, altering at the same time both the parts affected and the constitution from a healthy state to an unhealthy one of its own kind. This seems to be the case with the plague,perhaps with the putrid and jail distempers in a less degree forfwhatever be the kind of constitution which they attack, they always reduce that constitution to their own kind : it is not a healthy opSon going on and the specific superadded, as in the healthy small-pox,g&c.° However, even the plague has its degree of power over a constitution, some being much more easily, and of course more violently, affected than others. This change in these cases, SpeciX"nthe first, is often so great that the constitution hard y ever recovers it, so that the patient dies; which we have observed above is not the case with many other specific diseases or poisons, as the small-pox, &c, for this disease makes no change in the con-

StUFrom ^halt^Ld it must appear that the irritations which are Capable of producing those inflammations may be either simple as those which produce0 the adhesive, or producing with * other modest rctoS, as either suppuration or ulceration ; and also either ol the above modes of action may be joined with some of the

SpeHLteaCwe°may conclude that irritations, of whatever kind, either produce an inflammation peculiar to the constitution or the nature of the parts, according to the irritating cause, as in the plague ; and where U is according to the constitution, that many specific irnta- 296 HUNTER ON THE BLOOD.

tions may be added without altering the nature of the inflammation itself, and that they only determine its situation, extent, duration, &c„ according to the specific disposition added, provided the constitution be healthy; but if the constitution be unhealthy (whether affected with erysipelas, putrid fever, or plague), and the specific disease be superadded, it will be a mixture of both, that is, it will be a specific inflammation set down upon a constitution of a peculiar kind, and partaking of the character of both, and those specific properties will not be so distinct, or so well formed, as when they appear in a sound constitution. If the constitution has a susceptibility to be putrid, and the smallpox attacks it, the inflammation will be the small-pox joined with the putrid mode of action of the constitution, which will affect the mode of action peculiar to the small-pox, and destroy the specific difference of the inflammation belonging to the small-pox : the pustules will spread, not suppurate, and look livid according to the putrid disposition. These constant effects, peculiar to the constitution, may be changed from the one to the other just as the constitution changes, for the small-pox may begin upon a healthy constitution, in which they will be distinct or circumscribed ; but if the constitution becomes diseased, they will spread : and if the constitution takes a healthy turn again, they will begin to contract to their specific distance again.*

* The knowledge of these facts is of great service in the cure of many specific diseases; for, whatever the specific disease may be, we are always to treat the patient in one respect according to the general nature of the inflammation ; and if we have a specific remedy we are also to join that with the other; but if we have not a specific remedy, we are then only to take up the disease according to the constitution. Let us illustrate the foregoing propositions by example. The first case is explained by the venereal disease in the form of a chancre: the venereal matter produces an inflammation and ulceration according to the nature of the specific disease and the constitution; if the constitution is perfectly healthy, then the effects are the suppurative and specific disease joined; the limits of both are confined according to the constitution and the nature of the specific disease, for the inflammation and ulceration never extend beyond the specific affection; but if the constitution is such as readily to fall into the erysipelatous, then it becomes the erysipelatous and specific joined; and although the extent of the specific affection is limited, that of the erysipelatous is not: the consequence of which is that it spreads over the whole prepuce, and often the whole skin of the penis. In this disease, under such circumstances, we are led to the method of cure: for although we have a medicine for the venereal inflammation, yet bark is to be given for the erysipelatous; the quantity to be given is according to the predominancy of the one or the other. The effects of this practice are very striking: for as the erysipelatous inflammation lessens it becomes more confined in its limits and, as it were, drawn into the original point; and when it becomes truly suppurative and venereal, its limits then are brought within the specific distance. The second case is explained by the small-pox. The variolous matter in healthy constitutions produces the suppurative and specific inflammations: the specific is limited, and directs the suppurative ; but if the erysipelatous comes on, the suppurative ceases; it then spreads along the surface, uniting inflammation with inflammation, and producing the confluent small-pox. We have no specific remedy for the small-pox, nor can we readily have any for FUNDAMENTAL PRINCIPLES OF INFLAMMATION. 297 Many people are much more susceptible of inflammation than others, even of the common kind, and those probably may be reckoned simply irritable. In such it is more violent, and in such it is more apt to spread, the surrounding parts being ready to actor sympathize with an action to which they are prone; continued sympathy more readily takes place in such cases :* but his is not universal for we find many very considerable inflammations con fined to the part irritated, and in such instances continued sympathy is not great; only the part irritated takes up the action

Vi0Thellterm or idea of inflammation may be too general, yet it is probable [hat it may form a genus in which there is a number o species or it may be more confined in its classification, and be reck Ted a 'specie^ containing several varieties.f These are, however,

a disease which cures itself; our business then is to cure the erysipelatous, if possible, and leave the constitution to cure the; sPeclfic/ . fa , or d If 1 * This one might illustrate by a piece of paper being €ither dry or aa p drv then ink wifl not spread, it will be confined to its point, but itdampin wi

proceeds to notice the different causes which give rise, win tie primary form called varieties, and these he g.oups togetne^ unoe b heads, viZ., structure, posmon, climate;age, &cn te «£ *an • P^ differences of constitution or of exciting cause °" ™e ol"e ' , incidentally necessarily imply a deviation ftoj?*Jh^y Jand ari/he 7™° J rf hig J_ noticed; although it was impossible ^^.^"^XleTal points, when these happerience, should not occasionally'expatiateon' 3*ure Xcft is the method °f pened to be of importance. By this ™e,^^^~U^jCiy deduced out of ihe crystallographer, the "^.^P^^^ia^^er imethod would have

S^^oSTinSS % ^.ofUe this as a„y defect of

the present treatise. inflammation is incapable of any strict 1 believe, further, that the subff^'X™0^ some fixed circumstance nosological classification, pr.nc.pa ly from the want at ■ ^ ^^^ of leading importance to serve as thebzss.of asystem y hlegrn0nous or to use such epithets as sthenic or f1^'^^ terms serve to express a erysipelatous, scrofulous or carbunculoiis bee use these, tern wh_ch ^ ^ resemblance of the existing m^mmation tojme^ertan ?j ^ ^ ^.^ understood; but it would be in v«>n to at^mp^oamnge wou]d ^ ^^ of inflammation under any two or more of the e^heaas Carmichael Smith, fication founded on difference c.tissue as 6« F£P«J 7 tQ different kind8 of be at all more practicable, because t!* »™ ™u" 0CJur in different kinds of

^::^i^^^^^^- L™one to an*ther-In fact 298 HUNTER ON THE BLOOD. so connected among themselves that we cannot justly understand any one of the species or varieties without forming some idea of the whole, by which means, when treating of any one, we can better contrast it with the others, which gives us a clearer idea both of the one we are treating of and of the whole. So far as it appears to be necessary to take notice of the different inflammations, as illustrative, they may be comprehended in five divisions; although I must own that if we take in all the specific diseases which produce inflammation, such as the venereal disease in its different forms, the gout, &c, they may be without number. However, many of them produce very much the same appearance and effects with those which are of no specific kind. The specific is of no particular kind, but only the cause; and the specific effect is a something superadded. The present, viz.. the adhesive, with its different effects, as suppuration, I shall consider as one. The cedematous, which comes nearest to the adhesive, forms a second division. The erysipelatous, [a third], the carbuncle [a fourth], and that which leads immediately to mortification [a fifth]. There is another inflammation, very like chilblains [Erythema nodosum ?], which is not very lively and is often in blotches, some the breadth of a shilling, others of the breadth of half-a-crown, and even broader, etc. This inflammation certainly arises from irritable debility; the blotches look more of a copper colour, and the skin over them is often diseased. All, except the first, have a kind of affinity to each other: although I think the oedematous has the least affinity to the three last, and many vary so as to make it difficult to say to which species the varieties belong. There are a great many other inflammations, but which arise from some specific cause, as the gout, scrofula, &c, or poisons ; but as these do not explain, or illustrate by contrast, the adhesive or suppurative inflammation, I shall not give the outlines of them here, except just to mention the particulars of the gout as an inflammation. The action of the complete gout has all the characters (while it lasts) of the true inflammation, and which may be called the inflammatory action of the gout; but it has many singularities attending it which attend no other inflammation, and which of course become some of its specific characters. The inflammation of the gout is very different from the adhesive and suppurative in its sensation. It seldom throbs; it is a pricking, cutting, and darting

there is no other practicable mode of viewing the subject but that of the author, which is to consider healthy inflammation as the standard, and the degree and kind of deviation from this standard as the specific and distinguishing characteristic of individual inflammations. Of all the modifying circumstances, with the exception perhaps of specific causes, it must be admitted that none has greater and more permanent influence than that of texture: but constitutions will sometimes predominate over texture, and the specific nature of the cause over both. Mr. Hunter, in his own masterly manner, has traced the influence of these various circumstances, and especially of texture, in modifying inflammation, in which may be distinctly traced the germs of those brilliant views which were afterwards so successfully developed by the illustrious Bichat.] FUNDAMENTAL PRINCIPLES OF INFLAMMATION. 299 pain; besides which there is a pain which feels as if the inflamed parts were all moving, and in that motion there is pain; therefore the action, which is the cause of the pain, must be very different, and is most probably from the action of the vessels, not from their distension, as in the suppurative inflammation. It probably comes on more quickly than any other. Its violence is probably greater, in duration it is probably the most uncertain, and its going off is quicker than of any other inflammation. Its shifting from one part of the body to another is probably in some degree" peculiar to itself, and it leaves parts in a state which no other inflammation does. Without entering further into the nature of this disease than saying it is an act of the constitution I shall describe some of its visible effects, which of course can only ~ observed when it falls on an external part, and when it doe it i most commonly on an extremity, more especial yon the lower, but sometimes on the upper, and still more commonly the exreme.parts of the extremity in either the upper or the lower; and its principal It m the extremity is a joint. P Vhen it falls on internal par s^t is most commonly the stomach, which is only supposed by its effects or symptoms/from its being transferred, and from the, mode ol ?elieTPIt attacks also the bfain, producing deli™^dine»^e loss of the natural and accustomed feel of the body, incessant sleepiness &c, which is also known by the above circumstances. When it faUs o'n other parts, either externally or **»"$*£»£ so much determined on what part it is most apt to fall. It■ »™*™ falls either on the lungs or muscles of respiration, the throat, testi des urethra, producing a discharge, &c, on the anus, forming piles; which can on^y be knoln to be gSut by collateral cjrcn-Unces Why the extremities, the stomach, and brain, should be similar in susceptibility to take the gouty action from the constitution s not easily accounted for. I should be inclined to suppose that its SLta on7 Stomach or brain are not similar to thoseo»*e ex

5ie^ the ^^s-^r^^^^ It '. 1st probabrXt may be called a true specific inflamma ion, L it nroduces the same immediate effects in every constitution,

of that kind, but may'uuu inflammation of and wppumtion ^&$ZJw£fon; the inflammation fhalSre l^period11 and "then lea?e the extremities in a mueh 300 HUNTER ON THE BLOOD. better state than it found them. Although the inflammatory action ofthe gout is attended with great pain, yet I think it is not so tender as the true inflammation is : a part may be violently inflamed, and yet it may be handled or squeezed; the nerves are not in such a state of irritation: its consequent effects are very different from that of the true inflammation, for instead of entire resolution it gives the disposition to the inflamed parts to fill the joint, or whatever parts have been affected, as, for instance, the cellular membrane with chalk.* However, chalk is not necessarily an effect of the gouty inflammation ; for in a gouty habit we have chalk formed were there never had been any gouty inflammation, yet it is singular it should attack such dissimilar parts as the skin, ligaments, &c. It has not only no tendency to suppuration, as an immediate effect of inflammation, but it leaves the parts in a state not easily excited to inflammation: the chalk shall remain for years without producing inflammation, and seldom produces it at all but from quantity; and when the interior surfaces are exposed they hardly take on common inflammation and suppuration, healing more readily than a sore of the same magnitude from any other cause: even a joint shall be exposed, yet common inflammation shall not come on, nor shall it suppurate ; only a watery fluid shall come out, bringing with it the chalk occasionally, and it shall heal up kindly. It is probable that the gout is not always an act of the constitution, but that parts may be so susceptible, or rather disposed, for this action that they may immediately run into it when deranged. If this notion be well founded, then it may be a question whether this local affection relieves the constitution for the time from any susceptibility for such an action. It may be disputed whether the following are all inflammations or not. They often arise from the same causes: accident, for instance, produces all of them. They have certainly many characters in common, although not always the same result. The vessels becoming enlarged, there is an extravasation, pain, and a separation of the cuticle, but seldom a formation of matter, although there sometimes is, which happens when they have at first more of the adhesive state; and there is a circumstance which I think is common to them, namely, a red streak passing from the inflamed part generally towards the trunk, although not always in this direction. In common language they are called erysipelatous, although very different, the erysipelatous being one of the best marked inflammations of any. I do not mean to treat of these but in a general way, not even when considering the method of cure. It is probable there is no specific distinction between any of these inflammations but what

* [The experiments of Wollaston have shown that these tophaceous depositions consist principally of urate of soda, combined with a little urate and phosphate of lime. The most remarkable fact, however, connected with the appearance of gouty concretions, is the coexistence or alternate deposition of uric acid from the urine: so that a paroxysm of gout is not unfrequently known to pass off bv a copious secretion of this acid from the kidneys.] y FUNDAMENTAL PRINCIPLES OF INFLAMMATION. 301 arises from the constitution or the parts, for we find them all proceeding from what may be called the same accidental cause, which therefore cannot produce anything specific ; the distinctions in the mode of action of the inflamed parts being occasioned by a peculiarity in the constitution, or the nature of the part itself; but probably in the constitution. . . . It has been supposed that the different species or varieties of inflammation arise from the difference in the nature of the part inflamed ; but this is certainly not the case ;* for it it was, we should soon be made acquainted with alUhe different inflammations in the same person, at the same time, and even in the same wound : for instance, in an amputation of a leg, where we cut through skin, cellular membrane, muscle, tendon, periosteum, bone, and marrow, the skin should give us the inflammation of its kind, the cellular membrane of its kind, the muscles of theirs, the tendons of theirs, the periosteum, bone, marrow, &c.,of theirs; but we find it is; the same inflammation in them all: it is the adhesive in them all if the parts are brought together, it is the suppurative if the parts are exposed. I shall at present only take notice of the four last,t as 1 mean to treat more fully of the first, which cannot be so completely understood without seeing the distinctions. [1.] What I would call the oedematous inflammation is when the extravasated fluid is water; it has very much the appearance of the adhesive, and probably comes the nearest to it of any, being of a scarlet colour, but much more diffused. The fluid extravasated, being principally the serum, renders the swelling more diffused than even the inflammation itself; it is very painful, or rather sore, but there is not so much of the throbbing sensation as in the adhesive inflammation ; it appears to be only on the surface, but most probably goes much deeper; for in such cases the extravasated fluid is in too large quantity to be furnished by the cells of the cutis alone; but in this we have not the same guide as in the adhesive, viz., the swelling and inflammation corresponding with each other. The difference between this inflammation and the adhesive arises, I conceive, from the principle of inflammation acting upon a dropsical disposition, which is always attended with weakness; whereas a m-eater degree of strength would have produced the adhesive inflammation under the same cause or irritation; and what makes me conceive this is, that in many cases of anasarcous ^gs we have exactly this inflammation come on from distension, which adds to the extravasation of the serum, as well as in most cases of scarifications of oedematous parts to evacuate the water. When this inflammation takes place it is much more lasting than the adhesive and I believe seldom or never produces suppuration ; but ii it should run into this stage it is more general, and the whole cellular mem-

+ WarneC the species of inflammation referred to at p. 297, viz., the cedematout, erysipelatous', carbunculous, and eloughy inflammations.] 302 HUNTER ON THE BLOOD. brane in the interstices of parts is apt to mortify and slough, producing very extensive abscesses, which are not circumscribed. [2.] The erysipelatous inflammation is very peculiar, and most inflammations that are not of the true adhesive and suppurative kinds are called so, although probably they do not in the least belong to it; and this may arise more from the want of terms than the want of discrimination. This inflammation often arises spontaneously, or in consequence of a low or debilitating fever. It often arises from accident, but then it is commonly a secondary inflammation, although not always: for the first shall have gone off, and when suppuration was to take place it shall have come kindly on, but afterwards the erysipelatous shall take place. This may be called a remote inflammation, and is in this respect somewhat similar to the locked jaw. It is more commonly a cutaneous inflammation than situated in the deeper-seated parts, although in some constitutions every inflammation, wherever it exists, will most probably be of this kind; however, the skin appears to be most susceptible of it, because it will spread over a prodigious surface of skin, while it does not affect even the cellular membrane underneath, at least not commonly. There is an inflammation which attacks internal canals which is classed with the erysipelatous, but how far it is the same I do not know ; it is certainly not the suppurative, and as almost every other inflammation was formerly called erysipelatous, this has been supposed to belong to this kind of inflammation. The inflammation I am speaking of is more common to the throat than any other part, often going down the trachea. Whatever it is, it may be considered in some of its effects to be in direct opposition to the adhesive and the suppurative inflammations ; for where the adhesive most readily produces adhesions, there the erysipelatous does not, as in the common cellular membrane; and where the adhesive seldom takes place, excepting from extreme violence, there this inflammation (if erysipelatous) has a tendency to produce adhesions, as in canals or outlets; it also opposes, in some degree, the suppurative, in being backward in producing suppuration even in those places where suppuration most readily takes place, such as canals and outlets, for there, as above observed, it more readily throws out the coagulating lymph. Whatever the inflammation may be, it is certainly attended with nearly the same kind of constitutional affection. The fever in both appears to be the same, viz., accompanied with debility, languor, etc. The extravasation in consequence of the erysipelatous inflammation is not so great as in either the adhesive or the oedematous ; nor is it of that kind which produces adhesions between the parts inflamed, which in this inflammation would commonly be unnecessary, as it seldom produces suppuration, but is attended with very bad consequences when it does. It appears to support itself by continued sympathy, for it commonly begins at a point and spreads, while it shall be getting well where it first began. This cannot be merely constitutional; for if it was, the parts already in- FUNDAMENTAL PRINCIPLES OF INFLAMMATION. 303 flamed could not recover, if its increase in new parts arose from the constitution; but it gives the idea that when the parts have once gone through this action that they lose the disposition and becomehealthy. This property is not peculiar to this inflammation, the ringworm has this peculiarity, as also many cutaneous ulcers.* This inflammation is more common in the summer than in the winter, more especially in hospitals ; and I think takes place oftener after wounds on the head than any other. I have often seen it begin round a wound, on the scalp, extending itself over the whole head and face ; the eyelids being very much swelled, the ears thickened, and it has advanced to the neck, shoulders, and body, creeping along both arms, and terminating at the fingers' ends; that which attacks the body often goes along the body to both thighs, down the legs, and terminates at the ends of the toes; and while this is going°on, it is as expeditiously cured behind, and the skin peels off the cured parts. However, this is not always the case; it often stops, and where it proceeds so far, it is commonly becoming milder. This inflammation, when it runs along the skin, has a determined edge, not losing itself gradually and insensibly in the skin beyond, as in the true adhesive, and indeed most of the inflammations: the skin feels as if only a little thickened, and not so pliable; for by passing the finger along the sound skin to the inflamed we feel an evident difference. The colour of the skin is of a darkish red. When it goes deeper than the skin into the cellular membrane it often suppurates; but then I suspect it is not the true erysipelatous, for in such cases it commonly produces mortification in the cells, by which air is let loose; this gives a strange feel, neither of fluctuation nor crepitation, and as there are no adhesions the matter finds an easy passage into the common cellular membrane, increasing the same kind of suppuration wherever it comes ; and as mortification is a consequence of these inflammations, putrefaction ensues, and the discharge becomes very offensive. Whether this difference in the effect of the inflammation arises from the nature of the parts, I will not pretend to say. This effect takes place about the buttocks and side of the anus oftener than anywhere else, as indeed does common inflammation and suppuration. This inflammation commonly begins with fever, lowness of spirits, prostration of strength, loss o"f appetite, &c.: but it commonly does not last long, and the inflammation shall spread even when the fever is gone off, but then it is not so violent. When it produces suppuration in the cellular membrane it is often dangerous,

* There appear to me two ways of accounting for this: one is, that the whole skin is very susceptible of such action, and readily goes on with it by continued sympathy, and the part having gone through the action, like the small-pox, &c, loses the disposition, and the action ceases. The other is, that the inflammation is such as to contaminate while it spreads, but when it has once acted it is cured as above observed. If this last be a true solution, then the right practice would be to stop its progress by destroying the parts beyond it. 304 HUNTER ON THE BLOOD. both from the disease itself and the consequences of the matter diffusing itself much further. This effect frequently takes place when this inflammation attacks the buttocks or parts near the anus, and often proves fatal. In such cases, as the sores seldom ulcerate, they should be opened early, for the matter either gets into the cellular membrane from the want of adhesions, or it separates parts that are only attached, as the periosteum from the bone, muscles from muscles, &c, whereas the true suppurative ulcerates briskly, which therefore should not be opened early, but allowed to burst. Many inflammations on the skin which come to suppuration have something of the erysipelatous disposition, for we see them increasing the circle of inflammation, the cuticle separating, matter forming underneath from the cutis, and the sore healing in the centre; they perhaps begin like a pimple, but spread in that way, to the breadth of a sixpence, shilling, or crown-piece; such often takes place on the fingers. [3.] The inflammation that produces the carbuncle is of a different nature from any of the former; it is stationary with respect to place, and is pretty much circumscribed, even forming abroad, flat, firm tumour; it begins in the skin almost like a pimple, and goes deeper and deeper, spreading with a broad base under the skin in the cellular membrane; and although considerably tumefied, yet this does not arise from the extravasation of coagulating lymph producing adhesions which are to retain life, for the very cells into which it is extravasated become dead. It produces a suppuration, but not an abscess, somewhat similar to the erysipelatous when the inflammation passes into the cellular membrane, for as there are no adhesions the matter lies in the cells where it was formed, almost like water in an anasarca ; but still it is not diffused through the uninflamed cellular membrane, as in the erysipelatous, for it appears to extend no further than the inflammation : one would almost imagine that there was a limitation to the extent, beyond which this species of inflammation could not go, and at these limits the adhesive inflammation took place to confine the matter within the bounds of the carbuncle. A diffused ulceration on the inside for the exit of the matter takes place, making a number of openings through the skin. There are generally more carbuncles than one at the same time, a great number succeeding each other, which would almost seem to produce each other in this succession : they are commonly more on the trunk of the body than anywhere else. However, I have seen them on the head, and sometimes on the extremities, although but seldom. They are more commonly on the posterior part of the body than the anterior. This inflammation attacks more beyond the middle age than at it, and very few under it. It is most common in those that have lived well. I never saw but one patient of this kind in an hospital. It appears to have some affinity to the boil; but the boil differs in this respect, that it has more of the true FUNDAMENTAL PRINCIPLES OF INFLAMMATION. inflammation, therefore spreads less, and is more peculiar to the young than the old, which may be the reason why it partakes more of the true inflammation. As death is produced in a great deal of the cellular membrane, and I believe in it only, except the skin giving way, which I believe is by ulceration principally, it becomes a question whether this mortification arises from the nature of the inflammation, or rather from the matter being confined in the cells of the cellular membrane. I rather suspect the latter; for I find that if this matter escapes from these cells and comes into uninflamed cells, it produces mortification there. This is like the urine, for whenever the urine escapes into the cellular membrane it there produces mortification; the colour of the skin is at first more vivid than afterwards, for it becomes of a purple colour.* [4.] Inflammation often produces mortification or death in the part inflamed. This commonly takes place in old people that are become very much debilitated, and chiefly in the lower extremities. I suspect it to be somewhat similar to the carbuncle, viz. principally in those who have lived well, although not so much confined to them as the carbuncle; however, it take in the young, where great debility has been produced from disease, especially those diseases that have debility as a principle, such as what are commonly called putrid fevers; but the situation of these is not so determined, and in such inflammation hardly takes place without an immediate exciting cause, as the application of blisters, &c. Death in a part sometimes takes place almost immediately without inflammation; but this is not to the present purpose. Where mortification succeeds inflammation in the extremities, especially in elderly persons, there is often an early separation of the cuticle which forms a blister, filled with a bloody serum; and we shall observe dark brownish spots, which consist of extravasated blood in the true cutis, and which shall at last blister, and then the cutis forms a slough.t Such inflammations have little of the adhesive tumefaction in them, but more of the oedematous ; are not clear or transparent, but rather of a dusky red. As the colour of the inflamed parts shows something of its nature, it is to be observed that it is different in all these inflammations from that of the true adhesive : and as we have reason to believe that the circulation is quicker in the adhesive inflammation than is natural, and that the colour arises from this cause,

* [Probably the scarlet colour may in some measure arise from the salts of the urine. Afterwards, as the urine putrefies, ammonia is evolved, which changes the natural colour of the blood to a deep black.] f [See Lecons Orales de CUnique Chirurgicale, par M. Dupuytren. According to this gentleman, the spontaneous, dry, or senile gangrene (which is here principally referred to) is generally the consequence of spontaneous arteritis and obliteration of the principal vessels. According to Cruveilhier, the same effect may be produced by arterial inflammation induced by direct experiment on living animals.] 306 HUNTER ON THE BLOOD. we may suppose that the motion of the blood in these is languid. and that it assumes the venal appearance even in the arteries. In most of these four inflammations there is an appearance that often arises, which is a reddish streak commonly passing from the inflamed parts towards the source of the circulation, but not always in this direction, sometimes just the contrary; and this is more certain when it happens to take place in an extremity, because there we know the course of all the vessels better; but it does not always arise from the part inflamed. I have seen this last species of inflammation attack the toes, and red streaks run up the foot terminating about the ankle, while there were several arising on the fore part of the leg just below the knee. They often make a network on the leg, and are frequently a forerunner and an attendant on mortification. They seldom go further than a blush in the skin, seldom thicken, but are more of the oedematous kind; however, we sometimes find hard cords running from sores and inflammations, but these are commonly deeper-seated, and I have suspected them to be veins. As a proof of this, I have seen the superficial veins of the leg have the skin red over them, similar to those above described, and the veins have felt hard under the finger. These reddish streaks are supposed to be absorbents, becoming inflamed by their carrying a stimulating fluid. I arrwapt to suppose them to be absorbents, but I do not conceive that this effect arises from absorption. If it arose from such a cause it should be uniform; the cause should always exist when the effect takes place. It is first to be observed that it only takes place in certain constitutions, in which absorption one way or other explains nothing; and I find, upon observation, that this effect shall be coeval with the inflammation where no suppuration has taken place. I have even seen it arise from accident, prior to the possibility of inflammation taking place, viz., in the time of the pain arising from the immediate effects of the accident: this was in the finger, from the prick of a clean needle, which had been for some time piercing new buckskin leather; the glands in the armpit were sore; sickness, attended with its usual symptoms, such as oppression, was nearly as immediate. Its direction from the source of the circulation is another strong proof of its not arising from absorption, and its taking place at some distance is also a corroboration of the same opinion. Another strong circumstance in favour of this opinion is that the morbid poisons do not produce this effect, where we know absorption has taken place. Thus the venereal seldom if ever produces it. The hard cord passing from the prepuce along the upper part of the penis I do not conceive to be of this kind. In the small-pox after inoculation it has been observed, but I imagine it was only in the above-mentioned constitutions. I could conceive it to arise in the plague, if there was any local disease. I am therefore rather apt to attribute this appearance to the irritation running along the lymphatics, more especially in such constitutions ; and as we do not allow the veins to be absorbents, their THE ADHESIVE INFLAMMATION. 307 being affected must be supposed to arise from the same cause.* Whenever we see this effect we may, in some degree, form an opinion of the kind of inflammation, and that it is not the most favourable. CHAPTER III.

THE ADHESIVE INFLAMMATION.

I shall begin by treating of the nature and effects of what I have called the adhesive inflammation, as well as giving a proper idea of it. I shall also open the way to a clear understanding of the many phenomena which attend the suppurative inflammation. But as inflammation does not produce one effect only, but several, and as most of them take place about the same time, it is difficult to determine in the mind which to describe first. Inflammation in most cases appears to begin at a point; for at the very first commencement all the local symptoms are within a very small compass; and they afterwards spread according to the violence of the cause, the disposition in the parts for inflammation, and the nature of the surrounding parts themselves, which susceptibility in the surrounding parts may be either constitutional or local. This is so much the case that inflammation shall come on at once in a fixed point, giving great pain, and which shall be soon followed by tumefaction. This is also the case with those inflammations which arise from accident, for all accidents are confined to fixed and determined limits; but the inflammation which follows is not; it spreads over a large extent; yet the inflammation is always the greater the nearer it is to the first fixed point, and gradually becomes less and less in the surrounding parts, till at last it is insensibly lost in them. This spreading of the inflammation is owing to continued sympathy, the surrounding parts sympathizing with the point of irritation; and in proportion to the health of the surrounding parts and constitution this sympathy is less; for we find in many states of

* [See paper On Absorption by Veins in next volume, and On Inflammation of the Veins at the end of this volume. The symptoms and phenomena of inflammation of the absorbents and inflammation of the veins are analogous in many respects, and very often occur together, particularly after parturition. The particular conditions which dispose to these inflammations are very imperfectly understood, but, in general they undoubtedly point to a broken down and highly irritable state of the constitution. Inflammation of the absorbents is the most frequent of the two, and very often is the first symptom of an attack of erysipelas, the inflammation passing outwards, as it were, with great facility, and extensively spreading on the skin. It is probably from the interposition of the lymphatic glands preventing the circulation of pus, that inflammation of the absorbents is so much less fatal than that of the veins.] 308 HUNTER ON THE BLOOD. parts, and many constitutions, that there is a disposition to this sympathy, and in such the inflammation spreads in proportion.*

§ 1. Action of the Vessels in Inflammation.

The act of inflammation would appear to be an increased action of the vessels ;f but whatever action it is, it takes place most probably in the smaller vessels, for it may be confined almost to a point where nothing but the smallest vessels exist. The larger vessels may be considered as only the conveyers of the materials, for the smaller to act upon and dispose of according to the different intentions; however, inflammation in apart is not only an action of the smaller vessels in the part itself, but in the larger vessels leading to it. This is proved by a whitlow taking place on the end of a finger; for although the inflammation itself shall be confined to the end of a finger; and the inflammatory sensation or throbbing be situated in this part, yet we can feel by our hands, when we grasp the finger, a strong pulsation in the two arteries leading to the inflamed part, while no such pulsation can be felt in the other fingers ; and if the inflammation is very considerable, the artery, as high as the wrist, will be sensibly affected, which proves that the arterial system is at that time dilating itself, and allowing a much larger quantity of blood to pass than is usual. This is probably by continued sympathy. Where the inflammation affects the constitution, the vessels of the system rather contract, and keep as it were stationary, which stationary contraction is more or less according to the state of the constitution. In strong, healthy constitutions, whose powers are equal to the necessary actions, or in parts that affect the constitution less, this contraction is less and less stationary. The very first act of the vessels when the stimulus which excites inflammation is applied, is, I believe, exactly similar to a blush. It is, I believe, simply an increase or distension beyond their natural size. This effect we see takes place upon many occasions ; gentle friction on the skin produces it, gently stimulating medicines have the same effect; a warm glow is the consequence, similar to that of the cheek in a blush; and if either of these be increased or continued, real inflammation will be the consequence, as well as excoriation, suppuration, and ulceration. This effect we often see, even

* [The disposition to spread may depend on many causes, as the nature of the part affected, the quality of the exciting cause, or the state of the constitution at the time. Where it depends on the constitution, it may be affirmed almost certainly that the nervous system is much debilitated and that locally there is a defective power of effusing coagulable lymph; a circumstance of which Mr. Jamea has ingeniously availed himself to form the basis of his classification of inflammations.] t It may be here remarked, that the action^of vessels is commonly supposed to be contraction, either by their elastic or muscular coats; but I have shown that their elastic power also dilated them, and I have reason to believe their muscular power has a similar effect. THE ADHESIVE INFLAMMATION. 309 where considerable mischief has been done; and I believe it is what always terminates the boundaries of the true inflammation. A musket-ball shall pass a considerable way under the skin, perhaps half-way round the body, which shall be discovered and traced by a red band in the skin, not in the least hard, only a little tender to the touch; and it shall subside without extending further. This appearance I shaJUUerm a blush; for although this may be reckoned the first act-t>f "inflammation, yet I would not call it inflammation, having produced a lasting effect. I should rather say that inflammation sets out from this point, and that afterwards a new action begins, which is probably first a separation of the coagulating lymph, and the throwing it out of the vessels. The parts inflamed appear to become more vascular; but how far they are really so I am not certain; for this appearance does (at least in part) arise from the dilatation of the vessels, which allows the red part of the blood to go into vessels where only serum and coagulating lymph could pass when they were in a natural state; and till the newly-extravasated substances become vascular, the effect is most probably owing wholly to the above cause. This incipient enlargement of the vessels upon the first excitement of inflammation is satisfactorily seen in the following manner. Make an incision through the skin on the inside of the upper part of a dog's thigh, three inches long. By pulling the cut edges asunder, and observing the exposed surface, we shall see the blush or ash-coloured cellular membrane covering the different parts underneath, with a few arteries passing through it to the neighbouring parts. But in a little time we shall see these vessels increasing in size, and also smaller vessels going off from them that were not before observable, as if newly formed or forming; the number and size shall increase till the whole surface shall become extremely vascular, and at last the red blood shall be thrown out in small dots on the exposed surface, probably through the cut ends of the arteries that only carried the lymph before. This surface will become in time more opake and less ductile. Parts inflamed, when compared with similar parts not inflamed, show a considerable difference in the size of the vessels, and probably from this cause bring an increased number to view. I froze the ear of a rabbit and thawed it again: this excited a considerable inflammation, an increased heat, and a considerable thickening of the part. This rabbit was killed when the ear was in the height of inflammation, and the head being injected, the two ears were removed and dried [see PI. II.]. The uninflamed ear dried clear and transparent, the vessels were distinctly seen ramifying through the substance ; but the inflamed ear dried thicker and more opake, and its arteries were considerably larger. In inflammation of the eye, which is commonly of the tunica conjunctiva, the progress of inflammation may in part be accurately observed, although not so progressively as in a wound. The contrast between the red vessel and the white of the eye, under this 27 310 HUNTER ON THE BLOOD. coat, is very conspicuous; and although we do not see the vessels enlarging in this coaf, yet we see the progress they have made; the white appears as if "it was becoming more vascular, and these vessels larger, till at last the whole tunica conjunctiva shall appear as one mass of blood, looking more like extravasated blood than a congeries of vessels, although I believe it is commonly the last. From these circumstances it must appear that a much larger quantity of blood passes through parts when inflamed than when in a natural state,* which is according to the common rules of the animal ceconomy; for, whenever a part has more to do than simply to support itself, the blood is there collected in larger quantity. This we find to take place Universally in those parts whose powers are called up to action by some necessary operation to be performed, whether natural or diseased. As the vessels become larger, and the part becomes more of the colour of the blood, it is to be supposed there is more blood in the part; and as the true inflammatory colour is scarlet, or that colour which the blood has when in the arteries, one would from hence conclude either that the arteries were principally dilated, or at least, if the veins are equally distended, that the blood undergoes no change in such inflammation in its passage from the arteries into the veins, which I think is most probably the case; and this may arise from the quickness of its passage through those vessels. When inflammation takes place in parts that have a degree of transparency, that transparency is lessened. This is, probably, best seen in membranes, such as those membranes which line cavities, or cover bodies in those cavities, such as the pia mater, where, in a natural state, we may observe the blood-vessels to be very distinct. But when we see the blood-vessels fuller than common, yet distinct in such membranes, we are not to call that inflammation, although it may be the first step, as we find to be the case in the first action of the vessels in consequence of such irritation as will end in inflammation. As it may not, however, be the first step, there must be other attending circumstances to determine it to be the very first action of the vessels in inflammation, for as that appearance may either belong to a briskness in the circulation in the part at the time, or be the very first step in inflammation, their causes are to be discriminated by some other symptom. They are both a kind of blush, or an exertion of the action of the vessels; but when it is an effect of an inflammatory cause, it is then only that the inflammation has not yet produced any change in the natural structure of the parts, but which it will soon do.f What the action is, or in what it differs from the common action of the

* [Recent microscopical investigations have demonstrated the error of this opinion, as will be shown moie fully presently.] t When this appearance is seen anywhere after death it should not be called inflammation, even although we knew it was the first action of inflammation; for as we are then only looking out for the causes of death, or the symptoms prior to death, we are only to look out for such as can be a cause, and not lay hold of those that cannot possibly be a cause, which those first actions cannot be. THE ADHESIVE INFLAMMATION. vessels, is not easily ascertained, since we are more able to judge of the effects than the immediate cause. However, it is probably an action of the vessels, which we can better observe than any diseased action in the body, for we can observe the state in which the arteries are, with their general effects : we feel also a different temperature respecting heat, yet the immediate cause may not be ascertainable. The vessels, both arteries and veins, in the inflamed part are enlarged, and the part becomes visibly more vascular; from which we should suspect, that instead of an increased contraction, there was rather what would appear an increased relaxation of their muscular powers, being, as we might suppose, left to the elasticity entirely. This would be reducing them to a state of paralysis simply ; but the power of muscular contraction would seem to give way in inflammation, for they certainly dilate more in inflammation than the extent of the elastic power would allow : and it must also be supposed that the elastic power of the artery must be dilated in the same proportion. The contents of the circulation being thrown out upon such occasions, would, from considering it in those lights, rather confirm us in that opinion; and when we consider the whole of this as a necessary operation of nature, we must suppose it something more than simply a common relaxation; we must suppose it an action in the parts to produce an increase of size to answer particular purposes; and this I should call the action of dilatation, as we see the uterus increase in size in the time of uterine-gestation, as well as the os tineas in the time of labour, the consequence of the preceding actions, and necessary for the completion of those which are to follow. The force of the circulation would seem to have some share in this effect, but only as a secondary cause ; for I could conceive a part to inflame, or be in a state of inflammation, although no blood were to pass. As a proof of this, we may observe, that by lessening either the action of the heart, or the column of blood, inflammation is lessened ; and I may also observe, that we have an increased pain in the inflamed part in the diastole of the artery, and a part inflamed by being gently pressed is made easier. Thus a person with an inflammation in the finger will find relief by gently pressing it in the other hand. These are strong proofs that it is not a contractile action of the muscular ceat of the vessel; for in such a sensible state of vessels, if they contracted by their muscular power, the pain would be in their systole; for we find in all muscles which are in a state of great sensibility, from whatever cause, that they cannot act without giving great pain. Thus an inflamed bladder becomes extremely painful when expelling its contents; an inflamed intestine in the same manner. I should say, therefore, that in inflammation the muscular coats of the arteries do not contract. Whatever purpose this increase of the size of the vessels may answer, we must suppose it allows a greater quantity of blood to pass through the inflamed part than in the natural state, which 312 HUNTER ON THE BLOOD. supposition is supported by many other observations. The part inflamed, I have already observed, becomes to appearance more vascular than when in the natural state, and it is probable that it is really so, both from new vessels being set up in the inflamed part, as well as from the new and adventitious uniting substance becoming vascular. Besides, the vessels of the parts are enlarged; so that the red blood passes further than common, which increases those appearances. But the brain appears to be an exception to these general rules ; for in all diseases of the brain, where the effects were such as are commonly the consequence of inflammation, such as suppuration from accidents, I never could find the above appearances; the brain may, perhaps, go directly into suppuration, as sometimes the peritonaeum does ; but its slowness of going into suppuration after the accident would make us suppose, tl priori, that there was sufficient time for adhesions to form.*

* [In an inquiry into the proximate cause of inflammation, two principal considerations occur: first, as to the state of the capillary circulation, and, secondly, as to the influence of the nervous system. 1. When the web of a frog's foot, or the transparent mesentery of a warmblooded animal, are viewed in the field of a good microscope, and at the same time irritated, effects very different are observed to ensue in different cases; but in all instances where inflammation is well established the vessels are observed to be increased in number as well as size, and the course of the blood to be much retarded. The evidence upon this point is so universal, precise, and satisfactory, as to render any detail upon the subject quite unnecessary and any doubt upon the question a mere excess of scepticism. (See Treatise on Inflammation, by Dr. C. Hastings, p. 67. Hist, des Inflam., par M. Gendrin, ii. 475, (1453 et seq.) Lectures on Inflam., by Dr. J. Thomson, p. 61. Treatise on Febrile Diseases, by Dr. W. Philip, 3d edit. ii. 17. Kaltenbrunner, op. cit. See ante, p. 142.) It would appear, however, that there is a great difference between actual inflammation and that precedent state of erubescence which is excited by slight stimulants, or which bounds the outer circumference of an inflamed part, a difference which has not always been attended to, and which in many instances has led to mistakes on this subject. At first the effect of stimulation is generally to contract the small vessels and to accelerate the circulation ; but as soon as inflammation is unequivocally established, the circulation is invariably retarded. In severe cases indeed the retardation amounts to a complete stasis, although in the surrounding parts the blood is observed to flow with more rapidity than usual. Arguing from these facts, Dr. Hastings and others have drawn the conclusion that debility of the capillaries is the cause of inflammation; or in other words, that the increased action of the vessels, consequent an the application of stimuli, exhausts and impairs their irritability, and gives rise to their subsequent dilatation, followed on the other hand by an increased action of the larger vessels; so that, according to this gentleman, " Inflammation consists in a weakened action of the capillaries, by which the equilibrium between the larger and smaller vessels is destroyed, and the latter become distended:" while the restoration of an inflamed part is supposed to be effected by the capillary vessels being so excited, and the larger vessels so far weakened, by the preternatural action of the latter, that the two are again brought into correspondence and proportion to each other. The objections to this theory are sufficiently obvious, as it not only places the two extremities of the vascular system in opposi'ion to each other, without any apparent cause, but makes the recovery of inflammation to depend upon the reaction of the larger vessels, which, if we may judge from the effect of remedies, or from the common sense of the case, should appear to be one of the most certain means of increasing it. Besides, why the larger vessels should be excited by the THE ADHESIVE INFLAMMATION. 313 $ 2. Of the Colour, Swelling, and Pain of Inflamed Parts.

[Colour.']—The colour of an inflamed part is visibly changed from the natural, whatever it was, to a red. This red is of various hues,

debility of the smaller, or the latter recover themselves from their debilitated state by the excitement of the larger, is not pretended to be accounted for; not to mention that every physiological fact is strongly repugnant to the notion of an action, essentially reparative, like that of inflammation, being dependent on debility for its principle. The other most prevailing opinion on this subject is that which was adopted by our author, viz., that inflammation is an increased action of the natural powers of a part attended with an accelerated circulation. The grounds for this opinion are as follow : 1. That whena part has more to do than simply to support its own life, an increased activity of the circulation becomes necessary; as, for instance, in the growth of the stag's horn, the enlargement of the vessels of the uterus during gestation, and the augmented supply of blood to secreting organs during the period of their activity. 2. That the arteries and capillaries visibly enlarge in size and increase in number in inflammation exactly as they are observed to do when the healthy functions of any part are unusually exerted. 3. That as, under ordinary circumstances, the heat and sensibility of parts are in proportion to the quantity of blood going to these parts, so it is reasonable to conclude that the same effects, observable in inflammation, are dependent on the same causes. 4. That inflamed parts bleed more copiously than those which are uninflamed, and that .the redness returns more rapidly after pressure than is observed to happen in parts which have been stricken with cold, and are. consequently congested. 5. That the returning veins from an inflamed part are more distended than naturally, which perfectly accords with the observation made by Mr. Lawrence that when venesection is simultaneously performed on both arms, one of which is inflamed, the blood which flows from the inflamed side, in a given time, is twice and sometimes three times as great as that which flows from the sound side. 6. That periodic determinations of blood consequent on increased activity of function are apt, when excessive either in degree or duration, to terminate in inflammation, in the same manner exactly as great or prolonged constitutional excitement from exercise or mental causes may terminate in fever. 7. That the arterial colour of the blood in inflamed parts depends (as Mr. Hunter supposed) on the rapidity of its transmission through the parts, which does not allow sufficient time for the usual changes to take place; an effect, however, which it seems more reasonable to refer to the perverted state of the vital functions. 8. That the pulsatory and throbbing pain of inflammation indicates an increased local activity, just as any sudden or great exertion of muscular power occasions throbbing of the whole system. The augmented volume and stroke of the pulse, and the increased impetus with which the blood is projected from an inflamed vessel when divided, are additional proofs of the same kind. 9. That as the application of stimuli, ex vi termini, excites an unusual activity of function in all the organs of the body, it seems unreasonable to assign a sedative effect to these agencies where they occasion inflammation. 10. That the causes of inflammation, immediate as well as predisponent, are of such a nature as to give increased vigour to most of the operations of the ceconomy, as on the other hand the nature of the remedies employed is precisely of that kind which is known, from experience, to be best calculated to diminish strength as well as to reduce action. 11. That the ordinary functions of an inflamed part, and sometimes of the whole system, are suspended and as it were concentrated on the process of reparation, agreeably to what is observed to happen when other important operations are carried on in the animal body. These reasons seem sufficient to lead to the conclusion that inflammation is an act in which, if there is not increased power, there is at least increased action. The capital objection to this theory is, that the circulation is demonstratively 27* 314 HUNTER ON THE BLOOD. according to the nature of the inflammation ; if healthy, it is a pale red ; if less healthy, the colour will be darker, more of a purple,

retarded, and sometimes completely arrested,in inflammation; an objection which is partly removed, however, by the consideration, that although retarded in the most inflamed parts, it is accelerated in the parts adjacent. The statement, however, is objectionable on other accounts. It makes increased action, in parts professedly contractile, to consist in dilatation, for which we have no authority, and whim obviously confounds congestion with inflammation; besides, dilatation can only influence the circulation by giving increased effect to the heart's action; an effect, however, which by no means universally follows ; and in regard to the larger arteries the same consequences must ensue, for it has been proved by Dr. Alison, that instead of their contractility being increased, as the hypothesis supposes, it is certainly impaired (4th and 5th Rep. of Br. Assoc). In the sense, therefore, in which the author understood the term, increased action certainly does not take place, although in another sense it certainly must. Probably the effect of inflammation is to approximate the structure of an inflamed part to that of a gland, requiring, on the one hand, a slow circulation, in order that the important offices of reparation may be carried on; and on the other hand, an extensive supply of the vital fluid as aliment to this function. It is at least remarkable, that the whole internal arrangements of glands, as well indeed as of the whole capillary system, seem designed to retard the circulation, while the most prominent symptom of inflammation, and that which forms the only unequivocal proof of its presence, is the slowness of the circulation and the extraordinary quantity of effusion which is poured out. Inflammation, however, is an act which involves all the functions of a part. The blood itself is affected. It loses its globular structure, and the globules are observed to lose their repulsive properties, and either to agglomerate together, or to adhere to the sides of the vessels. At first it is generally redder than usual, but afterwards it assumes various shades of brown or yellow, until at length, when suppuration is fairly established, it has the character of pus, which some have been able to trace, as it slowly moved along the vessels, until it finally exuded on the surface. (Gendrin, op. cit., ii. 47!J. 1457, 1458.) Along with these appearances are sometimes observed irregular flocculi, floating in a transparent fluid, which have the appearance of ragged portions of lymph, or decolorated and broken-down globules of blood. As soon as the inflammation begins to subside, the globules reappear, and the current of the circulation is slowly reestablished; but should the inflammation increase still further in violence, the blood then entirely loses its red colour, complete stagnation of it takes place, and the part becomes gangrenous. More or fewer of these changes invariably attend inflammation, which cannot therefore be supposed to consist in a simple alteration of the circulation, but principally of those vital affinities subsisting between the vessels and their contents which are the peculiar attributes of life. As soon as inflam nation is established, an increased secretion takes place from the cells of the cellular membrane, which at first is limpid and colourless, and contains little albumen, but becomes more yellow and more charged with albumen as the inflammation advances. Then it becomes semi-gelatinous, depending on a small admixture of fibrin with it. Bloody strise and puncta now appear in it, the fibrin becomes more abundant, blood is poured out in a pure state, and finally pus is formed. Those successive degenerations are fully exhibited in the section of an inflamed part, beginning from the circumference to the centre, and correspond precisely with the effusions which take place from the surfaces of inflamed membranes, being in fact so many degenerations of the natural secretions of the parts. From these facts, therefore, it is obvious that inflammation induces a new state of the secretory function, and that all the results of inflammation are the consequence of this modification, an inference which perfectly coincides with Mr. Hunter's views of suppuration, although it is opposed to those of M. Gendrin, who supposes that the various matters effused in inflammation are spontaneously con- THE ADHESIVE INFLAMMATION. 315 and so on till it shall be a bluish purple, which I took notice of in the short sketch of the peculiar inflammations; but the parts invertible into pus, without the aid of the proper vessels. (Op. cit., ii. 471. 1447, 1448.) 2. The facts which relate to the influence of the nervous system in the production of inflammation are neither numerous nor precise, which is probably the reason why this part of the subject has received less attention than the state of the capillaries. There can be no doubt of the general analogy which exists between the reparation of the accidental lesions of the frame, and the ordinary nutrition of the body, and also that the functions of secretion, excretion, absorption, sensibility, and the due venalization of the blood, are all more or less modified and affected by the process of inflammation; so far, therefore, as these functions are dependent on or liable to be affected by the nervous system in a state of health, so far it seems reasonable to conclude that they are similarly affected in the process of inflammation. 1. The circulation and nutrition of parts are greatly impaired by a paralysis of the nerves, while, from the best observation of physiologists, it appears that deficiency or imperfect development of the normal organization is exactly correspondent to the deficiency or imperfect development of the corresponding portions of the spinal marrow. 2. The experiments of physiologists have demonstrated that the functions of secretion and excretion, and the general offices of a part, are greatly dependent on the integrity of the nervous system. The urine is not secreted after decapitation, nor the gastric juice after the division of the eighth pair of nerves. 3. The nutrition of the body is affected by various influences of the mind, which can only be supposed to operate through the medium of the nerves. 4. Intense pain often ushers in the inflammatory attack, and precedes every other apparent symptom. So also hysterical and sympathetic pains, obviously depending on some distant source, often excite inflammation, while the operation of cold can only be explained on the same principle. From facts of this kind some have inferred the invariable precedence of some disturbance of the nervous system. 5. Metastatic inflammations are plainly referrible to the same cause, unless they are to be explained on the humoral pathology. Thus also the appearances of local inflammation, especially of the exunthematous eruptions, are often preceded by constitutional rigors and fever, which plainly evince an antecedent disturbance of the nervous system. 6. Blushing, the contraction of the extreme capillaries from fear and other causes, and the effects produced by the sudden crushing of the nervous centres, are proofs of the influence which the nervous system has over the circulation. 7. Division of the fifth pair of nerves gives rise to inflammation and consequent destruction of the globe of the eye. Similar effects have been known to ensue from compression of the fifth pair within the cranium (Med. Gaz., i. 531), or by division of the nerve of a horses's foot above the fetlock joint (op. cit., xvi. 140); and occasionally in the human subject, when the principal nerves of the limb have been divided by a gunshot wound, inflammation and mortification have taken place. The interesting facts communicated on this subject by Mr. Earle (Med. Chir. Tr., vii. 173) render it probable that these effects depend on the impairment of vitality consequent on the deficient innervation, which renders parts incapable of supporting stimuli, which in a healthy state would not be injurious. The sloughing of the nates in injuries of the spinal marrow, and of frost-bitten parts when hastily restored to life, strongly corroborate this opinion. 8. Direct irritation of the adjacent nerves has sometimes been found to excite inflammation at their extremities. (Philos. Transac. 1814, p. 583; Med. Gaz., i. 531; Med. Chir. Trans., vii. 191.) 9. The generally acknowledged fact that the condition of.the nervous system has great effect in determining the course of common inflammation. From these facts, therefore, it is clear that the nervous system exercises an important influence in inflammation, although from the illustrations which have been given, it is equally clear that this influence is rather of a negative than a positive kind. In fact the office of the nerves in inflammation appears to hold precisely the same relation to this action that it does to the other organic functions of the body. It is regulative, but not essential.] 316 HUNTER ON THE BLOOD. flamed will in every constitution be more of the healthy red when near to the source of the circulation, than when far from it. This increase of red appears to arise from two causes; the first is a dilatation of the vessels, whereby a greater quantity of blood is allowed to pass into those vessels which only admitted serum or lymph before.* The second is owing probably to new vessels being set up in the extravasated uniting coagulating lymph. This colour is gradually lost in the surrounding parts if the inflammation is of the healthy kind, but in many others it has a determined edge, as in the true erysipelatous, and in some specific diseases, as in the small-pox, where its quick termination is a sign of health. [Swelling.]—From the account I have given of the immediate effects of inflammation of the cellular membrane (in which I include the larger cavities), the volume of the part inflamed must be increased. This, when a common consequence of inflammation, is not circumscribed, but rather diffused. As the inflammation, however begins in a circumscribed part (which is at least the case with that arising from violence,) the inflammation, as I just now observed, is always greatest nearest to that point, and is gradually lost in the surrounding parts, the swelling of course being the greatest at or nearest to this point, and it is also lost in the surrounding sound parts. This takes place, more or less, according to the constitution, or the situation of the inflammation ; for if the constitution be strong and healthy, the surrounding parts will sympathize less with the point of irritation, so that inflammation and its consequences, viz., extravasation, will be less diffused. There will be less of the serum, and of course a purer coagulating lymph, so that the swelled parts will be firmer; but in some specific diseases or dissimilar parts, as a gland, it has a more determined edge, the surrounding parts not so readily taking on specific diseased action as in other cases. In this both the colour and swelling correspond very much, since they both depend on the same principle. The increase of volume is owing to the extravasation of the coagulating lymph and some serum. In proportion to the inflammation (the degree of which depends on the causes above mentioned), this effect is more or less, and therefore is greatest at the point of inflammation, becoming less and less as it extends into the surrounding parts, till it is insensibly lost in them. The extravasation of the serum along with the coagulating lymph is, probably, not a separation of itself, as in a dropsy, but a part of it being separated from the lymph in the coagulation of that fluid, is squeezed into the surrounding cellular membrane, where there is but little extravasation, and where the cells are not united by it.f Thus the circumference of such swellings is a little oedema-

* The tunica conjunctiva of the eye when inflamed is a striking instance of this; but the visible progress of inflammation I have already described in the experiment on the dog, p. 309. f [This accords with the opinion of Dr. B. C. Babington, who has attempted to prove that the fibrin and serum are always effused iu the same relative proportions THE ADHESIVE INFLAMMATION. 317 tous; but the whole of the serum, if there be a depending part, will move thither, and distend it considerably, as in the foot in consequence of an inflammation in the leg. But in most cases there is a continued extravasation of serum, long after the extravasation of the coagulating lymph is at an end; so that depending parts will continue oedematous while the inflammation is resolving, or while suppuration, or even healing is going on. The whole, swelling looks like a part of the body only a little changed, without any appearance of containing extraneous matter; and indeed it is simply formed by an extravasation of fluids without their having undergone any visible or material change, except coagulation. [Pain.']—As few uncommon operations can go on in an animal body without affecting the sensations, and as the first principle of sensation arises from some uncommon action, or alteration being made in the natural position or arrangement of the parts, we should naturally suppose that the sensation would be in some degree according to those effects, and the sensibility of the parts. One can easily form, an idea of an alteration in the structure of parts giving sensation which may even be carried to pain, but that the simple action of parts should produce sensations and even violent pain is but little known, or at least has been, I believe, but little attended to ; all these effects, I think, may justly be included under the term spasm;* at least we are led by analogy to suppose that they belong to that class. By spasm I should understand a contraction of a muscle without the leading and natural causes. Thus, the contraction of a muscle of the leg, called the cramp, gives considerable pain, often violent; as also the tetanus; and when in a less degree, as in the twinkling of the eyelid, it gives only sensation, whereas if the muscles were to act by the will no sensation would be produced. We find that those sensations are more or less acute, according to the quickness or slowness of the progress of these causes; from whence we are naturally led to assign two causes, which must always attend one another; for when both do not take place at the same time, the mind then remains'insensible to the alteration. This is its being produced in a given time, for the alteration in the position of the parts may be produced so slowly as not to keep pace with sensation, which is the case with many indolent tumours, ascites, etc.; on the other hand, this alteration in the natural position of parts may be so quick as to exceed sensation, and therefore there is a certain medium, which produces the greatest pain.

to each other. Observation, however, and the account which has been formerly given (see note, p. 314) of the gradual transformation of the secretions of an inflamed part, are opposed to this notion.—Med. Chir. Trans., xvi. 311.] ' * How far a nerve from a part, or how far the materia vita? of a part, can act so as to convey sensation I do not know; but we all know that an involuntary action of a voluntary muscle, or the spontaneous action of an involuntary muscle, will produce it. 318 HUNTER ON THE BLOOD. The actions I have been describing being pretty quick in their effects, we cannot fail to see why the pain from the inflammation must be considerable; however, the pain is not the same in all the different stages. "In the adhesive state of the inflammation it is generally but very inconsiderable, especially if it is to go no further, and is perhaps more of a heavy than an acute pain; when it happens on the skin it often begins with an itching, but as the inflammation is passing from the adhesive to the suppurative, the parts then undergo a greater change than before, and the pain grows more and more acute, till it becomes very considerable. The nerves also acquire at that time a degree of sensibility which renders them much more susceptible of impression than when they are in their natural state; thus, an inflamed part is not only painful in itself, but it communicates impressions to the mind independent of pain, which do not arise from a natural sound part. This pain increases every time the arteries are dilated, whence it would appear that the arteries do not contract by their muscular power in their systole, for if they did, we might expect a considerable pain in that action, which would be at the full of the pulse. Whether this pain arises from the distension of the artery by the force of the heart, or whether it arises from the action of distension from the force of the artery itself, is not easily determined. We know that diseased muscles give much pain in their contraction, perhaps more than they do when stretched.* That the degree of inflammation which becomes the cause of adhesions gives but little pain, is proved from the dissections of dead bodies, for we seldom or never find a body in dissection which has not adhesions in some of the larger cavities; and yet it may reasonably be supposed that many of these persons never had any acute symptoms or violent pain in those parts ; indeed we find many strong adhesions upon the opening of dead bodies, in parts which the friends of these persons never heard mentioned, during life, as the subject of a single complaint. That adhesions can be produced from very slight inflammation, is proved in ruptures in consequence of wearing a truss; for we find the slight pressure of a truss exciting such action as to thicken parts, by which means the two sides of the sac are united, though there be hardly any sensation in the part; we also see, in cases where this inflammation arises from violence, that it gives little or

* This is very evident in the bladder of urine when inflamed, for in the contraction of that viscus to expel the urine there is more pain than in the dilatation; indeed the distension is gradual; and when the urine is wholly evacuated, the irritation produced by the contraction still continues, which produces a continuance of the straining.81 a [It seems more reasonable to suppose that the pain in this instance is produced by the compression of the inflamed and highly sensible mucous membrane of the bladder against itself. The first efforts to evacuate the urine are not nearly so painful as those which follow.] THE ADHESIVE INFLAMMATION. 319 no pain. A man shall be shot through the cavity of the abdomen, and if none of the contained parts are materially hurt, the adhesive inflammation shall take place in all the internal parts contiguous to the wound made by the ball, and yet no great degree of pain shall be felt. This assertion is still proved by the little pain suffered after many bruises, where there is evident inflammation ; and in simple fractures the pain from the inflammation is very trifling, whatever it may be from the laceration of the parts. But this will be according to the degree of inflammation, what stage it is in, and what parts are inflamed, as will be fully explained hereafter. We find it a common principle in the animal machine, that every part increases in some degree according to the action required.* Thus we find muscles increase in size when much exercised ; vessels become larger in proportion to the necessity of supply, as for instance, in the gravid uterus : the external carotids in the stag, also, when his horns are growing, are much larger than at any other time; and I have observed, that in inflammation the vessels become larger, more blood, passes, and there appear to be more actions taking place; but the nerves do not seem to undergo any change. The nerves of the gravid uterus are the same as when it is in the natural state ; neither do the branches of the fifth and seventh pair of nerves in the stag become larger; and in inflammation of the nerves their blood-vessels are enlarged, and have coagu-i lating lymph thrown into their interstices, but the nerve itself is not increased, so as to bring the part to the state of a natural part, fitted for acute sensation, which shows that the motions of the nerves have nothing to do with the ceconomy of the parts; they are only the messengers of intelligence and orders. It appears that only the action of the materia vitas in the inflamed parts is increased, and this increase of action in the inflamed part is continued along the nerve which is not inflamed, to the mind, so that the impression on the sensorium is, probably, equal to the action of the inflamed materia vitas. The quantity of natural sensibility is, I believe, proportioned to the quantity of nerves, under any given circumstance ; but I apprehand the diseased sensibility does not take place at all in this proportion, but in proportion to the diseased action of the materia vitas. Thus a tendon has very little sensation when injured in a natural state; but let that tendon become inflamed, or otherwise diseased, and the sensation shall be very acute. It may not be improper to observe, that many parts of the body in a natural state give peculiar sensations when impressed; and when those parts are injured they give likewise pain peculiar to themselves; it is this latter effect which I am to consider. I may

* {This observation may be true of those parts which have naturally a fibrous texture, but certainly not of the internal viscera of the body and organs of the senses, the perfection of which is not observed to bear any proportion to their size. How far the brain is subject to this law it is for the cranioscopist to decide.] 320 HUNTER ON THE BLOOD. also observe, that the same mode of impression shall give a peculiar sensation to one part, while it shall give pain to another. Thus, what will produce sickness in the stomach, will produce pain in the colon. When the sensation of pain is in a vital part it is somewhat different from most of those pains that are common. Thus, when the pain arises from an injury done to the head, the sensation is a heavy, stupifying pain, rendering the person affected unfit to pay attention to other sensations, and is often attended with sickness, from the stomach sympathizing with it. When the pain is in the heart or lungs it is more acute, and is very much confined to the part diseased. When in the stomach and intestines, especially the upper part of them, it is a heavy, oppressive, sickly pain, bu,t>|BOjpe or less attended with sickness according to its pressure or proximity to the stomach ; for when situated in the colon it is more acute, and less attended with sickness. We cannot give a bitter illustration of this than by taking notice of the effects of a purge. If we take such a purge as will produce both sickness and griping, we can easily trace the progress of the medicine in the canal; when in the stomach it makes us sick, but we soon find the sickness becoming more faint, by which we can judge that it has proceeded to the duodenum; and then a kind of uneasiness, approaching to pain, succeeds; when this is the case we may be certain that the medicine is passing along the jejunum; it then begins to give a sickish griping pain, which I conceive belongs to the ilium; and when in the colon it is a sharp pain, soon after which a motion takes place. The liver, testicles, and uterus, are subject nearly to the same kind of pain as the stomach. A tendon, ligament, and bone give something of the same kind of pain, though not so oppressive, namely, a dull and heavy pain, often attended with some little sickness, the stomach generally sympathizing in such cases. But the skin, muscles, and the cellular membrane, in common, give an acute pain, which rather rouses than oppresses, if not too great. All of this will be further mentioned when we treat of each part. One cause of this variety of sensations, according as the parts inflamed are vital or not vital, seems to consist in the different systems of materia vitae with which those parts are supplied, having, probably, nerves peculiarly constructed for this purpose ; for all the parts which are supplied with branches from the par vagum and intercostals affect the patient with lowness of spirits from the very first attack of the inflammation : the actions of those parts are involuntary, and therefore are more immediately connected with the living principle, and consequently that principle is affected whenever anything affects these nerves. The other system of the materia vitae, when affected by this inflammation, rather rouses at first the constitution, which shows signs of strength, unless the parts have rather weak powers of recovery, such as tendon, bone, etc., or are far from the heart, in which cases the signs of weakness sooner or later appear: hence it would seem that this difference THE ADHESIVE INFLAMMATION. 321 in the constitution, arising from the difference in parts and their situation, arises from the constitution having a disease which it cannot so easily manage, as it can in those parts which are not vital, and in parts that are near to the heart; which circumstances alone become a cause of irritation in the constitution.

§ 3. The Heat of Parts in Inflammation.

When I was treating of the blood I observed that the heat of the animal was commonly considered as connected with that fluid; but as I had not made up my mind about the cause of the heat of animals, not being satisfied with the opinions hitherto given, I did not endeavour to offer any account of that property; but I shall now consider this power when the animal is under disease, where it would appear often to be diminished, and often increased, and of course the animal often becomes colder and hotter than its natural temperature. There is an endeavour to bring the heat of a living body to the temperature of the surrounding medium, but in the more perfect animals this is prevented by the powers in the animal to support its own temperature, more especially in and near the vital parts ;* therefore, in making experiments, to ascertain any variation, it is not necessary to ascertain at the same time the temperature of the atmosphere. Heat, I imagine, is a sign of strength and power of constitution, although it may often arise from an increased action either of weak constitutions or of weakened parts. Heat is a positive action, while cold is the reverse, therefore producing weakness, and often arising from a diminished action of strong parts.f

* [This uniformity of temperature is not, however, by any means so universal, even in health and in the higher animals, as has often been supposed. De la Roche and Berger found that warm-blooded mammalia, exposed for long periods to a high temperature, experienced an elevation equal to 10°, and sometimes 13°. Dr. Edwards and M. Despretz found a difference of 6° in birds in the winter and summer months, being in the former 105° and in the latter 1110. Dr. Davy found that the standard heat of the Cingalese varied from 1° to 2° above the average in more temperate climates. Dr. Fordyce and his friends experienced an elevation of 2° or 3° in their experiments on heated air, and De la Roche an elevation of 5° after remaining seventeen minutes in a vapour bath at 120°. The singular power which the body possesses of accommodating itself to the extremes of external circumstances, is well exemplified by a fact recorded by Capt. Lyon in Capt. Parry's second voyage to the arctic regions, where the temperature of eleven out of sixteen foxes, killed in Winter Isle (lat. 66° 11', temp. —3° to —32°) varied from 100° to 106$° at their vital parts; as well as by the counter-fact that the temperature of persons exposed to very high degrees of natural heat, as at Sierra Leone, (100° to 103°), Senegal (108£° to 117^°), Oronoco (110° to 115°), &c, does not in general vary more than a few degrees from the standard heat. How this is accomplished has been fully shown by M. de la Roche, Journal de Physiologie, lxiii., lxxi., and lxvii.] f [See note, p. 270.] 28 322 HUNTER ON THE BLOOD. It has not yet been considered whether an animal has the power of producing heat equally in every part of the body, although, from what is generally advanced on this subject, we are led to suppose that every part has this power, or whether it is carried from some one source of heat by the blood to every part; this may probably not be easily determined ; but I am apt to suspect there is a principal source of heat, although it may not be in the blood itself, the blood being only affected by having its source near the source of heat. That this principle resides in the stomach is probable, or at least I am certain that affections of the stomach will produce either heat or cold. There are affections of the stomach which produce the sensation of heat in it, and the air that arises in eructations feels hot to the mouth of the person ; but whether these sensations arise from actual heat, or from sensation only, I have not been able to determine. Stimulating substances applied to the stomach will produce a glow. Affections of the mind produce the same effect, which last circumstance might seem to contradict the idea of its arising from the stomach ; but I suspect that the stomach sympathizes with those actions of the brain which form the mind, and then produces heat, which will be better illustrated in treating of cold. I suspect that the cold bath produces heat in the same way, from the sympathizing intercourse between the skin and the stomach. That diseases augment or lessen this power in the animal is evident; for in many diseases the animal becomes much hotter,and in many others much colder than is usual to it. This fact was first discovered by simple sensation alone, both to the patients themselves and the practitioner, before the absolute measurement of the degrees of heat by instruments was known; but it was impossible that such knowledge of it could be accurate, for we find by experiment that the measurement of degrees of heat by sensation is very vague. This happens because the degree of heat in ourselves (which in such experiments is the instrument) is not of one standard, but must vary pretty much before we are made sensible of the difference, and therefore there can be only a relative knowledge respecting our own heat at the time. But now our measurement is more determined, and can be brought even nearer to the truth than is absolutely necessary to be known in disease. The increase and decrease of the heat of an animal body may be divided into constitutional and local. The constitutional arises from a constitutional affection, and may arise primarily in the constitution itself; or it probably may arise secondarily, as from a local disease with which the constitution sympathizes; but of this I am not yet certain, for from several experiments made to ascertain this point, it seemed to appear that local inflammation had little power of increasing the heat of the body beyond the natural standard, although the body was under the influence of the inflammation by sympathy, called the symptomatic fever; but if the heat of the body is below the natural heat, or that heat where actions, whether THE ADHESIVE INFLAMMATION. 323 natural or diseased, are called forth, then the heat of the body is raised to its natural standard.* As it is the principle of increase of local heat in inflammation I am now to consider, it should be first ascertained how far such a principle exists in a part, and what that principle may be; the constitutional principle being in some measure not to the present purpose, although it may throw some light on the difference between the powers of the constitutional and those of the local principle. It is said that disease, as fever, has been known to raise the heat of the body to twelve degrees above the natural heat; and if so, then there is in such cases either an increased power or an increased exertion of that power; and to know whether this arises only from a constitutional affection at large, or whether it can take place in parts when the constitution is affected by those parts, is worthy of inquiry. The principal instance of supposed increased local heat is in inflammation, and we find that external parts inflamed do actually become hotter; but let us see how far the increase goes. From all the observations and experiments I have made, I do not find that a local inflammation can increase the local heat above the natural heat of the animal; and when in parts whose natural heat is inferior to that which is at the source of the circulation, it does not rise so high : those animals, too, which appear to have no power, either of increase or decrease in health, naturally appear to be equally deficient in disease, as will be seen in the experiments. I suspect that the blood has an ultimate standard heat in itself when in health, and that nothing can increase that heat but some universal or constitutional affection; and probably the sympathetic fever is such as has no power in this way, and that the whole power of local inflammation is only to increase it a little in the part, but that it cannot bring it above the standard heat at the source, nor even up to it in parts that naturally or commonly do not come up to it, as just above mentioned. As inflammation is the principal instance capable of producing local increased heat, I have taken the opportnuity of examining inflammations, both when spontaneous and in consequence of operations. I have also made several experiments for that purpose, which are similar to operations, and cannot say that I ever saw, from all these experiments and observations, a case where the heat was really so much increased as it appeared to be to the sensations.

Experiments on Internal Surfaces.

Experiment 1. A man had the operation for the radical cure of the hydrocele performed at St. George's Hospital. When I opened the tunica vaginalis I immediately introduced the ball of the thermometer into it, and close by the side of the testicle. The mercury * Vide Animal CEconomy, Paper 14. 324 HUNTER ON THE BLOOD. rose exactly to 92°. The cavity was filled with lint, dipped in salve, that it might be taken out at will; the next day, when inflammation was come on, the dressings were taken out, and the ball of the thermometer introduced as before, when it arose to 98£° exactly. Here was an increase of heat of Gi°, but even this was not equal to that of the blood, probably, at the source of the circulation in the same man. This experiment I have repeated more than once, and with nearly the same event. As the human subject cannot always furnish us with opportunities of ascertaining the fact, and it is often impossible to make experiments when proper cases occur, I was led to make such experiments on animals as appeared to me proper for determining the fact; but in none of them could I ever increase the inflammatory heat so as to make it equal to the natural heat of the blood at its source. Experiment II. I made an incision into the thorax of a dog; the wound was made about the centre of the right side, and the thermometer pushed down, so as to come in contact, or nearly so, with the diaphragm. Thedegree of heat was 101°; a large dossil of lint was put into the wound to prevent its healing by the first intention, and covered over by a sticking-plaster. The dog was affected with a shivering. The day following the lint was extracted, and the thermometer again introduced ; thedegree of heat appeared exactly the same, viz., 101°. This dog recovered. Experiment III. An oblique incision was made about two inches deep in the gluteal muscles of an ass, and into this wound was introduced a tin canula about an inch and half long, so that half an inch of the bottom of the wound projected beyond the canula ; into this canula was introduced a wooden plug, which projected half an inch beyond the canula, so as to fill up the bottom of the wound, and which kept that part of the wound from uniting. The whole was fastened into the wound by threads attached to the skin. Immediately upon making the wound the ball of the thermometer was introduced into it to the bottom, and the mercury rose to 100° exactly, as it did also at the same time in the vagina. On the next morning the wooden plug was taken out, and the ball of the thermometer (being previously warmed to 99°), was introduced down to the bottom of the wound, which projected beyond the canula, and the mercury rose to 100.° The wooden plug was returned and secured as before. In the evening the same experiment was repeated, and the mercury rose to 100°. Friday morning it rose only to 99°. Friday evening it rose to near 101 $°. Saturday morning 99°, and the evening 100°. A similar experiment to this was made on a dog, and the heat was 101°. The day following the heat was the same, as also on the third day, when suppuration was taking place. Experiment IV. Although in the experiment upon the dog, by making an opening into the thorax so as to excite an inflammation there, and to affect his constitution, the heat of the part was not in- THE ADHESIVE INFLAMMATION. 325

creased ; yet in order to be more clear with regard to the result of such an experiment, a wound was made into the abdomen of an ass, and a solution of common salt and water thrown in (about a handful to a pint of water), to excite a universal inflammation in the cavity of the abdomen. This produced great pain and uneasiness, so as to make the animal lie down and roll, becoming as restless as horses when griped. The next morning, Friday, the thermometer was introduced into the vagina, and the mercury stood at 99£°, nearly the same heat as before the experiment; in the evening, 10U°. Saturday morning, 100£°; evening, 100£°. The vagina, therefore, was not rendered hotter by an inflammation which produced what we may call the sympathetic fever. The animal was now killed, and on examining the abdomen, the side where the wound was made appeared much inflamed, as well as the intestine opposite to this part. All of them adhered together, and the intestines surrounding this part of the adhesions had their peritoneal coat become extremely vascular, and matter was formed in the abdomen. But that the heat of a part can be increased above the common standard of a healthy person is certain, when it is such a part as is naturally of the standard heat, as, for instance, the abdomen. For in Lord Hertford's servant, who was tapped eight times, and seven of them in thirteen weeks, the seventh time I held the ball of a thermometer in the stream, as it flowed from the canula of the trocar, and it raised the mercury to 101° exactly, through the whole time. Twelve days after I tapped him the eighth time ; the water was pretty clear; when I held the thermometer in the stream it rose to 104°. Now as the heat of the abdomen was 104°, we must, I think, suppose that the general heat of the man would also be 104°.

Experiments on Secreting Surfaces.

Experiment I. I took the degree of heat of a dog's rectum, by introducing the thermometer about three inches; and when it was ascertained, four grains of corrosive sublimate were dissolved in two ounces of water, and the solution thrown up the rectum. The day following the thermometer was again introduced, and then I found the heat somewhat increased, hut not quite a degree. As far as one might judge from external appearances, the rectum was very much inflamed, as there was a considerable external swelling, forming a thick elevated ring round the anus. Experiment II. I introduced into the rectum of an ass the ther mometer, and the mercury rose to 98$° exactly ; this was repeated several times with the same result. I then threw up the rectum an injection of flour of mustard and ginger, mixed in about a pint of water. About twelve hours after 1 introduced the thermometer, and it rose to 99|°. The injection was repeated several times, but the heat did not increase. 28* 320 HUiNTER ON THE BLOOD. Experiment III. To irritate the rectum still more, I threw up a solution of corrosive sublimate, and about twelve hours after I introduced the thermometer, and found no increase of heat. Twenty hours after I introduced the thermometer, but the heat was the same. Sixty hours after the injection, the thermometer being introduced, the mercury rose to 100° exactly. This injection had irritated so much as to "give a very severe tenesmus and even blood passed. Experiment IV. The natural heat of the vagina of a young ass was 100°. A solution of corrosive sublimate, as much as would dissolve in a tea-cupful of water, viz., about ten grains, was injected into the vagina. In about two hours after the mercury fell to 99°. Thursday morning, 99°; evening, 100°. Friday morning, 99°; evening, near to 101°. Saturday morning, 99; evening, 100°. This experiment was repeated several times upon the same ass with the same result. In these experiments it can hardly be said that the heat was increased. That the inflammation had been raised to a very considerable degree was plain, for it produced a discharge of matter which was often bloody, and upon killing the ass for another experiment, the following appearances were found in the uterus. The horns of the uterus were filled with serum, and the inflammation had run so high by the stimulating injections which were used for the experiments on the vagina, that the coagulating lymph had been thrown out so as almost to obliterate the vagina, uterus, etc., by those adhesions which are the ultimate effects of inflammation on secreting canals, while suppuration is the ultimate effect of inflammation on internal surfaces: there were no signs of inflammation on the external surface of the uterus, which is covered by the peritonaeum. It may just be remarked, that in most of those experiments the heat in the morning was a degree less than in the evening ; and I may also remark, that this is commonly the case in the natural heat of the animal. I wished to know whether such animals as have little or no power of varying their natural heat had a power of increasing their heat in consequence of injuries, for which purpose I opened into circumscribed cavities in frogs, toads, and snails, and at different periods, after the opening was made, the thermometer was introduced. As the heat of those animals is principally from the atmosphere, the external heat is to be connected with the experiments.

Experiments on cold-blooded Animals.

Nov. 27, 1788. A healthy toad and frog, after having the heat in the stomach ascertained, had openings made through the skin of the belly, large enough to admit a thermometer, and the orifice was kept open by a piece of sponge. THE ADHESIVE INFLAMMATION. 327 Atmosphere, 36°; stomach of both, 40°; underskinofthebelly,40°. Atm. Frog. Toad. Stom.

Under the skin. Half an hour after the opening . . 35° 40° 40° 40° Hour and a half......35 39 39 — Two hours and a half.....— 39 39 — The abdomen was now opened, and a piece of sponge kept in the orifice. Atm. Frog. Toad. Stom.

Part of the left oviduct protruded, of the natural colour and appearance. Atm. Frog. Toad. Stom. Nine hours after......38° 38° 38° 38° Twenty-one hours and a half . • 35 35 35 35

The protruded oviduct was more vascular, and of a uniformly red appearance; it was returned into the belly and retained there. Atm. Frog. Toad. Stom. Twenty-four hours.....32° 32° 32° 32° Forty-six hours......34 34 34 34 The toad died, and the frog was become very weak and languid: part of the oviduct protruded, and had the small vessels loaded with blood. It lived one hundred and eighteen hours ; that is, seventytwo longer than the toad, during which period its heat corresponded with the atmosphere. Upon examining the abdomen after death, there were no adhesions nor any appearances from inflammation, except on the protruded oviduct. Some healthy shell-snails had openings made into the lungs, and their heat ascertained at the following times : Atm. Snail. The heat at the time ...... 34° 38° One hour and a half......32 32 Six hours and a half......32 35 Ten hours.........31 36 Twenty-four hours......30 30

To ascertain the standard heat of a snail: Atm. Snail. A fresh lively snail had its heat in the lungs . 30° 36° Another.............28 35 Another . . . •.........30 37 328 HUNTER ON THE BLOOD. Experiments to ascertain the heat of worms, leeches, and snails, when compared with the atmosphere, and the changes produced in their heat by inflammation.

Leeche's \tWent;KOUr hours after being/ 55 Slugs . J wounded.......I 55 They were all very weak and dying.* * [The production and phenomena of animal temperature have been referred to more specifically elsewhere. (Principles of Surgery, p. 70, and Animal (Economy, Paper 14.) It only, therefore, becomes necessary to mention here the intimate association which exists in all instances between the calorific and respiratory functions, so that throughout the animal series the degree of temperature evolved is in accurate correspondence with the elaborateness of the respiratory apparatus and the perfection with which the chemical changes on the blood are accomplished, leaving no doubt in the mind as to the relation in which these functions stand to each other. If we adopt the view formerly suggested (see note, p. 96), of the absorption of oxygen into the blood, and its gradual conversion into carbonic acid in the course of the circulation, especially in the peripheral capillaries, it will not be difficult to explain the variations which sometimes occur in the local temperature, depending, as they would seem to do, on the varying afflux of blood to particular parts, or to the varying activity of the nutritive functions. That these circumstances, however, are greatly under the dominion of the nervous system, the observations and experiments of Brodie, Home, Earle, Wilson Philip, Mayo, Le Gallois, and others have incontestably proved (Phil. Trans., ci. 36, cii. 380, cxv. 7; Med. Chir. Trans., vii. 173; Ann. de Chimie, iv. (1817); and Wilson Philip, On the Vital Functions, 2d edit., p. 168), although in no other manner dependent than all the other functions of organic life. The observation of Hunter, that the generation of heat cannot essentially " depend upon the nervous system, for it is found in animals that they have no brain or nerves," is still further corroborated by the fact that the same phenomenon is observed in vegetables, in which there is still less pretence or proof of a nervous system. Thus, during the germination of seeds, the temperature is elevated at least ten degrees. Hubert found that the thermometer was raised to 108° Fahrenheit when surrounded by the spadices of the Arum cordifoliuni during the process of fecundation, the temperature of the atmosphere being 70°; and Sennebier, that it was raised from 70° to 143° under the same circumstances. (Ellis on Respiration, p. 204.) The phenomena which appear most difficult to account for are the occasional exaltation of temperature in parts, beyond the standard heat of the body; especially where, as iu THE ADHESIVE INFLAMMATION. 329 § 4. Of the Production of Cold in Inflammation.

The production of cold is certainly an operation which the more perfect animals are endowed with; and this power would appear to be both constitutional and local, similar to the power of producing heat. As the word inflammation implies heat, and has been used to express that action of the vessels where heat is commonly an effect, it may seem strange that we should treat of cold in the action of inflammation. But probably we have no action in the body that sjnot attended with an occasional production of cold. How far th s takes place in parts I do not know ; but that it takes place constitutionally, from almost every affection, is evident, whether it be inflammatory fever or local inflammation. As an animal has no standard of cold but at the source, which is also the standard of heat, it is perhaps impossible to ascertain with certainty the degree of cold produced either by disease or from the surrounding cold ; but perhaps, by comparing the part suspected of being colder, than is natural, from disease, with a similar part under the same external influence of heat and cold, as, for instance, one limb with the other, or one hand with the other, a pretty fair inference may be made; and we often find that diseased parts shall become extremely cold, while from other circumstances than disease they should not be so. I suspect that coldness in disease arises either from weakness, or a feel or consciousness of weakness, in the whole constitution or a part, joined with a peculiar mode of action at the time. Thus we have many constitutional diseases beginning with absolute coldness, which seems afterwards to terminate in a sensitive coldness only, as the cold fit of an ague ; for I apprehend that the sickness which generally precedes such complaints produces universal cold, and once having produced the action of the body arising from absolute cold, the action goes on for some time, although the cause no longer exists, which continues the sensation; and although the absolute coldness is gone, yet the action of the parts, which is a continuation of and therefore similar to the action of the absolute cold, is capable of destroying itself by producing the hot fit, if there be power or disposition.

fractures and injuries of the spine, the cause would appear not only inadequate to the effect, but to have a directly contrary tendency. In inflammation, on the contrary, the reparative and nutritive functions are in an undue state of activity, and therefore it is reasonable to suppose that the peculiar changes consequent on the circulation of the blood are carried on with greater vigour. The author, it may be observed, accounts for the production of animal heat by referring to the vital principle, which, after all, throws no light upon the subject, nor gives any account of the immediate agency by which this is produced. That the stomach may often indirectly become the cause of the production of partial cold, is readily explained, when we consider the influence which it is admitted that the nervous system exercises over the function of calorification, and the power which the stomach has of affecting the former.] 330 HUNTER ON THE BLOOD. That weakness, or a feel of weakness, produces cold is evident, and that universal or constitutional cold arises from the stomach is also evident; for whenever we are made sick an universal coldness takes place; and this is best proved by producing sickness on animals that we can kill, or that die while they are under these affections of the stomach. The experiments I made to ascertain this were not conducted with great accuracy, as I trusted in them entirely to my own sensations or feelings. Experiment I. I threw three grains of tartar emetic into the veins of a healthy bitch, the quantity of water near an ounce. In about twenty minutes she had a stool and voided some single tapeworms. Some of the stools were extremely thin, and made up principally of bile. Some time after she had two more stools, which were thin and bilious. She continued pretty easy for about three hours, but became a little convulsed, which increased, and at last she became senseless, with little twitchings; hardly breathing, except with the diaphragm, and having a low, slow pulse. She was very cold to our feel, when applying our hand on the skin of the body. In about ten or twelve hours after the injection she died. Experiment II. I repeated the above experiment on another bitch, adding a full grain more to the medicine. She vomited in less than a minute after it was thrown in, and strained excessively hard, throwing up a great deal of froth, which was only the mucus of the stomach mixed up with the air in the act of retching. In less than three minutes she had a stool, which was pretty loose and partly of the natural appearance. She continued retching and purging for above an hour, and was extremely uneasy ; at last she got into a dark corner and lay there, frothing at the mouth, was taken with convulsive twitchings like the former, and died in about five hours after the injection. I opened her body immediately after death, and found the intestines, liver, and heart not so warm as we usually find them. I have known people who had affections of the stomach and bowels say that they had plainly the feeling of cold in their bellies. I knew a gentleman who told me that often when he threw the wind off his stomach it felt cold to his mouth and even to his hands, which was by much the best guide respecting sensation. A lady, near seventy years of age, has a violent cough, which often makes her puke, and what comes off her stomach feels like ice to the mouth. Affections of the mind also produce constitutional coldness; but they are such affections as the stomach sympathizes with, producing sickness, shuddering, &c. A disagreeable idea or sight will sometimes give a quick sensation of sickness, and the skin shall sympathize with the stomach. It shall appear to begin, as it were, in the mouth or throat, as if something there had a tendency to come up; the muscles of the neck shall become convulsed, and the head shall be violently shaken; from thence a disagreeable feeling shall spread over the whole body, passing directly down the back to THE ADHESIVE INFLAMMATION. 331

the feet, commonly expressed by saying, " one's flesh creeps;" and hence the words shudder and horror express mental as well as bodily affections. Another action shall be joined with the cold, viz., the action of sweating, so that a cold sweat shall take place over the whole body. This cold shall be partial, for under many diseases a partial cold sweat will sometimes come on, while other parts remain tolerably temperate.

§ 5. Of the time the Adhesive Inflammation commences after its cause ; and in what cases and parts it is imperfect in its consequences.

It will be often impossible to determine the distance of time between the impression which becomes the cause of inflammation and the action itself; which will depend upon two circumstances, viz., the nature of the exciting cause, and the susceptibility for such action in the parts. In the exposure of internal surfaces, inflammation is perhaps sooner brought on than in most others; for the incitement is immediate, and there is no remission in the cause itself. In specific diseases the time is perhaps more regular, each having a determined interval between the application of the exciting cause and the appearance of the disease, although even in some of these there is a vast difference in the time after contamination; but in those arising spontaneously it must be uncertain. Yet in some cases it can be pretty well ascertained, supposing sensation the first effect of the inflammatory impression; and in such instances we often find it very rapid. They shall be attacked with a violent pain in the part, so much so as hardly to be able to bear it, which shall be immediately succeeded with a violent inflammation. A lady was walking in her garden, and at once was attacked with a violent pain in the middle of the fore part of the thigh, which made her immediately lame. Soon after, the skin appeared discoloured, which spread nearly over one-half of the thigh : this part became thick and swelled, which appeared to go as deep as the bone. It afterwards suppurated ; all in a few days. This appeared to be a well-marked case. The commencement of inflammation after accidents is more easily ascertained, for we must date it from the accident, and we find it is not immediate; for after a wound has been received, inflammation does not begin for twelve, eighteen, or twenty-four hours. It sometimes happens, however, that the adhesive state cannot set bounds to itself, and therefore cannot set bounds to the suppurative. This may be owing to two causes; the one is the violence of the inflammation, and quickness of the attack of the suppurative spreading before parts have had a sufficient union, and even perhaps joined with a species of suppuration from the very first, so that union is prevented. Secondly, the inflammation may, I sus- 332 HUNTER ON THE BLOOD. pect, be of the erysipelatous kind, especially when there is a tendency, from the beginning, to mortification. This mixing of the suppurative with the adhesive, or the hurrying on of the suppurative, or this mixture of the erysipelatous with the others, I have frequently seen in the abdomen of women who have been attacked with the peritoneal inflammation after childbirth, and which from these circumstances became the cause of their death. In such cases we find matter mixed with coagulating lymph, as if formed with it; for without having been formed with it, it could not have mixed with it after coagulation. We find also coagulating lymph mixed with the matter, as it were, separated from the inflamed surface by the formation of the matter; and in those cases where there is a tendency to mortification from the beginning, as in strangulated ruptures, we often find the adhesive and suppurative inflammation going hand in hand. All of these causes and effects account for the violence of the symptoms, the quickness of the progress of the disease, and its fatal consequences, beyond such inflammations as have only the true adhesive progress, or where it takes place perfectly prior to suppuration. It seems to appear, from observation, that some surfaces of the body do not so readily unite by the coagulating lymph as others, and therefore on such surfaces there is commonly a much larger quantity of this matter thrown out than probably would have been if union had readily taken place; for we may suppose that where once union has taken place extravasation is at an end. Thus we see in (what we may suppose) inflammation of the heart, that the coagulating lymph is thrown out on the exterior surface in vast quantities, while at the same time the heart shall not adhere to the pericardium. This is not only seen in the human subject, but in other animals; in an ox the heart was furred all over, and in some places the coagulating lymph was near an inch in thickness. The external surface of such hearts has an uncommon appearance: the outer surface of the coagulable lymph is extremely irregular, appearing very much like the external surface of a sponge, while the base or attachment to the heart is very solid and firm. However, in many instances we find the pericardium adhering to the heart, and generally in pretty close contact, which would make us suppose that the extent of motion of those two parts on one another is not great. These adhesions affect the pulse much, which is a good reason why nature avoids them as much as possible. On the other hand, it seems deducible from observation that neither the pia mater nor dura mater is apt to throw out much coagulating lymph, for here it would produce compression ; and therefore we seldom find adhesions between them, in consequence of such accidents as produce suppuration between these two membranes: we seldom if ■*ever find the surrounding parts adhering so as to confine the matter to the suppurating surface. Inflammation of the skin, or such as approaches to the skin, produces in general a separation of the cuticle, often of the hair or the THE ADHESIVE INFLAMMATION. 333 nails. These effects arise sooner or later, according to the nature and degree of the inflammation, but more particularly according to its nature; they take place the least and latest in the true adhesive inflammation, which is always attended with the greatest strength. In such cases the separation does not happen till the inflammation has subsided; and, as a proof of this, in the gout it is least and latest of all, for this is always a healthy inflammation, otherwise it would not take place; but in weak habits, at the early part of the disease, there are often vesications, which are filled with serum, sometimes with coagulating lymph, &c, both of which are sometimes tinged with red blood. When the inflammation is of a weak kind, tending to mortification, the cuticle commonly separates early during the time of inflammation, almost beginning with it, and of course the vesications will be filled with serum, and often with the red globules. We may observe in wounds of the skin which are not allowed to heal by the first intention, that a separation of the cuticle will take place at the edges of the wound, and this will extend according to the nature of the inflammation, which is according to the nature of the constitution. This will be attended with other concomitant appearances, such as flabby edges and thin matter. I conceive in the weak habit it depends on an action of the inflammation itself, but in the strong it depends on a state in which the parts are left to separate the cuticle. This separation arises, I apprehend, from a degree of weakness approaching to a kind of death in the connexion between the cuticle and cutis, from life being in this part naturally very weak. In the beginning of mortification it is produced; in the oedematous and erysipelatous inflammations it is greatest, and in putrefaction of dead bodies it is the first operation. I suspect, too, that a blistering plaster, hot water, &c, only kill the uniting parts, by which means an irritation is produced in the cutis, and the extravasation is according to that irritation. The connexion of the cuticle is more or less destroyed in every inflammation of the skin, for we seldom see an inflammation attack the skin but the cuticle comes off sooner or later. We generally observe it pealing off in flakes, after inflammation has subsided, and it begins nearest the point of inflammation.*

§ 6. Of the Uniting Medium in Inflammations. Every new substance that is formed is either for a salutary purpose, or it is diseased. The first consists either of adhesions or

* It may be observed, that when an inflammation attacks the finger-enfls or toes, so as to produce suppuration either in the substance of these parts, although not larger than a pimple, or only on the surface ofthe cutis, an extensive separation of the cuticle takes place, not entirely from the inflammation, but assisted by it. This is owing, principally, to the cuticle in such places not giving way, being there strong, so that a seeming abscess almostoccupies the whole finger, &c. This should be opened early to prevent this separation as much as possible, or to prevent the separation from extending too far. 29 334 HUNTER ON THE BLOOD. granulations, whether with the first or second intention; and these may be considered as a revival of the natural principles, and powers of growth, whereas diseased substances are, as it were, monsters. In the adhesive inflammation, the vessels being enlarged, as above described, similar to what they are in the young subject, begin to separate from the mass some portion of the coagulating lymph, with some serum, and also red globules, and throw it out on the internal surface, probably through the exhaling vessels, or perhaps open new ones, and cover the sides of those cells, which easily unite with the opposite, with which they are in contact, forming the first progress of adhesions. That this is really the case, and that this effect has taken place in consequence of inflammation, is evident from the following observations. In all large cavities where we can make our observations with certainty, when in the state of inflammation, we find diffused over the sides, or through the cavity, a substance exactly similar to the coagulating lymph when separated from the serum and red blood, after common bleeding. That the blood when thrown out of the circulation from an inflammatory state of the vessels, as well as the blood itself, unites parts together, is probably best seen in the inflammation of the larger cavities above mentioned. The following I shall give as an example, which I have often observed on the peritonaeum of those who have died in consequence of inflammation of this membrane. The intestines are more or less united to one another, and, according to the stage of the inflammation, this union is stronger or weaker; in some it is so strong as to require some force to pull them asunder;* the smooth peritonasal coat is, as it were, lost, having become cellular, like cellular membrane. When the vessels of this part are injected, we shall find that in those parts where a separation has been made by laceration, previous to the injecting, the injection will appear on that surface like small spots or drops, which shows that the vessels had at least passed to the very surface of the intestines. In parts where the union was preserved I have observed the three following facts. On separating the united parts I have observed in some places the vessels come to the surface of the intestines, and then terminate all at once. In other places I could observe the vessels passing from the intestine into the extravasated substance, and there ramifying, so that the vessels was plainly continued from the old into the new. In a vast number of instances I have observed, that in the substance of the extravasation there were a great number of spots of red blood in it, so that it looked mottled. The same appearance was very observable on the surface of separation; between the old substance and the new, a good deal like petechial spots. How this red blood got here is the thing to be considered, especially

* Adhesions in consequence of inflammation become very soon strong, and are very soon elongated ; probably as soon as they become organized they adapt themselves to their situation or the necessity. Thus the dog which had his belly opened to wound some lacteals, when killed on the ninth day, had his intestines connected by adhesion in several places, and those very firm and long. THE ADHESIVE INFLAMMATION. 335 as a good deal was within the substance of the coagulum. Was it extravasated along with the coagulated lymph ? In this case I should have rather supposed it would have been more diffused, and if not diffused, more attached to the intestine, and not in the centre of the coagulum; if it had been extravasation, one would have expected extravasation of injection, but we had none in any of these places ; I have therefore suspected that parts have the pov.sr of making vessels and red blood independent of circulation. This appears to be evidently the case with the chick in the egg.* I have observed, when I was treating of the blood, that it was capable of becoming vascular, when deposited either by accident, or for particular purposes ; and I had reason to believe that a coagulum or coagulating lymph had a power of becoming vascular in itself when it could be supplied with blood, and mentioned the coagulum in a large artery as an instance. Likewise, when 1 was treating of union by the first intention, I explained the intercourse established by the uniting medium becoming vascular, and those vessels uniting across by a process called inosculation. The same reasoning is applicable to the union by means of the adhesive inflammation : for it is the blood in all cases that is to become vascular ;f but this takes place sooner or later, according to the apparent necessity. In some it becomes vascular immediately, in others very late, and indeed in some hardly ever, according to the degree of utility to arise from that change. Where it becomes vascular soonest, there the vessels are found also in greatest numbers, the two effects depending on the same principle. Extravasation, whether of blood or only of lymph, becomes vascular almost immediately when thrown out into the cavity of the human uterus in the state of pregnancy. Here is an operation necessary to go on, which is more than the simple support of the extravasation itself; but when the extravasation is thrown out by accident, or for the purpose of producing adhesions, the immediate intent is answered without the vessels, and vascularity only becomes necessary afterwards; therefore vascularity in such cases is the second consideration, not the immediate one. But in the case of impregnation it must be immediate, for the simple extravasation would not answer the intention. This shows that this extravasation is very different from that of the menses. The new vessels which are formed in the newly extravasated and uniting substance become of use, both during the state of adhesion and suppuration. In the first they serve to give powers of action to this new substance, which assists in preventing suppuration. In the second, where this cannot be done, they assist in forming a vascular basis for the granulations. When we cut into inflamed parts after death we find them firm and solid,.resembling the section of a lemon, or some oedematous

* [See p. 71, and note, and also the note to the explanation of Plate I.] t [See note, p. 258.] 336 HUNTER ON THE BLOOD. tumour, where we know extravasation has taken place. This appearance arises from the cells in the cellular membrane, and other interstices of parts, being loaded with extravasated coagulating lymph; from this circumstance they are cemented together, and become impervious to air, not similar in these respects to common cellular membrane or natural parts. In many places where this extravasation has been in considerable quantities, it is formed in time into cellular membrane. I have observed that this mode of separation of the coagulating lymph is not peculiar to inflammation ; it is separated in many diseases. It is thrown out to form tumours, etc., where inflammation does not seem to be a leading cause ;* and we often find the adhesive stages, as it were, degenerate into, or terminate in the formation of a cyst, to contain the body that was the cause of the inflammation. Thus, a sac is formed for bullets, pieces of glass, etc. It is unnecessary to instance every possible situation where adhesions could be produced; they can take place wherever there are two internal surfaces in contact, or that can be brought into contact. I cannot give a better instance of its utility in the animal oeconomy than in the following experiment; I wished to know in wounds which penetrated into the chest (many of which I have seen in the army), where suppuration had come on the whole cavity of the chest, as well as on the surface of the lungs, and where the lungs collapsed, how parts were reinstated, or in what form they healed ; whether the lungs, etc., lost their suppurating disposition, and dilated, so as to fill the chest again. To ascertain this as far as one well could, I made the following experiment on a dog. October 1779 I made an opening between the ribs into the chest of a dog, and touched the edges of the wound all round with caustic, to prevent it from healing by the first intention, and then allowed the dog to do as he pleased. The air at first passed in and out of his chest by the wound. He ate, etc., for some days, but his appetite gradually began to fall off. He breathed with difficulty, which increased ; he lay principally on that side which we find people do who have the lungs diseased on one side only or principally; and he died on the eleventh day after the opening. On opening the body T found the collapsed lungs passing directly across the chest, and attached to the inside of the wound all round, so that they excluded the cavity of the chest from all external communication. This circumstance, of the lungs falling across the chest, was owing to his having lain principally on that side, which I conceived to have been only accidental. The cavity of the chest all round was filled with air. That part of the external surface of the lungs which did not adhere, that is to say, the part opposite the upper surface of the diaphragm, and that part of the pleura which covered the ribs, were entirely free from inflammation or suppuration : this cavity, from these adhesions, being rendered a perfect * [See note, Principles of Surgery, p. 150.] THE ADHESIVE INFLAMMATION. 337 cavity, shows that air, simply, has no power to excite inflammation when the cavity is otherwise perfect, which the adhesions had effected; this shows also that adhesions of two surfaces round the exposed part exclude every part from the necessity of inflammation, as was explained when treating of inflammation. From the connection between the living powers of the solids and the fluids, we can hardly suppose that such an uncommon action could take place in the vascular system without producing its effects upon the fluids; and therefore, from reasoning, we might suppose that the coagulating lymph undergoes some changes in its passage through the inflamed vessels, which obliges it to coagulate more immediately, or much sooner than it otherwise would.* For in those cases of inflamed arms, after bleeding, and in inflammations in consequence of other causes, we find that the cavities of the veins are in many places furred over, and in others [the sides] united by means of the coagulating lymph. Now if this coagulating lymph is'similar in its production to that which we have been describing, it must have been thrown out from the vasa vasorum, these vessels having separated it and poured itintothe cavity of the veins, and it must there have coagulated immediately; in this separation, therefore, from the blood, it must have undergone some change, arising from the actions of the vessels; for if this lymph was no more than the coagulating lymph with its common properties, or the properties common to that which is circulating in the same vein which receives it, it would in such cases only continue to throw in more coagulating lymph, in addition to what was circulating, and therefore, probably, it would be carried along with the blood to the heart, as a part of the common mass. From this we should infer that this coagulating matter is not simply the coagulating lymph, such as it is when circulating, but somewhat different, from having undergone a change in its passage through the inflamed vessels, partaking of the disposition of those solids which are inflamed through which it passed. This process cannot therefore be supposed to be merely extravasation; for I conceive that an oedema would be a consequence of simple extravasation. But this may be taken up in another point of view, and upon the same principle. The inflamed vessels may give a disposition to the blood, as it is moving slowly along, to coagulate on its surface; and this is probably the more just idea of the two, as we find that the vessels, both veins and arteries, can give this disposition, and to a very great extent.f We find in the beginning of

* This is contrary to the disposition of inflammatory blood when taken out of the vessels and allowed to go through its spontaneous changes; from which it would appear that the general affection of the blood (which I would call sympathy of the coagulating lymph with the universal irritation), is different from its affection or disposition, when employed for the purposes of union.. f [We can have no difficulty in rejecting this opinion ; especially as it is opposed to the author's own observations elsewhere (p. 246 et passim) as well as the whole analogies of the subject (p. 314, note). The reason for assigning a *9* 338. HUNTER ON THE BLOOD. mortification the blood coagulating in the vessels, so as to fill them up entirely; and this, preceding the mortification, seems to be for the purpose of securing the vessel before it is to give way. We therefore cannot doubt of a coagulating principle being given to the blood from the vessels ; and, as a further proof of this, we may observe that the extravasated coagulating lymph, which produces either adhesions or forms tumours (which is often the case), is always of the nature of the diseased solids that produced it. If the case is venereal, the new substance is of the same nature: if cancerous, it is cancerous; for I find that it has, when absorbed, the' power of contaminating, similar to matter or pus produced by the sores or ulcers of such diseases; the absorbent glands being often affected by the absorption of the coagulating matter of a scirrhous breast. Whatever change the coagulating lymph has undergone in this operation of inflammation, it seems so far the same as to retain still the nature of the coagulating lymph, and to possess the living principle. This is most probably in a greater degree; and therefore the coagulating lymph is still better fitted to be formed into a part of the solids of the body, as will be taken notice of when we come to treat of the state of the blood in inflammation. But it is not absolutely necessary that the coagulating lymph should first undergo a change in the extravasated vessels before it can become a living solid, or unite living solids: for we find that common blood extravasated from a ruptured vessel is perhaps, equally efficacious in this respect; therefore the red globules do not retard union, but they may promote it.

§ 7. The state of the Blood and of the Pulse in Inflammation.

From what has been said of the living power of the blood, I think we must allow that it will be commonly affected much in the same manner with the constitution, and that disease will have nearly the same effect upon it as it has on the body, because the same living principle runs through the whole. We find this to be nearly the case: for till a disease has affected the constitution, the blood continues the same as before; but as the constitution becomes affected, the blood also becomes affected, and undergoes the same changes, which probably may be ascribed to contiguous sympathy between the vessels and the blood; and we shall find that the changes in the blood are often as much expressive of disease as any other part of the body. It is expressive of strong action as well as of weak action ; but as it does not give sensation it cannot convey to the mind all the varieties of disease that may take place in it; yet I could conceive, if the blood was to be primarily affected, that an impression would be made

different cause for the obliteration of the cavities of blood-vessels, than that which is employed by nature for the union of divided parts, derives no support from observation. The coagula which form in blood-vessels and anenrismal sacs is not found to form any vascular connexion with the containing parts.] THE ADHESIVE INFLAMMATION. 339 upon the mind, from its affecting the vessels in which it moved. However, it is not always the case that the state of the blood and the other symptoms are expressive exactly of the same thing; the blood often expressing less, and often more. When the action of the solids is of the inflammatory kind, or, which perhaps is the same thing, when there is too great an action of the solids, the blood more readily admits of a separation of its visible parts, and the coagulating lymph coagulates more slowly, but becomes firmer when coagulated. This last circumstance, however, might be supposed not to be so clear, for its firmness may be owing to its want of the red particles, which certainly give the blood a briuleness in proportion to their quantity ; but although this may have some effect, yet it is very little, for we find blood of loose texture in some inflammations when deprived of its red part. When blood has this disposition it is called sizy blood. These changes in the nature of the blood depend so much upon the above-mentioned causes of inflammation, that it is impossible to say whether they do not constitute the first universal effect produced from the local inflammation, and whether the constitutional is an effect of this change in the blood. I knew a man who was stabbed in the loins, and, according to the consequent symptoms, was most probably wounded or hurt in some viscus within the abdomen. At first he had no symptoms, but simple pain in the part; I therefore only bled him, by way of precaution, and the blood was perfectly natural; in less than a quarter of an hour after, constitutional symptoms came on, such as rigour, sickness, &c, and on opening the same orifice, and taking away more blood, this second quantity had a very thick and strong buff upon it, having all the appearance of inflammatory blood. While this constitutional disposition lasted, which was some time, his blood continued the same, which was proved by the subsequent bleedings. The subsiding, however, of the red globules in the blood when in an inflamed state, although pretty frequent, is not always an attendant, or, in other words (and perhaps upon some other principle), the blood is not always attended with this appearance, when the visible symptoms are the same. A young woman was attacked with a violent cough, oppression in breathing, quick, full and hard pulse. She was bled, which gave her ease: the blood was sizy ; the symptoms again returned, and she was bled a second time, which also relieved her, and the blood was more sizy than before; so far all the symptoms agreed. The symptoms again recurred, and were more violent than before: she was bled a third time, and a third time relieved; but this blood was not in the least sizy, although it came from the vein very freely. Here then the blood, under the same disease, lost this disposition, although the symptoms remained the same. As inflamed blood leaves a portion of the coagulating lymph free from the red globules at the top, and as that can be accounted for upon the principle of the coagulating lymph, in such cases, not coagulating so fast as when the blood has not this appearance, and 340 HUNTER ON THE BLOOD. as the coagulation hinders any comparative experiment respecting the weight of the red globules of each, I tried to see if they sunk in serum faster in the one kind of blood than in the other. 1 took the serum of inflammatory blood, with some of the red part, and also some serum of blood free from inflammation, with nearly the same quantity of the red part. They were put into phials of the same size; I shook them at the same time, then allowed them to stand quiet, and observed that the red globules subsided much faster in the inflammatory blood than in the other. To ascertain whether this arose from the red globules being heavier or the serum lighter, I poured off the serum from each, as free from red blood as possible; then put the red part of the one into the serum of the other, and shook them to mix them well; and, upon letting them stand quiet, the red globules appeared to fall equally fast. From these experiments it appears that the red part of imflammatory blood was heavier than that which was not so, and the serum was lighter, and the difference pretty nearly equal; for if we could suppose that the red globules were one-tenth heavier, and the serum one-tenth lighter, then the difference in the subsiding of the red globules of inflammatory blood in its own serum, to that which is not inflammatory, would be as one to five; and if they were to be changed, then they would be equal.* To see whether the blood from an inflamed part was different from that drawn from a part not inflamed, the following experiment was made: A large leech was applied to an inflamed surface, and when it had sucked itself full, another leech was suffered to fill itself from the breast where no inflammation existed. They were both cut in two, and the blood received into two teacups, kept moderately warm in a dish of warm water. Both of them coagulated without the serum separating; but the inflamed blood was evidently of a lighter colour than the blood from the uninflamed part, but neither had the appearance of a buffy coat. Whether the disposition for inflammation, and the change produced in the blood, arise from a real increase of animal life, or whether it is only an increase of a disposition to act with the full powers which the machine is already in possession of, is not easily determined; but it appears to be certain that it is either the one or the other. There are some circumstances, however, that would incline us to suspect it to be the latter, because there is often inflammation when the powers of the machine are but weak, where it appears to be only an exertion of very weak powers, arising from some irritation produced; in such cases the blood will show signs 'of weakness although sizy. This appears to be equally the case in local inflammation, and inflammatory fevers, or in the symptomatic

* [This accords with the fact before mentioned of the proportion of fibrin in inflamed blood being increased at the expense ofthe albuminous parts of the serum. The results often experiments on inflamed blood gave the following average, viz., 4-2 fibrin, and 3013 solid contents ofthe serum; the standard of health being respectively 28 and 42-2.—Thackrah, p. 212, and notes, pp. 44,.45.] THE ADHESIVE INFLAMMATION. 341 fever.* That it is an increase ofthe one or the other, and that the sensible effect produced arises from the action taking place, both in the solids and fluids, is proved by the method of treatment, which will be further illustrated in speaking of the mode of cure. On the other hand, where there is great debility in the solids, where the powers of preservation (the first animal powers) are weak, and therefore the action weak, and where of course the body must have a tendency to dissolution, there we find the very reverse of the former appearance in the blood; instead of separating distinctly, and coagulating firmly, we have the whole mass of blood keeping mixed, and hardly any coagulation, only becoming of a thicker consistence. This effect, or appearance, often takes place in those who die instantaneously. I suspect that in such cases the blood dies first, and also instantaneously. In the commencement of most diseases, and even through the whole course of many, the situation of the blood appears to be an object with Nature. In some the blood forsakes the skin and extremities, and we may suppose the smaller vessels in general; for when we can observe internal parts, so we find it, such as the mouth in general, eyes, &c.; a general paleness takes place, which is best seen in the lips, and even a shrinking of the external visible parts takes place, especially the eyes, so that the person looks ill, and often looks as if dying. The pulse is at this time small, which shows that the whole arterial system is in action. This appears to arise from debility, or the want of powers in the constitution to be acted on by such a disposition at the time, so that the whole powers or materials of life are called into the vital parts or citadel* and the outworks are left to themselves. Such is the case with fainting, the cold fit of an ague, the cold fit or beginning of a fever, and the rigors or beginnings of exacerbations: it is also the case with the hectic. In the commencement of diseases it does not appear to arise from real debility of constitution, but from the novelty ofthe action, and of course a debility in that action, and from that only; but in the hectic, where a real debility has taken place, those appearances are owing to that cause; however, even in the hectic, this debility is assisted by the unnaturalness of the action. In the first, where

* On the other hand it would appear reasonable to suppose that there was really an increase of animal life, for women who are breeding, and are in perfect health, always have sizy blood; and this is most remarkably the case with all animals in similar situations. Now it would appear necessary for an animal, whenever put into a situation where greater powers are wanted, to have these powers increased. In a breeding woman there is a process going on, though natural yet uncommon, and which requires a greater exertion, or a greater quantity of powers than usual, and therefore we have them produced. This process of breeding, although in many of its symptoms it is similar to fever, is yet very different; for actual fever kept up for nine months would destroy the person, while, on the other hand, many are relieved by the process of breeding. If these observations are just, this blood should not be called inflammatory blood, but blood whose powers of life are increased. 342 HUNTER ON THE BLOOD. there are real powers, it would appear as if Nature was struggling with the new disposition, and it either becomes destroyed entirely or in part, and the blood is then determined to the skin, and we may suppose into the smaller vessels in general; then the pulse becomes full; the whole action now appears to be there [in the skin], and it becomes hot; when that action in the skin ceases a perspiration takes place, and Nature seems in many cases to be at rest; in some disorders this cessation is perfect for a time, as in agues; sometimes wholly, as in slight colds; but often imperfectly, as in continued fevers, where the cessation appears only to arise from weariness, which prevents the continuance of the action, not from an alteration of the disposition. In other diseases the blood is thrown very early upon the exterior parts. The face shall look bloated, the eyes full, the skin red, dry, and hard to the touch. These symptoms, I suspect, belong more to fevers of the putrid kind, and have less connexion with surgery than the former. The pulse is often as strong a sign of the state of the constitution as any other action that takes place in it, though it is not so always; but as the pulse has but one circumstance attending it that we can really measure, all the others being referrible to the sensation or feeling of the person who is to judge of it, the true state of' the pulse is not easily ascertained. The knowledge of the soft, the hard, and the thrilling, are such as can only be acquired with accuracy by the habit of feeling pulses in these different states, and by many is not to be attained, for simple sensation in the minds of any two men are seldom alike. Thus we find it happens with respect to music, for what would be disagreeable, and not in harmony to one ear, which is nice and accustomed to the harmony of sounds, will not be so to another. The late Dr. Hunter was a striking instance of this, for though he was extremely accurate in most things, he could never feel that nice distinction in the pulse that many others did, and was ready to suspect more nicety of discrimination than can really be found. Frequency of pulsation in a given time is measurable by instruments; smartness or quickness in the stroke, with a pause, is measurable by the touch ; but the nicer peculiarities in the pulse are only sensations in the mind. I think I have been certain of the pulse having a disagreeable jar in it when others did not perceive it, when they were only sensible of its frequency and strength ; and it is perhaps this jar that is the specific distinction between constitutional disease, or irritation and health; frequency of pulsation may often arise from stimulus, but the stroke will then be soft; yet softness is not to be depended on as a mark of health ; it is often a sign of dissolution; but then there must be other attending symptoms. In the consideration of the peculiarities of the pulse it is always necessary to observe, that there are two powers acting to produce them, the heart and the arteries; that one part of the pulse belongs to the heart alone, another to the arteries alone, and the third is a compound of both; but the actions of the heart and arteries do THE ADHESIVE INFLAMMATION. 343 not always correspond; the heart may be in a state of irritation, and act quickly in its systole, while the arteries may be acting slowly; for the heart is to be considered as a local part, while the vessels must be considered as universal, or even constitutional. The stroke (which is the pulse), with the number of them that are made in a given time, whence the pulse is commonly called quick or slow, their regularity and irregularity as to time, and the quickness of the stroke itself, belong to the heart. The quickness of the heart's action often takes place, although the pulsations are not frequent, which gives a kind of rest or halt to the artery or pulse, especially if the pulse be not frequent. The hardness, the vibratory thrill, the slownessof systole, with the fulness and smallness of the pulse, belong to the arteries. As the pulse arises from the actions of the solids or machine, its state will be of course according to the nature ofthe machine at the time, and therefore is capable of being in one of these states,—natural or diseased. In most diseases of the constitution, whether originating from it, or arising in consequence of diseases of parts, where the constitution becomes affected by sympathy, the pulse is altered from a natural to a diseased state, the degree of which will be regulated by those affections. This alteration is commonly so constant, and so regularly of the nature of the disease, that it is one of the first modes of intelligence we have recourse to in our inquiries into its nature; but alone it is not always a certain guide, for where there are peculiarities of constitution we find the pulse corresponding to those peculiarities, and perhaps in direct contradiction to the accustomed state of the local affection. The same parts, too, under disease, give very irregular or uncertain signs in the actions ofthe heart and vessels, such as diseases or injuries done to the brain. The varieties which the pulse admits of are several. It is increased in its number of strokes, or it is diminished ; it is regular or irregular, as to time, in its stroke; it is quick in its stroke or diastole, and slow in its systole; it is hard in its diastole, and it vibrates in its diastole. In most cases, probably, where the constitution is in a state of irritation, the pulse will be quick and frequent in its number of strokes in a given time, and the artery will become hard from a constant or spasmodic contraction of its muscular coats, so as to give the feel of hardiness to the touch; besides which the diastole of the artery is not regularly uniform and smooth, but proceeds by a vast number of stops or interruptions, which are so quick as to give the feel of vibration, or what we would express by a thrill. The pulse, under such a disposition or mode of action may be either full or small. These two very opposite effects do not seem to arise from a difference in the quantity of blood, which might at first be supposed; I should rather suspect that they arise from a difference in the degrees of strength; which will be more or less, according to the nature of the parts inflamed, and the degree of irritability of the patient at the time. These give, more or less, an anti-diastolic dis- 344 HUNTER ON THE BLOOD. position to the arteries ; and while the arteries have the power of contraction, and are in a state of irritation, this effect will always take place. It is certain, at least, that the arteries do not commonly, in such a state of constitution, dilate so freely and so fully as at other times; and as this will vary very quickly (if the constitutional irritation varies quickly,) it is more reasonable to suppose that it is an immediate effect of the arteries, than an increase and decrease of the quantity of blood. If this be really the case, then we should naturally suppose that the motion of the blood in the arteries would be increased in proportion to their diminished size; except we should also suppose that the diastole, or the systole or contraction of the heart, is also diminished in the same proportion. The first of these, I think, may probably be the case, as we find that the blood forsakes the surface of the body in such a state of the constitution, as will hereafter be observed, and therefore must be collected in the larger veins about the heart. If the heart was to dilate [as usual] and throw out its whole contents at each systole, then the velocity of the blood in the arteries, under such a state of contraction of arteries, would be immense, and it might then be pushed into the smaller vessels on the surface of the body, which it certainly is not. The quick, hard, and vibratory pulse is generally an attendant upon inflammations, and whether it be attended with fulness, or the contrary, depends a good deal upon the part that is inflamed, which either increases or decreases the irritability, which will be described in treating ofthe different parts inflamed. In such a state of the constitution as produces such a pulse, the blood, which appears to be only a passive body, acted upon by the heart, so as to produce the diastole of the artery, and reacted on by the vessels, making the complete pulse, this blood, I say, is generally found in a different state from that where there are not these symptoms in the pulse; they, as it were, constantly attend each other, or are the reciprocal causes and effects of one another, as was taken notice of when I was speaking of the state of the blood in inflammation. From the account I then gave of the state ofthe blood in inflammation, and have now given of the pulse, under the same action, it should naturally be expected that they should explain each other, which, for the most part, they certainly do ; yet these appearances of the blood, and the kind of pulse, are every now and then appearing to be in opposition to each other in their common attending circumstances; but this cannot be known till the person is bled. When the pulse is quick and hard, with a kind of vibration in the action, we generally have sizy blood. This may arise from fever, or such inflammation, etc., as affects the constitution or vital parts, these being so diseased as to keep up a constitutional irritation, which will always be an attending symptom ; but when we have neither a quick nor hard pulse, hut both, perhaps, below par' and rather small, with no visible fever nor inflammation, but probably some strong, undetermined symptoms, such as pain, which is movea- THE ADHESIVE INFLAMMATION. 345 ble, being sometimes in one place, sometimes in another, but at the same time seeming to impede no natural function, yet upon bleeding the blood shall be sizy, and the size shall have strong powers of contraction, so as to cup. A gentleman was ill with a pain, chiefly in his right side, but upon the part being rubbed, or upon applications being made to it, the pain seemed to move to some other part, from which circumstance it was supposed to have connexion with the bowels : at other times he was tolerably well. His pulse was slow, small, and soft, and not at all, to the feel, like a pulse which required bleeding. He desired to be bled, and when bled the blood was extremely sizy, the size being strong, and contracting so much as to draw in the edges, forming the upper surface into a hollow or cup. His pulse became fuller, quicker, and harder ; he was bled a second time ; the blood was the same, and the above symptoms increased so much that I observed, immediately after the second bleeding, his pulse was quicker, harder, and fuller than it was just before the bleeding. That it might be quicker and fuller I could conceive, because I have often seen such effect from bleeding where there had been an oppressed and languid pulse ; but I cannot say that I ever saw a case where the pulse became harder, and acquired the vibration, except when debility or languor was produced, and where the blood was weak in its powers of coagulation, being flat on the coagulated surface.* Another want of correspondence, or irregularity, takes place when a constitution sympathizes with a local inflammation. There are cases where the pulse becomes slow, and often irregular; such are mostly to be found in old people, when the constitution is affected either originally or sympathetically, and in such 1 suspect that a disposition for dissolution, and perhaps mortification, is much to be feared. A man, aged sixty-eight'years, had an occasional inflammation in one of his legs, which often ulcerated, and which seemed to arise more from a defect in the constitution than to be simply local. In those indispositions his pulse seldom exceeded forty in the minute; and as he began to get better his pulse became more and more frequent. The varieties of the pulse, arising from the seat of the inflammation and the nature of the part inflamed, will be explained when I treat on inflammations in different situations and parts.

§ 8. The effects of Inflammation on the Constitution, according to the structure of parts, situation of similar structures, and whether vital or not vital.

These circumstances make a very material difference in the effects on the constitution arising from local inflammation ; for we

* [See Principles of Surgery, p. 304; and Dr. Marshall Hall, on the Effects of Loss of Blood, in Med, Chir. Trans., vol. xvii.] 30 346 HUNTER ON THE BLOOD. shall find that the effects on the constitution are not simply as the quantity of inflammation, but according to the quantity and parts combined, (supposing constitutions to be equal,) which I shall now consider separately. In common parts, as muscle, cellular membrane, skin, &c, the symptoms will be acute, the pulse strong and full, and the more so if it be felt near to the heart; but perhaps not so quick as when the part is far from it, since there will be less irritability. The stomach will sympathize less, and the blood will be pushed further into the smaller vessels. If the inflammation is in tendinous, ligamentous, or bony parts, the symptoms will be less acute, the stomach will sympathize more, the pulse will not be so full, but perhaps quicker, because there will be more irritability, and the blood will not be so much pushed into the smaller vessels, and therefore forsake the skin more. It seems to be a material circumstance whether the inflammation is in the lower or upper extremity, that is, far from or near to the heart; for the symptoms are the more violent, the constitution is more affected, and the power of resolution seems to be less when the part inflamed is far from the source of the circulation than -when near it, even when parts are similar both in texture and use. Whatever course the inflammation is to run, or in whatever way it is to terminate, it is done with more ease when near to the heart than when far off. All the parts that may in one sense be called vital do not produce the same effects upon the constitution ? and the difference seems to arise from the difference in their connexions with the stomach. It is to be observed that vital parts may be divided into two, one of which is in itself immediately connected with life, as the stomach ; the other, where life only depends upon it in its action or use. The heart, lungs, and brain, are only to be considered in this last light; and therefore they have a considerable sympathizing affection with the stomach: the symptoms are rather depressing, the pulse is quick and small, and the blood is not pushed into the smaller vessels. If the heart or lungs are inflamed, either immediately, or affected secondarily as by sympathy, the disease has more violent effects upon the constitution than the same quantity of inflammation would have if it was not in a vital part, or was in one with which the vital parts did not sympathize ; for if it is such as the vital parts sympathize with readily, then the sympathetic action of the vital parts will affect the constitution, as in an inflammation of the testicle. In such cases the pulse is much quicker and smaller than when in a common part, as a muscle, cellular membrane, or skin; but not so much so as in the stomach, and the blood is more sizy. When the inflammation is in the heart only, its actions are extremely agitated and irregular. If in the lungs, singly, the heart in such cases would appear to sympathize, and not allow of a full or free diastole. The stomach does not in common sympathize in such cases, which is the reason perhaps of the inflammation not depress- THE ADHESIVE INFLAMMATION. 347 ing; but it is to be observed that I make a material difference between the inflammation ofthe lungs, commonly called a pleurisy, and those diseases that begin slowly and spin out to great lengths, and which are truly scrofulous, producing the hectic, for in them we have the hectic pulse and not the inflammatory. If the stomach is inflamed, the patient feels an oppression and dejection through all the stages of the inflammation ; simple animal life seems to be hurt and lessened, just as sensation is lessened when the brain is injured; the pulse is generally low and quick, the pain is obtuse, strong, and oppressing, such as a patient can hardly bear.* If the intestines are much affected, the same symptoms take place, especially if the inflammation be in the upper part of the canal; but if it .is the colon only which is effected the patient is more roused, and the pulse is fuller than when the stomach only is inflamed. If it be the uterus, the pulse is extremely quick and low. If it be a testicle that is inflamed, the pain is depressing, the pulse is quick but not strong. When the inflammation is either in the intestines, testicle, or uterus, the stomach generally sympathizes with them, which will produce or increase the symptoms peculiar to the stomach. In inflammation of the brain, I believe, the pulse varies more than in inflammations of any other part; and perhaps we are led to judge of inflammation there more from other symptoms then the pulse. I believe the pulse is sometimes quick, slow, depressed, full, &c, and which may accord with the other symptoms, such as delirium, stupor, &c. It is to be observed, when the attack upon these organs (which are principally connected with life) proves fatal, that the effects of the inflammation upon the constitution run through all the stages with more rapidity than when it happens in other parts; so that at its very beginning it has the same effect upon the constitution which is only produced by the second stage of fatal inflammation in other parts. Debility begins very early, because the inflammation itself is interfering immediately with the actions of life ; and also in such parts universal sympathy takes place more readily, because the connexion of these parts by sympathy is more immediate ; and if the sympathy is similar to the action, then the whole is in some degree in the same action. If the inflammation comes on in a part not very essential to life, and with such violence as to affect the actions of life or to produce .universal sympathy, the pulse is fuller and stronger than common ; the blood is pushed further into the extreme arteries than when the inflammation is in a vital part; the patient, after many occasional

* [It may be asked, if inflammation consists of an increase of animal life, or of a disposition to act with all the powers of which the machine is possessed, how comes it to pass that inflammation of the stomach produces such depressing effects ?] 348 HUNTER ON THE BLOOD. rigors, is at first rather roused, because the actions of the part are roused; and the effects in the constitution are such as do not impede any of the operations of the vital parts. It is allowed to proceed to greater lengths, or greater violence in itself, before the constitution becomes equally hurt by it; and the constitutional symptoms produced at last may be said to arise simply from the violence of the inflammation. But this will take place more or less according to circumstances: it will be according to the nature of the parts, whether active as muscles, or inactive as tendons; also according to the situation of the same kind of parts, as well as according to the nature of the constitution. If the constitution is strong and not irritable, the pulse will be as above ; but if the constitution is extremely irritable and weak, as in many women who lead sedentary lives,'the pulse may be quick, hard, and small at the commencement of the inflammation, similar to what happens in the inflammation of vital parts. The blood may be sizy, but will be loose and flat on the surface.

§ 9. General Reflections on the Resolution of Inflammation.

I now come to the most difficult part of the subject, for it is much more easy to describe actions than to assign motives;* and without being able to assign motives, it is impossible to know when or how we may or should check actions, or remove them. I have endeavoured to show that an animal body is susceptible of impression producing action ; that the action, in quantity, is in the compound ratio of the impression, the susceptibility of the part, and the powers of action of the part or whole; and in quality that it is according to the nature of the impressing power and the parts affected. I have also endeavoured to show that impressions are capable of producing or increasing natural actions, and are then called stimuli; but that they are likewise capable of producing too much action, as well as depraved, unnatural, or what are commonly called diseased actions. The first of these I have mentioned by the general term, irritations ; the depraved, &c, come in more properly in treating of peculiar or specific actions. Since, then, an animal body can be made to increase its natural action, or to act improperly by impression, so we can see no reason, when it is acting too violently, why it should not be restrained by impression; or when acting improperly, in consequence of these impressions, why it should not be made to act properly again by the same mode, namely, by impressions. These modes of action we are first to understand, and then the power of correcting or counteracting those impressions, in order to diminish or prevent the action, so as to produce one that is healthy or natural. Besides, an.injury which produces a new mode of

* [By " motives" the author must here be understood to mean all the causes of inflammation, whether original or modifying.] THE ADHESIVE INFLAMMATION. 349 action, and a disease, which is a new mode of action, often happen when the machine is in perfect health, and in such a state as is perfectly in harmony with that health; but which state is not suitable to disease. Therefore it is to be presumed the more perfect health the body enjoys the less it bears a change in its actions. Thus we know that strong health does not bear considerable injuries, such as accidents, operations, &c. A man in strong health, for instance, will not bear a compound fracture in the leg, or an amputation of the same, so well as a man accustomed to such diseases and reduced by them. We find, commonly, that our artificial mode of reduction is by far too quick, and is almost as much a violence on the constitution as the injury ; when therefore considerable injuries or diseases commence, the constitution is to be brought to that state which accords best with that accident or disease [see p. 272]. The knowledge of that state of the body at that time, as well as of the operations of the whole animal, or of its parts, when arising from a disturbed or deranged state, or a diseased disposition, are to be considered as the first steps towards a rational cure. But this alone is insufficient: the means of bringing the body to that state are also necessary, which will include the knowledge of certain causes and effects, acquired by experience, including the application of many substances, called medicines, which have the power of counteracting the action of disease ; or of substances perfectly inefficient in themselves, but capable under certain circumstances of producing considerable eflects, such as water when hot and cold, or a substance when it varies its form, as from fluidity to vapour. Of these virtues we know nothing definitely : all we know is, that some are capable of altering the mode of action, others of stimulating, many of counter-stimulating, some even of irritating, and others of quieting, so as to produce either a healthy disposition and action in a diseased part, or to change the disease to that action which accords with the medicine, or to quiet where there is too much action ; and our reasoning goes no further than to make a proper application of those substances with these virtues. The difficulty is to ascertain the connexion of substance and virtue, and to apply this in restraining or altering any diseased action ; and as that cannot be demonstrated & priori, it reduces the practice of medicine to experiment, and this not built upon well-determined data, but upon experience, resulting from probable data. This is not equally the case through the whole practice of medicine, for in many diseases we are much more certain of a cure than in others; but still, even in them, the certainty does not arise from reasoning upon any more fixed data than in others where the certainty of a cure is less, but it arises from a greater experience alone: it is still no more than inferring, that in what is now to be tried, there is a probable effect or good to arise in the experiment, from what has been found serviceable in similar cases. Diseases, 30* 350 HUNTER ON THE BLOOD. however, ofthe same specific nature, not only vary in their visible symptoms or actions, but in many of those that are invisible, arising probably from peculiarities of constitution and causes, which will make the effects of applications vary probably almost in the some proportion; and as those varieties cannot be known, so as either to adapt the specific medicine to them, or to suit the disease to the medicine, it will then be only given upon a general principle, which of course may not correspond to the peculiarities. Even in well-marked specific diseases, where there is a specific remedy, we find that there are often peculiarities which counteract the simple specific medicine. This we even see in poisons, which produce the simplest instances of specific disease, because the effects always depend on the same causes.* The peculiarities therefore in the disease must arise from a peculiarity in the constitution and not from the cause of the disease. The inflammation 1 have been treating of is the most simple of any, because it is the simple action of the parts unmixed with any specific quality, arising from causes of no specific kind, and attacking constitutions and parts not necessarily having any specific tendency. The cure, therefore, or method of terminating the inflammation, which is called resolution, (in cases that will admit of it,) must also be very simple, if we knew it; and accordingly, when the cure of such is known, it lays the foundation of the general plan for the treatment of all inflammations of the same kind. But it very rarely happens that a constitution is perfectly free from a tendency to some disease;f we seldom therefore see simple salutary actions of parts tending to relieve themselves from a violence committed : some constitutions being so irritable that the inflammation has no disposition to terminate, and others so indolent that the inflammation passes into another species, as into scrofula; all of which will require very different treatment. The same varieties take place in specific inflammations, as also in inflammations arising from poisons; for many will have the true inflammatory disposition joined with the specific. In such therefore the same plan is to be pursued, with the addition only of the specific treatment; but this must not be omitted, as the inflammation depends upon the specific disease. It is this critical knowledge which becomes the basis of practice, and it is this which requires the greatest sagacity; and I must own it requires more knowledge than comes to the share of most practitioners. As every inflammation has a cause, that cause should be removed before resolution can take place; for the animal ceconomy having a disposition within itself to discontinue diseased action, that of course subsides upon the removal of the cause, and this disposition is so

* [The passage in the original text runs thus: "This we even see in poisons, the most simple specific of all, because its effect arises in all cases from one cause."] f Vide the varieties ofthe inflammation, in the Introduction. THE ADHESIVE INFLAMMATION. 351 strong in some as to appear to act alone. That removing the cause is a mode of resolution is proved in the venereal bubo; for by taking off the venereal action with mercury, the inflammation subsides, if another mode of action does not arise.* Inflammation, where it must suppurate, is most probably a restorative act, and cannot be resolved in those cases where restoration becomes necessary: as, for instance, in a wound that is kept exposed, the inflammatory act of restoration becomes or is rendered necessary, and it takes place ; but bring those parts together, or let the blood coagulate and dry upon it, and it becomes unnecessary. I have already observed when treating of the causes of inflammation, which might be called the spontaneous, that they probably arose from a state of parts in which they could not exist, similar to exposed surfaces, and therefore this act of restoration became necessary. If this be true, then probably by altering that state of parts, as we can [in the latter instances] by bringing the divided parts together, the inflammation would either not rise or immediately cease; but as we are not in all cases acquainted with the mode of restoring those natural actions, we are obliged to be restricted to those methods that render them easier under this state, and which are often capable of turning the balance in favour of resolution. As inflamed parts are not always visible, it becomes necessary that we should have some rule to inform us whether the part is inflamed or not; to ascertain which we must have recourse to all the symptoms formerly mentioned, except the visible ones. We ought also to have a guide respecting the kind of inflammation, more especially as it is not sufficient, in many cases, to be guided entirely by its appearances, even where it is in sight. It is often therefore very necessary to inquire into the cause of the inflammation, the nature of the constitution, the effects that former inflammation has produced, and even into the temper and mind ofthe patient. The cure of inflammation is resolution, and the attempt towards it is principally to be made when the inflammation is in the adhesive state: for we find that often it goes no further, but subsides, and this is resolution. Probably the sooner [the attempt is made] after its commencement the better it is. The object of the attempt is to prevent suppuration taking place, although suppuration may be considered as a resolution; but it is the mode of resolution we commonly wish to avoid. Resolution is in general only to be attempted, with any probability of success, under the following circumstances, viz., first, when the inflammation is in consequence of the constitution, or a disease of the part; secondly, in cases of accident where there is either no exposure, or where it has been removed in time, as, for example, by bringing the parts in contact; thirdly, where the life of the part has not been destroyed. In all such cases we find that resolution can take place; but in

* Vide Treatise on Venereal Disease. 352 HUNTER ON THE BLOOD. those cases arising from accident and a continuance of exposure joined, or where death of the parts is produced by the accident, it becomes impossible to hinder the suppuration from taking place. I have already observed, that in many bruises, as well as simple fractures, where the cavities are not exposed, and where they are to heal by the first and second intention, the inflammation, in most of these cases, is capable of being resolved, although in some such cases the inflammation runs so high as to threaten suppuration. I have also already shown that, in parts which have been divided and exposed, the inflammation is, in a great measure, prevented by bringing them together; or, if it has taken place previous to the union, that the same operation of union is sufficient to produce resolution: and I have likewise shown, that where parts were not brought together, Nature attempted to prevent inflammation by covering the wound with blood and forming an eschar, which in many cases will either prevent or remove inflammation; all of which shows a power of resolution even in cases where the parts have been exposed. As it is commonly supposed that there are a great many local diseases that should not be resolved, the first thing necessary to be considered is when the resolution should or should not be attempted. On the contrary, there are cases where inflammation is to be excited ; but these arise commonly from disease, which is not to our present purpose. Yet it sometimes happens in accidents, where inflammation is necessary, that it is not sufficient for the reinstatement of the injured parts, as in some simple fractures, where the first bond of union, the extravasated blood, had not fulfilled its purpose, and had been absorbed, and where the inflammation was too slight to supply its place ; so that the union of parts being prevented, another mode became necessary, not at all a consequence of inflammation, viz., by granulations without suppuration ;* all of which retard still more the restoration of the parts. As this defect can only be known in bone, and in the soft union of the bone, which is similar to the union in the soft parts, it is reasonable to suppose it may also take place in the soft parts, more especially those which are tendinous or ligamentous, where we find recovery very slow, for the soft union in bones differs in nothing from that of the soft parts; it may therefore be a much more common defect than is generally imagined. In such cases, if it could be known, it would be proper to encourage or even excite inflammation. If we cannot probably in any case determine where it should be excited, nor even where it should be checked, yet we can say in many cases where it is unnecessary to check it. Before we attempt to check inflammation, we should have reason to suppose it is going further than is necessary for the natural cure, and that it is therefore laying the foundation of work for the surgeon. It may be very difficult to say, in many cases, when it * See Principles of Surgery, p. 203. THE ADHESIVE INFLAMMATION. 353 should be checked. The most simple reason will be to lessen pain, arising in a part not merely when moved or touched, but from the act of inflammation. Secondly, where it may be uniting parts, the union of which we wish to avoid; but this is an uncertain guide, even if we knew adhesions were taking place, for adhesions often prevent suppuration. Thirdly, to prevent the inflammation from suppurating; and in this last, although the most obvious, yet there is less certainty how far we may advise the attempt. It is also the most difficult to effect; for in many cases of spontaneous inflammation, if it arises from a state under which the parts cannot exist nor their functions go on, similar to an exposed breach in the solids, then resolution should not be attempted. It may be palliated when going beyond what is necessary for suppuration; but when this practice is carried further, it r.ther retards that salutary process. From the foregoing statement of particulars it must appear that in many cases it is unnecessary to check inflammation, in others it would be wrong, and in many very necessary; and probably the best guide is its going further than appears, from the [nature of the] cause, to be salutary. Yet in practice we find applications, and other modes of resolution, immediately had recourse to, which must be considered as opprobrious to surgery. Inflammations, in consequence of accidents, ought in general to be resolved, if possible. It is perhaps impossible to produce a single instance where a contrary practice would be preferable, except as above related, where its consequence would be to answer some great purpose: and it is also conceivable that this local disease, produced by accident, might relieve the constitution from some prior disorders, similar to what is understood to be the effects of an issue. Mr. Foote was relieved of headache, of long standing, by the loss of a leg, which may be considered as a proof of this; but he afterwards died of a complaint in his head, very similar to an apoplexy. It might be supposed, on the other hand, that the temporary cure was,the cause of the apoplexy. Inflammation, in consequence only of a disease in a part, appears to be under the same circumstances with respect to resolution; but an inflammation arising from a preceding indisposition in the constitution (commonly called critical) has always been classed among those which should not be cured locally, and this has got the term of repulsion: it has been insisted on that the inflammation should rather be encouraged, and suppuration produced if possible. If the inflammation is really a concentration of the constitutional complaint, and that by not allowing it to rest here, the same disposition is really diffused over the whole animal again, and at liberty to fix on some other part, it certainly would be better to encourage its stay; but in such cases it is always to be understood that the inflammation is in such parts as will readily admit of a cure when suppuration takes place; for if the disease be otherwise situated, then the cure ofthe constitution by suppuration will be a mode of cure which will reflect back another disease upon it, under which 354 HUNTER ON THE BLOOD. it will sink: resolution of inflammation, therefore, in the first of these situations, should if possible be brought about. For instance, many deep-seated inflammations, if allowed to suppurate, would of themselves most certainly kill. This might be illustrated by the gout, when either in the head or stomach, for when in such parts it had better be repelled, and left to find another part less connected with life, which, if in the feet, would be called repelling of it; but still it does not appear to me necessary that it should suppurate, for suppuration is only a consequence of the inflammation, and not an immediate consequence of the original or constitutional disease, but a secondary one :* as suppuration, therefore, is only a thing superadded, and as we shall find that inflammation generally subsides when suppuration comes on, I see no reason why inflammation, in the present case, should not as well subside by resolution as by suppuration; however, it may be supposed that although suppuration is not the natural or immediate effect ofthe disease, yet as it is a continued local action, and the thing sought for by the constitution, and as inflammation must precede it, the parts must submit to those regular processes, for it must be supposed to be capable of diverting the disease to this part.

§ 10. Ofthe Methods of Resolution by constitutional means.

The first thing to be considered is the kind of inflammation, when visible, which will in some degree show the kind of constitution ; the next is the nature of the part inflamed, and the stage of inflammation ; for upon these depend in some measure the method of relief. In cases of exposed internal surfaces the inflammation cannot be resolved, because the cause still exists till inflammation has resolved itself; but it may be lessened, and this probably takes place by lessening everything which has a tendency to keep it up ; and in all likelihood little more can be done in spontaneous inflammations; for as yet we know of no method which will entirely quiet or remove the inflammatory disposition or mode of action, as there is no inflammatory specific with which we are acquainted. When I described inflammation I observed there was either an increase of life, or an increased disposition to use with more violence the life which the machine or the part was in possession of; and also there was an increased size of vessels, and of course an increased circulation in the part inflamed, and in the constitution in general. If this theory of the mode of action of the vessels in inflammation is just, then our practice is reducible to two princi-

* This is contrary to the common received opinion, but it is according to my idea of suppuration ; for I have all along considered inflammation as the disease, and suppuration only as a consequence of that disease, and have supposed the disease to be gone when suppuration has taken place; but, according to the common opinion, suppuration was the thing to be wished for, because all diseases arose from humours; but as we have not once mentioned humours, and therefore made it no part of our system, we must also drop it at present. THE ADHESIVE INFLAMMATION. 355 pies, one consisting in removing the cause of that action, the other in counteracting the effects. As to the first, as we seldom know the cause, but only see the effect, except in some specific diseases, for which we have a specific remedy, we do not know with any degree of certainty how to act; but as to the second, that is, the effect, as it is more an object of our senses, we can apply with more certainty our reasoning upon it, for reasoning from analogy will assist us in our attempts. We find, from common observation, that many circumstances in life, as also many applications to parts, will call forth the contraction of the vessels ; we are, therefore, from the above theory, to apply such means: and whatever will do this, without irritation, will so far counteract the effect.* I have already observed, that wherever there has been a violence committed, or some violent action is going on, there is a greater influx of blood to that part. Lessening, therefore, that influx, becomes one mode of relief, for as the vessels dilate, they should not be encouraged in that action. Although the increased influx is to be considered chiefly as an effect, yet it is to be considered as a secondary cause ;f and from our ignorance ofthe immediate cause, it is probably only through such secondary causes that we can produce any effect; and upon these principles most likely rests, in some measure, the method of resolution, for whatever will lessen the power and disposition will also lessen the effect, and possibly these will likewise lessen the force of the circulation. If the inflammation is attended with considerable action and power, as it were, increasing itself, then the modes of resolution are to be put in practice ; the one by producing a contraction of the vessels, the other by soothing or lessening irritability, or the action of dilatation.:}: The first, or contraction of the vessels, is produced in two ways; one by producing weakness, for weakness excites the action of contraction of the vessels; the other, by such applications as induce the vessels to contract. 1st. The means of producing absolute weakness are bleeding and purging; but the bleeding also produces irritability for a time, and is often attended by a temporary weakness of another kind, viz.,

* As this is a new theory ofthe action of the vessels in inflammation, and the only one that can possibly direct to a method of cure, it is to be hoped that attention will be paid to it, and if just, that more certain methods of resolution will be discovered. • t [This is consistent with Mr. Hunter's language elsewhere, where he says that he "could conceive a part to inflame, or be in a state of inflammation, although no blood were to pass" (p. 311); but it is difficult to imagine the propriety °of calling that a cause which is the essential part of the thing intended. Inflammation could not exist, or certaihly could not be defined, without taking into account the augmented influx of blood.] ± [The reader will observe that an hypothesis is involved in this expression which does not appear to be supported by any substantial facts. That vessels presumed to be contractile should yet actively dilate under increased action, seems not only to imply a contradiction in terms, but to be wholly unsupported by any other consideration.] 356 HUNTER ON THE BLOOD. sickness. The inconvenience, however, arising from this practice is, that the sound parts must nearly, in the same proportion, suffer with the inflamed,for by bringing the inflamed part upon a par with health, the sound parts must be brought much lower, so as to be too low. 2d. The soothing may be produced by sedatives, relaxants, anti-stimulants, etc., such as many sudorifics, anodynes, etc. The first method will have the greatest, the most permanent, and the most lasting effect, because, if it has any effect at all, the diseased action cannot be soon renewed. The second will act as an auxiliary, for so far as irritation is a cause this will also lessen it, and the two should go hand in hand; for wherever we lessen power, we should at the same time lessen the disposition for action, or else we may increase the disposition; but neither bleeding, purging, nor sickness can possibly lessen the original inflammatory disposition [Principles of Surgery, p. 91], for none of them will resolve a venereal inflammation when mercury will; nor will they resolve the erysipelatous inflammation, although that inflammation has the very action for which we should bleed in the common inflammation, viz., dilatation of vessels. However, these means may, in some sense, be reckoned direct, for whatever will produce the action of contraction in the vessels is counteracting the action of dilatation. Lessening the power of action belonging to any disposition can only lessen or protract the effects, which, however, will be of singular service, as less mischief will be done, and it will often give the disposition time to wear itself out. Means employed on this principle should be such as give the feel of weakness to the constitution, which will affect the part, and will make the vessels contract; but this practice should not be carried so far as to produce the sense of too much weakness, for then the heart acts with great force, and the arteries dilate. Bleeding then, as a general principle, is to be put in practice, but this must be done with judgment, for I conceive the effects of bleeding to be very extensive. Besides, the loss of any quantity of blood being universally felt, in proportion to the quantity lost, a universal alarm is excited, and a greater contraction of the vessels ensues, than simply in proportion to this quantity, in consequence, as it would appear, of a sympathetic affection with the part bleeding.* Too much blood in an inflammation is a load upon the actions of the circulation. Too little produces debility and irritability, because thete is a loss of powers, with an increased action to keep up, which is now not supported. It would seem that violent actions of a strong arterial system required less blood than even the natural

* [This effect is with more probability to be ascribed to the approach of the state of syncope, which state, it may be observed, is often signally beneficial in the incipient stages of inflammation ; not merely by its tendency "to lessen and protract the effects," but by cutting short and at once removing the diseased action. The dangers or ill effects of blood-letting lie principally on the side of delay and too frequent repetition, and less in having vigorous recourse to this remedy in the first instance.] THE ADHESIVE INFLAMMATION. 357 actions, and even less still than a weak or irritable system ; from whence we must see that bleeding can either relieve inflammatory action or increase it, and therefore is not. to be used at random. As many patients that seem to require bleeding have been already bled, it may not be improper to inquire how they bear, or are affected by bleeding, for certainly all constitutions (independently of every other circumstance), do not bear this evacuation equally, and it is probable that its effects on inflammation may be nearly in - the same proportion ; if so, it becomes a very useful caution; for although the loss of blood may, as a general principle, be set down as a weakener, and probably the greatest, as we can kill by such means, yet the loss of certain quantities in many constitutions is necessary for health : this is either when there is a disposition to make too much blood, or a constitution that cannot bear the usual quantity ; in such, when known, bleeding with freedom is certainly necessary. If the inflammatiQn is known to be attended with real powers bleeding is absolutely necessary, in such quantity as to take off from the force of the circulation, which arises from too much blood; or if that is not sufficient, then as much as will cause a contraction of the vessels ; but in cases of too great an action of weak parts, then the proper quantity to be taken is no more than may assist the dilatation of the vessels, which will lessen the violence of motion in the blood, or remove the sensation in the part inflamed, of having too much to do :* the quantity, therefore, must be regulated according to the symptoms and other circumstances; for instance, according to the visible indications. We are to remark here, that every part of the body under inflammation will not bear bleeding alike. I believe that the constitution bears bleeding best when the inflammation is in parts not vital, and those near the source of the circulation ; whatever disturbs some of the vital parts, depresses, but not equally in all; and in them it becomes more necessary to be particular ; for in accidents ofthe brain, bleeding freely, even so as to produce sickness and fainting, is necessary. It is probable that the sickness attending such accidents is designed to lessen the influx to the head, and occasion the vessels of the brain to contract. The indications for bleeding are, first, according to the violence of the inflammation, joined with the strength of the constitution, which will in general point out the kind of inflammation. Secondly, according to the disposition to form much blood ; thirdly, according to the nature of the part, whether vital or not; fourthly, according to its situation, in point of distance from the heart; fifthly, according to the effect of the inflammation on the constitution.t With regard to this evacuation, it is worthy of particular consideration, whether or not, in all cases where it can be put in prac-

* [These modes of expression, which are evidently unphilosophical, have been already noticed. For the word "assist" in this paragraph, I should apprehend we ought to read relieve.] | [See note, Principles of Surgery, p. 182.] 358 HUNTER ON THE BLOOD. tice, bleeding in or near the part will answer better than taking the blood from the general habit, for certainly less may be removed in this way, so as to have equal effect upon the part inflamed (and probably upon every other disease that is relieved by bleeding), and yet affect the constitution less; for although in many cases the general habit may be relieved by bleeding, yet the part affected, where it can act, will in all cases require this evacuation most, and local bleeding will keep nearer these proportions; whereas taking blood from the general system is just the reverse. That local bleeding has very considerable effects on the inflamed part, is proved by the gout; for applying leeches to the part inflamed commonly relieves that part, and often almost immediately.* We find that bleeding by leeches alone will remove a tumour in the breast, having all the appearances of a scirrhus, which cannot be' considered as inflammatory; its powers, therefore, extend beyond inflammation. We find relief by bleeding in the temporal artery or jugular vein, for complaints in the"brain; or cupping and bleeding with leeches on or near the part, as applying leeches to the temples, in inflammations of the eye. I have observed that there is something similar to sympathetic affection in bleeding. I conceive that all the sympathetic powers, the universal, continued, and contiguous, may be brought into action from the local influence of bleeding. Thus, bleeding in the part inflamed, I can conceive, does more than simply empty the vessels mechanically, for that would be soon restored from the general circulation ; but it acts by continued sympathy, viz., the vessels of the part being opened, they contract for their own defence, and this is carried further along the vessels of the part; so that bleeding from the part acts in two ways, viz., mechanically, by relieving the vessels of some blood, so as to allow them to contract in proportion as the load is taken off; and also by exciting them to contraction, in order to prevent the effusion of blood. I suppose, likewise, that contiguous sympathy comes into action, for this would appear from practice and observation to be a principle in bleeding; therefore, in inflammation of contiguous parts, it is proper to bleed from the skin opposite to them, as from the skin of the abdomen in complaints ofthe liver, stomach, and bowels; and likewise from the loins in inflammatory affections of the kidneys. In affections of the lungs bleeding opposite to them is of service; but in such cases it is not clear where the inflammation is, for if in the pleura, then it does not act upon this principle, but by continued sympathy : bleeding on the scalp relieves headaches; and the relief given to the testicle by bleeding from the scrotum, in inflammation of that body, proves the principle. Where the first indication for bleeding takes place, viz., where there is violent inflammation, with strength of constitution, bleeding freely will be of singular service. The same mode of practice is also to be followed under the circumstance of strength, with respect * It is not meant here to recommend bleeding in this disease. THE ADHESIVE INFLAMMATION. 359 to the second, third, fourth, and fifth; but each will not require the same quantity to be taken under equal strength of constitution, as will be taken notice of when treating of them separately. As it seldom happens that bleeding once will be sufficient in a considerable inflammation, the first, or preceding blood taken becomes a symptom of the disease. If the coagulating lymph is long in coagulating, so that the globules have time to subside, there will be what is called a thick buff; and if its surface is considerably cupped, then future bleedings may be used with less caution ; because such appearance indicates strong powers of coagulation, which always shows strength in the solids ; but if the blood is weak in its powers of coagulation, and lies flat in the dish, then we must be cautious in our future bleedings; or if it was strong at first in its powers of coagulation, and after repeated bleedings becomes weak, then we must not pursue this further; but in some cases it is proper to pursue it to this point, for we shall sometimes find that the inflammatory symptoms shall not cease after repeated bleedings, if the strength continues; but the moment a degree of looseness is produced in the blood, that moment will the inflammatory action cease. The following case is a strong instance of this : A lady had a violent cough, tightness in respiration, loss of appetite, strong sizy blood, and the symptoms continued to the sixth bleeding; when the blood was not quite so sizy ; but the most remarkable change was its remaining flat on the surface. Upon this bleeding all the symptoms disappeared; and here, although the blood became weak in its power of coagulation, yet it did not produce irritability in the constitution, the vessels of the inflamed parts having still had power to contract. On the other hand, there may be indications for bleeding sparingly; first, when there is too much action, with weakened powers; secondly, when there is a disposition to form but little blood ; thirdly, when the part affected is far from the source of the circulation. From the above three dispositions that require bleeding sparingly, or with caution, I may observe that it will most probably be proper in all such cases to bleed from, or as near the part affected as possible, in order to have the greatest effect, with the loss of the least quantity of blood ; more so than when the constitution is strong; because the constitution in such cases should feel the loss of blood as little as possible. If from the part, leeches will answer best, because commonly little irritation follows the wound of a leech:* however, this can only be put in practice in inflammations

* However this is not always the case, for it sometimes happens that an unkindly inflammation attends the wound, though not extensive. It sometimes also happens that the lymphatic glands swell in consequence of their bite; but these so rarely occur, and are of such little consequence when they do, that they are not to be regarded. From hence it has been conceived that there is something poisonous in the bite of a leech, but I think there are no proofs of it: however, from another effect, I conceive there is a power or property applied to the wound, which hinders the irritation of contraction that naturally takes place in a wounded vessel, producing, probably, a paralysis for a time. 360 HUNTER ON THE BLOOD. not very remote from the surface. But in many cases the blood cannot be taken away from the part itself, but only from some neighbouring part, so as to affect the part inflamed : thus, we bleed in the temporal artery for inflammation of the eyes; we bleed in the jugular veins for inflammation ofthe brain; and also in the temporal artery to lessen the column of blood going to the brain, by the internal carotids. But in may situations it will probably be impossible to do this with any hopes of success, and therefore we may have recourse to the sympathetic affections before described. Too much action with small powers may often, if not always, be classed with the irritable constitution, and bleeding should then be performed with very great caution; one case out of many I shall relate as an instance of great action with debility. A gentleman had one of the most violent inflammations I ever saw in one of his eyes, attended with violent pain in his head, and the blood extremely sizy, all of which denotes great action of parts; yet the buff of the blood was so loose when coagulated that it could hardly bear its own weight, or make any resistance to the finger when pressed , and although he was bled pretty freely, yet he never found any relief from- it. This blood becoming a symptom, both of the constitution and disease, manifestly showed weak powers from its looseness, and too great action from its slowness of coagulation, which was the cause of the buff. The following case is another strong instance of great action in a weak, irritable habit. A lady had a violent inflammation at the root of the tongue, so as to form a considerable suppuration, with a pulse of 120, 125, and often 130 in a minute. Her blood was extremely sizy, yet she received but little benefit from the first bleeding, although the blood coagulated pretty firmly, which indicated strength. She was of an irritable constitution, so as to receive less benefit from bleeding than another; and when bled three times, the blood became extremely loose in its texture, which bark removed, as well as the other symptoms. Upon leaving off the bark the symptoms all recurred, and when she was bled again for the second attack, which was the fourth time, the blood, although inflammatory, had recovered a good deal of its proper firmness ; but in the second bleeding for this second attack it was less so, and in the third it was still less. Suspecting that bleeding in the present case would not produce resolution, I paid particular attention to the pulse at the time of bleeding, and found that in this last bleeding the pulse increased in its frequency even in the time of bleeding; and within a few minutes after the bleeding was over, it had increased ten strokes in the minute.* These bleedings retarded suppuration, but by producing irritability they could not effect resolution.

* This, ofthe pulse increasing upon bleeding, is not always to be set down as a sure sign of irritation being an effect; for in a sluggish pulse, arising from too much blood, the increase of stroke, and freedom given to the circulation is salutary ; but when a pulse is already quick, an increase must arise from irritation. THE ADHESIVE INFLAMMATION. 361 Where there is a disposition to form but little blood (when known), bleeding should be performed with great caution. When the inflammation is far from the source ofthe circulation the same precautions are necessary. In general it can be taken away from the part in such cases. But these are only so many facts, that require peculiar symptoms to ascertain them. The common indications of bleeding, besides inflammation, are too often very little to be relied upon, and I shall consider them no further than as it concerns inflammation, which will indeed throw light on other cases. The pulse is the great indication in inflammation, but not always to be depended upon. In inflammations that are visible a knowledge of the kind of inflammation is in some degree ascertained, as has been observed; we therefore go upon surer ground in our indications for bleeding. But all inflammations are not visible; and it is therefore necessary to have some other criterion. However, if we could ascertain the pulse peculiar to such and such appearances in visible inflammation, and that was universally the same in all such appearances, we might then suppose that we had got a true indicative criterion for our guide, and therefore apply it to invisible inflammations, so as to judge ofthe kind by the state ofthe pulse. But when we consider that the same kind of inflammation in every part of the body will not produce the same kind of pulse, but very different kinds, not according to the inflammation, but according to the nature of the parts inflamed, and those other parts also not visible, we lose at once the criterion of the pulse as a guide. When we consider also that there shall be every other sign or symptom of inflammation in some viscus, and from the symptoms the viscus shall be well ascertained, yet the pulse shall be soft and of the common frequency; and upon bleeding, in consequence of these inflammatory symptoms, the blood shall correspond exactly with all of them, except the pulse, it shall be sizy, firm, and cupped, as was the case in the lady, which has been before described, we shall be still further convinced that the pulse is a very inadequate criterion. If a pulse be hard, pretty full, and quick, bleeding appears to be the immediate remedy, for hardness rather shows strong contractile action of the vessels not in a state of inflammation, which also implies strong action of the blood, and from such a pulse a sizy blood will generally be found. But even a quick, hard pulse and sizy blood are not always to be depended upon as sure indications of bleeding being the proper method of the resolution of inflammations ; more musl be taken into the account. The kind of blood is of great consequence to be known ; for although it should prove sizy, yet if it lies squat in the basin, and is not firm in texture, and if the symptoms at the same time are very violent, bleeding must be performed very sparingly, if at all; for I suspect that under such a state of blood, if the symptoms continue, bleeding is not the proper mode of treatment. The cases of this kind which have been related are strong proofs of this. 31* 362 HUNTER ON THE BLOOD. As the pulse, abstracted from all other considerations, is not an absolute criterion to go by, and as sizy blood and a strong coagulum are after-proofs, let us see if there are any collateral circumstances that can throw some light on this subject, so as to allow us to judge a priori whether it be right to bleed or not, where the pulse does not of itself indicate it. Let us remember that in treating of inflammation of different parts I took notice of the pulse peculiar to each part, which I may now be allowed to repeat. First, I observed that an inflammation in parts not vital, or such as the stomach did not sympathize with, if there were great powers and the constitution not very irritable, the pulse was full, frequent, and hard. Secondly, that on the contrary, in inflammations of the same parts, if the constitution was weak, irritable, etc., that then the pulse was small, frequent, and hard, although perhaps not so much so as when in vital parts. Thirdly, that when the inflammation was in a vital part, such as the stomach or intestines, or such as the stomach readily sympathizes with, then the pulse was quick, small, and hard, similar to the above. Now, in the first stated positions we have some guide, for in the first of these, viz., where the pulse is strong, etc., there bleeding is most probably absolutely necessary, and the symptoms, with the state of blood joined, will determine better the future conduct; but in the second, where the pulse is small, very frequent, and hard, bleeding should be performed with great caution. Yet in inflammations of the second stated parts the constitution seems to be more irritable, giving more the signs of weakness, as if less in the power of the constitution to manage. Bleeding, restricted to two or three ounces, can do no harm by way of trial, and, as in the first case, the symptoms and blood are to determine the future repetition ; but in the third, or vital parts, viz., either the stomach or such as the stomach sympathizes with, we are yet, I am afraid, left-in the dark respecting the pulse. Perhaps, bleeding at first with caution, and judging from the blood and its effects upon the other symptoms, is the only criterion we can go by. The kind of constitution will make a material difference, whether robust or delicate. The mode of life will also make a material difference, whether [the patient is] accustomed to considerable exercise, and can bear it with ease. Constitutions so habituated will bear bleeding freely ; but those with contrary habits will not. The sex will likewise make a difference, although the mode of life will increase that difference: therefore men will bear bleeding better than women. Even age makes a material difference, the young being able to lose more blood than the old, for the vessels of the old are not able to adapt themselves so readily to the decreased quantity; it even should not be taken away so quickly, and probably the constitution may in some degree have lost the habit of making blood, since it has lost the necessity. The urine will throw-some light on the disease. If high-coloured, and not much in quantity, it may be presumed, with the other THE ADHESIVE INFLAMMATION. 363 symptoms, that bleeding will be of singular service ; but if pale and a good deal of it, although the other indications are in favour of bleeding, yet it may be necessary to do it with caution. However, bleeding should in all cases be performed with great caution, more particularly at first, and no more taken than appears to be really necessary. It should only be done to ease the constitution or the part, and rather lower it where the constitution can bear it; but if the constitution is already below or brought below a certain point, or gives the signs of it from the situation of the disease, then an irritable habit takes place, which is an increased disposition to act without the power to act with. This of itself becomes a cause ofthe continuance ofthe original disposition, and therefore will admit neither of resolution nor suppuration, but continue in a state of inflammation, which is a much worse disease than the former. Upon any other principle than those above mentioned I cannot see why bleeding should have such effects in inflammation as it sometimes has. If considered in a mechanical light, as simply lessening the quantity of blood, it cannot account for it; because the removal of any natural mechanical power can never remove a cause which neither took its rise from, nor is supported by it. However, in this light it may be of some service; because all the actions relative to the blood's motion will be performed with more ease to the solids when the quantity is well proportioned. It is probably from this connexion between the solids and fluids, that the constitution or a part is in a state of perfect quietude or health; in which [state] we find that the fluids are, and ought to be, in a large quantity ; but in a state of inflammation, or increased powers and actions, those proportions do not correspond, at least in t';e parts inflamed; and by producing the equilibrium between the two, suitable to such a state, the body becomes, so far as this one circumstance can affect it, in a state of health, and this in many cases will cast the balance in favour of health. It is not, however, sufficient to produce this effect in all inflammations. How far taking the blood from parts, peculiarly situated with respect to the parts inflamed, is more efficacious, I believe, is not yet determined, as bleeding in the left side for an inflammation in the right, upon the supposed principle of derivation, which might be classed with remote sympathy; but so far as the loss of the blood acts mechanically, viz., so far as it simply empties the vessels, it certainly can have no more effect than if taken in any other way ; nor can it affect the living principle, either universally or locally, more in this mode than in any other. But how far it can affect the sympathizing principle I do not know. Bleeding is often performed from no constitutional indication, but only as a preventive arising from experience, such as in consequence of considerable accidents, as blows on the head, fractured bones, &c; but this is not to the present purpose. 364 HUNTER ON THE BLOOD. § 11. The Use of Medicines internally, and of Local Applications in Inflammation.

Everything given to the body, or applied to the part inflamed, that can abate inflammation, or its effects in the constitution, may be called medicine. Such, therefore, divide themselves into constitutional and local. The first will be internal, the second external; but whichsoever way they are applied, they that tend to lessen inflammation have their effects local: for mercury, although given internally for a venereal ulcer in the throat, yet acts locally on the disease; but those that tend to remove constitutional affections have their effects constitutional. The internal medicines generally ordered for the resolution of inflammation are such as tend to have similar eflects to that which is produced by bleeding, namely, lowering the constitution or the action ofthe parts, and this has usually been performed principally by purges; and the medicines that were given to remove or lessen the effects of inflammation on the constitution, have been such as generally tend to lessen fever, or the effects that the inflammation has upon the constitution. Purges were generally given in cases of inflammation (probably at first from the idea of humours to be discharged), and such practice will answer best where bleeding succeeds, because it will lower the body to a more natural standard, and of course the inflamed part, as a part of that constitution; but here the same cautions are necessary that were given upon bleeding, because nothing debilitates so much as purging when carried beyond a certain point. One purging stool shall even kill, where the constitution is very much reduced, as in many dropsies; therefore, keeping the body simply open is all that should be done. However, although purging lowers considerably, yet its effect is not so permanent as that of bleeding. It rather lowers action, without diminishing strength ; for if a person was to feel the loss of blood equal to a purge, that sensation would be more lasting. Many constitutions rather acquire strength upon being gently purged, particularly such as have been living above par. But such strength as is acquired by putting the body in good order, I should suppose, is not inimical to inflammation. In irritable habits, where the inflammation becomes more diffused, greater caution is necessary with regard to purging as well as bleeding; for I observed on the subject of bleeding, that in such constitutions no more blood should be taken than would relieve the constitution, as it were mechanically, but not such a quantity as to have a tendency towards lowering or weakening that constitution, for in such cases the action is greater than the strength ; and whenever the disposition between these two, is of this kind, we cannot expect anything salutary from this mode of treatment, and therefore should not increase it. In such cases, the very reverse of the former THE ADHESIVE INFLAMMATION. 365 method should often be practised : whatever has a tendency to raise the constitution above irritability should be given, such as bark, &c. The object of this last practice consists in bringing the strength of the constitution and part as near upon a par with the action as possible, by which means a kindly resolution or suppuration may take place, according as the parts inflamed are capable of acting. Medicines which have the power of producing sickness lessen the action, and even the general powers of life, for a time, in consequence of every part of the body sympathizing with the stomach; and their effects are pretty quick. Sickness lowers the pulse, makes the smaller vessels contract, and rather disposes the skin for perspiration, but not of the active or warm kind; but I believe it should proceed no further than sickness, for the act of vomiting is rather a counteraction to that effect, and produces its effects from another cause, and of course of another kind, which I believe rather rouse. It is probably an action arising from the feel of weakness, and intended to relieve the person from that weakness. It is similar to the hot fit of an ague, a counteraction to the cold one. There are few so weak but they will bear vomiting, but they cannot bear sickness long. If we had medicines which, when given internally, could be taken into the constitution, and were endowed with a power of making the vessels contract, such I apprehend would be proper medicines. Bark has certainly this property, and is of singular service I believe in every inflammation attended with weakness, and therefore, I conceive, should be oftener given than is commonly done; but it is supposed to give strength, which would not accord with inflammations attended with too much strength and considerable irritation. Preparations of lead, given in very small doses, might be given with success in cases attended with great strength. Applications to the body to cure or resolve inflammations are, with regard to their mode of application, of two kinds: one is applied to the part inflamed, the other to some distant part. The first may be called local, or absolute respecting the part itself; the second relative. But even the first may be considered as having a relative effect in one of its modes of action, viz., that called repulsion, from which local applications have by some been objected to, and it is principally local applications that can repel, although not literally. The first, or absolute effects of medicine, may be divided into two kinds, viz.: one, the simple cure of the part, the other producing an irritation of another kind in the part; both, however, act locally, and their ultimate effect is local. Local applications to a part, where those applications possess really the powers of resolution, must be much more efficacious than any of the other modes of resolution. For instance, mercury has much greater powers when applied immediately to the venereal complaint, than when applied to the nearest surface; where, however, we have not medicines that can resolve inflammation by application, then of course the other 366 HUNTER ON THE BLOOD.

method is the most efficacious; but whether we have external or local applications which have really a tendency to lessen the inflammatory disposition is not well ascertained. I doubt our being in possession of many that can remove the immediate cause. Such would of course remove the action, or, if not wholly, would at least lessen it, and allow the inflammation to go off. But most of our powers in this way appear to be ofthe soothing kind, which therefore lessen the action (although the cause may still exist), and hence the effects are also lessened. This either produces a termination of the inflammation; or it is protracted, the cause lessens, and the inflammation wears itself out. As inflammation has too much action, which action gives the idea of strength, such applications as weaken have been recommended, and cold is one of them. Cold, according to its degrees, produces two very different eflects, one is the exciting of action without lessening the powers, the other is absolutely debilitating, while at the same time it excites action, if carried too far. In the first it becomes like suitable exercise to the vascular system, as bodily exercise is to the muscles, increasing strength; but when carried or continued beyond this point it lessens the powers, and becomes a weakener, calling up the action of resistance after the powers are lessened; therefore cold should not be indiscriminately used, and should be well proportioned to the powers. Cold produces the action of contraction in the vessels, which is an action of weakness. A degree of cold suddenly applied, which hardly produces more than the sense of cold, excites action after the immediate effect is over, which is the action of dilatation, and which is the effect ofthe cold bath when it agrees; and as cold produces weakness in proportion to its degree, its application should not be carried too far, for then it produces a much worse disease, viz., irritability, or over-action in respect to the strength of the parts, and then indolence too often commences. Cold might be supposed to act on an inflamed part similarly to its action on a frozen part, restraining action, keeping it within the strength of the part in the one case, so as not to allow death to take place from over-action, and in the other keeping it within bounds.* Lead is also supposed to have considerable effects in this way; but I believe much more is ascribed to it than it deserves. The property of lead appears to be that of lessening the powers and not the action; it therefore should never be used but when the powers

* As cold can be applied upon two very different principles, it is necessary to mention which is here meant. When cold is applied either within the powers of resistance of the part to excite heat, or only for so short a time as to give the stimulus of cold, then a reaction takes place, and warmth is the consequence; but if cold is applied beyond the powers of resistance, then a contraction of the vessels takes place, and that contraction is in some degree permanent. But this must be done with caution ; for if continued too long it will produce debility, and action will be excited which will be irritable. In the present case the application of cold should only be sufficient to excite the contraction of the vessels, and that not continued too long, for reasons above assigned. THE ADHESIVE INFLAMMATION. 367 are too strong, and acting with too much violence. However, lead certainly has the power of producing the contraction of the vessels; and therefore, where there is great strength, lead is certainly a powerful application. Applications which can weaken should never be applied to an irritable inflammation, especially if the irritability arises from weakness. I am certain I have seen lead increase such inflammations, particularly in many inflammations of the eyes and eyelids, and I believe it is a bad application in all scrofulous cases; in such cases the parts should be strengthened without producing action. Warmth, more especially when joined with moisture, called fomentation, is commonly had recourse to, but I am certain that warmth, when as much as the sensitive principle can bear, excites action; but whether it is the action of inflammation, or the action of the contraction ofthe vessels, I cannot determine. We see that in many cases they cannot bear it, and therefore it might be supposed to increase the action of dilatation, and do hurt; but if that pain arises from the contraction of the inflamed vessels, then it is doing good; but this I doubt, because I rather conceive the action of contraction would give ease. Acids have certainly a sedative power, as also alcohol, and 1 believe manv of the neutral salts. I believe it is not known that we have the power of adding strength to a part bv local applications : that in general, I believe, must arise from the'constitution; for although we have the power of giving action, yet this does not imply strength. Many local applications are recommended to us, respecting many of which I have my doubts. The mode of cure by an irritation different from the disease appears to increase the disease; but by destroying the first mode of action it produces another disease, viz., according to the mode of irritation of the application, and which more easily admits of a cure than the first. I believe, however, that this takes place principally in specific diseases, and not so readily in common inflammation ; for a common inflammation most probably would be increased by it. I have known specific inflammations much more easily cured by their specific medicine than the common inflammation of the same constitution, viz., I have seen a gonorrhoea and a chancre cured much more easily in some constitutions than an inflammation from an accident, and oftener than once or twice in the same person. However, this mode will not do in all specific diseases, for the scrofula will not change its nature by it, nor will the irritable, although specific. The venereal gonorrhoea (if parts are very irritable) is an instance of this, for irritating injections increase it; still we have many cutaneous inflammations cured in this way, for a pretty strong solution of corrosive sublimate will remove an inflammation ofthe skin. The unguentum citrinum, mixed with any common ointment, cures many inflammations of the eyelids; yet I believe that artificial irritations are similar to one another, and I 368 HUNTER ON THE BLOOD. do not know if there be any difference between them, although I can conceive one may agree better with some constitutions than others. However, these local or immediate applications can only be such as come in contact with the disease, which always must be some exposed surface, as when the skin ofthe eyelids, tonsils, c^c, are inflamed; but even there some part must be affected by continued sympathy if they produce a cure, as the inflammation generally goes beyond the surface of immediate contact. That inflammation which admits of repulsion, although by local means, might be considered here ; but, from its effects and connexion with the constitution, it comes in more properly with the several relations under which I shall consider it.*

* [The three great means of reducing inflammation must ever consist in the use of blood-letting, purging, and the adoption of an antiphlogistic regimen. In regard to which it may be observed, that the first should be had recourse to early in the disease, and be carried to such an extent as to produce an evident abatement ofthe symptoms : the second should be so contrived as to insure a regular and continued action ofthe bowels during the whole course of the disease; and the third should not be relaxed in until all the symptoms of active inflammation have disappeared. To these all other measures must be regarded as subsidiary in cases of extensive inflammation affecting vital parts, although in cases of less severity it may happen that the auxiliary measures, or some particular methods of treatment adapted to the peculiar circumstances of the case, may claim the principal attention. Among the auxiliary measures brought forward since the author's death, two or three may here be briefly adverted to, for the purpose chiefly of pointing them out to the student's attention rather than of forming any exact appreciation of their value. 1. The efficacy of mercury in controlling the inflammatory acthn is in no instance so well exemplified as in inflammation ofthe iris; for, as the parts are here open to our view, we obtain demonstrative evidence of its power, not only in checking the morbid action but in occasioning the absorption of adventitious deposits. The efficacy of mercury, however, is limited to particular cases. It is greatest in iritis, laryngitis, hepatitis, and inflammation ofthe testicle; less in the mucous and serous membranes and trre parenchymatous viscera; and still less in the common cellular membrane and other tissues. Its success is most marked in dispelling the remaining inflammation after the acute symptoms have been subdued, and therefore it should not be administered until a proper measure of blood-letting and purging have been previously adopted. Its administration should also be continuous, so as to keep the constitution under its influence, and if it excites either local or constitutional irritation its use should be immediately discontinued. 2. It has been proposed to accomplish all the beneficial objects of depletion by the administration of sedative medicines, such as digitalis and prussic acid, which by acting directly on the heart reduced the strength and frequency ofthe pulse; but experience has not confirmed these pretensions, nor was it indeed to he expected, since the same or very nearly the same effects are produced by many forms of visceral inflammation, which proceed nevertheless to a fatal termination, and that too with the greater certainty in proportion as these symptoms continue: neither have emetics, except in a few instances, any decided effect in checking inflammatory action, although the depression which they produce is very nearly analogous to that produced by the above-mentioned medicines. Excitability and stimulants are correlative terms, but very different effects are produced by the temporary reduction of the former and the actual reduction of the latter: by the latter the disease is removed, but by the former it is merely masked. 3. The effect of antimonial medicines is to lower the pulse and to restore the actions ofthe skin; but it has been proposed by Tommasini and the Italian phy- THE ADHESIVE INFLAMMATION. 369 § 12. General Observations on Repulsion, Sympathy, Derivation, Revulsion, and Translation. These terms are meant to be expressive of a change in the situation of diseased actions in the body, and they are so named according to the immediate cause, for any one disease may admit of any of these modes equally; that is, a disease which admits of being repelled may admit of being cured by sympathy, which probably includes derivation, repulsion, and translation. That such a principle or principles exist is, I think, evident, but the precise mode of action is, 1 believe, not known; that is, it is not known what part ofthe body more readily accepts ofthe action of another; if there are such parts, they might be called correspondent parts, whether the action changes its place from repulsion, sympathy, derivation, or translation. In derivation and repulsion, whether one mode of irritation is better than another, to invite or divert the action, and whether parts of a peculiar action do not require a peculiar irritation to divert them ; to all this we are likewise totally strangers. It is not to my present purpose to go into the different effects of this principle, although I must own it might be as useful a part of the healing art as any ; and even more, for it is probably the least known, as being the least intelligible, and therefore the more use may be derived from its investigation. The operations denominated by these terms, so far as they exist, appear all to belong to the same principle in the animal ceconomy, for they all consist either in a change of the situation of a disease or its action;—a change ofthe situation, as in the gout; a change of the action, as a swelling of the testicles in the stopping of a

sicians to administer the antirnonium tartarizatum in large doses of from ten to sixty or even ninety grains, two or three times a day, which in cases where it is likely to prove beneficial are said not to produce sickness and purging, except after the first dose, but to act specifically on the extreme vessels so as to correct the morbid action. The plan, however, has been tried in this country without success, and in those cases where it has appeared to be of service, the good effects have seemed to arise either from the evacuation of the stomach in the first instance by vomiting, or by keeping up a gentle action ofthe bowels by purging, or else by subduing to a certain extent the heart's action; effects which may clearly be attained with more safety and ease by other means. 4. The last measure which I shall mention is the adoption of incisions, for which we are chiefly indebted to Mr. Copland Hutchinson and Mr. Lawrence. This method is principally serviceable in erysipelas, or diffuse inflammation of the cellular membrane. In the former case it relieves the tension of the skin and effectually unloads the vessels, while in the latter it gives exit to sloughs or putrid matter, and excites the parts to a healthy action. The length and^epth ofthe incisions may vary from mere superficial incisions of a half inch in length to deep incisures extending through the whole adipose structure and reaching to a foot in extent. This plan is often very successful where the patient has a robust constitution, and has besides the courage to submit to so severe a method of procedure; but in other cases, especially if the incisions are of o-reat extent the loss of blood may prove fatal, or at least so weaken the patient as considerably to protract the convalescence.] 32 370 HUNTER ON THE BLOOD. gonorrhoea. This last is not properly a change of the situation of the disease, but only of the general inflammatory action without the specific action; these principles can only produce a change in the seat of action, not in any of the consequences of disease; they have in some instances a connexion with the natural operations of the body, as it were, interfering with them ; and when that is the case they in general must produce disease of some kind. Thus the stopping of the menses, which is a local natural action arising from the constitution, may be effected by local applications called repelling, by a derangement ofthe constitution, and byimany consequences which depend on a deranged constitution simply ; or it may be drawn off'by a derangement of the constitution, which is a kind of derivation or revulsion. We find that local applications derange also other parts, which have no visible effect upon the part of application as the above, nor any visible connexion with the parts which assume the action. Thus cold, especially if wet be applied to the feet, will bring on complaints in the stomach and bowels by sympathy; and the same mode of application of cold, if local, will produce a local complaint, as cold air blowing on a part will bring on rheumatism. These changes were all supposed formerly to be of more consequence than I apprehend they really are, for they are only the change of situation of disease. They were introduced into the ceconomy of disease from the idea of humours. Repellents were such applications as drove the humours out of a part, which would fall on some other; sympathy consisted in another part taking them up; derivation was a drawing off, or inviting the humours: revulsion was the same; and translation was the moving of humours from one part to another. Thus we have those different terms applied to that connexion of parts, by which one part being affected, some other is affected or relieved ; or, as in translation, .some other part takes up the disease as it were voluntarily, as is often the case in the gout. All of these produce one of the symptoms of a disease, viz., sensation and inflammation, but I believe seldom if ever real diseased structures. This agrees with what was formerly observed, that local inflammations depending on the constitution seldom if ever suppurate.^ I believe that these powers have greater effects in diseases

* [The present state of our knowledge does not enable us to give a complete account of these varieties of action, viz., repulsion, derivation, and metastasis; but it seems probable that they are all ultimately to be referred to the same general principle. The primary laws which appear to govern these phenomena are, first, the tendency which there is in all animal bodies to preserve an equilibrium, in consequence of which it happens that when any one part of the frame is unusually excited, a corresponding diminution takes place in the functions of other parts, so that in disease, the lesser disease gives way to the greater; and secondly, the affinities of structure and function, and the mutual relations which subsist between different parts, in a state of health ; for it accords with experience, and at the same time is most agreeable to reason, to find that those parts which have a similarity of structure, and consequently of vital endowments, should be affected more readily by the causes of disease than parts of a different THE ADHESIVE INFLAMMATION. 371 depending on or producing action and sensation, which are called nervous, than on those producing an alteration in the structure of parts. Thus we have the cramp in the leg cured by a gentle irritation round the lower part of the thigh, such as a garter, which may be said to arise from derivation or sympathy; and I have known, in a nervous girl, a pain in one arm cured by rubbing the other. These cures by derivation, repulsion, translation, etc., do not deserve that name, although the patients are cured of the original disease, as in many cases there is as large a quantity somewhere else in the body uncured; for example, in those cases where the cure is from some local inflammation being produced, and perhaps more violent than the first; but in other cases, where the cure arises only from an action in a part without a diseased alteration of structure, then the cure in such cases is performed without any other disease having been produced, such as sickness or vomiting during a disease of the testicles. I have already observed that local applications were principally supposed to repel, by the first or second mode of action; yet internal medicines having a specific, or what might be called a local action, although given internally, may repel by stopping the diseased action in the part which it chiefly affects, such as mercury falling on the mouth, might repel a disease from the mouth. Hemlock might do the same with regard to the head, or turpentine with regard to the urethra. In the last we often find by taking balsams, that by stopping the discharge a swelling of the testicles comes on, or an irritable bladder. As repulsion in this way is not so evident, it is less noticed. The uncertainty in the power of medicines respecting repulsion, has led surgeons into more errors than any other principle in the animal ceconomy, with regard to diseases. It has prevented their acting in many cases where they might have done it with safety and effect. A stronger instance cannot be given than in that species of the venereal disease called a gonorrhoea, which they did not venture to cure by local applications, for fear of driving it into the constitution, and producing a pox ; but they did not consider that a gonorrhoea did not arise from the constitution, but may be said to arise from accident, or at least is entirely local, and therefore no repulsion could take place. The idea of repelling was first introduced when local diseases were supposed to arise from a deposit or derivation of humours to a part, and is still retained by those who cannot or will not allow themselves to think better; yet still the term might be applied to diseased action; for the

construction; and also, that parts associated in health should likewise become associated in disease. The former law explains in some measure the general principle of metastasis; the latter, the particular cause which determines the disease to any one organ rather than to another. The author has expressed his opinion, that in these affections the inflammation, but not the disease, is translated (p. 311) ; but this is a refined distinction, in opposition to the general fact, that the liability to metastasis is almost exclusively confined to specific diseases.] 372 HUNTER ON THE BLOOD. removal of many diseased actions from a part which fall on some other part is certainly the repelling of that diseased action ; but since it is not subdued, but only driven from the part, as is often the case with the gout, no cure is performed by this means. Both or either ofthe two local methods of removing disease, just now mentioned, viz., whether by simply curing the disease, or by destroying the diseased action, in consequence of exciting an action of another kind, may produce the effect called repulsion; but the former, I believe, can only take place in inflammations arising from the constitution, and which being prevented from settling in this part, return upon the constitution again, and often fall upon some other part, viz., one next in order of susceptibility for such inflammation, as is often the case in the gout, and in many other diseases besides inflammation, as in many nervous complaints. St. Vitus's dance is a remarkable instance of it; but in this case it is not to be considered as a cure of the disease, but only as a suspension of its action in this part. I could conceive it possible that the second mode of local cure, which is by producing an irritation of another kind, might not repel, although it cured the first or local complaint, because there is in such modes of cure still a larger quantity of inflammation in the part than was produced by the disease (although of another kind); but as the idea of repelling is to have a disease somewhere, although not in the same place, keeping it in the present situation may be as proper, if not more so, than in any other it might go to. But if, on the other hand, the constitution requires to have a local complaint arising from itself, which, as it were, is drawing off or relieving this constitutional disposition, then curing the one already formed, by producing another in the same part, can be of no service ; for if the artificial disease is not ofthe same nature with the constitutional one (which it cannot be if it destroys it), then it cannot act. as a substitute for it. We may observe, that by producing an irritation of another kind in the gout, we may destroy the gouty inflammation in the part, but cannot always clear the constitution of it; there is therefore no benefit arising from such practice in these cases. The repelling powers which act from applications being made to the parts immediately affected, or by the change of one disease into another, become the most difficult "of any to be ascertained; because it must be very difficult to say what will merely repel and what will completely cure, or perfectly change the disease. Repulsion is certainly to be considered as a cure of the part, whatever may be the consequence; and a change in the disease is certainly a cure ofthe first, although a disease may still exist in the part. That an artificial irritation made on one part does not (always at least) cure or remove a diseased irritation of a specific nature in another part, is, I think, evident in many cases, even although that specific [disease] should be an affection of the constitution. This at least was evident in a case of the gout, for when the gout was in THE ADHESIVE INFLAMMATION. 373 some of the vital parts, and sinapisms were applied to the feet, they did not relieve those vital parts, although the inflammation in consequence of the sinapisms was considerable ; but this inflammation brought on the gout in the feet, and as soon as this happened the vital parts were relieved, from which it would appear that a specific. irritation required a specific derivator. It may be supposed that the inflammation, in consequence of the sinapisms, brought on or produced such a derangement in the feet as made them more susceptible ofthe gout, or that the inflammation became an immediate cause of the action of the gout taking place there. It is plain, too, that where there is a gouty disposition, or a gouty action in the constitution, a derangement in a part may bring it on, for in the above person, who had still those internal spasms recurring upon the least exercise or anxiety of mind, but was in all other respects, and at all other times, well, by applying sinapisms a second time to his feet, till a considerable cutaneous inflammation came on, the gout attacked the ball of the great toe of the right foot, and the last joint of the great toe of the left, which lasted about two days. This attack of gout, however, did not relieve him of the remaining spasms, as the first did, and therefore was to be considered an additional gouty action. This could certainly not have taken place if the constitution had not been gouty. In diseases where we have no specific application capable of acting immediately, the advantages gained by derivation, revulsion, or sympathy are much greater in many cases than by the effects of anylocal application at present known; and the medicines which are capable of producing this effect are often such as would either have no* effect if applied to the diseased part, or would increase it. This arises from the dissimilar actions ofthe two parts; that is, the diseased actions of the one being similarf to, or producing the actions of recovery in the other; nor is it difficult to conceive why it should be so; for since the medicines are not specifics, but only invite or remove the disease by that connexion which the living powers ofthe one part have with those of another, it is reasonable to suppose that this principle of action between the parts must be much stronger than the effects of many medicines which have only a tendency to cure, or perhaps no tendency that way at all. Thus we find that vomits will often cure inflammation of the testicles when all soothing applications prove ineffectual, and when the same emetic could not have the least effect on the part itself were it applied to it. Thus we also find that a caustic behind the ear will relieve inflammations of the eyes or eyelids, when every application to the parts affected has proved ineffectual, and when this caustic, if applied to the parts themselves only as a stimulant, would increase the disease. Sympathy, perhaps, (except the continued,) includes the mode of

* ["an effect" in the original text.] t [The sense of the passage seems to require that we should read dissimilar.] 32* 374 HUISTER ON THE BLOOD. action in all of those which I have called relatives, viz. repulsion, derivation, revulsion,and translation ; at least it is probably the same principle in the whole. What I would call a cure by sympathy, is producing a curative action in a sound part, that the diseased may .take on the same mode of action from sympathy that it would take on if the curative was applied to it; so that sympathy might even be supposed to repel in cases which would admit of repelling, and fall on some other part, although not the part necessarily where the application was made. The difference between derivation or repulsion, and sympathy, consists in derivation producing a disease in a sound part to cure a disease in another part, as was observed ; while sympathy is applying the cure to a sound part to cure the diseased; but in many cases it will be very difficult to distinguish the one from the other. Sympathy is very universal, or more general than any [of the] others; for there are few local diseases that do not extend beyond the surface of contact, which produces continued sympathy; and also, there are few parts that have not some connexion with some other part, which gives us remote sympathy. It may be recollected, that when sympathy was treated of, it was divided into continued, contiguous, remote, similar, and dissimilar. The cure by continued sympathy is that application which we have reason to suppose would cure if applied to the part itself, such as applying mercury to the skin over a venereal node. The node is cured by its sympathizing with the mercurial irritation of the skin; and the action ofthe sympathizer here is similar to the action of the part of application. Remote sympathy is seldom if ever produced by a similarity of action in similar parts, but most probably cures by dissimilar modes of action in the two parts, and therefore might be called dissimilar sympathy, viz., by stimulating the part of application in such a way that the sympathizer shall act in the same way as if the real application of cure was made to it, and yet the mode of action of the part of application shall not be at all similar to the sympathizer. I can even suppose a local disease cured by sympathy, and by that medicine which would increase it, if applied immediately to it. Let us suppose, for example, any diseased mode of action, and that this mode could be increased by some irritating medicine, if applied [directly] to it; but apply this irritator to some other part which this diseased part sympathizes with, and [suppose] that the sympathetic act in the diseased part shall be the same as if its [proper] curative medicine was applied to it,—similar [in short] to what would have taken place if its specific irritator was applied,—then, in such a case the medicine would cure by sympathy, although it would increase the disease if applied locally, or have no effect at all. The contiguous sympathy is where it would appear to act from the approximation of dissimilar parts, and therefore is not continued sympathy; neither can it be called remote sympathy, as there appears to be no specific connexion, but to arise entirely from con- THE ADHESIVE INFLAMMATION. 375 tiguity or approximation of parts. Of this kind are blisters on the head, curing headache; on the chest, curing pains in the chest; to the pit ofthe stomach, to cure irritations there ; to the belly, to cure complaints of the bowels. The applications which act by contiguous sympathy are only those which can be applied to the nearest surface to that which is inflamed, when the inflamed part beyond this surface becomes affected in some degree similar to the part of application, such as the applications to the eyelids, when the inflammation is in the eye ; to the scrotum, when it is in the testicle : to the abdomen, when some of the bowels are inflamed ; to the thorax, in inflammations of the lungs, etc. These may be either of the specific, stimulating, or soothing kinds,—something which affects the parts in such a manner as that a remote diseased action ceases. It may be specific, as opium applied to the pit of the stomach curing an irritation of that viscus ; stimulating, as blisters to cure inflammation in the subjacent viscera, as has been mentioned; soothing, as fomentations to the abdomen to relieve complaints in the bowels. Derivation means a cessation of action in one part, in consequence of an action having taken place in another; and when this is a cessation of a diseased action, then a cure of that action in the original part may be said to be performed; this cure was brought into use from the idea of humours, that is, the drawing off of the humours from the seat where they had taken possession; but I believe much more has been ascribed to it than it deserves. How far it really takes place I have not been able fully to ascertain in all its parts: that is, how far the real disease is invited, and accepts of the invitation; but I have already observed, that there is such a principle of disease in the animal ceconomy, although we must see from derivation that the same quantity, or perhaps more irritation, is retained in the constitution ; yet the artificial irritation produced being either such as more readily admits of a cure than the disease in the part, or being in parts which are not so essential to life, an advantage by this means is gained ; thus, burning the ear is practised as a cure for the toothache, and the part which is burnt more readily admits of a cure than the tooth. We also find that blisters often cure or remove deep-seated pains, such as headache, and relieve the bladder when applied to the perinaeum. Blisters and caustics behind the ear cure also inflammations of the eye. Less may be said on revulsion, since we have explained derivation. To draw off a disease always implies safe ground, and can be applied with safety in any disease; revulsion can best be applied when the disease attacks essential parts, where the application cannot be so near as to imply derivation. Thus we find that vomits will cure an inflammation of the testicles, white swellings, and even venereal buboes; and sinapisms applied to the feet relieve the head. Translation differs from derivation, revulsion, and repulsion, only as it proceeds from a natural or spontaneous cause, whereas these 376 HUNTER ON THE BLOOD. proceed from an artificial, accidental, or external cause, and the common principle of them all seems to be sympathy ; for if not an act of its own [i. e., of the disease itself], then it must be either repelled, derived, or from sympathy. Very strange instances of translation are given us; it has been supposed that pus already formed has been translated to another part of the body, deposited there in form of an abscess, and then discharged. This is an operation absolutely impossible.* Matter absorbed may be carried off by some of the secretions, such as that by the kidneys, which have a power of removing more than they secrete; but the deposition of pus is the same with its formation. Both revulsion and repulsion may be reckoned a species of translation. The gout moving of its own accord from the stomach to the foot, or from one foot to the other, may be reckoned a translation of the gout.

§ 13. Of the different forms in which Medicines are applied, and the subsiding of Inflammation.

Fomentations or steams, washes, and poultices are the common applications to a part in the state of inflammation. The first and last are commonly applied to inflammation arising from external violence, and proceeding to suppuration ; the second, commonly to internal surfaces, as the mouth, nose, urethra, vagina, rectum, etc. The action of the two first is but of very short duration. Fomentations and steams are fluid bodies raised into vapour: they may be either simple or compound; simple, as steam, or vapour of water; compound, as steam of water impregnated with medicines. This mode of applying heat and moisture appears, from experience, to be more efficacious than when these are applied in the form of a fluid; it often gives ease at the time of the application, while at other times it gives great pain; but if it does give ease, the symptoms generally return between the times of applying it, and with nearly the same violence. How far the application of a medicine for fifteen minutes out of twenty-four hours can do good, I am not certain; we find, however, that the application of a vapour of a specific medicine, though but for a few minutes in the day, will have very considerable effects : fumigations with cinnabar may serve as an instance.^ The fomentations are commonly composed of the decoction of herbs; sometimes of the marsh-mallows, but oftener of the decoction of herbs possessing essential oil, which I believe are the best; because I suppose that whatever will excite contraction of the vessels, will in some degree counteract the dilating principle. Vinegar as well as spirits are put into them,

* [This opinion is nevertheless entertained by several justly celebrated physiologists of the present day. See Principles of Surgery, p. 137, note, and Andral, Anat. Pathol., i. 405.] f [But in this instance the mercury is rapidly absorbed into the system.] THE ADHESIVE INFLAMMATION. 377 but how far they stimulate to contraction I do not know, but rather believe they remove irritation, which must lessen the inflammatory action. Washes are in general fluid applications, and are more commonly applied to inflammations of internal surfaces than of the common integuments: there are washes to the eye, called collyria; washes to the mouth and throat, called gargles ; washes to the urethra, called injections; and to the rectum, called clysters; but I am fearful we are not yet acquainted with the true specific virtues of these washes, at least there is something very vague in their application. There are, for instance, astringeut washes for the inflammation of the eye, such as white and blue vitriol, alum, etc.; stimulating warm gargles for inflammations of the throat, such as mustard, red port, claret, with vinegar and honey; but to moderate or resolve external inflammations, they do not apply substances with any such properties.* How would it appear to surgeons in general, if any one made use of the same applications to an inflammation in any other part; yet I do not know if there is any difference between an inflammation ofthe eye or throat, and one in any other part, if the inflammations are of the same kind: mercury cures a venereal inflammation, either of the eye or throat, as easily as a venereal inflammation anywhere else, because it is an inflammation ofthe same kind. These applications, like fomentations, are of short duration, for there is no possibility of applying these powers constantly, except in the form of a poultice, whose operation is somewhat similar; and, indeed, they are only substitutes for a poultice, where that mode of application cannot be made use of, as I observed with respect to internal surfaces. Poultices are constant applications, and like fomentations, may be of two kinds, either simply warm and wet, or medicated. The greatest effect that a poultice can produce must be immediate, but its power will extend beyond the surface of contact, although only in a secondary degree. To the common inflammation the simplest poultices are supposed to be the best, and produce their effect, I believe, only by keeping the parts easier under the complaint; but I am of opinion that such do not affect the inflammation any other way. A common poultice is, perhaps, one of the best applications when we mean to do nothing but to allow nature to perform the cure with as much ease to herself as possible. Poultices may be medicated, so as to be adapted to the kind of inflammation, as with the solution of lead,

* [The reason of this is sufficiently obvious, for if the external integuments of the body are deprived of their defence of cuticle, and assimilated therefore in conditions to the mucous membranes, the same effects are produced in them ; which effects it may be observed are more or less of a permanent nature. The consequences which ensue from the application of various metallic or saline solutions to the web of a frog's foot, leave no doubt as to the fact ofthe imbibition of foreign substances by the lining cuticle, and of their influence upon the subjacent vessels.] 378 HUNTER ON THE BLOOD. opium, mercury, etc.; in short, they may be compounded with any kind of medicine. Whatever the disposition is which produces inflammation, and whatever the actions are which produce the effects, that disposition, under certain circumstances, viz., when it arises either from the constitution or the parts, can be removed, and of course the actions excited by it. The disposition for inflammation shall have taken place, and the vessels which are the active parts shall have dilated, and allowed more blood to enter them, so that the part shall look red; but no hardness or fulness shall be observed, and the whole shall subside before adhesions have been formed; or if inflammation has gone so far as to produce swelling, which is the adhesive stage ofthe disease, it by certain methods can be frequently so assuaged as to prevent suppuration taking place, and then the parts will fall back into their natural state, which is called resolution, some adhesions being perhaps the only remaining consequences of the inflammation. The same methods are likewise often used with considerable success in lessening inflammation arising from violence, so as to prevent suppuration entirely ; but in many of these cases they are not sufficient, and in those where it cannot be prevented, yet it may be lessened by the same means. As the first symptom of inflammation is commonly pain, so is the first symptom of resolution a cessation of that pain, as well as one of the symptoms of suppuration, which is a species of resolution. I have known the cessation of pain so quick as to appear like a charm, although no other visible alteration had taken place, the swelling and colour being the same. Why inflammation of any kind should cease after it has once begun is very difficult to explain, or even to form an idea of, since as yet we have no mode of counteracting the first cause, or irritation. It may he supposed to arise from the principle, of parts adapting themselves in time to their present situation, which I call custom ; and that, therefore, in order to keep up the inflammation, it would be necessary for the cause to increase in proportion as the parts get reconciled to their present circumstances. But, allowing this to be the cause, it will not account for their returning back to their natural or original state, when this increase of irritation ceases, and only the last or original irritation remains ; for upon this principle they only grow more easy under their present state, or perhaps, which is worse, acquire a habit of it, which may be the cause of many indolent specific diseases. If we suppose the removal of the original cause to be sufficient to stop the progress of inflammation, and when this is stopped that the parts cannot easily remain in the same inflamed state, but by their own efforts begin to restore themselves to health, (which we can easily conceive to be the case in specific diseases, especially those arising from poisons of such kinds as are capable of a termination, as the small-pox, or where a cure can be administered for THE ADHESIVE INFLAMMATION. 379 the effects of the poison, as in the lues venerea,) then we must conclude that the inflamed state is an uneasy state,—a force upon the organs which suffer it, like the bending of a spring, which is always endeavouring to restore itself, and the moment that the power is removed returns back to its natural state again; or it may be like the mind, forgetful of injuries.

§ 14. Ofthe Use ofthe Adhesive Inflammation.

This inflammation may be said in all cases to arise from a state of parts in which they cannot remain, and therefore an irritation of imperfection takes place. It may be looked upon as the effect of wise counsels, the constitution being so formed as to take spontaneously all the precautions necessary for its defence; for in most cases we shall evidently see that it answers wise purposes. Its utility may be said to be both local and constitutional, but certainly most so with regard to the first. Its utility is most evident when it arises from a disease in a part, whether this proceeds from the constitution or otherwise; and when it does, it must be considered as arising from a state in which that part cannot exist,—as in exposure,—and therefore is the first step towards a cure. It is often of service in those cases which arise from violence, although not necessarily so, the injured parts not being always under the necessity of having recourse to it, as was shown in treating of union by the first intention. When the adhesive inflammation arises from the constitution, it may depend on some disease of that constitution; and if so, it may be conceived to be of use to it, especially if it should be supposed to be the termination of a universal irritation in a local one, by that means relieving the constitution of the former, as in the gout; but when it is only the simple adhesive inflammation that takes place, I am rather apt to think that it is more a part of the disease than a termination of it, or an act of the constitution. The adhesive inflammation serves as a check to the suppurative by making parts, which otherwise must infallibly fall into that state, previously unite, in order to prevent its access, as was described when speaking of the adhesive inflammation being limited; and where it cannot produce this effect, so as altogether to hinder the suppurative inflammation itself from taking place, it becomes in most cases a check upon the extent of it. This we see evidently to be the case in large cavities, as in the tunica vaginalis after the operation for the hydrocele; for after the water has made its escape, parts of the collapsed sac frequently unite to other parts of the same sac by this inflammation, and thereby preclude the suppurative from extending beyond these adhesions, which so far prevents the intention of the surgeon from having its full effect; and often, on the other hand, the adhesive state of the inflammation takes place universally in this bag, in consequence of the palliative cure, which produces the radical cure, and prevents a relapse. In the hernia 380 HUNTER ON THE BLOOD. it performs a cure by uniting the two sides of the sac together, by means of slight pressure, so that we should understand perfectly its mode of action, where it can prevent a cure, and where it can perform one. In still larger cavities, such as the abdomen, (where often only a partial inflammation takes place, as is frequently the case after childbearing and in wounds of this cavity,) we find this inflammation produced; which either prevents the suppurative altogether, or if it does not, it unites the parts surrounding the suppurative centre, and confines the suppuration to that point; and as the abscess increases in size, the adhesive inflammation spreads, uniting the parts as it spreads, so that the general cavity is excluded. Thus the suppuration is confined to the first point, and forms there a kind of circumscribed abscess, as will be more fully explained hereafter. In inflammations of the pleura or surface of the lungs, the same thing happens, for the adhesive inflammation takes place, and the surfaces are united, which union going before the suppuration confines it to certain limits, so that distinct abscesses are formed by this union of the parts, and the whole cavity of the thorax is not involved in a general suppuration ; such cases are called the spurious empyema. The cellular membrane everywhere in the body is united exactly in the same manner; the sides of the cells throw out, or as it were sweat out, the uniting matter, which fills the cavities and unites the whole into one mass. The adhesive inflammation often disposes the parts to form a cyst or bag; this is generally to cover some extraneous body that does not irritate so much as to produce suppuration, such as a sac formed to inclose a bullet, pieces of glass, &c. With the same wise views it unites the parts or cellular membrane which lies between an abscess and the spot where that abscess has a tendency to open, as will be more fully explained hereafter, when I come to treat of ulceration. The lungs are so circumstanced as to partake of the effects of two principles; the one, as an internal uniting surface; the other, as a secreting surface: the last of which constitutes the peculiar structure and use of this viscus; and the first is no more than the reticular or uniting substance of the air-cells. The internal or the uniting membrane of the lungs unites readily by the adhesive inflammation as the cellular membrane through the body generally; but the aircells, like the inner surface of the urethra, nose, intestines, Sec, pass directly into the suppurative inflammation, and therefore do not admit ofthe adhesive, by which means the matter formed is obliged to be coughed up, which produces symptoms peculiar to the parts affected; and it is perhaps almost impossible to produce an inflammation on either of those two surfaces without affecting the other; which probably is one reason why the treatment of inflammation in those parts is attended with such bad success. We cannot give a better illustration of the use of the adhesions THE ADHESIVE INFLAMMATION. 381 produced in consequence of this inflammation, than to contrast it with the erysipelatous, of which I have already given an account. When the erysipelatous inflammation takes place, the matter gets very freely into the surrounding and sound cellular membrane, and then diffuses itself almost over the whole body; while, in another kind of constitution, the adhesive inflammation would have been produced, to have prevented its progress. A man was attacked with a violent inflammation on each side of the anus, which I did not see till some days after it began. It had the appearance of the suppurative inflammation joined with the erysipelatous; for it was not so circumscribed as the suppurative, no'r did it spread upon the skin like the true erysipelatous, and the skin had a shining oedematous appearance. The inflammation went deeper into the cellular membrane than the true erysipelatous. He was bled; the blood was extremely sizy. He took a purge, and was fomented. He had a difficulty in making water, most probably from the pressure of the swelling upon the urethra. The day following I observed that the scrotum of that side was very much swelled, which had extended up the right spermatic cord; and on examining this swelling, I plainly felt a fluid in it, with air, which sounded on being shaken. The case now plainly discovered itself. I immediately opened the suppuration on each side of the anus, which discharged a dusky-coloured pus, very foetid, with a good deal of air, and upon squeezing the swelling in the scrotum, &c, I could easily discharge the matter and air by these openings; I therefore made him lie principally upon his back, and squeeze these swellings often, with a view to discharge this matter by the openings. The matter at the part where it was formed was not contained in a bag or abscess, but formed in the cellular membrane, without previous adhesion. The scrotum now inflamed, and seemed to have a tendency to open; at least it looked livid and spotted. I opened it at this part, and it discharged a good deal of matter and air. A general suppuration came upon the whole cellular membrane of those parts, and the matter passed up through the cellular membrane of the belly; and the cellular membrane ofthe loins was loaded with matter, from its sinking down from the cells of the abdomen. I made openings there, and could squeeze out a great deal of matter and air. A mortification came on just above the right groin, and when I removed the slough matter was discharged. I also made openings on the loins, on the side of the abdomen, &c. He lived but a few days in this way, during which time the cellular membrane was hanging out ofthe wounds like wet, dirty tow. The adhesive inflammation takes place in consequence of accidents, (when it is impossible it should ever produce the same good effects,) such as wounds which are not allowed to or cannot heal by the first intention; for instance, a stump after amputation, and many other wounds; but it is one of those fixed and invariable principles of the animal machine, which upon all such irritations 382 HUNTER ON THE BLOOD.

uniformly produces the uniting process, though like many other principles in the same machine, the eflects [which it produces] are perhaps not so much required; so that although a wound is not allowed to heal, or cannot heal by means of the adhesive inflammation, yet the surrounding parts "go through the common consequences of being wounded, and the surrounding cells are united ; as was described when I treated of union by the first intention. It first throws out the blood, as if the intention was to unite the parts again; the newly-cut or torn ends of the vessels, however, soon contract and close up, and then the discharge is not blood, but a serum with the coagulating part ofthe blood, similar to that which is produced by the adhesive state of inflammation, so that they go through the two first processes of union; therefore the use of the adhesive inflammation does not appear so evidently in these cases as in spontaneous inflammations: however, in case of wounds which are allowed to suppurate, it answers the great purpose of uniting the cells at the cut surface, from their being simply in contact with each other, as has been described, which confines the inflammation to that part, without which the irritation arising from this state of imperfection might have been communicated from cell to cell, and proceed further than it commonly does. The cut vessels, by this means, are also united, which hinders the progress of inflammation from running along their cavities, as we find sometimes to be the case in the veins of a wounded surface, where this inflammation has not taken place. From everything which has been said it must appear that all surfaces, which are suppurating in consequence of this inflammation, have their basis in that state of the adhesive inflammation which very nearly approaches to suppuration; and this inflammation is less and less as it recedes further from the suppurating centre. CHAPTER IV.

OF THE SUPPURATIVE INFLAMMATION.

When the adhesive inflammation is not capable of resolution, and has gone as far as possible to prevent the necessity of suppuration, especially in those cases that might have admitted of a resolution, as in spontaneous* inflammations in general, where there has neither been an exposed laceration of the solids, nor, as before mentioned, loss of substance, but where the natural functions ofthe part have only been so deranged that it was unable to fall back into

* I have used this word to denote a case where no visible cause of inflammation exists ; for strictly there can be no such thing in nature as spontaneous. THE SUPPURATIVE INFLAMMATION. 383 a natural and sound state again; or, secondly, where it was a consequence of such accidents, as the effects of the adhesive could not in the least prevent, (as in wounds that were prevented from healing by the first or second intention,) then, under either of these two circumstances, suppuration takes place. The immediate effect of suppuration is the production of pus from the inflamed surface, which appears in such cases, or under such circumstances, to be a leading step to the formation of a new substance, called granulations, which granulations are the third method in the first order of parts of restoring those parts to health; but upon all internal canals suppuration is certainly not. a leading step to granulations, which will be explained hereafter. The same theory of the adhesive inflammation respecting the vessels is, I believe, applicable to the suppurative; for when suppuration is the first, we have the vessels in the same state as in the adhesive when it happens, but their dispositions and actions must have altered, there being a great difference in their effects. This is so much the case, that the true inflammatory disposition and action almost immediately ceases upon the commencement of suppuration : and although the vessels may be nearly in the same state, yet they are in a much more quiescent state than before, and have acquired a new mode of action. I shall endeavour to establish as an invariable fact that no suppuration takes place which is not preceded by inflammation; that is, that no pus is formed but in consequence of it. That it is an effect of inflammation only is proved in abscesses from a breach in the solids, attended with exposure, and from extraneous matter of all kinds, whether introduced or formed there. In abscess, suppuration is an immediate consequence of inflammation; from the exposure of internal cavities no suppuration comes on till inflammation has formed the disposition and action ; and although we find collections of extraneous matter, something like pus, in different parts of the body, yet such extraneous matter is not pus. However, towards the last, in such collections, pus is often formed ; but then this is in consequence of inflammation having taken place towards the surface, and when such collections are opened they immediately inflame universally, similar to every other breach ofthe solids, and then the future discharge is pus, all of which I shall now treat. The irritation, which is immediately the cause of suppuration, is the same, from whatever cause it may proceed, similar to that which produces the adhesive stage; it [suppuration] is a similar process going through the same stages, and attended with nearly the same circumstances, whether it takes its rise from external violence, the constitution, or a disposition in the part, if all other circumstances are equal. However, it is not so general in its causes as the adhesive, for the thickening process will take place in many diseases where true suppuration is not admitted, as in some scrofulous cases, some venereal, and also some cancers. Suppuration, therefore, depends more on the soundness of parts than the adhesive 384 HUNTER ON THE BLOOD. inflammation; and this is so much the case that we can, in some degree, judge of a sore simply by its discharge. It appears very difficult to give a true and clear idea ofthe whole chain of causes leading to suppuration. The immediate state of parts, which may be called the immediate cause, 1 conceive to be such as cannot carry on its usual functions of life, and which state of parts I have called the state of imperfection, let the cause of that state be what it will.* We have shown that irritation simply is not always sufficient: it often only brings on the adhesive stage, which is in most cases intended to prevent the suppurative, as has been observed. It is a curious fact to see the same mode of action producing two such contrary effects, and each tending to a cure; the first producing from necessity the second, and being also subservient to it. Violence done to parts is one of the great causes of suppuration ; but w-e have already remarked that violence simply does not always produce this inflammation, but that it must be a violence followed by a prevention of the parts performing their cure in a more simple way, viz., a restoration of the structure, so as [to be able] to carry on the animal functions of the part, or, in other words, a prevention of union by the first or second intention; or [a violence] attended with this circumstance, viz., that the parts are kept a sufficient time in that state into which they were put by the violence ; or, what is something similar to this, a violence attended with death in a part, such as in many bruises, mortifications, sloughs in consequence of caustics, etc., which, when separated, have exposed internal surfaces.]- Various have been the opinions on this subject; and as every violence committed from without, under the circumstances before mentioned, is exposed more or less to the surrounding air, the applications of this matter to internal surfaces has generally been assigned as a cause of this inflammation ; but air certainly has not the least effect upon those parts, for a stimulus would arise from a wound were it even contained in a vacuum.J Nor does the air get

* [To say that the causes of suppuration operate by inducing a "state of imperfection," is, after all, a mere figurative generalization, which does not advance us a single step nearer the solution ofthe difficulty.] f But here we may just remark, that the first processes towards suppuration in cases of mortification, where a separation must take place prior to suppuration, are different from the foregoing, because the living surface is to separate from it the dead parts, and therefore another action of the living powers is required, which is what I call ulceration. And by the phenomena on this occasion, it would appear that nature can carry on two processes at one and the same time; for while the separation is carried on by the absorbents, the arteries are forming themselves for suppuration : so that at the same time the part is goinor through these two very different species of inflammation. X [The admission of fresh air to recent wounds and exposed suppurating surfaces undoubtedly excites pain and eventually an accession of inflammation: which effects were found by Dr. Beddoes to be considerably increased by the use of pure oxygen, and proportionably diminished by the employment of the inert gases, nitrogen, carbonic acid gas, and hydrogen.] THE SUPPURATIVE INFLAMMATION. 385 to the parts that form circumscribed abscesses so as to be a cause of their formation, and yet they as readily suppurate in consequence of inflammation as exposed surfaces. Further, in many cases ofthe emphysema, where the air is diffused over the whole body, (and this air not the purest,) we have no such effect, excepting there is produced an exposure or imperfection of some internal surface for this air to make its escape by, and then this part inflames. Nay, as a stronger proof, and of the same kind with the former, that it is not the admission of air which makes parts fall into inflammation, we find that the cells in the soft parts of birds, and many of the cells and canals of the bones ofthe same tribe of animals, which communicate with the lungs,* and at all times have more or less air in them, never inflame ; but if these cells are exposed in an unnatural way, by being wounded, &c, then the stimulus of imperfection is given, and the cells inflame, and unite if allowed; but if prevented, they then suppurate, granulate, &c. The same observation is applicable to a wound made into the cavity of the abdomen of a fowl, for here the wound inflames and unites to the intestines to make it a perfect cavity again ; but if this union is not allowed to take place, then more or less of the abdomen will inflame and suppurate. If it was necessary that air should be admitted in order for suppuration to take place, we should not very readily account for suppuration taking place in the nose from a cold, as this part is not more under the influence of air at one time than at another; nor is the urethra in a gonorrhoea affected by the air more at that time than at any other. These parts being at all times under the same circumstances with respect to air, therefore there must be another cause. The sympathetic fever has been supposed a cause, which will be considered when I treat ofthe formation of pus. In cases of violence I have endeavoured to give a tolerably distinct idea of the steps leading to suppuration; but we are still at a loss with respect to the immediate cause of those suppurations which appear to arise spontaneously, for in these it is almost impossible to determine whether the inflammation itself be a real disease, viz., an original morbid affection, or whether it may not be (as is evidently the case when from external violence) a salutary process of nature to restore parts whose functions, and perhaps texture, has been destroyed by some previous and almost imperceptible disease or cause. Suppuration being, in cases of violence, a means of restoration, affords a presumption that it is a like instrument of nature in spontaneous cases. If it is the first, viz., a real disease, then two causes that are different in themselves can produce one effect, or one mode of action, for the result of both is the same; but if it is the last, then suppuration must be considered as depending on exactly the

* Vide Observations on certain parts ofthe Animal OJJconomy, Paper 17. 33* 386 HUNTER ON THE BLOOD. same stimulus being given, as in the above-mentioned instance of violence. Suppuration does not arise from the violence of the action ofthe parts inflamed, for that circumstance simply rather tends to produce mortification; and we see that in the gout, which does not suppurate, there is often more violent inflammation than in many others that do. All internal canals likewise suppurate with very slight inflammation, when not in an irritable habit; but if of a very irritable disposition, the action will almost exceed suppuration, and by its becoming milder, suppuration will come on. But if we suppose the cause of inflammation to be a disposition in the parts for such actions, without the parts themselves being either diseased or in such a state as to be similar to the destruction or alteration of their texture, this inflammation then may arise from a vast variety of causes with which we are at present totally unacquainted ; nay, which we do not perhaps even suspect: and this last opinion, upon a slight view, would seem to be the most probable, because we can frequently put back these spontaneous inflammations, which would not be the case if they came on from the destruction of a part, or anything else, whose stimulus was similar to it, for no such thing can be done with wounds: if they are not soon united by the first intention, they must suppurate. However, this argument is not conclusive; for we can prevent suppuration in those arising from accident, by uniting them by the second intention, which prevents suppuration by acting as a kind of resolution. Although suppuration is often produced without much visible violence of action in the part, yet when it is a consequence of a healthy inflammation, we find in general that the inflammation has been violent. It [the suppurative inflammation] is always more violent than the preceding inflammation; and in such cases it would appear to be little more than an increased action, out of which is produced an entire new mode of action, and which of course destroys the first. It is from this violence that inflammation produces its effects so quickly, for the inflammation which is capable of producing quickly so great a change in the operations of the parts, as suppuration, must be violent, because it is a violence committed upon the natural actions and structure ofthe parts. This inflammation will also be more or less, according to the violence ofthe cause producing it, compared with the state of the constitution and parts affected. The inflammation which precedes suppuration is much more violent in those cases where it appears to arise spontaneously, than when it arises from any injury done by violence. A suppuration equal in quantity to that from an amputation of the thigh, shall have been preceded by a much greater inflammation than that which is a consequence of the amputation. THE SUPPURATIVE INFLAMMATION. 387 This inflammation would seem to vary somewhat in its effects, according to the exertion of that power [viz., of the cause] during Us progress; for in proportion to its rapidity [of action] the cause is certainly more simple, and its termination and effects more speedy and salutary ; and this idea agrees perfectly with inflammation in consequence of accidents, for here it runs through its stages more rapidly, and with less inflammation; necessity appears to be the leading cause here. . Thil seems to be the case even in those parts which have a tendency to slow and specific diseases, as, for example, the breasts of women, or the testicles of men ; for if these parts inflame quickly the eflects will be more salutary than if they inflamed slowly. In other words, those parts are capable of being affected by the common suppurative inflammation, which in most cases terminates well Perhaps the specific inflammation is slow in its progress and operation, and such slowness marks it to be an inflammation of some specific kind. In whatever light we view this fact it at least leads us with more certainty to what the effects of an inflammation will be, and thus often to form a just prognostic. Suppuration takes place much more readily in internal canals than internal cavities. Suppuration takes place more readily upon the suriace ol canals than in either the cellular or investing membrane. The same cause which would produce a suppuration in the first parts, would only produce the adhesive inflammation in the other; for instance, if a bougie is introduced into the urethra for a few hours, it will produce suppuration; while, if a bougie was introduced into either the tunica vaginalis testis, or the abdomen, but for a few hours, it would only give the disposition for adhesions, and even might not o-o the length of exciting this stage of inflammation in so short a Time ; butluch surfaces often produce a greater variety of matter than a sore: it is not always pus: and this probably arises from the cause not being so easily got rid of. An irritation in the bladder, from stone, stricture in the urethra, or disease of the bladder itself, gives us a great variety of matter; pus, mucus, slime, are often all found; sometimes only one or two of them. I have some idea that the mucus is easiest of production ; but I am certain that for the formation of slime the greatest irritation is required.

§ 1. The Symptoms of the Suppurative Inflammation.

This inflammation has symptoms common to inflammation in general, but it has these in a greater degree than the inflammation leading to it, and has also some symptoms peculiar to itself; it therefore becomes necessary to be particular in our description of these peculiarities. The sensations arising from a disease generally convey some idea of its nature; the suppurative inflammation gives us as much 388 HUNTER ON THE BLOOD. as possible the idea of simple pain, without having a relation to any other mode of sensation: we cannot annex an epithet to it, but it will vary in some degree according to the nature of the parts going into suppuration; and what was remarked, when treating of the adhesive state, is in some degree applicable here. This pain is increased at the time ofthe dilating of the arteries, which gives the sensation called throbbing, in which every one can count his own pulse, from paying attention merely to the inflamed part; and perhaps this last symptom is one of the best characteristics of this species of inflammation. When the inflammation is moving from the adhesive state to the suppurative, the pain is considerably increased,, which would seem to be the extent of this operation in the part; but when suppuration has taken place the pain in some degree subsides; however, as ulceration begins, it in some degree keeps up the pain, and this is more or less, according to the quickness of ulceration ; but the sensation attending ulceration gives more the . DO idea ot soreness. The redness that took place in the adhesive stage is now increased, and is of a pale scarlet. This is the true arterial colour, and is to be accounted a constant symptom, as we find it in all internal inflammations when at any time exposed, as well as in those that are external. Besides, I observed in the introduction to Inflammation, and when treating of the adhesive state, that the old vessels were dilated, and new ones were formed ; these eflects, therefore, are here carried still further in the surrounding parts which do not suppurate, and constitute two other causes of this redness being increased, by the vessels becoming still more numerous, and the red part of the blood being pushed more forward into many vessels, where only the serum and coagulating lymph went before. The part which was firm, hard, and swelled while in the first stages, or the adhesive state, now becomes still more swelled by the greater dilatation ofthe vessels, and greater quantity of extravasated coagulating lymph thrown out in order to secure the adhesions. The oedematous swelling surrounding the adhesive gradually spreads into the neighbouring parts. In spontaneous suppurations, one, two, three, or more parts of the inflammation lose the power of resolution, and assume exactly the same disposition with those of an exposed surface, or a surface in contact with an extraneous body. If it is in the cellular membrane that this disposition takes place, or in the investing membranes of circumscribed cavities, their vessels now begin to alter their disposition and mode of action, and continue changing till they gradually form themselves to that state which fits them to form pus; so that the effect or discharge is gradually changing from coagulating lymph to pus; hence we commonly find in abscesses both coagulating lymph and pus, and the earlier they are opened the greater is the proportion of the former. This gave rise to the common idea and expression, " That the matter is not concocted;" or THE SUPPURATIVE INFLAMMATION. 389 " The abscess is not yet ripe ;" the real meaning of which is, the abscess is not yet arrived at the true suppurative state. From hence it must appear that suppuration takes place upon those surfaces without a breach ofthe solids or a dissolution ofthe parts, a circumstance not commonly allowed ;*f and when got beyond the adhesive state they become similar in their suppuration to the inner surfaces of internal canals. There is a certain period in the inflammation when the suppurative disposition takes place, which is discovered by new symptoms taking place in the constitution, viz., the shivering. Although the sudden effects produced in the constitution would show that this change of disposition is pretty quick, yet its effects in the parts must be far from immediate, for some time is required for the vessels to be formed by it, so as to produce all the consequences intended by nature; and, indeed, we find it is some time before suppuration completely takes place, and that it is sooner or later, according as the inflamed state is backward in going off; for while the inflammation lasts, the part, as it were, hangs between inflammation and suppuration. The effect of inflammation appears to be the producing of the suppurative disposition, or that state of a part which disposes it to form pus ; in doing this the inflammation seems first to be carried to such a height as to destroy that state of the parts on which itself depends, the consequence of which is, that they lose the inflammatory disposition, and come into that which fits them for forming pus. It seems to be a fixed and most useful law in the animal ceconomy that in spontaneous inflammation, when it has either destroyed the natural functions of parts, so much as to prevent their returning by a retrograde motion, as it were, to the state from whence they set out, or where the first cause was a destruction ofthe natural functions, as an exposure of internal surfaces, that they form a disposition to the second method of cure. The disposition for suppuration is very different from the actual state of inflammation, though produced by it, is proved by a variety of observations, for no perfect suppuration takes place till the inflammation is gone off; and as the inflammation ceases the disposition to suppuration gradually comes

* The knowledge of this fact in some of the larger cavities is not quite new, for I remember about the year 1749 or 1750, that a young subject came under our inspection, and on opening the thorax it was found on the leftside to contain a considerable quantity of pus. Upon examining the pleura and surface of the lungs, they were found to be perfectly entire. This was taken notice of by Dr. Hunter as a new fact, that suppuration could take place without a breach of the surface, and he sent to Mr. Samuel Sharp to see it. It was also new to him, and he published it in his Critical Inquiry. Since that period it has been often observed in the peritonaeal inflammation. J [According to Dr. Thomson (Lectures on Inflammation, p. 316), this doctrine was first distinctly suggested by Dr. Simpson of St. Andrew's, in his Dissertationes de Re Medicd, published in the year 1722. De Haen, in 1756, adopted the same view, and Dr. Morgan more fully in 1763. Still, however, the prevailing opinion may have been different, and Mr. Hunter must certainly be supposed to have known what that was.] 390 HUNTER ON THE BLOOD. on. If, too, by any peculiarity in the constitution, or inflammation by which it is'continued, or if by any accident an inflammation is brought on a healthy sore, the discharge and other appearances become the same as they were when the part from whence they arose was first in an inflamed state, very different from those observed when it was arrived at the state of a kind of suppuration.

§ 2. Of the Treatment necessary in Inflammation when Suppuration must take place.

In cases of inflammation arising from accident, but so circumstanced that we know suppuration cannot be prevented, the practice will be to moderate the inflammation if necessary, but not with a view to prevent suppuration ; for if the powers are very great, and the violence committed very considerable, the inflammation will probably be very violent; and if it should have equal effects on the constitution, which will be in proportion to the quantity of surface inflamed, then certain constitutional means of relief will be necessary, such as bleeding, purging, regimen, and perhaps producing sickness; because, while that inflammation continues to have effects upon the constitution, the suppuration which takes place will not be so kindly as it would otherwise be ; but if the constitution is of the irritable kind, which will be generally known by the inflammation, the same practice as mentioned above is necessary; in short, whatever is to be the consequence, whether resolution or suppuration, the irritability and the too great action of the vessels, whether arising from too great powers, or too great action with small powers, are to be corrected or removed, as they in all cases counteract salutary operations. In cases where the constitution has sympathized much with the inflamed part, such medicines as produce a slight perspiration much relieve the patient, such as antimonials, Dover's powder, saline draughts, spirits of mindererus, etc., because they endeavour to keep up a universal harmony, by putting the skin in good humour (which quiets every sympathizing part), and by counteracting the effects of the irritability. Opium often lessens actions, although it seldom alters them, when only given as an opiate, and may be of a temporary service: however, this is not always a consequence of opium, as there are constitutions where it increases irritation, and of course diseased action. Fresh wounds, considered simply as wounds, are all ofthe same nature, and require one uniform treatment, the intention being to put them into that situation in which they can suppurate with most ease to themselves; and the first dressings commonly remain till suppuration comes on, unless some peculiarity from the situation of parts, or other collateral circumstances, should make it necessary to remove the dressings or vary the treatment. The difference between one wound and another, with respect to THE SUPPURATIVE INFLAMMATION. 391 the nature of the part wounded, will vary very much; some will have small vessels wounded that cannot be conveniently got at, in order to tie them up, yet should be stopt from bleeding, which can be done by the mode of dressing, and therefore require dressing suitable to this circumstance alone. Wounds opening into cavities, where peculiarities of the contained parts are joined with the injury done to them by tbe accident, will require a suitable mode of dressing; the influence, too, that a simple wound in the containing parts may have upon those in the cavity, as a wound into the belly, thorax, joints, skull, etc., will oblige the surgeon to vary the mode of dressing from that of a simple wound; while many wounds will require being kept open for fear of uniting again, in order to answer some future purpose, as the wound made into the tunica vaginalis testis, for the radical cure of the hydrocele; others may require attention being paid to them before suppuration comes on, and therefore should be so dressed as to admit of being soon and easily removed, to examine the parts occasionally as the symptoms arise. This ought to be the case in wounds of the head, attended or not attended with fracture of the skull. But whatever mode of application may be thought necessary to answer the various attending circumstances, yet as they are all wounds which are to come to suppuration, one general method is to be followed respecting them all, as far as those peculiarities will allow. The application which has been made to wounds for some years past in this country has been in general dry lint. What brought this application into common practice most probably was, its assisting to stop the hemorrhage; and as most wounds are attended with bleeding, it became universal; but as it became universal, the first intention was lost sight of, and it became simply a first dressing. I need hardly remark here, that all wounds that are to suppurate are first attended with inflammation, and therefore are so far similar to spontaneous inflammations which are to suppurate. If this observation is just, how contradictory must this mode of treatment be to common practice, when spontaneous inflammation has already taken place ; for let me ask, where is the difference between an inflammation with a wound, and one without 1 And also, what should be the difference in the application to a part that is to inflame (while that application is made to the part), and one applied to an inflammation which has already taken place '\ The answer I should make to such a question is, there is no difference. Wounds that are to suppurate, I have already observed, are first to ^o through the adhesive and suppurative inflammation. These inflammations in a wound are exactly similar to those spontaneous inflammations which suppurate and form an abscess, or those inflammations which ulcerate on the surface, and form a sore. The applications to these which are now in practice, I have formerly observed, are poultices and fomentations; these, however, 392 HUNTER ON THE BLOOD. appear to be applied without much critical exactness or discrimination, for they are applied before suppuration has taken place, and where it is not intended it should take place; they are applied to inflammations where it is wished they should suppurate, and applied after suppuration has taken place. Now, with respect to suppuration itself, abstracted from all other considerations, the indication cannot be the same in all of those states; but if poultices and fomentations are found to be of real service in those two stages of the disease, then there must be something common to both, for which they are of service, abstracted from simple suppuration. I also formerly observed, that poultices were of service when the inflammation had attacked the skin, either of itself, or when an abscess had approached so near that the skin had become inflamed, and that this service consisted in keeping the skin soft and moist. This appears to me to be the use of a poultice in an inflammation, uither before suppuration or after, as inflammation still exists, till it is opened; for inflammation is necessary in an abscess while it is making its approaches to the skin, which I have called the ulcerative; and then, and only then, it begins to subside; it is therefore still proper, inasmuch as it is of service to inflammation; so far, therefore, their practice is right and consistent, as the first reason exists through the whole; but when applied to inflamed parts, which are meant not to suppurate, their reasoning or principles upon which they applied it must fail them, although the application is still very proper. If my first proposition is just, viz., that wounds which are allowed to suppurate are similar to inflammations that are also to suppurate, then let us see how far the two practices agree with this proposition. Lint, I have observed, is applied to a fresh, wound, which is to inflame; and the same lint is continued through the whole of the inflammation till suppuration comes on, because it cannot be removed. Lint, considered simply as an application to fresh wounds which are to inflame, is a very bad one, for it more or less adheres to the surface ofthe wound, by means ofthe extravasated blood; hence it becomes difficult of removal, and often shall remain in sores for months, being interwoven with the granulations, especially when applied to the surface of circumscribed cavities, such as the tunica vaginalis testis, after the operation for the hydrocele; however, this is not always the greatest inconvenience ; the circumstance of its being loaded or soaked with blood, subjects it to become extremely hard when it dries, which it always does before the separation takes place, which separation is only effected by the suppuration. In this way it becomes the worst dressing possible for wounds. As poultices are allowed by most to be the best application to an inflamed part, not attended by, or a consequence of, a wound, but considering it simply as an inflammation, I do conceive that the same application is the best for every inflammation, let it be from whatever cause; for the idea I have of the best dressing to a wound, THE SUPPURATIVE INFLAMMATION. 393 simply as a wound, which is to inflame, is something that keeps soft and moist, and has no continuity of parts, so that it is easily separated. The only application of this kind is a poultice, which, from these qualities, is the very best application to a fresh wound. It keeps it soft and moist, and is at all times easily removed, either in part or the whole. The same medical advantage is gained here, as when it is applied to an inflamed part; but although it had not these advantages, yet the circumstance of being easily removed is much in its favour, especially when compared to dry lint. But a poultice, from other circumstances, cannot at all times and in all places be conveniently applied. To preserve the above properties, it is necessary there should be a mass, much too large for many purposes; but when they can he used with tolerable convenience, they are the best applications. When they cannot be applied with ease, I should still object to dry lint, and would therefore recommend the lint to be covered with some oily substance, so that the blood shall not entangle itself with the lint, but may lie soft, and come easily oft*. This mode of dressing should be continued for several days, or at least till fair suppuration comes on, and when that has taken place, then dry lint may be with great propriety used, except the sore is of some specific kind, which is seldom the case in fresh wounds; for accidental wounds seldom happen to specific diseases; and a wound in consequence of an operation should not be specific, because the specific affection (if there is any) should have been removed by the operation; and should therefore be a wound in the sound part, as after an amputation of a scrofulous joint, or the extirpation of a cancerous breast. Or if they take on some specific disposition afterwards, then they must be dressed accordingly, as will be explained hereafter. Poultices are commonly made too thin, by which means the least pressure, or their own gravity, removes them from the wound ; they should be thick enough to support a certain form when applied. They are generally made of stale bread and milk ; this composition, in general, makes a too brittle application; it breaks easily into different portions from the least motion, and often leaves some part of the wound uncovered, which is frustrating the first intention. The poultice which makes the best application, and continues most nearly the same between each dressing, is that formed of the meal of linseed; it is made at once,* and when applied it keeps always in one mass. Fomentations are generally applied at this stage of the wound, and they generally give ease at the time of application, which has (joined with custom) been always a sufficient inducement to continue them. As soon as suppuration is well established, the part may then be dressed according to the appearances of the sore itself.

* Take boiling water q. s. and stir in the linseed till it becomes of a sufficient thickness, and then add a small quantity of some sweet oil. 34 394 HUNTER ON THE BLOOD. The kind of wound to which the above application is best adapted, is a wound made in a sound part which we intend shall heal by granulation. The same application is equally proper where parts are deprived of life, and consequently will slough. It is therefore the very best dressing for a gunshot wound, and probably for most lacerated wounds. For lint applied to a part that is to throw off a slough will often be retained till that slough is separated, which will be for eight, ten, or more days. In the treatment of wounds that are to suppurate, it is in one view of the subject right to allow the parts to take their natural and spontaneous bent. From the natural elasticity of the skin, and the contraction of muscles, the parts wounded are generally exposed, and from the consequent inflammation they generally become more so. This is commonly more the case in wounds produced by accident; for [in operations], as a small wound and much old skin are always desirable, surgeons very wisely are anxious to wish for both. In many operations they are desirous of preserving the skin, viz., where they are removing parts, as a limb, dissecting out tumours, or opening an abscess; all of which is extremely proper, and they continue to practice upon this principle immediately upon the receiving the wound, and in performing any of the above-mentioned operations; for the skin, after amputation, is drawn down and bound down, and the wounds are pressed together by bandages. In one point of view this is beginning too early ; it is beginning it when nature has the very opposite principle in view: inflammation the parts must submit to, and as inflammation by its effects will generally have a tendency to make them recede more, in this light it is proper not to check the effects of inflammation ; therefore let them take their own way till inflammation subsides and granulations are formed, which granulations, I have already observed, by their power of contraction, will do what we wanted to have done; and if, from some ofthe first circumstances not being properly attended to, the contraction of the granulations is not sufficient, then is the time to assist, and not before. However, if we take up this in another point of view, we shall see a considerable utility arising from bringing the skin as much as possible over the wound, and keeping it there; for in the time of inflammation the parts will adhere or unite in this situation, by which means the sore will be less than it otherwise would; and I conceive that this practice, when begun, should be for some time continued, for fear the adhesions may not be sufficient to stand their ground till the granulations can assist. It often happens in many wounds, both from accident and operations, that part of the wound may with great propriety be healed by the first intention; such as in many accidents on the head, when a part of the scalp has been torn off, on the face, &c, as also after many operations, especially where the skin is loose, as in the scrotum ; or where the skin has been attended to in the time of the. operation, as in some methods of amputation, extirpation of breasts, THE SUPPURATIVE INFLAMMATION. 395 etc., a part of the saved skin, etc., may be made to unite to the parts underneath by the first intention, and therefore only part of the wound be allowed to suppurate. In all such cases a proper contracting or sustaining bandage may be applied with great advantage; even stitches may be used with great propriety, as was recommended in the healing of wounds by the first intention.

§ 3. The Treatment of the Inflammation when Suppuration has taken place.

In spontaneous inflammations, whether from a constitutional or local affection, when suppuration has taken place, it is most probable that another mode of practice must be followed than that which was pursued to prevent it; but even now, if a stop could be put to the further formation of matter, after it has begun, it would in many cases be very proper, and still prevent a great deal of mischief. Suppuration does certainly sometimes stop, after having begun, which shows that there is a principle in the animal osconomy* by which the machine is capable of producing this effect, f I have seen buboes cured by vomits, after suppuration has been considerably advanced, and it is a very common termination of scrofulous abscesses ; but in scrofulous abscesses we very seldom

* [" Animal ceconomy of diseases" in the text.] t I have formerly observed, that the inflammation often goes off without producing suppuration; and I have also mentioned instances of suppuration going off without the parts having produced granulations, and then the parts fall back into the adhesive state, and the matter being absorbed, they are left in nearly the same state as before the inflammation came on : as a presumptive proof of this, in many of the large cavities which have been allowed to inflame and suppurate (by having been opened) we find them often doing well, without ever forming granulations, and that suppuration generally goes off; and I do not believe that they ever fall back into the adhesive state, so as to unite the parts, but the parts resume their original and natural state or disposition, and no adhesions are formed. This appears sometimes to happen in cases of the empyema after the operation has been performed.11 I have seen cases where wounds had been made into the cavity ofthe thorax, where there was every reason to suppose the whole cavity was in a state of suppuration, and yet those patients got well. I can hardly suppose that in these cases the parls had granulated and united in the cure, as the cellular membrane does, because I have seen many similar cases where the patients have died and no granulations have been found; and I have seen cases ofthe hydrocele attempted to be cured radically by the caustic, in which, when the slough came out, suppuration came on, but the orifice healing too soon, suppuration has ceased, and the cure was thought to be completed ; but a return of the disease has led to another attempt, and, by laying open the whole sac, it has been found that the tunica vaginalis was perfectly entire : in such the fluids were a mothery serum. I have seen abscesses go back in the same manner; but I believe that this process is more common to scrofulous suppurations than any other, and I believe to the erysipelatous. I have seen joints heal after having suppurated and been opened, without having produced granulations, leaving a kind of joint, even when the cartilages have exfoliated from the ends of the bones, which was known by the grating ofthe two ends ofthe bones on one another. a [See Principles of Surgery, p. 218, note.] 396 HUNTER ON THE BLOOD. find inflammation. This process appears to be a leading circumstance in ulceration, which is the very reverse of union ;* even in superficial sores, which are the most likely to continue suppuration if excited, we find by allowing them to scab, when they will admit of it, that the act which admits of scabbing is the reverse of suppuration, and it ceases; however, it is a process which the animal ceconomy does not readily accept of, and our powers in producing this effect are but very small. If these powers could be increased by any means it would be a salutary discovery, because suppuration itself in many cases proves fatal: for instance, suppuration of the brain and its membranes, ofthe thorax and its contents, as well as of the abdomen and its contents, in short, suppuration of any of the vital parts, often kills of itself, simply from the matter being produced. But this practice will by most be forbidden in many cases of suppuration, for it is supposed this very suppuration is a deposit of matter or humours already formed in the constitution; but it is to be hoped that time and experience will get rid of such prejudices. When suppuration cannot be stopped or resolved, then in most cases it is to be hurried on, which generally is the first step taken by surgeons. How far suppuration can be increased by medicine or applications I do not know; but attempts are generally made, and thence we have suppurating cataplasms, plasters, &c, recommended to us, which are composed of the warmer gums, seeds, &c, but I doubt very much if they have considerable effect in this way: for if the same applications were made to a sore they would hardly increase the discharge of that sore, but probably rather decrease it. However, in many cases, where the parts are indolent and hardly admit of true inflammation, in consequence of which a perfect suppuration cannot take place, by stimulating the skin a more salutary inflammation may be produced, and of course a quicker suppuration ; but in the true suppuration, where inflammation has preceded it, I believe it is hardly necessary to do anything with respect to suppuration itself: however, from experience, I believe these applications have been found to bring the matter faster to the skin, even in the most rapid suppurations, which was supposed to be an increased formation of matter; but it can only be in those cases where the inner surface ofthe abscess is within the influence ofthe skin. This effect arises from another cause or mode of action being produced than that of quickening suppuration, which is the hastening on of ulceration. I have mentioned that ulceration was an effect of, or at least attended by, inflammation ; and therefore whatever increases that inflammation will also increase the ulceration, which will bring the matter sooner to the skin, without an increased formation of matter.

* [The meaning of the author I apprehend to be, that even in ulceration, which is an act directly opposed to reunion, the cessation or diminution of discharge is a leading circumstance towards the cure.] THE SUPPURATIVE INFLAMMATION. 397 Poultices of bread and milk are commonly used to inflamed parts when suppuration is known to have taken place. These applications can have no effect upon suppuration, excepting by lessening inflammation, or rather making the skin easy under them, for we observed that true suppuration did not begin till inflammation was abated; but the inflammation must have reached the skin before poultices can have much effect, for they can only affect that part. It may be thought necessary that the ease of the patient should be considered, and we find that fomentations and poultices often produce that effect; we find, too, that by keeping the cuticle moist and warm the sensitive operations of the nerves of the parts are soothed or lulled to rest; while, on the contrary, if the inflamed skin is allowed to dry, the inflammation is increased; and as probably suppuration is not checked by such treatment, it ought to be put into practice : as warmth excites action, it is probable the warmer the fomentation so much the better; and in many cases the action is increased so that they can hardly bear it.

§ 4. Collections of Matter without Inflammation.

I have hitherto been describing true suppuration, which I have said, " I believe is a consequence only of inflammation," a process generally allowed. Also in treating on the cause of suppuration, viz., inflammation, I hinted that there were often swellings, or thickening of parts, without the visible or common symptoms of inflammation, viz., without pain, change of colour, &c.; and I also hinted, in treating of suppuration, that there were collections of matter, somewhat similar to suppuration, which did not arise in consequence of the common inflammation: these I shall now consider. I conceive all such collections of matter to be of a scrofulous nature: they are most common in the young subject, and seldom found in the full-grown or old: they are commonly called matter or pus, and therefore 1 choose to contrast true suppuration with them. Although 1 have termed this suppuration, yet it has none of its true characters, any more than the swellings, which are the forerunners of it, have the true characters of inflammation; and as I did not call them inflammatory, strictly speaking I should not call this suppuration ; but I have no other term expressive of it. Many indolent tumours, slow swellings in the joints, swellings of the lymphatic glands, tubercles in the lungs, and swellings in many parts of the body, are diseased thickenings, without visible inflammation; and the contents of some kinds of encysted tumours; the matter of many scrofulous suppurations, as in the lymphatic glands; the suppuration of many joints, viz., those scrofulous suppurations in the joints ofthe foot and hand; in the knee, called white swellings ; the joint of the thigh, commonly called hip-cases ; the loins, called lumbar abscesses; the discharge ofthe above-mentioned tubercles in the lungs, as well as in many other parts of the body, are all instances of matter being formed without any previous visible inflam- 34* 398 HUNTER ON THE BLOOD. mation, and are therefore in this one respect all very similar to one another. They come on insensibly, the first symptom being commonly the swellings, in consequence of the thickening; which is not the case with inflammation, for there the sensation is the first symptom. These formations of matter, although they do not approach the skin, yet do not do it in the same nanner as collections of pus. They do not produce readily either the elongating or the ulcerative process, and as the matter was not preceded by the adhesive inflammation, these collections are more easily moved from their original seat into some other part by any slight pressure, such as the weight of their own matter; from which 1 have called them abscesses in a part, in opposition to abscesses of a part: when the matter does approach the skin, it is commonly by merely a distension ofthe part, coming by a broad surface, not attended with any marks of pointing. Their surrounding parts or boundaries are soft, not being attended with thickening; more especially those in a part. Such collections of matter are always larger than they would have been, if they had been either a consequence of inflammation or attended by it: this is owing to their indolence, allowing of great distension beyond the extent of the first disease, and even of their moving into other parts ; whereas an abscess in consequence of inflammation is confined to the extent of inflammation that takes on suppuration, and its rapid progress towards the skin prevents distension, and of course extension ofthe disease. All those formations of matter not preceded by inflammation, nor a consequence of it, are I believe similar to each other, having in this respect one common principle, very different from inflammation. The cancer, although it produces a secretion, yet does not produce pus till exposed; it is therefore one of those diseases, like the scrofula, which does not suppurate till inflammation conies on, and even seldom then; for true suppuration arises from inflammation, terminating in a disposition to heal, which is not the case with cancer. In the scrofulous suppuration there is often a like reluctance to heal. The kind of matter is another distinguishing mark between that produced in consequence of inflammation and what is formed without it, the last being generally composed of a curdly substance mixed with a flaky matter. The curdly substance is, we may suppose, the coagulating lymph deprived of its serum,* and the other or flaky is probably the same, only in smaller parts; it looks like the precipitate of animal matter from an acid or an alkali. So far these productions of matter in their remote and immediate causes are not in the least similar to that arising from common

* I may observe here that the coagulating lymph of long standing is not similar to the recent. This is similar to blood in general, for we find that the blood in aneurisms, which was first coagulated, is very different from that which has only coagulated lately. THE SUPPURATIVE INFLAMMATION. 399 inflammation; nor is the effect, viz., the matter, similar; and to show still further that suppuration is always preceded by inflammation, the very surfaces which form the above matter immediately produce true matter when the inflammation comes on, which it always does whenever opened; which I shall now consider. Since they are not similar in their causes or modes of production, let us next examine how far they are similar in their first steps towards a cure. All parts which form matter of any kind, viz., whether in consequence of inflammation or otherwise, must go through similar processes to produce the ultimate effect or cure. The first step in either is the evacuation of this matter, for till this is effected, Nature cannot pursue the proper means towards a cure; and if opened, the second step is granulation, and the third cicatrization. To accomplish the evacuation of the matter there are two modes : one is the absorption ofthe matter, which is very common in the scrofula, or those productions of matter not preceded by inflammation : this produces no alteration in the part, except that it gradually creeps into a sound state, the parts uniting again that had been separated by the accumulation of the matter; it produces also no alteration in the constitution: absorption, however, seldom takes place in suppuration which is the consequence of inflammation. The other mode of discharging this matter is either by opening the abscess, in order to allow it to pass out, or by allowing ulceration to take place from the inside to produce its escape ; and this process, in the present case, having peculiarities different from those arising from inflammation, it is necessary they should be understood. Ulceration in consequence of suppuration arising from inflammation is very rapid, especially if the suppuration is so likewise; but ulceration in consequence of matter being formed which is not the effect of inflammation is extremely slow: it will remain months, even years, before the parts have completely given way; they commonly come to the skin by a broad surface, and not pointing like a circumscribed abscess in consequence of inflammation; so far are these two different.*

* [That Mr. Hunter should have overlooked the analogies which connect the class of facts, referred to in this section, with ordinary suppuration, and insisted only on their dissimilarities, might justly excite our surprise, if we did not reflect that his argument is ultimately based on the assumption that inflammation is a salutary process, and not a diseased action ; a doctrine which it is evident could derive no support from the phenomena of chronic abscesses. In this mode of argumentation, however, the same fallacy is involved as in the author's speculations on the venereal disease, in which, having laid down the proposition that mercury is essential to its cure, he afterwards argues on this fact, adopting it as the only unequivocal test ofthe existence of the disease; just as in the present case, having determined that "true suppuration arises from inflammation, terminating in a disposition to heal," the cases which do not correspond with this condition are considered as non-inflammatory. Undoubtedly the symptoms which mark the presence of inflammation in many chronic suppurations are often obscurely developed, but so are those which characterize the adhesive inflammation which precedes the approach of aneurisms and foreign bodies to the surface, or the formation of internal cysts, or the ulceration of the bones of the spine: 400 HUNTER ON THE BLOOD. §5. Of the effects such Formations of Matter have on the Constitution.

Whatever may be the extent of such collections of matter, they seldom if ever affect the constitution, unless they are seated in a vital part, or so connected with it as to disturb its functions. This is an effect of indolence in any disease. A young person shall have a lumbar abscess, for instance, for years, without a single constitutional symptom. It shall appear to be making its way through a number of parts, such as the loins behind, the buttocks, the lower part of the abdomen before, and through the upper part of the thigh ; and in each part shall show large collections of matter. All these shall even attend the same person, and yet not any bad symptoms nor any shiverings shall accompany this suppuration.* In some there is not even the least degree of lameness, but this is often the first symptom of the disease in the lumbar abscess. Let us next consider and compare the consequences attending these two collections of matter when opened. When an abscess, in consequence of inflammation, is opened, it immediately proceeds towards a cure, and perhaps it may have gone some steps towards a cure before opening; the inflammation still lessens, the suppuration becomes more perfect, granulations begin to form, and all of these steps naturally take place, because inflammation had been the cause; but when a collection of matter not preceded by inflammation is opened, a very different process is first to take place, viz., inflammation is now excited over the whole cavity of the abscess, which afterwards produces a perfect matter, similar to that produced in consequence of inflammation, when it is the original disease, and which now produces its constitutional affection, if it is such as to have connexion with the constitution ; but this will depend on the size ofthe abscess, the situation and the nature of the parts,

such indolent swellings, however, and chronic collections of matter, as are referred to by the author, almost always exhibit indications of increased heat, vascularity, and sensibility, when near the surface of the body, while the causes to which they may in most cases be referred, the products in which they commonly result, and the adhesions which invariably accompany their progress, so closely resemble those belonging to genuine inflammation that is impossible to distinguish them. Whatever differences therefore may exist must be regarded as differences of degree. Still, however, the question cannot be considered as decided whether suppuration may not take place independently of inflammation; for large collections of matter are sometimes found to occur simultaneously in various parts ofthe body without any well-defined marks of inflammation before or after death, or even the existence of mischief having been suspected until it has been fully revealed by dissection. Such purulent collections are most commonly found to occur in certain forms of constitutional irritation, of which that attending phlebitis may be regarded as the type, and often present the appearance of purulent metastases. I should conceive, however, that even these cases depend on inflammation, as it often happens that coagulable lymph, either alone or in conjunction with pus, is poured out under such circumstances.] * I have heard surgeons ask such patients if they had rigors, even alluding to the time of increase; this was applying the idea of the symptom of one disease to another, and also the first stage of a disease to the second. THE SUPPURATIVE INFLAMMATION. 401 etc. However, it sometimes happens that they inflame before they are opened; but this is in consequence ofthe matter distending the cavity, and thereby acting as an extraneous body. I have seen white swellings in the knee inflame before they were opened, then ulceration take place, and the pus brought soon to the skin, even after it had been confined for months, without producing the least tendency to ulceration, because there had been none to inflammation ; but the confinement of the matter becomes a cause of the inflammation, and then ulceration takes place. The inflammation and new suppuration taking place in consequence of opening into these abscesses is exactly similar to those arising in consequence of wounds or openings made into natural cavities; it was still, therefore, necessary that they should go through all the common steps towards restoration; but unfortunately such inflammations have begun at the wrong end ; they have also set down upon a specific disease, which they can seldom alter to their own nature. The inflammation is in such cases extended over a much larger surface than the original: which is not the case in abscess in consequence of inflammation, for there the inflammation was the cause and confined to the point. In some cases, as in lumbar abscess, the extent of surface to inflame is immense in comparison to the extent of the original disease; and of course, when such abscesses inflame, the symptoms in the constitution are in the same proportion. How different is this from the opening of the abscess in consequence of inflammation ! There we have no inflammation following, except what arises in consequence of the wound made in the solids in the operation of opening; but when it is allowed to open of itself there is no consequent inflammation, but suppuration goes on. But it would appear that when those collections of matter are allowed to open of themselves, that the succeeding inflammation does not so readily take place as when opened by art. I have seen large lumbar abscesses open of themselves on the lower part of the loins, which have discharged a large quantity of matter, then closed up, then broke out anew, and so on for months, without giving any other disturbance;* but when opened, so as to give a free discharge to the matter, inflammation has immediately succeeded, fever has come on, and, from the situation of the parts inflamed, as well as their extent, death in a very few days after has been the consequence: it therefore often becomes a question whether we should enlarge the first opening or not. We may observe in general that

*" [It was in imitation of this method of Nature that the late Mr. Abernethy suggested the propriety of opening large abscesses by a small valvular aperture, discharging part of the contents, and then healing up the opening. (See his Works, vol. ii.) There is reason to believe that the inflammation which frequently succeeds the discharge of large abscesses in the common way is due to the admission of air, which, acting on the effused blood, or perhaps on the matter itself, occasions decomposition. In this manner the sac is directly irritated, and the constitution greatly disturbed by the absorption of putrid matter.] 402 HUNTER ON THE BLOOD. in cases of this kind, where they are to terminate ill, that is, where they cannot be cured, and are such as to affect the constitution, the consequent inflammation upon opening them, which produces the sympathetic fever, has that fever commonly terminating in the hectic, or continued into the hectic, before any recess takes place, so that the one is continued into the other without any intermission; however, this is not always the case, and those variations "will depend on the state ofthe sore, the state ofthe constitution, &c.

§ 6. The Effects of the Suppurative Inflammation on the Constitution. It is to be observed, that every local complaint of any consequence, or which has considerable and quick action within itself, although not of considerable magnitude, affects more or less the constitution, and gives rise to what has been commonly called the symptomatic fever. These symptoms are the sympathies of the constitution with a local disease or injury, and will vary according to a vast variety of circumstances. They will vary according to the nature of the constitution, which admits of great differences, and which will include different ages; they will vary according to the nature ofthe part in a state of disease, which also admits of great differences ; they will vary according to the quantity of mischief done, as well as the manner of its being done ; that is, whether so as to call forth immediate inflammation, as a wound : or not so immediate, as from having only killed a part: they will vary according to the situation of similar parts in the body; and they will vary according to the stage of the disease. This last variation may be divided into two kinds, the one which begins slowly and increases progressively, as in the venereal disease, and the sympathetic affections of course come on gradually: the other, where it begins at once with violence, and afterwards diminishes. The first of this last division we have nothing to do with at present; it is, therefore, the kind of constitution, the kind of parts, the diseases which commence with so much violence as to affect the constitution at once, with the constitutional effects arising from the local disease being incurable, that form our present subject. I shall observe here, that every disease, whether local or constitutional, that has the power of termination in itself, commonly has its regular progress and stated times of action; in some, however, there are no changes in the modes of action, the disease coming on and dying away; but in others there are; and in those where changes take place there are stated periods for those changes, so as to render them regular. As regularity in the modes of action in disease is conducive to the termination of that disease, it is a thing very much to be desired, for these changes are a cessation of the action, either temporary or permanent. As the constitution sympathizes with a local irritation, and as that THE SUPPURATIVE INFLAMMATION. 403 sympathy is according to the constitution, to the violence of the irritation, and to the nature of the parts irritated; and as the symptoms of that sympathy must be similar to constitutional complaints that are commonly taking place ; if the local complaint should not be known, then they will be taken for constitutional complaints wholly, and treated as such; but often, from their continuance, some local affection is suspected : local complaints, however, are commonly preceded or attended with some local symptom, either directly or indirectly, or with some collateral symptom or symptoms, so as to direct us to the cause. Local complaints attended with inflammations, the objects of surgery, are often attended with, or rather consequent upon, violence of some kind, such as the loss of a part, either fluid or solid, which the constitution feels, and which loss or violence adds to the constitutional affection. This will be according to the quantity of injury or loss of living matter, whether blood or some solid, the time in the operation, the state of the parts operated upon, and the nature of the part removed. I have seen a man die almost immediately upon the loss of a testicle: I have seen convulsions immediately attend the operation for the hydrocele, so that I have almost despaired of recovery: I have seen a most violent sympathetic fever, delirium, and death follow, in consequence of dividing parts in the leg, and searching after a bleeding artery. The loss of a limb above the knee is more than many can bear; the cutting for the stone, where it breaks, and may be an hour in extracting, is also more than many can bear: the parts being in such a diseased state as not to be relieved, have continued the symptoms of the disease: and the loss of a testicle, although of so small a size, when compared with many other parts which we can lose with impunity, yet from its vital connexion is more serious. We cannot bear to lose much brain. The loss of too much blood is often an attendant on, or a consequence of operations, but sometimes takes place without much violence. This produces very considerable constitutional effects; bringing on weakness, and many complaints, depending, as it were, upon debility, which are what are commonly called nervous. I have seen a locked-jaw come on in consequence of the loss of a considerable quantity of blood, the cause of the loss being but trifling, and giving no symptoms whatever. The nature of the cause of inflammation produces, I believe, but little variation in the constitution, for of whatever kind it is, the symptoms in the constitution will be in all cases nearly the same, proportioned only to the violence and rapidity of its progress; and as this [viz., the suppurative] inflammation is pretty violent, more especially if it produces healthy suppuration, it generally produces more violent effects upon the constitution than any other; this, however, will be in some degree according to the susceptibility of the constitution for inflammation; and if any difference takes place in 404 HUNTER ON THE BLOOD. the inflammation in one constitution from that of another, it will arise from the nature of the constitution, and the nature of parts and their situation, and not from the nature of the cause. The sympathy of the constitution with a local disease is what I have called universal sympathy, and is, perhaps, the most simple act of a constitution; it is the sympathy with a simple violence, as a cold, etc., but still it will vary in different constitutions, because all constitutions will not act alike under the influence of a local disease, although it will vary according to the stages of inflammation, according to the natural disposition of the parts inflamed, and according to the situation of those parts in the body ; yet it may be the most simple act of that constitution at the time, for although it would appear at the time to be an increase of the disease by its becoming universal, yet as it is a natural consequence it is a much better sign of health than if no fever had occurred in consequence of considerable injuries, for if there was no inflammation, there would probably be little or no fever. Nature requires to feel the injury; for where, after a considerable operation, there is rather a weak, quiet pulse, often with a nervous oppression, with a seeming difficulty of breathing and a loathing of food, the patient is in a dangerous way. Fever shows powers of resistance; the other symptoms show weakness and sinking under the injury. This is like the effects of the cold bath ; yet we see it calling forth, or rousing up to action, some peculiarity in the constitution, or a part, which may be continued after the sympathetic action is lost, and which may again reflect back upon the part its reluctance to heal. This may be exemplified by the affections of scrofula, and even cancer, arising in consequence of injury.*! Rigors are commonly the first symptom of a constitutional affection ; but a rigor is productive of other eflects or symptoms, as it were naturally arising out of the rigor; and these are according to

* I believe that local specific irritations do not produce much variety in the constitution ; for I am persuaded that specific local irritations are not capable of altering that constitution, similar to the plague and other contagious diseases. I believe that morbid poisons do not act by any peculiar mode of action in the part, so as to affect the constitution in any peculiar way, if weexoept such as are capable of continuing so long as to weaken that constitution, as, for instance, the lues, whpn of long standing; but even this will be similar to every other lasting disease, for at first it certainly does not affect the constitution so as to alter the disposition of a wound made upon another part. I am not so certain respecting natural poisons. The ticunas, poisoned arrow, [Upas tieute",] etc., would seem to produce a peculiar constitutional affection from a local cause, for we can hardly suppose absorption to have taken place in so short a time.a f [" This may' be exemplified by affection or injury, scrofula, even cancer, &c."—Original text.] a [This question, which has been made the subject of a great deal of interesting discussion and experiment of late years, must still be considered as undecided, although, upon the whole, the balance still inclines to the doctrine as here laid down by the author. The late ingenious researches by Mr. Morgan and Dr. Addison on this subject strongly confirm this view.] THE SUPPURATIVE INFLAMMATION. 405 the nature of the constitution. In a strong constitution a hot period succeeds, as if the constitution was roused to action to resist debility, which terminates the rigor; and this hot fit terminates in perspiration, which is the complete action of the disease, restoring tranquillity, which is the cure, and the best termination that can happen where a rigor takes place, for it shows that the constitution has the ■power of terminating the effects of the cause. I believe, however, that in most cases it shows a degree of weakness, especially if easily excited, or a peculiarity of constitution. But as the cause is still continuing in cases of rigor arising from local irritation, these rigors may recur; and if they recur, it shows a constitution ready to be affected; however, if they do recur at stated periods, it still shows the constitution to be able to resist the effects of the disease. Further, if the constitution is weak a rigor comes on, and no hot fit succeeds, but it runs directly into the sweat, which will probably be cold and clammy. If it is a constitution of another kind the hot fit will continue, having only a kind of abatement; but no sweat or perfect intermission will take place, and therefore the whole action has not taken place. Rigors from local irritation, attended with the full action, and at regular stated times, have all the characters of an intermittent fever; but it may be observed that, in common, rigors preceding suppuration are not followed by so much heat and sweating as those in an intermittent. In spontaneous inflammations it is not so easy to ascertain whether the constitution or the part is first affected ; and if we always could, it would be the best guide to know whether the inflammation was local entirely, or an effect of a constitutional affection : nothing but the priority of the symptoms can in some degree fix this; but the constitutional symptoms are often so slight, at least at first, as not to be taken notice of. However, we know that indispositions of the constitution are productive of local complaints, which are often attended with inflammation, but which is often according to the nature of the parts,* the constitution being first diseased; and we know that, in many fevers there is suppuration in some part of the body, and often in particular parts, such as the parotid glands, probably according to the nature ofthe fever; such inflammations will, according to their violence, add to the constitutional affection. Constitutional affection arising from inflammations will be almost coeval with the inflammations, or at least will very soon follow; however, that will be according to the circumstance before related, for inflammation is an act ofthe part, attended with a degree of violence and the constitution will feel it sooner or later, according to circumstances: we see in cases of inflammation of the

* Local inflammations arising from derangement of the constitution I think are most commonly ofthe scrofulous kind, more especially when in parts of a particul ar nature, such as lymphatic glands and ligamentous or tendinous parts, which, when in particular situations, are often supposed to be venereal. , Vide Treatise on Venereal Disease. 35 406 HUNTER ON THE BLOOD. testicles from a gonorrhoea (which must be considered as entirely local,) that the constitution is soon affected by it. But constitutional symptoms arise from external violence alone, and more especially when attended with loss of substance; and they will be sooner or later, according to the degree of the violence, and the importance ofthe parts lost, agreeably to what has been said; but simple violence, even with the loss of a part, I have already observed, is not of such consequence as we should at first imagine, for in consequence ofthe loss of a limb, if the parts are allowed to heal by the first intention, the constitution is but little affected; it is, therefore, violence with loss of substance, and which is to produce inflammation and suppuration, that gives rise to the constitutional symptoms ; and when these commence, or more probably when the part sets about these operations, the constitution becomes affected. It is more the new disposition in the parts, than the quantity of inflammatory action in them, by which the constitution is affected, for we shall see that upon the simple commencement of the suppurative disposition, before it has taken place, rigors, etc., come on. The constitutional effects arising upon the commencement of inflammation, independent of situation, of vital parts, nerves, &c, are greater or less according to the nature of the disease. When the adhesive stage commences it has very little effect upon the whole system; there is sometimes, however, a rigor, although not always ; this is more in common spontaneous inflammations than in those arising from an injury done to a part, but such are seldom or ever alarming. When the suppurative disposition takes place, new eflects upon the constitution arise, which are very considerable and varying in themselves. The cold fits or rigors are more frequently felt at the commencement of the suppurative than at the beginning of the adhesive inflammation, more especially, too, if it is what we commonly call spontaneous inflammations, which advance to suppuration ; for in those inflammations occasioned by an accident or an operation, which must suppurate, they [the inflammations] appear to set out at the very first with a kind of suppurative disposition. Those arising in consequence of spontaneous inflammation, or from an injury, are not lasting, are often succeeded by hot fits, and if they terminate in perspiration then the patient is relieved ; and are more or less so according to the greatness of the present inflammation, and the suppuration that is likely to follow, joined to the nature of the parts and their situation : if in vital parts they will be most violent, and, next to these, in parts far from the heart. This cold fit is indeed a constant symptom in most local diseases which affect the constitution, and in this case plainly shows that the constitution is so affected, or sympathizes with the part. It is thus also that fevers usually commence, and upon the absorption of any poisonous matter the same symptoms appear. I have seen them arise from a simple prick in the end of a finger, made with a clean sewing THE SUPPURATIVE INFLAMMATION. 407 needle,* exactly similar to those arising from the absorption of poison. Disagreeable applications to the stomach produce them, and also disagreeable affections of the mind; but rigors are not confined to the commencement of disease, for they occur in its progress and sometimes at its termination, as will be mentioned. It is probable that the stomach is the cause of those rigors by its taking part in the diseased action of the constitution; for as the stomach is the seat of simple animal life, and thereby the organ of universal sympathy of the materia vitse or the living principle, it is of course more or less affected upon all these occasions; so that an affection of any part of the body and of the mind can produce very nearly the same effect as that which arises from disagreeable applications to the stomach itself; which accounts for that viscus taking part in all constitutional affections. I am inclined to believe that sympathy of the stomach which occasions sickness arises from causes producing weakness or debility. It takes place from injuries or disorders ofthe brain, which occasion universal debility ; it arises from loss of blood, and also from epileptic fits. How far the sickness is to be considered as an effect which is to produce action, viz., vomiting, and which action is to reflect strength back upon the constitution, I do not know; but it is certain that people who are sick and going to faint are prevented by the action of vomiting; the act of vomiting, therefore, appears often to be a cause of the prevention of the fits coming on, by rousing up the actions of life. The rigors I should be apt to suspect arise from weakness at the time. A sudden alteration, a sudden call, or a sudden and universal irritation upon the constitution will, I imagine, produce immediate weakness; for every new action in a constitution must produce or tend to produce a weakness in that function, the effects of which will vary according to the necessity and state of the constitution. In some cases where the constitution is strong, and as it were equal of itself to the task, it will call up the animal powers to action, and produce the hot fit of a fever; but in weak constitutions, or in such as threaten dissolution, as in many diseases, especially towards the close, it loses by every rigor, and is seldom capable of producing a hot fit, but only occasions a cold, clammy sweat; hence cold sweats, when a person is in extremities, is a common symptom. That rigors are an effect of every sudden change in the constitution, and are not peculiar to the commencement of disease, is evident from the following cases; which also prove that even the change to health shall produce the same effect, so that not only in its commencement and in its different stages a disease shall produce rigors, but in its termination or crisis. A boy about eleven months [years?] old was taken ill with a complaint, which could not be well understood from the symptoms, and which came on insensibly: his pulse was quick and full, for

* Hence it would seem as if simple irritation in a part was capable of affecting the whole nervous system. 408 HUNTER ON THE BLOOD. which he was bled three times, and the blood was rather sizy; the tongue was white; he was not very hot, but uneasy and restless, with loss of appetite. His stools were upon the whole pretty natural; he was observed to be every other day rather worse, although there never was a perfect intermission, but only a kind of remission. After having been ill for about a fortnight in this way, he was taken with a cold, shivering fit, succeeded by a hot fit, and then a sweat. My opinion was that the disease was now formed, and that he would have more at the intermitting times; but he had no more after. In short, the disease formed itself into that which has but one fit, and in this formation he had those symptoms. I have seen the same symptoms in many diseases, especially those occasioned by an operation, which in general alarm, but which should not if they go through their stages. A patient of mine, at St. George's Hospital, was cut for the stone : he had no uncommon symptoms for several weeks, when he was taken with a cold fit, which was succeeded by a hot one, and then by a profuse sweat. The young gentlemen of the hospital were rather alarmed, conceiving them to be the signs of dissolution ; but I told them that this was of no consequence, as the disease had completed its full action; that it was either a regular ague, or arose from the irritation of the wound ; and if the first, he would have more of them at stated periods, which the bark would probably cure; but if the second, it might not return, for since the constitution was in the possession of the complete action, that when the parts got better he would be well. He had no more, and went on doing as well as if no such fit had ever taken place. This is not the only instance of this nature. Here it is to be considered that those affections of the constitution are effects of the local action of the solids, either when produced by spontaneous causes or by accident; but there are sometimes constitutional symptoms or universal sympathies, which arise immediately out of the act of violence itself, and which are often dangerous. Loss of blood may be reckoned one cause, which will bring on all kinds of constitutional complaints, in consequence of weakness being produced; either immediate, as fainting, or secondary, as dropsies, as well as nervous affections, the locked jaw, for instance; or violence alone, without the loss of blood, may often produce immediate fatal effects. I have seen a man thrown into such convulsions from the operation of the hydrocele being performed upon him, that I began to despair of his recovery. I have known a man die immediately of castration. These symptoms are somewhat similar to the second, or nervous, but are still very different; for in the present the persons are as it were lost to themselves, being rendered senseless, therefore it is probably more an affection of the brain than the nerves. Another symptom attending inflammation, when it has affected the constitution, is frequent exacerbations, or periods in which the THE SUPPURATIVE INFLAMMATION. 409 inflammation appears to be increased. They have great affinity to the rigors we have been mentioning. Exacerbations are common to all constitutional diseases, and would often appear to belong to many local complaints. They are commonly regular if the constitution is strong, having their stated times, and in proportion as they are so the disease is less dangerous. They are a repetition of the first attack, but seldom so strong, except where there is a perfect cessation in the disease between the fits. This is an attribute belonging to life, and shows that life cannot go on the same continually in any state, but must have its hours of rest and hours of action. In this, as in almost every other symptom of disease, the effect has been considered as a cause; for exacerbations have always been considered as owing to the disease having its time of subsiding or lessening and its time of increase. This idea might pass as just in fevers, where causes are not known ; but where the causes continue the same, as in local diseases, we d priori should not expect it; yet we find in such cases periods of increase and decrease of the symptoms in the constitution, and therefore we must search after some principle belonging to animal life as a cause of this. We shall find that an animal is so constituted as to be incapable of existing for any continuance of time in any one state whatever. The actions of the sensitive principle, when in perfect health, have their regular exacerbations, viz., watching and sleep: it is disease that interrupts this regularity of the actions of health, therefore we find that the actions of disease cannot always go on in the same way; Nature rests insensible of the disease [as in ague], while the disease exists at all times alike. Since this is the case where we see evidently a continuance of the remote cause, and that the constitution is only capable of being affected by this cause at stated times, according to the species of irritation given and the constitution at the time, may we not reasonably suppose this to be the case where the cause is invisible, as in fevers 1 Whether these exacerbations are an effect of an occasional increase ofthe inflammation, or whether the inflammation is increased by the paroxysm of the fever, is not easy to determine; but they attend each other. An ague is a disease which exists in the constitution between the fits as much as at the time of the fit; but the constitution becomes insensible of it, and the action can only last a stated time. The process of ulceration seldom appears to affect the whole system; it is hardly known to exist, but in the appearance of the parts, viz., when the part which contains the matter gets softer to the touch, or when an ulcer becomes larger. But that rigors take place upon the commencement of ulceration I think is evident, although it cannot well be known in all cases; for ulceration will be so close upon suppuration in most cases that it will be difficult to distinguish which was the cause ofthe rigor; but where suppuration has taken place, and the abscess is opened, so that the first 35* 410 HUNTER ON THE BLOOD. act ot suppuration is finished, yet if it is not opened, so as to allow of a ready outlet to the matter, for instance, if it is not opened at a depending part, the pressure of the matter against the most depending part of the abscess will produce ulceration there, and rigors will take place. Those rigors, however, will not commence for some time after the first opening, because the first opening will for some time remove the disposition for ulceration all over the surface ofthe abscess; but when it finds that this opening is not sufficient to take off the pressure, then it sets about forming another opening, and when it does so the rigors will recur, and with as much severity as before. This is supposed by some to be new matter forming from fresh inflammation, and by others to be the absorption of matter already formed. Although ulceration does not affect the constitution equal to the mischief it is doing, yet its operations are often much affected by indispositions of the constitution; in some indispositions its progress is increased; in others it is even brought on, as in many old sores, especially of the lower extremities; and in some indispositions its progress is lessened or stopped. The constitutional symptoms arising from a local complaint may be divided into three as to time, the immediate, indefinite, and remote. Ofthe first, or immediate, there appears to be but one; of the second, there is probably a great variety, at least [a great many] appearing in very different forms and at very different periods, in respect of the original cause. Of the remote there is probably only one. The immediate I shall reckon that which is called the symptomatic fever, and what I shall reckon the second are, nervous affections, as spasms, both temporary and permanent, and delirium. Whether the symptomatic fever, the spasms, or the delirium, come first, is not certain, for often all concur or occur at the same time; but as the sympathetic fever is most constant, and is more an universal principle, it is to be reckoned the first. And the third, which I have called remote, is what is understood by the hectic, to which may be added the symptoms of dissolution, which is the last stage of all, and may be a consequence of either the above or any other disease. The first of the constitutional affections is commonly called the symptomatic fever, but which I choose to call the sympathetic inflammatory fever. This is immediate, or nearly so, and is the sympathy of the constitution, with the first stages of a local disease, which excites an alarm in the constitution, thereby rousing up its powers to produce succeeding actions. This would appear to show very much the nature of the constitution at the time; for not being of any specific nature, both inflammation and fever are led of course into the nature of the constitution by the natural tendency of the constitution itself, and therefore partake of it, and only become more or less of a specific, in proportion as the constitution has more or less of a specific susceptibility or disposition. I have already observed, that affections ofthe constitution often commence with rigor. However, the commencement of the sym- THE SUPPURATIVE INFLAMMATION. 411 pathetic fever is not always attended with that effect, and I believe it is the best constitution where it is not; and in that case i,t changes into a regular fever ofthe inflammatory kind. If the constitution has powers, heat comes on, attended with dry skin, frequent, and commonly a full pulse, having at the same time a degree of hardness in the stroke; watchfulness, high-coloured urine, loss of appetite for solids, and thirst; all these will vary according to various visible circumstances, as well as according to many invisible ones, some one symptom being more in one constitution, and less in another. It is in many instances difficult to determine what is cause and what is effect. It has been commonly supposed that this fever was necessary for the operation of suppuration, and therefore the fever did not arise from the sympathy of the constitution with a local injury, but as a necessary effect to become a cause of suppuration. If this was the case, we could have no suppuration which had not been preceded by fever; and the fever must have been equal in all cases in the same constitution, let the quantity of injury be what it will. For if a pimple, or the suppuration of a scratch, depended upon fever, they would require as much fever for their production of inflammation and suppuration as the largest abscess, or largest wound; for a point that inflames and suppurates is under the same predicament with respect to the whole that a thousand are ; and a large abscess is to be considered as only made up of a thousand points. One venereal sore requires as much mercury to cure it as a thousand. One plant requires as much wet weather and sunshine as a million. A principle that affects universally can only affect a part in proportion to the quantity of the universal affection there is in the part: each part has just its portion of general influence. Now, according to this proposition, which is undeniable, a scratch requires the same°quantity of fever that an amputation of the thigh does. Let us see how this accords with common experience; we find that inflammations and suppurations of sores shall take place without any fever; that the fever, in consequence of an injury, is not in all cases in the least proportioned to the quantity of injury, inflammation, and suppuration, which it always should be if the last was an effect of it; and we know if an increase of fever comes on, superadded to the sympathetic, that suppuration is retarded or stopped altogether instead of being quickened.* From the same mode of reasoning it should be exactly the same, whether the fever produce suppuration in a vital part or in one that is not vital. It is much more easy to conceive that an injury done to a vital part shall be the cause of universal sympathy, than that a vital part should require more fever to make it inflame and

* TThe former and latter parts of this paragraph are plainly contradictory; for if, upon the supposition, a scratch and an amputation require the same quantity of fever, then he degree of fever should not be ... proportion to the suppuration, which however, it is asserted it should be in the latter part of this paragraph.] 412 HUNTER ON THE BLOOD. suppurate than a part does which is not vital. This theory would at once overset our observation that the constitution is affected or sympathizes more readily with some parts than with others. In many cases of spontaneous inflammations and suppurations it was natural to suppose that the fever was the cause ofthe suppuration; but if persons who thought so had observed accurately, they would have divided spontaneous suppurations into two kinds; one, whose remote and immediate cause was local, and therefore in such the fever followed the local action, as [happens] in injuries ; the other, where the remote cause was fever, which produced the injury, and the injury, whatever it was, produced the inflammation and suppuration ; so that here fever preceded, and was necessary for the remote cause, but not as the immediate; and indeed, as a proof of this, suppuration hardly takes place till the fever is gone.* The small-pox is of this last kind, as probably many other contagious diseases. Those symptoms continue, more or less, according to the degree of injury, the nature and situation of parts, and the constitution ; but as they arise from a local cause, which subsides, they of course subside also ; however, as the constitution has often an inflammatory tendency, or a tendency to some other disease, besides the action arising from the violence singly, the parts often run into it, and this is reflected upon the constitution, which passes into that action to which it has a tendency, by which fever is kept up, and thereby inflammation. The subsiding of these symptoms is the cure ; and where they are simply the effects of the violence, the fever cures itself; therefore the only thing necessary is to lessen its violence; but if the injury is of any specific kind, that specific quality must be corrected, if possible, and then the cure will take place. As the motion ofthe blood in the whole system is increased, and as we have reason to suppose it is locally increased, then what will diminish the motion ofthe blood will relieve in this respect. There are two methods of doing this. The first is by taking off its force, and this will be effected by bleeding. This, if it does not lessen its motion, or take off from the sympathy of the constitution with the local disease, yet it lessens the momentum in the whole and in the part, which is taking off the effect of the excess of motion in the blood. The second is by diminishing the action of the parts by affecting the constitution, which may be done by purging; in this light bleeding may also be in some degree considered. It becomes in such cases very necessary to relieve the constitution by lessening the action of that constitution ; for although what has been ad-

* [That is, if I rightly apprehend the passage, the fever is supposed to induce a condition of parts similar to a breach of surface, which state of parts again is supposed to induce a condition of imperfection, which is the immediate cause of the inflammation and suppuration: however, it is difficult to conceive any possible cause of suppuration to which the same mode of reasoning would not be applicable.] THE SUPPURATIVE INFLAMMATION. 413 vised was to lessen the inflammation itself, and thereby lessen its effects on the constitution, yet as that seldom is done sufficiently to remove any affection of the constitution, we must therefore pay attention to that constitution; the two remedies will in some degree go hand in hand, one assisting the other ; for instance, in a strong healthy constitution, where the symptomatic fever runs high, bleeding and purging will have their double effects; but still the constitution may require its peculiar medicines, which will in a secondary way relieve the inflammation. The secondary constitutional symptoms are not so determined as to time; I have called them nervous, although not strictly so in every case, because more variety of affections are produced than from any cause I know ; yet these affections seem all to have more connexion with the nervous than the vascular system, and are severally excited by the particular tendency or susceptibility of different constitutions. Many of them, I believe, are more common to the young than the old, which come under the doctrine of universal nervous sympathy with a local complaint; of this kind are universal convulsions from teething or worms, local convulsions, as St. Vitus's dance, and probably many others not so well marked, as those which worms and teething often produce. I have seen hiccup come on early in consequence of an operation; but in this stage ofthe nervous affection little was to be apprehended, although it certainly showed a peculiarity of constitution, and such as should be attended to; but when hiccup occurs towards the last stages, it shows strong signs of dissolution. Many full-grown persons are also subject to very severe affections of the nervous kind, especially those people who are called nervous; and more particularly still those who have bad affections in consequence of complaints of the stomach. In such constitutions there is observed great dejection, sinking, cold sweats, hardly any pulse, loss of appetite, no sleep, etc., seeming to threaten dissolution ; and those symptoms are worse by fits. Delirium appears to arise from nervous affection of the brain, or sensorium, producing a sympathy ofthe action ofthe brain with the materia vitae ofthe parts; not sensation as a headache, but action producing ideas without the exciting impression, and therefore delusive. This symptom is common to them all [viz., all the constitutional affections]; it is frequently a consequence of their being violent, or carried to considerable length in their several kinds ; often arising in consequence of compound fractures, amputation of the lower extremities, injuries done to joints, brain, etc., but not so often attending the hectic, although it is often a symptom of dissolution. We have agues also fronrTmany diseases of parts, more especially ofthe liver, as also of the spleen, and from induration of the mesenteric glands.*

* [These conditions of the liver and spleen are rather to be regarded as effects than as causes of the ague.] 414 HUNTER ON THE BLOOD. The following cases are remarkable instances of well-marked constitutional diseases from local irritation, where the constitution took on a particular action, to which it had a strong tendency. A gentleman had a very bad fistula in perinaeo from a stricture, and when the water did not come freely an inflammation in the part and scrotum was produced, and then he had an ague, which was relieved for a time by the bark. Two children had an ague from worms, which was not in the least relieved by the bark, but by destroying the worms they were cured. As these diseases which I have brought into this class are of such various kinds, each must be taken up apart, and treated accordingly ; but they are such as yield very little to medicine, for in some the constitutional disease is formed, and does not require the presence of the local disease to keep it up, as in the tetanus; and in others, the local disease being still in force, it is not to be expected that the constitutional affection is to be entirely relieved, although in some degree it may. In those which form a regular constitutional disease, such as an ague, although the local diseases may still exist in full force, yet some relief may be expected ; the bark is to be administered, although not with a view to cure, as the immediate cause still exists ; but bark will in some lessen that susceptibility in the constitution, and may cure, at least for a time, as I have seen in agues arising from the fistula in perinaeo. But the susceptibility in the two children cited above was so strong for such a disease, that the bark was not sufficient; and therefore, when the local cause is not known, and when the common remedies for such effects do not cure them, some local disease should be suspected. We see often such symptoms arising from diseases of the liver, and the bark curing this symptom, yet the liver shall go on with its disease, and probably faster, as I believe bark is not a proper medicine for diseases of this viscus; such complaints of the liver have been too often attributed to the curing of the ague improperly by bark. St. Vitus's dance and many other involuntary actions have arisen from the same cause; such constitutions required only an immediate cause to produce the effects. It is possible, however, that no other mode of local irritation would have produced the same effect, every constitution having a part that is capable of affecting it most. We find also local effects in consequence of local injuries, as the locked jaw, &c, which are remote sympathies with the part affected, which may become pretty universal, and which cannot be called immediate effects as to time, as they are often forming after the sympathetic fever has taken place, especially the locked jaw, which appears in many cases to be formed in the time of the preceding disease, and not appearing till it has subsided. There are certain intermediate steps between the inflammatory and the hectic state; but neither cure nor dissolution takes place in this period. The following case illustrates the effects of inflammation on the constitution :— OF PUS. 415 A lady, of what is called a nervous constitution, arising in some degree from an irritable stomach, often troubled with flatulencies and what are called nervous headaches, with pale urine at those times, uncomfortable feelings, and often sinkings, had a tumour removed from the breast, and likewise from near the armpit; nothing appeared uncommon for a few days, when very considerable disorders came on. She was attacked with a shivering or cold fit, attended with the feel of dying, and followed with cold sweat. It being supposed that she was dying, brandy was thrown in, which soon brought on a warmth, and she was relieved; the fits came on frequently for several days, which were always relieved by brandy ; and she took, in one of the most violent of them, about half a pint of brandy. While under these affections she took the bark as a strengthener; the musk, occasionally, as a sedative in pretty large quantities; camphorated julep frequently, as an antispasmodic; and towards the last she took the valerian in large quantities; but whatever effect these might have in lessening the disease on the whole, they were certainly not equal to it without the brandy. Brandy removed those dying fits, and I thought they became less violent after taking the valerian. A question naturally occurs, Would the brandy alone, if it had been continued as a medicine, have cured her, without the aid of the other medicines ? The other medicines, I think, certainly could not have done it; nor do I believe that the brandy could have been continued in such quantity as to have prevented their returns; if so, then the two modes were happily united, the one gradually to prevent, the other to remove immediately the fits when they came on. This case, from the general tenour of the constitution, was running with great facility into the hectic. CHAPTER V.

Hitherto I have been treating of the operations of parts preparatory to the formation of pus ; I am now come to the formation of that fluid, its nature and supposed uses. The immediate effect of the mode of action above described is the formation of a fluid, commonly termed pus; this is very different from what was discharged in the time of the adhesive stage of the inflammation, when either formed in the cellular membrane or circumscribed cavities; it is also very different from the natural secretions of internal canals, though it is probably formed in both by the same vessels, but under very different modes of action. 416 HUNTER ON THE BLOOD. The cellular membrane, or circumscribed cavities, have their vessels but little changed from the adhesive state at the commencement of the suppurative disposition, so that they still retain much of the form they had acquired by the first state, the discharge being at the beginning little more than coagulating lymph mixed with some serum. This is scarcely different from the adhesive stage of the inflammation; but as the inflammatory disposition subsides, the new disposition is every instant of time altering those vessels to their suppurative state; the discharge is also varying and changing from a species of extravasation to a new-formed matter peculiar to suppuration ; this matter is a remove further from the nature of the blood, and becomes more and more of the nature of the pus; it becomes whiter and whiter, losing more and more of the yellow and green, which it is apt to give the linen that is stained with it in its first stages, and in consistence more and more viscid or creamy. By the formation of this new substance, the coagulating lymph, which was extravasated in the adhesive state of the inflammation, and adhered to the sides of the cells, either in cut surfaces as in wounds, in abscesses, or circumscribed cavities, is pushed off from these surfaces; and if it is the inner surface of a cavity, it is pushed into it, so that the cavity contains both coagulating lymph and pus; or if it is a cut surface, the coagulating lymph is separated from it by the suppuration taking place, and is thrown off; but as such surfaces are generally dressed immediately after the operation, while the wound is bleeding, this blood unites the dressings to the sore, which is assisted afterwards by the coagulating lymph thrown out in the adhesive stage; the whole, viz., dressings, blood, and coagulating lymph, are generally thrown off together, when suppuration commences on these surfaces. This is the process which takes place in the first formation of an abscess, and the first process towards suppuration in a fresh wound. Upon the internal surfaces of the canals the parts do not go through all those steps; they would appear to run into suppuration almost instantaneously ; however, inflammation even here is a kind of forerunner of suppuration. This discharge from internal canals has never been reckoned true matter; it has been called mucus, etc., but it has all the characters of true pus which I am yet acquainted with. Pus is not to be found in the blood similar to that [viz., the coagulable lymph] which was produced in the first stage, but is formed from some change, decomposition, or separation of the blood which that undergoes in its passage out of the vessels, and for effecting which the vessels ofthe parts have been formed which produces a subsiding of the inflammation from which it took its disposition; hence it must appear that the formation of pus consists of something more than a straining of juices from the blood. Many substances indeed which are to be considered as extraneous bodies in the blood, being only mixed with, and not making an essential part OF PUS. 417 of that fluid, and perhaps even [some that are] necessary to it, may pass off with the pus, as with every other secretion, yet the pus is not to be considered on that account as simply parts of the blood unchanged; but we must look upon it as a new combination ofthe blood itself, and must be convinced that in order to carry on the decompositions and combinations necessary for producing this effect, either a new or peculiar structure of vessels must be formed, or a new disposition, and of course a new mode of action of the old must take place. This new structure or disposition of vessels I shall call glandular, and the effect, or pus, a secretion.

^ 1. Ofthe general Opinion of the Formation of Pus. The dissolution of the living solids of an animal body into pus, and that the pus already formed has the power of continuing the dissolution, is an old opinion, and is still the opinion of many, for their language is " Pus corrodes, it is acrid, etc." If this idea of theirs was just, no sore which discharges matter could be exempted from a continual dissolution; and I think it must appear inconsistent, that the matter which was probably intended for salutary purposes should be a means of destroying the very parts which produced it, and which it is meant to heal. Probably they took their idea from finding that an abscess was a hollow cavity in the solids, and supposing the whole of the original substance of this cavity was now the matter which was found in it. This was a very natural way of accounting for the formation of pus by one entirely ignorant of the moving juices, the powers of the arteries, and the operation of an abscess after it was opened ; for the knowledge of these three, abstracted from the knowledge of the abscess before opening, should have naturally led them to account for the formation of pus from the blood by the powers of the arteries alone, for upon their principle these abscesses should continue to increase after opening as fast as before. Upon this principle being established in their minds,, viz., that solids were dissolved down into pus, they built a practice which was to bring all indurated parts to suppuration if possible, and not to open the suppuration in such parts early; this was done with a view to give such solids time to melt down into pus, which was the expression ; but according to their own theory, they seemed to forget that abscesses formed matter after opening, and therefore the parts stood the same chance of dissolution into pus as before. Also, from being possessed of this idea, that solids went into the composition of pus, they never saw pus flowing from any internal canal, as in a gonorrhoea, etc., but they concluded that there was an ulcer; we would forgive such opinions before the knowledge that such surfaces could and generally did form pus without a breach ofthe solids; but that such an opinion should exist afterwards, is not mere ignorance but stupidity • and the very circumstance of internal circumscribed cavities, as the abdomen, thorax, etc., forming pus, where they might ' 36 418 HUNTER ON THE BLOOD. often have seen pints of matter, and yet no breach in the solids to have produced it, which is a proof beyond controversy, should have taught them better; such ideas discover defect of knowledge and incapacity for observation. The moderns have been still more ridiculous; for knowing that it was denied that solids were ever dissolved into pus, and also knowing that there was not a single proof of it, they have been busy in producing what to them seemed proof. They have been putting dead animal matter into abscesses, and finding that it was either wholly or in part dissolved, they therefore attributed the loss to its being formed into pus; but this was putting living and dead animal matter upon the same footing, which is a contradiction in itself; for if the result of this experiment was really according to their idea of it, the idea of living parts being dissolved into pus must fall to the ground, because living animal matter and dead animal matter can never stand upon the same ground. Common observation in their profession should have taught them that even extraneous animal matter would lie in abscesses for a considerable time before it was even dissolved. They might have observed in abscesses arising either from violence or from a species of erysipelatous inflammation, that there were often sloughs of the cellular membrane, and that those sloughs would come away like wet tow, and therefore were not dissolved into pus. They might also have observed in abscesses of tendinous parts, as about the ancle, &c, that often a tendon became dead and sloughed away, and that these sores do not heal till such parts have sloughed, and this is often not accomplished for months, and yet all this time those sloughs are not formed into pus. They might have also known or observed that pieces of dead bone shall lie soaking in matter for many months, and yet not dissolve into pus; and although bones in such situations shall lose considerably of their substance (which might by the ignorant be supposed to have been dissolved into pus) yet that waste can be accounted for and proved on the principle of absorption; for they always lose on that surface where the continuity is broken off, and which is only a continuation of the separating process.* To see how far the idea was just that dead animal matter was dissolved by pus, I put it to the trial of experiment, because I could put a piece of dead animal matter of a given weight into an abscess, and which could at stated times be weighed. To make it still more satisfactory, a similar piece was put into water, kept to nearly the same heat; they both lost in weight, but that in the abscess most, and there was also a difference in the manner, for that in the water became soonest putrid. But these experiments having been made as far back as the year 1757, I shall not rely on their

* It may be supposed that bones are not capable of being dissolved into pus; but we know that bone has animal substance in it, and we also know that this animal subs ance is capable of being dissolved into chyle. OF PUS. 419 accuracy, but state them as made by my brother-in-law Mr. Home, and as given in his Dissertation on the Properties of Pus, p. 32, under the idea that pus had a corroding quality. " As pus has been supposed to have a corroding quality," I may add even upon the living solids, " I made the following experiments to ascertain the truth or fallacy of such an assertion, and found it to be void of foundation, and to have arisen from the inaccuracy of observers having prevented them from seeing the distinctions between pus in a pure state, and when mixed with other substances. " I made a comparative trial upon matter contained in an abscess, and on pus and animal jelly out of the body. The matter and jelly were in equal quantities, and contained in glass vessels, kept nearly in the temperature of the human body. To make the comparative trials as fair as possible a portion of muscle, weighing exactly one drachm, was immersed in the matter of a compound fracture in the arm of a living man, and a similar portion into some ofthe same matter out of the body; also a third portion into fluid calfs-foot jelly, in which the animal substance was pure, having neither wine nor vegetables mixed with it. These three portions of muscle were taken out once every twenty-four hours, washed in water, weighed and returned again. The results were as follows: " In 24 hours the portion of muscle in the abscess weighed sixty grains, was pulpy and soft, but quite free from putrefaction : that portion immersed in the pus weighed forty-six grains, was pulpy, soft, and had a slightly putrid smell: the portion in the jelly weighed thirty-eight grains, was smaller and firmer in its texture. In 48 hours the portion of muscle in the abscess weighed thirty-eight grains, and had undergone no change; that in the matter weighed thirty-six grains, was softer and more putrid ; that in the jelly thirty-six grains and smaller. In 72 hours the portion of muscle in the abscess weighed twenty-seven grains, was drier and firmer; that in the matter eighteen* grains, and was rendered fibrous and thready; that in the jelly unaltered. In 96 hours the portion of muscle in the abscess weighed twenty-five grains; that in the matter was dissolved ; that in the jelly weighed thirty-six grains.* In 120 hours the portion of muscle in the abscess weighed twenty-two grains, not at all putrid; that in the jelly thirty-four grains, not at all putrid. In 144 hours the portion of muscle in the abscess weighed twenty-two grains, and was free from putrefaction ; that in the jelly thirty-four grains." . The supposed facts ofthe solids dissolving being established in the mind as so many data to reason from, they had now no diffi-

* One reason, probably, for the piece of meat so soon becoming putrid and dissolving in the pus was its being kept in the same pus die whole time therefore its disfolution wasowino- more to putrefaction than a disso ving quahty in the pus whereas the piece fn the abscess had its matter continually changing which is the common result in a sore, and if it had a corroding quality independent of h^putrefaction it ought to have been dissolved first; but we may observe that Ihe pTece of muscle in the abscess and the piece in the jelly were nearly upon a par. 420 HUNTER ON THE BLOOD. culty to account for the formation of pus from both the solids and the fluids. Fermentation started up in the mind immediately as a cause; but there must be a cause for fermentation, and according to this idea there are facts which go against it. First, let us consider internal canals, where only mucus is naturally formed, taking on the formation of pus without the loss of substance or any previous ferment, and leaving it off. Now if a fermentation of the solids and fluids was the immediate cause, I should beg leave to ask what solids were destroyed in order to enter into the composition of the pus discharged, for the whole penis could not afford matter enough to form the pus which is discharged in a common gonorrhoea. I should also beg leave to be informed how that fermentation of the fluids ever ceased ; for there is the same surface secreting its mucus whenever the formation of pus ceases. Besides, if dissolved solids enter necessarily into the composition of pus by the power of some ferment, it may be asked, by what power is the first particle of this fluid in an abscess or sore formed, before there is any particle existing which is capable of dissolving the solids? An abscess shall form, and suppuration ceasing, it shall become stationary, perhaps for months, and at last be absorbed, and the whole shall heal; what becomes of the ferment the whole time it is stationary? It has been supposed that blood when extravasated becomes of itself pus; but we find blood, when extravasated either from violence or a rupture of a vessel, as in an aneurism, never of itself becomes pus, nor was pus ever formed in such cavities till inflammation had taken place in them, and then in such cavities there was to be found both the blood and the matter: if the blood had coagulated (as it seldom does in those cases of violence) it would be found still coagulated, and if it had not coagulated the pus would be bloody. True pus has certain properties, which when taken singly may belong to other secretions, but when all joined, form the peculiar character of pus, viz., globules swimming in a fluid, which is coagulable by a solution of sal ammoniac (which no other animal secretion that I know is); and at the same time a consequence of inflammation: these circumstances taken together may be said to constitute pus. As inflammation does not produce at first true pus, I made the following experiments to ascertain its progress or formation. To do this it was only necessary to keep up an irritation on some living part a sufficient time to oblige it to set about the natural consequent actions, and the smooth coat of an internal cavity appeared to me to be well calculated for such an experiment, where nothing could interfere with the actions of the parts or their result; and it would also show its progress on internal surfaces, which shows its progress in wounds and abscesses. OF PUS. 421 § 2. Experiments to ascertain the Progress of Suppuration.

Experiment I. The tunica vaginalis of a young ram was opened and the testicle exposed. The surface of the testicle was wiped clean, and a piece of talc was laid upon it. The surface almost immediately became more vascular; five minutes after, the talc was removed and examined in a microscope, but no globules could be observed, only a moisture, which appeared to be serum. Ten minutes after, there were irregular masses formed on the talc, some transparent, with determined edges, but no globules: fifteen minutes after nearly the same. At twenty minutes there was an appearance of globules. At twenty-five minutes, there were globules in clusters; but I could not say exactly what those globules were. At thirty-five minutes, the globules more distinct, more diffused, and numerous. At fifty-five minutes, the globules still more perfect and distinct. At seventy, the globules more irregular, and of course less distinct. At eighty-five, the globules more distinct and numerous. At one hundred, more irregular and less distinct, forming little masses. At two hours, the masses more transparent, and the globules fewer. At two hours and a half, the masses transparent, and no distinct globules. At four hours, some transparent masses appearing to contain globules. At seven hours, distinct globules and numerous. At eight hours, the globules more distinct and somewhat larger. At nine hours, less appearance of globules. At twenty-one hours, the testicle was covered with lint, and the skin brought over and kept together with a ligature, and allowed to remain for twelve hours (which, from the first, was thirtythree hours); when it was opened it was wiped dry, and a piece of talc applied for five minutes; the quantity of fluid was very small, but containing globules small and numerous. N.B. In this time, during which the testicle was covered, strong adhesions took place between the testicles and tunica vaginalis, which shows that probably the inflammation moved back to the adhesive stage whenever two similar surfaces were opposed. Forty hours, the above repeated and the globules a little more distinct". Forty-four hours, the appearance of globules very distinct, and the pus looked like common matter diluted. Experiment II. An opening was made through the hnea alba below the navel, several inches long, into the cavity of the belly ot a dog, care being taken that no blood should pass into that cavity ; a piece of talc was applied to the peritoneum so as to be covered with the fluid which lubricates that surface; to do which it was found necessary to draw it over some considerable surface. Ihi, fluid was examined in the field of the microscope, and appeared to contain small semitransparent globules, few in number, swimming

U1ThfleUlubricating fluid in the cavity of the abdomen appears, from repeatedI ex^riment. on healthy dogs, to be so small in quantity as '* 36* 422 HUNTER ON THE BLOOD. only to give a polish to the different surfaces, but not sufficient to have a drop collected. After five minutes, the surfaces had more moisture upon them, which being examined as before, the globular appearance was more distinct. In fifteen minutes the surfaces were more vascular; a portion of intestine was wiped dry, and a piece of talc applied to it; the fluid collected on it had a great number of globules, which were smaller than those at first observed. In an hour, this portion of intestine had its blood-vessels considerably increased in number, the whole surface appearing of a uniformly red colour: this was wiped dry, and a piece of talc laid upon it; the fluid collected did not appear to be made up of globules, but of very small parts, which had some transparency, but not exactly regular in their figure, which became still more evident on drying, when they lost the transparency altogether; these were most probably coagulating lymph. This was repeated upon the surface of the spleen, which had its surface excessively red, from the increased number of small vessels, carrying red blood, and the result was exactly similar. From these experiments the fluid which lubricates the peritonaeum seems to undergo changes, in consequence of exposure, and at last, when inflammation takes place, to have coagulating blood substituted for it. Although the lubricating fluid of the peritonaeum is so small in quantity in a natural state, yet before that cavity has been exposed for half an hour the quantity is much increased, and has a mottled appearance of oil and water, but from the appearance in the microscope, it is only an increase of the original fluid with some coagulating lymph, although mistaken by some anatomists for an oily lubricating liquor. Experiment III. At half-past seven o'clock in the morning an incision was made with a lancet into the upper fleshy part of a young ram's thigh, into which was introduced a silver canula, about a quarter of an inch in diameter and three-quarters long, with a great number of small holes in the sides and open at the bottom; it was fastened by means of ligatures to the skin, and a small cork adapted to it. The blood was sponged out several times, and the cork kept in during the intervals. At half-past nine the cork was withdrawn, and the canula was found to contain a fluid; a piece of talc was dipped in it, and the appearance was evidently globular, exactly like the red globules without the colour. At eleven, the quantity of fluid much increased, and the same appearance. At one, the quantity half filling the pipe, of a reddish-brown colour; the globules more numerous, without colour when diluted with water. At three, the quantity considerable, the globules smaller, freer from colour. At half-past five, the same. Experiment IV. In the same manner the canula was introduced into the fleshy part of an ass's thigh, at nine in the morning; and at one o'clock, as also at two, there was a fluid tinged with red globules. At four, there were no diffused globules, but there appeared to be small flakes in a transparent fluid; however, they OF PUS. 423 proved to be clusters of globules. At seven next morning which was twenty-two hours, there was found in the canula common pus. From the experiments on internal surfaces, it would appear that pus was formed coeval with its secretion ; but from Mr. Home's experiments (op. cit., p. 51), it would rather appear that the globules were not formed till some time after secretion, and this sooner or later, according to circumstances, which we probably do not know. So far these experiments explain the progress of suppuration on internal surfaces, and I shall now give its progress on the cutis, when deprived of its cuticle, from Mr. Home's Dissertation on that subject, before mentioned. " I applied a blistering plaster ofthe size of a half-crown piece to the pit ofthe stomach of a healthy young man. In eight hours a blister arose, which was opened, and the contents removed ; they were fluid, transparent, and coagulated by heat: had no appearance of globules when examined by the microscope, and in every respect resembled the serum of blood. The cuticle was not removed, but allowed to collapse, and the fluid which was formed upon the surface of the cutis was examined from time to time by a microscope, to determine as accurately as possible the changes which took place. " The better to do this, as the quantity in the intervals stated below must be exceedingly small, a piece of talc, very thin and transparent, was applied to the whole surface, and covered with an adhesive plaster; and the surface of the talc applied to the skin was removed and examined by the microscope, applying a fresh piece of talc after every examination, to prevent any mistake which might have arisen from the surface not being quite clean. " The fluid was examined by the microscope, to ascertain its appearance; but as the aqueous part in which the globules of pus swim is found by experiment to coagulate by adding to it a saturated solution of sal ammoniac, which is not the case with the serum ofthe blood nor the transparent part of the milk, I considered this as a property peculiar to pus; and consequently that it would be a very good test by which to ascertain the presence of true pus. "In eight hours from the time the blister was applied the fluid discharged was perfectly transparent, and did not coagulate with the solution of sal ammoniac. Nine hours : The discharge was less transparent, but free from the appearance of globules. Ten hours: The discharge contained globules, which were very small, and few in number. Eleven hours: The globules were numerous, but still the fluid did not coagulate with the solution of sal ammoniac. Twelve hours: The appearance much the same as before. Fourteen hours: The globules a little larger, and the fluid appeared to be thickened by a solution of sal ammoniac. Sixteen hours : The globules seemed to form themselves into masses, but were transparent Twenty hours : The globules were double the size of those 424 HUNTER ON THE BLOOD. first observed at ten hours, and gave the appearance of true pus, in a diluted state; the fluid was coagulated by a solution of sal ammoniac, the globules at the same time remaining perfectly distinct, so that I should consider this as true pus. Twenty-two hours: No change appeared to have taken place. Thirty-two hours : The fluid was considerably thicker in consistence, the number of globules being very much increased ; but in no other respect, that I could observe, did it differ from that formed twenty hours after the application of the blister." To ascertain the progress of suppuration on canals or secreting surfaces, I have often examined the matter on a bougie that had been introduced into the urethra, and found it to be formed earlier than either of the times before mentioned: Mr. Home's experiment ■ makes it five hours ; but we often find a gonorrhoea coming on at once, not having in the least been preceded by a leading discharge. Since that period experiments have been made on pus from different kinds of sores, with an intention to ascertain the nature of the sore by the result of such analysis. That sores give very different kinds of pus is evident to the naked eye ; and that the different parts of which the blood is composed will come away in different proportions, we can make no doubt; and we find that whatever is in solution in the blood comes away more in one kind of pus than another, which are all so many deviations from true pus; we may also observe, that such kinds of pus change, after being secreted, much sooner than true pus, which will be observed by and by. From all this I should be apt to conceive that such experiments will throw little light on the specific nature ofthe disease, which is the thing wanted. From such experiments we may find out that pus from a venereal bubo in its height of malady, or that from a cancer is bad matter, but cannot ascertain the difference between those two matters and all others, nor the specific difference between the two. The small-pox, although as malignant a disease as any, and one which produces a pus as replete with poisonous particles as any, yet gives a true pus, when not of the confluent kind, which disposition is not small-pox. The reason why it is good pus is because its inflammation is of the true suppurative kind; and the reason why it is of the true suppurative kind is because the parts have the power of curing themselves, just as much as in any accident which happens to such a constitution; but this is not the case with either the venereal disease or the cancer; from the moment these set out, their dispositions tend to become worse and worse; but the venereal bubo, if mercury is given so as to affect it, soon gives us another kind of pus, although this has the poison equally in it; therefore it is not the circumstance of containing a poison which makes it what is called a bad pus, but its being formed from a sore that has no disposition to heal: as we cannot give healing action to a cancer, so we never can have a good pus. The observation respecting the small-pox is applicable to the venereal gonorrhoea, for this complaint having the power of curing itself, its pus is good in OF PUS. 425 proportion to that power; but as the periods of cure are not so determined as in the small-pox, neither is its time in producing good pus so determined ; but, like the small-pox, as well as the venereal disease, when it is healing we have good pus, although it contains the poison. From the above experiments it must appear unnecessary to give the chemical analyses of what is commonly called pus, for whatever comes from a sore has that name, although very different in many cases from what I should call true pus; and we shall find in those sores that have some specific quality which hinders them from healing, that the discharge is not pus. Probably the chemical properties may be nearly the same in them all.

§ 3. Of the Properties of Pus.

Pus, in the most perfect state, has at the first view certain peculiar qualities. These are principally colour and consistence; but it appears that the colour takes its rise from the largest portion of the whole mass being composed of very small round bodies, very much like those small round globules which, swimming in a fluid, make cream: I should suppose those round globules to be white in themselves, as cream would appear to be, although it is not necessary that the substance of matter which reflects a white should be itself white, for a vast number of transparent bodies being brought together will produce a white, such as broken glass, broken ice, water covering globules of air, making froth, &c. These globules swim in a fluid, which we should at first suppose to be the serum of the blood, for it coagulates with heat like serum, and most probably is mixed with a small quantity of coagulating lymph ; for pus in part coagulates, after having been discharged from the secreting vessels, as mucus is observed to do. But although it is thus far similar to serum, yet it has properties which serum has not. Observing there was a similarity between pus and milk, I tried if the fluid part of pus could be coagulated with the juice of the stomach of other animals, but found it could not. I then tried it with several mixtures, principally with the neutral salts, and found that a solution of sal ammoniac coagulated this fluid : not finding that a solution of this salt coagulated any other of our natural juices^ I concluded that globules swimming in a fluid that was coagulable by this salt was to be considered as pus, and would be always formed in sores that had no peculiar backwardness to heal. The proportion that these white globules in the pus bears to the other parts, depends on the health of the parts which formed it; for when they are in a large proportion the matter is thicker and whiter, and is called good matter; the meaning of which is that the solids which produced it are in good health, for these appearances in the matter are no more than the result of certain salutary processes going on in the solids, the effect of which processes is to produce the disposition on which both suppuration and granulation depend. 426 HUNTER ON THE BLOOD. All this is a good deal similar to the formation of milk; for in the commencement of the secretion of this fluid it is at first principally serum, and as the animal advances towards delivery the globules are forming and become more in quantity, and the animal that has them in largest quantity has the richest milk; likewise when they are naturally leaving off secreting milk, it again takes an exact retrograde motion; and we may also observe, that if any local affection attacks this gland, such as inflammation, the milk falls back to the state I have been now describing; or if any constitutional affection takes place, such as fever, &c, then this gland suffers in the same manner. Pus is specifically heavier than water; it is probably nearly of the same weight with blood or any other animal substance rendered fluid. Pus, besides the above-mentioned properties, has a sweetish and mawkish taste, probably from having sugar in it, which is very different from most other secretions, and the same taste takes place whether it is pus from a sore, viz., an ulcer, or an irritated inflamed surface. Thus, if any have an ulcer in their nose, mouth, throat, lungs, or parts adjacent, so that the matter shall come into the mouth unaltered by putrefaction, they will be able to taste it from its having this property; whereas the mucus and saliva of those parts are tasteless. The same thing happens when an irritation to inflammation takes place on the surface of those parts without ulceration. If the internal surface of the nose is inflamed, so that when we blow it on a white handkerchief we see the substance discharged of a yellow colour, we also find that when we draw up the same substance into the mouth that it has a sweetish, mawkish taste. If it is the surface of the mouth or throat that discharges this matter, the same taste is observable; and if it is brought up from the trachea and lungs, in consequence of the common effects of a cold on those parts the same taste is also to be observed: so that pus, from whatever surface, whether an irritated natural surface or the surface of a common sore, has this property. Pus has a smell in some degree peculiar to itself; but this differs. Some diseases, such for instance as the venereal gonorrhoea, it is pretended may be known by the smell. To ascertain the properties of pus, or to distinguish it from mucus, it has, with mucus, been put to the test of chemisty. Solution in mentrua, and precipitation, were thought to be a test of their distinction. This principle in its very first appearance is unphilosophical, and was at the very first treated by me as absurd. I conceived that all animal substance whatever, when in solution, either in acids or alkalis, would then be in the same state, and therefore that the precipitation would be the same in all. Calcareous earth, when dissolved in an acid, (for instance, the muriatic,) is in that acid in the same state, whether it has been dissolved from chalk, limestone, OF PUS. 427 marble, or calcareous spar; and the precipitations from all are the same. However, whatever my opinion might be, yet bold assertions, the result of described experiments, made me avoid falling into the same error, of describing what I never had seen. I made, therefore, some experiments on this subject; and, in consequence of having previously formed the above-mentioned opinion, I was more general in my experiments. I made them on organic animal matter as well as on inorganic, and the result was the same in all. As organic animal matter, I took muscle, tendon, cartilage, gland, viz., liver and brain: as inorganic animal matter, I took pus and the white of an egg, and dissolved each in the vitriolic acid, and then precipitated the solution with vegetable alkali. Each precipitation I examined with such magnifiers as plainly showed the forms of the precipitate, all of which appeared to be flaky substances. The precipitate by the volatile alkali appeared exactly the same. To carry those experiments a little further, I dissolved the same substance in the vegetable caustic alkali, and precipitated the solution with the muriatic acid, and examined each precipitate with the microscope, and the appearance was the same, viz., a flaky substance, without any regular form. To see how far the nature of sores might be ascertained from the nature of their discharge, matter from a cancerous sore has been analysed, and the result has been that such matter differs from the true pus ; but this explains nothing more than what the naked eye can perceive, that it is not pus, but it will not show the specific difference between the matter from a cancer and matter from a venereal bubo, where mercury has not been given, nor will it tell that one is cancer and the other is venereal. We might as well analyse the urine at different times, in order to ascertain the nature of kidneys at those times. The quality of pus is always according to the nature of the parts which produce it, and whatever specific qualities the parts may have besides, the pus has also this specific quality; hence we have venereal matter from venereal sores, small-pox matter from smallpox sores, cancerous matter from cancerous sores, &c. It is not in the least affected by the constitution, except the parts which produce it are also affected by the constitution. Pus is so far of the same specific nature with the part which produces it, that it does not become an irritator to that part; it is perfectly in harmony with it; the part is not in the least sensible ot it: therefore the pus of a suppurating surface is not an irritator to the same surface, but may be an irritator to any other not ofthe same kind. Hence no suppurating surface of any specific kind can be kept up by its own matter; for if this had not been the case, no sore of any specific quality, or producing matter of an irritating , quality, could ever have been healed. This is similar to every other secretion of stimulating fluids, as the bile, tears, &c, for those 128 HUNTER ON THE BLOOD. do not stimulate their own glands or ducts, but are capable of stimulating any other part of the body. The venereal gonorrhoea, small-pox, &c, healing or recovering of themselves, are striking instances of this. However, we find matter under certain circumstances stimulating its own sore, and also secretions stimulating their own canals, as the secretions ofthe intestines stimulating themselves; but how far this may not arise from one part of the intestines being so diseased as to secrete a stimulating fluid, and coming to a sound part stimulates that only, I will not determine. This I am certain happens to the rectum and anus ; for it very often happens in purging that the watery stools shall irritate those parts so much as to make them feel as if they were scalded. This idea seems reasonable on another principle ; for when we consider matter in the gross, we shall find that it is often mixed with extraneous substances which make no part of it, being probably strained from the blood, and also probably undergoing a change afterwards from its not being pure pus ; nor do these always arise entirely from the nature of the sore, for they are produced by sores of very different specific qualities, it being the species of matter itself which arises from the nature of the sore; however, the kind of sore will often produce more or less of this extraneous matter, and this additional substance may act as a stimulus on every kind of sore. What I have considered thus far is the natural process of a sound constitution and sound parts; since a sore that is going through all the natural stages to a cure is not to be called a disease. A proof of this is, that whenever a real disease attacks either the suppurating surface, or the constitution, these processes of nature are destroyed, and the very reverse take place, the production of true pus ceases, and the fluid becomes changed in some measure in proportion to these morbid alterations ; in general it becomes thinner and more transparent, as if the part was returning back to the adhesive state, it partakes more of the nature of the blood, as is the case in most other secretions under similar circumstances. This in common language is not called pus, but sanies. Pus arising from such state of sores has more of the serum and frequently of the coagulating lymph in it, and less of the combination that -renders it coagulable with a solution of sal ammoniac. It has a greater proportion also of the extraneous parts of the blood that are soluble in water, such as salts, and becomes sooner putrid. The two last species of matter not being of the same specific nature with the sore, they have the power of stimulating even their own sore. On this last account, too, pus becomes more irritating to the adjoining parts with which it comes in contact, producing excoriation ofthe skin and the ulcerative inflammation, as the tears, when they run out, excoriate the skin of the cheek from the quantity of salts which they contain. From this effect the matter has been called corrosive, a quality which it has not; the only quality which it possesses being that of irritating the parts with which it comes in con- OF PUS. 429 tact in such a manner that they are removed out of the way by the absorbents, as will be described when treating on ulceration. In these instances of the change in the pus, we may say that the change is effected by the decomposition and new combination not being carried on so perfectly. This may probably depend on the secreting vessels having lost their due structure and action, and this appears to be so much the case that they not only fail in this operation, but the other offices of those vessels, viz., the production of granulations, is also checked ; for the vessels forming themselves into a certain structure which fits them for secreting pus, it is so ordered that the same structure also fits them for producing granulations: and thus those two processes are concomitant effects of the same cause, which cause is a peculiar organization superadded to the vessels of the part. What organization this may be is not in the least known; nor must we wonder at this, for it is exactly the same with every other organ of secretion, about all which we are equally ignorant. Indeed, some of the differences between one gland and another are made out, and also something of their general structure, but not in such a way as can lead us to the actions and operations of the several parts upon which the nature of the different secretions depend, so as to enable us to conclude c\ priori that this or that gland must secrete this or that peculiar juice. Pus, from several circumstances often attending it, would appear in general to have a greater tendency to putrefaction than the natural juices have; but I very much suspect that this is not really the case with pure pus, when it is first discharged from an abscess it is in general perfectly sweet. There are, however, some exceptions to this, but these depend on circumstances entirely foreign to the nature of pus itself. Thus if the abscess had any communication with the air while the matter was confined in it, (as is frequently the case with those in the neighbourhood of the lungs,) or if it has been so near the colon or rectum as to have been infected by the fseces, under such circumstances we cannot wonder that it becomes putrid. Matter formed early in the state of suppuration, either in abscesses, or more especially in consequence of any external violence committed on the solids, has always in it a portion of blood ; or if some parts of the solids mortify and slough, these will mix with the matter. The same thing happens when the inflammation has something of the erysipelatous disposition, so as to have produced a mortification in the seat of the abscess: in all such circumstances we find the pus has a greater tendency to putrefy than the pure or true pus which comes to be discharged afterwards in sound abscesses or healing sores, and accordingly the matter from recent sores becomes very putrid between every dressing; whereas when the same sores are further advanced it is perfec ly sweet at the same periods. But although the imperfect or heterogeneous matter that is formed at first is liable to putrefy when exposed, yet if it is perfectly confined in an abscess it will remain a considerable 430 HUNTER ON THE BLOOD. time without putrefaction. The suppuration, however, in consequence of the erysipelatous inflammation, which is often attended with suppuration produced by internal mortification, is, as we have observed, an exception to this rule; for although confined from external air, yet the matter becomes soon putrid, and this most probably arises from the solids themselves first becoming putrid. A similar observation may be made with respect to sores which have been in the habit of discharging good pus; for if by any accident an extravasation of blood is produced in these parts, or a disposition is brought on to throw out blood, which mixes with the pus, the discharge changes fromdts former sweetness, and becomes much more putrid and offensive. It appears that pure matter, although easily rendered susceptible of change by extraneous additions, is in its own nature pretty uniform and immutable: it appears so unchangeable, that we find it retained in an abscess for weeks without having undergone any change; but these qualities belong only to perfect pus ; for if a sore from a sound state changes its disposition and becomes inflamed, the matter now produced from it, though there be no extravasated blood or dead solids, becomes much sooner putrid than that which was discharged before this alteration of disposition, and will become much more irritating, as has already been observed. From the above-mentioned considerations we can explain why the discharge in many specific diseases, although not in all, is so much more offensive than in common sores; for in these cases it is commonly not true pus, and is generally mixed with blood. In the same manner, likewise, where there are diseased bones, or other extraneous bodies which excite irritation, sometimes even to so great a degree as to cause the vessels to bleed, and often wounding the vessels of the part, the matter is always found to be very offensive, one mark (although not commonly accounted for) of a diseased bone. Our silver probes are rendered almost black when introduced into the discharge of an unhealthy sore; preparations of lead are the same, when applied to such matter: it even dissolves animal substance. If, for instance, a fresh wound has its lips brought together and held there with sticking-plaster spread upon leather, we shall find, if the wound suppurates, that the parts of the strips of leather going over the wound will be between the first and second dressing quite dissolved, dividing the strips into their two ends ; and the plaster, which commonly has lead in it, shall become black where it has come in contact with this matter. This change in the colour of metals is also produced by eggs when not perfectly fresh, although not become putrid, and probably this property is assisted by the boiling or roasting. Dr. Crawford, in his experiments on the matter of cancers and animal hepatic air [sulphuretted hydrogen], attributes the dissolution ofthe metals to that air.*

The final intention of this secretion of matter is, I believe, not yet understood, although almost every one thinks himself able to assign one; and various are the uses attributed to it. It is by some supposed to carry off humours from the constitution. It is sometimes supposed to be a constitutional disease changed into a local one, and so discharged or thrown out ofthe body, either in form of, or with the pus, as in those cases to be called critical abscesses; but even those who see this final intention are very ready to overturn it, by supposing that this matter is capable of being taken back again into the constitution by absorption, and producing much worse evils than those it was meant to relieve. I believe that the supposed cases of absorption are more numerous than those where it is supposed to relieve; if so, then by their own account nothing is gained. Or it is presumed to carry off local complaints from other parts of the body by way of derivation or revulsion ; for this reason sores, as issues, are made in sound parts, to allow other sores to be dried up, or even with a view to oblige parts to dissolve themselves into pus, as indurated swellings; but we have endeavoured to show that the solids make no part of pus. A secretion of pus is also looked upon as a general prevention of many or of all the causes of disease; issues, therefore, are made to keep off both universal disease as well as local. But I am apt to believe that we are not yet well or perhaps at all acquainted with its use, for it is common to all sores, takes place in the most perfect degree in those sores which may be said to be the most healthy, and especially in those where the constitution is most healthy. We find also that very large discharges, when proceeding from a part which is not essential to life, produces very little change in the constitution, and as little upon being healed up, whatever some people may suppose to the contrary. One might naturally imagine that it was of service to the sore which formed it to keep it moist, &c, for all internal surfaces have their peculiar moisture; but as a sore is to heal, and if allowed to dry so as to form a scab, then a sore is disposed to form no more pus and heal faster, it is the mode of dressing external sores that keeps up this secretion, which in this respect maintains the sore in the state of an internal one. But this will not account for the formation of an abscess, which is the formation of pus we can best account for, since it produces the exposure of internal surfaces: in many cases it is of singular service to procure the second mode of cure, and open a communication between the disease and the external surface of the body. It also forms a passage for the exit of extraneous bodies : but all these are only secondary uses. [The chemical qualities of pus have not yet been accurately investigated, nor do we as yet possess any accurate test for distinguishing mucus 432 HUNTER ON THE BLOOD. from the purulent secretion. Dr. George Pearson, in his observations on this fluid in the Philosophical Transactions, 1810, p. 294, has distinguished four leading varieties, to which all the others may be referred, viz.—1, the healthy, or creamlike and equally consistent; 2, the curdy and unequally consistent; 3, the serous and thin ; and 4, the viscid and slimy. As these, however, under the microscope all exhibit the same intimate structure, consisting of minute particles suspended in a transparent fluid, it is reasonable to infer that whatever differences exist depend on the relative proportions of their constituent parts, or the different degrees of aggregation in which their particles are united. The globular structure of the pus, as first pointed out by Senac, has recently been called in question by the microscopical observations of Messieurs Hodgkin and Lister, who found that the particles above mentioned possessed the utmost variety in size as well as in external configuration. According to Schwilgue pus consists of albumen in a particular state, extractive matter which appears to have no analogy in the healthy state, fatty matter, soda, muriate of soda, phosphate of lime, and other salts. According to some the particles of pus are merely the globules of the blood modified in size and colour, (Gendrin, ii. 479; Andral, Anat. Path. i. 389,) while by others they are regarded as the coagulable lymph existing in a very minute state of division and suspended in the serum of the blood, (Babington, Med.-Chir. Tr., xvi., p. 305,) an idea which agrees pretty nearly with that of Mr. Hunter, who says that " this matter (i. e., the matter which accompanies and precedes the suppurative stage) is a remove further from the nature of the blood, and becomes more and more of the nature of the pus." Pus from mucous membranes is said to contain a greater quantity of albumen than usual; from bone a greater quantity of the phosphates and muriates of lime; from the inflammation of gout a larger proportion of the carbonates and phosphates, and perhaps of the urate of lime ; and from scrofulous abscesses a greater relative proportion of soda and the muriate of soda; but as Mr. Hunter has justly remarked, such facts, even if well established, are of little real value. The formation of pus was first philosophically classed by Mr. Hunter with the other secretions, and shown to be liable to all those modifications to which the secretions in general are subject from constitutional and local causes. M. Gendrin, in his elaborate work on Inflammation, has admitted in general terms the correctness of this doctrine, and yet, inconsistently enough, has attempted to establish, not only the identity of the pus and blood globules, and their gradual metamorphosis intra et extra vascula into pus, but also the transformation of the coagulable products of inflammation after their effusion, so as to revive in almost direct terms the ancient doctrine on this subject of the gradual melting down of the textures. If we examine, he says, a portion of cellular tissue under die microscope, infiltrated with a mixture of bloody serum and pus, we shall observe at the point furthest from the seat of suppuration a simple clear fluid, entirely devoid of globules; a little nearer and we shall perceive globules exactly resembling those of blood; these, as we approach he seat of suppuration, lose a little of their transparency and deprive themselves of their external envelopes, which hang in stria? on their surfaces ; still nearer they have a semi-opaque character and become yellowish ; and finally they assume the genuine characters of pus. He has THE ULCERATIVE INFLAMMATION. 433 been able, he says, to trace these progressive mutations not only in the proper vessels, until it finally exuded on the surface, but also in all the coagulable fluids effused in inflammation, and cites several experiments to this purpose. (Op. cit. ii. 471 et seq. (1447.)) It does not appear to me, however, that the experiments which he has detailed at all warrant the conclusion which he has drawn from them, especially when we take into our consideration the following circumstances; 1, that the pus globules are nearly twice as large as those of the blood, and very irregular in size as well as figure ; 2, that they display no organizable faculty; 3, that the theory assigns two causes, one chemical and the other vital, for the formation of pus (1461), as well as two substances, one globular and the other not so, from which it is formed; and 4, that it is not supported by any analogy in regard to the secretions generally, nor account for the influence which the constitution exercises in modifying the time and mode of suppuration, or the superaddition of specific qualities to the pus. The occurrence of purulent deposits, &c, in vascular coagura, unconnected with the surrounding solids, has been already adverted to (p. 260, note), and has been attempted to be explained by M. Andral by comparing them to the lowest order of animated beings, which, antecedent to any traceable organization, are capable of vital acts and of developing an organization by their own innate forces, similar to embryonic germs. Nay, he does not hesitate to ascribe the origin of parasitic acephalocysts and entozoa to this source (op. cit., p. 377 et seq.) These speculations, however, are scarcely admissable in the present state of science. The only thing which we are able to say with any certainty on this subject is, that these depositions are usually found to coexist with suppurations in other parts of the system, and therefore may with more probability be ascribed to the resorption of matter.] CHAPTER VI.

THE ULCERATIVE INFLAMMATION.

Lv considering the origin and course of the blood, it would have been most natural to have considered absorption, or the absorbing vessels; for in one point of view they may be considered as the animal consisting of so many mouths, everything else depending upon them or belonging to them, for in tracing these dependencies we find that there exists ultimately little else but absorbents. The stomach and the organs connected with it in such animals as have a stomach, are to be considered as subservient to this system; and many an animal is to be considered as consisting of a number of stomachs.* A piece of coral, for instance, appears to be no more than a thousand stomachs, all taking in food for digestion and absorption, for increase and support of the whole; for each stomach does not increase as the piece of coral increases, but they multiply in number, and of course the whole piece of coral increases; * [See note, p. 116.] 37* 434 HUISTER ON THE BLOOD. for although each appears to be a distinct animal yet it is not so. But as this is too general a view of this system for our present purpose, I shall leave it, and confine myself principally to the uses of the absorbents in the diseases of which I am going to treat; and as one of their uses in diseases, and indeed the principal one, has not been described, nor indeed in the least conjectured, that it may be clearly understood or distinguished from the other known uses, I shall relate first the more common uses which have been formerly assigned to this system. First, the absorbents take up extraneous matter, in which is included nourishment. Secondly, superfluous and extravasated matter, whether natural or diseased. Thirdly, the fat. Fourthly, they produce a waste of parts, in consequence of which muscles become smaller, bones become lighter, etc. Although these two last effects were perhaps not expressly said to be carried on by absorption, either by veins or any other system of vessels, yet we must suppose they were understood: so far the absorbents have in general been considered as active parts in the animal ceconomy; but from a further knowledge of these vessels we shall find that they are of much more consequence in the body than has been imagined, and that they are often taking down what the arteries had formerly built up; removing whole organs; becoming modellers of the form of the body while growing; also removing many diseased and dead parts, which were beyond the power of cure ; of all which I shall now take particular notice. As these vessels are productive of a vast variety of effects in the animal ceconomy, which are very dissimilar in the intention and effect, they may be viewed in a variety of lights, and admit of a variety of divisions.* I shall consider them in two views : first, as

* The following tabular statement of Mr. Hunter's classification of absorption is introduced for the convenience of reference. .. .. /. C Extraneous matter to become useful, as chyle, fat, &c. ' , < Interstitial absorption of parts of the body itself, as cellular nourishment. ^ merabrane, muscles, &c. fExtraneous, that ., r\ have been usefuhas Absorption of Ja and Qther _^ secretions, become f Producing wasting of hJD

convenient,or \ , „„ ,. & i s _» , ,, i tf , ' useless. | a part, as a leg, an f As modellers nuruui pans, j partg of thfl bod , arm?&c.; or wasl,ng m the time of L itself. "\ of the whole body. growth. Absorption of the L whole parts. Inconsequence of weakness, J as in the removal of calluses. From parts becomingwholly useless, as the ^alveoli. THE ULCERATIVE INFLAMMATION. 435 they absorb matter, which is not any part ofthe machine ; secondly, as they absorb the machine itself. The first of these is the well-known use, the absorption of matter, which is no part of the machine. This is of two kinds, one exterior matter, in which may be ranked everything applied to the skin, as also the chyle; and the other interior, such as many of the secreted juices, the fat, and the earth of bones, etc.* These are principally with a view to its nourishment, and also answer many other purposes ; so that the action of absorbing foreign matter is extremely extensive, for besides its salutary effects, it is often the cause of a thousand diseases, especially from poisons, none of which are to my present purpose. In the second of these views we are to consider them as removing parts of the body itself, in which they may be viewed in two lights. The first is, where only a wasting is produced in the whole machine or part, such as in the wasting ofthe whole body from an atrophy; or of a part, as in the wasting of the muscles of the leg, etc., from some injury done to some nerve, tendinous part, or joint, all of which I call interstitial absorption, because it is removing parts of the body out of the interstices of that part which remains, leaving the part still as a perfect whole.f But this mode is often carried further than simply wasting of the part; it is often continued till not a vestige is left, such as the total decay of a testicle, so that the interstitial absorption might be understood in two senses. The second is, where they are removing whole parts of the body. This may be divided into the natural and the diseased.J In the natural they are to be considered as the modellers of the original construction of the body ; and if we were to consider them fully in o f c C of a leg, an arm,&c; or of the whole body, C Partial wasting < as in atrophy. Interstitial ab- < ( of a callus, of a testicle. sorption. (Total wasting of calluses, alveoli, testicles, &c. f~A$ when pus or any extraneous body is""| I brought to the skin, | Attended with Progressive | In the process of exfoliation of bones, >• suppuration absorption. <( In the process of sloughing, | '' I In the formation of ulcers, J I In the removal of the fangs of the teeth. Without suppu- L_ ration. Mixed. As in the progress of pus, tumours, &c, to the skin.] < I * It may be necessary to remark here, that I do not consider either the fat, or the earth of bones, as a part of the animal; they are not animal matter; they have no action within themselves. They have not the principle of life. f This mode of absorption has always been allowed or supposed, whether performed by the lymphatic veins or lymphatics. t These uses I claim as my own discovery. I have taught them publicly ever since the year 1772. 436 HUNTER ON THE BLOOD. this view we should find that no alteration can take place in the original formation of many of the parts, either in the natural growth, or that formation arising from disease, in which the absorbents are not in action, and take not a considerable part: this absorption I shall call modelling absorption. If I were to consider their powers in this light, it would lead me into a vast variety of effects, as extensive as any principle in the animal ceconomy, for a bone cannot be formed without it, nor probably many other parts. A part which was of use in one stage of life, but which becomes entirely useless in another, is thus removed. This is evident in many animals; the thymus gland is removed; the ductus arteriosus, and the membrana pupillaris are removed. This process is, perhaps, more remarkable in the changes of the insect than in any other known animal. Absorption in consequence of disease is the power of removing complete parts of the body, and is in its operation somewhat similar to the first of this division, or modelling process, but very different in the intention, and therefore in its ultimate effects. This process of removing whole parts in consequence of disease in some cases produces effects which are not similar to one another; one of these is a sore or ulcer, and I therefore call it ulcerative. In other cases no ulcer is produced, although whole parts are removed, and for this I have not been able to find a term ; but both may be denominated progressive absorption. This process ofthe removal of a whole solid part ofthe body, or that power which the animal ceconomy has of taking part of itself into the circulation by means of the absorbing vessels whenever it is necessary, is a fact that has not in the least been attended to, nor was it even supposed, and having now been noticed, 1 mean to give a general idea of it. I may just be allowed once more to observe, that the oil or fat of animals, and the earth of bones, have always been considered as subject to absorption; and some other parts of the body being liable to wasting, have been supposed to suffer this by absorption; but that any solid part should totally be absorbed is a new doctrine. This use of the absorbents I have long been able to demonstrate, and the first hints I received of it were in the waste of the sockets ofthe teeth, as also in the fangs ofthe shedding teeth. It may be difficult at first to conceive how a part of the body can be removed by itself, but it is just as difficult to conceive how a body can form itself, which we see daily taking place; they are both equally facts, and the knowledge of their mode of action would answer perhaps very little purpose; but this I may assert, that whenever any solid part of our bodies undergoes a diminution, or is broken in upon, in consequence of any disease, it is the absorbing system which does it. When it becomes necessary that some whole living part should be removed, it is evident that nature, in order to effect this, must not only confer a new activity on the absorbents, but must throw the part to be absorbed into such a state as to yield to this operation. THE ULCERATIVE INFLAMMATION. 437 This is the only animal power capable of producing such effects, and like all other operations of the machine, arises from a stimulus or an irritation, all other methods of destruction being either mechanical or chemical. The first by cutting instruments, as knives, saws, etc.; the second by caustics, metallic salts, etc. The process of ulceration is of the same general nature in all cases, but some of the causes and effects are very different from one another. The knowledge of the use of this system is but of late date, and the knowledge of its different modes of action is still later. Physiologists have laboured to account for its modes of action, and the principle of capillary tubes was at first the most general idea, because it was a familiar one. But this is too confined a principle of an animal machine ; nor will it account for every kind of absorption. Capillary tubes can only attract fluids ; but as these inquirers found that solids were often absorbed, such as scirrhous tumours, coagulated blood, the earth of bones, etc., they were driven to the « necessity of supposing a solvent: this may or may not be true; it is one of those hypotheses that can never be proved or disproved, and may for ever rest upon opinion. But my conception of this matter is, that Nature leaves as little as possible to chance, and that the whole operation of absorption is performed by an action in the mouths of the absorbents : but even under the idea of capillary tubes, physiologists were still obliged to have recourse to the action of those vessels to carry it along after it was absorbed, and might therefore as well have carried this action to the mouths of these vessels. As we know nothing of the mode of action of the mouths of these vessels, it is impossible we can form any opinion that can be relied upon; but as they are capable of absorbing substances in two different states, that of solidity and fluidity, it is reasonable to suppose that they have different modes of action; for although any construction of parts that is capable of absorbing a solid may also be such as is capable of absorbing a fluid, yet I can suppose a construction only capable of absorbing a fluid, and not at all fitted for absorbing a solid, though this is not likely; and to see the propriety of this remark more forcibly, let us only consider the mouths of different animals, and I will venture to say that the mouths of all the different animals have not a greater variety of substances to work upon than the absorbents have; and we may observe, that with all the variety of mouths in different animals, this variety is only for the purpose of adapting them to absorb solids, which admit of great variety in form, texture, etc., every one being capable of absorbing fluid matter, which admits of no variety. This process of the removal of parts of the body, either by interstitial or progressive absorption, answers very material purposes in the machine, without which many local diseases could not be removed, and which, if allowed to remain, would destroy the person. It may be called in such cases the natural surgeon. 438 HUNTER ON THE BLOOD. It is by the progressive absorption that matter or pus, and extraneous bodies of all kinds, whether in consequence of or producing inflammation and suppuration, are brought to the external surface; it is by means of this that bones exfoliate; it is this operation which separates sloughs; it is the absorbents which are removing whole bones while the arteries are supplying new ones; and although in these last cases of bones it arises from disease, yet it is somewhat similar to the modelling process of this system in the natural formation of bone; it is this operation that removes useless parts, as the alveolar processes when the teeth drop out, or when they are removed by art; as also the fangs of the shedding teeth, which allows them to drop off; and it is by these means ulcers are formed. It becomes a substitute in many cases for mortification, which is another mode ofthe loss of substance; and in such cases it seems to owe its taking place of mortification to a degree of strength or vigour superior to that where mortification takes place; for although it arises often from weakness, yet it is an action, while mortification is the loss of all action. In many cases it finishes what mortification had begun, by separating the mortified part. These two modes of absorption, the interstitial and the progressive, are often wisely united, or perform their purposes often in the same part which is to be removed; and this may be called the mixed, which I believe takes place in most cases, as in that of extraneous bodies of all kinds coming to the skin; also in abscesses when in soft parts. It is the second kind of interstitial absorption, the progressive and the mixed, that becomes mostly the object of surgery, although the first ofthe interstitial sometimes takes place, so as to be worthy of attention. This operation of the absorption of whole parts, like many other processes in the animal ceconomy arising from disease, would often appear to be doing mischief, by destroying parts which are of service, and where no visible good appears to arise from it; for it is this process which forms a sore called an ulcer, such as in those cases where the solids are destroyed upon the external surface, as in old sores of the leg breaking out anew or increasing; but in all cases it must still be referred to some necessary purpose; for we may depend upon it that those parts have not the power of maintaining their ground, and it becomes a substitute for mortification; and indeed in many ulcers we shall see both ulceration and mortification going on, ulceration removing those parts that have power to resist death.

§ 1. Of the remote Cause ofthe Absorption of the Animal itself.

The remote cause ofthe removal of parts of the animal appears to be of various kinds, and whatever will produce the following effects will be a cause. The most simple intention or object of nature seems to be the THE ULCERATIVE INFLAMMATION. 439 removal of a useless part, as the thymus gland, membrana pupillaris, ductus arteriosus, the alveoli when the teeth drop, or the crystalline humour after couching, and probably the wasting ofthe body from fever, either acute or hectic. These parts are removed by the absorbents, either as useless parts, or [in the latter case] in consequence of strength being unnecessary while under disease, or such as not to accord with disease.* Another cause is a weakness, or the want of power in the part to support itself under certain irritations, which may be considered as the basis of every cause of removal of whole parts, as the absorption of calluses, cicatrices, the gums in salivation ; also that arising from pressure or irritating applications, under which may be included the attachment of dead parts to a living one, all of which may be accounted for upon the same principle of parts or organs not being able to support themselves under the present evil. From the above account of the final cause of the absorption of whole parts from disease, it would appear that they are capable of being absorbed from five causes. First, from parts being pressed; secondly, from parts being considerably irritated by irritating substances ; thirdly, from parts being weakened; fourthly, from parts being rendered useless; fifthly, from parts becoming dead. The two first, for instance, parts being pressed and parts being irritated, appear to me to produce the same irritation : the third, or weakness, an irritation of its own kind; and the fourth, or parts being rendered useless, and the fifth, or parts becoming dead, may be somewhat similar. It is probable that every cause above enumerated is capable of producing every mode, or rather effect, of absorption, whether interstitial or progressive; but pressure attended with suppuration always produces the progressive, whether applied externally or internally, as in the case of abscesses.

§ 2. Ofthe Disposition of living Parts to absorb and to be absorbed.

The disposition of the two parts of the living body, which absorb and are absorbed, must be of two kinds respecting the parts, one passive and the other active. The first of these is an irritated state of the part to be absorbed, which renders it unfit to remain under such circumstances, the action excited by this irritation being incompatible with the natural actions and the existence ofthe parts, whatever these are, which therefore become ready for removal, or yield to it with ease. The second is ,the absorbents being stimulated to action by such a state of parts, so that both conspire to the same end. When the part to be absorbed is a dead part, as nourishment or

* It might be asked as a question, whether the waste of the constitution in disease arises from the body becoming useless when under such diseases, as may be observed of muscles when their joint, tendon, &c, is diseased, or whether it accords better with the diseased state, and may even tend to a natural cure ? 440 HUNTER ON THE BLOOD. extraneous matter of all kinds, then the whole disposition is in the absorbents. When the immediate causes arise in consequence of pressure, it would appear that absorption takes place more readily under certain circumstances than others, although the remote causes of them appear to be the same, and therefore there is something more than simple pressure. For we find that pressure from within produces ulceration or absorption much more readily than from without, for if it was pressure only, absorption then would be according to the quantity of pressure; but we find very different effects from the same quantity of pressure under the above-mentioned circumstances; for when from without, pressure rather stimulates than irritates, it shall give signs of strength, and produce an increase of thickening; but when from within, the same quantity of pressure will produce waste, for the first effect of the pressure from without is the disposition to thicken, which is rather an operation of strength ; but if it exceeds the stimulus of thickening then the pressure becomes an irritator, and the power appears to give way to it, and absorption of the parts pressed takes place, so that nature very readily takes on those steps which are to get rid of an extraneous body, but appears not only not ready to let extraneous bodies enter the body, but endeavours to exclude them, by increasing the thickness of the parts. Many parts of our solids are more susceptible of being absorbed, especially by ulceration, than others, even under the same or similar circumstances, while the same part shall vary its susceptibility according to circumstances. The cellular and adipose membranes are very particularly susceptible of being absorbed, which is proved by muscles, tendons, ligaments, nerves, and blood-vessels being found frequently deprive^ of their connecting membrane and fat, especially in abscesses, so that ulceration often takes a roundabout course to get to the skin, following the track of the cellular membrane; and the skin itself, when the pressure is from within, is much less susceptible of ulceration than the cellular and adipose membrane, which retards the progress of abscesses when they are so far advanced, and also becomes the cause of the skin's hanging over spreading ulcers, which are spreading from the same cause, more especially too if the part ulcerating is an original part. Ulceration never takes place on investing membranes of circumscribed cavities, excepting suppuration has taken place; and indeed ulceration in such parts would be a sure forerupner of suppuration. New-formed parts, or such as cannot be said to constitute part ofthe original animal, as healed sores, calluses of bones, especially those in consequence of compound fractures, admit more readily of absorption, especially the progressive, than those parts which were originally formed. This arises probably from the principle of weakness, and it is from this, too, that all adventitious new matter, as tumours, are more readily absorbed than even that which is a THE ULCERATIVE INFLAMMATION. 441 substitute for the old. Thus we have tumours more readily absorbed than a callus of a bone, union of a tendon, &c, because they have still less powers than those which are substitutes for parts originally formed. Ulceration in consequence of death in an external part take,s place soonest on the external edge between the dead and the living. This is visible in the sloughing of parts; for we may observe that sloughs from caustics, bruises, mortification, &c, always begin at the external edge. An internal pressure produced by an extraneous body acts equally on every side of the surrounding parts, and therefore every part being pressed alike ought, from this cause alone, to produce absorption ofthe surrounding parts equally on all sides supposing the parts themselves similar in structure, or, which is the same, equally susceptible of being absorbed; but we find that one side only of the surrounding living parts is susceptible of this irritation, therefore one side only is absorbed; and this is always the side which is next to the external surface of the body. We therefore have always extraneous bodies of every kind determined to the skin, and on that side to which the extraneous body is nearest, without having any effect, or producing the least destruction of any of the other surrounding parts. From this cause we find abscesses, &c, whose seat is in or near the centre of a part, readily determined to the surface on the one side and not on the other; and whenever the lead is once taken, it immediately goes on. But as some parts from their structure are more susceptible of this irritation than others, we find that those parts composed of such structure are often absorbed, although they are not in the shortest road to the skin: this structure is the cellular membrane, as will be taken notice of hereafter. We find the same principle in the progress of tumours; for although every part surrounding a tumour is equally pressed, yet the interstitial absorption only takes place on that side next the external surface, by which means the tumour is, as it were, led to the skin. From hence we find that absorption of whole parts more readily takes place to allow an extraneous substance to pass out of the body than it will to allow one to pass in. Thus we see that the slight pressure produced by matter on the inside of an abscess has a great effect, and the matter is brought much faster to the skin (although very deep) than it would by the same quantity of pressure applied from without; and indeed so slight a pressure from without would rather tend to have an opposite effect, namely, that of thickening. The reasons of this are evident: one is, a readiness in the parts to be freed from a disease already existing; the other is, a backwardness in the parts to admit a disease. This principle therefore in the animal ceconomy produces one of the most curious phenomena in the whole process of ulceration, viz., the susceptibility which the parts lying between .an extraneous body and the skin have to ulcerate, while all the other sides of the abscess are not 442 HUNTER ON THE BLOOD. irritated to ulceration; and the necessity there is that it should be so must be very striking; for if ulceration went on equally on all sides of an abscess, it must increase to a most enormous size, and too great a quantity of our solids must necessarily be destroyed. Bones, we have observed, are also subject to similar circumstances of ulceration; for whenever an abscess forms in the centre of a bone, or an internal exfoliation has taken place, the extraneous body acts upon the internal surface of the cavity, and produces ulceration. If the matter or dead piece of' bone is nearer one side than the other, ulceration takes place on that side only; and here too the provision of Nature in abscesses comes in, for the adhesive inflammation extends itself on the outside in proportion as ulceration extends itself on the inside of the cavity, and as ulceration approaches to the surface of the bone the adhesive disposition is given to the periosteum, then to the cellular membrane, &c. And what is very curious, this adhesive inflammation assumes the ossifying disposition, which I have called the ossific inflammation, and appears as a spreading ossification, in the same manner as in the callus of a simple fracture. The consequence of these two processes taking place together in bones is very singular, for the ulcerative process destroying the inside of a bone while the ossifying makes addition to its outside, the bone often increases to a prodigious size, as in cases of spina ventosa ; but in the end the ulceration on the inside gets the better, and the matter makes its escape. Nature has not only made what might be called an instinctive provision in the parts to remove themselves, so as to bring extraneous bodies to the skin for their exit, and thereby from this principle has guarded the deeper-seated parts, but has also guarded all passages or outlets where, from reasoning, we might suppose no great mischief could arise from bringing extraneous bodies thither; and in many cases a seeming advantage would be gained, such passages appearing to be more convenient for the exit of such matter, and likely to produce less visible mischief in procuring them. Thus a tumour in the cheek, close on the internal membrane of the mouth and some way from the skin, shall in its growth push externally, especially if there is matter in it, and in time come in contact with the skin and adhere to it, while it. shall have made no closer connexion with the skin of the mouth. If it should suppurate, and more especially if it be of a scrofulous kind, which is slow in its progress, it will break externally; we even see abscesses in the gums opening externally, where the matter has been obliged to go a considerable way to get to the skin. The same guard is set over the cavity of the nose : if an abscess forms in the antrum, frontal sinus, or saccus lachrymalis, all of which are nearer to the cavity of the nose than the external surface of the body, ulceration does not follow this shortest way, which would be directly into the nose, but leads the matter to the nearest external surface. THE ULCERATIVE INFLAMMATION. 443 I have seen an abscess in the frontal sinus first attended with great pain in the part, then with inflammation on the whole forehead, at last matter has been felt under the skin, and on being opened it has led into one or both sinuses, and almost the whole bone has exfoliated. For such an abscess the nearest passage would have been directly into the nose. Abscess in the lachrymal sac, forming what is called the fistula lachrymalis, arises also from the same cause. A curious circumstance takes place here : but whether peculiar to this part or not, I do not yet know: besides the disposition for ulceration externally at the inner corner of the eye, there is a defence set up upon the inside, so that the membrane of the nose thickens very considerably. How far a thickening takes place on the inside of the nose, opposite to the antrum, in abscesses of that cavity, or how far it is a universal principle in other passages, I have not been able to learn, but I am incline to believe it is not universal. From this principle we can see why openings made into these passages to make the matter come that way are more unsuccessful than reasoning (without the knowledge of this principle) would lead us to believe; the opening, therefore, should not be made on the inside, (even where we can do it,) excepting the matter is very near, or else the opening should be made very large ; and probably in such cases it may be necessary to take out a piece, so as to prevent the uniting process, which is here very strong. Illustrations will be given in other passages, when treating of ulceration in general tending to the external surface.

§ 3. Of Interstitial Absorption.

Interstitial absorption, I observed, was of two kinds with respect to effect, or rather had two stages. The first was where it took place only in a part, as in the wasting of a limb in consequence of its being rendered useless, whether from disease in a joint, a broken tendon, or the dividing of a nerve, whereby its influence is cut off; or where it takes place in the whole body in consequence of some disease, as in acute fever, hectic fever, diabetes, atrophy, or the like. The second is the absorption of a whole part, where not a vestige is left. This [latter] would seem to be of two kinds: one where it is only in consequence of another disease, and is a necessary and useful effect of that disease, as assisting in bringing parts to the surface; but the other appears to arise from a disease in the part itself, as the total decay of the alveoli, without any disease in the teeth or gums, which however in the end suffer, as also the total wastino- of a testicle, the absorption of a callus, &c. It is the first of these two kinds which is most to my present purpose, and deserves our particular attention. It takes place in a thousand instances: we find it gradually taking place in the part of the body which happens to lie between encysted tumours and the external surface, when they are making their way to the skin. This absorption is commonly slow in its progress, so much so as even to make the ultimate 444 HUNTER ON THE BLOOD. effect, although considerable, not sensible till a certain length of time has elapsed. This mode of removing parts appears to arise from pressure, as in the former; but here some principles are reversed. The contents of an encysted tumour do not give the stimulus of removal to that side of the cyst nearest to the external surface, as happens in an abscess, so as to produce a' removal of the surface pressed by its contents, which would be the progressive ulceration, as in our first division; but the tumour gives the stimulus to the sound parts, between it and the skin, and an absorption of those parts takes place, similar to that which I suppose takes place in the removal of calluses of bones from weakness. We find whenever an encysted tumour is formed in the cellular membrane, it in time makes its approaches towards the skin, by the cellular membrane and other parts between it and the skin being absorbed, so that the whole substance between the cyst and skin becomes thinner and thinner, till the cyst and the external skin meet or come in contact, and then inflammation begins to take place; for as the parts are now soon to be exposed, inflammation lakes place to produce a quicker absorption, which borders often upon ulceration. The mode of action in this last case may be, in one respect, very similar to the foregoing solid tumour, for besides the interstitial absorption, the cyst may be looked upon as a tumour acting upon or stimulating the parts between it and the skin; therefore the tumour causes absorption of the contiguous cellular membrane upon which it presses. This process of interstitial absorption of parts is very evident, even in common abscess; and where a progressive absorption is going on, it is assisted by this. I have already observed that the interstitial absorption is not attended with, nor does it produce, suppuration.

§ 4. Ofthe Progressive Absorption.

The first or principal mode of this action is the removing of those surfaces that are immediately contiguous to the irritating causes, which is an absorption of necessity. These causes, I have observed, are of three kinds: one, pressure; another, irritating substances; and the third, considerable inflammation in a weak part, especially those new-formed parts that become a substitute for the old. Absorption from pressure is the removal of the part pressed, which may arise from a number of causes, There are tumours which, by pressing upon neighbouring parts, produce it; the pressure of the blood in aneurisms produces it, etc.; also that surface of an abscess, or any other extraneous body which is nearest the external surface;* or the ulceration of that part of the surface of the body which is in contact with a body pressing, as the buttocks or hips of those who lie long upon their backs; the heels of many people

* [" also that surface of an abscess which is in contact with the pus, or any other extraneous body."—Original text.] THE ULCERATIVE INFLAMMATION. 445 who lie long in the same position, as is the case with those who are under the cure of a fracture of the leg, in which case it seems to be a substitute for mortification, and is rather a proof of the strength of the patient; for if very weak constitutionally, the same parts certainly mortify; as also the constant pressure of chains on the legs of prisoners, and harness on the breasts of horses. The second of these causes of absorption is the action of irritating substances, such as the tears passing constantly over the cheeks; as also many irritating medicines, producing too much action, and probably at the same time weakening the parts. The third is the formation of an ulcer or sore on a surface, in consequence of some disease, which has been the cause of inflammation. Bones are subject to the same effect from pressure as the soft parts, as in consequence of aneurisms; as also from the pressure from tumours: likewise in cases of the spina ventosa, where in some there is nothing to be found in the cavity of the swelling but blood coagulated, in others a grumous or curdly substance. This blood or curdly substance increasing, continues the pressure, and the inside ofthe bone is in time absorbed. I have already observed that the progressive absorption is divisible into two kinds; one without suppuration, the other with. I shall now observe that the absorption which does not produce suppuration may take place either from pressure made by sound parts upon diseased parts, or by diseased upon sound parts; as the effect that the pressure of the coagulated blood has in aneurisms, the moving blood in the same, which is a sound part, contained in diseased arteries and not capable of supporting the pressure of the moving blood; as also many tumours, which are diseased parts, pressing upon natural sound parts; and these diseased parts are simply endowed with life, which I apprehend makes some difference in the effects respecting the formation of pus; also uncommon pressure made by such substances as are not endowed with any irritating quality sufficient to produce the suppurative inflammation, as a piece of glass, a lead bullet, etc., all of which I shall now more fully explain. Of this* first division, viz., from pressure without suppuration, we have several instances, as in aneurisms, especially when they are in the aorta, and principally at the curve; and when arrived at a considerable size, so as to press against the surrounding parts, particularly against the back bone, as also against the sternum; all of which will be according to the situation of the aneurism: we find in such cases, that, from the dilatation of the artery (which arises from the force of the heart) the artery is pressed against those bones, and that the substance of the artery at the part pressed is taken into the constitution. This absorption begins at the external surface of the artery, where it comes in contact with the bone, and continues there till the whole artery is absorbed ; then the bone itself comes in contact with the circulating blood, and not being naturally intended to be washed by moving blood, the bone & J 38* 446 HUNTER ON THE BLOOD. or bones are also absorbed from this pressure and motion of the blood against them. The adhesive or strengthening disposition takes place in the surrounding parts, and is of great service here, as it unites the circumference ofthe unabsorbed part of the artery to the surrounding parts; as also the cellular membrane beyond the surface of absorption (when in soft parts), similar to the preceding adhesive inflammation going before ulceration in an abscess; but it is here much stronger, for strength is wanted as well as adhesion while it is dilating; so that a cavity of some strength for the moving blood is always kept entire, and no extravasation can take place, nor can the parts readily give way. Another instance of this absorption occurs in those cases where living tumours make their way to the skin without the formation of an abscess. I once saw a remarkable instance of this in a Highland soldier in the Dutch service, who had a solid tumour formed, either in the substance of the brain, or, what is more probable, upon it, viz., in the pia mater, for it seemed to be covered by that membrane: the tumour was oblong, above an inch thick, and two or more inches long; it was sunk near its whole length into the brain, seemingly by the simple effects of pressure; but the outer end of it by pressing against the dura mater, had produced the absorbing disposition in that membrane, so that this membrane was entirely gone at that part. The same irritation from pressure had been given to the skull, which also was absorbed at this part; after which the same disposition was continued on to the scalp. As these respective parts gave way, the tumour was pushed further and further out, so that its outer end came to be in this new passage the absorbents were making for it in the scalp, by which it probably would have been discharged in time if the man had lived; but it was so connected with the vital parts that the man died before the parts could relieve themselves. While all these exterior parts were in a state of absorption, the internal parts which pressed upon the inner end ofthe tumour, and which pressure was sufficient to push it out, did not in the least ulcerate; nor did the tumour itself, which was pressed upon all sides, in the least give way in its substance. No matter was to be observed here from either the dura mater, the unconnected edge of the bones of the skull, nor from that part ofthe scalp which had given way; and perhaps the reason was, the tumour being a living part, and not an extraneous one. The general effect was, however, similar to the progress of an abscess, insomuch that it was on that side nearest to the external surface of the body that the irritation for absorption took place. This first species of the absorption of whole parts is seldom or never attended with pain. Its progress is so very slow as to keep pace with our sensations, and in many cases it is not even attended with inflammation.. I believe that this absorption seldom if ever affects the constitution, although in some cases it takes its rise from affections of the constitution, as in the cases of the absorption of callus. THE ULCERATIVE INFLAMMATION. 447 § 5. Of Absorption attended with Suppuration, which I have called Ulceration.

I shall now give an account of that part of the actions of the absorbing system which I call ulceration, and which is the second of our first division respecting the formation of pus, viz., that which is connected with the formation of that fluid, being either a consequence of it, or producing it, and is that which in all cases constitutes an ulcer. It is this which principally constitutes the progressive absorption.* This differs from the foregoing in some circumstances of its operations. It either takes place in consequence of suppuration already begun, and then the pus acts as an extraneous body, capable of producing pressure: or absorption attacks external surfaces from particular irritations or weakness, in which case suppuration, forming an ulcer, must follow, let the cause of that breach of loss of substance be what it may. In order to produce ulceration from pressure, I may again take notice that it requires a much greater pressure from without than from within; and when it is from within, the ulceration is quicker when near to the skin than when deep or far from it; the nearer it is to the skin the more readily inflammation takes place; and I have also observed that inflammation, although it takes place in deep-seated parts, yet it seldom or never extends-deeper, but approaches towards the external surface ; and as inflammation seems to precede, and is essential to this process, we see the reason why it should take place sooner if near to the skin, and go on faster the nearer it comes to it. The process of ulceration which brings matter to the external surface is not wholly the absorption of the inner surface of the abscess, for there is an interior or interstitial absorption of the parts lying between the inner surface of the abscess and the skin, similar to the approach of encysted tumours, as has been described. And besides this assistance, I have already observed, there is a relaxing and elongating process carried on between the abscess and the skin, and at those parts only where the matter appears to point. This process of ulceration, or absorption with suppuration, is almost constantly attended by inflammation ; but it cannot be called an original inflammation, but a consequent, which gave rise to the term ulcerative inflammation. It is always preceded by the adhesive inflammation, and perhaps it is simply this inflammation which

* I have given it the term ulceration, because ulcer is a word in use to express a sore, and it is by this process that many ulcers are formed. The operations produced in ulceration have not hitherto been in the least understood therefore a very erroneous cause of these operations has been always supposed. It has always been supposed that those solids which were visibly gone were dissolved into pus; from whence arose the idea of matter being composed of solids and fluids, which we have endeavoured to refute. 448 HUNTER ON THE BLOOD. attends it. We find the adhesions produced answering very wise purposes; for although the adhesive inflammation has preceded the suppurative, and of course all the parts surrounding the abscess are united, yet if this union of the parts has not extended to the skin, where the abscess or matter is to be discharged, in such a case, wherever the ulceration has proceeded beyond the adhesions, there the matter will come into unadhering parts; the consequence of which will be that the fluid or matter will diffuse itself into the cellular membrane of the part, and from thence over the whole body, as in the erysipelatous suppuration ; but to prevent this effect, the adhesive inflammation takes the lead of ulceration. There are many other causes of ulceration, which operate on surfaces, where we do not see the same necessity for it, when the matter formed can be and is discharged without it; such parts are, many old sores, the inside of the stomach and intestines, and indeed all the surfaces above mentioned ; which do not admit readily of the adhesive inflammation, under some circumstances admit of the ulcerative. This effect would appear to arise from the violence of the inflammation, the parts being so weakened, either by it, or some former disease, that they can hardly support themselves; for we find in salivations, where the whole force of the mercury has been determined to the mouth, they have become weakened by long and violent action ; the gums and inside of the mouth will ulcerate ; also, from the same weakening disposition the gums will ulcerate in bad scurvies; therefore weakness joined with inflammation, or violence of action, appears to be the immediate cause in such cases. The effect then of irritation, as above described, is to produce first the adhesive inflammation in such parts as will readily, admit of it, and if that has not the intended effect, the suppurative takes place, and then the ulceration comes on to lead the matter already formed to the skin, if it is confined. The natural consequence of suppuration in such parts is the growth of new flesh, called granulations, which are to repair the loss the parts have sustained by the injury done ; but in all outlets, where the adhesive would be hurtful, the irritation first only produces the suppurative inflammation ; but if carried further, the adhesive will take place, as has been described ; and as in such parts the matter formed has an outlet, ulceration is also avoided; and as in such cases no parts are destroyed, granulations are also excluded. There appears to be a curious circumstance attending ulceration, which is the readiness with which it seems to absorb every other substance applied to it, as well as the body itself; at least this appears to be the case with the small-pox after inoculation, as also the venereal chancre, whether arising from the absorbents at the time being in the act of absorbing, or whether they promiscuously absorb what is applied along with the parts themselves. In such cases it might be a question also whether the parts of the body which they THE ULCERATIVE INFLAMMATION. 449 do absorb have the same disposition with the pus of that part, as in the cancer, and therefore contaminate the constitution, as 'in the small-pox and venereal disease, as readily as if it was the'pus. From what has been observed, it must appear that any irritation which is so great as to destroy suddenly the natural operations of any one part, and the effect of which is so long continued as to oblige the parts to act for their own relief, produces, in some parts, first the adhesive inflammation ; and i,f the cause be increased, or continue still longer, the suppurative state takes place, and all the other consequences, as ulceration ; or if in the other parts, as secreting surfaces, then the suppurative takes place immediately, and if too violent, the adhesive will succeed; or if parts are very much weakened the ulcerative will immediately succeed the adhesive, and then suppuration will be the consequence. This species of ulceration in general gives considerable pain, which pain is commonly distinguished by the name of soreness; this is the sensation arising from cutting with an instrument, which operation is very similar to ulceration; but this pain does not attend all ulcerations, for there are some of a specific kind which give little or no pain, such as the scrofula; but even in this disease, when the ulceration proceeds pretty fast, it gives often considerable pain; therefore the pain may be in some degree proportioned to the quickness of its operation. The greatest pain which in general attends this operation arises from those ulcerations which are formed for the purpose of bringing the matter of an abscess to the skin; as also where ulceration begins upon a surface, or is increasing a sore. Whether the increase of pain arises from the ulcerative inflammation singly, or from the adhesive and ulcerative going on together in the same point, is not easily determined; but in some cases these three are pretty rapid in their progress, and it is more than probable that the pain arises from all these causes. In those cases where ulceration is employed in separating a dead part, such as sloughing, exfoliation, etc., it is seldom attended with pain ; perhaps it may not be easy to assign a cause for this. The effects that ulceration has upon the constitution I have mentioned, with the effects that other local complaints have upon it. It is easy to distinguish between a sore that is ulcerating, and one which is standing still, or granulating. The ulcerating sore is made up of little cavities or hollows, and the edge of the skin is scolloped or notched, is thin, turned a little out, and overhangs more or Jess the sore. The sore is always foul, being probably composed of parts not completely absorbed, and discharges a thin matter. But when the ulceration stops, the edge of the skin becomes regular, smooth, a little rounded or turned in, and of a purple colour, covered with a semitransparent white. 450 HUNTER ON THE BLOOD. § 6. Of the Relaxing Process.

Besides these two modes of removing whole parts, acting singly or together, there is an operation totally distinct from either, and this is a relaxing and elongating process carried on between the abscess and the skin, and at those parts only where the matter appears to point. It is possible that this relaxing, elongating, or weakening process may arise in some degree from the absorption of the interior parts ; but there is certainly something more, for the skin that covers an abscess is always looser than a part that gives way from mere mechanical distension, excepting the increase of the abscess is very rapid. That parts relax or elongate without mechanical force, but from particular stimuli, is evident in the female parts of generation just before the birth of the foetus: they become relaxed prior to any pressure. The old women in the country can tell when a hen is going to lay, from the parts becoming loose about the anus. That this relaxing process takes place between an abscess and the skin is evident in all cases, but was more demonstratively so in the following case than commonly can be observed, where an increase of surface takes place without the visible loss of substance, for here both could be exactly ascertained ; and, indeed, no abscess could swell outwards, excepting by distension, without it. In the following case this process was particularly evident. A lad about thirteen years of age wras attacked with a violent inflammation in his belly, without any apparent cause. The usual means were used, but without effect. His belly began to swell in a few days after the attack, and his skin became cold and clammy, especially his feet and hands. Once when he made water it was transparent like spring water, with a little cloud of mucus. In several places of the belly there appeared a pointing, as if from matter; one of those, which was just below the sternum, became pretty large, and discoloured with a red tint. Although there was not any undulation or perfect fluctuation (there not being fluid enough for such a feel) yet it was plain there was a fluid, and most probably from the pointings, it was matter in consequence of inflammation, and was producing ulceration on the inside of the abdomen for its exit; therefore it was thought advisable, as early as possible, to open the belly at one of those parts. I made a small opening into the pointing part, just below the sternum, hardly an inch long: when I was performing the operation, I saw plainly the head of the rectus muscle, which 1 cut through in the direction of its fibres. There was immediately discharged by this wound about two or three quarts of a thin, bloody matter. The swelling of the abdomen subsided of course; his pulse began to rise and become more full and soft; and his extremities became warmer; he was ordered bark, etc., but he lived only about sixty hours after the operation. THE ULCERATIVE INFLAMMATION. 451 On opening his abdomen after death we found little or no matter lying loose; all had made its escape through the wound. The whole intestines, stomach, and liver, were united by a very thick covering of the coagulating lymph, which also passed into all the interstices between them, by which means they were all united into one mass : the liver also adhered to the diaphragm, but none of the viscera adhered to the inside of the belly on its fore part, for there the matter had given the stimulus for ulceration, which prevents all adhesions. The process of ulceration had gone on so far as to have destroyed the whole, of the peritonaeum on the fore part ofthe abdomen, and the transversales and recti muscles were cleanly dissected on their inside. The tendons of the lateral muscles that pass behind the heads of the recti were in rags, partly gone, and partly in the form of a slough. From this view of the case we must see how Nature had guarded all the most essential parts. In the time of the adhesive stage she had covered all the intestines with a coat of coagulating lymph, so as to guard them ; and this probably upon two principles, one from their being canals, and therefore loth to admit of penetration in that way; the other from their being more internal than the parietes of the abdomen; one side is therefore thickened for their defence, while the other is thinned for the relief of the part. Here the cavity of the abdomen had assumed all the properties of an abscess, but it was so connected with the vital parts, which also suffered much in the inflammation, that the patient could not support the necessary processes towards what would be called a radical cure in many other parts; and indeed, considering the mischief done to the abdomen and its viscera, it is astonishing he lived so long. The most curious circumstance that happened was the appearance of pointing in several places; for why one part of the abdomen should have pointed more than another is not easily accounted for, since every part of the anterior portion was nearly equally thin, each part was equally involved in the abscess, and the ulceration had not yet begun with any of the muscles. To account for this, let us suppose that one, two, or three parts (by some accident) were more susceptible of the ulcerative stimulus than the others, and that the parts were ready to give way; but although these parts which were pointing were the places where ulceration would have gone on brisker, yet it had not proceeded further here than in any other part, it had only gone through the peritonaeum and the tendons ofthe broad muscles, and the recti muscles were sound and perfect at the place where I made the opening, which was the most protuberant of any; therefore this pointing did not appear to arise from weakness or thinness of this part; and even supposing that the pointing was an effect of weakness, it would imp y a great deal of pressure on the inside, (which at least was not the case here,) and simple pressure, although a hundred times greater, which we 452 HUNTER ON THE BLOOD. often see take place in dropsies, would not produce a pointing if not attended with some specific power.*

* [Having previously expressed my doubts as to the existence of any special law determining the course of foreign bodies to the surface (p. 2b9, note), I may here be permitted to express the same doubts respecting abscesses. "An internal pressure," Mr. Hunter observes, p. 441, " produced by an extraneous body, acts equally on every side ofthe surrounding parts, and therefore every part being pressed alike, ought, from this cause alone, to produce absorption of the surrounding parts equally on all sides," &c. A fallacy, however, is involved in this statement, arising from the omission of an important fact, viz., the resiliency or natural tonicity of the skin, which, being put still further on the stretch by the intrusion of a foreign body, reacts, so as to give a determinate direction to the force. In most cases this direction will be outwardly and inwardly, but inwardly the parts are not disposed to yield, and therefore in the same proportion as the external parts are more yielding than the internal, will there be an additional cause to determine the absorption in that direction; for I suppose it will not be doubted that extension and pressure are both powerful determining causes of inflammation and ulceration. With regard to abscesses, other mechanical causes of a tendency to the surface will come into operation besides the greater extensibility of parts in that direction. For by the bulging thus originally produced, the area ofthe upper surface of the cavity will be greater, even from the first, than that of the base: and as fluids under pressure act equally on equal areas, the whole amount of pressure outwards will be increased in proportion to the local augmentation of area. This preponderance of pressure must produce a greater degree of stretching and a more active ulcerative absorption here than elsewhere; and the cause in question will grow more and more effective as the prominence which it contributes to produce is augmented,—so that the pointing ofthe abscess will proceed with a constantly accelerated rapidity. These combined causes will manifestly be all in the fullest operation at the middle point of the outer surface of the cavity; A here the cavities will be most stretched, because the least supported; here the vital processes which produce attenuation will be most active because most stimulated ; and it is in this situation that, ceteris paribus, the prominence is always observed to be most considerable, and that the abscess naturally bursts. The annexed diagrams are intended to represent sections of an abscess in three several degrees of its progress towards the surface; and will serve to illustrate the suggestions that have been thrown out as to the causes ofthe outward tendency of the contained fluid. It will be seen that the surface of the cavity towards the skin (b, b b,b b b), progressively increases in area at a quicker rate than the base (a, a a, aaa). This view I think is confirmed by the erratic course of internal abscesses, which only burrow in those directions in which the extensibility is greatest, as well as by the case of peritoneal abscess cited in the text, and that of chronic abscesses generally ; for as the superfices of an abscess becomes more extended, and as the disposition to absorption becomes less active, so of course will the disposition to acuminatum become less evident. In dropsies both these causes combine to prevent pointing; for here there is no disposition to progressive absorption arising from CD THE ULCERATIVE INFLAMMATION. 453 If pressure then was not sufficient to produce this effect in the present case, and if the parts which pointed were as mechanically firm as at any other, to what other cause can we attribute the distension of this part, but to the weakening, elongating, and relaxing process which I have already described 1 This observation of the relaxing process going on in the substance of the parts where it points is verified in a thousand instances. Suppose a large abscess in the thigh, only covered by the skin and adipose membrane, which shall go on for months without producing ulceration, and of course not point anywhere, but shall be a smooth, even, and uniform surface; let it receive the stimulus of ulceration in any one part, that part will immediately begin to point, although it may be thicker there than at some other parts of the same abscess. The pressure necessary to allow extraneous matter to make its escape need not be great; for in many abscesses which have been opened, or have opened of themselves, but not at the most depending part, so that the matter is allowed to stagnate at the lower part of the cavity, making a very slight pressure, we find that this alone is sufficient to produce ulceration in that part, and of course a fresh opening is produced, more especially if near the skin. This we see often take place in abscesses of milk breasts, when the opening is not at a depending part, and appears to be common in the fistula in ano ; for it frequently happens that the ulceration goes on at first towards the gut; but before this has taken place, ulceration has gone on some way by the side of it, to bring the matter externally, which weight of matter is alone sufficient to continue the same process.

§ 7. Of the Intention of Absorption of the Body in Disease. This, like everything else in nature, involves in it two consequences, the one beneficial, the other hurtful, both of which this has in a considerable degree ; however, if we understood thoroughly all the remote causes, we should probably see its utility in every case, and that these effects, however bad in appearance, yet are necesinflammation, and no disposition to concentrate the acting force arising from inequality of extension. The discovery of final causes appears to have been a principal object in all Mr. Hunter's investigations, and it must be confessed that few have ever been equally successful in this branch of inquiry. It was, however, the weakness as well as the strength of Hunter's physiology, as it often led him to substitute the final for the efficient causes of phenomena, of which, if I am not mistaken, several examples might be adduced from the present chapter. As the above explanation is opposed to the received opinions of the profession, I offer it with much diffidence. As an instance of intelligent design, extending even to a provision for the accidental lesions ofthe frame, few examples are more beautiful than that ofthe adhesive inflammation, and especially ofthe approach of foreign bodies to the surface by progressive absorption; but nothing is detracted from the value of these facts by showing that mechanical causes are concerned in their operation.] 454 HUNTER ON THE BLOOD.

sary, and of course in the end salutary. The use arising from what may be called the natural absorption of parts, such as the forming or modelling process, as also the absorption of parts which have become unfit for the new mode of life, as the absorption of the thymus gland, &c, is involved in its necessity, and belongs to the natural history ofthe animal; but that arising from disease is directly to the present purpose. In the history I have just given, its use must, I apprehend, be evident; for we plainly see, in each mode of absorption, it often produces very salutary effects ; and we may say that, although it often arises from disease, yet its operations and effects are often not at all a disease; and probably in those cases where we cannot assign a cause, as in wasting of parts, atrophy, &c, yet it is most probable that its use is considerable. It is likely that under such a disease, or state of body or parts, it would be hurtful to have them full and strong; where it produces a total waste of a part its utility is probably not so evident; but in the progressive absorption, where it is leading bodies externally, or in consequence of suppuration, where it is bringing matter externally, its use is plain; or even in the formation of an ulcer, or the spreading of an ulcer, its use may be considerable. I have formerly called it the natural surgeon ; and where it can do its business it is in most cases preferable to art: this is so evident in many cases that it has been a constant practice to attempt to promote it in bringing abscesses to the surface, in the exfoliation of bone, &c, and although not accounted for upon the principle of absorption, yet the effect was visible, and its use allowed.

§ 8. The Modes of promoting Absorption.

The history that was given of the causes of absorption in some degree explains the modes of promoting it; but as there were some natural causes which we cannot imitate, it is principally those that can be rendered useful that we are to take notice of in this place. To promote absorption of the body itself is no difficult operation; it is only to lessen the supply and increase the waste, which last is often done by medicine, or to take such things as will render the supply less efficacious, as vinegar or soap; but probably these act principally on the fat. To promote absorption of diseased parts, or parts increased, or parts newly formed is not so easy a task, although the latter may be the most easy of the whole, for I have asserted that newly formed parts are weaker in their living powers than the originally formed parts. This in some degree gives us a hint; for if we hive a mode of producing a waste of the whole original body, under this general waste, new-formed parts must suffer in a degree proportional to their weakness, and therefore will suffer a diminution in the same proportion ; but this is too often not sufficient, or at least what would be sufficient for the disease would be too great for the constitution to bear; however, we find in particular cases that this practice has some effect. Probably the best THE ULCERATIVE INFLAMMATION. 455 debilitating medicine is mercury, and it probably may act in more ways than one. It may promote absorption from a peculiar stimulus, producing necessity, or a state under which the parts cannot exist. Electricity and most other stimulants probably act in the same manner, for we find that violent inflammation is often a cause. Death in a part is sure to promote absorption, in order to produce a separation of the dead parts ; and we even find that a part being diseased gives a tendency to separation, and only requires a considerable inflammation to promote it, such as warts coming away in consequence of inflammation. A diseased part has such power of giving the proper stimulus to the adjacent sound part, that if injured, or rendered dead in part by the application of a caustic for instance, the sound part underneath will begin to relax, and show more distinctly the limits or boundaries of the disease; so that a separation of the diseased parts begins to take place, although the caustic has not reached nearly so far, and may give us an intimation of the extent of the disease which we could not get before. It is in some measure upon this principle that arsenic removes tumours, which extend beyond the immediate effect ofthe medicine.* Pressure is one of the causes of absorption in general, particularly the progressive, which in the resolution of parts is not the mode wanted; but it also assists in producing the interstitial; and if it could be made to produce the second of the interstitial, viz., absorption of the whole, as in the total decay of the thymus gland, then it would be sufficient in those cases where it could be applied. But the pressure must be applied with great care, for too much will either thicken or ulcerate, which last may be a mode of absorption we do not want. However, these effects will happen according to circumstances; for I have an idea that entirely new-formed parts, as tumours, will not be made to thicken by pressure, and therefore may be pressed with all the force the natural surrounding parts will allow. On the other hand there are many cases where we would wish to prevent absorption; but when this is the case we should be certain that the part which was to have been absorbed is such as can be rendered useful afterwards, of which I have my doubts in many cases.

§ 9. Illustrations of Ulceration. Now that I have been endeavouring to give ideas of these effects of inflammation, viz., adhesion, suppuration, and ulceration, let me next mention some cases which frequently occur, as illustrations, which will give a perfect idea of these three inflammations; and, for the clearer understanding them, I shall illustrate them upon the inflammation, suppuration, and ulceration of the large circumscribed cavities. For instance, an inflam-

* [Yet as the irritation cannot fail but extend beyond the immediate effect, it is probable that these adventitious parts are thrown off in consequence of their not being able to support life under the inflammation which succeeds.] 456 HUNTER ON THE BLOOD. mation attacks the external coat of an intestine: the first stage of this inflammation produces adhesions between it and the peritonaeum lining the abdominal muscles; if the inflammation does not stop at this stage, an abscess is formed in the middle of these adhesions, and the matter acts as an extraneous body; the abscess increasing in size from the accumulation of matter, a mechanical pressure is kept up, which irritates, and the side next the skin is only susceptible of the irritation: this irritation not destroying the disposition to form matter, suppuration is still continued, and the ulcerative inflammation takes place. If suppuration began in more parts of the adhesions than one, they are commonly united into one abscess ; an absorption of the parts between the abscess and the skin takes place, and the matter is led on to the external surface of the body, where it is at last discharged. If the disposition for ulceration was equal on every side of the abscess, it must open into the intestine, which is seldom the case, although it sometimes does : for the same precautions are not taken here as in many other situations ; for in some others, as in the nose, in the case of an abscess ofthe lachrymal sac, the passage is thickened towards the nose. In the case above described, however, the abdominal muscles, fat, and skin, are removed, rather than the coats of the intestine. Cases of this kind have come under my own observation. In these cases if adhesions had not preceded ulceration, the matter must have been diffused over the whole cavity of the belly; if the adhesive inflammation had not likewise gone before the ulceration in the abdominal muscles, etc., the matter would have found a free passage from the abscess into the cellular membrane of the abdomen, as soon as the ulceration had got through the first adhesions, as is often the case in erysipelatous suppurations. Abscesses between the lungs and the pleura, in the liver, gallbladder, etc.,rise to the surface from the same cause; also in lumbar abscesses, where one would at first imagine the readiest place of opening would be the cavity of the abdomen, or gut; the parts nearest to the skin are removed, and the matter passes out that way; however, in abscesses so very deep, it does not always happen that one side only is susceptible of the irritation, and we shall find that the matter is taking different courses. Abscesses in the substance of the lungs sometimes differ from the above described, for they sometimes open into the air-cells: this occurs because the adhesive inflammation finds it difficult to unite the air-cells, and branches of the trachea, (as was described in treating of that inflammation,) and also because in the substance of the lungs, it may be difficult to say where it can take a lead externally, from which, probably, the air-cells become similar to art external surface, and then ulceration takes place on that side of the abscess which is nearest to the cells; therefore we find that the matter gets very readily into the air-cells, and from thence into the trachea. THE ULCERATIVE INFLAMMATION. 457 That the air-cells do not take on the adhesive state is evident in most abscesses in this part; for we find in most of these cases that the air-cells are exposed, as also the branches of the trachea; and the parts of the lungs which compose this abscess have not the firmness and solidity which the adhesive inflammation generally produces in those parts where it takes place. Thus, too, we find it going on in large abscesses, even after they have been opened, but are so situated or circumstanced as to have some part of the abscess on that side immediately under the skin pressed by some other part of the body which lies underneath. For instance, wmen a -large abscess forms on the outer and upper part of the thigh opposite the great trochanter, which is a very common complaint, and an opening is made into it, or it burst below or on the side of that bone, but not directly opposite to the trochanter itself, in such cases it frequently happens that the pressure of the trochanter on the inside of the abscess, viz., the cellular adipose membrane and the skin covering the trochanter, that this pressure produces ulceration of these parts : which process is continued on through the skin, and makes a second opening directly upon the trochanter. It is curious to remark how these processes of nature fulfil their appointed purposes, and go on no further; for any young flesh, or granulations, which may have formed upon the trochanter, which very often happens before this ulceration is completed, yet these do not ulcerate, although the pressure was as great or greater upon them than it was upon the parts which gave way. This is upon the principle that pressure from without has not the same effect as from within. The fistula lachrymalis is another strong proof of ulceration only taking place towards the external surface, and securing the deeper-seated parts; as also the ulceration in consequence of matter in the frontal sinuses. An effect of the same kind we have observed in milk-breasts. In these cases the suppuration commonly begins in many distinct portions of the inflamed parts, so that it is not one large circumscribed abscess, but many separate sinuses are formed, all of which generally communicate: now it usually happens, that only one of these points externally; which being either opened or allowed to break, the whole ofthe matter is to be discharged this way; but it frequently happens that the matter does not find a ready outlet by this opening, and then one or more of these different sinuses make distinct openings for themselves; which shows how very easily the slight pressure of such a trifling confinement of matter can produce the ulcerative inflammation. Ulceration is therefore no more than an operation of nature to remove parts out of the way of all such pressure as the parts cannot support; and accordingly it begins where the greatest pressure is felt, joined with the nature of the parts and its vicinitv to the skin. It is curious to observe that the ulcerative process has no power over the cuticle, so that when the matter has got to that part it 39* 458 HUNTER ON THE BLOOD. stops, and cannot make its way through till the cuticle bursts by distension; but in general the cuticle is so thin as to give but very little trouble;* however, in many places it is so thick as to be the cause of very troublesome consequences. Thus far I have considered ulceration as arising from visible irritations, joined with a susceptibility of the parts for such particular irritation; but besides those above described, we often have instances of ulceration taking place from a disposition in a part, and where perhaps no reason can be assigned but weakness in the part. I observed before, that some parts of the body were more susceptible of ulceration than others. I thei: spoke of original parts; but I now remark that newly-formed parts are much more susceptible of ulceration than the original; such as cicatrices, granulations, calluses, etc., for we find this disposition often taking place in old cicatrices from very slight causes, such as irregularity in the way of life or violent exercise, which is seen every day in our hospitals, where the parts seem incapable of supporting themselves. Remarkable instances of this are recorded in Anson's Voyages, where the habit was so much debilitated as to allow all the old sores to ulcerate, or break out anew : the calluses were absorbed and taken into the circulation; and we also find that all these parts perform

* This is the reason why many abscesses in the palms of the hands, soles of the feet, fore part ofthe fingers, and about the nails, commonly called whitloes, &c, more especially in working people, give so much pain in the time of inflammation, and are so long in breaking, even after the matter has got through the cutis to the cuticle; the thickness of the cuticle, as also the rigidity of the nail, acting in those cases like a tight bandage, which does not allow them to swell or give way to the extravasation; for in the cuticle there is not the relaxing power, which adds considerably to the pain arising from the inflammation ; but when the abscess has reached to this thick cuticle it has no power of irritation, and therefore acts only by distension; and this is in most cases so considerable, as to produce a separation ofthe cuticle from the cutis for a considerable way round the abscess; for I observed, when on inflammation, that it commonly produced a separation of the cuticle ; ail of which circumstances taken together, make these complaints much more painful than a similar-sized abscess in any other soft part. The application of poultices in these cases is of more benefit than in any other, because here they can act mechanically, viz., the moisture being imbibed by the cuticle, as in a sponge, and thereby softening the cuticle, by which means it becomes larger in its dimensions and less durable in its texture. These cases should be opened as soon as possible, to avoid the pain arising from distension and the separation of the cuticle; when it is conceived it means to point at any one part, paring off the thick cuticle near the cutis, allows the matter to make its escape more readily, when it has got through the cutis. There is a circumstance which almost always attends the opening such an abscess, viz., the parts underneath push out through the opening in the cuticle, like a fungus, which when irritated from any accident, gives a greater idea of soreness perhaps than any other morbid part of the machine ever does; this is owing to the surrounding belts of cuticle not having given way to the increase ofthe parts underneath, by which means they are squeezed out of this small opening, like paint out of a bladder. It is a common practice to eat this down by escharotics, as if it was a diseased fungus; but this additional pain is very unnecessary, as the destroying a part which has only escaped from pressure, cannot in the least affect that which is within; and by simply poulticing till the inflammation, and of course the tumefaction, subside, these protruded parts are gradually drawn into their original situations. GRANULATIONS. 459 the operation of sloughing when dead, much sooner than original parts. Now it is evident, in those cases mentioned in Anson's Voyages, that the whole frame of body was weakened by the hardships suffered in this expedition; and that the young or new-formed substances would suffer in a greater degree, arising from their being less firm and fixed than that which had been an original formation, and subsisted from the first; and as no repaired parts are endowed with the powers of action or resistance equal to an original part, it is no wonder that this new flesh, sharing in the general debility, became incapable of supporting its texture: perhaps a very sense of this debility proved an irritation, or the cause of that irritation which produced the absorption of parts; however that may be, it is a general fact that parts which are not originally formed, commonly give way soonest in depravations of the habit: in like circumstances also old sores that are healing, will break out, spread, and undo, in twenty-four hours, as much of the parts as had been healing in so many weeks. All these observations tend to prove that newformed parts are not able to resist the power of many diseases, and to support themselves under so many shocks, as parts originally formed; which will be still further illustrated in treating of the power of absorption. I observed that, although a part is losing ground or ulcerating, yet it continues suppurating ; for while a matter-forming surface is ulcerating, (whether an original-formed part of the body, such as most abscesses, or a new-formed substance, such as granulations,) we find that it still secretes pus. In such cases the adhesive inflammation proceeds very rapidly, and would seem to prepare the parts as it goes for immediate suppuration, the moment they are exposed. CHAPTER VII.

GRANULATIONS. We come now to trace the operations of Nature in bringing parts whose disposition, action, and structure, had been preternaturally altered, either by accident or diseased dispositions, as nearly as possible to their original state. In doing this we are to consider the constitution and the parts as free from disease, because all actions which tend to the restoration of parts are salutary, ihe animal powers being entirely employed in repairing the loss and the injury sustained both from the cause, and arising from the course of the immediate effects, viz., inflammation, suppuration, and ulceration: now such operations cannot certainly be looked upon as morbid. 460 HUNTER ON THE BLOOD. Nature having carried these operations for reparation so far as the formation of pus, she, in such cases, endeavours immediately to set about the next order of actions, which is the formation of new matter, upon such suppurating surfaces as naturally admit of it, viz., where there has been a breach of solids; so that we find following and going hand in hand with suppuration, the formation of new solids, which constitute the common surfaces of a sore. This process is called granulating, or incarnation; and the substance formed is called granulation. Granulations have, I believe, been generally supposed to be a consequence of, or always an attendant on, suppuration; but the formation of granulations is not confined to a breach of solids where the parts have been allowed to suppurate, either from accident or a breach of the solids in consequence of an abscess; but it takes place under other circumstances ; for instance, when the first and second bond of union has failed, as in simple fractures, which will be noticed hereafter. Suppuration, I observed, arose in consequence of an injury having been done to the solids, so as to prevent them for some time from carrying on their natural functions ; and I also observed that it was immaterial whether this injury had exposed their surfaces, as in cases of accidents and wounds, or whether the surfaces were not exposed, as in cases of abscesses in general; for in either of them suppuration would equally take place: I likewise observed that it was not necessary that there should be a breach in the continuity of parts for suppuration to take place in many cases, because all secreting surfaces were capable of suppuration; but this last seems not to be so commonly the case with granulations. I believe that no internal canal will granulate, in consequence of suppuration, except there has been a breach of surface, and then it is not the natural surface which granulates, but the cellular membrane, etc., as in other parts. Wounds that are kept exposed do not granulate till inflammation is over, and suppuration has fully taken place ;* for as the suppurative inflammation constantly follows, when wounds come to be under such circumstances, it would seem to be in such cases a leading and necessary process for disposing the vessels to granulation. Setting out then with the supposition that this inflammation is in general necessary, under the above circumstances, for disposing the vessels to form granulations, we shall at once see how it may operate in the same manner, whether it arises spontaneously from a wound, the laceration of parts, mortification, bruise, caustic, or in short any other power which destroys or exposes the innumerable internal cells or surfaces, so as to prevent their carrying on their natural functions. Few surfaces in consequence of abscesses granulate till they are

* [It is a singular circumstance that although exposure seems to be a necpssary condition for granulations to take place, yet subsequent seclusion seems to be equally necessary for their continuance, to effect which is one of the principal objects of all dressings.] GRANULATIONS. 461 exposed, so that few or no abscesses granulate till they are opened, either of themselves or by art; and therefore in an abscess, even of very long standing, we seldom if ever find granulations. In abscesses, after they have been opened, there is generally one surface that is more disposed to granulate than the others, which is the surface next to the centre of the body in which the suppuration took place. The surface next to the skin hardly ever has the disposition to granulate: indeed, before opening, its action was that of ulceration, the very reverse of the other; but even after opening, that side under the skin hardly granulates, or at least not readily. I may further observe, that exposure is so necessary to granulation, even on such surfaces as arise from a broken continuity of parts, that if the abscess is very deep-seated they will not granulate kindly without being freely exposed, which alone often becomes a cause why deep-seated abscesses do not heal so readily, and often become fistulous. Upon the same principle of granulations forming more readily upon that surface which is next to the centre, or opposite to the surface of the body, is to be considered their tendency to the skin. Granulations always tend to the skin, which is exactly similar to vegetation, for plants always grow from the centre of the earth towards the surface :* and this principle was taken notice of when we were treating of abscesses coming towards the skin.

§1.0/" Granulations independent of Suppuration.

The formation of granulations, I have observed, is not wholly confined to a breach made in the solids, either by external violence and exposure, or in consequence of a breach in the solids, which had been produced by suppuration and ulceration, and afterwards exposed ; for parts are capable of forming granulations, or what I suppose to be the same thing, new animal matter, where a breach has been made internally, and where it ought to have healed by the first intention ; but the parts being baulked in that operation, often do not reach so far as suppuration, so as to produce the most common cause of granulation. The first instance of the kind that gave me this idea was in a man who died in St. George's Hospital. January, 1777. A man about fifty years of age fell and broke his-thigh-bone nearly across, and about six inches above the lower end. He was taken into St. George's Hospital; the thigh was bound up, and put into splints, etc. The union between the two bones did not seem to take place in the usual time. He was taken ill with a complaint in his chest, which he had been subject to before, and died between three and four weeks after the accident. On examining the parts after death there were found little or no effects of inflammation in the soft parts surrounding the broken bones, except close to the bones where the adhesive inflammation * [See note, p. 277.] 462 HUNTER ON THE BLOOD. had taken place only in a small degree. The bones were found to ride considerably, viz., near three inches. The cavity made in the soft parts, in consequence of the laceration made by the riding of the bones, had its parietes thickened and pretty solid, by means of the adhesive inflammation, although not so much as would have been the case if the parts had been better disposed for inflammation; and some parts had become bony. There hardly was found within this cavity any extravasated blood or coagulating lymph, except a few pretty loose fibres like strings, which were visibly the remains of the extravasated blood. From these appearances this cavity had evidently lost its first bond of union, viz., the extravasated blood, which took place from the ruptured vessels; and probably the second had never taken place, viz., the coagulating lymph, in consequence of the adhesive inflammation: however, there was an attempt towards a union, for the surrounding soft parts, we have observed, had taken on the adhesive and ossific inflammation, so that in time there might have been formed in the surrounding soft parts a bony case, which would have united the two bones ; but the parts being deprived of the two common modes of union, they were led to a third. From the ends of the bones, and some parts of their surface, as well as from the inner surface of the soft parts, there was formed new flesh, similar to granulations. The hollow ends of the bones were filled with this matter, which was rising beyond the common surface of the bone, and in some places adhesion had taken place between it and the surrounding parts, with which it had come in contact. The same appearance which this new flesh had in this case I have several times seen in joints, both on the ends of the bones and on the inside of the capsular ligament, but never before understood how it was formed; hence we find that granulations can and do arise in parts that are not exposed. This is what I have long suspected to be the case in the union of the fractured patella, and this fact confirms me more in that opinion.* Here then we are shown that the cause of granulation, or the forming of new flesh for union (independently of extravasation, or the adhesive inflammation), is more extensive in its effects than we were formerly acquainted with, and that granulations, or new flesh, arise in all cases from the first and second bond of union being lost in a part (which indeed seldom happens,except from exposure); it therefore makes no difference whether the first and second bond of union escape through an opening made in the skin, as in a compound fracture, or it loses its living powers, as in the present case, and as I suppose to be the case in a fracture of the patella, which obliges the absorbents to take it up as an extraneous body.

* [This opinion has not been confirmed by any subsequent and more unequivocal proofs, and therefore it is now generally considered to be erroneous.] GRANULATIONS. 463 § 2. The Nature and Properties of Granulations. Granulations and this new-formed substance are an accretion of animal matter upon the wounded or exposed surface: they are formed by an exudation of the coagulating lymph from the vessels, into which new substance both the old vessels very probably extend, and also entirely new ones form, so that the granulations come to be very vascular, and indeed they are more so than almost any other animal substance. That this is the case is seen in sores every day. I have often been able to trace the growth and vascularity of this new substance. I have seen upon a sore a white substance, exactly similar in every visible respect to coagulating lymph. I have not attempted to wipe it off, and the next day of dressing I have found this very substance vascular, for by wiping or touching it with a probe it has bled freely. I have observed the same appearance on the surface of a bone that has been laid bare. I once scraped off some of the external surface of a bone of the foot, to see if the surface would granulate. I remarked the following day that the surface of the bone was covered with a whitish substance, having a tinge of blue; when I passed my probe into it I did not feel the bone bare, but only its resistance. I conceived this substance to be coagulating lymph, thrown out from inflammation, and that it would be forced off when suppuration came on ; but on the succeeding day I found it vascular, and appearing like healthy granulations. The vessels of granulations pass from the original parts, whatever these are, to the basis of the granulations; from thence towards their external surface, in pretty regular parallel lines, and would almost appear to terminate there. The surface of this new substance, or granulations, continues to have the same disposition for the secretion of pus as the parts from which they were produced ; it is therefore reasonable to suppose that the nature of the vessels does not alter by forming the granulations, but that they were completely changed for the purpose before the granulations began to form, and that these granulations are a consequence of a change then produced upon them. Their surfaces are very convex, the reverse of ulceration, having a great many points or small eminences, so as to appear rough; and the smaller'these points are, the more healthywe find the gra-

""ThTcolour of healthy granulations is a deep florid red, which would make us suspect that the colour was P™ipa"y owing to the arterial blood,* but it only shows a brisk circulation in them, the blood not having time to become dark.

* t u „„ *„ c,ianPf-t that the air might have some influence upon the blood

the legs by standing erect, I gave up that idea. 464 HUNTER ON THE BLOOD. When naturally of a livid red they are commonly unhealthy, and show a languid circulation, which appearance often comes on in granulations of the limbs from the position of the body, as is evident from the following case. A stout, healthy young man had his leg considerably .torn, and it formed a broad sore; when healing, it was some days of a florid red, and on others of a purple hue: wondering what this could be owing to, he told me when he stood for a few minutes it always changed from the scarlet to the modena. I made him stand up, and found it soon changed; this plainly showed that these new-formed vessels were not able to support the increased column of blood, and to act upon it, which proves that a stagnation of blood was produced sufficient to allow of the change in the colour, and most probably both in the arteries and veins. These sores never heal so fast as the others, whether it is occasioned by the position of the body or the nature of the sore itself; but most frequently so in cases of the last-mentioned kind. As the position of the body is capable of producing such an effect, it shows us the reason why sore legs are so backward in healing when the person is allowed to stand or walk. Granulations when healthy, and on an exposed or flat surface, rise nearly even with the surface of the surrounding skin, and often a little higher, and in this state they are always of a florid red: but when they exceed this, and take on a growing disposition, they are then unhealthy, become soft and spongy, and without any disposition to skin. Granulations are always of the same disposition with the parts upon which they are formed, and take on the same mode of action: if it is a diseased part, they are diseased ; and if the disease is of any specific kind, they are also of the same kind, and of course produce matter ofthe same kind, which I observed when on pus. Granulations have the disposition to unite with one another when sound or healthy ; the great intention of which is to produce the union of parts, somewhat similar to that by the first intention, or the adhesive inflammation, although possibly not by the same means. The granulations having a disposition to unite with each other upon coming into contact, without the appearance of any intermediate animal substance, perhaps is in the following manner. When two sound granulations approach together, the mouths of the secreting vessels of the one coming to oppose the mouths of similar vessels of the other, they are stimulated into action, which is mutual; so that a kind of sympathetic attraction takes place, and, as they are solids, the attraction of cohesion is established between them ; this has been termed inosculation. The vessels thus joined are altered from secreting to circulating; or it may be in this way, viz., the circulatory vessels come to open upon the surface, and there unite with one another, and the two become one substance; or it may be asked, do they throw out coagulating lymph when they come into contact and have a disposition to heal ? and does this become GRANULATIONS. 465 vascular, in which the vessels may inosculate, similar to union by the first or second intention 1 * I have seen two granulations on the head, viz., one from the dura mater after trepanning and the other from the scalp, unite over the bare bone which was between them so strongly, in twenty-four hours, that they required some force to separate them, and when separated, they bled. The inner surface of the cutis in an abscess or sore does not only not readily granulate, as has been mentioned, but it does not readily unite with the granulations underneath. The final intention of both seems to be that the mouth of a sore, which is seldom so much in a diseased state, should have a natural principle which attends disease, to put it upon a footing with the disease which is underneath ;f therefore when abscesses are allowed to become as thin as possible before they are opened, this proportion between the sound skin and the disease is better preserved, and the parts are not so apt to turn fistulous. When the parts are unsound, and of course the granulations formed upon them unsound, we have not this disposition for union, but a smooth surface is formed, somewhat similar to many natural internal surfaces of the body, and such as have no tendency to granulate, which continues to secrete a matter expressive ot tne sore which it lubricates, and in some measure prevents the union of the granulations. I imagine, for instance, that the internal surface of a fistulous ulcer is in some degree similar to the inner surface ofthe urethra, when it is forming the discharge commonly called a gleet. Such sores have therefore no disposition in tneir granulations to unite, and nothing can produce a union between fhem but altering the disposition of these granulations by exciting a considerable inflammation, and probably ulceration, so as to form new granulations, and by these means give them a chance of falling

^SLT.re not endowed with the same powers as parts orio-inally formed. In this respect they are similar to all new- S p'arts, and it is from this cause that c anges fj^ ™™ are so easily effected; they more readily fall into ulceration ana mortrficationythan originally-formed parts,, and from their readiness to ulcerate they separate sloughs more qujcUy. The granulations not on y show the state of the part in wnicn thev aregformed, or the state in which they are themselves, but they

* [This seems to be the most probable as well as most prevailing opinion at the present day.] o. „Mq :s freauentlv observed to extend, by a continuf [As the aperture of «J atacj- s ££»enJ that the bottom of the abscess is ance of the ulcerative ac ion at the same ^^ ^^ geem tQ be tQ filling °P ^^.Ki'SSr; but this meaning is probably included in the language ofthe author.] 4Q 466 HUNTER ON THE BLOOD. of the constitution are, I believe, the indolent and irritable habits, but principally fevers; and these must be such as to produce universal irritation in the constitution. The unsound appearances of the granulations show to what a stand the animal powers are put on such occasions, which does not appear so visibly in the originally-formed parts; it is therefore evident that the powers of the granulations are much weaker than those of the original parts.

§ 3. Longevity of Granulations. Granulations are not only weaker in performing the natural or common functions of the parts to which they belong, but they would appear often to be formed with only stated periods of life, and those much shorter than the life of the part on which they are formed. This is most remarkable in the extremities; but where they are capable of going through all their operations, as cicatrization, their life then seems to be not so limited, they are probably then acquiring new life, or longevity, every day. But while in a state of granulation we find them often dying without any visible cause. Thus a person shall have a sore upon the leg which shall granulate readily; the granulations shall appear healthy, the skin shall be forming round the edges, and all shall be promising well, when all at once the granulations shall become livid, lose their life, and immediately slough off; or, in some cases, ulceration shall in part take place, and both together shall destroy the granulations; and probably where ulceration wholly takes place it may be owing to the same cause. New granulations shall immediately rise as before, and go through the same process; this shall happen three or four times in the same person, and probably for ever, if some alteration in the nature of the parts be not produced. This circumstance ofthe difference in longevity of granulations in different people, is somewhat similar to the difference in longevity of different animals. In cases of short-lived granulations I have tried various modes of treatment, both local and constitutional, to render the life of these granulations longer, but without success. It would appear from what has been said of suppuration and granulation, that it is absolutely necessary they should take place in wounds which are not allowed to unite by the first intention, before union and cicatrization can take place. Although this in general is the case, yet in small wounds, such as considerable scratches, or where there is a piece of skin rubbed off, we find that by the blood being suffered to coagulate upon the sore and form a scab, which is allowed to remain, the sore will only be attended by the adhesive inflammation, and will skin over without ever suppurating. Where a small caustic has been applied we find also, by allowing the slough to dry or scab, that when this is completed the scab will drop off and the parts shall be skinned; but if the blood has not been allowed to coagulate and dry, or the slough has GRANULATIONS. 467 been kept moist, the sore will suppurate and granulate. We even see in small sores,* which are perfectly healthy and suppurating, that if the matter be allowed to dry upon them, the suppuration will stop, and the skin form under the scab: the small-pox is a striking proof of this, which was fully treated of in a former part ofthe work. A blister whose cuticle is not removed is similar to a scab, it does not allow of suppuration. If a separation takes place between the cutis and cuticle, and the cuticle be not removed, nothing will be collected through the whole course, and a new cuticle will be formed; but if the cuticle be removed, a greater degree of inflammation will come on, and suppuration will certainly take place.

§ 4. Ofthe Contraction of Granulations. Immediately upon the formation of the granulations, cicatrization would appear to be in view. The parts which had receded, in consequence of a breach being made in them, by their natural elasticity and probably by muscular contraction, now begin to be brought together by this new substance; and it being endowed with such properties, they soon begin to contract, which is a sign that cicatrization is to follow. The contraction takes place in every point, but principally from edge to edge, which brings the circumference of the sore towards the centre; so that the sore becomes smaller, although there is little or no new skin formed. The contracting tendency is in some degree proportioned to the general healing disposition of the sore, and the looseness ofthe parts on which it is formed; for when it has not a tendency to skin, the granulations do not so readily contract, and therefore contracting and skinning are probably effects of one cause. The granulations too, being formed upon a pretty fixed surface, which is a consequence of [the induration arising from] inflammation, are in some degree retarded in their contraction from this cause; but probably this does not act so much upon a mechanical principle as we at first might imagine, for such a state of parts in some degree lessens the disposition for this process; but this state is every day altering in proportion as the tumefaction subsides. Granulations are also retarded in their contraction from a mechanical cause, when they are formed on parts naturally fixed, such as bone; for instance, the skull, the bone of the shin, &c, for there the granulations cannot greatly contract.f In cases where there has been a loss of substance, making a hollow sore, and the contraction has begun and advanced pretty far before the granulations have had time to rise as high as the skin, in such cases the edges ofthe skin are generally drawn down and tucked in by it, in the hollow direction ofthe surface ofthe sore.

* [See p. 255, note.] . , t This observation should direct us, in operations on those parts, to save as much skin as possible. 468 HUNTER ON THE BLOOD. If it is a cavity or abscess which is granulating, with only a small opening, as in many that have not been freely opened, the whole circumference contracts, like the bladder of urine, till little or no cavity is left; and if any cavity is remaining when they cannot contract any further, they unite with the opposite granulations in the manner above described. This contraction in the granulations continues till the whole is healed, or skinned over; but their greatest power is at the beginning, at least their greatest effect is at the beginning, one cause of which is that the resistance to their contraction in the surrounding parts is then least. The contractile power can be assisted by art, which is a further proof that there is a resistance to be overcome. The art generally made use of is that of bandages, which tend to push, draw, or keep the skin near to the sore which is healing; but this assistance need not be given, or is at least not so necessary, till the granulations are formed, and the contractile power has taken place: however, it may not be amiss to practice it from the very beginning, as by bringing the parts near to their natural position the adhesive inflammation will fix them there; they will therefore not recede so much afterwards, and there will be less necessity for the contractile powers of the granulations. Besides the contractile powers of the granulations, there is also a similar power in the surrounding edge of the cicatrizing skin, which assists the contraction of the granulations, and is generally more considerable than that of the granulations themselves, drawing the mouth of the wound together like a purse; this is frequently so great as to occasion the skin to grasp the granulations which rise above the surface, and is very visible in sugar-loaf stumps, where the projection of the sore is to be considered as above the level of the skin. This contractile power of the skin is confined principally to the very edge where it is cicatrizing, and I believe is in those very granulations which have already cicatrized ; for the natural or original skin surrounding this edge does not contract, or at least not nearly so much, as appears by its being thrown into folds and plaits, while the new skin is smooth and shining. This circumstance of the original surrounding skin not having the power of contraction, makes round wounds longer in healing than long ones, for it is much easier for the granulations and the edge of the skin to bring the sides of an oblong cavity together, than the sides of a circle, the circumference of a circle not being so capable of being brought to a point. Whether this contraction of the granulations is owing to an approximation of all the parts by their muscular contraction, like that of a worm, while they lose in substance as they contract, or whether they.lose without any muscular contraction, by the particles being absorbed, so as to form interstices (which I have called interstitial absorption), and the sides afterwards fall together, is not exactly determined, and perhaps both take place. GRANULATIONS. 469 The uses arising from the contraction of the granulations are various. It facilitates the healing of a sore, as there are two operations going on at the same time, viz., contraction and skinning. It avoids the formation of much new skin, an effect very evident in .all sores which are healed, especially in sound parts. In amputation of a thick thigh (which is naturally seven, eight, or more inches in diameter before the operation), the surface of the sore is of the same diameter, for the receding of the skin here does not increase its surface, as it does in a cut on a plane; yet in this case the cicatrix shall be no broader than a crown-piece. This can be effected by the contractile power ofthe granulations, for it is bringing the skin within its natural bounds. The advantage arising from this is very evident, for it is with the skin as it is with all other parts of the body, viz., that those parts which were originally formed are much fitter for the purposes of life than those that are newly formed, and not nearly so liable to ulceration. After the whole is skinned we find that the substance, which is the remains of the granulations on which the new skin is formed, still continues to contract, till hardly anything more is left than what the new skin stands upon. This is a very small part in comparison with the first-formed granulations, and it in time loses most of its apparent vessels, becomes white, and ligamentous. For we may observe that all new-healed sores are redder than the common skin, but in time they become much whiter. As the granulations contract the surrounding old skin is stretched, to cover the part which had been deprived of skin, and this is at first little more than bringing the skin to its old position, which had receded when the breach was first made; but afterwards it becomes considerably more, so as to stretch, or oblige the old skin to elongate, from which we might ask the following question : Does the surrounding skin in the healing of a sore lengthen by growth, or does it lengthen by stretching only 1 I think that the former is most probable; and if this is the case I should call this process interstitial growth, similar to the growth of the ears of the people in the Eastern islands, particularly as it is an opposite effect to interstitial absorption. Granulations appear to have other powers of action besides simply their ceconomy tending to a cure. They have power of action in the whole, so as to produce other operations, and even to affect other matter. I conceive that a deep wound, such as a gunshot wound, advanced to suppuration and granulation, and also a fistula, become in some degree similar to an excretory duct, having the powers of a peristaltic motion from the bottom towards the opening externally. Thus we find that whatever extraneous body is situated at the bottom of the sore, is by degrees conducted to the skin, although the bottom ofthe sore or fistula is of the same depth. This effect in such sores does not arise from the granulations forming at the bottom, and gradually raising the extraneous body as ° 40* 470 HUNTER ON THE BLOOD. they form (which is commonly the case with exfoliations and sloughs), but we find extraneous bodies come to the skin when the bottom of the wound is not granulating.* CHAPTER VIII.

When a sore begins to heal we find that the surrounding old skin close to the granulations (which had been in a state of inflammation, having probably a red, shining surface, as if excoriated, and rather ragged), now becomes smooth and rounded, with a whitish cast, as if covered with something white, and the nearer to the cicatrizing edge the more white it is. This is, I believe, a beginning cuticle, and this appearance is probably as early a symptom of healing, and as much to be depended upon, as any; so that the disposition in the granulations for healing is manifested in the surrounding skin; and while the sore retains its red edge all round, for perhaps a quarter or half of an inch in breadth, we may be certain it is not a healing sore, and is what may be called an irritable sore. Skin is a very different substance, with respect to texture, from the granulations upon which it is formed, but whether it is an addition of new matter, viz., a new-formed substance upon the granulations, being pfoduced by them, or a change in the surface of the granulations themselves, is not easily determined. In either case, however, a change must take place in the disposition of the vessels, either to alter the structure of the granulations, or to form new parts upon them. One would at first be inclined to the former of these opinions, as we have a clearer idea of the formation of a new substance than such an alteration in the old. We find the new skin most commonly taking its rise from the surrounding old skin, as if elongated from it, but this is not always the case. In very large sores, but principally old ulcers, where the edges ofthe surrounding skin have but little tendency to contract, or the cellular membrane underneath to yield, as well as the old skin having but little disposition to skinning in itself, a cicatrizing disposition cannot be communicated from it to the nearest granulations by continued sympathy. In such cases new skin forms in different parts ofthe ulcer, standing on the surface of the granula-

* [This effect is rather to be attributed to the gradual contraction ofthe fistula from the bottom, which may therefore be represented by an inverted cone. The ascent of fluids against the force of gravity, as of the semen along the Fallopian tubes, the secretion ofthe lungs along the surface of the trachea, &c, is probably referrible in many instances to the actions of vibratory cilia, with which, according to recent discovery, the mucous membranes are found to be abundantly provided.] OF SKINNING. 47] tions like little islands. This, I believe, never takes place in parts the first time of their being sore, nor in sores which have a strong propensity to skin. Skinning is somewhat like crystallization, it requires a surface to shoot from, and the edge of the skin all round would appear to be this surface. Whatever change the granulations undergo to form skin, they may in general be said to be guided to it by the surrounding skin, which gives this disposition to the surface of the adjoining granulations, as adjacent bones give an ossifying disposition to the granulations that are formed upon them. This may arise from sympathy ; and if it does I should call it continued sympathy. But when the old skin is unsound, and not able to communicate this disposition, then the granulations sometimes of themselves acquire it, and new skin begins to form where that disposition is strongest in them, so that the granulations may be ready to form new skin, if the surrounding skin be not in a condition to give the disposition. It would appear,°however, that the circumference of the sore generally has the strongest disposition to skin, even although the surrounding skin does not assist, for in many old sores no new skin shall shoot from the surrounding skin, or 'be continued, as it were, from the old, and yet a circle of new skin shall form, making a circle within the'old, and as it were, detached from it. Skinning is a process in which Nature is always a great oeconomist, without a single exception; this, however, may probably arise from the granulations being always of the nature of the parts on which they are formed, and from seldom being formed on parts that are the least of the nature of the skin; they have therefore no strong disposition to form skin. What would seem to make this observation more probable is, that if the cutis is only in part destroyed, as by a hurt or caustic which has not gone quite through the cutis to the cellular membrane underneath, a new cutis will form immediately on the granulations, and in many cases it will form as fast as the slouo-h will separate; the reason is, because the cutis has a stronger tendency to form cutis than any other part, and in many cases it may be said to form it from almost every point. We never find that the new-formed skin is so large as the sore was on which it is formed; this, I have already observed, is brouo-ht about by the contraction of the granulations, which in some measme is in proportion to the quantity of surrounding old skin, attended with the least resistance. If the sore is in a part where rWou^ding skin is loose, as in the scrotum, then the contractile power of the granulations being not at all prevented, but allowed fuTscope, a ve^ry little new skin is formed ; whereas 1 the sore is on anv other part where the skin is not loose, such as the scalp, shinbone &c in hit case the new skin is nearly as large as the sore. This'we find to be the case also in parts which are so swelled as to render the skin tight, such as the scrotum, when under the disten- • ! hvrWele and which sometimes happens where a caustic haTprove/tffeSual; we then find the new skin as extensive as in any other parts equally distended. The same th.ng takes place 472 HUNTER ON THE BLOOD. in white swellings of the joint ofthe knee; for if a sore is made upon such a part, as is frequently done by the application of caustics, we find that the new skin is nearly of the same size as the original sore. The general principle is also very observable after amputations of the limbs: for if much old skin has been saved we find the cicatrix small; while, on the other hand, if such care has not been taken, the cicatrix is proportionably large. The new skin is at first commonly on the same level with the old, and if there has not been much loss of substance, or the disease is not very deep-sealed, it continues its position; but this does not appear to be the case with scalds and burns, for they frequently heal with a cicatrix higher than the skin, although the granulations have been kept even with skin. It would appear in these cases that a tumefaction of the parts, which were the granulations, takes place after cicatrization. Sometimes granulations cicatrize while higher than the common surrounding skin, but then they are such as have been long in that position, as is the case in some issues. I have seen the granulations surrounding a pea rise considerably above the skin, near half-acrown in breadth, and skin over, all but the hole in which the pea lay. the whole looking like a tumour.

§ 1. The Nature of the new Cutis.

The new-formed cutis is neither so yielding nor so elastic as the original is, and is also less moveable upon the part to which it is attached, or upon which it is formed. This last circumstance is owing to its basis being granulations, which are in some degree fixed upon parts united by the adhesive inflammation; and more particularly so when the granulations arise from a fixed part, such as a bone, the new skin formed upon them being also fixed in proportion. It is, however, constantly becoming more and more flexible in itself, and likewise more loosely attached, owing to the mechanical motion to which the parts are subject afterwards. The more flexible and loose the parts become, it is so much the better, as flexibility, or the yielding of the parts, preserves it from the effects of many accidents. Parts which have been thickened in consequence of inflammation, such as the surrounding parts of new skin, have always a less internal power of action in them than parts which have never been inflamed. This arises from the adventitious substance thrown out in the time of inflammation being a clog upon the operations of the original; and the new matter not being endowed with the same powers, the part affected, taken as a whole, is by these means considerably weakened. Motion given to the part so affected must be mechanical; but motion becomes a stimulant to the parts moved, that they cannot exist under such motion without adapting the structure ofthe parts to -it, and this sets the absorbents to work, or they receive the stimulus of necessity, and absorb all the adventitious or rather OF SKINNING. 473 superfluous substance; by which means the parts are as much as possible reduced to their original texture. Medicines have not the powers we could wish in many such cases : mercury, however, appears to have the power of producing a stimulus similar to motion, and should be made use of where a mechanical stimulus cannot be applied ; and I believe, when joined with camphor, its powers of producing absorption are increased: when both medical and mechanical means can be used, so much the more benefit will ensue. When everything else fails, electricity might be tried. It has been the cause of absorption of tumours. It has reduced the swellings of many joints in consequence of sprains, and thereby allowed of the freedom of motion. The new-formed cutis is at first very thin and extremely tender, but afterwards becomes firmer and thicker: it is a smooth continued skin, not formed with those insensible indentations which are observed in the natural or original skin, and by which the original admits of any distension the cellular membrane will allow of, as is experienced in many dropsies, white swellings in the joints, &c. This is proved by steeping a piece of dead skin, with a cicatrix in it, in water, to make the cuticle separate from the cutis; there we find that the new-formed cuticle becomes but little larger by such a process, which plainly shows that the new-formed cutis upon which this cuticle was* formed, has a pretty smooth continued surface, and not that soft unequal surface which distinguishes the original cutis. This new cutis, and indeed all the substance which had been formerly granulations, is not nearly so strong, nor endowed with such lasting and proper actions, as the originally-formed parts. The living principle itself is also not nearly so active; for when an old sore once breaks out, it continues to yield till almost the whole of the new-formed matter has been absorbed or mortified, as has been already explained. The young cutis is extremely full of vessels, which afterwards, in a great measure; either become lymphatic or impervious, or are taken into the constitution, so that the skin and granulations underneath are at last free from visible vessels, and become white. The surrounding original cutis, being drawn towards a centre by the contraction of granulations, to avoid as much as possible the formation of new skin, is thrown into loose folds, while the new looks like a piece of skin upon the stretch, and the whole appears as if a piece of skin had been sewed into a hole by much too large for it; and therefore it had been necessary to throw the surrounding old skin into folds, or gather the surrounding skin, in order to bring it in contact with the new. The new cutis of a sore I believe, never acquires a muscular structure; nor does it grow larger than the sore which it covers, so as to be thrown into wrinkles similar to the old, and therefore has always that stretched, shining appearance. 474 HUNTER ON THE BLOOD. § 2. Ofthe new Cuticle.

It does not appear to be so difficult a process for the cutis to form cuticle as it is for the granulations to form cutis; for we find in general, that wherever there is a new cutis formed, it is covered with a cuticle: and in cases of blisters, or any other cause which may have deprived the cutis of its cuticle, we find that the cuticle is soon restored. We are to observe, however, that in such cases it is a sound original cutis, forming its own cuticle, and having the whole power of forming the cuticle, the surrounding cuticle itself having no power of action of this kind : every point of cutis is forming cuticle, so that it is forming equally everywhere at once; whereas I observed that the formation of the cutis, was principally progressive from the surrounding cutis. • It is at first very thin, and partakes more of a pulpy than a horny substance; as it gets stronger, it becomes smooth and shining, and is much more transparent than original cuticle, which shows more the colour of the rete mucosum. This account relates to the cuticle of sound parts which had gone through all the operations of health; but where there is a retardation in the healing we find that the cuticle is in some cases backward in forming, and in others it shall be formed very thick, so as to make it necessary to be removed, it appearing to be a clog upon the cutis, retarding the progress of its formation.

The rete mucosum is later in forming than the cuticle, and in some cases never forms at all: this is best known in blacks who have been either wounded or blistered, for the cicatrix in the black is a considerable time before it becomes dark; and in one black who came under my observation, a sore which had been upon his leg when young, remained white when he was old. After blisters, too, the part blistered remains white for some time after the cuticle is completely formed: however, in many cicatrices of blacks we find them even darker than any other part of the skin. CHAPTER IX.

EFFECTS OF INFLAMMATION, AND ITS CONSEQUENCES ON THE CONSTITUTION.

The constitutional affections arising from inflammation are immediate and remote. The immediate affections have been already considered, viz., the sympathetic fever, and also the nervous. I shall now treat of EFFECTS OF INFLAMMATION, ETC. 475 the remote, viz., the hectic, and dissolution, which arise from the state of the local affection at the time; the inflammation not being able to go through all the salutary steps that have been described. We have diseases, however, sometimes accompanying those salutary processes; although we should naturally conclude from the foregoing account, that the suppurative inflammation, and suppuration itself, should produce no change in the constitution but what was attendant upon the inflammation, and might be supposed perhaps somewhat necessary to it; and that when inflammation had subsided, and a kind suppuration come on, the constitution should be left in a sound state, because it would now appear that all the future processes were settled; and [therefore that] a constitution that was capable of doing this, was also capable of going through all the succeeding operations, as they are only actions of restoration; but we find sometimes the contrary, and the condition in which the constitution is either left, or which it afterwards takes on, proves often much more hurtful than the inflammation itself. It appears in many cases that the inflammation, the attendant fever, the going off of these, and the commencement and continuance of the suppuration produce in many persons a change in the constitution, giving a disposition to symptoms which are called nervous. The locked jaw is often the effect of this leading cause, as well as hysterics, spasms upon the muscles of respiration, and great restlessness, which often prove fatal to the patient; there are likewise signs of great and universal debility or signs of dissolution in the patient, all of which appear to be increased by a continuance of the suppuration. Each of these diseases is well marked; and it would appear that the locked jaw, hysterics, spasms, and great restlessness are of the nervous kind,, and do not appear to arise from such a constitution as is not equal to overcome the cause, for the cause which produced them being removed, the effects are going on towards health now as well as before; and if the patient dies of any of those diseases, it is not from the cause, nor from the immediate effect, viz.. the local disease, but from the effect which the preceding operations, joined with the healing, have on some constitutions.0 They all seem to derive their origin from the same root, viz., from all the foregoing processes, which we have been describing; but they are altogether too extensive for our present subject.

I have now described the injuries of which inflammation is a consequence ; the progress of that action in different parts ; its effects on the constitution ; together with the mode of treatment of both, and have carried it through its various steps to a perfect restoration I have also already mentioned that the act of absorption affects some constitutions; but I shall now take notice that nature 476 HUNTER ON THE BLOOD. is not always equal to those salutary processes, and hence the constitution sometimes becomes particularly affected, producing symptoms different from those formerly described, and which have been called the hectic. This disease is one of our remote constitutional sympathetic affections, and appears to arise from a very different origin from the other sympathizing effects before mentioned. When it is a consequence of a local disease, it has commonly been preceded by the first process of the former, viz., inflammation and suppuration, but has not been able to accomplish granulation and cicatrization, so as to complete the cure. It may be said to be a constitution now become affected with a local disease or irritation, which the constitution is conscious of, and of which it cannot relieve itself, and cannot cure; for while the inflammation lasts, which is only preparatory, and an immediate effect of most injuries, and in parts which can only affect the constitution, so as to call up its powers, there can be no hectic. We should distinguish well between a hectic arising from a local complaint entirely, where the constitution is good, but only disturbed by too great an irritation ; and a hectic arising principally from the badness of the constitution, which does not dispose the parts for a healing state; for in the first, it is only necessary to remove the part (if removable) and then all will do well; but in the other we gain nothing by a removal, except the wound made by the operation is much less, and much more easily put into a local method of cure; so that this bad constitution falls less under this (the operation taken into the account) than under the former state; but all this depends on nice discrimination. The hectic comes on at very different periods after the inflammation, and commencement of suppuration, owing to a variety of circumstances. First, some constitutions much more easilyfall into this state than others, having less powers of resistance. The quantity of incurable disease must be such as can effect the constitution, and in whatever situation or in whatever parts, it will be always as to the quantity of disease in those situations or parts in the constitution, which will make the time to vary very considerably. In many diseases it would appear that the manner of coming on retards the commencement of the hectic, such as lumbar abscesses. But when such abscesses are put into that state in which the constitution is to make its efforts towards a cure, but is not equal to the task, then the hectic commences. It takes its rise from a variety of causes, but which I shall divide into two species, with regard to diseased parts, viz., the parts vital and the parts not vital. The only difference between these two is probably merely in time, with respect to its coming on, and its progress when come on : but what is very similar to the disease of a vital part, is quantity of incurable disease. The causes of hectic, arising from diseases of the vital parts, may EFFECTS OF INFLAMMATION, ETC. 477 be many, of which a great proportion would not produce the hectic if they were in any other part of the body ; such, for instance, as the formation of tumours, either in, or so as to press upon some vital part, or a part whose functions are immediately connected with life. Scirrhi in the stomach or mesenteric glands,, which tumours anywhere else would not produce the hectic; many complaints too of vital parts, as diseased lungs, liver, etc., all of these produce the hectic, and much sooner than if the parts were not vital. In many cases where those causes of the hectic come on quickly, it frequently follows so quick upon the sympathetic fever that the one seems to run into the other: this I have often seen in the lumbar abscess. They also produce symptoms according to the nature ofthe part injured, as coughs, when in the lungs; sickness and vomiting when in the stomach; and probably bring on many other complaints, as dropsies, jaundice, etc., but which are not peculiar to the hectic. When the hectic arises from a disease in a part not vital, it sooner or later commences, according as it is in the power of the parts to heal, or continue the disease. If far from the source of the circulation, with the same quantity of disease, it will come on sooner. When in parts not vital, it is generally in those parts where so great a quantity of disease can take place (without the power of being diminished in size, as is the case with the diseases in most joints*), as to effect the constitution, and also in such parts as have naturally but little powers to heal; we must at the same time include parts that are well disposed to take on such specific diseases as are not readily cured in any situation ; such parts are principally the larger joints, both of the trunk and extremities ; but in the small joints of the toes and fingers, although the same local effects take place as in the larger, yet the constitution is not made sensible of it; we therefore find a scrofulous joint of a toe or finger going on for years without affecting the constitution. The ankle, wrist, elbow, and even the shoulder may be affected much longer than either the knee, hip-joint, or loins, before the constitution sympathizes with their want of powers to heal. Although the hectic commonly arises from some incurable local disease of a vital part, or of a common part when of some magnitude, yet it is possible for it to be an original disease in the constitution: the constitution may fall into the same mode of action, without any local cause whatever, at least that we know of. Hectic may be said to be a slow mode of dissolution ; the general symptoms are those of a low or slow fever, attended with weakness, but more with the action of weakness than real weakness; for upon the removal of the hectic cause, the action of strength is immediately produced, as well as every natural function, however much it was decreased before. The particular symptoms are debility; a

* The cavity of a joint is such as not readily to become smaller under disease, as in the soft parts, which was described in the contraction of sores. 478 HUNTER ON THE BLOOD. small, quick, and sharp pulse; the blood forsaking the skin; loss of appetite; often rejection of all aliment by the stomach; wasting; a great readiness to be thrown into sweats; sweating spontaneously when in bed; frequently a constitutional purging; the water clear. This disease has been and is still in general laid to the charge of the absorption of pus into the constitution from a sore; but I have long imagined that an absorption of pus has been too much blamed as the cause of many of the bad symptoms which frequently attack people who have sores. This symptom almost constantly attends suppuration when in particular parts, such as the vital parts, as well as many inflammations before actual suppuration has taken place, as in many of the larger joints, called white swellings; while the same kind and quantity of inflammation and suppuration in any of the fleshy parts, and especially such of them as are near the source ofthe circulation, have in general no such effect; in those cases, therefore, it is only an effect upon the constitution produced by a local complaint, having a peculiar property, which I shall now consider. I observed, that with all diseases of vital parts, the constitution sympathized more readily than with diseases of any other parts; and also, that all diseases of vital parts are more difficult of cure in general than those which are not vital: I have observed, likewise, that all the diseases of bones, ligaments, and tendons affected the constitution more readily than those of muscles, skin, cellular membrane, etc., and we find that the same general principles are followed in the universal remote sympathy, produced by local diseases of those parts. When the disease is in vital parts, and is such as not to kill by its first constitutional effects, the constitution then becomes teazed with a complaint which is disturbing the necessary actions of health, the parts being vital;, there is, besides, the universal sympathy, with a disease which gives the irritation of being incurable. In the large joints it continues to harass the constitution with a disease where the parts have no power, or what is more probable, have no disposition to produce a salutary inflammation and suppuration; the constitution, therefore, is also irritated with an incurable disease. This is the theory of the cause of the hectic, which will be further illustrated; but now let us consider how far the idea of the absorption of matter may be a cause. If the absorption of matter always produced such symptoms, I do not see how any patient who has a large sore could possibly escape this disease, because we have as yet no reason,to suppose that any one sore has more power of absorption than another. If in those cases where there is a hectic constitution, the absorption is really greater than when the habit is healthy, it will be difficult to determine whether this increase of absorption is a cause or an effect. If it be a cause, it must arise from a particular disposition in the sore to absorb more at one time than common, even while it was in a healthy state; for the sore must be healthy, and then EFFECTS OF INFLAMMATION, ETC. 479 absorb, which hurts the constitution; moreover, as the sore is a part of that constitution, it must of course be affected in turn; and what reason we have to suppose that a healthy sore of a healthy constitution should begin to absorb more at one time than another I must own I cannot discover. If this increase of absorption does not depend upon the nature of the sore, it must then take its rise from the constitution; and if so, there is then a peculiarity in the constitution, so that the whole of the symptoms cannot arise entirely from the absorption of matter as a cause, but must depend on a peculiar constitution and absorption combined. If absorption of matter produced such violent effects as are commonly ascribed to it (which, indeed, are never of the inflammatory kind, but of the hectic), why does not the venereal matter do the same 1 We often know that absorption is going on by the progress of buboes, and I have known a large bubo, which was just ready to break, absorbed, from a few days' sickness at sea, while the person continued at sea for twenty-four days after; yet in such cases no symptoms appear till the matter begins to have its specific effects, and these very symptoms are not similar to those which are called hectic. From reasoning, we ought to expect that the venereal matter would act with greater violence than the common matter from a healthy sore. Although matter, too, is frequently formed on the inside ofthe veins in cases of inflammation of their cavities,* and this matter cannot fail of getting into the circulation, yet in these cases we have not the hectic disposition, but only the inflammatory, and sometimes death. We likewise find very large collections of matter, which have been produced without visible inflammation, such as many of the scrofulous kind, and which are wholly absorbed, even in a very short time, yet no bad symptoms follow.f We may therefore from hence conclude, that the absorption of pus from a sore into the circulation cannot be a cause of so much mischief as is generally supposed; and if it was owing to matter in the constitution, I do not see how these symptoms could ever cease till suppuration ceased, which does not readily happen in such constitutions, their sores being tedious in healing. We find, however, that such patients often get well of the hectic before suppuration ceases, even when no medicine was given ; and in the case of veins there is great reason to believe that after all the bad symptoms are removed, suppuration is still going on, as we find it so in a sore ; pus may therefore still pass into the constitution from the veins, and yet the hectic mav not be produced, which would certainly be the case if those bad symptoms were occasioned by the matter getting into the circulation. But I very much doubt the fact of absorption going on more in one sore than another; and if ever it does 1

* Vide Paper entitled " Observations on the Internal Coats of Veins," at the

^ if mav "hoover, be objected to this, that this is not true matter or pus ; but it may be necessary to show that the one affects the constitution upon absorption more than the other. 480 HUNTER ON THE BLOOD. think it is of no consequence ; I am much more inclined to believe that this hectic disposition arises from the effect which irritation of a vital organ and some other parts, such as joints (being either incurable in themselves, or being so to the constitution for a time) have on the constitution. We may remark, that in large abscesses which have not been preceded by inflammation, the hectic disposition seldom or never comes on till after they are opened (although they may have been forming matter for months); but in such cases the disposition often comes on soon after opening, and in others very late. Till the stimulus for restoring parts is given, no such effect can take place; and if the parts are well disposed to heal, no hectic disposition comes on, neither is the constitution at all affected. In diseased joints also, which are attended with inflammation, if the parts were capable of taking on a salutary inflammation, we should have only the first sympathetic fever ; but as they seldom, are capable of doing this, the constitution becomes teased with a complaint, not taking on the immediate and salutary steps towards a cure. In the venereal disease, too, where we know that the venereal matter has got into the constitution, and that the matter is producing its specific effects, no hectic comes on, till the constitution is harassed with an incurable disease, and this not till long after all the parts are healed with regard to recent disease, and no matter is formed for further absorption. That absorption does take place in sores we have reason to believe, and upon this fact a mode of dressing sores has been advised. The following is a remarkable instance of it in a bubo. A young man had a chancre and three buboes, one of which appeared when the other two were almost cured. This was very large, and at the bottom of the belly. When it had suppurated, and was pretty near breaking, it diminished very quickly, and in two or three days was entirely gone. While this was going on he observed that his urine was wheyish and thick while making it, which went entirely off when the bubo had subsided. Before the bubo began to subside he was rather mending in his health, which continued to mend ; nor did the diminution ofthe bubo alter the state of his health. The hectic, from what has been said, appears in some measure to depend on the parts being stimulated to produce an effect which is beyond their powers; that this stimulus is sooner or later in taking place in different cases, and that the constitution becomes affected by it. The hectic disposition arises from diseased lungs, lumbar abscesses, white swellings, scrofulous joints, etc.

§ 2. The Treatment ofthe Hectic.

We have as yet, I am afraid, no cure for any of the consequences above related; I believe that depends on the cure of the cause, viz., the local complaint, or on its removal; the effects, I EFFECTS OF INFLAMMATION, ETC. 481 fear, are not to be cured. Strengtheners, and what are called antiseptics, are recommended. Strengtheners are proposed on account of the debility which has taken place. Antiseptics have been employed from an idea that pus, when absorbed, gives the blood a tendency to putrefaction. To prevent both of these effects from taking place the same medicines are however recommended. These are bark and wine. Bark will, in most cases, only assist in supporting a constitution. I should suppose it impossible to cure a disease of the constitution till the cause be removed; however, it may be supposed that these medicines may make the constitution less susceptible of the disease, and may also contribute to lessen the cause, by disposing the local complaints to heal; but where the hectic arises from specific disease, as, for instance, if a hectic disposition comes on from a venereal disposition, bark will enable the constitution to support it better than it otherwise could have done, but can never remove it. Wine, I am fearful, rather does harm if it increases the actions of the machine without giving strength, a thing carefully to be avoided: however, I have not yet made up my mind about wine. When the hectic arises from local disease in such parts as the constitution can bear the removal of, then the diseased part should be removed, viz., when it arises from some incurable disease in an extremity; and although all the symptoms above described should have already taken place, we shall find that upon a removal of the limb the symptoms will abate almost immediately. I have known a hectic pulse at one hundred and twenty sink to ninety in a few hours upon the removal ofthe hectic cause. I have known persons sleep sound the first night without an opiate, who had not slept tolerably for weeks before. I have known cold sweats stop immediately, as well as those called colliquative. I have known a purging immediately stop upon the removal of the hectic cause, and the urine drop its sediment. It is possible, too, that the pain in the operation, and the sympathetic affection of the constitution may assist in these salutary effects. It is an action diametrically opposite to the hectic, and may be said to bring back the constitution to a natural state.

Dissolution is the last stage of all, and is common to, or an immediate consequence of, all diseases, whether local or constitutional. A man shall not recover of a fever, whether original or sympathetic, but shall move into the last stage, or dissolution. It shall take place in the second stage of a disease, where the state of constitution and parts appears to be formed out of the first; as, for instance, a man shall lose his leg, especially if above the knee, or have a very bad compound fracture in the leg; the first constitutional symptoms shall have been violent but all shall appear to have been got the better of, and .there shall be hopes of recovery, 482 HUNTER ON THE BLOOD. when suddenly he shall be attacked with a shivering fit, which shall not perform all its actions, viz., shall not produce the hot fit and sweat, but shall continue a kind of irregular hot fit, attended with loss of appetite, quick low pulse, and sunken eyes, and the person shall die in a few days. Or he shall go into the common diseased symptoms of the second stage, viz., the nervous, with many of its effects, as the tetanus, and dissolution shall also be a consequence. Or if the local disease does not or cannot heal, and is such as to affect the constitution, it then brings on the hectic, and sooner or later dissolution takes place : for the hectic is an action of disease, and of a particular kind; but dissolution is a giving way to disease of every kind, and therefore has no determined form arising from the nature of the preceding disease. It has been supposed that this disease arises also from the absorption of matter. It appears to be in many cases an effect arising from violent and long-continued inflammations and suppurations, although not incurable in themselves, (therefore in those respects not similar to the hectic,) and which in many instances are known to produce the greatest changes in the constitution. Such often arise from very bad compound fractures, from amputations of the extremities, especially the lower, and more particularly the thigh, in which cases the sympathetic fever has run high, which would appear to be necessary or preparatory; but in the hectic it is not necessary that the constitution should have suffered at all in the first stages ofthe disease: dissolution seems to be more connected with what is past than with the present alone, which is the reverse of the hectic. We never find this disease take place in consequence of small wounds, or such wounds as have affected the constitution but little in its first stages, but which may affect the constitution much in its second, such as small wounds producing the lock-jaw. It would appear to take place in our hospitals more generally than in private houses, and more readily in large cities than in the country. We shall find that the hectic and dissolution are by no means the same disease, but differ exceedingly in their causes and in many of their effects; for in the case of compound fractures and amputations, we find the constitution often capable of going through the inflammatory and sympathetic fever, producing suppuration and granulation, as well as continuing the production of these for some time, and yet sinking under them at last, and often immediately, without a seeming cause. This effect will more readily take place if the person was in full health before the accident or operation than if he had been somewhat accustomed to the other, or true hectic; for the symptoms of dissolution seldom or never take place, if the violence committed has been to get rid of a hectic cause. It sometimes takes place early, in consequence of local injury, and would seem to be a continuation of the sympathetic fever; as if the constitution was not able to relieve itself of the general affection, or that the parts could not go into the true suppurative disposition. We see this frequently after removing a limb, EFFECTS OF INFLAMMATION, ETC. 483 especially the lower extremity, and after cutting for the stone in very fat men, above the middle age, and who have lived well. The first symptoms are generally those ofthe stomach, which produce shivering; vomiting immediately follows, if not an immediate attendant; there is great oppression and anxiety, the persons conceiving they must die; there is a small quick pulse; perhaps bleeding from the whole surface of the sore; often mortification, with every sign of dissolution in the countenance; and, as it arises with the symptoms of death, its termination is pretty quick. Here is a very fatal disease taking place, in some almost immediately, when all appeared to be within the power of the machine, and therefore cannot immediately arise from the sore itself, for it is very common after such operations as usually do well; but the hectic always takes place in consequence of those sores which seldom or never get well in any case; yet the sore certainly assists in bringing on dissolution, because we never see the disease take place when the sore is healed, nor in those where the constitution seems not to be equal to the task, as is the cause of the hectic. The hectic is much slower in its progress, and seems to be a simple and an immediate effect, arising from a continued cause which is local; by removing the cause, therefore, the effect ceases, and the havoc made upon the constitution is soon restored: persons therefore do much better in consequence of the hectic having in some degree taken place prior to the removal of the cause. But dissolution is a change of the constitution in consequence of causes which now do not wholly exist, and in many cases it does not take place till the constitution appears to be capable easily of performing all its functions, and a removal of the parts does not relieve, as in the hectic ; for dissolution does not depend for its continuance upon the presence of the disease. Death or dissolution appears not to be going on equally fast in every vital part; for we shall have many people very near their termination, yet some vital actions shall be good and tolerably strong; and if it is a visible action, and life depends much upon this action, the patients shall not appear to be so near their end as they really are. Thus I have seen dying people whose pulse was full and strong as usual on the day previous to their death, but it has sunk almost at once, and then become extremely quick, with a thrill. On such occasions it shall rise again, making a strong effort, and after a short time a moisture shall probably come on the skin, which shall in this state of pulse be warm, but upon the sinking of the pulse shall become cold and clammy; breathing shall become very imperfect, almost like short catchings, and the person shall soon die. It would appear in many cases that disease has produced such weakness at last as to destroy itself: we shall even see the symptoms or consequences of disease get well before death. A gentlewoman, who was above seventy-five, was anasarcous all over; the abdomen was very full and large; she made but very little'water; her breathing was so difficult as to make her purple in the face, so that most probably there was water in the chest; 484 HUNTER ON THE BLOOD. her pulse was extremely irregular, fluttering, trembling, intermitting, and small. Her legs were punctured with a lancet, and discharged very freely for more than three weeks, which emptied the cellular membrane of the body, as well as in some degree the abdomen; the breathing became free and easy, so that we supposed the water in the chest was absorbed; the pulse became regular, soft, and fuller, and the appetite in some degree mended; in which state she seemed free from disease, having only some of the consequences still remaining: the quantity of urine increased to the natural quantity; but, notwithstanding actual disease seemed to be gone, yet she became weaker and weaker, in which state she existed for near a month, and died. Some days prior to death a purple and then a livid appearance came upon the legs, with some spots of extravasated blood above where the punctures had been made, on which blisters arose, at first filled with serum, then with bloody serum, all of them threatening mortification. Even when in the state of approaching death we often find a soft, quiet, and regular pulse, having not the least degree of irritability in it, and this when there is every other sign of approaching death, such as entire loss of appetite, no rest, hiccup, the feet cold, and partial cold, clammy sweats, &c. A lady appeared to have lost all diseased action, only the consequences of disease remaining, viz., weakness, with swelled legs: she made little or no water; at length she became so weak as hardly to articulate; she lay in a kind of doze, was only roused to impression, and only took food by spoonfuls when desired; the pulse so small as hardly to be felt. Her extremities were cold, and she had all the signs of approaching dissolution, which took place; yet within thirty-six hours before she died, the whole water in her legs and thighs was taken up, her urine increased, and about ten hours previous to her death, the legs, &c, were as small as ever. As I consider the dropsy to be a disease, and not simply weakness, which this case would in some measure show from the result, I should wish to ask whether the absorption of water was not owing to the disease being gone ? and whether the disease being gone, the absorbents did not set to work 1 If so, then dissolution may be a cessation of disease, and persons die of weakness simply; or simply either the want of powers to act, or the want of that stimulus of necessity to act, by which means a cessation of action takes place. Since bodies of persons who die suddenly, and even by violent death, as well as those who die soon after a considerable operation, are not capable of being preserved so long as those who have been ill for some time ; and as those who have a considerable operation performed upon them, as the amputation of a leg, do not so readily recover as those who have been long ill, may not the more ready production of death and the more ready production of putrefaction be owing to the same principle, one more readily running into the action of death as also more readily into the action of putrefaction? But it is very probable that the action producing quick putrefaction is an action prior to absolute death. THE TREATMENT OF ABSCESSES. 485 PART III. CHAPTER I.

THE TREATMENT OF ABSCESSES.

I have endeavoured to lay down the general principles of suppuration, which principles of themselves lead to a general method of cure; but as it is only the proper application of art to those principles which completes the surgeon, and since it is the most difficult part to apply our knowledge of first principles to practice with readiness, especially when there appear some peculiarities, it' will be necessary to bring the beginner from first principles to the practical part. Abscesses are in general consequences of spontaneous inflammation, but not always so ; for they may be consequences of some violence, as strains or bruises from some external violence, which has hurt deeper-seated parts than the skin over them, which inflame and form an abscess, as was described in treating of accidents; as also from the introduction of extraneous bodies, over which the parts have healed. Even when they appear to be spontaneous, they arise from so many causes, and from thence have so many dispositions, or are of so many kinds, that in general they become one of the greatest objects in surgery; because, from these circumstances, they require a vast variety in the manner of treatment. I do not mean at present to enter into a full discussion of the cause, effect, and cure of every abscess, because that would be treating of every disease which is capable of producing such complaints, many of which would come under the article of specific diseases, which must be treated of separately; yet I mean here to lay down such general surgical rules for their treatment and many of their consequences, as will include almost every kind of disease of this kind, considered as an abscess simply. So that the specific treatment of any specific abscess will be principally confined to the medicinal treatment of the part and the constitution ; thereby the treatment of the local complaint so produced, abstracted from the specific disposition, will for the most part come under our general rules. As most spontaneous suppurations, from whatever cause, are deeper-seated than the surface of the body, such of course must form what are called abscesses, or collections of pus; therefore 486 HUNTER ON THE BLOOD. we have abscesses of all depths, from the pimple in the skin to the boil, and from the boil to deep-seated abscesses among the muscles, or in any other deep-seated part. Abscesses are commonly formed where matter is found, especially the more superficial ones, and such may be justly called abscesses of this part; but collections of matter are often found in parts where not formed, more especially in the deeper-seated ones ; the matter moving from the seat where it was formed to some more depending part, or having met with some obstruction in its course, it takes another direction, and therefore may be called an abscess in this part; and I shall call them so in my descriptions of them. I believe such abscesses do not arise from inflammation, but are of the scrofulous kind, and therefore not so much to our present purpose. It will be difficult to divide abscesses into absolutely distinct classes; but, similarly to inflammation, they may be divided into two kinds, the sound and the unsound; for I imagine these two first principles might lead to the method of cure; but at present I only mean to lay down the principles of an abscess. The appearances which distinguish the sound from the unsound abscess are several; although there are many abscesses of particular kinds that give little or no information. They often differ from one another in their first appearance from the kind of inflammation, as also in their course, but more particularly in their efforts toward a cure. Thus we judge of the consequences of the small-pox from the first appearance of the arm after inoculation; for if the beginning inflammation is small, pretty much circumscribed, and of the florid red with some rising, then we may in our own minds expect a good kind; the same upon the first appearance ofthe small-pox themselves ; as also the first appearance of chancre, etc., or almost of any other disease, either beginning with or attended by inflammation ; for it is by the kind of inflammation we are to judge of the future event. It might be thought almost unnecessary here to treat of sound abscesses, because in such our first principles will readily take place, and often little or no assistance is required ; but abscesses may be attended with circumstances which may retard the cure, and which have nothing to do with unsoundness, such as extraneous bodies in sound parts; and these will most probably come under our general principles of cure, that is, require something to be done, because they will in many cases relieve themselves of the extraneous matter, and then they require but little assistance.

§ 1. The Progress of Abscesses to the Skin.

What I mean by a sound abscess, is where there is a sound constitution, the parts affected having all the disposition and powers to heal, and those dispositions and powers allowed to take place, which will happen more readily if in structures of the body which have THE TREATMENT OF ABSCESSES. 487 naturally a ready disposition to heal; so situated in the body as to be able to support its actions, and not of a specific kind, for which we have no cure; for any specific disease, for which we have a cure, will come within our first division.* The inflammation in a sound and active part, and of a sound constitution, in general is pretty violent, attended from the very beginning with a considerable deal of pain;f suppuration takes place quickly; the parts between the abscess and the skin are readily affected, and ulceration goes on fast; the skin becomes of the florid red; the matter comes soon to it, especially at a point,J and it bursts; all this is done with great rapidity. The symptoms show such a degree of health in the constitution and the parts, that little is necessary for the surgeon to do in the first stages of the disease. Poultices are recommended in such cases to assist that disposition which the parts have to give way between the skin and the abscess; but I have already observed, that they certainly can have no effect of this kind ; however, they have their uses when the inflammation has reached the skin, for they keep it soft, allow the cuticle to distend, and give way to the swelling underneath, which eases the patient. Warmth and moisture act in many cases as sedatives to our sensations, although not always; and the distinction between those where they give ease, and where they rather give pain, I have not been able to make out. As an abscess of the healthy kind requires but little surgical treatment, between its commencement and opening, it also requires but very little attention afterwards for the cure or the restoring the parts. This depends more on the operation of the powers or abilities the machine is in possession of, than on any assistance the surgeon can give; however, abscesses may have other circumstances attending them, besides soundness and unsoundness, which will require surgical treatment; such as the extraction of exfoliated bones, which by their stay retard the cure. Further, as few inflammations arise in perfectly sound parts and constitutions, it will generally be necessary to treat them in some degree as if they had an unsound tendency, and also according to other circumstances.

* Viz., if a venereal abscess has its specific quality destroyed, it admits of cure as readily as any other, and the same treatment becomes necessary. f Vide Symptoms of Suppurative Inflammation. \ This very appearance makes a material difference between an abscess arising from brisk inflammation, and one that is slow in its progress ; it is so remarkable, that I have seen this effect where the matter was at such distance as not to be felt in the least, and where I have doubted whether there was matter or not, almost conceiving that it preceded suppuration. It certainly has this effect long before there is any distension: besides this, of a pointing taking place, there is another effect of deep suppurations in consequence of inflammation, which is an oedematous appearance, or thickening ofthe superficial parts. This was taken notice of by Le Dran in internal abscess of the abdomen, where adhesions had taken place between tbe suppurating part and the parietes of the abdomen, and by Mr. Pott in suppuration of the brain; whether in such there is a pointing or not I do not know. 488 HUNTER ON THE BLOOD. As no abscess can set about a cure till the matter is discharged, the first process, therefore, is the discharge of the matter; but simply discharge is not always sufficient; therefore it becomes necessary to consider whether or not, almost in every case it would not be proper to do more ; and I am inclined to believe that whatever would in general assist an unsound abscess, would also do the same to a sound one; but this practice should be followed with great caution, and not carried too far, for in many it will be perfectly unnecessary, therefore it should not be practised ; in others it will only be necessary in part; besides, in many cases it may do harm, for many abscesses may have tolerable dispositions under the present treatment, yet may be in such a state as very readily to fall into an unsound one, of some kind or other, when too much violence is committed; some having a tendency to irritability: on the other hand, our.practice may fall short of the intention, as "many parts have a strong tendency to indolence; and if the stimulating method is applied to the first it would be unlucky, and vice versd. It will be generally more in the power of the parts to perform a cure if certain operations are done, which even dispose the most active and healthy disposition, both of constitution and of parts to heal sooner; but this does not hold of the irritable. The first of these operations will be the mode of exposing abscesses, by opening them sufficiently, which will make any particular treatment afterwards, either less necessary, or more easy of application, if necessary ; so that the first principle of the cure, even of sound abscesses, may be the freedom of opening them in the beginning; however, the more sound they are, there is the less necessity for such treatment; for if it does not give new' powers to the parts, it keeps up those of which they are already in possession, and obliges them to go on towards a cure; for the living principle in parts, more especially sound parts, seems uneasy under the circumstance of exposure, and of having no skin, and therefore is roused to action, acting with a view to cover the part. It has no alternative; and, as I have just now observed that few spontaneous abscesses take place from so slight a cause as simple violence produces, there must be a something to be got the better of. This is, perhaps, as well illustrated in the fistula in ano, as in any other; for without dividing along the gut to the bottom, which is where, the disease is, and where the abscess has formed, it seldom or never heals; however, all this will be according to circumstances, for if the suppuration is quick and comes fast to the skin, the parts will heal in the same proportion more readily, either with or without opening; therefore, in such instances, it is not so necessary to open freely, though as it is not the method nature commonly takes, it has by many been • objected to; but let us observe, that where an abscess opens of itself by a small orifice, the parts are commonly very sound where the opening is, although the bottom may be diseased; but if it be diseased where it opens, then ulceration commonly takes place at this orifice, which effects what should be done by art. THE TREATMENT OF ABSCESSES. 489 To illustrate that a large opening is not detrimental to the healing of a sore, let us observe that there is no difference between an abscess opened largely, and a wound in consequence of an operation which is not healed by the first intention, such as an amputation, etc.; for in such cases there is a breach in the continuity of the parts communicating with the skin, as large, if not larger than at the bottom, and it heals readily. We endeavour, however, to remedy this as much as possible by saving skin, which, in some degree answers to a small opening; and we may also observe that where there is only a small opening leading to a large cavity, which is to suppurate, as in the case of a hydrocele treated by a caustic or seton, (which when come to suppuration is in all respects similar to an abscess,) the whole so far as suppuration extends, heals equally well with those that are wholly exposed ; but I do not know that they do better: and where the sac is not very sound I do believe they do not so well as when more fully enlarged: and we may also observe, that opening largely into the scrotum is not subject to the same inconvenience as in many other parts, for here there is so much loose skin as to remove any retardment to the healing that might arise in other parts from opening largely: however, after viewing this in every light, there seems but little advantage gained in the one way or the other. The opening more or less freely must be directed "by some other circumstance, by which the surgeon must be guided. But as most abscesses owe some of their size to distension, and as this will be more or less according to circumstances, it becomes necessary to distinguish the one kind from the other, for the one will require a freer opening than the other. Abscesses in soft parts will owe more of their size to distension than those in hard parts, such as bones, joints, etc. Abscesses in soft parts, not connected with the hard, will owe more of their size to distension than those in soft parts connected with the hard; for instance, an abscess in the calf of the leg, thick of the thigh, buttock, etc., will owe more of its size to distension than an abscess on the shin-bone, on the head, etc. Therefore an abscess, whose size is in some degree owing to distension, need not be so freely opened as one that is not; because when the distension is taken off by the discharge of the pus, the parts will contract, or fall into their natural position, which cannot so easily happen in the other case. Besides, the granulations will also be allowed to contract in the one case, much more than in the other. Hdwever, we find many abscesses healing very readily without any other opening than what was at first made by ulceration, and this will be more readily effected if the abscess has been allowed to break of itself, which I shall now more fully explain. § 2. Of the Time when Abscesses should be opened. The natural process that abscesses are obliged to go through for the discharge of their contents is in general the most proper, and 490 HUNTER ON THE BLOOD. it is so much so as to be in most cases allowed to go on; and this process becomes more necessary in unsound abscesses than in sound ones, as it exposes them more fully, from ulceration having destroyed more ofthe parts between the seat ofthe abscess and the external parts. As abscesses, wherever formed, must increase as they approach the skin, and therefore increase that part of their cavity next to the skin faster than at the bottom, so that they become in some degree tapering towards the bottom, with a wide part immediately under the skin; and this will be more or less so, according to their depth, their meeting with different substances which give a resistance to the pus, or their coming fast or slowly to the skin. This shape of the abscess, when allowed to take place, is well adapted for healing; for it puts the bottom, which is the seat ofthe disease, more upon a footing with the mouth of the abscess than it otherwise could be. When these two are not well proportioned there is a retardment in the cure; for as the bottom, or part where the abscess begun, is more or less in a diseased state, and as the parts between the seat of the abscess and the external surface are sound parts, having only allowed a passage for the pus, they of course have a stronger disposition to heal than the bottom has; and we commonly find this to be the case. If there could be made at any time a difference in the powers of healing between the mouth of the abscess and its bottom, it ought to be made the most defective at the mouth of the abscess, as that part is the easiest of management. To have this effect produced as much as possible, abscesses should be allowed to go on till they break or open of themselves; for although abscesses in general only open by a small orifice, more especially when sound, yet it is to be remarked that the skin over the general cavity of the abscess is in such cases so much thinned as to have but very little disposition'to heal, and is often so much so as to ulcerate and make a free opening : and if it does not, an opening is more easily procured by art. It is a curious circumstance in the ceconomy of abscesses that those that have the best dispositions to heal come fastest to the skin ; the lead takes place almost at a point, it does not swell so much into that conical form above described, not being under the same necessity in point of healing, and it opens by a small orifice ; while, on the other hand, if there is an indolence in the progress of the abscess it will spread more, or distend the surrounding parts, from their not being so firmly united by inflammation in the one as they were in the other; nor will ulceration so readily take the lead, and it will come to the skin by a broad surface, so as to thin a large portion of the skin. But abscesses should only be allowed to open of themselves where the confinement ofthe matter can do no mischief, which will generally be in such as ought to heal up from the bottom ; but in the reduction of circumscribed cavities to the state of an abscess it will be in most cases proper to open early, as THE TREATMENT OF ABSCESSES. 491 in abscesses of the abdomen or thorax, those within the cranium, those of the eye, and those in joints. In the abscess of the tunica vaginalis testis it would be better to let it open of itself, as it should be allowed to heal up from the bottom, similar to an abscess in the cellular membrane. If it should be unnecessary to open freely, or if from circumstances this should be impossible, it will in either case be very proper to make the opening which is necessary or practicable at the most depending part, with a view to remove the pressure arising from the matter collected, which is commonly called confinement or lodgement of matter, which will otherwise happen; for I shall observe that a very small pressure on that side of the abscess next to the skin may produce ulceration there; and although this pressure in many cases might not be so great as to produce ulceration at the bottom of the abscess, yet it may be so great as to prevent granulations from forming on that side,"and thereby retard the cure, as no union can take place but by means of granulations ; or if it should not prevent granulations from forming, yet it might retard their growth, so that the cure would be more tedious than if the pressure did not exist; and this retardation will be greatest where the pressure is the greatest, which will be at the most depending part of the abscess; so that its upper part will readily heal to a small point, and be reduced to the state of a fistula. But it is not always possible to open at the most depending part of an abscess, and when possible often very improper. When impossible, perhaps nothing more can be done than to evacuate the matter as often as necessary, and by gentle pressure keep the sides of the sinus together, to allow their growing into one another; but the situation will not in all cases allow this. The inexpediency of opening at the most depending part of an abscess will in general arise from the distance between the matter and the skin at this part; for if the abscess is pretty deeply seated, and points at a part superior to that of its seat, which it sometimes does from the parts above, being such as more easily give way, in such a case it will be proper to open it where it points. For instance, if an abscess is formed in the centre of the breast, and opens at the upper part, (which is often the case,) it would be improper to cut through the lower half to allow the matter to pass that way • although it may make its way there afterwards, from the pressure of the matter, as was just now observed; which I have seen happen more than once. „ , . . . . If an abscess forms on the upper part of the foot, it is improper to open through the sole of the foot to get at the most depending part of the abscess, for besides cutting such a depth of sound parts, which is an objection, it would be destroying a great many useful parts. It would also be impossible to keep it open, the sound parts having such a disposition to heal; and it would be contradictory to my first position, which was to have parts as thin as possible 492 HUNTER ON THE BLOOD. before they are opened, in order to destroy the healing disposition there.* As in such cases the place where the matter threatens to open a passage for itself is where the future opening is most likely to be, and as the situation is disadvantageous to the healing ofthe seat of the abscess, it will be more necessary to let it first open of itself (because the abscess just under the skin will be increased in width, as was observed), and then to dilate it as freely as may be thought necessary; for by allowing abscesses to open of themselves the opening has a less disposition to heal than if it had been opened early by art; therefore [the former method] is more desirable in such situations.

§3. Ofthe Methods of opening Abscesses, and treating them afterwards.

All abscesses I have already observed will open of themselves, excepting where the matter is reabsorbed; and I have also observed, that in general they ought to be allowed to open of themselves, excepting some particular circumstance calls for an early opening; but when the skin over the abscess is very thin, it is not of so much consequence whether it is allowed to open of itself, or is opened at first by art. In large abscesses it will generally be necessary to open them by art, whether they have opened of themselves or not, for the natural opening will seldom be sufficient for the complete cure; and although it may be sufficient for the free discharge of the matter, yet they will heal much more readily if sufficiently opened, for the thin skin over the cavity granulates but indifferently, and therefore unites but slowly with the parts underneath. Where the skin is very thin, loose, and much of it, it may be necessary to remove an oval piece from the centre, where it is generally thinnest. A question naturally occurs, in what way should these be opened? The methods recommended and used are by incision and caustic. Incision nay or may not remove a piece of the skin, but the caustic always will. I believe, as a general practice, there is no preference to be given to either, but under circumstances the incision is best; for instance, where there is but little skin to spare, as on the shin, scalp, etc., but where there is skin to spare, either arising from situation, as in the scrotum, or where a great deal of skin was thinned, as in a great extent of inflammation and suppuration under the skin, a caustic will answer equally well; therefore I should be very apt to be directed by my patients if they had any fears or opinions about the matter, for some have a terror at the idea of a cutting instrument, while others hate the idea of a continued pain.

* One would imagine that this last caution was hardly necessary, but I once saw a case where it was advised, upon the general principles of opening in the most depending part. THE TREATMENT OF ABSCESSES. 493 If a caustic is approved of, then I should prefer the lapis infernalis vel septicus to the common caustic; the method of application I described when speaking of the methods of producing death by art; but if left entirely to myself, I should prefer the incision to the caustic, because it is immediately done. If an abscess is allowed to open of itself, and this opening is not enlarged, no dressing is necessary, nor anything but to keep the surrounding parts clean; the continuation of the poultice, which was before applied (if convenient), is perhaps as good an application as any, and when the tenderness arising from inflammation is over, then lint and a pledget; but an abscess opened by a cutting instrument may be called a mixed case, being both a wound and a sore, and is more of the nature of a fresh wound in proportion to the thickness of the parts cut, and therefore the dressing should be somewhat similar to that of a fresh wound. It is necessary that something should be put into the opening, to keep it from healing by the first intention; if it is lint it should be dipt in some salve, which will answer better than lint alone, as it will allow of more early extraction; for such sores should be dressed the second time the next day, or the second day at latest, because there is a suppurating sore at the bottom, and the pus requires being discharged much sooner than if wholly either a fresh wound or a circumscribed cavity, which is to suppurate, as the tunica vaginalis in the case of the radical cure of the hydrocele. This pus keeps the lint (if dressed with lint) moist, so that it does not dry, as in fresh wounds in common. When the cut edges have come to suppuration, which will be in a few days, then the dressing afterwards may be as simple as possible, for Nature will in general perform the cure. If the abscess has been opened by caustic, and the slough is either cut out or allowed to slough it,then it is to be considered as an entire suppurating sore, and maybe dressed accordingly; perhaps dry lint is as good as anything, till the nature of the sore is known; if of a good kind, the same dressing may be continued, but if not, then it must be dressed accordingly; for Nature cannot always perform a cure; for parts which were at first sound, or appeared so, from their readiness to go through the first stages, will subsequently take on every species of disease, whether from indolence, from irritability, from scrofulous or other dispositions, which in some cases ^produced from the nature of the parts diseased, such as bone, ligament, etc.

CTh. reciproca! effects of -«^ » ^S^^'iiSSS^

ttSi^sffi »-%«-1°Hunter -must accord ,he 494 HUNTER ON THE BLOOD. merit of applying this mode of inquiry to pathological investigations, conceiving that as each texture was endowed with peculiar properties in a state of health, it would likewise in the same manner be affected in a special manner by the causes of disease, and consequently, that the same modes of lesion would always produce similar effects on all the analogous structures of the body. Bichat still further extended this system in his Anatomie Generate, which appeared in 1801, but without acknowledgments to Hunter ; and it is undoubtedly to this source that we must ascribe the great and rapid advances which have been made in pathological knowledge during the present century. To suppose, however, as some have done, and as was first ably suggested by Dr. Carmichael Smyth in 1790, that the differences of inflammation essentially and almost exclusively depend on differences of structure, is pushing the principle too far ; for, as Mr Hunter has justly observed, in the division of the leg in amputation a great many different structures are divided, and yet they all become affected by the same inflammation, and show no difference, except under peculiar circumstances, in this respect. In fact the same inflammation may affect different structures, or the same structure be affected by different inflammations, or inflammation may be transferred from one structure to another. Structure, therefore, is merely a modificatory cause, and often of the least consequence in giving a peculiar character to the inflammatory action. Cellular Membrane.—This structure forms the basis of all the organs of the body, and therefore may not improbably constitute the proper seat of inflammation, as well as the proper generative tissue, in all cases; for we may observe that the lymph effused in inflammation is always the same, from whatever structure it proceeds; that the process of union is likewise similar for all parts ; and that in the regeneration of tissues the production of cellular membrane is invariably the first effort of the orgaJ nizing principle. It seems not unlikely, therefore, that this uniformity of effect is to be referred to the cellular structure being always affected. The cellular membrane is remarkbly susceptible of inflammation, which is generally characterized by the sthenic type, acute throbbing pain, and the rapid and abundant effusion of coagulable matters. It readily passes into all the terminations of inflammation ; that is, adhesion, suppuration, ulceration, and mortification. Inflammation of this structure in a healthy constitution shows little disposition to spread, in consequence of the cells being speedily united by coagulable lymph ; but under certain states of impaired health, and in particular kinds of inflammation, as, for instance, of the veins, or that arising from the inoculation with morbid poisons, it spreads with great rapidity ; not circumferentially, as in a state of health, but irregularly, attended with comparatively little pain. In consequence of adhesive matter not being poured out, the foul sanies, which is secreted instead of pus, easily pervades the cells of this membrane, and carries devastation before it, producing a quaggy state of the subjacent parts, arising from a mixture of pus with sloughy cellular membrane. The seat of this inflammation is usually the subadipose or subfacial cellular membrane ; and though in its local and constitutional effects it closely resembles the erysipelas phlegmonoides, yet in the former case the skin remains unaffected, so as to conceal in great measure the mischief which has taken place. In these cases simultaneous purulent depositions not uncommonly take place in various situations of the body. (Tr. of Med. and Chir. THE TREATMENT OF ABSCESSES. 495 Soc. of Edin., vol. i.; Edin. Med. and Surg. Journ., xxiv. 225; Travers on Constitutional Irritation; and Med. and Chir. Tr. of London, vol. xvi.) Dermoidal Tissue.—Inflammation of the skin affords the best type of inflammatory affections, for here it is that the external marks of inflammation are most conspicuously developed; the phenomena, however, are much diversified, according to the part of the skin which happens to be affected. If the external layer of the corion is affected, as in erythema and erysipelas, the inflammation is apt to spread ; if the papillae or muciparous follicles, or the bulbous roots of the hair, then the character of the inflammation is that of the circumscribed eruptive disorders; and if the internal and attached surface, then that of the boil, carbuncle, and phlegmon. The skin is easily inflamed by direct mechanical and chemical injuries, but in a state of health this inflammation is not apt to extend itself. It is also peculiarly accessible to inflammation from morbid poisons or vitiated states of the system, and hence the pathological conditions of this system have always afforded the chief arguments to the humoral pathologists. The dermoidal and mucous tissues offer many points of affinity, both in a physiological and pathological view. In both inflammation is apt to migrate from one part to another, overleaping the intermediate portion ; in both pustular and follicular inflammations occur; ulceration and mortification take place in both with great facility, and in both it is observable that their morbid states reciprocally influence one anodier. It may also be noted, that neither of these tissues is subject to the ossific transformation. The regenerative powers of skin are only inferior to those of the cellular membrane, but the new cutis is different from the old, in being devoid of hairs, muciparous follicles, fat, papillae, and epidermis, and sometimes of the rete mucosum, although the three latter are certainly reproduced in many cases after a certain lapse of time. The fibrinous contractile cicatrix, which is generated in burns, is not peculiar to this tissue, but occurs occasionally in mucous and serous membranes, producing in the one set of cases the worst forms of stricture, and in the other a more or less complete atrophy of the organs which it envelopes. Mucous Membranes. This structure, like the skin, is exposed to a variety of external influences and therefore is very subject to attacks of inflammation, which generally commence by separate ramiform patches, which extend with some degree of capriciousness; the urethra, for example, becomes first inflamed towards the orifice, then the membranous portion or bladder, and lastly, the kidneys or testicles ; the intermediate continuous portions of the sound membrane not suffering. The same thing is observed of the air-passages and alimentary canal, the different portions of which become successively, but not continuously affected. The mucous membrane is at first dry, then swells becomes intensely vascular, and often in a high degree villous, the follicles usually enlarge, and the secretion is gradually changed from a highly limpid mucus into genuine pus. There is a great difference, however in this respect; for while some, as the urethra, secrete pus very readily and in great abundance without being prone to ulceration, others, as the intestines are seldom found to produce this fluid without previous ulceration ; while others again as the fauces and tonsils, not unfrequently secrete a peculiar modificalion'of albumen, which, although not organizable, adheres for a •V ., ion(Tfh 0f time to the free surface, and assumes the appear- Zl'^ashtoloured or grayish slough. The bladder and colon 496 HUNTER ON THE BLOOD. secrete a ropy, tenacious mucus, especially in chronic inflammation, while the internal membrane of the stomach and small intestines is reduced, under the same circumstances, to a soft, pulpy condition, so as easily to admit of being scraped off, or even to be removed by the natural actions of the part. Specific disease and poisons are peculiarly apt to attack parts of this system, and at the same time to produce specific eflects, as is seen in croup, dysentery, and scurvy; but in general the prevailing tendency of this system may be stated to be, suppuration, ulceration, and mortification. Occasionally, however, there is considerable submucous infiltration either of serum or lymph, producing in the former case oedema, and sometimes death, when it happens to occur in the larynx, and in the latter permanent cartilaginous strictures. The regenerative powers of this tissue differ in different parts; for in th© bucco-pharyngeal portions they are very considerable, while in the enteric, laryngeal, and urinary portions they are very limited. In extensive regenerations, as at the back of the pharynx, the new membrane is of a different colour from the old, and unprovided either with follicles or villi, in consequence of which it is no longer a secreting surface; but in other cases, especially where a considerable time has elapsed, it is perfectly restored. The lining membranes of certain forms of gelatiniform encysted tumours and sinuses are the natural transition between the mucous and serous classes. Serous membranes. Inflammations of this class are characterized by their tendency to spread and to exude a great abundance of the coagulable parts of the blood ; they are also generally characterized by their acuteness, by the severe and rousing pain which they occasion, and by the great capability which the system evinces under their influence of enduring great losses of blood ; in which Vespect, as well as by their indisposition to take on the suppurative form, they are remarkably contradistinguished from those ofthe former class. Primary ulceration and mortification of this tissue are extremely uncommon; but in certain forms of secondary inflammations, which have been before adverted to, it gives rise to an abundant purulent secretion. Next to the fibrous class, the serous tissue is most subject to metastatic inflammations, as gout, rheumatism, syphilis, etc., and in such cases many parts are often simultaneously attacked. Pathologists are divided in opinion as to the proper seat of this inflammation, some considering it to be the serous membrane itself, and others the subserous cellular tissue, the proper serous membrane being regarded, like the epidermis, as extra-vascular. There is, however, no doubt of the former becoming visibly vascular in some stages of its progress, of the vessels thus formed being in communication with those which are generated in the effused lymph, and of all the other changes of inflammation being produced without visible vascularity, as in the arachnoid membrane ; so that upon the whole there seems no reason to doubt that the serous membranes are themselves inflamed, especially as subserous infiltrations, whether of serum, lymph, or pus, are to be regarded as unfrequent occurrences. After removing a portion of the pleura pulmonalis, Dr. Thomson could not discover any visible cicatrix; from which, as well as from the frequent generation of this tissue in new situations, there is no reason to doubt that this membrane is readily reproduced. The synovial and bursal structures resemble the serous in most leading respects; but the change of structure into a pulpy grayish substance, to which the former are subject, and the tendency to fungoid growths, to which the bursae are liable, have not been observed in the serous mem- THE TREATMENT OF ABSCESSES. 497 branes, although both are extremely prone to cartilaginous and ossific transformations, the result of chronic inflammation; neither are they equally liable to the production of loose cartilages and small ovoid bodies in the form of melon-seeds, nor equally exposed to metastatic inflammations. Fibrous Tissue. Like other dense and unvascular parts, the fibrous tissue exhibits a comparative backwardness to inflammation, the processes of reparation are slowly effected, and ulceration, mortification, and even suppuration are seldom primarily induced. The differing degrees of vascularity, however, in different parts of this system occasion a great difference in this respect. In general there is an abundant effusion of coagulable lymph, which often under such circumstances becomes ossified; but, upon the whole, the reproductive powers of this system are not considerable, so that tendons which have sloughed are not renewed, and ruptures of the capsular ligament, in cases of dislocation, have remained unrepaired for several years. This system is peculiarly obnoxious to inflammation from constitutional causes, as gout, rheumatism, and syphilis, in which cases there is often a metastasis of the disease from one part to another in succession, attended with severe nocturnal exacerbations. The confinement of matter in some of these cases is often productive of great constitutional irritation. Cartilaginous System. It has been doubted whether true cartilage is ever subject to inflammation, principally because it has never been observed to become vascular; but as the phenomena of normal ossification leave no doubt as to the vascularity of this substance in a state of health, there seems no just reason for doubting its capability to inflame, especially as in similar unvascular parts, as the cornea, the arachnoid membrane, and even the teeth, there is no question on this subject. Neither is there any question respecting the vascularity of the fibro-cartilages, although these structures are traceable by insensible degrees into true cartilage, from which indeed they are not essentially different. Still, however, there are some peculiarities respecting the pathology of cartilages which are not easily explained; as, for example, the extreme dissimilarity which they exhibit in regard to the two forms of ulcerative and progressive absorption ; the former of which takes place with the greatest readiness, and the latter with the utmost difficulty. Ulceration of the harder cartilages is sometimes unaccompanied with suppuration. It is generally, however, attended with a high degree of irritative fever, as compared with the actual extent of the disease, and often with partial exfoliations. The reproductive powers of cartilage are very limited, and it is observable that this substance invariably unites by osseous union. Osseous System. The peculiarities of ostitis are principally refernble to the peculiar hard texture of bone, which does not admit of that rapid extension of vascularity which the reparative processes of inflammation seem to require; consequently all the processes of bone are extremely tedious, so that in some cases several years are required for the complete disjunc ion of a dead from a living portion. The general principle of parts being less accessible to inflammation in proportion as they are dense in structure and deficient in vascularity, holds good in respect to bones, which are rarely subject to idiopathic inflammation ; the compacter cordons being less subject than those which are more porous although both are much more so than tendons, fasciae, and cartilages. Still, however bones are much exposed to chronic inflammation from mercury, 498 HUNTER ON THE BLOOD. syphilis, gout, rheumatism, scrofula, &c, giving rise to various forms of hyperostosis. Bones become very vascular when inflamed, and the harder parts readily perish. In nearly all cases the texture of the bone is much loosened by inflammation, and a part of the earthy matter is absorbed, so that when macerated and dried it exhibits a light and spongy fabric; in some rare cases it acquires unusual density, approaching to the nature of ivory. The union of bone is precisely similar to that of soft parts, while its reproductive powers are of a high order, leading not only to the complete regeneration of entire shafts of bone, but to the perfect restoration of the organization to the normal state ; in which respect, perhaps, they are not equalled by any other structure of the body. Muscular Tissue. This tissue appears to be the least liable to inflammation and its consequences of any structure of the body. When inflammation attacks this structure from wounds, &c, it becomes soft and lacerable, and of various shades of green, brown and red; but in such cases it is not observed that the inflammation has any disposition to extend along the whole course of the muscle. I have sometimes seen a diffused suppuration in the substance of muscles in secondary inflammations, as well as in inflammations arising from wounds received in dissection, and circumscribed abscesses have occasionally been discovered in the substance of the heart in carditis. Muscle is never reproduced, but the union is invariably effected by a fibro-ligamentous structure. Vascular System. The arteries differ very remarkably in their liability to inflammation as compared with the lymphatics and veins, as well as in their constitutional effects and morbid changes. Inflammation of the internal coats of arteries must be considered as very uncommon, and rarely advances to the suppurative stage, whereas nothing is more common than inflammation and suppuration of the veins and lymphatics, attended with low typhoid symptoms, secondary suppurations in various situations of the body, and very often death. Chronic inflammation also, leading to considerable thickening of the venous tunics, is sufficiently common. In inflammation of the veins and lymphatics the adjacent tissues are always more or less involved, so that their course is indicated by hard and painful lines. Mr. Hunter has remarked that this system resists the effects both of ulceration and mortification beyond all other tissues; and with regard to mortification they are not, I believe, ever primarily affected in this way. The reproductive powers of vessels are certainly of the highest order, although differing in some measure from other parts. In an instance already referred to (see note, p. 235), new vessels were actually produced capable of performing all the functions of the old; but in general when large vessels are obliterated their office is vicariously performed by the enlargement of others which had previously existed. Nervous Tissue. Little is known respecting the nerves. That they become inflamed and thickened in certain cases of local neuralgic disease has been demonstrated by dissection, but in other cases no such appearances have been observed ; neither is it known whether they are ever primarily affected by ulceration, suppuration, or mortification. The question as to the regeneration of the proper nervous tissue is still undecided. The proper medullary matter of the brain and spinal marrow is subject to acute and chronic inflammation, like other parts ; probably the former, however, never takes place idiopathically, but from injuries and poisons only, when it is generally limited in its extent and characterized by a red colour of various degrees of intensity, verging towards brown, green, or THE TREATMENT OF ABSCESSES. 499 yellow, and terminating in a state of diffluence. Chronic inflammation is much more frequent, attended with increased vascularity at first, but as the brain becomes softened, with a red, yellowish, or whitish colour, marking three several kinds of mollescence, depending on the effusion of blood, pus, or serum. There seems reason, however, for believing that this pulpy disorganization of the brain may take place independently of inflammation. The most remarkable circumstance connected with this tissue is the occurrence of large chronic abscesses, generally inclosed in thick cysts, and unattended with any symptoms during life. These I have known to occupy one entire hemisphere of the brain. Ulceration sometimes occurs towards the surface of the convolutions, and by some the diffluent state of the brain before spoken of is thought to resemble mortification. 2. It has been before stated that all the functions of a part are modified by inflammation ; of these, however, two only are susceptible of examination, viz., secretion, including the inflammatory effusions, and nutrition: the former of these has been already considered, and it only remains to make a few observations respecting the latter. The effects of inflammation as regards nutrition may be divided into two primary classes, including, in the first place, those which have respect to the physical properties of parts; and, in the second place, those which have more immediate reference to their organical constitution. These, it must be obvious, often run up into each other, so as to render any satisfactory classification of the phenomena impracticable. The primary effects of inflammation, or those which regard the physical properties of parts, are several. Induration, as regards the soft parts, is one of the most universal effects of inflammation, and may be said to depend on the interstitial deposition of lymph in the interspaces of the natural organization, which in process of time becomes converted into the same nature as the part itself. These effects are more or less permanent in different cases. In general, parts are found to revert to their former state upon the subsidence of the inflammation ; but in other cases this does not happen, in consequence it may be presumed of the normal organization of the part being permanently iniured : as, for instance, in the iris, which is often irretrievably destroyed by acute iritis. Instances of induration remaining, after the augmentation of bulk has subsided, occur in the liver, brain, muscles, spleen, and particularly in the eburnation of the articular extremities of bones from which the cartilages have been denuded. Softening also is a very frequent consequence of inflammation, particularly of the cellular membrane, as is evinced in the diminished cohesion of parenchymatous organs, and the weakened attachment of membranousexpansions to the parts which they cover. The harder textures, as bone, tendon, cartilage, &c, are most frequently softened by inflammation, in thes'ame manner as the softer textures are mos^frequendy hardened ; but these effects are sometimes reversed. Softening has been Sbed to the infiltration of serum and pus d-ntegrating^, healthy organization, but as such effusions are not always, or even generally, ateifded with'this consequence it is P™^^"^^™^ to" modification of the nutritive function, especially as this is known to be sufficient of it elf to produce the effect independently of inflammatory acfion The most remarkable examples of softening occur in the lungs, ple'en mucous membranes of the stomach and bowels, and in the brain 500 HUNTER ON THE BLOOD. and spinal marrow. The original organization in such cases is often irrecoverably destroyed. Fragility must not be confounded with softening, although it is often found associated with it. An increased lacerability of parts is, upon the whole, much more general than softening, and occurs under both the conditions which have previously been considered. It is seen in the inflamed and hepatized lung, as well as in the common cellular membrane which has been hardened by the infiltration of recent lymph. Hypertrophy consists in the undue development of parts beyond their normal proportions. Like every other change consequent on inflammation, hypertrophy may occur from other causes besides inflammation, because inflammation merely alters the nutrition of parts, which many other causes are equally capable of doing. It is always associated with a state of hyperemy, and most frequently with increased density of structure. When it arises from simply increased functions there seems to be no difference in the mode of growth from that of ordinary nutrition; but when it arises from inflammation the augmentation of bulk is effected by interstitial deposition, which afterwards becomes organized. In hypertrophy of the bladder, consequent on diseases of this part, both these causes concur to produce the effect; these distinctions, however, are not always apparent, especially in bones, which often enlarge under circumstances which fall short of inflammation, and yet are more or less connected with it. Exostoses, for example, which are partial hypertrophic developments, are often traceable to mechanical injuries; and in the same manner bones are often found to enlarge from constitutional causes, as gout, rheumatism, syphilis, &c, which in a more active form produce inflammation. A chronic ulcer of the surface may occasion an enlargement of the bone beneath, and a similar effect may be produced by the Barbadoes leg. Atrophy is a vice of nutrition, the very reverse of the former. Both appear to have their analogies in the evolution of the foetus, in which there is sometimes an arrest and sometimes a persistence of the formative principle, giving rise to two opposite forms of monstrosity. As in inflammation, therefore, the principle of growth or augmentation of parts, which seems natural to this state, is sometimes persistent beyond the due and regular period, so on the other hand the principle of absorption, by which this excess of growth is removed, is sometimes continued after the due and regular effect of the restoration of the parts to their natural condition has been accomplished. The excess of growth in an inflamed part being useless when the inflammation has subsided, and perhaps an incumbrance to the due exercise of its functions, is removed on the same principle as many parts, having a temporary use in foetal life, or pans in the adult which have become disorganized and unfit for their office, are got rid of; for in general it may be observed that the use of a part, and consequently its necessity, are the only protection which it has against the operation of this law. Accordingly, it is observed that those parts which have only a temporary use in the economy, as the testi«les, mammas, ovaries, etc., are most liable to the effect of wasting, in consequence of inflammatory action. The secondary effects of inflammation, or those which regard the organical constitution of parts, are coextensive with the whole range of pathology, and cannot be entered into in this place. The most general division of these formations is into the analogous, or those which have BIBLIOGRAPHY OF INFLAMMATION. 501 some analogy in the healthy body, and the heterologous, or those which have no resemblance to any healthy elementary tissue, as schirrus, melanosis, tubercle, &c, and which therefore are to be regarded in the highest sense as morbid productions. The former again have been subdivided by Heusinger into new or analogous formations, or accidental, parasitical, and adventitious tissues anormally developed in situations where they did not previously exist, as serous cysts, fatty tumours, &c.; and analogous transformations, or the conversion of existing parts into structures of a different kind from that which they originally possessed, as when serous and fibrous membranes are converted into bone, muscle into fat, &c. The former are nearly as extensive as the natural elementary tissues of the body, and, for the most part, are injurious. The latter are less numerous, being sometimes characterized by an elevation of the natural organization ofthe part, to answer some new and useful object in the economy, and sometimes, by a degradation of the original tissue, subversive of its peculiar function. In the opinion of many modern physiologists, the whole of these anormal productions are referrible to an inflammatory cause ; and undoubtedly such a cause, or some external injury almost equivalent to it, may often be detected in many individual cases ; but still this is very far from being general, and therefore, for reasons which I have previously given (Prin. of Surg., p. 150, note), I cannot concur in this opinion. Inflammation appears to produce morbid growths ; first, by weakening the parts ; and secondly, by inducing a temporary modification of the normal mode of nutrition, both which circumstances are the invariable consequents of inflammation, and may reasonably be presumed to predispose the affected parts to assume a new disposition, corresponding to any preexisting cause of disease which may be in the constitution at the time. Without the concurrence of some other cause, however, inflammation alone is insufficient for the effect, and when this cause actually exists inflammation is unnecessary, and the remedies for inflammation unavailing.

BIBLIOGRAPHY OF INFLAMMATION.

♦ See p. 138 for the ^^^ are here merely referred to. It may be F^ fa therefore seldom inserted tSK^ptr toTeS1&ZZ&W*. on pabular «bj*. 4o 502 HUNTER ON THE BLOOD. chef, J. L. Del'Emploi de l'Opium dans les Phlegmaisies des Memb. Muqueuses, sereuses et fibreuses, &c. 8vo. 1828.----Bricheteau, in Diet, des Sc. Med., Art Inflammation et Phlegmasie.----*Broussais, F.J. V. Hist, des Phlegmasies, &c. 2 tom. 8vo. 1808; and Hist. des Phlegmasies Chroniques, 3 tom. 8vo. 1822 ; and 4eme edit. 3 tom. 8vo. 1826. tr. by Hays. Phil. 1831.----Brown, J. Med. Essays on Fever, Inflam., &c. 8vo. 1828.----Burdach, K. F. Diss. Observ. nonnullae Microsc. Inflam. spectantes 1825; and op. cit. (v. a. p. 139.) ----Burns, J. Diss, on Inflamm. 2 vols. 8vo. 1800 ; and Principles of Surgery, vol. i. (p. 24.) 8vo. 1831.

Caffin, J. F. Du Caractere de I'lnflam., de la Congestion, &c. 8vo. 1819. ----Caffort. Memoir sur la Nature de I'lnflam. 8vo. 1829.----Carpue. J. C. An Account of two successful Operations for restoring a lost Nose, &c. 4to. 1816.----Carus, C. G. De Vi Naturae Medicatrice in formandis Cicatricibus. Part i. 8vo. 1822.----Chaufford, H. Traite des Inflam. Internes. 8vo. 1831.----Chomel, in Diet, de Med., Art. Inflam. tom. xii. 1825.----Chortet, J. F. Traite de I'lnflam. et de ses Terminaisons. 8vo. 1808.----Coxe, J. B. (Th.) On Inflam. Phil. 8vo. 1794.----Crawford, and Tweedie, Drs., in Cyclopaedia of Pract. Med., Art. Inflam. vol. ii. 1832.----Cruveilhier, J. in Diet, de Med. et Chir. Prat., Art. Adhesion. 1829.----Cullen, TV., M.D. First Lines, etc. (vol i.) 4 vols. 8vo. 1789.

Delpech, J. Precis Elem. des Mai. Chir. (tom. i. c. i.) 3 tom. 8ve, 1816. ----Dohlhqf. De Phlegmone. 8vo. 1819.----Dowler, T., op. cit. (v. a. p. 140.) On the Products of Acute Inflam.----Duges, A. Essai Phys-Path. sur la Nature de la Fievre, de I'lnflam., &c. 8vo. 1823. ----Dzondi, H. C. Aphorismi de Inflam. lib. i. 8vo. 1814.---- Dzondi, K. H. Pathologia Inflammationis. 8vo. 1828.

Earle, J. TV., in Med. Gaz., vol. xvi. 1834-5. On Inflam.----Edden, H. A. Die Theorie der. Entzundung. 8vo. 1811.----Eggers. Von der Wiedererzeugung. 8vo. 1821.----Emiliani, L. Dell' Inflam. Comm. 8vo. 1824; and Ricerche sul trattamento delle Malattie Inflammatorie. 8vo. 1829.

Fegelein, G. M. Versuch einer Nosologie und Therapei der Entzundungen. 8vo. 1804.----Filippi, G. de. Nuovo Saggio Analitico sull' Inflam.

*Gendrin, op. cit. (v. a. p. 141.)----Gerardin, Essai sur les Phlogoses Sarcopee et Osteopee, &c. 4to. 1823.----Gibson, TV., M.D. The Institutes and Practice of Surgery, &c. 2d edit. 2 vols. 8vo. Phil. 1827. ——Goeden, H. A. Die Theorie der Entzundung, 8vo. 1811.---- Goldoni, A. Sulle inflam. trattato diviso in tre parti, pt. i. 1825.— Discorso in risposta alle cose a su riguardo stampata dal Sig. Prof. G. Tommasini nel vol. ii. sull' inflam. 8vo. 1829.----Good, J. M., M.D. Study of Med. (ii. 283.) 3d edit, by S. Cooper. 5 vols. 8vo. 1829. ----Graefe, R. C. F. De Rhinoplatice, &c. Lat. edidit J. F. C. Hecker. 4to. 1818.----Gruithuisen, Fr., in Gaz. Med.-Chir. de Salzbourg. ii. 129. (1816.)—Theorie der Entzundung. ib. ii. 298. (1811); and Preface to his Organozoonomie. 8vo. 1811. BIBLIOGRAPHY OF INFLAMMATION. 503 Harles, J. C. F. Pratische Bemerkungen uber innere Entzundungen bey Kindern. 4to. 1810.----*Hastings, C, M.D., op. cit. (v. a. p. 228.) ----Herdman, J. Diss, on White Swelling and the Doctrine of Inflam. 8vo. 1802.----Heffter, D. F. Doctrinae de Gangrena Brevis Expos. 4to. 1807.—On the subject of hospital gangrene consult Larrey, O'Halloran, Delpech, Hennen, and the military surgeons generally. See also Reuss and Plouquet, Art. Gangrene and Sphacelus.----Henke, A. De Inflam. internis Infantum comm. 1817.----Hermann, De Inflam. in Genere.----Hildenbrand, J. V. N. Instit. Pract.-Med., &c. (ii. De Inflam.) 4 tom. 8vo. 1816-25.----Hoffmann, C. R. Sententia de Inflam. Natura. 8vo. 1819.----Hofrichter, B., Versuch uber das Entzundungsfieber und die Entzundung. 8vo. 1806.----Hohnbaum, uber das Fortschreiten des Krankheits-processes insbesondere der Entzundung., &c. 1826.----Hunt, J. On the Progress of Medical Science regarding Inflam., Gangrene, and Gunshot Wounds. 4to. 1801.

*James, J. H. Observ. on the General Principles, &c. of Inflammation. 8vo. 1821. 2d edit. 1832.

Lalanne, P. quelques Consid. sur I'lnflam. en general et sur les differentes terminaisons. 4to. 1804.----Langenbeck, C. J. M. Nosologie, &c. der Chir. Krankheiten (1. 6.) 3 bde 8vo. 1822-25.----^Lawrence, TV. in Med. Gaz. vol. v. p. 97. 1829-30. Lect. on Surgery.---- Liesseling, C. L. G. de Gangraena, 4to. 1811.----Lizars,J. in Edin. Med. and Sur. Journ. xv. 369. (1819.) On the Pathology ofthe Nerves in Inflam.----Lobstein, J. F. Traite d'Anat. Path. (§ 334.) 8vo. et fol. 1829.____Lucas, C. E., M.D. The Principles of Inflam. and Fever. 8vo. 1822.

Magenisie, D. The Doct. of Inflam., &c. 8vo. 1768—-Mantavoni V Lezioni di Nosologia e terapia sulle Inflam. (vol. m.) 12mo. 1820. —-Meier J Versuch einer kritsche Geschichte der Entzundung 8vo 1812.1—Meyer, Im. ueber die Natur. d. Entzundung. 8vo..1810' ____Versuch e. krit. Geschichte d. Entzundung. 8vo. .1812.—- Moore, J. Diss, on the Process of Nature in filling up^avitiej.. healing of Wounds, &c. 4to. 1789.----Morgan, G. T. on Inflam. and its Effects. 8vo. 1837.

Naumann, M. zur Lehre von der Entzundung, 12mo 1828—iV^cA, K. F. ueber verborgene Entzundung. &c. 8vo. 1819.

Parru C H., M.D., Elem. of Path, and Therap.Svo. 1815 and op. cit. ZK n 229 t—iW, Fr. Comm. Phys. Chir. de Vulnenbus sa- ^ l: ?s 111 lft25____Porret, S. (Th.) Apercu sur les Phenomenandis, &c. 4to. 1«£- consideres dans les differens Systemes. 8vo. nes g.enerau^e/],nX'ographie Phil., &c. (torn. ii. Phlegmasie,) sVm.TsTsTana'6me edit.S "torn. 8vo. 1818.—Plouquet. Diss, de 504 HUNTER ON THE BLOOD. multifariis Inflam. Terminationibus. 4to. 1803.----Portel, P. J. P. Diss, sur I'lnflam. 4to. 1803.----Prevost, J. L. in Mem. de la Soc de Phy. de Geneve, vi. 142. (1833.) note sur I'lnflam.----Prus. de l'lrritation et de Phlegmone. 8vo. 1825.

Roche, in Diet, de Med. Prat. art. Inflam. vol. x. 1833.----Ronnefeld, C. H. Animadv. nonnullae ad Doct. de Inflam. 4to. 1817.----Rogerson, G. A Treatise on Inflam. vol. i. 8vo. 1832.

Salfender. Diss, de Reunione Partium Corp. Hum. Elementarium. 8vo. 1826.----Sanson, L. J. de la Reunion Immed. des Plaies, &c. 8vo. 1834.—t—Scholefield, de Theoria Inflam. 1822.----Scott, J. Surgical Observ. on the Treatment of Chron. Inflam. in various Structures, &c. 8vo. 1822.----Serre, M. Traite de la Reunion Immediate, &c. 8vo. 1830____* Smyth, J. C. M.D., Ofthe different Kinds and Species of Inflammation, and of the Causes to which these Differences may be ascribed : in Med. Communications. (1790.) II. 168.----Somme. Etudes sur I'lnflam. 8vo. 1830.----Sporer, G. M. de Inflam. Morbo Anim. et Veget. 1824.----Stahl, G. E. Diss, de Inflam. vera Pathologia. 4to. 1698.----Stevens, A. H. A Diss, on the proximate Causes of Inflam. 8vo. 1811.----Suchs, L. TV. Grundlinien zu einem Systeme der pratische Medicin. (Th. 1. Entzundungen.) 8vo. 1821.---- Suringar. Comm. Med. de Modo, quo Natura versatur in restituendo omni quod in Corp. Hum. solutum sit. 4to. 1823.----Syme, J., in Edinb. Med. and Surg. Journ. vol. xxx. (1828.) p. 316. On the Nature of Inflam.

^Thomson, John, M.D. op. cit. (v. a. p. 144.)——Tommasini, G. Dell' Inflam., &c. 8vo. 1820. and 2da ediz. 2 vol. 8vo. 1820-7.—— Travers, B. Inquiry into the Disturbed State of the Vital Functions, called Constitutional Irritation. 8vo. 1826.—Further Inquiry, &c. 8vo. 1835.

*Vacca,L. Liber de Inflam. Morbosae, quae in Humauio Corpore fit, Natura, Causis, Effectibus, et Curatione. 1765.

Waring, (Th.) de Inflam. 1823.----TVedemeyer, V. G. Untersuchungen uber des Kreislauf des Blutes. 1828.----Wendelstedt. Diss, de Cognatione et Differentia inter Inflam. et Profluvia. 1809.____TVendt G. Die alte Lehre von den Verborgenen Entzundungen bestatigt. 2te Aufl. 8vo. 1826.----White, in Mem. ofthe Soc. of Manchester, vol. i. (1785.) On the Regen. of Animal Substances.----Wiesmann, J. H. F., de Coalitu Partium a reliquo Corpore prorsus disjunctarum Comm., etc. c. tab. aen. 4to. 1824.----Willis, J. C, (Th.) de Inflam., 1802. ----Wilson, J., op. cit. (v. a. p. 145.)----*Wilson, Philip, M.D., on Febrile Diseases, 8vo. 1799, and 4th edit. 8vo. 1820, and op. cit. (v. a. p. 231.)----Winterl. J. J. Inflam. Theoria Nova. 8vo. 1767.

For a further account of the literature of this subject, particularly of specific inflammations and of the opinions of the older authors, consult the undermentioned works :

Suppuration and Ulceration.

Abernethy, J. Obs. on Tumours and Lumbar Abcesses. 8vo. 1810.- Andral (I. 189. De l'Ulceration, I. 388. Pus), ut supra.----Balfour, J. H. Probationary Essay on Purulent Deposits after Wounds and Operations. 8vo. 1833.——Bell, B. and 7.,^ supra.----Blackadder, H. H. on Phagadaena Gangrenosa. 8vo. 1818.----Brande, T. TV. In Phil. Tr. 1809. p. 373.----Brugmanns,S. 7. De Puogenia, &c. 8vo. 1785.----Callisen, H. System der Neueren Chir. 1822. p. 559, note. ----Cooper, Sir A. Lectures on Surg., by F. Tyrrell, (vol. i. p. 35.) 3 vol. 8vo. 1824-7.----Daucher. Momenta circa variam Puris Indolem, &c. 1804. Diet, des Sc. Med. (Petit.) Art. Depot,—Diet, de Med. (Roux) Art. Abces.—Diet, de Med. et Chir. Prat. (Dupuytren) Art. Abces.—Cycl. of Prat. Med. (Tweedie) and Encycl. Worterb. (Richter) Art. Abscess.----Dupuy, J. M. Sur les Abces ou Tumeurs Purulentes. 1804.----Encycl. Meth'o. Art. Abces.----Ford, Ed. Obs. on the Dis. of the Hip-joints (Chapter on Abscesses), 8vo. 1794.----Goebel, in Schweigger's Journ., vol. iv. part iv. p. 408.----Grashuis, J. Diss. on Suppuration. 8vo. 1747.----Gruithuisen, P. Untersuchung uber den Unterschied zwischen Eiter und Schleim durch das Mikroskop. 4to. 1809. with Engr.----Hendy, J. Ess. on Glandular Secretion containing an exp. Inq. into the formation of Pus. 8vo. 1775.----Hoffmann, Sententia de Supp. Natura. 8vo. 1818. Home, Sir E. on the properties of Pus. 4to. 1788.----Phil. Tr. 1819. p. 1. on the Conversion of Pus into new Flesh,—also on Ulcers of the Legs. 8vo. 1797. 2d edit. 1801.----Kaltenbrunner, G. in Heusinger's Zeitschrift f. Organ-Physik. vol. i. Pt. III. p. 314.----Koch, ut supra.----Kupfer, H E de Inflam. et. praesertim de Puris Generatione. 1828.----Lanzenbeck, J. M. in neue Bibl. fur die Chir. 12mo. 1817.—also his de Diagnosi Puris. 1827.----Pramann, A. de puris Indole et Genesi. Svo 1828.----Quesnay, F. Traite de la Supp. 12mo. VIJQ.-— Richter, A. G. Anfangsgrunde der Wundarzneykunst (b 1. Kap.2.), 7 bde 8vo 4te Aufl. 1804-25.----Rizzetti, Rossi and Michelotti, in Med. de Turin, vol. ii. and iii.----Waldmann, Disquisitiones de Discrimine inter Pus et Pituitam. 1807.

On the Effects of Inflammation on Texture.

Andral, (I. 91-298,) ut supra.----Boullaud, A. in Journ. des Prog. 506 HUNTER ON THE BLOOD. des Sc. Med. iv. 149. 1827. Rech. Hist, sur les Tissus Accikentels sans-analogues.----Bugayski, Diss, de Part. Corp. hum. solid, simil. Abberrationibus. 4to. 1813.----Carswell, op. cit. (v. a. p. 139.) Fasc. xi. analogous tissues.----Clarus, A. Quaestiones de Partibus Pseudo- Organicis. 8vo. 1805.----Cruveilhier, op. cit. (v. a. 140.)----Diet. Abrege des Sc. Med. Art. Anat., Path., par MM. Bayle et Boisseau. ----Dumas, C. L. in Sedillot's Journ. Gen. xxiii-xxv. sur les Transformations des Organes.----Gisbert Van Beers, de Textura Organorum per Inflam. 1826.----Hesse, ueber die Erweichung der Gawebe und Organe des menschl. Corpers. 8vo. 1827.----Heusinger, System der Histologie, Pt. I. p. 87-103. 4to. 1822. and in the first Berichte von derKonigl. Anthropotomischen Anstalt zu Wurzburg, p. 1-41. 4to. 1826.-----Junge, de Pseudo-Plasmatum in Corp. Hum. obviorum natura et Indole. 4to. 1822.----Laennec, R. T. H.'mJournal de Med. de Corvisart. XI. 360. and Diet, des Sc. Med. vol. ii. Art. Anat. Path.----Martin, in Mem. de la Soc. Med. d'Emulation. vii. on Organic Diseases.----Meckel, J. F. op. cit. i. 531. des Formations Accidentelles. (v. a. p. 229.)——Napple, (Th.) Sur les Fausses Membranes et Adherences. 1812.----Otto, A. TV. op. cit. (v. a. p. 231.)---- Villerme, Essai sur les Fausses Membranes. 4to. 1814.----Walther, in Journ. der Chir. vol. v. Pt. II. p. 196.----Wenzel, C. ueber dei Induration, &c. 8vo. 1815.

Aitkin, T. J. Essay on the Effects of Puncture received in Dissection. 8vo. 1826.----Baillie, in Lond. Med. Rep. 1826. on Inflam. of Cell. Tissue.----Butter, J., M.D. on Irritative Fever. 8vo. 1815.---- Creutzwieser, in Rust's Magaz. f. d. Ges. Heilk. xxii. Pt. II. 338. Necrosis Telae Cellulosae.----Craigie, D. (Path. Anat. p. 32.) ut supra.----Dohlhof, D. de Phlegmone. 8vo. 1819.----Duncan, A. M.D. in Edin. Med. and Chir. Tr. vol. i. 1824. on diffuse Cellular Inflam.----Kirkland, T., M.D. An Inquiry into the present state of Med. Surgery, (ii. 282.) 2 vols. 8vo. 1783.----Naumann,D. De Inflam. Telae Mucosae. 1820.----Otto, (p. 91.) ut supr. and Selt. Beob. Pt. II. p. 41.----Pauli, in Rust's Magaz. f. d. Ges. Heilk. (1828) xxvii. 128.----Scott, in Edin. Med. and Surg. Journ. xxiv. 225. on Diffuse Cellular Inflam.----Testa, A. J. inRoemer Dissert. Med. Ital. 8vo. note, de Cellulosae Telae Affectibus.----Travers, ut supra.

Alibert, J. L. Descriptions des Maladies de la Peau. 8vo. 1816. and fol. 1,825. Monograph, des Dermatoses. 4to. 1832.----Bateman, Th., M.D. A Practical Synopsis of Cutaneous Diseases. 8vo. 1813-14. 6th edit. 1824. with Atlas of Delineations 1817, by Dr. A. T. Thompson, roy. 8vo. 1829.----Craigie, (Path. Anat. p. 604.) ut'supra.----Danzer, Synopsis der Hautkrankheiten. 1808.----Hutchison, C. in Med. Chir. Tr. v. 278. and xiv. 213. on Erysipelas.----Kieser, uber das Wesen und die Bedeutung der Exantheme. 1812.----Lawrence, TV. in Med. Chir. Tr. xiv. 1. on Erysipelas.----Lorry, A. C.De Morbis Cutaneis Tractatus. 4to. 1777.----Marcus, A. F. Die Exantheme ihre Er- BIBLIOGRAPHY OF INFLAMMATION. 507 kenntniss und Heilart. 1812.----Meckel, (p. 472,) ut supra.----Nasshard, Skizze einer Dermatopatbologie. 1816.----Otto, (p. 117,)w* sup.----Plenck, J. J. De Morb. Cut. &c. Edit. 2da. 8vo. 1783.---- Plumbe, S. on Diseases of the Skin. 8vo. 1824. and 2d edit. 1827.---- Rayer, P. Traite The. et Prat, des malad. dela Peau. 2 t. 8vo. 1826-7. and 2eme edit. 3 tom. 1835.fr. by Dr. Willis 8vo. 1835.----Serre, M. Nouveau Traitement Special d'Abortif de I'lnflam. de la Peau. du Tissu Cellulaire, &c. 8vo. 1837.----Turner, D. Treatise of Diseases incident to the Skin, &c. 8vo. 1723. and 4th Edit. 4to. 1731.----Willan, R., M.D. Description and Treatment of Cutaneous Diseases. 4to. 1798-1808.

Abercrombie, J., M.D. Path, and Prac. Researches on the Stomach, &c. 8vo. 1828.----Bichat, X. Traite des membranes en general, &c. 8vo. 1802; tr. by J. Houlton, 8vo. 1838; and Anat. Gen. supra cit. (v. a. p. 138.)----Billard, C. De la Memb. Muquese gastro-intest. dans l'etat sain et dans l'etat inflam. 8vo. 1825.----Bretonneau, P. Rech. sur I'lnflam. special du Tissu Muqueuse. 8vo. 1826.----Caba- 7iis, P. J. G. Observ. sur les Affections Catarrhales en general, 2de edit. 8vo. 1813.----Craigie, D. (Path. Anat. p. 667,) sup. cit.; and Practice of Physic, vol. i. (p. 727.) 8vo. 1836.----Franc, ab Hildenbrand, (Th.) De Catarrhis. 4to. 1812.----Hastings, ut supra.---- Hodgkin, F„ M.D. Lectures on the Mucous and Serous Membranes, vol. i. 8vo. 1837.----Lejeune, (Th.) Inflam. du Systeme Muqueux. 4t0. 1806.----Lelut, in Repert. Gen. d'Anat. et de Phys. Path. iii. P. i. p. 145, sur le Muguet.----Otto, (p. 101, ut supra.----Meckel, (p. 502, du Systeme Cutane Interne, etat anormal,) ut supra.

Andral, (ii. 569, Maladies du Tissu Cellulaire et Membranes Sereuses,) ut supra.----Belmas, D. Recherches sur un moyen de determiner des Inflam. adhesive dans les Cavites Sereuses. 8vo. 1831.----Brodie, Sir B. On the Joints, (ch. i. ii. iii., on Diseases of the Synovial Memb.; and ch. ix., on Inflam. of the Bursa? Mucosas) 3d edit. 8vo. 1834____Chomel, D. F. sur le Rheumatisme, 1813.----Cloquet, J. In Archiv. Gen., de Med. sur les Ganglions.----Craigie, (Path. Anat. np 759, 807. ut supra.----Herwig, D. De Morbis Bursarum Mucosarum. 4to. 1795.----Koch, De Morbis Bursarum Tendinum Mucosorum. 1790; and Untersuchung des naturl. Baues und der Krankheiten der Schleimbei.tel.8vo. 1795—Lahalle, ( Th ) sur 1 Inflam. du Systeme Sereux. 8vo. 1802.----Lorich, De S.gnis Inflam. Memb Serosarum 4to. 1812.----Meckel, (i. 448., du Systeme Sereux, etat tnorZ\Tnt npra.----Moffait, Sur les Phlegmasies des Memb. Syn™.LArXations. si 1810.—Otto, (pp. 97 873:,)ut supra. ■Rnche Phlegmasies du Syst. Fibro-sereux des Articulations. 4to. T^o" SauvemDe la Villeroye, J. T. Essai sur les Inflam. du SvsemTstufet du Systeme Synovial. 4to. 1812.—Villerande, % In Fosse Dis. sur Rheumatisme. 1815.----Zinc, In Jour. Comp. u^ Die des Sc.Ved. xxi. 24. sur les Fungus des Memb. Sereuses. 508 HUNTER ON THE BLOOD. Fibrous Tissue.

Craigie, (Path. Anat. pp. 505, 511,) ut supra.----Crampton, P. In Dubl. Hosp. Reports, i. 337, 397.—On Periostitis.----Gotz, G. De Morbis Ligamentorum, 4to.----Huhn. De rite cognoscenda et curanda System. Fibr. Inflam. 8vo> 1820.----Meiselbach. De Periostei Inflam. 8vo. 1824.----Otto, (pp. 233, 255,) ut supra.----Rayer, In Arch. Gen. de Med. for Mar. et Apr. 1823.

Osseous and Cartilaginous Tissue.

Bell, B. On the Diseases of Bones. 12mo. 1828.----Boyer, M. Le Baron, Lectures on the Diseases of Bones, tr. by Forrel, 2 vols. 8vo. 1804.----Breschet, S. (Th.) Sur la Formation du Cal. 4to. 1819. ----Brodie, ut supra, and Med. Chir. Tr. xvii. 239.----Charmeil, De la Regen. des Os. 1821.----Craigie, (Path. Anat. p. 551,) ut supra.----Cruveilhier, In Arch. Gen. de Med. Feb. 1824. p. 161. ----Flormann, De Inflam. Ossium. 1799.----Goetz, De Ostitide. 1822.----Howship, I. In Med. Chir. Tr. vi. 263. vii. 387-581. viii. 57. x. 176; on the Morbid Appearances and Structure of Bones.---- Knox, In Edinb. Med. and Surg. Journ. 1822,1823.----Koeler, G. L. Exper. circa Regenerationem Ossium. 8vo. 1786.----Mayo, H. In Med Chir. Tr. vol. ii. 104, on Ulcer, of the Cartilages.----Meckel, (p. 327,) ut supra.----Naumann, A. F. De Ostitide. 4to. 1818.---- Otto, (p. 145,) ut supra.----Petit, J. L. Traite des Maladies des Os, 2 tom. 8vo. 1723.—Le meme, revu et augmente, par Louis, 2 tom. 12mo. 1784.----Sanson, J. L. Expose de la Doct. de Dupuytren, sur le Cal, in Journ. Univ. des Sc. Med. xx. 131.----Scarpa, A. De Anatome et Pathologia Ossium. 4to. 1827.----Scavini, J. M. Observ. sur une Exostose particuliere produite de cause externe, &c. 8vos1810. ----Schramm, De Oss. Inflam. 1805.----Syme, Jas. On Necrosis. 8vo. 1823.----Weidmann, J. P. De Necros'i Ossium, fol. 1793.---- Wilson, J. Lect. on the Bones, &c. 8vo. 1820.

Craigie, (Path. Anat. p. 493,) ut supra.----Otto, (pp. 250, 281,) ut supra, and in Selt. Beob. part II. 40.----Plouquet, De Myostitide et Nevritide. 1790.

Abernethy, J. Surg, and Phys. Essays, part II. 8vo. 1793-7.----Alard, De I'lnflam. des Vaisseaux Absorbens, &c. 2de edit. 8vo. 1824.____ Arnott, J. M. In Med. Chir. Tr. xv. p. 1; a Pathological Inquiry into the Secondary Effects of Inflam. of the Veins.----Breschet, In Journ. Comp. du Diet, des Sc. Med. ii. 325.----Bright, op. cit. (v. a. p. 139.)----Brodie, Sir B. C. In Med. Chir. Tr. viii. 195.---- Carmichael, Observ. on Varix and Venous Inflam.----Craigie, (Path. Anat. p. 88, 128, 143,) ut supra.----Fedeli, F. De Lymphangiotide. &c. 8vo. 1825.----Fricke, Annalen des Hamburger Krankenhauses. OF GUNSHOT WOUNDS. 509 1826, with plates.----Guthrie, In Lond. Med. and Phys. Jour., July 1826.----Hodgson, J. On Diseases of the Arteries and Veins. 8vo. 1815.----Lee, R., M.D. In Cyc. of Pract. Med., Art. Veins; and Med.-Chir. Tr. xv. 132, 369.----Locatelli, B. De Angiotide, &c. 1828.----Longuet, (Th.) Inflam. des Veines, 4to. 1815.----Osiander, Neue Denkwurdigkeiten, i. p. 57.----Otto, (p. 327, Arteritis ; p. 345, Phlebitis; p. 358, Inflam. of Lymphatics,) ut supra.----Ribes and Bouillaud, In Rev. Med. Fran, et Etrang. ii. 71, 448, and iii. Pt. iv. and vi.----Sasse, De Vasorum Sang. Inflam. 1797.----Schmuck. De Vasorum Sang. Inflam. 1793.----Schwilgue, In Bibl. Med. xvi. 194; Hist, des Inflam. des Veines.----Spangenberg, In Horn's Archiv. fur Med. Erfahrung. 1804. v. 269. Ueber die Entzundung der Arterien.----Testa, A. J. Delle Malattie del Cuori, 3 vols. 8vo. 1826. ----Trovers, B. On Wounds and Ligatures of Veins, in Essays, by Cooper and Travers, part i. p. 227. 8vo. 1818.----Velpeau, In Arch. Gen. de Med. for Oct. 1824.

Abercrombie, J., M.D. Research, on the Dis. of the Brain and Spinal Cord. 8vo. and 2d edit. 1829.----Bayle, G. L. Traite des Maladies du Cerveau, &c. 8vo. 1826.----Craigie, (pp. 281, 376,) ut supra.---- Graf. De Myostitidis Nosographia. 4to. 1823.----Hooper, R., M.D. The Morbid Anat. ofthe Human Brain, 4to. 1826.----Klohss, K. L. Diss.de Myostitide. 8vo. 1820.----Lallemand, F. Rech. Anat.-Path. sur l'Eucephale, &c- 8vo. 1824-9.----Mortinet, L- Mem. sur I'lnflam. des Nerfs. 1824; and Rev. Med. ii. 329, 354.----Ollivier, C. P. De la Moelle Epiniere et de ses Maladies. 1824.----Otto, (pp. 407, 437, 452, ut supra.----Pinel, P. in Journ. de Phys. i. 54. sur I'lnflam. de la Moelle Epiniere.----Rostan, L. N. Rech. sur la Ramollissement du Cerveau. 8vo. 1820. and 2de edit. 8vo. 1823----Velpeau, M. A. In Areh- Gen. de Med. vii. 52, 329, (1825,) Mem. sur une Alteration de la Moelle allongee, &c. PART IV. CHAPTER I..

Gunshot wounds may be said to be an effect of a modern improvement in offence and defence, unknown in the former mode of war, which is still practised where European improvements are not known; and it is curious to observe that fire-arms and spirits are the first of our refinements that are adopted in uncivilized countries; 510 HUNTER ON THE BLOOD. and, indeed, for ages they have been the only objects that have been at all noticed or sought after by rude nations. It was not till the fourteenth century that gunpowder was made, or rather compounded; but it was not till afterwards applied to the purpose of projecting bodies. But even now the wounds received in war are not all gunshot wounds: some, therefore, are similar in many respects to those received in former times. The knowledge ofthe effect of gunpowder, and its application to the art of war, dr the projection of bodies for the destruction of men, has been in some degree accompanied by improvements in the arts and sciences in general, and among others that of surgery, in which art the healing of wounds so produced makes a material part. In France, more especially, the study of both were carried to considerable lengths; but though the art of destruction has been there improved and illustrated by writings, it is rather surprising that the art of healing should not have been equally illustrated in the same manner.* Little has been written on this subject, although perhaps, when we take every circumstance into consideration, it requires particular discussion ; and what has been written is so superficial that it deserves but little attention. Practice, not precept, seemed to be the guide of all who studied in this branch; and if we observe the practice hitherto pursued, we shall find it very confined, being hardly reduced to the common rules of surgery, and therefore it was hardly necessary for a man to be a surgeon to practice in the army.

§ 1. The difference between Gunshot Wounds and common Wounds.

Gunshot wounds are named, as is evident, from the manner in which they are produced; from the frequency of their happening in the time of battle to a set of men appropriated for war, both by sea and land: and from the appointment of particular surgeons for their cure, they have been considered apart from other wounds, and are now become almost a distinct branch of surgery. Gunshot wounds are made by the projection of hard, obtuse bodies, the greatest number of which are musket-balls ; for cannonballs, pieces of shells and stones from ramparts in sieges, or splinters of wood, etc., when on board of a ship in an engagement at sea, can hardly have their effects ranked among gunshot wounds; they will come in more properly with wounds in general. As the wounds themselves made by those very different modes will in general differ very considerably, any peculiarity that may be necessary in the treatment of gunshot wounds from those made by can-

* [The illiberality of this sarcasm has been amply atoned for by the judicious Hennen, who, in his " Introductory Remarks" to Military Surgery, has not scrupled to assign the chief rank to the military surgeons of France, previous to the time of Hunter, at the same time that he pays a well-deserved compliment to the admirable " Memoirs ofthe French Academy of Surgery," which were published in 1743-57.—Principles of Military Surgery, by John Hennen, M.D., p. 12.] OF GUNSHOT WOUNDS. 511 non-balls, shells, etc., or even common wouns, will generally belong to those made by musket-balls. The whole of gunshot wounds will come within the definition of accidents. They are a recent violence committed on the body, but they often become the cause of, or degenerate into, a thousand complaints which are the objects of surgery or physic, many of which are common to accidents in general, and to many other diseases. Of this kind are abscesses, ulcerating bones, and fistulas; but some are peculiar to gunshot wounds, as calculi in the bladder from the ball entering that viscus, consumption from wounds in the lungs, which I believe rarely happens; for I cannot say I ever saw a case where such an effect took place. But it is the recent state in which they are distinguished, and in which they are to be considered as a distinct object of treatment. Wounds of this kind vary from one another, which will happen according to circumstances: these variations will be in general according to the kind of body projected, the velocity of the body, with the nature and peculiarities of the parts injured. The kind of body projected, I have observed, is principally musket-balls, sometimes cannon-balls, sometimes pieces of broken shells, and very often, on board of ship, splinters of wood. Indeed, the effects of cannon-balls on different parts of the ship, either the containing parts, as the hull ofthe ship itself, or the contained, are the principal causes of wounds in the sailor; for a cannon-ball must go through the timbers of the ship before it can do more execution than simply as a ball, (which makes it a spent ball,) and which splinters the inside ofthe ship very considerably, and moves other bodies in the ship, neither of which it would do if moving with sufficient velocity; musket or cannon-balls seldom doing immediate injury to those of that profession. The wounds produced by the three last bodies will be more like many common and violent accidents, attended with much contusion and laceration of parts. Gunshot wounds, from whatever cause, whether from a musketball, cannon-ball, shell, etc., are in general contused wounds, from which contusion there is most commonly a part of the solids surrounding the wound deadened, as the projecting body forced its way through these solids, which is afterwards thrown off in form of a slough, and which prevents such wounds from healing by the first intention, or by means of the adhesive inflammation, from which circumstance most of them must be allowed to suppurate. This does not always take place equally in every gunshot wound, nor in every part of the same wound ; and the difference commonly arises from the variety in the velocity of the body projected; for we find in many cases where the ball has passed with little velocity, which is often the case with balls even at their entrance, but most commonly at the part last wounded by the ball, that the wounds are often healed by the first intention. Gunshot wounds, from the circumstance of commonly having a part killed in general do not inflame so readily as those from other 512 HUNTER ON THE BLOOD. accidents : this backwardness to inflame will be in the proportion that the quantity of deadened parts bears to the extent of the wound; from which circumstance the inflammation is later in coming on, more especially when a ball passes through a fleshy part with great velocity, because there will be a great deal deadened, in proportion to the size of the wound : therefore inflammation in gunshot wounds is less than in wounds in general, where the same quantity of mischief has been done ; and this also is in an inverse proportion to the quantity of the parts deadened, as I have already explained in my introduction to inflammation, viz., that inflammation is less where parts are to slough than where parts have been destroyed by other means. On the other hand, where the ball has fractured some bone, which fracture in the bone has done considerable mischief to the soft parts, independently of the ball, then there will be nearly as quick inflammation as in a compound fracture of the same bone, because the deadened part bears no proportion to the laceration or wound in general. From this circumstance, of a part being often deadened, a gunshot wound is often not completely understood at first; for it is at first, in many cases, impossible to know what parts are killed, whether bone, tendon, or soft part, till the deadened part has separated, which often makes it a much more complicated wound than at first was known or imagined ; for it very often happens that some viscus, or a part of some viscus, or a part of a large artery, or even a bone, has been killed by the blow, which does not show itself, till the slough comes away. If, for instance, it is a part of an intestine that has received a contusion so as to kill it, and which is to slough, a new symptom will most probably appear from the sloughs being separated, the contents of the intestine will most probably come through the wound, and probably the same thing will happen when any other containing viscus is in part deadened; but those cases will not be so dangerous as if the same loss had been produced at first, for by this time all communication will be cut off between the containing and contained parts: nor will it be so dangerous as when a considerable hlood-vessel is deadened ; for in this case, ■when the slough comes off, the blood, getting a free passage into the wound, as also out of it, probably death will immediately follow. If this artery is internal, nothing can be done; if in an extremity, the vessel may be either taken up, or probably amputation may be necessary to save the person's life; therefore an early attention should be paid to accidents where such an event is possible. In case of a bone being deadened an exfoliation takes place. Gunshot wounds are often such as do much mischief to vital parts, the effects of which will be according to the nature of the parts wounded and the violence of the wound; and also to parts, the soundness of which are essential either to the health of the whole, or to the uses of the parts wounded : such as some viscus, whose contents are voided through the opening or joints, the disposition of which is slow to heal, and whose uses are impeded when healed. OF GUNSHOT WOUNDS. 513 Gunshot wounds often admit of being classed with the small and deep-seated wounds, which are always of a particular kind respecting the cure. The variety of circumstances attending gunshot wounds is almost endless: the following case may be given as an example. An officer in the navy was wounded by a pistol-ball in the right side, about the last rib ; it entered about five inches from the navel and appeared on the inside of the skin about two inches from the spinal process, having passed in, I believe, among the abdominal muscles. The only remarkable thing that occurred was that the cellular membrane for some way about the passage of the ball was oedematous, and when I cut out the ball air came out with it.

§ 2. Of the different Effects arising from the difference in the Velocity of the Ball.

Many of the varieties between one gunshot wound and another arise from the difference in the velocity of the body projected; and they are principally the following. If the velocity of the ball is small, then the mischief is less in all of them, there is not so great a chance of their being compounded with fractures of the bones, &c.; but if the velocity is sufficient to break the bone it hits, the bone will be much more splintered than if the velocity had been very considerable, for where the velocity is very great, the ball as it were takes a piece out; however, all this will also vary according to the hardness of the bone. In a hard bone the splinters will be most frequent. When the velocity is small, the direction of the wound produced by the ball will in common not be so straight, therefore its direction not so readily ascertained, arising from the easy turn of the ball. When the velocity is small the deadened part or slough is always less ; for with a small velocity a ball would seem only to divide parts, while when the velocity is great the contrary must happen. From this circumstance it is that the slough is larger at that orifice where the ball enters than where it comes out; and if the ball meets with a great deal of resistance in its passage through, there will very probably be no slough at all at its exit, which will be therefore only a lacerated wound. . The greater the velocity of the ball the cleaner it wounds the parts; so much so as almost to be similar to a cut with a sharp instrument, from which circumstance it might be imagined that there should be a smaller slough. But I suspect that a certain velocity given to the best cutting instrument would produce a slough on the cut edges of the divided parts ; for the divided parts not giving way equally to the velocity of the dividing body, must of course be pro-

POGlmsho:t wounds are attended with less bleeding than most others; however, some will be attended with this symptom more than others, even in the same part. This arises from the manner in which the 44 514 HUNTER ON THE BLOOD. wound is produced. Bleeding arises from a vessel being cut or broken; but the freedom of bleeding arises from the manner in which this is done; if the artery is cut directly across, and it is done by a ball passing with a considerable velocity, it will bleed pretty freely; if bruised, and in some degree torn, then it will bleed less. When the velocity of the ball is small, the vessels will be principally torn, for they will have time to stretch before the continuity of their parts gives way; but if it is great they will bleed more freely, because velocity will make up for want of sharpness. According to the velocity of the ball so is the direction. When the velocity is great, the direction of the ball will be in general more in a straight line than when it is small; for under such circumstances the ball more easily overcomes obstructions, and therefore passes on in its first direction. Velocity in the ball makes parts less capable of healing than when it moves with a small velocity; therefore gunshot wounds in pretty thick parts are in general later of healing at the orifice where the ball enters than at the orifice where it passes out, because it becomes in some degree a spent ball, the part having less slough, being only torn, which will often admit of being healed by the first intention. In cases where the ball passes through, and in such a direction as to have one orifice more depending than the other, I have always found that the depending orifice healed soonest, and more certainly so if the ball came out that way, and also if the ball had been pretty much spent in its passage; therefore it will require art to keep the depending orifice open, if thought necessary. But this circumstance of its being a spent ball will not always happen; because if the person is near the gun when fired, the velocity of the ball will be very little diminished in its progress through the soft parts, and therefore it will have nearly the same velocity on both sides. This fact of the lower orifice healing soonest is common to all wounds, and I believe is owing to the tumefaction which generally arises from the extravasated fluid always descending to the lower part; and being retarded at the lower orifice, it is as it were stopped there, and presses the sides of the wound together, obliging it to heal, if the parts have not been deadened. This is evidently the case after the introduction of the seton in the hydrocele, especially if the two orifices of the seton are at some distance; but in the hydrocele there is a more striking reason for it, for in this disease the extravasated fluids are wholly detained about the lower orifice, as there is no depending part for the fluid to descend to.

§ 3. Ofthe different kinds of Gunshot Wounds.

Gunshot wounds may be divided into the simple and the compound. Simple, when the ball passes into or through the soft parts only; the compound will be according to the other parts wounded. The first species of compound are those attended with fractures OF THE TREATMENT OF GUNSHOT WOUNDS. 515 of the bones, or with the wound of some large artery. The second species of compound wounds is, where the ball penetrates into some of the larger circumscribed cavities. This last, or penetrating wound, may be doubly complicated, or may be divided into two. First, simply penetrating; and, secondly, where some viscus or contained part, as the brain, lungs, heart, abdominal viscera, &c, is injured; all which cases will be taken notice of in their proper places. CHAPTER II.

OF THE TREATMENT OF GUNSHOT WOUNDS.

It has been hitherto recommended, and universally practised by almost every surgeon, to enlarge immediately upon their being received, or as soon as possible, the external orifice of all gunshot wounds made by musket-balls. So much has this practice been recommended, that they have made no discrimination between one gunshot wound and another. This would appear to have arisen, and to be still continued, from an opinion that gunshot wounds have a something peculiar to them, and of course are different from all other wounds, and that this peculiarity is removed by the opening. I own that I do not see any peculiarity. The most probable way of accounting for the first introduction of this practice is from the wound in general being small, and nearly of a size from one end to the other ; also the frequency of extraneous bodies being forced into these wounds by the ball, or the ball itself remaining there; for the way in which these wounds are made is by the introduction of an extraneous body, which is left there, if it has not made its way through, so that the immediate cause of the wound makes a lodgment for itself, often carrying before it clothes, and even the parts ofthe body wounded, such as the skin, &c. From hence it would naturally appear at first view that there was an immediate necessity to search after those extraneous bodies, which very probably led the surgeon to do it; and in general the impossibility of finding them, and even of extracting them when found, without dilatation, gave the first idea of opening the mouths of the wounds. But from experience they altered this practice in part, and became not so desirous of searching after these extraneous bodies; for they found that it was oftener impossible to find them than could at first have been imagined, and when found, that it was not possible to extract them, and that afterwards these bodies were brought to the skin by the parts themselves, and those that could not be brought to the external surface in this way were such as gave little or no trouble afterwards, such as balls. Yet they altered this practice only so far as respected the attempt to'extract extraneous bodies; for when they found from experience that it was not necessary nor possible 516 HUNTER ON THE BLOOD. to extract these immediately, yet they did not see that it therefore was not necessary to take the previous or leading steps towards it. The circumstances I have mentioned of gunshot wounds being contused obliges most of them to suppurate, because in such cases there is more or less of a slough to be thrown off, especially at the orifice made by the entrance of the ball: there is therefore a freer passage for the matter, or any other extraneous substance, than the same-sized wound would have if made by a clean cutting instrument, even if not allowed to heal by the first intention. From all which, if there is no peculiarity in a gunshot wound, I think this of dilating them, as a general practice, should be rejected at once; even if it were only for this reason, that few gunshot wounds are alike, and therefore the same practice cannot apply to all. This treatment of gunshot wounds is diametrically opposite to a principle which is generally adopted in other cases, although not understood as a general rule, which is, that very few wounds of any kind require surgical treatment at their commencement, excepting with an opposite view from the above, viz., to heal them by the first intention. It is contrary to all the rules of surgery founded on our knowfedge of the animal ceconomy to enlarge wounds simply as wounds. No wound, let it be ever so small, should be made larger) excepting when preparatory to something else, which will imply a complicated wound, and which is to be treated accordingly; it should not be opened because it is a wound, but because there is something necessary to be done which cannot be executed unless the wound is enlarged. This is common surgery, and ought also to be military surgery respecting gunshot wounds. As a proof of the inutility of opening gunshot wounds as a general practice, I shall mention the cases of four Frenchmen and a British soldier, wounded on the day of the landing of our army on the island of Belleisle; and as this neglect rather arose from accident than design, there is no merit claimed from the mode of treatment, A. B. was wounded in the thigh by two balls; one went quite through, the other lodged somewhere in the thigh, and was not found while he was under our care. B. C. was shot through the chest; he spit blood for some little time. C. D. was shot through the joint ofthe knee; the ball entered at the outer edge of the patella, crossed the joint under that bone, and came out through the inner condyle ofthe os femoris. D. E. was shot in the arm : the ball entered at the inside of the insertion of the deltoid muscle, passed towards the head of the os humeris, then between the scapula and ribs, and lodged between the basis of the scapula and spinal processes, and was afterwards extracted. The man's arm was extended horizontally when the ball entered, which accounts for this direction. These four men had not anything done to their wounds for four days after receiving them, as they had hid themselves in a farm-house OF THE TREATMENT OF GUNSHOT WOUNDS. 517 all that time after we had taken possession of the island ; and when they were brought to the hospital their wounds were only dressed superficially, and they all got well. A grenadier ofthe 30th regiment was shot through the arm ; the ball seemed to pass between the biceps muscle and the bone; he was taken prisoner by the French. The arm swelled considerably, they fomented it freely, and a superficial dressing only was applied. About a fortnight after the accident he made his escape, and came to our hospital; but by that time the swelling had quite subsided, and the wounds healed: there only remained a stiffness in the joint of the elbow, which went off by moving it.

§ 1. Of the propriety of dilating Gunshot Wounds. It would be absurd for any one to suppose that there is never occasion to dilate gunshot wounds at all; but it is certain there are very few in which it is necessary.* It will be impossible to determine by any general description what those are that ought to be opened, and what those are that ought not; that must be left in a great measure to the discretion of the surgeon, when once he is master of the arguments on both sides. Some general rules may be given with regard to the more simple cases; but with regard to the more complicated, the particular circumstances of each case are the only guide; and they must be treated according to the general principles of surgery. Let us first give an idea of the wound that would appear to receive no benefit from being dilated: and first of the most simple wounds. If a ball passes through a fleshy part where it can hurt no bone in its way, such as the thick of the thigh, I own, in such a simple wound, I see no reason for opening it; because I see no purpose that can be answered by it, except the shortening of the depth of the wound made by the ball, which can be productive of no benefit. If the ball does not pass through, and is not to be found, opening can be of as little service. . If the opening in the skin should be objected to as being too small and thereby forming an obstruction to the exit of the slough, etc., I think that in general it is not: for the skin is kept open by its own elasticity, as we see in all wounds; this elasticity muscles and many other parts have not; and in general the opening made by a ball is much larger than those made by pointed instruments; for I already observed that there is often a piece of the skin carried in before the ball, * Pare TThp practice of dilating gunshot wounds was forcibly inculcated by Ambrose -are and Wiseman, and afterwards, in 1792, by Baron Percy whom his Manuel deChirurzien d'Armee, says, "The first indication of cure is to change the nature of nre wound as nearly as possible into an incised one." The judicious restriction of fhis practi e Jsuchcases as are pointed out in the concluding part of this fully borne out by the experience of our army surgeons during the section was late war.] . ., 44 518 HUNTER ON THE BLOOD. especially if it passed with considerable velocity, beside the circular slough; so that there is really in such cases a greater loss of substance ; therefore whatever matter or extraneous body there is, when it comes to the skin it will find a free passage out. Nor does the wound in the skin in general heal sooner than the bottom; and indeed in many cases not so soon, because the skin is generally the part that has suffered most. However, this is not an absolute rule, for the skin sometimes heals first; but I have found this to be the case as often where openings had been made as in those where they had not; and this will depend upon circumstances or peculiarities; such as the bottom being at a considerable distance, with extraneous bodies, and having no disposition to heal, tending to a fistula; and I have observed in those cases, that the wound or opening made by the surgeon generally skinned to a small hole before the bottom ofthe wound was closed, which brings it to the state it would have been in if it had not been dilated at all, especially if there are extraneous bodies still remaining ; for an extraneous body causes and keeps up the secretion of matter, or rather keeps up the disease at the bottom of the wound, by which means the healing disposition of its mouth is in some degree destroyed. Let me state a case of this last description. Suppose a wound made with a ball; that wound (from circumstances) is not to heal in six months, because the extraneous bodies, etc., cannot be extracted, or work out sooner, or some other circumstance prevents a cure in a shorter time: open that wound as freely as may be thought necessary, I will engage that it will be in a month's time in the same state with a similar wound that has not been opened, so that the whole advantage (if there is any) must be before it comes to this state; but it is very seldom that anything of consequence can be done in that time, because the extraneous bodies do not come out at first so readily as they do at last, for the inflammation and tumefaction, which extend beyond that very opening, generally keep them in ; and if the wound is opened on their account at first, it ought to be continued to the very last. Upon the same principle, opening on account of extraneous bodies at first cannot be of so much service as opening some time after; for the suppuration, with its leading causes, viz., inflammation and sloughing, all along the passage of the ball, makes the passage itself much more determined and more easily followed; for the want of which few extraneous bodies are ever extracted at the beginning, excepting what are superficial, small, and loose. If the extraneous bodies are broken bones, it seldom happens that they are entirely detached, and therefore must loosen before they can come away; also the bones in many cases are rendered dead, either by the blow or by being exposed, and must exfoliate, and this requires some time; for in gunshot wounds, where bones are either bruised or broken, there is most commonly an exfoliation, because some part of the bone is deadened, similar to the slough in the soft parts. OF THE TREATMENT OF GUNSHOT WOUNDS. 519 A reason given for opening gunshot wounds is, that it takes off the tension arising from the inflammation and gives the part liberty; this would be very good practice if tension or inflammation were not a consequence of wounds; or it would be very good practice, if they could prove that the effects from dilating a part that was already wounded were very different, or quite the reverse of those ofthe first wound ; but as this [dilatation] must always be considered as an extension of the first mischief, we must suppose it to produce an increase of the effects arising from that mischief; therefore this practice is contradictory to common sense and common observation. They are principally the compound wounds that require surgical operations, and certain precautions are necessary with regard to them, which I shall here lay down. As the dilatation of gunshot wounds is a violence, it will be necessary to consider well what relief can be given to the parts or patient by such an operation ; and whether without it more mischief would ensue; it should also be considered what is the proper time for dilating. But it will be almost impossible to state what wound ought and what ought not to be opened ; this must always be determined by the surgeon, after he is acquainted with the true state of the case and the general principles ; but from what has been already said, we may in some measure judge what those wounds are that should be opened, in order to produce either immediate relief, or to assist in the cure; we must have some other views than those objected to; we must see plainly something to be done for the relief of the patient by this opening, which cannot be procured without it, and if not procured, that the part cannot heal, or that the patient most probably must lose his life. The practice to be recommended here will be exactly similar to the common practice of surgery, without paving any attention to the cause as a gunshot wound. One of the principal points of practice will be to determine at what period of time the dilatation should be made. 1. If the wound should be a slight one, and should require opening, it will be better to do it at the beginning before inflammation comes on; for the inflammation, in consequence of both, will be slight; but in slight cases dilatation will never ^ necessary, except to allow of the extraction of some extraneous body that is near. But if the wound is a considerable one, and it should appear upon consideration that you cannot relieve immediately .any paticular part or the constitution, then you can gain nothing by opening immediate y but will only increase the inflammation, and in some cTsestie\nflammationy arising from the accident and opening "gether may be too much for the patient: under t - a t c stance it would be more advisable to wait till the first ^m^ ceases bv which means the patient will stand a much better cnance of a cure7if not of his life ; therefore it is much better to divide the ot a cure, n iiul possible that the inflammation may '^ToTsome°dr—c! in the wound which could he rl arise 520 HUNTER ON THE BLOOD. moved by opening it; for instance, a ball or broken bone pressing upon some part, whose actions are either essential to the life of the part or the whole, as some large artery, nerve, or vital part; in such the case will determine for itself. On the other hand, it may in many cases be better to remove the whole by an operation, when in such parts as will admit of it, which will be taken notice of. 2. If an artery is wounded, where the patient is likely to become either too weak, or to lose his life from the loss of blood, then certainly the vessel is to be tied, and most probably this cannot be done without previously opening the external parts, and often freely. 3. In a wound of the head where there is reason to suspect a fracture of the skull, it is necessary to open the scalp, as in any other common injury done to the head where there was reason to suspect a fracture; and when opened, if a fracture is found, it is to be treated as any other fractured skull.* 4. Where there are fractured bones in any part of the body, which can be immediately extracted with advantage, and which would do much mischief if left, this becomes a compound fracture wherever it is, and it makes no difference in the treatment whether the wound in the skin was made by a ball or the bone itself, at least where the compound fracture is allowed to suppurate ; for there is often a possibility of treating a compound fracture as a simple one, which gunshot fractures, if I may be allowed the expression, seldom will allow of; but where the compound fracture must suppurate, there they are very similar. However, there have been instances where a fracture of the thigh-bone made by a ball has healed in the same way as a compound fracture by other means. 5. Where there is some extraneous body which can with very little trouble be extracted, and where the mischief by delay will probably be greater than that arising from the dilatation. 6. Where some internal part is misplaced, which can be replaced immediately in its former position, such as in wounds in the belly, where some ofthe viscera are protruded, and it becomes necessary to perform the operation of gastroraphia ; which is to be done in this case in the same manner as if the accident arose from any other cause; but the treatment should be different, for gunshot cases cannot heal by the first intention, on account of the slough that is to ensue. 7. When some vital part is pressed, so that its functions are lost or much impaired, such as will often happen from fractures of the skull, fractures of the ribs, sternum, etc., in short, when anything can be done to the part after the opening is made for the present relief of the patient, or the future good arising from it. If none of these circumstances has happened, then I think we should be very quiet. Balls that enter any of the larger cavities, such as the abdomen or thorax, need not have their wounds dilated, except some- * [See Principles of Surgery, p. 266, no/e.] OF THE TREATMENT OF GUNSHOT WOUNDS. 521 thing else is necessary to be done to the contained parts, for it is impossible to follow the ball; therefore they are commonly not opened, and yet we find them do very well. Balls that enter any part where they cannot be followed, such as into the bones of the face, need not have the wound in the skin in the least enlarged, as it can give no assistance to the other part of the wound, which is a bony canal. The following cases are strongly in proof of this, being respectively instances of both modes of practice. I was sent for to an officer who was wounded in the cheek by a ball, and who had all the symptoms of an injured brain; upon examining the parts, I found that the ball had passed directly backwards through the cheek-bone; therefore, from the symptoms and from the direction of the wound, I suspected that the ball had gone through the basis of the skull into the brain, or at least had produced a depression of the skull there. I enlarged the external wound, and with my fingers could feel the coronoid process of the lower jaw; I found that the ball had not entered the skull, but had struck against it about the temporal process of the sphenoid bone, which it had broke, and afterwards passed down on the inside of the lower jaw. With a pair of small forceps I extracted all I could of the loose pieces of bone: he soon recovered from his stupor, and also from his wound. The ball afterwards caused an inflammation at the angle of the lower jaw, and was extracted. The good which I proposed by opening and searching for extraneous bodies and loose pieces of bone was the relieving of the brain; but as the ball had not entered the skull, and as none of the bones had been driven into the brain, it is most probable that I did no good by my opening; but that I could not foresee. An officer received a wound by a ball in the cheek (which in this case was on the opposite side) ; the wound led backwards, as in the other ; by putting my finger into the wound I felt the coronoid process of the lower jaw, as in the former; but he had no symptoms of an injured brain; I therefore advised not to open it, because the reason for opening in the preceding case did not exist here; my advice was complied with, and the wound did well, and rather better than the former, by healing sooner. The ball was never found, so far as I know. , ., . . , The present practice is not to regard the balls themselves, and seldom or ever to dilate upon their account, nor even to search much after them when the wound is dilated, which shows that opening is not necessary, or at least not made upon account of extraneous bodies. This practice has arisen from experience ; for it was found that balls, when obliged to be left seldom or ever did any harm when at rest, and when not in a vital part; for balls have been known to lie in the body for years, and are often never found at all and yet the person has found no inconvenience. This knowledge'of the want of power in balls to promote inflammation when left in the body, arose from the difficulty of finding them, or extract- 522 HUNTER ON THE BLOOD. ing them when found, and therefore in many cases they were obliged to leave them. One reason for not readily finding the ball at first is, because the parts are only torn and divided, without any loss of substance (till the slough comes off), by which means the parts collapse and fall into their places again, which makes it difficult to pass anything in the direction of the ball, or even to know its direction. The different courses they take, by being turned aside by some resisting body, add also to the difficulty, as will be explained. But the course of a ball, if not perpendicular, but passing obliquely and not very deep a little way under the skin, probably an inch or more, is easy to be traced through its whole course, for the skin over the whole passage of the ball generally is marked by a reddish line. I have seen this redness, even when the ball has gone pretty deep: it has none of the appearances of inflammation, or of-extravasation, for extravasation is of a darker colour, and what it is owing to I have not been able to discover. I can conceive it to be something similar to a blush, only the small vessels allowing the red particles of the blood to flow more easily.

§ 2. Of the strange Course of some Balls. The difficulty of finding balls, I have just observed, often arises from the irregular course they take. The regularity of the passage of a ball will in general be in proportion to its velocity and want of resistance, for balls are turned aside in an inverse proportion to the force that they come with, and this is the reason why we seldom find them take a straight course; for if they are spent balls, the soft parts alone are capable of turning them; and if they come with a considerable velocity it is a chance they may hit some bone obliquely, and then they are also turned aside, for anybody .hat gives a ball the least oblique resistance throws it out of its direct course ; therefore the balls that do not pass through and through (which are the only ones that are searched after), will be in general spent ones, excepting those that come directly against some considerable bone, as the thigh-bone, etc. As a proof that balls are easily thrown off obliquely, we often find that a ball shall enter the skin of the breast obliquely, and afterwards shall pass almost round the whole body under the skin. The skin here is strong enough to stop the ball coming out again, so that it turns it inwards, which, meeting with the ribs, it is again turned out against the skin, and so on alternately as long as it has force to go on; however, in many cases the ball goes a little way after it has passed through the skin, and when it meets with any hard body on that side next the centre ofthe body, such as a rib, its course is directed outwards, and it pierces the skin a second time; but the velocity of such balls must have been considerable. I have seen a ball pass in at one side of the shin-bone, and run across it under the skin, without either cutting the skin across or OF THE TREATMENT OF GUNSHOT WOUNDS. 523 hurting the bone, which shows that the velocity could not be great: for we know that there is not sufficient room between these two parts in a natural slate for a ball to pass; but the ball, after it had got under the skin, where there was room for it to cover itself, then came against the tibia, which threw it outwards, and the skin counteracting, it only raised the skin from the tibia, and passed on between them; but if this ball had had a sufficient velocity it would have either cut the skin across, or taken a piece out of the bone, or most probably both. Another circumstance in favour of the uncertainty of their direction is, that the parts wounded are often not in the same position that they were when they received the ball. The French soldier who was wounded in the arm was a striking instance of this. The ball entered the arm about its middle on the inside ofthe biceps muscle, and it was extracted from between the two scapulas, close on one side of the spinal process of the back-bone. The reason of this strange course I have already observed in the case, was owing to his having had his arm stretched out horizontally at the time he was wounded, and the ball passed on in a straight line. These uncertainties in the direction ofthe balls above-mentioned have made the common bullet-forceps almost useless ; yet forceps are not to be entirely thrown aside, for it will often happen that a ball will be found to lie pretty near the external wound, which, if the ball was removed, would probably heal by the first intention ; for in such superficial wounds they must have passed with little velocity ; or if there was a part killed, it would heal immediately ; but if there is a slough, the extraction is best done after all inflammation, and the separation of the slough is over, for then the passage of the ball is better ascertained, in consequence of the surrounding adhesive inflammation; and moreover, the granulations are beginning to push the extraneous body towards the surface ; but the operation of ulceration, which brings it to the skin, being often too slow, the ball, etc., had better be extracted, and even the part might be dilated. However, I would be very cautious how far I carried this practice, and only do it when all circumstances favoured. For the same reasons probes are become of little use , indeed, I think that they should never be used but by way of satisfaction, m knowing sometimes what mischief is done; we can perhaps feel if a bone is touched, or if a ball is near, etc., but when all this is known it is a hundred to one if we can vary our practice in consequence of it. If the wound will admit of it, the finger is the best instrument. ,, , .. , • In cases where the ball passes a considerable way under the skin, and near to it, I think it would be advisable to make an opening midway between the two orifices which were made by the ball (especially when the orifices are at a very great distance), that Sed bones, or extraneous bodies may now or hereafter be better extracted ; for if this is not done we have often an abscess forming between them, which indeed answers the same purpose, 524 HUNTER ON THE BLOOD. and often better; but sometimes it should not be delayed for such an event to take place. Where the ball has passed immediately under the skin, as in the case where the ball passed between the skin and tibia, it will be often proper to open the whole length of the passage of the ball, the necessity of which I think arises from the skin not so readily uniting with the parts underneath, as muscles do with one another. Although we have given up in a great measure the practice of searching after a ball, broken bones, or any other extraneous bodies, yet it often happens that a ball shall pass on till it comes in contact with the skin of some other part, and where it can be readily felt; the question is, should such a ball be cut out ? If the skin is bruised by the ball coming against it, so that we may imagine that this part will slough off, in that case I see nothing to hinder opening it, because the part is dead ; therefore no more inflammation can arise from the opening than otherwise would take place upon allowing the slough to be thrown off; while, on the other hand, I should also suppose as little good to arise from it, because the ball will come out of itself when the part sloughs off; however, it maybe suspected that before the slough falls off the ball may so alter its situation that it will be impossible to extract it by that opening ; however, I should very much doubt the ball altering its course under such circumstances, for if the skin was so much bruised as to slough, inflammation would soon come on, and confine the ball to that place; however, it always gives comfort to the patient to have the ball extracted. But if the ball is only to be felt, and the skin quite sound, I would in that case advise letting alone, till the wound made by the entrance of the ball had inflamed and was suppurating; my reasons for it are these : First, we find that most wounds get well when the ball is left in, (excepting it has done other mischief than simply passing through the soft parls,) and that very little inflammation attends the wound where the ball lodges, only that where it enters ; the inflammation not arising so much from the injury done by the ball as from the parts being there exposed to the suppurative inflammation, if it is immediately removed. There is always a greater chance of a slough where the ball enters then where it rests, arising from the greater velocity of the ball; for beyond where the slough is the parts unite by the first intention. Secondly, in those cases where the ball passes through and through we have two inflammations, one at each orifice, instead of the one at the entrance; or a continuedimflammation through and through, if the ball has passed with great velocity. Where the ball makes its exit, the inflammation passes further along the passage of the ball than when the wound has been healed up to the ball, and then cut out afterwards; so that by opening immediately the irritation will be extended further, and of course the disposition for healing will be prevented. If this is the case, I think that two wounds should not be made OF THE TREATMENT OF GUNSHOT WOUNDS. 525 at the same time ; and what convinces me more of it is, that I have seen cases where the balls were not found at first, nor even till after the patients had got well of their wounds; and these balls were found very near the skin. They gave no trouble (or else they would have been found sooner); no inflammation came upon the parts, and they were afterwards extracted and did well. Again, I have seen cases where the balls were found at first and cut out immediately, which were similar to balls passing through and through ; and in these the same inflammation came on the cut wounds that came on the wounds made by the entrance of the ball.

§ 3. Penetrating Wounds ofthe Abdomen.

Wounds leading into the different cavities ofthe body are very common in the army, and in a great measure peculiar to war. They are mostly gunshot wounds, but not always, some being made with sharp-pointed weapons, as swords, bayonets, &c.; they are pretty similar, in whatever way they are made, and I have given them a name expressive of the nature of the wound. I shall not take notice of any of this kind but those which penetrate into the larger cavities, as the abdomen, thorax, and skull; but those into the skull are made most commonly by balls, shells, &c. These wounds become more or less dangerous according to the mischief done to the contents of the cavity into which they penetrate. These wounds may be distinguished according as they are simply penetrating, without extending to the contained parts, or as they affect these parts, and the event of these two kinds of wounds is very different; for in the first little danger is to be expected if properly treated, but in the second the success will be very uncertain, for very often nothing can be done for the patient under such wounds, and very often a good deal of art can be made use of with advantage. . Wounds of the parietes of the abdomen, not immediately indicted on such a viscus as has the power of containing other matter, will in general do well, let the instrument that made the wound be what it will.* There will be a great difference, however, should that instrument be a ball passing with great velocity, for in this case a slough will be produced ; but if it should pass with little velocity, then there will be less sloughing, and the parts will in some degree heal by the first intention, similar to those made by a cutting instrument. But although the ball has passed with such velocity as to produce a slough, yet that wound shall do well, for the adhere inflammation will tike place on the peritoneum all round t.he wo nd, which will exclude the general cavity from taking part in the ini .„:„;*»- victim is a viscus that contains some foreign

blood-vessels. ._ 45 526 HUNTER ON THE BLOOD. flammation, although the ball has not only penetrated but has wounded parts which are not immediately essential to life, such as the epiploon, mesentery, &c, and perhaps gone quite through the body; yet it is to be observed that wherever there is a wound, and whatever solid viscus may be penetrated, the surfaces in contact, surrounding every orifice, will unite by the adhesive inflammation, so as to exclude entirely the general cavity, by which means there is one continued canal wherever the ball or instrument has passed; or if any extraneous body should have been carried in, such as clothes, &c. they will also be included in these adhesions, and both these and the slough will be conducted to the external surface by either orifice. All wounds that enter the belly, which have injured some viscus, are to be treated according to the nature of the wounded part, with its complications, which will be many, because the belly contains more parts of very dissimilar uses than any other cavity in the body, each of which will produce symptoms peculiar to itself and the nature ofthe wound. The wounding of the several viscera will often produce what may be called immediate and secondary symptoms, which will be peculiar to themselves, besides what are common to simple wounds, such as bleeding, which is immediate, and inflammation and suppuration, which are secondary. Sensations alone will often lead to the viscus wounded, and this is frequently one of the first symptoms. The immediate symptoms arising from wounds in the different viscera are as follows : From a wound in the liver there will be pain in the part of the sickly or depressing kind ; and if it is in the right lobe, there will be a delusive pain in the right shoulder, or in the left shoulder from a wound in the left lobe. A wound in the stomach will produce great sickness and vomiting of blood, and sometimes a delirium ; a case of which I once saw in a soldier in Portugal, who was stabbed into the stomach with a stiletto by a Portuguese. Blood in the stools will arise from a wound in the intestines, and according to the intestine wounded it will be more or less pure. If the blood is from a high part of an intestine, it will be mixed with faeces and of a dark colour; if low, as the colon, the blood will be less mixed and give the tinge of blood ; and the pain or sensation will be more or less acute according to the intestine wounded: more of the sickly pain the higher the intestine, and more of the acute the lower. There will be bloody urine from a wound in the kidneys or bladder ; and if made by shot or ball, and a lodgement made, these bodies will sometimes become the cause of a stone. The sensation will be trifling. A wound of the spleen will produce no symptoms that I know of, excepting probably sickness, from its connection with the nerves belonging to the stomach, &c. OF THE TREATMENT OF GUNSHOT WOUNDS. 527 Extravasations of blood into the cavity of the abdomen will take place more or less in all penetrating wounds, and more especially if some viscus is wounded, as they are all extremely vascular; and this will prove dangerous or not, according to the quantity. These are the immediate and general symptoms upon such parts being wounded; but other symptoms may arise, in consequence of some of those viscera being wounded, which require particular attention. There may be wounds of the liver and spleen which produce no symptoms but what are immediate, and may soon take on the healing disposition; but wounds in those viscera which contain extraneous matter, such as the stomach, intestines, kidneys, ureters, and bladder, may produce secondary symptoms of a distinctive kind. If the injury is done by a ball to any of those viscera, the effect may be of two kinds: one where it makes a wound, as stated above, the other where it only produces death in a part of any of them ; these will produce very different effects. The first will most probably be always dangerous: the second will hardly ever be so. The first is where the ball has wounded some one of the above mentioned viscera in such a manner as not to produce the symptoms already described, but one common to them all, viz., their contents or extraneous matter immediately escaping into the cavity of the abdomen. Such cases will seldom or ever do well, as their effect will hinder the above-mentioned adhesions taking place ; the consequence of which will be that universal inflammation on the peritoneum will take place, attended with great pain, tension, and death. But all this will be in proportion to the quantity of wound in the part, and quantity of contents capable of escaping into the cavity of the abdomen; for if the wound is small, and the bowels notful, then adhesions may take place all round the wound, which will confine the contained matter, and make it go on in its right channel. These adhesions may take place very early, as the following case shows. , . . . , . , The case of an officer who died of a wound which he received

^ Thursday morning, the 4th of September, 1783 about seven o'clock, an officer fought a duel in the Ring in Hyjie^ark, in which he exchanged three shots with his antagonist whose last shot struck him on the right side, just belov,Mhe la..t nb, and appeared under the skin on the opposite side,^tlv m the corresponding place, and was immediately cut out by Mr.

^About three hours after receiving this wound, 1[sawhim with Mr Grant. He was pretty quiet, not much pain, rather low, pulse

fot q^k 'nor full aa J •^^^0^07' StnTeS me suspect something imore than a °™™™rore k could not be

ne^Y-%ZJZZtoM His belly had been fomented, ti^d^^*™ ordered and a araught with confec. cardUs a cordial, with twenty drops of laudanum, to procure sleep, 528 HUNTER ON THE BLOOD. as he wished to have some. We saw him again at three o'clock : the draught had come up. Had no stool from the clyster, nor any sleep; had made water, and no blood being found in it, we conjectured that the kidneys, &c, were not hurt. He was now rather lower, pulse smaller, more restless, a good deal of tension in the belly, which made him uneasy, and made him wish to have a stool. It was at first imagined that this tension might be owing to extravasated blood; but on patting the belly, especially along the course of the transverse arch of the colon, it plainly gave the sound and vibration of air; therefore we wished to procure a motion, to see if we could not by that means have some of that air expelled. We wished also to repeat the cordial and the opium, but the stomach was become now too irritable to retain anything, and was at times vomiting, independently of anything he took : a clyster was given, but nothing returned or came away. We saw him again at nine o'clock in the evening. His pulse was now low and more frequent, coldness at times, vomiting very frequent, which appeared to be chiefly bile, with small bits of something that was of some consistence; the belly very tense, which made him extremely uneasy; no stool. From nothing passing downwards, and the colon continuing to fill, we began to suspect that it was becoming paralytic, probably from the ball having divided some of its nerves. Fumes of tobacco by clyster were proposed, but we were loath to use it too hastily, as it would tend to increase the disease, if it did not relieve; however, we were prepared for it. Mr. Grant stayed with him the whole night; all the above symptoms continued increasing, and about seven o'clock in the morning he died, viz., about twenty-four hours after receiving the wound. He was opened next day at ten o'clock, twenty-seven hours after death, when we found the body considerably putrid, although the weather was cold for the season, the blood having transuded all over the face, neck, shoulders and breast, with a bloody fluid coming out of his mouth, with an offensive smell: below this the body was not so far gone. On opening the abdomen a good deal of putrid air rushed out; then we observed a good deal of fluid blood, principally on each side ofthe abdomen, with some coagulum upon the intestines ; when sponged up it might be about a quart. The small intestines were slightly inflamed in many places, and there adhered. We immediately searched for the passage of the ball. On searching for the course of the ball we found that it had passed directly in, pierced the peritoneum, entered again the peritoneum where it attaches the colon to the loins, passed behind the ascending colon, and just appeared at the right side of the root of the mesentery .where the colon is attached; passed behind the root ofthe mesentery, and entered the lower turn ofthe duodenum as it crosses the spine: then passed out of that gut on the left of the mesentery, and in its course to the left side it went through the OF THE TREATMENT OF GUNSHOT WOUNDS. 529 jejunum, about a foot from its beginning; then through between two folds of the lower part of the jejunum, taking a piece out of each; then passed before the descending part of the colon, and pierced the peritoneum of the left side, as also some ofthe muscles, but not the skin, and was immediately cut out exactly in the same place on the left where it entered at the right; so it must have passed perfectly in a horizontal direction. There was no appearance of extravasation of any of the contents of the intestines loose in the cavity of the abdomen, The intestines in many places were adhering to one another, especially near to the wounds, which adhesions were recent, and of course very slight; yet they showed a ready disposition for union to prevent the secondary symptoms or what may be called the consequent, which would also have proved fatal. There was little or no fluid in the small intestines, but there was a good deal of substance in consistence like fasces, in broken pieces about the size of a nut, through the whole track of the intestines, even in the stomach, which he vomited up; but in the upper end of the jejunum, as also in the duodenum, there was some fluid mixed with the other; but that fluid seemed to be rather bile. If this solid part was excrement, then the valve ofthe colon must not have done its duty. Was all the thin part absorbed to hinder extravasation into the belly? or was it all brought back into the stomach to be vomited up? There was a good deal of air in the ascending, but more especially in the transverse turn ofthe colon. This case admits of several observations and queries. First, the lowness and gradual sinking, with the vomiting without blood, bespoke wounded intestines, and those pretty high up. It shows how ready Nature is to secure all unnatural passages, according to the necessity. Query, what could be the cause of his having no stool, even from the clyster? Were the intestines inclinable to be quiet under such circumstances ? Would he not have lived if the immediate mischief had not been too much ? I think that if the immediate cause of death had not been so violent, Nature would have secured the parts from the secondary, viz., the extravasation of the fasces. What is the best practice where it is supposed an intestine may be wounded ? I should suppose the very best practice would be to be quiet and do nothing, except bleeding, which in cases of wounded intestines is seldom necessary. As he was extremely thirsty, and could not retain anything in his stomach, which, if he could, would probably have been productive of mischief, by giving a greater chance of extravasation: would not the tepid bath have been of service, to have allowed of fluids to enter the constitution ? . , It is very possible that a wound of the gall-bladder, but more readilv of the ductus communis, and also of the pancreatic duct, will produce the same effects, although not so quickly; and it may be observed, that a wound in them could not be benefited by any 45* 530 HUNTER ON THE BLOOD. adhesions that could take place, because the secreted fluids could never, most probably, get into the right channel again, and would therefore be the cause of keeping the external wound open to discharge the contents, as we find to be the case in the disease called fistula lachrymalis, as also when the duct of the parotid gland is divided. Wounds of parts that have been only deadened will be very similar to the above-stated penetrating wounds, but they will differ from them in effects, arising from a slough separating from a containing viscus; for whenever the slough comes away the extraneous or contained matter of that viscus will escape by the wound, such as the contents of the stomach, intestines, ureters, bladder, etc., the two last of which will be similar; or the slough may escape by either of these outlets; whereas in the former kind of wounds any of the contents that could possibly escape would immediately pass into the cavity of the abdomen. The periods of these symptoms appearing after the accident will be according to the time of separation, which may be in eight, ten, twelve, or fourteen days. These new symptoms, although in general very disagreeable, will not be dangerous,* for all the danger is over before they can appear; but that the orifice should afterwards continue, and become either an artificial anus or urethra, is a thing to be avoided ; though they commonly close up, and the contents are directed the right way : in such cases nothing is to be done but dressing the wound superficially, and when the contents ofthe wounded viscus become less, we may hope for a cure. The following case explains the foregoing remarks : A young gentleman was shot through the body. The musket was loaded with three balls, but there were only two orifices where they entered, and also only two where they came out, one of the balls having followed one of the others; that there were three that went through him was evident, for they afterwards made three holes in the wainscot behind him, but two very near one another.f The balls entered upon the left side of the navel, one a little further out than the other, and they came out behind, pretty near the spinal processes, about the superior vertebras of the loins. From the closeness ofthe gun to the man when fired, which of course made its contents pass with great velocity, as also from the direction of the innermost ball, which we supposed to be the double one, we were pretty certain that it had penetrated the cavity of the abdomen, but could not be so certain of the course of the other. The first water he made after the accident was bloody, from which we knew the kidney was wounded ; but that symptom soon left him. He had no blood in his stools, from which we concluded that none of the intestines were wounded; and no symptoms of ex-

* How far the contents of the stomach escaping through a wound might not be attended with bad consequences I cannot pretend to say. f [Balls impinging on a sharp edge of bone have sometimes been known to be cut in two, and to take different courses in the body.] OF THE TREATMENT OF GUNSHOT WOUNDS. 531 travasation of the contents of any viscus taking place, such as the symptoms of inflammation of the peritoneum, we were still more confirmed in our opinion. The symptomatic fever did not run higher than could have been expected, nor was there more pain in the track ofthe ball than might be imagined. These consequent symptoms of the immediate injury abated as soon as could be expected, and in less than a fortnight I pronounced him out of danger from the wound; for no immediate secondary symptoms having taken place, I concluded that whatever cavities the balls had entered, there the surrounding parts had adhered, so that the passage of the ball was by this means become a complete canal; and therefore, that neither any extraneous bodies that had been carried in with the balls, and had not been carried through, nor any slough that might separate from the sides ofthe canal, nor the matter formed in it, could now get into the cavity ofthe abdomen, but must be conducted to the external surface of the body, either throuo-h the wounds, or from an abscess forming for itself, which would work its own exit somewhere. But this conclusion was supposed to be too hasty, and soon after a new symptom arose, which alarmed those who did not see the propriety of my reasoning ; which was some fasces coming through the wound: this new symptom did not alter my opinion respecting the whole operations of Nature to secure the cavity of the abdomen, but it confirmed it (if a further confirmation had been necessary), and therefore I conceived it could not affect life; but as 1 saw the possibility of this wound becoming an artificial anus, 1 was sorry for it. It was not difficult to account for the cause of this new symptom; it was plain that an intestine (the descending part ofthe colon most probably), had only received a bruise from the ball, but sufficient to kill it at this part, and til the separation of the slough had taken place, both the intestine and canal were still complete, and therefore did not communicate with each other but when the slough was thrown off, the two were laid into one at this part, therefore^ contents ofthe intestine got into the wound and the matter from the wound might have got into the intestine. However this symptom gradually decreased, by (we may suppose) the Sal compaction of this opening, and an entire stop to the course of the fasces took place, and the wounds healed very kindly up. But the inflammation, the sympathetic fever the reducing treatment, and the spare regimen all tended to weaken him very much.

§ 4 Of penetrating Wounds in the Chest. Litlle notice has been taken of — Uthe eta, an^,u„gs;

in*1? L^" ^fa"«£S deal may be done for°.he good of the yet in many cases a great deal may

E1'3S SeConXr ccnp.ica.ed, vijawouud ofthe lung, 532 HUNTER ON THE BLOOD. It is pretty well known that wounds of the lungs (abstracted from other mischief), are not mortal. I have seen several cases where the patient has got well after being shot quite through the body and lungs, while from a very small wound made by a sword or bayonet into the lungs the patients have died, from which I should readily suppose that a wound in the lungs from a ball would in general do better than a wound in the same part with a pointed instrument; and this difference in effect would appear in many cases to arise from the difference in the quantity of blood extravasated, because the bleeding from a ball is very inconsiderable in comparison to that from a cut, and there is therefore a less chance of extravasated blood, either into the cavity of the thorax or into the cells of the lungs: another circumstance that favours gunshot wounds in these parts is, that they seldom heal up externally by the first intention, on account of the slough, especially at the wound made by the entrance of the ball, so that the external wound remains open for a considerable time, by which means any extravasated matter may escape; but even this has often its disadvantages, for by keeping open the external wound, which leads into the cavity, we give a chance to produce the suppurative inflammation through the whole surface of that cavity, which most probably would prove fatal, and which would be equally so if no viscus was wounded; but it would appear that the cavity of the thorax does not so readily fall into this inflammation from a gunshot wound as we should at first imagine ; nor can we suppose that the adhesive inflammation readily takes place between the lungs and pleura round the orifice, as we described in the wounds of the abdomen, because these parts arenot under the same circumstances that other contained and containing parts are; for in every other case the contained and containing have the same degree of flexibility or proportion in size. The brain and the skull have not the same flexibility, but they bear the same proportion in size. The lungs immediately collapse when either wounded themselves or when a wound is made into the chest, and, from this circumstance, are not allowed to heal up by the first intention, but become by much too small for the cavity of the thorax, which space must be filled either with air or blood, or both, so that adhesion cannot readily take place: but it very often happens that the lungs have previously adhered, which will frequently be an advantage. In the cases of slabs, especially if with a sharp instrument, the vessels will bleed freely, but the external wound will collapse, and cut off all external communication. If the lungs are wounded in the same manner, we must expect a considerable bleeding from them, and this bleeding will be into the general cavity of the thorax (if the lungs at this part have not previously adhered there), and likewise into the cells of the lungs or bronchias, which will be known by producing a cough, and in consequence of it a bleeding at the mouth; for the blood that is extravasated into the air-cells of the lungs will be coughed up by the trachea, and by that means will become a certain symptom of the lungs being wounded ; but OF THE TREATMENT OF GUNSHOT WOUNDS. 533 that which gets into the cavity of the thorax cannot escape, and therefore must remain till the absorbents take it up; which they will do if it is only in small quantity; but if in large quantity this extravasated blood will produce symptoms of another kind. The symptoms of these accidents are: first, a great lowness, which proceeds from the nature ofthe parts wounded, and perhaps a fainting from the quantity of blood lost to the circulation ; but this will be in proportion to the quantity and quickness with which it was lost. . A load in the breast will be felt, but more from a sensation of this kind than from any real weight; and a considerable difficulty in breathing. This difficulty in breathing will arise from the pain the patient will have in expanding the lungs in inspiration, and will also proceed from the muscles of respiration of that side being wounded, and this will continue for some time from the succeeding inflammation : it will hinder the expansion of the thorax on that side, and of course in some degree of the other side, as we have not the power of raising one side without raising the other ;* and if wounded by a cutting instrument, the lungs of that side not being able to expand fully, by the cavity of the thorax being in part filled with blood, will also give the symptoms of difficulty of breathing. The patient will not be able to lie down, but must sit upright, that the position may allow of the descent of the dia^ phragm, to give room in the chest: all which symptoms were strongly marked in the following case. A person received a stab behind the left breast with a small sword ; the wound in the skin was very small. He was almost immediately seized with a considerable discharge of blood from the lungs to near a quart, by the mouth, which showed that the lungs were considerably wounded, for from the situation of the external wound we were sure that the stomach could not be injured. His breathing soon became difficult and painful, and his pulse quick; he was bled; these symptoms increased so fast that every one thought him dying. He could only lie on his back ; for if he lay on trie sound side, he could not breathe in the least, and the pain would not let him lie on the unsound side; the easiest position was an erect posture, which obliged him to sit in a chair for several days; when he coughed he was in great pain; he very seldom spat with the cough, and never discharged any blood after the second day, by which we supposed that the bleeding was stopped

10 Whitefhe parts were in a state of inflammation he was in great pain, his breathing excessively quick, and his pulse hard and extremely quick ; but as the inflammation went off, he drew his breath !nlonger strokes, his pain became less, and his pukse not so quick nor so hard; but this last circumstance varied as he moved

, ,t -t _ „.reat pity that we do not accustom ourselves to J£ tZTotTX™ uCUuy of ,he other, as we from habit mo,o one eyelid independently ofthe other. 534 HUNTER ON THE BLOOD. his body, coughed, or put himself into a passion, which he often did. I suspected from both the wound and its effects that there was a good deal of extravasated blood in the cavity of the thorax; for I considered that the blood which got out of the vessels of the lungs into the wound in the lungs would find a readier passage into the cavity of the thorax than into the cells of the lungs; and indeed every attempt to dilate the thorax would rather act as a sucker upon the mouth of the wound in the lungs, as the pressure of the external air was taken off by that means: I proposed the operation of the empyema, because the extravasated blood must compress the lungs of that side, and hinder their expansion, and likewise irritate, and at last might produce inflammation. He continued for some days with little variation, but upon the whole seemed getting better; but the day before he died, he became worse in his breathing, which we imputed to his stirring too much, and was rather better on the day that he did die: just before death he was taken with a sort of suffocation, and in half an hour he died. Through his whole illness he had a moist skin, and sometimes sweated profusely; at last his legs swelled. At first he only took a spermaceti mixture with a little opium, which gave him relief; I wanted to increase the opium, but it was objected to, for fear it should bind the chest too much, as it often does in asthmas, therefore it was given with the squills. On the day that he died, we ordered him the bark with a sudorific. As this was very different from a common asthma, and the difficulty of breathing arose entirely from the inflammation of the intercostal muscles and lungs, and likewise from having but one lung, I thought it advisable to give opium in this case, as it would take off the irritation of the inflamed parts, and therefore allow a greater stretch or expansion ; especially as we found whenever it was given that it gave relief and produced these eflects. One might at first wonder why he should breathe with such difficulty, as be had one side whole or sound; for I have seen people breathe pretty freely who have had but one side to expand; but when we consider the case, we can easily account for this. After death we opened him. On reaching the sternum I cut into the cavity of the thorax, and a great deal of blood gushed out at the incision ; we sponged out of the left side of the thorax above three quarts of fluid blood ; the coagulum appeared to have been attracted to the sides of the cavity everywhere, as if it had been furred over with the coagulating lymph, which was nowhere floating in the fluid ; but most probably the extravasated blood had never coagulated, and this thick buffy crust was an exudation of coagulating lymph from the lungs and pleura, which covers the ribs as in all inflammations; if so, this is another instance, beside that ofthe inflammation ofthe veins, in which the coagulating lymph coagulates immediately upon being thrown upon the surface; for if it had not, it then must have mixed with the blood in the chest, and only OF THE TREATMENT OF GUNSHOT WOUNDS. 535 been found floating there. The lungs was collapsed into a very small substance,and was therefore firmer than common; we observed the wound in it, which corresponded to the wound in the pleura; I introduced a probe into the wound in the lung, which passed near four inches, but was not certain whether it did not make some way for itself; however, I traced the wound by opening the lung, and could easily distinguish the wounded part by the coagulated blood that lay in it. I found the heart and inside of the pericardium inflamed, and their surfaces furred over with coagulating lymph, similar to that on the lung. The lung of the right side had also become a little inflamed on its anterior edges. Wounds in the lungs generally become a cause of a quick pulse ; this likewise may arise in some degree from the lungs being so immediately concerned in the circulation, that anything that gives a check to the blood's free motion through them may affect the heart. But the pulse becomes hard, which arises from the nature of the inflammation that attends, and also from the wound being in a vital

^In the cases arising from balls, nothing in general is to be done but to keep quiet, and dress the wounds superficially; for any extravasated blood that might have got into the cavity of the thorax will generally make its escape by the external wound, as also any matter from suppuration. But in the cases of wounds made by cutting instruments, and where there is reason to suspect a considerable quantity of blood in the cavity of the thorax then we may ask what should be done; and the natural answer is, that the operation for the empyema should be performed This operation will relieve the patient and bring the disease to the [state of a] simple wound, and somewhat nearer to the gunshot wound; it should be performed as soon as possible, before the blood can have time to coagulate; for the coagulum of blood may be with difficulty extracted The enlargement of the wound already made will often answer' but if that is in such a situation as to forbid dilatation, then the common directions for the empyema are to be followed here. WheTal symptoms appear, and we have great reason to suppose a considemble extravasation of blood into the cavity of he chest I ffiink^that we should not hesitate in performing the operation for the empyema.

$ 5 Of Concussions and Fractures of the Skull.

These injuries, ^.f^^^^^^i [^t-TonhS S tagineU rehire no pecuhar

4 6 Of Wounds compounded uith Fractured Bones, or containing $ o- uj rroun i Extraneous Bodies. i u*t wounds, where bones are broken, or 536 HUNTER ON THE BLOOD. to compound fractures, seldom if ever heal at once, or by regular degrees, as wounds of the former kind, but generally heal very quick at first, upon the going off of the inflammation, similar to the healing of simple gunshot wounds; but when healed so far as to be affected by the extraneous bodies, then they become slow in their progress, till at last they come to a stand, or become fistulous; in which state they continue till the irritating cause is removed: and this takes place even if the dilatation should have been made at first as large as could be thought necessary; so that the opening at first, in such cases, can only let out those extraneous bodies or detached bones that are perfectly loose, or become loose while the wound continues large: however, even this can only take place in superficial wounds; but in those that are deep, or where there is an exfoliation to take place, the dilated part always heals up long before they are fit to make their exit; but before this happens the parts often acquire an indolent diseased state, and even when all extraneous bodies are extracted the parts do not readily heal. When a wound comes to this stage, surgeons generally put in sponge or other tents into the opening, or apply some corroding medicine to keep it open, and also with a view to make it wider; but this practice is unnecessary, as a wound in such a state seldom heals entirely over, nor do tents add much to the width of the wound, and always confine the matter [for the time] between the two dressings. Where an exfoliation is expected, it is generally better to expose as much ofthe bone as possible : it keeps up a kind of inflammation, which I imagine gives a disposition for this process. This can only be done where the bone is pretty superficial ; but in cases where the separation has already taken place, and it is now to make its way to the skin, like any other extraneous substance, then, instead ofthe practice of sponge tents to keep the orifice in the skin open, it would be often better in such cases to let the whole heal over; because the extraneous body would form an abscess round itself, which would enlarge the cavity, and produce the ulcerative inflammation quicker towards the surface ; and when that was opened, the extraneous body could be with more ease extracted, or would come out of itself: but this method of healing the mouths of fistulous sores is not always practicable. If this last practice has no inconveniences attending it, it has this advantage, that the patient has not the disagreeable trouble of having a sore to dress every day till the extraneous body comes away, which I think is no small consideration. This practice, however, is not to be followed in every case: for instance, if the wound should communicate with a joint as is common to most sores in the foot and hand where the bones are diseased, it would be in such cases very imprudent to allow the wound to heal, as the confined matter would get more readily into the different joints, and increase the disease: there may be other causes to forbid this as a general practice-. OF THE TREATMENT OF GUNSHOT WOUNDS. 537 If wounds are to be kept open at their mouths, whose bottoms have not a disposition to heal, they should be kept open to that bottom ; because, whenever they do heal at their mouths, it is most commonly owing to their sides underneath first uniting; for the skin will seldom unite when all beyond it is open. In wounds that become fistulous, where there is no extraneous body, there is always a diseased bottom, which is to be looked upon as having the same effect as an extraneous substance. To alter this diseased disposition they should be opened freely, as large openings produce quick inflammation, quick suppuration, and quick granulations, which are generally sound when they arise from such a cause: on the other hand, letting such wounds heal at their mouths has often a salutary effect, as it becomes a means of destroying this diseased part by the formation of an abscess there, and in general there can be no better way of coming at a part or extraneous body than by the formation of an abscess there. It is a natural way of opening to relieve diseased parts; but we often find in practice that this method is not sufficient, either for the extraction of extraneous bodies, or to expose the diseased bottom, excepting these abscesses are opened very largely by art, so as to expose the whole of the diseased parts or extraneous body.

§7. Ofthe Time proper for removing Incurable Parts.

Many gunshot wounds are at the very first evidently incurable, whether in a part that cannot be removed, or in one that will admit of being removed. When such wounds are in parts that will not admit of a removal of the parts injured, then nothing can be done by surgery; but when in a part that can be removed, then a removal of the injured part is to be put in practice; but even this is to be under certain restrictions: perhaps it should not be done immediately upon the receiving of the injury, excepting where a considerable blood-vessel is wounded, so as to endanger the life of he person, and that it absolutely cannot be taken up, or it is suspected that the inflammation in consequence of the accident will kill, by which means you have only the inflammation m consequence of the amputation; but this is a bad resource, especially if it is at lower^extremity that is to be amputated, and which is perhaps the only part that can be removed of which the inflammation will kill. How far the same practice is to be followed in.caseswhich we mav suppose will not kill, but that the part is so hurt as to all appeayrancPeP not to be in the power of surgery to save, I wi 1^ot now determine. This is a very different case ^m/he former a^nd it consequences depend more upon con^gen^s athsnt in other^e should be removed only when the state of the patient in other ienects willaTmit of it; but this is seldom the case, for few people nfu hea thTre in that state, and still less so those who are usually hesubiect; of gunshot wounds: the situation they are in at he fme from he ifurry of mind, makes it here in general to be the 538 HUNTER ON THE BLOOD. very worst practice; it will in general, therefore, be much better to wait till the inflammation, and all the effects of both the irritation and inflammation, shall be gone off. If these things are not sufficiently attended to, and the first inflammation, as in the first-stated case, (for instance, that which is likely to prove mortal,) is allowed to go on, the patient will most probably lose his life; or if the first inflammation is such as is likely to go off, according to the last-stated case, then we should allow it to go off before we operate, and not run the risk of producing death by an operation ; for I have already observed, few can support the consequences of the loss of a lower extremity when in full health and vigour. We know that a violent inflammation will in a few hours alter the healthy disposition, and give a turn to the constitution, especially if a considerable quantity of blood has been lost, which most probably will be the case where both accident and operation immediately succeed one another. The patient under such circumstances becomes low, simply by the animal life losing its powers, and hardly ever recovers afterwards. After considering the curative treatment of gunshot wounds and other accidents common to the soldier as also to the sailor, let us further consider the treatment of those patients whose wounds at the very first appear to be incurable when they are in parts that will admit of being removed. The operation itself is the same as in other cases, and the only subjects of peculiar consideration here are the situation of the patient, and the proper time for performing the operation after the injury. I have already given some directions with regard to the proper time of operating, in treating upon the dilatation of gunshot wounds, which are in some degree applicable here; but we shall consider this now more fully, as the proper time of removing a part is often much shorter than that of dilating. Amputation of an extremity is almost the only operation that can and is performed immediately on receiving the injury. As these injuries in the soldier are generally received at a distance from all care, excepting what may be called chirurgical, it is proper we should consider how far the one should be practised without the other. In general, surgeons have not endeavoured to delay it till the patient has been housed, and put in the way of a cure; and therefore it has been the common practice to amputate on the field of battle. Nothing can be more improper than this practice, for the following reasons ; in such a situation it is almost impossible for a surgeon, in many instances, to make himself sufficiently master of the case, so as to perform so capital an operation with propriety ; and it admits of dispute, whether at any time and in any place amputation should be performed before the first inflammation is over. When a case is so violent as not to admit of a cure in any situation, it is a chance if the patient will be able to bear the consequent inflammation; therefore in such a case it might appear, at first OF THE TREATMENT OF GUNSHOT WOUNDS. 539 sight, that the best practice would be to amputate at the very first; but if the patient is not able to support the inflammation arising from the accident, it is more than probable he would not be able to support the amputation and its consequences. On the other hand, if the case js such as will admit of being brought through the first inflammation, although not curable, we should certainly allow of it; for we may be assured that the patient will be better able to bear the second. If the chances are so even where common circumstances in life favour the amputation, how must it be where they do not? how must it be with a man whose mind is in the height of agitation, arising from fatigue, fear, distress, &c. 1 These circumstances must add greatlylo the consequent mischief, and cast the balance much in favour of forbearance. If it should be said that, agreeable to my argument, the same circumstances of agitation will render the accident itself more dangerous, I answer, that the amputation is a violence superadded to the injury, therefore heightens the danger; and when the injury alone proves fatal, it is by slower means. In the first case it is only inflammation; in the second it is inflammation, loss of substance, and most probably loss of more blood; as it is to be supposed that a good deal has been lost from the accident, not to mention the awkward manner in which it must be done. The only thing that can be said in favour of amputation on the field of battle is, that the patient may be moved with more ease without a limb than with a shattered one: however, experience is the best guide, and I believe it is universally allowed by those whom we are to esteem the best judges, those who have had opportunity of making comparative observations on men who have been wounded in the same battle, some where amputation had been performed immediately, and others where it had been left till all circumstances favoured the operation; it has been found, I say, that few did well who had their limbs cut off on the field of battle; while a much greater proportion have done well, in similar cases, who were allowed to go on till the first inflammation was over, and underwent amputation afterwards. . There will be exceptions to the above observations, which must be in a great measure left to the discretion of the surgeon; but a few of these exceptions may be mentioned, so as to give a general idea of what is meant. . . , .c First, k is of less consequence, whichsoever way it is treated, if the par to be amputated is an upper extremity ; but it may be obeyed that therewill be little occasion in general to amputate an wwr extremity upon the field, because there will be less danger "amoving suifiInpatient than if the injury had happened to the

10 Secondly, if the parts are very much torn, so that the limb only haws by a small connection, then the circumstance of the loss of so much substance to the constitution cannot be an objection, as it takes 540 HUNTER ON THE BLOOD. place from the accident, and indeed everything else that can possibly attend an amputation ; therefore, in many ccses, it may be more convenient to remove the whole. In many cases it may be necessary to perform the operation to get at blood-vessels which may be bleeding too freely, for the searching after them may do more mischief than the operation. I have already observed that gunshot wounds do not bleed so freely as those made by cutting instruments, and are therefore attended with less danger of that kind ; however, it may often happen that a considerable "vessel shall be divided, and a considerable bleeding take place; in such cases no time is to be lost: the vessel must be taken up to prevent a greater evil. This operation may in many cases be attended with considerable trouble, especially as it will, in general, be on the field of action. Here the sailor has the advantage of the soldier. It will also be immediately necessary on the field to replace many parts that would destroy the patient if their restoration was delayed, such as the bowels or lungs protruding out of their cavities, or to remove large bodies, such as a piece of shell sticking in the flesh, which would give great pain, and do mischief by moving the whole together. Very little can be done to relieve the brain in such a situation.*

§ 8. Ofthe Treatment ofthe Constitution.

Bleeding is recommended in gunshot wounds, and in such a manner as if of more service in them than wounds in general; but

* [It seems to be now universally admitted by the most esteemed army surgeons that amputation on the field, or very shortly after removal to some fixed hospital, is the most judicious practice, and that the danger is infinitely increased by extending the delay beyond twenty four hours, with a view of obtaining a more favourable opportunity for its performance. The cases which, according to Dr. Hennen, require this relief, are, 1st, where an arm or leg is carried completely off by a round shot; 2d, where there are extensive injuries of the joints; 3d, where there are compound fractures close to the joints, especially if conjoined with lacerated vessels or nerves, or much comminution of the bone, particularly if the femur is the injured bone; 4th, where there is extensive loss of substance or disorganization of the soft parts, by round shot; 5th, where the bones have been fractured or dislocated without rupture of the skin, or great loss of parts, but with great injury or disorganization ofthe ligaments, etc., and injuries ofthe vessels, followed by extensive internal effusions of blood among the soft parts. From the returns ofthe British army in the Peninsula, Mr. Guthrie found that at Toulouse 38 cases out of 48 terminated favourably when amputation was immediately performed ; 41 of these operations were ofthe thigh and leg, and 7 of the arm. Ofthe unfavourable cases, 3 were amputations of ihe thigh, performed as high up as is practicable by the common operation. Of 52 secondary operations, 15 of the superior extremity and 37 of the thigh, as many as 3 ofthe former were lost, and 8 ofthe latter: and altogether of 842 amputations performed at the Hospital Stations between the 21st of June and 24th of December, 1813, the comparative loss of secondary or delayed operations, and of primary or immediate operations, was as follows; Secondary, Primary. Upper extremities . . . 12 to 1 Lower extremities ... 3 to 1 Guthrie on Gunshot Wounds, 2d edit., pp. 150, 220.] OF THE TREATMENT OF GUNSHOT WOUNDS. 541 I do not see this necessity more than in other wounds that have done the same mischief, and where the same inflammation and other consequences are expected. Bleeding is certainly to be used here, as in all wounds where there is a strong and full habit, and where we expect considerable inflammation and symptomatic fever; but if it is such a gunshot wound as not to produce considerable effects, either local or constitutional, I would not bleed, merely because it is a gunshot wound; and from what I have seen, I think that inflammation, etc., does not run so high in these wounds as I should have at first expected. I believe this is the case with all contused wounds where death in the part is a consequence: a contused wound is somewhat similar to the effects of a caustic ; for while the separation of the dead part is forming, the suppurative inflammation is retarded, and therefore not so violent; but this can only be said of those wounds which are not complicated with any other injury except what is produced by the balls passing through soft parts; for if a bone is broken, it will inflame like any other compound fracture. It is often of service, in the time of inflammation, to bleed in the part with leeches or by punctures with a lancet; this helps to empty the vessels of the part, to lessen the inflammation sooner, and of course to promote suppuration; but I must own that bleeding must be used with great caution where inflammation and fever run very hieh, for to reduce the patient equal to the action at the time (which, whether an increased action or an acquired one, is only temporary) will be reducing him often too much for the constitution to support life when this action ceases; for the very worst thing that can happen is the patient's being reduced too low. We often afterwards find more difficulty in keeping up the strength with cordials, bark, etc., than we find in lowering it; and we may avail ourselves ot observing those who have lost considerable quantities of blood from the accident, which is always immediate ; for we find that a second bleeding, by some other accident, although very small in quantity often destroys our patient very quickly; but this will in a great measure depend upon '-he seat of the injury; for in cases of gi eat violence done to some parts of our body bleeding answers better than in others, because the symptoms of dissolution and dissolution itself come on sooner from mischief done to some parts than when 1don" o others A man will bear bleeding better after an amu is none 10 omeis>. ^ _ compound fracture putationof the arm than the leg, neiiti au i v . . . ofthe arm than the leg; he will be^bleed^^^ done to the head, chest, lungs, etc., than either to the arm or leg

We find that ^lX^7^^^^e7^ worse, and are more suscepiiDie ui

parts of ^™™f^™he whole that the decay of animal life is It would appear upon ion ig in a t whose circu. sooner brought o„ whe« tne ^ ^^ .^^ ^ ^ ation is not so strong, cum force of the circulation is far removed. 542 HUNTER ON THE BLOOD. Bark is greatly recommended in gunshot wounds, and with good reason ; but it is ordered indiscriminately to all patients that have received such wounds, whatever the symptoms or constitution of the patient may be. That there is no better medicine for wounds in general, not only when the inflammation is gone off, but in the time of inflammation, if the patient is rather low, and indeed before it comes on, experience daily shows. Bark is to be looked upon as a strengthener or regulator of the system, and an antispasmodic, both of which destroy irritation. The bark and gentle bleedings, when the pulse begins to rise, are the best treatment that I know of in inflammations that arise either from accidents or operations : one lessens the volume of the blood and the increased animal powers at the time, which makes the circulation more free, so that the heart labours less, and simple circulation goes on more freely; the other gives to the blood that which makes it less irritating, makes the blood-vessels do their proper offices, and gives to the nerves their proper sensations, which take off the fever. BIBLIOGRAPHY OF GUNSHOT WOUNDS. Abernethy, J. Surg. Obs. on Tumours and Lumbar Abscesses. 8vo. 1810. ----Allan, Rob., A Syst. of Pathological and Operative Surgery, 3 vols. 8vo. 1821-7.----Andouille, in Mem. de l'Acad. de Chir., 12mo. tom. vi.----Arnal, Mem. sur quelques Particularities des Plaies par Armes a Feu. Univ. Hebd. de Med., 8vo. 1831. tom. iii.----Assalini, P. M.D. Manuale di Chirurgia. 12mo. 1812.----Atkins, J. The Navy Surgeon. 8vo. 1742.

Bagien. Examen des plusieurs parties de la Chirurgie. 8vo. 1756.---- Baldinger, E. G. Introd. in Notitiam Scriptorum Medicinae Militaris, cum Additamentis. 8vo. 17G4.----Ballingall, Sir G. Outlines of Military Surgery. 8vo. 1833.----Bell, Charles. Syst. of Operative Surgery, 2 vols. 8vo. 1807-9, and 2d edit. 1814, in which is incorporated a Treatise on Gunshot Wounds.----Bell, John. A Disc, on the Nature and cure of Wounds, etc., 8vo. 1795. and 3d edit. 1812. p. 169 et seq. ----Bilguer, I. U. Dissert, de Membrorum Amputatione, 1761.---- Blane, Sir Gilbert, M.D. Observ. on the Diseases incident to Seamen, 8vo. 1785.----Boggie, Dr. On Hospital Gangrene, in Med. and Chir. Tr. of Edin., vol. iii.----Bordenave. In Mem. de l'Acad. de Chir., 12mo. tom. vi.----Botallus, Leonard. De Curandis VulneribusSclopettorum, 8vo. 1575.----Boucher. Observ. sur les Plaies d'Amies a Feu, compliquees de fracture aux articulations des Extrem. &c, in Mem. de l'Acad. de Chir., 12mo. v. 279. vi. 109.----Brown, John. A Complete Discourse of Wounds, etc. 1678.----Brunswick, Hieron. The noble Experience of the virtuous Handywarke of Surgerie, fol. 1525.

Cannae. Observ. sur les Plaies d'Armes a. Feu, etc., in Mem. de l'Acad. de Chir. tom. vi.----Carcanus, J. B. De Vulneribus Capitis, 1583. ----Chevalier, Thos. On Gunshot Wounds, small 8vo. 1804.---- Clowes, W. A Proved Practice for all young Chirurgians, concerning BIBLIOGRAPHY OF GUNSHOT WOUNDS. 543 burning with Gunpowder, and Wounds made with Gunshot, Sword, etc., 4to. 1588----Cooper, Sam. Surgical Diet., 8vo. 1812. and last Edit. 1830.----Also, First Lines, etc. Svo. 1813. and last Edit. 1836.

Daignau, M. G. Reflexions Importantes sur le Service des Hopitaux Militaires, 8vo. 1785.----De Conte. In Prix de l'Acad. de Chir., 12mo. tom. viii.----Desport. Traite des Plaies d'Armes a Feu, 12mo. 1749.----Dewar, H. On a particular sort of Gunshot Wound, 8vo. 1815.----Diet, des Sc. Med. (Petit). Art. Depot. Diet, de Med. (Roux). Diet, de Med. et Chir. Prat. (Dupuytren), Art. Abces. Cyc. Pract. Med. (Froudie). Kncyc. Worterb. (Richter), Art. Abscess. ----Dupuy, J. M. Sur les Absces ou Tumeurs purulentes. 1804.---- Dupuytren, Le Baron. Traite Theoretique et Pratique des Blessures par Armes de Guerre, etc., par MM. Paillard et Marx. 2 tom. 8vo. 1834, et Leeons orales (ii. 417). 4 tom. 8vo. 1832-4.

Encycl. Method., Partie Chir., Art. Plaies d'Armes a Feu.

Faure. In Prix de l'Acad. des Chir., 12mo.----Ferrius,Alph. De Tormentariorum sive Arehibusorum Vulnerum Natura et Cur., 2dalmp., 8vo. 1577.----Foudacq, C. F. Reflexions sur les Playes, &c. 12mo. 1753.

Gale, Tho. An Institution of a Chirurgian, conteynynge the sure Grounds and Principles of Chirurgerie. 8vo. 1563.—Also an Enchiridion of Chirurgerie; &c, 8vo. 1563.----Gerard. In Mem.de l'Acad. de Chir. I2mo tom. vi.----Gesscher, Van, Abhandlung von der Nothwendigkeit der Amputation. 1775----Graefe, R. C. F. Normen fur die Ablosung Grosserer Gleidmassen. 4to. 1812.----Guthrie, J. C. On Gunshot Wounds of the Extremities, &c. 8vo. 1815. and 3d Edit. 1827.

Heisterus, Laur. Chirurgie; in welcher AUes was zur Wund-Artzney Gehort, Grundlich abgehandelt ist. (the 3d chap, is devoted to Gunshot Wounds.) 4to. 1719. tr. Lat. 4to. 1743.----Henden, John, M.D. Principles of Military Surgery, 3d Edit. 1829.---Home, Francis, M.D. Medical Facts and Experiments (including a chap, on Gunshot Wounds^) 8vo 1759.----Hutchison, A. Copeland. Some Practical Observon Su eery, 8vo. 1816. and 2d Edit. 1826—Sorae further Ob- ' &c.o Amputation. Svo. 1817----Histoire del'Etatet des Prog. deL Chir Mihtaire en France, pendant les Guerres de la Revolution, par M. Briot. 8vo. 1817.

Jobert, De Lambelle. Plaies d'Armes a Fe#u,&c. 8vo. 1833— Journal de Med. Militaire. 8vo. 1782 et ann. seq. Klohss, K. L. Diss, de Myclitide. Svo. 1820. Yen^^^^in M'6m- d6 VACad' R°y- ^ Med'1828' L 2' 544 HUNTER ON THE BLOOD. ----Laurent, J. Essais sur la Supp. 8vo. 1803.----Leveille, J. F. B. Nouvelle Doct. Chir. (tom. i. chap. viii. p. 436.) 4 tom. 8vo. 1812. ----Le Dran, H. F. Traite ou Reflexions tirees de la Pratique sur les Plaies d'Armes a Feu. 2de edit. 12mo. 1740.----Lizors, I. in Edin. Med. and Surg. Joum. xv. 396. (1819.) on the Pathology of the Nerves in Inflamm.----Lombard, C. A. Dissert, sur l'importance des Evacuans dfins la Cure des Plaies. 8vo. 1783.—Clinique Chir. des Plaies, des Plaies Recentes et des Plaies d'Armes a Feu. 3 tom. 8vo. 1798-1804.---- Lowe, P. M.D., A Discourse ofthe whole Art of Chyrurgerie. 4to. 1597.

Macgrigor, Sir Jas. On the Diseases of the Army, in Med. Chir. Tr. vi. 455.----Maggius, Bart. De Vulnerum Sclopetorum et Bombardarum Curatione Tractatus. 4to. 1552.----Mann, James. Med. Sketches of the Campaigns of 1812, 1813, 1814, &c. 8vo. 1816---- Martiniere, in Mem. de l'Acad. de Chir. 12mo. tom. xi.----Meher, J. Traite des Plaies d'Armes a Feu. 8vo. 1800.----Millengen,J. G. V., M.D. The Army Medical Officer's Manual upon Active Service, <fcc. 8vo. 1819.----Morand, Salv. Opuscules de Chirurgie. 4to. 1768-72. ----Mursinna. Neue Med. Chir. Beobachtungen. Zweiter Thiel, s. 138. 1796.

Neale, H. St. John. Chirurg. Instit. on Gunshot Wounds, &c, 8vo. 1804.

Pare, Amb. Maniere de traiter des Plaies d'Arguebusades et Fleches. 8vo. 1751. Et Opera, cura Guillemeau. fol. 1582.----Paroisse, J. B. Opuscules de Chirurgie, &c. 8vo. 1806----Percy, Le Baron P. F. Manuel du Chirurgien d'Armee, &c. 8vo. 1792.----Plazzonus, Fr. De Vulneribus Sclopetorum, &c. 4to. 1618.

Quercetanus, Jos. Sclopetarius, sive de curandis Vulneribus, &c. 8vo. 1578.

Ranby, J. The Method of treating gunshot wounds, &c. 8vo. 1744.---- Ravaton. Chirurgie d'Armee, &c. 8vo. 1768.—Recueil d'Observ. de Med. des Hosp. Militaires. 4to. l'766-72.----Richerand, Ant. Nosography Chir. (tom. i.) 5eme edit. 4 tom. 8vo. 1821.—Recueil de Mem. de Med. Chir. et Pharm. Milit., &c. redigepar MM. Biron et Foumier et continue par MM. Begin et Etienne. 32 tom. 8vo. 1816-32.---- Richter, A. G. Anfangsgrunde der Wunderzneykunst(bande i.) 7 Bde. 8vo. 4te Aufl. 1804-25.----Rota, J. F. De Tormentariorum sive Archibusorum Vulnerum Natura et Cur. 4to. 1555.----Roux, P. J. Considerations sur les Blesses <Lps Trois Jours. 8vo. 1830.

Schmucker J. L. Chirurgische Wahrnehmungen. 8vo. 1774-89. Vermischte Chir. Schriften, 3 vols. 8vo. 1776-1782.

Theden, J. C. A. Unterricht fur die Unterwundarzte bey Armeen. 8vo. 1782.----Thomassin, M. Diss, sur l'Extraction des Corps etrangers des Plaies. 8vo. 1788.----Thomson, John, M.D. Report of the state ofthe Wounded in Belgium after the Battle of Waterloo. 8vo. 1816. ----Trotter, Thomas, M.D. Medicina Nautica, &c. 3 vols. 8vo. 1797-1803. INFLAMMATION OF THE INTERNAL COATS OF VEINS. 545

Vacher. Sur quelques Particularites concemant les Playes faites par les Armes a Feu. in Mem. de l'Acad. de Chir., &c. 12mo. tom. xi.---- Vigo, John. The most excellent works of Chirurgerye ; tr. by B. Traherom. fol. 1543.

Wedekind. Nachrichten uber das Franzosische, Kriegspitalwesen, Erster Bde. 1797.----Wiseman, Rich. Several Chirurgical Treatises (one of which is ex professo on gunshot wounds), fol. 1676.----Woodall, John. The Surgeon's Mate, &c. 1617; also Viaticum or Pathway to the Surgeon's Chest. 1628. OBSERVATIONS ON THE INFLAMMATION OF THE INTERNAL COATS OF VEINS. Read February 6, 1784. [From the Transactions of a Society for the Improvement of Medical and Chirurgical Knowledge, Vol. I. p. 18, 1793.] The following observations will show that the inside of veins, as well as of all other cavities, is a seat of inflammation and abscess. I have found in all violent inflammations of the cellular membrane, whether spontaneous or in consequence of accident, as in compound fractures, or of surgical operation, as in the removal of an extremity, that the coats of the larger veins, passing through the inflamed part, become also considerably inflamed, and that their inner surfaces take on the adhesive, suppurative, and ulcerative inflammations; for in such inflammations I have found in many places of the veins adhesion, in others matter, and in others ulceration. Under such circumstances the veins would have abscesses formed in them, if the matter did not find in many cases an easy passage to the heart along with the circulating blood, so as to prevent the accumulation ofthe pus; but this ready passage of the matter into the common circulation does not always happen. It is in some cases prevented by the adhesive inflammation taking place in the vein between the place of suppuration and the heart, so that an abscess is formed, as will be further observed. Where the inflammation is most violent there we find the vein most inflamed, there also after suppuration we find the purest pus; and as we trace the vessels from this part, either farther from or nearer to the heart, we find the pus more and more mixed with blood, and having more ofthe coagulated parts of the blood in it. As these appearances are only to be seen in dead bodies, they cannot be described but from thence ; but it is so common a case that I have hardly ever seen an instance of suppuration in any part furnished with large veins where these appearances were not evident after death. I have found them in the bodies of those who have died from amputations, compound fractures, and mortifications. 546 HUNTER ON THE BLOOD. These circumstances all considered lead us to account for a very frequent complaint, that is, an inflamed arm after bleeding: a complaint which has by some been imputed to the wounding of a tendon, because the tendon of the biceps muscle lies under some of those veins in which we often bleed, and when the complaint occurs it is unjustly supposed to arise from want of skill in the operator; by others it has been supposed to arise from the wounding of a nerve; and again it has been laid to the charge of a bad constitution. But if we consider more critically this consequence arising from bleeding, we shall find that it happens frequently after bleeding in veins where no tendon could possibly be wounded, and also where no particular nerve could be in the way. It seems likewise to happen as frequently in constitutions where there is no appearance of want of health, as in those disposed to disease. As a proof of this last, upon bleeding in another vein in the same person, perhaps with a view to assist in the cure of the inflammation arising from the first bleeding, the wound has healed very readily. If we examine the proportion which the number of those inflammations that happen after bleeding bears to those which arise from as slight a wound where no large vein has been injured, and even perhaps where the wound has not been made by so clean a cutting instrument, and the same pains not taken to close it up, we shall find that those from wounded veins are much the most frequent, and that such inflammations seldom or ever happen under the lastmentioned circumstances: therefore we must look for some other cause to explain this effect of bleeding. The manner in which those sore arms come on shows plainly that they arise from the wound not healing by the first intention: for the external wound in most cases first festers or inflames, then suppurates and ulcerates, so that the cavity of the vein becomes impervious. In some this suppuration is only superficial, the vein and parts below having united. In others the skin shall appear to be united, but not close to the vein, so that a small abscess shall form between the skin and the vein: it shall burst and discharge a thin watery fluid, and no further mischief happen : but when this imperfection of union is continued on to the cavity ofthe vein, then the vein inflames both upwards and downwards, and that often for a considerable way, and the surrounding parts join in the inflammation. We find all these variations in different cases: for the disease sometimes goes no further than an inflammation in the vein near to the orifice, which is often resolved; at other times the inflammation is carried further, but suppuration is prevented by the adhesive inflammation taking place in the vein at this part, so as to exclude the suppurative inflammation, and the veins in such cases may be plainly felt, after the surrounding tumefaction has subsided, like hard cords. But this salutary effect is not always produced, and suppuration in the vein is the consequence; but often so confined, INFLAMMATION OF THE INTERNAL COATS OF VEINS. 547 that only a small abscess forms in the cavity ofthe vein near to the orifice. The confinement of the matter in this part of the vein arises from adhesions in the vein a little above and below the orifice. But in many cases the inflammation and suppuration are not confined to this part, from the adhesions not having taken place; for it frequently happens that an abscess is formed, occupying a considerable length of the vein both ways ; and we often have more than one abscess, nay at times there is a series of them, and generally in the direction ofthe vein, between the orifice and the heart; but not always in this course, for we find them sometimes between the wound and the extreme parts. . I have seen from a wound in the foot the vena saphsena inflamed all up the leg and thigh, nearly as high as the groin; and I have been obliged to open a string of abscesses almost through its whole

"°In cases where I have had opportunities of inspecting veins after death in which the inflammation had been violent, upon examining the vein at some distance from this violence, I found the inflammation in the adhesive state; in some places the sides of the vein were adhering, and in others the inner surface of the veins was furred over with a coagulable lymph. Where different abscesses had formed I have always found that the spaces of the vein between them had united by the adhesive inflammation, and it is this union which circumscribes the abscesses. rontw. Upon examining the arm of a man who had died at St. George s Hospital, I found the veins, both below and above the orifice in many places united by the adhesive inflammation. I also found in many parts ofthe veins that suppuration had begun, as we find, on an inflamed surface, but had not yet arrived at ulceration; and in several other places ulceration had taken place, so as to have destroyed that surface next the skin, and a circumscribed abscess was formed. The vein near to the axilla had taken on suppuration tevond which adhesions had not formed, and this had given a free parage for the matter into the circulation, of which most probably

thCInP those cats where larger abscesses have come on than those formed smply from the ulceration of the wound made by the lancet, have aTwa^s found that the vein was afterwards obliterated, having unMand healed up as any other cavity does, so that such naving unueu <um r again, which is patients could never be bled in tne same g esive inflam. a proof that the sides ofthe vein can unite by the adhesive inttam

inflammation of a vein is a common effect after bleeding horses inflammation uj <* operator on this animal which is usually done in the^ L * fae external wound . does not always take sufficient at fir§t for although the yel^ appear to be ago od oneth^J * P P d ^ R thread Qr

Lir! fet if SnoreaxSecutehde wfffi sufficient attention,7! should be 548 HUNTER ON THE BLOOD. inclined to believe that it is the very worst, as it very readily promotes inflammation in the cavity of the vein, either of the adhesive or suppurative kind, according as the ligature does or does not communicate with the cavity. In some of these inflammations of horses I have seen the jugular vein inflamed through its whole length, and all the side of the head has been considerably swelled, and the inflammation carried along the vein quite into the chest. In these cases there is always an abscess formed at the wound, and often several along the vein, as in the human subject; and whenever the complaint is carried so far as this stage, the cavity becomes united at those places by granulations, and the vein is ever after impervious. Many horses die of this disease ; but what is the particular circumstance which occasions their death I have not been able to determine. It may either be that the inflammation extends itself to the heart, or that the matter secreted from the inside of the vein passes along that tube in considerable quantity to the heart, and mixes with the blood. I am inclined to believe that the exposure of cavities of the larger veins in cases of accidents, and also of operations, is often the cause of many of the very extensive inflammations which sometimes attend these cases, and indeed may be the reason why inflammations extend or spread at all beyond the sphere of continued sympathy.* In all cases where inflammation of veins runs high, or extends itself considerably, it is to be expected that the whole system will be affected. For the most part the same kind of affection takes place which arises from other inflammations, with this exception, that where no adhesions of the sides of the veins are formed, or where such adhesions are incomplete, pus passing into the circulation may add to the general disorder, and even render it fatal. In all cases of inflammation where adhesions take place they arise from an extravasation of coagulable lymph; but how such adhesions should take place on the internal surface of veins appears at first sight difficult to conceive, since it is most obvious that the coagulable lymph thrown out by the exhalents on the internal surface of the vein, mixing with the same fluid circulating with the other parts of the blood, would be swept away without producing any effect. But since such adhesions do in fact happen, the coagulable lymph must undergo some change connected with the disposition which produces its extravasation. Although the operation which is the most frequent cause of this complaint is to appearance trifling, yet as it is often of very serious consequence, both to the life ofthe patient and the character of the surgeon, it requires particular attention in the operator to prevent as much as possible an evil of such magnitude. With this view he

* [The frequency of phlebitis, not only after accidents and operations but in puerperal women, has fully confirmed the truth of this conjecture. Inflammation even of the veins of the bones, according to Cruveilhier, is a frequent consequence of operations on these parts.] INFLAMMATION OF THE INTERNAL COATS OF VEINS. 549 will be particularly attentive to the mode of closing the wound and binding up the arm. This is to be done by bringing the two sides of the wound together, that they may unite by the first intention. To accomplish this, let the surgeon, with the thumb of that hand which holds the arm, push the skin towards the orifice, while he draws it on the other side to the same point with the compress; thus the skin will be thrown into folds at the wound over which he is immediately to apply the compress. The compress should be broad, to keep the skin better together; and thick, to make the compression more certain. Another advantage arising from this caution is the prevention of the vein bleeding a second time. I have known an inflammation attack the orifice, which appeared to have arisen from the first union having been broke through, and no second union formed ; but this probably did not arise from the vein being opened a second time, but from the sides of the orifice not having been again brought together. I would recommend a compress of linen or lint, in preference to sticking plaster; for I imagine that the blood drying over, the orifice is a kind of bond of union more natural and effectual than any other application: and this conclusion is drawn from practice ; for I have seen more sore arms in consequence of bleeding where plasters have been afterwards applied, than from any other ; and in cases ofthe compound fracture, when attempted to be cured as a simple fracture, if the wound will allow of being scabbed over, I have seen it always do well; whereas if it has been kept moist, or prevented from evaporating by plasters or other applications, it has always suppu-

When inflammation takes place beyond the orifice, so as to alarm the surgeon, he should immediately make a compress upon the vein at the inflamed part, to make the two sides adhere together; or it they do not adhere, yet simple contact will be sufficient to prevent suppuration in this part ; or if inflammation has gone so far as to make the surgeon suspect that suppuration has taken place, then the compress must be put upon that part of the vein just above the suppuration. This I once practised, and, as I supposed with success. [Few diseases possess more practical or theoret,cal intereat ha" the sub ject of phlebitis ; and yet, clear and satisfactory as Mr..Hunter s obse va ions on the subject are, they do not appear to have attrated much gtenUon until comparatively a recent period. From 1784, the date of Mr. ttuntei: s until c°mP"a« "y M Hodeson's valuable treatise on the diseases of the paper, to 1815, when Mr troag recorded in the arteries and ™n* "^ Generate, does not literature,o this country• B'°h^ \ the complamt, at least with that appear to have been ^VT ^flammation to which the veins are liable, peculiar form f.^X^uu 0ne single exception, are equally silent Tn Ls^IcT^C successive publicatLs, which have since appeared, 550 HUNTER ON THE BLOOD£ of Abemethy, Hodgson, Travers, Carmichael, Arnott, etc., have thrown much light on the pathology of phlebitis, while they have at the same time not only pointed out the frequent complication of phlebitis with other affections, as, for example, accidents and surgical operations, but also that it is often the cause of death in other cases where it was not previously suspected, especially in puerperal women. Among the most remarkable circumstances brought to light in the course of these investigations, must be mentioned the resemblance which the constitutional symptoms attending this form of inflammation bear to those produced by injection of putrid or infectious matters into the current of the blood, and also the frequent occurrence of secondary suppurations in various parts of the body and often in mr.ny parts of the same body. The cause of these peculiarities has not yet been satisfactorily determined, nor has it yet been decided what mode of treatment is most generally eligible. Experience has shown that little reliance is to be placed on the application of compresses above the inflamed part, as advised by the author.] ON INTROSUSCEPTION. [Read August 18, 1789.]

[From the Transactions of a Society for the Improvement of Medical and Chirurgical Knowledge, Vol. I., p. 103. 1793.] Introsusception is a disease produced by the passing of one portion of an intestine into another, and it is commonly, I believe,from the upper passing into the lower part. If the mode of accounting for introsusception, which I am going to offer, be just, it will most frequently happen in the way I have stated, although there is no reason why it may not take place in a contrary direction, in which case the chance of a cure will be increased by the natural actions of the intestinal canal tending to replace the intestine ; and probably from this circumstance it may oftener occur than commonly appears. When the introsusception is downwards it may be called progressive, and when it happens upwards, retrograde. The manner in which it may take place is, by one portion of a loose intestine being contracted, and the part immediately below relaxed and dilated, under which circumstances it might very readily happen, by the contracted portion slipping a little way into that which is dilated; not from any action in either portion of intestine, but from some additional weight in the gut above. How far the peristaltic motion, by pushing the contents on to the contracted parts, may force them into the relaxed, I will not determine, but should rather suppose that it would not. By this mode of accounting for an accidental introsusception, it may take place either upwards or downwards; but if a continuance or an increase of it arises from the action of the intestine, it ON INTROSUSCEPTION. 551 must be when it is downwards, as we actually find to be the case; yet this does not explain those in which a considerable portion of intestine appears to have been carried into the gut below: to understand these we must consider the different parts which form the introsusception. It is made up of three folds of intestine ; the inner, which passes down, and being reflected upwards, forms the second or inverted portion, which being reflected down again, makes the third or containing part, that is, the outermost, which is always in the natural position. The outward fold is the only one which is active, the inverted portion being perfectly passive, and squeezed down by the outer, which inverts more of itself, so that the angle of inversion in this case is always at the angle of reflection of the outer into the middle portion or inverted one, while the innermost is drawn in. From this we can readily see how an introsusception, once begun, may have any length of gut drawn in. The external portion acting upon the other folds in the same way as upon any extraneous matter, will, by its peristaltic motion, urge them further; and, if any extraneous substance is detained in the cavity of the inner portion, that part will become a fixed point for the outer or containing'intestine to act upon. Thus it will be squeezed on, till at last the mesentery, preventing more of the innermost part from being drawn in, will act as a kind of stay, yet without entirely hindering the inverted outer fold from going still further. For it being the middle fold that is acted upon by the outer, and this action continuing after the inner portion becomes fixed, the gut is thrown into folds upon itself; so that a foot in length of intestine shall form an introsusception of not more than three inches long. The different appearances which I have described as taking place in an introsusception are distinctly seen in Plate IV., fig. 4., in which the different folds of intestine are exposed. I have asserted that the outer portion of intestine was alone active in augmenting the disease when once begun, but if the inner one was capable of equal action in its natural direction, the effect would be the same, that of endeavouring to invert itself, as in a prolapsus ani; the outer and inner portions, by their action, would tend to draw in more of the gut, while the intermediate part only would, by its action, have a contrary tendency. . The action of the abdominal muscles cannot assist in eithei formino- or continuing this disease, as it must compress equally both above and below, although it is capable of producing the prolapsus

"in cases where the introsusception begins at the valve of the colon, and invers that intestine, we find the ileum is no at all affected, which proves that the mesentery, by acting as a stay, prevents its

inFromnthe natural attachment of the mesentery to the intestines, u at thP first view of the subject, conceive it impossible ZZyone porta rf gut to get far wkin another, as the greater 552 HUNTER ON THE BLOOD. extent of mesentery that is carried in along with it would render its further entrance more and more difficult, and we should expect this difficulty to be greater in the large intestines than in the small, as being more closely confined to their situation : yet the largest introsusception of any known was in the colon, as related by Mr. Whately.* The introsusception appeared to have begun at the insertion of the ileum into the colon, and to have carried in the caecum with its appendix. The ileum passed on into the colon, till the whole of the ascending colon, the transverse arch and descending colon, were carried into the sigmoid flexure and rectum. The valve of the colon being the leading part, it at last got as low as the anus; and when the person went to stool he only emptied the ileum, for one half of the large intestines being filled up by the other, the ileum alone, which passed through the centre, discharged its contents. Since that time the following case has occurred, which is in many respects similar; the patient was attended by Dr. Ash, and the body inspected after death by Mr. Home. A. B., aged nine months, a large, healthy, well-looking child, who, as far as appeared, had never been indisposed from his birth, was seized with a strong spasm, stretching himself out suddenly, without having any symptoms of previous ailment. Either during the spasm, or immediately after it, he passed a very large loose stool, and after that discharged at intervals small quantities of mucous slime, covered over with little specks of recent fluid blood. Dr. Ash visited him four or five hours after this attack, and found him in all other respects perfectly well; the child sucked heartily, but Dr. Ash, on observing his pulse to be less quick than is usual in children so young, his heat to be rather below the common standard, and, added to these, the small mucous and bloody discharges, suspected that mortification had taken place in the bowels, without being able to guess at the cause, as the child had laboured under no previous indisposition. In this uncertain situation various means of relief were attempted by purgatives, fomentations, the warm bath, and different kind of clysters, but without any good effect. On his first examination of the abdomen he felt (or thought he felt) a deepseated fulness or hardness under the left hypochondrium; blisters were applied to the part, and every possible means attempted, without obtaining any evacuation by stool, or any other apparent relief; his strength gradually sunk, and his pulse became gradually weaker, although he continued to take the breast eagerly till within a few hours of his death, which happened just sixty hours after the first spasmodic attack. The following were the appearances found in the dead body. Upon opening the abdomen the small intestines, considerably distended with fluid contents, occupied so much of the cavity as to prevent any of the other viscera from being seen, and the mesentery was so Vide Philos. Trans., vol. lxxvi., page 305. ON INTROSUSCEPTION. 553 much confined that the convolutions of the small intestines could not be readily followed. This confinement was found to arise from an introsusception ofthe ileum and its mesentery, together with the caecum and ascending colon into the descending part of the sigmoid flexure ofthe colon, the mesentery of the ileum being drawn up so obliquely across the root of the mesentery as to prevent the jejunum from having its usual freedom of attachment. The only part ofthe colon which could be seen was the sigmoid flexure, in which was distinctly to be felt a hard substance, consisting ofthe ileum and inverted colon. These parts being removed, for the purpose of a more accurate inspection of them, the sigmoid flexure ofthe colon was laid open, and was discovered to contain the cascum and colon in an inverted state. The internal surface of these, when exposed, were found to have put on a dark red appearance, approaching to black; the whole appearing like a solid substance, rounded at the end, hanging loose into the descending colon, and about four inches long. Upon dividing the inverted colon, the ileum and appendix caeci were seen lying close to each other, and their two openings found on the rounded end of the inverted colon, leading directly into the sigmoid flexure; the portion of the ileum was a little twisted, but not in the least corrugated, it was rather stretched, and much pressed against the appendix caeci and its own mesentery by the surrounding colon, and a convolution of the appendix near the termination was so much pressed against the ileum as to make a mark upon it, and probably had compressed its sides so as to prevent anything from passing. The portion of ileum was about four inches long. The inverted colon had drawn in the meso-colon, and a portion ofthe omentum that was attached to the transverse arch. The portion ofthe colon near the valve, which formed the extremity of the inverted part, was much thickened in its substance by the effects of inflammation, being four or five times its natural thickness ; it was a good deal corrugated, or folded upon itself, the folds at this part seemed to adhere to one another, and form one mass. The inflammation and thickening only extending two inches, the gut becoming gradually thinner till it was of its natural thickness and appearance; so that what was only four inches in length of introsusception, contained a considerably greater length of intestine The sigmoid flexure, which was the containing intestine had the natural Appearance, but was dilated or relaxed; and the other contents of the abdomen were in a natural state, nor had the child any other apparent disease. A representation of the parts may be

From the account I have given of introsusception, it does not seem nrobable that it should be of the retrograde kind, unless from ■ anSS.of the peristaltic motion, which could only continue for a short time, and the natural motion being restored, a cure would

P^,diseeaLe1uTpmpens most fre^ently in the first fifteen years of 554 HUNTER ON THE BLOOD. life, not occurring so commonly in older people, neither does it, I believe, ever take place in the colon itself, although we find that gut affected by it.* An introsusception can never be perfectly known till after death ; but where there are violent affections of the bowels, attended with constipation, we have reason, from the cases which have been examined in the dead body, to suppose that this disease may be the cause of them : there are, however, so many other diseases which produce the same symptoms, that nothing can be ascertained. But if an introsusception is suspected, it will be proper in the mode of treatment to suppose it to be of the progressive kind. In the treatment of this disease various methods have been proposed : bleeding, to lessen the inflammation that might be brought on, and quicksilver, to remove the cause, are the most obvious, and the means that are usually recommended. Quicksilver would have little effect, either in one way or other, if the introsusception was downward; for it is to be supposed that it would easily make its way through the innermost contained gut, and if it should be stopped in its passage, it would, by increasing its size, become a cause (as before observed) of assisting the disease. In cases of the retrograde kind, quicksilver, assisted by the peristaltic motion, might be expected to press the introsusception back; but even under such circumstances it might get between the containing and inverted gut into the angle of reflection, and by pushing it further on increase the disease it is intended to cure. From the account I have given of the manner in which it is produced, I should propose the following treatment in cases of progressive introsusception. Everything that can increase the action of the intestine downwards is to be particularly avoided, as tending to increase the peristaltic motion of the outer containing gut, and thus to continue the disease. Medicine can never come in contact with the outer fold, and having passed the inner, can only acton the outer below, therefore cannot immediately affect that portion ofthe outer which contains the introsusception ; but we must suppose that whatever affects or comes in contact with the larger portion ofthe canal, so as to throw it into action, will also affect by sympathy any part that may escape such application. I should therefore advise giving vomits, with a view to invert the peristaltic motion of the containing gut, which will have a tendency to bring the intestines into their natural situation.

* A prolapsus ani is, in some respects, similar to an introsusception, and may possibly begin in the same way, but is continued by the action of the abdominal muscles, never by the action of the gut itself. It differs from introsusception as not being contained in a gut; for, instead of having an inclosing gut inverting itself by its own action, there is an inclosed gut protruded by the action of the abdominal muscles and the passing ofthe faeces through it, and the point of inversion is at the extremity of the protrusion, and as it inverts it pushes out of the body. ON INTROSUSCEPTION. 555 If this practice should not succeed, it might be proper to consider it as a retrograde introsusception, and by administering purges endeavour to increase the peristaltic motion downwards.

SUPPLEMENT TO THE PAPER UPOJV INTROSUSCEPTION. BY SIR EVERARD HOME, BART. The following case of introsusception upwards has been communicated to me by the late Mr. Smith, surgeon at Bristol; in whose collection of morbid preparations I saw the parts, which had been removed from the dead body, and preserved in spirits. That the introsusception was upwards is sufficiently ascertained from the preparation. The particulars of the case, as far as they came to the knowledge of Mr. Smith, who examined the body after death, were as follow: A cabin-boy, belonging to one of the ships lying in Bristol harbour, was corrected by his master for some misconduct, at which the boy was very much exasperated, and in the heat of his passion swallowed some arsenic, which had been laid in different parts of the ship to poison rats. He was attacked with violent pain in the stomach and intestines, attended with excessive vomiting, and expired before any medical assistance could be procured. Upon inspection of the body, the internal surface of the stomach was found inflamed to a very great degree, the inflammation extending a considerable way along the track of the small intestines, and in the ileum there was discovered an introsusception of above two inches long, formed by a portion of the lower part of the gut having been inverted, and pushed into that immediately above n. On slitting up the intestine, to examine the introsusception more accurately, a long round worm was found coiled round the projecting introsuscepted part, and is preserved in that situation in the preparation. The circumstances under which the round worm was found determines the kind of introsusception, since I have observed that species of worm more commonly in the upper portion of the small intestines, in which situation, having been disturbed by the effects of the arsenic, it had consequently moved, to get at a greater distance from the poison. It is likewise probable, from the coming on of inflammation, that vomiting, an immediate effect of the poison, by which the peristaltic motion was inverted, and the introsusception produced, had been followed by a contrary action, or disposition to purging, by which the worm, being hurried along till it came to the introsuscepted part, was there stopped, and in the endeavour to extricate itself had twined round the projecting part, in which situation it died. If the introsusception had been downwards, the worm could not have been in that situation. It is probable that if the boy had outlived the immediate effects of the a-senic and the peristaltic motion had perfectly recovered itself the introsusception would have been by that means unfolded. 556 HUNTER ON THE BLOOD. AN ACCOUNT OF MR. HUNTER'S METHOD OF PER- FORMING THE OPERATION FOR THE CURE OF THE POPLITEAL ANEURISM.* BY SIR EVERARD HOME, BART. [From the Transactions of a Society for the Improvement of Medical and Chirurgical Knowledge, Vol. I., p. 138. 1793.]

The popliteal aneurism being a disease which frequently occurs and generally proves fatal, unless some means are taken to prevent it, we cannot be surprised that it has attracted the attention and called forth the exertions of the ablest surgeons in this country to discover some method of cure. Experience has shown that all the modes hitherto practised are exceedingly precarious, being rarely attended with success, and the death of the patient being commonly a consequence of a failure of the operation : a circumstance which has led some surgeons of great eminence to prefer the amputation of the limb in all such cases. Mr. Hunter, who has repeatedly performed the operation for the aneurism, finding that it in general fails, and having likewise observed that the removal of a limb so high up, from a person in health, seldom succeeds in preserving life, and when it does, leaves the patient disabled, was excited to consider this disease with more than ordinary attention. The result has been a mode of practice that appears to possess many advantages over those hitherto recommended, and to be an improvement in the practical part of surgery ; at least it is from this idea being strongly impressed on my mind that I am induced to communicate it to this Society, as Mr. Hunter is too much engaged to permit his taking that task upon himself. An aneurism is a preternatural dilatation of a portion of an artery, and in general it is a very small part of the arterial coats which is thus affected, The dilatation is commonly on one side only, and when once begun gradually enlarges, from the force of the heart propelling the blood against the dilated part. Thus in time a sac is formed, which being in some measure out of the direct course of the circulation, the blood, where it is at the greatest distance from the channel of the artery, coagulates and forms layers or strata upon the inside of this sac. As the enlargement of the sac depends entirely on the force with which the blood is acted on by the heart, it does not, as at first, continue to swell out at right angles from the side of the artery, but is increased in a diagonal line between that and the course ofthe artery itself, from the force of

* [Mr. Hunter's claim to the merit of this discovery has been fully vindicated in the course of his Life, page 72-4. See also the description to PL IV. fig. \ and 2 ; and the London Medical Journal, vol. ix.J ON THE CURE OF THE POPLITEAL ANEURISM. 557 the blood being applied in that direction; so that the sac is protruded along the outside of the artery, and by its pressure upon it obliterates, in many instances, the lower orifice, which communicates with the artery, and produces a total stagnation of the blood in the sac. If the coats of an artery are examined in the commencement of this disease, the first appearance is a loss of the natural lustre and transparency of its internal membrane, that becoming opake, afterwards thicker, acquiring a leather-like appearance; and when the sac becomes larger the coats retain no longer a resemblance to those of an artery, but have more that of a membranous bag, communicating laterally with the artery by a rounded orifice, of different sizes, the margin of which resembles the internal membrane of an artery, in a thickened state ; but beyond that gradually degenerates into a membranous substance. The popliteal aneurism, which we are at present to consider, is the disease above mentioned, affecting the trunk of the popliteal artery, which runs down between the two hamstrings of the thigh. From the situation of the tumour, on whatever side ofthe artery the dilatation is produced, it will be distinctly felt, in the hollow between the hamstrings, and will be readily ascertained by a pulsation to be felt in every part of the tumour: it seems to be one of the most frequent situations of aneurism ; and though it may be difficult to ascertain whether it occurs so commonly as in the aorta itself, it is certainly found oftener in this artery than in any other branch which the aorta sends off.* This circumstance, as far as I know, has not hitherto been accounted for, and what is rather curious, in many recent instances of this disease, the patients have been coachmen and postilions.f The popliteal aneurism has been

* [The following table,a from Mr. Hodgson's Treatise on the Diseases of Arteries and Veins, p. 87, exhibits the comparative frequency of aneurisms in the different arteries ofthe body :— Ofthe ascending aorta, the arteria innominata and the arch ofthe aorta............................ Arch ofthe descending aorta......................... ------carotid artery......................•............ ______subclavian and axillary arteries......... ------inguinal arteries............................... ______femoral and popliteal arteries............. Males. Females. Total. 16 5 21 7 1 8 2 2 5 ... 5 12 12 14 1 15 56 7 G3 t Moreacrni and his friends found aneurisms of the aorta more frequently in guL^Ktiboys and other persons who sit . joo-t^co-u no.* «^,

W$S« wetSTr tt o° Sorter USted by the different positions of theTg anTSgh, and the obstruction which the circulation must inevitably

a [This table does not include aneurisms arising from wounded arteries, or aneurisms from anastomosis.] 558 HUNTER ON THE BLOOD. in general supposed to arise from a weakness in the coats of the artery, independent of the presence of disease: if this were true, we might reasonably conclude that, except in the part preternaturally dilated, the vessel remained in a sound state, which would naturally suggest the mode of practice generally recommended, viz., opening the sac, tying up the artery above and below it, leaving the bag to suppurate, and afterwards heal up like any common sore. Mr. Hunter finding an alteration of structure in the coats ofthe artery previous to its dilatation, and that the artery immediately above the sac seldom unites when tied up in the operation for the aneurism, so that as soon as the ligature comes away, the secondary bleeding destroys the patient, was led to conclude that a previous disease took place in the coats of the artery, in consequence of which it admitted of dilatation capable of producing aneurism. But not satisfied with the experiments on frogs, given by Haller in support of the opinion that weakness alone was sufficient to produce the dilatation, he resolved to try the result in a quadruped, which, from the vessels being very similar in their structure to those of the human subject, would be more likely to ascertain the truth or fallacy of Haller's opinion. That the experiment might have as much as possible the chances most likely to produce aneurism, the carotid artery, as being near the heart, was selected for that purpose. Mr. Hunter having laid bare the carotid artery of a dog, for above an inch in length, having removed its external coat, and afterwards dissected off the other coats, layer after layer, till what remained was so thin that the blood was plainly to be seen through it, left the dog to himself. In about three weeks the dog was killed and the parts examined, when it appeared that the two sides of the wound having closed upon the artery, the whole of the surrounding parts were consolidated, forming a strong bond of union, and the artery itself was neither increased nor diminished in size.

meet with in that artery, when the limb is bent, we see a probable reason why it should be more liable to disease than any of the other ramifications of the aorta; especially when it is found that aneurisms in the aorta itself are most frequent at the curve of that artery. If this observation is allowed to have any weight, the reason will be evident why the disease should occur more frequently in coachmen and postilions; for their knees being almost constantly in a bent state, from the necessary exertions of their bodies in their different occupations, and from the violent motion of their horses and carriages, the circulation must often be considerably increased; while the branches immediately below the popliteal artery will be in some measure obstructed by the action of the gastrocnemii and solaei muscles,in steadying the body in the stirrup, or against the foot-board ofthe carriage. The unfavourable circumstances respecting the popliteal artery, do not in common life seem of themselves capable of producing disease, but when increased to a great degree, as in the occupations of coachmen and postilions. They, at the same time, from want of sufficient exercise, have their iegs weaker and less healthy than the rest of the body ; and the cases to be mentioned appear still further to prove, that these circumstances may produce such a state of the artery at this part, as to dispose to the formation of aneurism. ON THE CURE OF THE POPLITEAL ANEURISM. 559 This experiment appeared very conclusive, as the coats of the ■ artery were weakened to a much greater degree, without dilatation, than can ever happen from accident in the living body, independent of morbid affection. But it was objected, on the other hand, that the parts, having been left to themselves, immediately closed upon the weakened portion of the artery, and, being cemented together by the coagulated blood, effectually secured it against any dilatation. To try the force of this objection, I made the following experiment. I laid bare the femoral artery of a dog, about two inches below Poupart's ligament, for about an inch in length, and dissected off the coats till the hemorrhage from the vasa vasorum was considerable, and the circulating blood was distinctly seen through the internal membrane of the artery. The hemorrhage soon stopped by exposure, the surface was wiped dry, and afterwards covered with a dossil of lint, to prevent the sides of the wound from uniting. 1 he dog continued very well, and the wound healed up from the bottom; after six weeks the dog was killed, and the artery was injected, that it might be examined with greater accuracy. It was not perceptibly enlarged or diminished, and its coats at this part had recovered their natural thickness and appearance. The results of these experiments confirmed Mr. Hunter in his opinion that the artery, in cases of aneurism is in a diseased state andTd him to believe that the disease often extends along the artery for some way from the sac; and that the cause of fa.lurein ffie common operation arises from tying a diseased artery, wh ch is incapable of union, in the time necessary for the separating of the

^^hTfemoral and popliteal arteries are portions of the same trunk, present nTthemselves on different sides of the thigh, and are readily come at Tn either situation; but where the artery is passing from the one side to the other, it is more buried in the surrounding parts, nnd rannotbe exposed without some difficulty. . In performing"the operation for the popliteal aneurism especially wht^Tumogr is large, the ligature is: common y appJied.ori the arteryat that part wh^ performing the operation will be found n q ^^ afterwards the artery extends above the> sac, lor i i J remaining to give way, there will not be a sufficient lengn o^ ^ allow of its being again secured "^e ham 10 / up, through the insertion ^^W?™^«h]e partPof the of it where it is sound, becomes a ve.y s f h h- h operation; and to make,>n« ^"Kbreaking new to get at and secure the femoral arieiy, erations. ground: a thing to ^^£'iervaLs, was led to Mr. Hunter, from h^m.f nXarterv should be taken up in the propose, that in this operatwn the^ from the diseased part? anterior part of the thigh, at wme^ ^ admU Qf the &rtery so as to diminish the risKedhouid ^ ^ accident happen< The being more reaauy &^ 560 HUNTER ON THE BLOOD. force of the circulation being thus taken off from the aneurismal sac, the progress of the disease would be stopped; and he thought it probable, that if the parts were left to themselves, the sac, with its contents, might be absorbed, and the wholeof the tumour removed, which would render any opening into the sac unnecessary. Upon this principle Mr. Hunter performed the operation at St. George's Hospital. The patient was a coachman, forty-five years of age ; he was admitted into the hospital in December, 1785, with a popliteal aneurism, which he had first perceived three years previous to his admission, and had observed it gradually to increase during the whole of that period. It was so large as to distend the two hamstrings laterally, and make a very considerable rising between them ; the pulsation was very distinct, and to be felt on every side of the tumour. The leg and foot of that side were so swelled as to be much thicker than the other, and were of a mottled brown colour; the swelling was not of the oedematous kind, but felt firm and brawny, probably from the extravasation of coagulable lymph ; the leg retained its natural shape, excepting that it was larger. Previous to performing the operation, a tourniquet was applied upon the upper part of the thigh, but not tightened, that the parts might be left as much in their natural situation as possible. The operation was begun by making an incision on the anterior and inner part of the thigh, rather below its middle, which incision was continued obliquely across the inner edge of thesartorius muscle, and made large, to give room for the better performing of whatever might be thought necessary in the course of the operation. The fascia which covers the artery was then laid bare about three inches in length, after which the artery itself was plainly felt. A slight incision, about an inch long, was then made through this fascia, along the side of the vessel, and the fascia dissected off: by this means the artery was exposed. Having disengaged the artery from its lateral connections by the knife, and from the other adhering parts by the help of a thin spatula, a double ligature was passed behind it, by means of an eyed probe. The doubling of the ligature brought through by the probe, was cut so as to form two separate ligatures. The artery was now tied by both these ligatures, but so slightly as only to compress the sides together. A similar application of ligature was made a little lower. The reason for having four ligatures was to compress such a length of artery as might make up for the want of tightness, it being wished to avoid great pressure on the vessel at any one part. The ends of the ligatures were carried directly out at the wound, the sides of which were now brought together, and supported by sticking-plaster and a linen roller, that they might unite by the first intention. The limb was found, some hours after the operation, not only to retain its natural heat, but even to be warmer than the other leg. The second day after the operation the brawny firmness of the leg was considerably diminished, it was become soft, loose, and a good ON THE CURE OF THE POPLITEAL ANEURISM. 561 deal smaller, and the aneurismal tumour had lost more than onethird of its size. Nothing could show more plainly the action of the absorbents than the change the leg had undergone in so short a time; the diminution of the tumour probably arising from the fluid blood which it contained having passed into collateral branches, or into the tibial artery. . The fourth day, on the removal of the dressings, the edges ol the wound were found united through its whole length, excepting where prevented by the ligatures ; there was neither pain nor tumefaction in the part; but the aneurismal tumour was the same as on

lhOn6the ninT day after the operation there was a considerable discharge of blood from the part where the ligatures passed out; a tourniquet was therefore applied on the artery above which stopped the bleeding; and although the tourniquet was taken off a ewP hou a ter, noT> lood followed. The head of a roller was then plLupon th; wound, in the direction of the artery, and over £ the tourniquet, which was not, however, tightened more than was thought sufficient to take off the impetus of the blood in that

P0On0nth°e temrdZy appearances were much the same only that between the compress and the knee there appeared a little fulness hke beginning inflammation. On the eleventh day this was gone off anion tfi fifteenth some ofthe ligatures came J way, follow^ bv a small discharge of matter, the tumour in the ham being less ened On the seventeenth day the parts surrounding the aneurismal tumour were more reduced and pliable, so that it was distinctly

t0 About* the latter end of January, 1786, six weeks after the operatiof the pati n Went out of the hospital, the tumour at that time bem'g somewhat lessened, and rather firmer to the feel. He w ucmg ^.mij^ u^cT^toi onr-p everv week, and, in the meanwhich in most cases h" a good eflect. decreased, and About the middle of Febiuary the ^ ^ was become still firmer. Mai en i the cicatrized, broke out again and ihe^patent^ ^ ^ hospital. About the 8th ot *f ^fl tion appeared upon the thePligature came awg and ^tZlTu^ a sma/abscess upper part of thfJ™^^ the old cicatrix, at which opening broke at some distance irom ligature were ob- ,ome matter was «-c^ served. Several small threadier-, ^ ^ ^ .from the old ^/c, and the swejin before> attended with conswelled again to, a g^^- of July, a piece of ligature, about siderable pain. In the ^ f after 4ich the swelling went off one inch in length, came away, 562 HUNTER ON THE BLOOD. entirely, and he left the hospital the 8th of July, at which time there remained no appearance of tumour in the ham, he being in every respect well. After leaving the hospital the man returned to his usual occupation of driving a hackney coach, and being, from the nature of his employment, much exposed to cold, in March, 1787, he was seized with a fever of the remittent kind, which carried him off. He had not made any complaint of the limb on which the operation had been performed from the time of his leaving the hospital. He died on the 1st of April, 1787, fifteen months after the operation, and leave was procured, with some trouble and considerable expense, to examine the limb seven days after death, at which time it was entirely free from putrefaction. The cicatrix on the anterior part of the thigh was scarcely discernible, but the parts under it felt hard. The ham had no appearance of tumour, and was to the eye exactly like that of the other limb; there was, however, a solid tumour perceptible to the touch, filling up the hollow between the two angles of the thigh-bone. The femoral artery and vein were taken out above the giving off the branch called profunda, and a little below the division into the arteriae tibiales and interossea. The arteries and veins that were pervious being injected, the whole was carefully dissected. The femoral artery was impervious from its giving off the arteria profunda as low as the part included in the ligature, and at that part there was an ossification for about an inch and a half along the course of the artery, of an oval form, the rim of which was solid, becoming thinner towards the centre, and not bony, but ligamentous. Below this part the femoral artery was pervious down to the aneurismal sac, and contained blood, but did not communicate with the sac itself, having become impervious just at the entrance. What remained ofthe aneurismal sac was somewhat larger than a hen's egg, but more oblong, and a little flattened, extending along the artery below for some way, the blood pressing with greater force in that direction, and distending that part so as in some measure to give the appearance of a separate hag. The sac was perfectly circumscribed, not having the smallest remains of the lower orifice into the popliteal artery ; whether this arose from the artery being pressed upon by the inferior portion of the sac, as appears to be the case in common, or was in consequence of the sac contracting after the operation, I will not pretend to determine; but it contained a solid coagulum of blood, which adhered to its internal surface. A section made of this coagulum appeared to be composed of concentric lamella?, uniform in colour and consistence. The popliteal artery, a little way below the aneurismal sac, was joined by a small branch, very much contracted, which must have arisen either from the profunda, or the trunk of the femoral artery. About two inches below the sac, the popliteal gave off, or divided into the tibiales. The profunda was of the usual size, but a good deal ossified for ON THE CURE OF THE POPLITEAL ANEURISM. 563 some length after leaving the femoral artery; the two tibials, where they go off from the popliteal, were in the same state. The trunk of the femoral vein, where it passed along the side of the tumour, must have been obliterated, for at this part it appeared to send off three equal-sized branches, passing over different parts of the aneurismal sac ; these must have been dilated branches, none of them having the course which the trunk of the vein should have pursued. These appearances throw some light upon the changes which took place in the limb after the operation. The ligature upon the femoral artery impeded the passage of the blood into the sac so much as to allow its contents to coagulate, and render the opening into it from the artery impervious. By this a stop was only put to the increase ofthe tumour; its reduction to the size met with in the dead body, must have been the effect of absorption. The conclusion to be drawn from the above account appears a very important one, viz., that simply taking off the force of the circulation from the aneurismal artery, is sufficient to effect a cure of the disease, or at least to put a stop to its progress, and leave the parts in a situation from which the actions of the animal ceconomy are capable of restoring them to a natural state. In confirmation of the cure of aneurism depending on taking off the force ofthe circulation, I shall mention a case of aneurism that recovered without an operation, and in which the mode of recovery depended upon the same principle. The aneurism was in the femoral artery, and the swelling appeared upon the anterior part of the thigh, a little above the middle, extending upwards nearly to Poupart's ligament; an attempt was made, by compressing the artery above the tumour, by means of an instrument somewhat resembling a steel truss, to give the blood in the sac a chance of coagulating, and by that means put a stop to the progress of the disease. But from the pain which it occasioned, every attempt to make a permanent compression on the artery proved ineffectual. The tumour increased to a very considerable size, a great degree of inflammation and swelling took place in the sac and common integuments, and mortification appeared to be coming on the skin. While in this state no pulsation could be felt in the "tumour, or the artery immediately above it, so that the steps preceding mortification had taken place,* which put a stop to the dilatation of the sac, and all its consequences. From tne time the pulsation in the sac stopped, the inflammation and swelling subsided, although very slowly ; and as the tumour diminished it became firm and solid, and the patient got perfectly well. It appears from these cases that surgeons have laid too much * On examining the bodies of those who die in consequence of mortifications, the artery leading to the mortified part is completely stopped up with a firin coagTum for seferal inches in length ; Un. most precede the truncation, and seems intended to prevent hemorrhage.—From Mr. Hunter s Lectures. 564 HUNTER ON THE BLOOD. stress upon the supposed necessity of large collateral branches, to insure the success of this operation ; an opinion which must have arisen from anatomical knowledge, rather than observations made from practice. The second time Mr. Hunter performed this operation was upon a trooper about forty years of age. A toui'niquet having been loosely applied upon the thigh, the operation was begun by a longitudinal incision through the integuments, and the artery and vein were exposed, as in the former case, but not taken up with a number of ligatures, for nothing appeared to have been gained by such practice, and the bad effects of it were obvious in the progress of the cure : they were included in one strong ligature, sufficiently tight to prevent the pulsation in the sac without injuring the coats of the vessels. The ends of the ligature were brought out at the wound, which was in this case dressed from the bottom. The advantages proposed by this treatment were, to be able to see the progress of the cure, and to come readily at the artery, if any unfavourable circumstance occurred, since the abscesses in the former case were suspected to have arisen from the mode of healing. After the operation, the superficial veins of the leg became exceedingly turgid and numerous, and the limb, although warm, became rather less so than the other, particularly the foot. The next day the leg was swelled, and the heat 12° lower than the other; the second day it exceeded the other 5°; and on the fourth day the two limbs were equally warm : the patient was free from fever. On the fourteenth day the ligature came away, and the tourniquet was loosely applied, as a precaution against bleeding; the sartorius muscle was a good deal enlarged, and covered the passage down to the artery, so as to prevent the matter from having a free discharge, a good deal being confined behind it, and with difficulty squeezed out at each dressing. On the nineteenth day there was a hemorrhage from behind the muscle, the swelling of which rendered it nearly as difficult to come at the vessel, as if the parts had healed by the first intention : the bleeding was stopped by applying pressure, after having lost about ten or twelve ounces. On the twentieth there was a slight bleeding, which was readily stopped : yet five hours afterwards the femoral artery gave way, and he lost about one pound of blood before the tourniquet was applied. The artery was laid bare, and tied a little higher up, the patient being very weak and low : in this state he continued till the twenty-third day without bleeding, when it bled again from a small vessel. On the twenty-sixth, a considerable hemorrhage having taken place, he became faint, then delirious, had vomiting with hiccough, and died the same day. Upon examining the limb, sinuses were discovered, both upwards and downwards, in the direction ofthe artery and sartorius muscle, besides smaller ones in different directions. ON THE CURE OF THE POPLITEAL ANEURISM. 565

In this case the bad consequences and death of the patient do not appear to have arisen from the operation, but were entirely the result ofthe mode of treatment afterwards, as will appear from the following cases. The third patient operated upon by Mr. Hunter was a postilion, thirty-five years old. Compression upon the femoral artery was attempted, but the pain was so great that it could not be continued. In performing the operation only one ligature was used, and the parts healed by the first intention. On the seventh day after the operation the first dressings were removed, and a good deal of matter came out by the side of the ligature. On the fourteenth the ligature came away, and in four weeks the wound healed. The sac in the ham, from being chafed previous to the operation burst at this time, but healed up like any other sore, and at the end of three months he was perfectly recovered. Mr. Hunter's fourth patient was a coachman, thirty-six years old. The tumour in the ham was not very large, and situated lower down than usual, the whole leg being swelled, and the veins turgid. The pain he complained of was exceedingly violent, but being in a very bad state of health an operation was not thought advisable, and gentle pressure on the tumour was attempted; but, from the pain it occasioned, the operation was had recourse to, as the only chance of saving his life, although, from the irritable state in which he then was, even that seemed a forlorn hope. In performing the operation the vein was not included in the ligature; but in other respects it was similar to the former.* Immediately after the operation the limb was benumbed, and continued so for some time, which was singular, as the nerve had not been included. It became, on the same day, four or five degrees hotter than the other leg, and continued so for the first fourteen days, when the temperature became the same as that of the other limb. The sixth day the first dressings were removed, and the skin was united everywhere except at the passage of the ligature. It remained in this state till the twenty-first, when the cicatrix inflamed and ulcerated, with a sloughy appearance, and hardness up the thigh. On the twenty-ninth day the ligature came away; the sore now put on a better appearance, suppuration took place where the hardness had been in the course of the artery, and the parts became softer, the discharge gradually diminished, and in the seventh week the wound was healed. But it did not continue so : for in three days an inflammation took

* [If from this expression we are to infer that the artery and vein were included in the same lio-ature in the other cases, it readily accounts for the troublesome effects which ensued in those operations.] 566 HUNTER ON THE BLOOD. place, and an abscess formed, and burst at the cicatrix, which also healed up. About the end of the tenth week he was attacked with a very severe remitting fever, which lasted fourteen days, and left him much reduced ; but in the fourteenth week he was so far recovered as to leave the hospital, and go into the country for the recovery of his health. The fifth patient upon whom Mr. Hunter performed this operation was Joseph Caswell, aged forty-two, a man not accustomed to horse exercise or any mode of life which could in the least assist in producing the disease. The aneurism was in the ham of the left leg. . In performing the operation the artery alone was included in a strong single ligature, and the wound was healed by the first intention, leaving a passage for the ligature. The local inflammation was extremely small, and consequently attended with little sympathetic fever. The ligature came away the eleventh day, and in five weeks he went into the country, able to walk with a stick, the wound perfectly healed. In this case the heat of the two legs was carefully examined twice a day, from the second to the ninth after the operation, and the limb operated upon was uniformly colder than the other. He came to town six months after the operation, and said that the left leg was fully as strong as the right, but when exposed to cold he was more sensible ot its effects upon that leg. About two months after the operation he had a violent pain in the upper part ofthe left foot, similar to what is felt when a nerve is pressed: this lasted for about six weeks, and afterwards went entirely off. As no nerve was included in the ligature, this affection probably arose from the nerve in its passage through the consolidated parts being deprived of its natural freedom. There was a small tumour, the remains of the aneurismal sac, very distinctly to be felt in the ham, but without pulsation, and to the feel perfectly solid. The following case was operated upon by Mr. Lynn, surgeon of the Westminster Hospital, in the same manner as above mentioned; and the account of the operation is given in his own words :— " Samuel Smart, a hackney-coachman, twenty-five years of age, had a popliteal aneurism, for which I performed the operation in the following manner. I made an incision down to the femoral artery, a little below the middle of the thigh, and having separated the artery from the contiguous parts, I passed under it, by means of an eyed prove, a broad ligature, which was tied so as to cut off all communication with the tumour, and the lips ofthe wound were brought together and retained by sticking-plaster, and the patient put to bed : this leg was rather colder than the other, and ordered to be fomented. The next day he was free from pain, and the limb was warmer than the other. "On the fourth the dressings were removed, and the parts were found united, except at the ligature. ON THE CURE OF THE POPLITEAL ANEURISM. 567 " On the thirteenth the ligature came away, and in the course of the month the whole was healed, and the patient soon afterwards perfectly recovered. William Lynn."

This operation of Mr. Hunter's having succeeded in the first instance, surgeons of different hospitals were led to adopt it, but with some variation, according to their own judgment and the circumstances of the respective cases. These I did not introduce in the order in which they took place; for not being performed exactly in the same manner, they would have interrupted the regular series of those cases above related. But I shall now give them either in the words of the surgeons who performed the operations, or as correctly as I can from having myself been an eye-witness ; and although they were not attended with success, that circumstance will not be found to affect the propriety of the mode of performing this operation which has been recommended above. In a case of aneurism of the femoral artery, the operation was performed by Mr. Birch, surgeon to St. Thomas's Hospital, who relates the history as follows: " John Lewis, a negro, aged forty-three, received a blow on the anterior part of the right thigh ; about a month after he perceived a small tumour, which gradually increased, and his own expression was that he could feel it thump, thump. " As the tumour enlarged, he came to London for advice, applied at St. Thomas's Hospital, on Thursday, the 26th of October, and was directly admitted. On examination I found a large tumour, extending within two inches of Poupart's ligature upwards, and occupying two-thirds of the thigh: a pulsation could be felt, and there was no doubt of the disease being an aneurism of the femoral artery. " I directed seven ounces of blood to be taken from the arm, and an opiate to be given at night; the patient rested well, and the next dav a consultation was held, in which it was proposed to perform an'operation, and endeavour to pass a ligature round the femoral artery, giving the patient the chance of nourishing the limb by the arteria profunda and other anastomising vessels. "On Friday, the 3d of November, it was determined to perform the operation. Mr. Cline undertook to compress the artery as it passes through Poupart's ligament, which he easily effected with a hard compress, in the shape of a T, with a broad bases. « It was agreed, previous to the operation, that an incision should be carried in a semilunar form round the upper part of the aneurismal sac, in order to make room for the longitudinal incision necesary to dissect down to the artery. This was accordingly done, and the integuments raised, so as to make room to feel for the Pulsation of the artery; some portion of cellular membrane and Cpl atic glands were necessarily dissected and removed. With mv Sneers I then separated the muscular fibres, and tore away the Connecting parts till the artery could be plainly felt in pulsation: it 568 HUNTER ON THE BLOOD. was then necessary to divide a part of the fascia covering the artery, which was done by carrying the back of the knife on Mr. Cline's nail, while his finger pressed upon the naked artery; after which the finger and thumb could surround and compress the vessel : an eye-probe, armed with a strong flat ligature, was then pushed through the cellular membrane, and carried under the artery. This being effected, we had such command of the vessel as to be able to strip it down, and pass another ligature somewhat lower. This last ligature was then tied, the first being left loose, to secure us against accident. " The threads being separated and secured, the wound was lightly dressed, the tumour left in its natural situation, and the patient put to bed, with the loss of only four or five ounces of blood during the operation. No pulsation could be perceived in the tumour after the ligature was tied. " On Saturday, November 4th, he had slept well, was easy, and there was sufficient warmth in the extremity to assure me of some circulation. On the 5th, the discharge from the wounded lymphatics was so abundant as to make it necessary to remove the superficial dressings ; the tumour was rather softer to the touch, and the skin about the apex of it began to shrivel. " The discharge of lymph continued till the 9th, and then the wound began to digest; affording however, a very small quantity of pus. The tumour grew thinner at one point, and seemed as if disposed to ulcerate the integuments. This day I passed a bleedingligature round the leg, just below the knee, and the veins tumefied sufficiently to have bled freely if they had been punctured. " 10th. He was feverish in the evening. " 11th. He had stools from some laxatives I had directed and was better. " 12th. The tumour was very thin at one part, and a fluctuation evidently to be felt. The limb was warm and moveable, but the patient was feverish, and delirious at night. A decoction of bark, with a sedative bolus, was directed for him; but he would not take them. "13th. The wound looked florid, and afforded good pus; the patient was feverish and delirious; the tumour was threatening to burst. This day he took his medicines. " 14th. He became sensible, but was languid and hot; the tumour burst, and discharged serum and grumous blood ; he fainted ; the dressings were not disturbed, he slept composedly; fainted again about six o'clock in the evening, and expired. I saw him at seven, when the limb was still warm; I removed the dressings, and found a small stream of fresh arterial blood, which had issued [from the wound. " It appears probable that if the patient had applied for relief before the tumour was so much enlarged, the operation might have succeeded, as we should then have been able to have tied the sound artery so much lower down. J. Birch." ON THE CURE OF THE POPLITEAL ANEURISM. 569 The body was examined the morning after the patient's death by Mr. Cline. " The integuments on the middle of the tumour were mortified. The blood contained in the tumour was very putrid, and the greater part of it fluid, it appearing to have been dissolved by putrefaction. " Water injected by the external iliac artery escaped freely from the wound at the ligature where the artery was open, which appeared to have ulcerated at that part. " In laying open the artery from the ligature to the heart, its internal surface appeared of a bright red. This appearance lessened at the curvature of the aorta, yet it was very evident in its semilunar valves. " The arteria profunda, which passed off from the femoral artery, rather less than half an inch above the ligature, was also inflamed within. There were near two inches of the femoral artery between the ligature and the aneurismal sac, the internal surface of which was of the usual white colour; from this a membranous-like substance could be peeled off, that seemed to resemble coagulable lymph. " The opening where the artery passed out ofthe aneurismal sac was near three inches below the part where it entered. In opening this part of the artery from the sac to the ham it appeared quite sound, and of its natural colour. H. Cline."

This mode of operating was adopted by Mr. Pott in a case of popliteal aneurism in St. Bartholomew's Hospital, which operation having been the object of medical attention for some time, I shall give a brief account of it, as I was present at the time it was performed. Mr. Pott began the operation by making an incision about five inches in length upon the posterior part of the thigh, through the common integuments, a little higher than the tumour, and in the direction ofthe thigh, between the two hamstrings; he then dissected down to the vessels at the upper end of the incision, which, being there deep seated, proved both tedious and difficult Having come to the vessels, a double ligature was passed, and the two portions tied separately, at nearly half an inch distance. The depth of the incisioS made it difficult for any but the operator and hose immediately assisting him to see what was included in he ligature and atthetimetheVphteal artery was supposed to be secured by it. The wound was dressed up in the common way. The second day after the operation a puisation^was fe in the tumour, which afterwards enlarged so much that Mr. Pott ampu-

^^ifsaiKat the aneurism appeared, upon an examination of the limb, to have been in an anastomising branch, not in the trunk of

^ThrSliowing remarks upon this operation will tend in some 570 HUNTER ON THE BLOOD. measure to illustrate the method recommended and practised by Mr. Hunter. The mode of taking up the artery in the ham must be always unfavourable to the future success ofthe operation, if either the artery itself should be diseased, or if the tumour, by being so contiguous to the violence done in the operation, should be effected by the consequent inflammation, which seems to have been the case in Mr. Pott's operation, as I understand two abscesses were formed close to the sides ofthe sac. Had the aneurism been situated in an anastomosing branch ofthe popliteal artery, given off below the ligature, there should have been no pulsation afterwards in the tumour; and were it in a branch going off above the ligature, the pulsation in the tumour should have continued immediately after the operation, and should have been increased by it, neither of which effects appear really to have taken place, which throws a doubt upon the situation of the aneurism if the popliteal artery was rendered impervious by the compression of the ligature. Mr. Cline, surgeon to St. Thomas's Hospital, performed the operation for the popliteal aneurism in the following manner, at which I was present; and although not exactly as recommended by Mr. Hunter, it was very nearly so. The particulars of the case I have not received from Mr. Cline, but have taken them from my own observation, and the information of gentlemen who attended the patient, and were present at the examination after death. The patient was a sailor, who came into St. Thomas's Hospital to undergo the operation for the popliteal aneurism. Mr. Cline made a longitudinal incision on the anterior part ofthe thigh, and having laid bare the artery, passed, by means of a tin instrument, a double tape, about one inch broad, behind the artery, the two pieces of tape lying one over the other ; the piece of tin which conducted the tape was cut off, and a cork nearly an inch long was laid upon ihe artery, and confined to its situation by means ofthe upper tape, producing in this way a sufficient pressure upon the vessel included between the ligature and cork to stop the circulation, and consequently the pulsation in the tumour in the ham ; the other portion of tape was left loose. The intention of securing the artery in this way was to compress the sides of the vessel together, and produce an union without ulceration. The patient went on very well, and the ninth day the tapes were removed, and everything seemed to be going on very favourably, when the patient was attacked by a fever (which was supposed to be caught from another patient in the same ward), of which he died. Upon examining the state of the limb after death, it was found that ulceration had taken place through the whole extent of the artery included in the tape, and sinuses were formed both upwards and downwards, in the course ofthe thigh, to some distance. I cannot conclude this paper without observing that it is seldom ON THE CURE OF THE POPLITEAL ANEURISM. 571 in giving an account of a new operation we are able to collect materials sufficient to render it so satisfactory as the present, having in our possession not only the successful and unsuccessful cases, but also an account of the appearances after death, under both circumstances, so that the causes of failure are rendered evident in those instances in which it did not succeed, and the means that are likely to insure future success are clearly pointed out. The operation is in itself simple ; it requires but a short time in the performance, and produces little, if any, affection of the constitution ; but its advantages are more clearly seen by contrasting it with the common mode of operating for the popliteal aneurism. This is by exposing the sac in the ham through its whole extent, laying it open, scooping out the blood, searching for the two orifices leading into it, and taking up the artery with a ligature both above and below the sac. When this operation is over there remains a large deep-seated sore, composed of parts not perfectly in a natural state, and in a most disadvantageous situation, which sore is to suppurate, granulate, and heal, a process that is not soon performed, and which must leave a stiff knee for some time afterwards. Yet this is considering the operation in the most favourable view, since there is always a risk, from the artery being diseased so close to the sac, of the patient dying from a secondary bleeding ; and when that does not happen there is still some danger of not being able to support the constitution during the healing of so large a sore, under circumstances so very unfavourable. It is in comparison with this operation, the only one before in use, that the present improvement is to be considered, and it is in this view that I have thought it deserving the attention of the Society. I cannot close this account without inserting the following case, in addition to those already stated, in favour of this operation. I have received it just time enough to give it a place, as the paper was in the press before it came to hand, and feel myself obliged to Mr. Earle for his readiness in communicating it. Hanover-Square, March 10, 1792. " Sir « At vour request I send you some account of the following case, and am" Your most obedient servant, "James Earle. « John Smith, about fifty years of age, was received into St. Bartholomew's Hospital on account of a fever. After having been under the care of the physician some time he complained of a swelling and pain in his left leg, for which I was desired to visit hi He said, about six months before he had fallen from a scaffold • that his leg was caught between the rounds of a ladder, which broke his fall? that he felt immediately pain in the upper part ofhtale"; ?oon afte; it began to swell and had gradually increased ?o ts present size. On examination there appeared a large hard swelling under the heads of the gastrocnemn muscles, reaching up 572 HUNTER ON THE BLOOD. to the bend of the leg. A pulsation was plainly to be felt in it, and there was no doubt of its being an aneurism. It was now increasing very fast in size ; the tumour, by its pressure, caused exquisite pain, all the lower part of the leg was loaded with oedematous swelling, and it became absolutely necessary to perform some operation to prevent a mortification taking place. " Having noticed with much satisfaction the success which attended Mr. Hunter's method of tying the artery in the thigh, in a similar case, I decided in favour of that operation ; but as, in the present instance, the artery appeared to be in its natural and perfect state in the ham, and in its whole course, till it reached the dilatation below the knee, I preferred taking it up in that part, rather than to tie in the middle of the thigh, under the sartorius muscle, though it lies there more superficial, and more easily to be got at; because I thought the chance of the circulation being carried on was equal, if not greater, and if it should fail, and symptoms should occur to create a suspicion of an impending mortification, there might be an opportunity of removing the limb above the ligature, which would be impracticable if the artery was tied in the middle of the thigh. "Jan. 28, 1792. The patient being laid on his face, and the tourniquet loosely applied, I made an incision about five inches long, in the direction of the artery, within those tendons which compose the inner ham-string. I then gradually separated the cellular substance; in doing this the nerve was exposed, which ran in its usual course, external to the artery, and much more superficial. In finding the artery some difficulty occurred, on account of the tumefaction of all the parts, affected by their vicinity to the aneurism, and from the imperceptibility of pulsation in the artery till it was actually laid bare: however, having discovered it in its usual situation near the bone, and in its natural undilated state, I passed a ligature round it, about two inches above the tumour. I now again examined, and being convinced that the artery was included alone in the ligature, I gradually made it tight, till I felt a pulsation above it, and none below, when I desisted, concluding that any pressure beyond this degree would be useless and dangerous. " I will just observe here, that I found the common aneurismal needle with a handle very inconvenient, and would recommend in this case, where the artery lies so deep, a blunt semicircular needle, with the eye about half an inch from the end, without any handle. " The wound was closed in the usual manner, and the edge brought together by sutures. On the following day the man was free from pain, the tumour much less tense or hard, and the whole leg greatly unloaded. No perceptible alteration in the heat of the limb could be remarked ; when the current of blood was obstructed in the superficial veins by pressure, on its removal they immediately again became turgid, and in short every appearance indicated a continuance of perfect circulation. " On the fifteenth day succeeding the operation the ligature came ON THE CURE OF THE POPLITEAL ANEURISM. 573 away, the limb was soft and unloaded, and the incision nearly healed ; at the distance of six weeks there remains a small tumour, with some perceptible fluctuation. The patient cannot perfectly extend his leg, but is able to walk with the assistance of crutches." ADDITIONAL CASES TO ILLUSTRATE MR. HUNTER'S METHOD OF PERFORMING THE OPERATION FOR THE CURE OF THE POPLITEAL ANEURISM. BY SIR EVERARD HOME, BART., F.R.S. Read June 5, 1798. [From the Transactions of a Society for the Improvement of Medical and Chirurgical Knowledge, Vol. II., p. 235. 1800.] In a former paper published in the first volume of the Transactions of this Society, I stated the reasons that induced the late Mr. Hunter to propose this operation, and mentioned all the cases in which it had at that time been performed, either by himself or others. .... Since Mr. Hunter's death two cases have occurred in which the patients had aneurisms in both popliteal arteries, and others where the disease was only in one. In these cases this operation was performed, and the intention of the present paper is to communicate to the Society these new facts. Case I. John Clegg, aged 33 years, a tobacco-pipe maker, was admitted into St. George's Hospital May 29th, 1797, with two popliteal aneurisms. . . It appeared that about eight weeks before his admission, while walking, he felt, for the first time, an acute pain in the calf of the right leg, extending downwards, which gradually increased. Ihree weeks afterwards he perceived a swelling in the ham, which enlarged, and in a week more had an evident pulsation in it: this swelling proved to be an aneurism of the popliteal artery. The knee also swelled, and was painful. When he came into the hospital the aneurismal tumour in the right ham appeared externally through the skin, of the size of a large hen's egg: there was also at that time a small aneurism in the popliteal artery of the other leg. He had thick lips, a very red nose ana a pale complexion ; and for some months past had experienced frequent bleedings from

thTheSnature of his business obliged him to walk, upon an average, 16 or 17 miles a day, carrying pipes to his respective customers, \l\tL arpater part of whom he was compelled to drink porter, ^ ic lnSthe -u?seof°the day, did not amount to less than 8 or 10 pints. There seemed to have been no other particularity in his mode of life. 4Q 574 HUNTER ON THE BLOOD. After he had remained in the hospital a few days, on June 9th I performed the operation of taking up the femoral artery on his right thigh. In doing this I laid bare the fascia which covers the vessels, and made an opening through it large enough to expose the whole diameter of the artery. I passed a crooked silver needle, with a rounded point, behind it, taking care not to include the vein and nerve; in this way the needle and ligature were readily brought out on the other side. The ligature was tied, and immediately the pulsation in the tumour ceased. The wound was united by slips of adhesive plaster and a bandage. About two hours after the operation he complained of considerable pain in the sac, and in the course of the femoral artery, even to the toes. He took thirty drops of tincture of opium, which dose was repeated at bed-time. June 10th. His skin was hot, and his pulse above 100 in a minute; ten ounces of blood were drawn from the arm, and he was ordered to take the saline mixture: the blood, on standing, showed no buff. Two hours afterwards his pulse was 96 in a minute, and softer ; he complained of numbness in the leg, with a tingling sensation in about the middle of the sole of the foot; the heat was the same as in the other leg. 11th. His pulse was 120 in a minute, and strong; there was little moisture on the skin, and great pain in the leg and foot. 13th. The wound was dressed for the first time since the operation ; it had a healthy appearance, and the parts were united by the first intention ; the tumour in the ham was somewhat diminished, while that in the other leg rather increased since the operation. 16th. He was perceptibly better ; the pain in the limb was much abated : the ligature was removed. This was the 12th day from the operation. 27th. The wound was nearly cicatrized, and the aneurism in the other ham was increasing very fast; he was therefore removed from the hospital for a fortnight to reestablish his health, that he might undergo the second operation with greater security. July 11th. He returned to have the operation performed on the other femoral artery ; which at his desire was done on the same day of the week as the former operation, and exactly five weeks after it. 14th. The operation was conducted in every respect in the same manner as the preceding; and the pulsation in the tumour ceased as soon as the ligature was tied upon the artery. 15th. His pulse was 100 in a minute, and full: he passed a restless night, and complained of great pain in the limb, and a slight pulsation was felt in the aneurismal sac. 16th. The pulsation in the sac was more distinct ; this I imagined arose from some collateral branch having a communication with the sac. A compression was made upon the tumour by means of a circular bandage, to prevent the influx from any collateral branch. ON THE CURE OF THE POPLITEAL ANEURISM. 575 17th. His pulse was about 96 in a minute, strong and full; he had little sleep during the night; the pulsation in the sac was rather less than the day before. He complained of pain about the wound, but not so much in the foot as after the first operation. 18th. His pulse was 73 in a minute : the pulsation in the sac was less ; he had a very good night, but now complained of considerable pain in both feet. 24th. He had a slight hemorrhage from the wound, which was brought on by his mind being agitated in consequence of some improper treatment his wife had received : it stopped of itself, but the tourniquet was loosely applied in case of a return. He complained of heat where the ligature was made; there was no difference in the pulsation of the sac. 26th. A second hemorrhage took place from the wound, to the amount of three or four ounces, and then stopped. His pulse was about 108 in a minute; he complained of being faint and languid. I removed the dressings, and upon endeavouring to bring away the ligature, some blood escaped from the wound, per saltum, of a florid colour, supposed to be from the rupture of a small artery; a compress was immediately applied to the part, which stopped the bleeding. I removed the compress from the ham, the pulsation in the sac being much abated ; eight ounces of blood were drawn from the arm, and he took the saline mixture. The hemorrhage returned about seven in the evening, but was immediately stopped by increasing the compression. 27th. He was very restless all night, and had acute shooting pains in the wound ; the bandages were slackened. 28th. He slept well during the night, and had a greater degree of moisture on the skin, and the pains in the limb were not so violent ; the dressings were removed, and the wound appeared disposed to slough ; the pulsation in the sac was scarcely perceptible. 29th? His spirits were much better; there was an appearance of swelling and inflammation between the wound and the knee; the pressure was therefore removed from the artery, and applied more uniformly over the whole limb. 30th. The ligature was removed without hemorrhage ; this was the sixteenth day after the operation. August 6th. The hemorrhage returned at five o clock in the morning, to the amount of four ounces ; a compress was applied to the wound, and kept on by a bandage; he was very restless during

1 8thSHis pulse was 110 in a minute, and felt hard and contracted. He was ordered to take a bolus, containing three grains of camphor everv six hours. 10th Had a bleeding from his nose, amounting to two ounces; he was ordered to lose four ounces of blood from the arm ; the dose of camphor was increased to five grains; the pulse was 108 in a minute and quick before the bleeding, but about twenty minutes afterwards the pulse was reduced to 96 in a minute, and he complained of faintness. 576 HUNTER ON THE BLOOD. 14th. The tourniquet was totally removed. 16th. He felt great pain upon touching the skin of any part of the limb, but particularly at the ham. 18th. Had a very good night, and the wound was superficial, and reduced to the size of a sixpence: it was now exactly five weeks from the operation; a circular bandage was still applied, and the sore dressed with ungt. hydrarg. nitrat. and hog's lard in equal proportions; there still remained great sensibility in the skin. 26th. The pain in the limb was much abated; the leg had been fomented with tepid salt water for several days, which gave him a great deal of ease ; the wound was nearly healed, and the limb admitted of motion without uneasiness. September 18th. He was quite well. The pulsation being felt in the aneurismal sac the evening after the femoral artery was tied, its continuance for several days, and then ceasing altogether, are circumstances so curious, that it may be right to give some explanation of them. The only way in which the pulsation could recur in the tumour, after it had been stopped, must be by means of anastomosing branches ; and if the branch which renewed the communication had its origin near the ligature, it is probable that in the progress of the cure the femoral artery became obliterated higher up than the origin of this branch, and shut it up. The extent ofthe artery rendered impervious above the ligature, in the first case operated upon by Mr. Hunter, in which there was an opportunity of examining the parts after death, makes this more probable. A case of aneurism of both popliteal arteries occurred to Mr. Joseph Harris, surgeon, at Whitehaven, in the year 1796, of which he has favoured me with the following account, as an addition to the facts in favour of Mr. Hunter's mode of operating in cases of this disease. Case II. William Spencer, a corporal in the Cumberland militia, in the thirty-second year of his age, of a tall and muscular make, was admitted a patient into the Whitehaven Hospital in June, 1795. He had a firm inelastic swelling, extending from the middle of the left thigh down to the toes, and attended with most excruciating pain. He gave the following account of his case. Fifteen months ago he wore for two months together a pair of tight leather breeches, which made his legs swell, and become so painful that he was obliged to leave them off; after which time the swelling in the leg subsided, and he suffered no further inconvenience. About a month after this, on his return from a journey on foot of ten miles, on a very hot day, he felt uneasiness in the hams of both legs, but went to bed in good health. In the course of the night he had a very profuse sweat, and the next day he discovered a small swelling in each ham; that on the left side continued gradually to increase, and had a pulsation in it, which was sensible to the touch for many months, but afterwards was not to be distinguished; the swelling diffused itself over the limb till it arrived at its present size. ON THE CURE OF THE POPLITEAL ANEURISM. 577 Upon examining the other ham, I found an aneurismal tumour about the size of a nutmeg, which he said had remained stationary from the time of its first appearance. The left leg seemed to be too much diseased to give the smallest hopes of saving it; the limb was therefore amputated. Upon examining the parts in the amputated limb, the aneurismal sac in the ham was found to have been burst, and eleven pounds and a half of coagulated blood had been diffused among the muscles, which were in a state approaching to mortification. The stump healed kindly, and he continued well for three months, without any apparent enlargement of the aneurism in the right ham ; but at the end of this time it began to increase in size, and one day, after a violent exertion on his crutches, he had considerable pain in it, with an evident increase of the swelling, which now stretched both the ham-strings; there was also a diffused swelling extending over the joint of the knee. From the history of the aneurism in the other leg, there was reason to expect that this was now burst, and would go on in exactly the same way; it was therefore determined to perform the operation for the aneurism immediately according to Mr. Hunter's method : this was done on the 15th of November, 1795. The artery alone was included in a single ligature, and the skin with the other parts brought together, and retained by adhesive plaster. For about two hours after he was put to bed he complained of coldness in the foot, but on covering it with flannel it felt as warm as the leg, which was of the natural heat ofthe body. On the second day the swelling of the leg was a good deal abated, and the tumour itself softer. On the third day the swelling of the leg was entirely gone, and the tumour more diminished. On the sixth day the dressings were removed, and the wound had healed by the first intention, except an inch at the lower part, where the ligature passed out. There had been no pain, or swelling of the parts, since the operation, and the limb continued of the nalural temperature, except on the fourth day, when it was two degrees hotter by Fahrenheit's thermometer. On the eleventh day the ligature came away, attended with a considerable discharge of matter; this continued on the twelfth: I therefore made compression on the sides of the wound throughout its whole length, by compresses and a tight roller. On the fifteenth the discharge scarcely moistened the dressings. He was attacked with a purging, attended with disorder of the whole system and loss of appetite, which lasted for a fortnight. Durino- this time the superficial sore remained stationary ; but it was completely healed, and the patient discharged from the hospital at the end of the fifth week. The two following cases contain nothing remarkable; but as they were both operated on in exactly the same manner as the first case in the present paper they increase the number of instances in which the most simple mode of performing this opera- 49* 578 HUNTER ON THE BLOOD. tion has been attended with success. I have therefore thought that they will appear to the Society of sufficient importance to be inserted in this place. Case III. A. B., a dragoon, near six feet high, about thirty-six years of age, came into St. George's Hospital in the year 1794, on account of a popliteal aneurism, for which I performed the operation. In making the external incision I was desirous of keeping it in a line with the edge ofthe sartorius muscle, that the muscle and skin might not form a double valve, and prevent the ready discharge of any matter that should be formed, which I had found to be the case in some instances above mentioned. As soon as the artery was exposed I did not attempt to disengage it laterally, but made a small opening on each side of it, just large enough to admit the end ofthe instrument, conveying the ligature, which was in this way passed round the artery, the nerve and vein being pushed on one side ; the ligature was secured, and the wound brought together by means of adhesive plaster. The man had no fever; little, if any, inflammation came upon the limb; the ligature came away the twelfth day; and in three weeks he went to his own house, there being only a superficial sore on the skin, which in a week more was entirely healed. Case IV. George Pile, thirty-five years of age, butler to His Royal Highness the Duke of Clarence, a stout man, of a sallow complexion, and a hard drinker, had been sensible of the feeling of weakness in his left leg for two or three months, when he perceived a tumour of the size of a pigeon's egg in the ham: ten weeks after he applied to Mr. Knight. The tumour had been enlarged, after a journey from Margate upon the top of a stage-coach about a fortnight before, so that now he could not button the knee of his breeches; there was a strong and equal pulsation in every part of the tumour, which left no doubt of its being aneurismal ; the leg was swelled and felt hard, the pulse was quick, and at times intermitted; his general health, however, was tolerably good. Mr. Knight proposed performing the operation according to Mr. Hunter's method ; and, knowing that I had lately performed it in that way with success, requested that I would assist him. The operation was performed on the 29th of September, 1797, by Mr. Knight, nearly in the same way that I have described in the case last related : the silver needle was passed behind the artery, without including the vein or nerve, or detaching it for more than a quarter of an inch from its lateral connections; the pulsation in the ham ceased the moment the ligature upon the artery was tied. The cut edges of the wound were brought together, except where the ligature passed out. On the 30th, the pulse was full and quick ; he was therefore ordered to lose ten ounces of blood. August 3d, the dressings were for the first time removed, and the wound was found united by the first intention : a small quantity of matter was pressed out by the side of the ligature. The wound was now dressed every day, and on the 18th he was allowed to get up; the ligature was ON THE CURE OF THE POPLITEAL ANEURISM. 579 examined at each dressing, but could not be brought away without using more force than it was prudent to employ. On the 22d, there was a slight hemorrhage from the wound, which was readily stopped by compression. On the 30th, the ligature came away with great ease. November 11th, the wound was completely healed; the tumour in the ham was nearly gone ; the patient in perfect health, and daily gaining strength, and the use of his limb. Case V. Mr. Marshal, a gentleman about fifty years of age, consulted me, in May, 1798, on account of a popliteal aneurism. The tumour in the ham, at the time I saw it, was considerably larger than a hen's egg. After examining the case, I gave it as my opinion that an operation was absolutely necessary to prevent a fatal termination of the disease ; and that the chance of recovery depended wholly on the state of the femoral artery: if that was healthy, the operation which I intended to perform would succeed ; and if it was not, even amputation of the limb would fail, as the divided artery could not be made to unite. Dr. Marshal's opinion was taken whether it was advisable to try compression upon the aneurismal tumour; this he did not approve of, and the patient determined to submit to the operation. He walked about, and drank a pint of wine daily, till the operation was performed ; although I had urged him in the strongest manner to remain perfectly quiet in a horizontal posture, and to live sparingly. • The operation was performed on the 22d of May ; I was assisted by Dr. Marshal, and Dr. Wallis was present. When the incision through the skin had exposed the sartorius muscle, it appeared unusually large, and the fascia covering the artery was got at with difficulty, and was indistinctly seen : this I attributed to the state of the muscles, induced by the exercise which the patient had continued to use. r ^ i r U Jl My first attempt to secure the artery failed, from the needle passing over it, and only including a portion of the fascia. I therefore exposed the artery more completely, about an inch higher up the thigh, and surrounded it by a ligature: the pulsation in the tumour immediately ceased, and the wound was dressed*as in the former cases. The leg continued colder than the other for two days, and then regained its usual heat. On the fourth day, the dressings were removed, and the wound had a healthy appearance; at this time there was a pulsation in the

tU 0°nUthe seventh day, he bore being moved to have his bed made, and was considered to be going on perfectly well From some mistaken notion he now indulged himself in the use of wine, without my knowledge. . _ ... On the ninth day, he had a violent shivering fit, which was not mentioned to me; and the use of wine was, notwithstanding,

^Orfthe tenth day, the discharge from the wound was much increased, and the thigh and leg were swelled. 580 HUNTER ON THE BLOOD. On the eleventh day, there was a slight bleeding from the wound, and in the evening a similar bleeding also took place. Alarmed at this circumstance, I left an assistant with the patient. The tourniquet likewise, which had remained on the thigh, was now adjusted, in case it should be necessary to use it. On the twelfth day, at four in the morning, a violent hemorrhage came on, and at nine he died. The limb was examined next day, in the presence of Dr. Marshal, Dr. Wallis, and Mr. Colthurst. The ligature was found to have included the artery without the vein, and when the artery was laid open the space embraced by the ligature was quite white, and the coats at that part so thin as to be almost transparent; and there were also several small ulcerations through the coat by which the blood had escaped; there was not the smallest union of the sides ofthe artery; but immediately above and below the ligature the inner membrane had an unusual red appearance. The inner membrane had lost its usual polish, and had its surface covered with opaque white spots; the same appearance in a less degree was seen in the artery near the groin. The aneurismal tumour proved to be a diseased dilatation of the popliteal artery, of an oval form, situated between the heads of the gastrocnemius muscle. In this case the femoral artery was so much diseased that probably neither amputation nor any other operation with which we are acquainted would have been attended with success. But as that is a circumstance which rarely happens, and can never be ascertained during the person's life, it ought not to be considered as an objection to the operation, though its possible existence must always render the event somewhat uncertain. The internal surface ofthe artery in the present case became inflamed, without admitting the union of its sides, as happens when the operation succeeds. This inflammation, although probably owing chiefly to the diseased state of the artery, may yet in part have been produced by the neglect of proper attention in regard to diet and rest previous to the operation, and more particularly by the indulgence in wine after it. A CASE OF PARALYSIS OF THE MUSCLES OF DEGLU- TITION, CURED BY AN ARTIFICIAL MODE OF CON- VEYING FOOD AND MEDICINES INTO THE STOMACH Read September 21,1790. [From the Transactions of a Society for the Improvement of Medical and Chirurgical Knowledge, Vol. I., p. \QZ. 1793.] Diseases which are not mortal in themselves may often, from their secondary effects, become the cause of death; but if these secondary effects are removed, the disease frequently admits of a cure, or CASE OF PARALYSIS OF THE MUSCLES OF DEGLUTITION. 581 even ceases of itself. Thus diseases, when they attack the vital organs, may, from the nature of the parts alone, prove fatal; and this will be sooner or later, according to the particular functions of the parts diseased. Obstructions to breathing, to the passing of the urine, to the act of swallowing, or the discharge of the faeces, with all terminate in death, if continued for a certain length of time, whatever be the nature of the disease. Difficulty in swallowing, the subject of the present paper, may arise from a variety of causes, since an obstruction in any part of the canal leading from the mouth to the stomach will produce that complaint. The swallowing our food is a complicated operation, and includes two different actions. The first of these conveys it into the oesophagus; the second carries it along that canal into the stomach ; and the parts which perform these two actions are in themselves distinct, so that one may be obstructed or diseased while the other remains perfectly sound. The first action is often impeded, or wholly prevented, by inflammation ; but this is seldom of long continuance, and the cure is probably promoted by the patient's being obliged to abstain from food. It is also impeded by swellings in the neighbouring glands, but this will commonly be in a less degree; and where it threatens suffocation, or a total prevention of deglutition, the patient can often be relieved by an operation. The second action is sometimes obstructed by ulcers in the oesophagus, which have a cancerous appearance; sometimes strictures in that canal, which are of a permanent nature ; also spasmodic contractions, which are commonly confounded with strictures, but may, I believe, be readily distinguished both from strictures and ulcerations. Ulcers and strictures, from being permanent diseases, in the end destroy the patient; but spasmodic contractions admit of being cured. I have known a case of this kind get well in a fortnight from the use of electricity, which had not been at all relieved by mercury, although the mouth was affected by it for a month. There is another cause of difficulty in swallowing, which is the reverse of contraction, viz., paralysis. Whether the muscular coats of the oesophagus are ever affected by it I cannot determine -but the muscles of the pharynx have become paralytic, and the patient has died of hunger. c . nnt nc As this disease is only rendered dangerous from the want of a substitute for deglutition, it becomes our duty to adopt some Lt fiekl mode of conveying food into the stomach, by which the patien may be kept alive while the disease continues, and such medicines may be administered as are thought conducive to the

CTsuccessful instance of this practice is given in the following Gate of well-marked paralysis in the muscles of the pharynx ; the relation of which is given by the patient. 582 HUNTER ON THE BLOOD. John S -1, about fifty years of age, became hypochondriac, and attacked by what are called nervous disorders in consequence of anxiety of mind, brought on by various distresses. In the beginning of his complaints he felt something crack within his head, and from that period his sensations became very acute, his passions, sympathies, and aversions exceedingly strong. December 28, 1786, while under the influence of an uncommon degree of hypochondriasis, about one o'clock in the morning, he brought up a glutinous substance from his stomach, like the white of an egg, which seemed to relieve him, but did not remove an aversion which he had taken to his relations, his children, and even to life itself, of which he was tired. He afterwards continued affected with low spirits and pains in the head, became restless, and turned his mind to religious subjects ; as these affections either increased or diminshed, he had frequent and severe fits of crying. About the 21st of February, 1790, he had a violent cold in his head, with a considerable running from the nose; and on the 7th of March, between one or two in the morning, awoke with a sense of choking, and felt soon after a numbness in the whole of his right side, together with a paralysis of the muscles of deglutition, which deprived him of the power of swallowing. By the advise of a physician he was cupped, blistered round the throat, and electrified ; he was, in the meantime, supported by nourishing clysters. March the 9th, finding no benefit from this plan, he waited upon Mr. Hunter, with a letter from Mr. Cumming, watchmaker, accompanied by Mr. Duncan the surgeon. Mr. Hunter, considering the support of the patient, and some mode of administering medicine, to be the first object, proposed that a hollow flexible tube should be passed down into the stomach, through which he might receive nourishment and medicines; and mentioned his having an instrument of that kind, made of spiral wire, covered with gut for the purpose of injecting liquids into the stomachs of animals, which might be applied to the present case; but that Mr. Cumming was better able to assist them in getting a tube that would answer that purpose. He also recommended, when the tube was made, to inject jellies, eggs beat up with a little water, sugar, and milk, or wine by way of food, and that the medicines might be mixed with it. In compliance with these directions they contrived a tube, and injected into the stomach some of the above-mentioned substances twice a-day ; three drams of valerian were mixed with this food, increasing the dose to six drams. Laudanum was given in the dose of forty drops by clyster, and afterwards thirty drops by the mouth ; but both doses affected the head, without procuring rest. The valerian was continued till the 26th of March, at which time he had taken four ounces, and had evidently recovered a degree of sensation in his throat. Mr. Hunter was again consulted, and ordered two scruples of flour of mustard, and one dram of tincture of ON LOOSE CARTILAGES IN JOINTS. 583 valerian, twice a-day : under this treatment the power of swallowing gradually returned, and on the 29th the use of the tube was no longer necessary. The natural sensation of the throat and right arm had not returned in the month of April. The instrument made use of was a fresh eel-skin, of rather a small size, drawn over a probang, and tied up at the end where it covered the sponge, and tied again close to the sponge where it is fastened to the whalebone, and a small longitudinal slit was made into it just above this upper ligature. To the other end of the eel-skin was fixed a bladder and wooden pipe similar to what is used in giving a clyster, only the pipe large enough to let the end of the probang pass into the bladder without filling up the passage. The probang, thus covered, was introduced into the stomach, and the food and medicines were put into the bladder, and squeezed down through the eel-skin. The instrument did not produce irritation in the fauces or oesophagus: in such cases, the parts, losing their natural sensibility, allow greater liberties to be taken with them. An eel-skin seems very well adapted for this purpose, being smooth, pliable, and readily passed into the stomach : but as cases of this kind may occur where eels cannot be procured, a portion of the gut of any small animal, as a cat or lamb, will make a very good substitute. SOME OBSERVATIONS ON THE LOOSE CARTILAGES FOUND IN JOINTS, AND MOST COMMONLY MET WITH IN THAT OF THE KNEE.

BY SIR EVERARD HOME, BART., FROM MATERIALS FURNISHED BY MR. HUNTER.

[From the Transactions of a Society for the Improvement of Medical and Chirurgical Knowledge, Vol. I., p. 229. 1793.]

Such detached and moveable cartilages as are the subject of the following observations, are not peculiar to the joint of the knee; they occasionally occur in other joints of the body ; but as they are most frequently met with in the knee, and it is in that joint they produce symptoms which render them the object of a chirurgical operation, I shall consider them more particularly when situated in that cavity. These "substances in their structure are analogous to bone, but in their external appearance bear a greater resemblance to cartilage; they are not, however, always exactly ofthe same structure, beino- in some instances softer than in others. Their external surfaced smooth and polished, which, being lubricated by the synovia, allows them to be moved readily from one part of the joint to 584 HUNTER ON THE BLOOD. another, seldom remaining long at rest, while the limb is in motion : when they happen to be in such situations as to be pressed upon with force by the different parts of the joint, they occasion considerable pain, and materially interfere with its necessary motions. The circumstance of their being loose, and having no remains of a visible attachment, made it difficult to form conjectures respecting their formation ; and I believe that no satisfactory account of their origin had been given, till Mr. Hunter's observations threw light upon the subject. The circumstances which led him to the investigation of this subject, appear at first sight so foreign to the purpose, that they require some explanation. In the course of his experiments and observations, instituted with a view to establish a living principle in the blood, Mr. Hunter was naturally induced to attend to the phsenomena which took place when that fluid was extravasated, whether in consequence of accidental violence, or other circumstances. The first change which took place he found to be coagulation; and the coagulum thus formed, if in contact with living parts, did not produce an irritation similar to extraneous matter, nor was it absorbed and taken back into the constitution, but in many instances preserved its living principle, and became vascular, receiving branches from the neighbouring blood-vessels for its support; it afterwards underwent changes, rendering it similar to the parts to which it was attached, and which supplied it with nourishment. In attending to cases of this kind, he found that where a coagulum adhered to a surface, which varied its position, adapting it to the motions of some other part, the attachment was necessarily diminished by the friction, rendering it in some instances pendulous, and in others breaking it off entirely. To illustrate this by an example, I shall mention an instance which occurred in the examination of a dead body. The cavity of the abdomen was opened, to examine the state of its contents, and there appeared lying upon the peritoneum a small portion of red blood, recently coagulated; 1 his, upon examination, was found connected to the surface upon which it had been deposited, by an attachment half an inch long, and this neck had been formed before the coagulum had lost its red colour. This steeped in water, so as to become white, appeared like a pendulous tumour. From this case it became easy to explain the mode in which those pendulous bodies are formed, that sometimes occur attached to the inside of circumscribed cavities; and the principle being established, it became equally easy for Mr. Hunter to apply it under other circumstances, since it is evident, from a known law in the animal ceconomy, that extravasated blood, when rendered an organized part ofthe body, can assume the nature ofthe parts into which it is effused; and consequently the same coagulum which in the abdomen formed a soft tumour, when situated on a bone, or in the neighbourhood of bone, forms more commonly a hard one. The cartilages found in the knee-joint, therefore, appeared to him ON LOOSE CARTILAGES IN JOINTS. 585 to originate from a deposit of coagulated blood upon the end of one ofthe bones, which had acquired the nature of cartilage, and had afterwards been separated. This opinion was further confirmed by the examination of joints which had been violently strained, or otherwise injured, where the patients had died at different periods after the accident. In some of these there were small projecting parts, preternaturally formed, as hard as cartilage, and so situated as to be readily knocked off by any sudden or violent motion of the joint. This opinion Mr. Hunter has mentioned for many years in his lectures, and his arguments in favour of it are so consonant to the general laws by which the operations of an animal machine are regulated, as scarcely to require further evidence: but the following case exhibits so many facts in confirmation of this theory, that it appears to me to afford a full explanation of the process above mentioned, and completely to establish the opinion. A man, sixty-eight years of age, was brought into St. George's Hospital, on the 20th of March, 1791, with a simple fracture of the right thigh-bone. The fracture was situated about three inches below the great trochanter; it was treated in the usual manner, but no bony union had taken place in the beginning of June, about eleven weeks after the accident, the portions of the bone at that time being readily moved on each other. There being nothing in the man's general health to account for this backwardness in the parts to unite, he was desired to explain whatever circumstances he was acquainted with respecting himself, likely to throw any light upon it. This inquiry led the patient to mention, that his right os humeri had been broken three years and nine months before, but that the bones had continued disunited, and admitted of motion more freely at that time than immediately after the accident. Rest having proved ineffectual in producing union in the thigh, and it being evident, from the circumstance of the arm, that there was a natural backwardness in the constitution to form bony union, he was directed to walk upon crutches, and to press as much upon the broken thigh as the state of the parts would admit, without considerable pain, with a view to rouse the parts to action, forcing them by a species of necessity to strengthen the limb. In the course of a fortnight there was an evident firmness in the bone, and in less than two months the patient could walk with the assistance of a stick. As there was something uncommon in the case, he was allowed to remain in the hospital to acquire strength ; in this convalescent state he was seized with a complaint in his bowels, which was very violent and carried him off. After death the thigh-bone was found firmly repaired by bony union but the bone of the arm, an account of which is more immediately to the present subject, admitted of motion in every direction at the fractured part. The arm was carefully dissected, to examine the state of the fractured parts, between which there was no callus, but a large bag 50 586 HUNTER ON THE BLOOD. filled with a glairy fluid, resembling synovia. (See Plate IV. fig. 3.) The internal surface of this bag was smooth, like a capsular ligament, and its attachment to the bones was ofthe same kind: it adhered firmly to the surrounding parts, which were thickened and consolidated, rendering it very strong. The two ends of the bone were adapted to each other, all the irregularities having been absorbed ; and their surfaces were of considerable extent, from the fracture being oblique ; the upper one was slightly concave, or rather had two depressions, with a middle ridge ; the lower one was smaller and rounded, and was adapted to both concavities, which received it in the different motions ofthe parts. The surfaces of the bones fitted for motion were not completely covered with cartilage, but studded over with it, and the bone was exposed in the interstices ; a number of projecting parts, covered with cartilage, grew out from the surfaces, some exceedingly small, others large. From the edges of the bones and the capsular ligaments these excrescences were larger, extremely irregular in their shape, broader in their attachments, softer in their texture, and serrated upon the external edge. Thirty or forty small substances, similar to these above mentioned, were found loose in the cavity, varying in size from that of millet-seed to that of a barley-corn, of a roundish form, and smooth on the surface ; the largest of them were more flattened and serrated. Their hardness varied considerably, some of them being as soft as cartilage, others so solid as not to be pierced by a needle. Those bodies must have been originally attached, and broken off by the friction ofthe parts on one another. The preternatural cavity which I have described was in its nature and use similar to the naturally formed joints of the body ; these excrescences and loose bodies were its principal peculiarities, the formation of which appears to have been the result of the violence committed on the parts previously to the formation of the joint, and may be explained in the following manner. When the bone was broken the ruptured vessels poured out their contents into the interstices of the lacerated parts, for the purpose of uniting them again; this, however, not taking place, it was necessary to accommodate the parts to their disunited state ; to this end the blood, which had now become useless, was in part absorbed, and the new joint formed. The remains of the coagulated blood, which had not given the stimulus for its own absorption, underwent changes in its nature, assimilating it as much as possible to that of the surfaces to which it was attached, in some parts its texture resembling ligament, in others being more allied to cartilage or bone. When we compare these substances with the loose cartilages found in the knee-joint, which are also produced in consequence of accidental violence, and similar in their appearance, we are naturally led to conclude that the latter originate from extravasations of blood, altered in its nature by the parts in which it is deposited, ON LOOSE CARTILAGES IN JOINTS. 587 similar to those in the artificial joint above described. In both cases they are evidently new-formed substances, and the readiest mode by which we can account for their production is to refer them thus to the blood, from which fluid every part of the body was originally formed. These loose cartilages, as they have been commonly called, although they may occur in any joint of the body, are found most frequently in the knee; and in this joint, from the pain and inconveniences they produce, have become the object of an operation in surgery. One or more of them may be formed in the same joint; I have known one instance in which there were three ; they are commonly about the size of a horse-bean, often much smaller, and sometimes considerably larger; when very large they do not give so much trouble to the patient as the smaller kind. A soldier in the 56th regiment has one nearly as big as the patella, which occasions little uneasiness, being too large to insinuate itself into the moving parts of the joint. In this disease the removal of the loose bodies is the only mode of relief, and it is fortunate for those who are afflicted with it that the knee-joint is the most favourable in the body for such an operation; for the cavity extends a considerable way beyond the moving parts of the joint, and is continued into parts, which, when divided, will more readily unite than the common capsular ligaments, and be less liable to communicate the inflammation that comes upon the wound to the general cavity. As these loose bodies cannot always be found, no time can be fixed for the operation ; but the patient, who will soon become familiar with his own complaint, must arrest them when in a favourable situation, and retain them there till the surgeon can be sent for. Before the operation the limb should be extended upon a table in an horizontal position, and secured by means of assistants; the loose cartilages are to be pushed into the upper part of the joint above the patella, and then to one side; the inner side is to be preferred, as in that situation only the vastus internus muscle will be divided in the operation. Should there be several of these bodies they must be all secured, or the operation should be postponed till some more favourable opportunity, since the leaving of one will subject the patient to the repetition of an operation not only painful, but attended with some degree of danger. The loose bodies are to be secured in the situation above mentioned, by an assistant, a task not easily performed while they are cut upon, from their being lubricated by the synovia ; and if allowed to escape into the general cavity, they may not readily, if at all, be brought back into the same situation. The operation consists in making an incision upon the loose cartilase which it will be best to do in the direction ofthe thigh, as the wound will more readily be healed by the first intention. If the 588 HUNTER ON THE BLOOD. skin is drawn to one side previously to making the incision, the wound through the parts underneath will not correspond with that made in the skin, which circumstance will favour their union. The incision upon the cartilage must be made with caution, as it will with difficulty be retained in its situation if much force is applied. The assistant is to endeavour to push the loose body through the opening, which must be made sufficiently large for that purpose ; but as this cannot always be done, the broad end of an eyed probe may be passed under it, so as to lift it out; or a sharp-pointed instrument may be stuck into it, which will fix it to its situation, and bring it more within the management ofthe surgeon. The cartilages being all extracted, the cut edges of the wound are to be brought together, and, by means of a compress of lint, not only pressed close to one another, but also to the parts underneath, in which situation they are to be retained by sticking-plaster and the uniting bandage. As union by the first intention is of the utmost consequence after this operation to prevent an inflammation upon the joint, the patient should remain in bed with the leg extended till the wound is perfectly united, or at least all chance of inflammation at an end. OBSERVATIONS ON CERTAIN HORNY EXCRESCENCES OF THE HUMAN BODY.

BY SIR EVERARD HOME, BART., FROM MATERIALS FURNISHED BY MR. HUNTER.

Read February 17, 1791. [From the Philosophical Transactions, Vol. LXXXI., p. 95.]

The history of diseases belongs not properly to the province of the naturalist or philosopher ; it is intimately connected with the inquiries of the physician and anatomist; but when disease becomes a cause of the formation of parts similar to others existing in nature, but rendered uncommon by novelty of situation, or produced in animals to which they are not naturally appropriated, it may be considered as having instituted a monstrous variety, highly deserving of attention from the naturalist. To describe such varieties is indeed more fully the office of natural history than of medicine; but the investigation of diseases which are found to subvert the ordinary laws of nature respecting the situation or production of parts in an animal body, undoubtedly belongs to the medical practitioner. By these considerations I have been induced to lay before the Royal Society the following account of a disease which occurs ON HORNY EXCRESCENCES OF THE HUMAN BODY. 589 sometimes in the human body, very remarkable in its effects, but very little understood as to its cause, namely, the production of an excrescence similar to a horn. So curious a phenomenon has naturally attracted the attention of the ignorant as well as the philosopher ; and the individuals who have had the misfortune to be subject to this disease have been considered as monsters. Horny excrescences arising from the human head have not only occurred in this country, but have been met with in several other parts of Europe; and the horns themselves have been deposited as valuable curiosities in the first collections in Europe. In giving the history of a disease so rare in its occurrence, and in its effects so remarkable as almost to exceed belief, it might be thought right to take some pains in bringing proofs to ascertain that such a disease does really exist; I consider the doing so as less necessary at present, there being two women now alive and residing in England, who are affected by the complaint. I shall, however, in the course of this Paper, bring other evidence from the testimony of the most respectable authors who have considered this subject. The following cases contain a very accurate and distinct history ofthe progress ofthe disease through its different stages, and make any further detail of the symptoms entirely unnecessary. Mrs. Lonsdale, a woman, fifty-six years old, a native of Horncastle in Lincolnshire, fourteen years ago observed a moveable tumour on the left side of her head, about two inches above the upper arch of the left ear, which gradually increased in the course of four or five years to the size of a pullet's egg, when it burst, and for a week continued to discharge a thick, gritty fluid. In the centre of the tumour, after the fluid was discharged, she perceived a small, soft substance, ofthe size of a pea, and of a reddish colour on the top, which at that time she took for proud flesh. It gradually increased in length and thickness, and continued pliable for about three months, when it first began to put on a horny appearance. In two years and three months from its first formation, made desperate by the increased violence of the pain, she attempted to tear it from her head, and with much difficulty, and many efforts, at length broke it in the middle and afterwards tore the root from her head, leaving a considerable depression, which still remains in the part where it grew. Its length altogether is about five inches, and its circumference at the two ends about one inch, but in the middle rather less. It is curled like a ram's horn contorted, and in colour much resembling isinglass. From the lower edge of the depression another horn is now growing of the same colour with the former, m length about three hiches and nearly the thickness of a small goose-quill; it is less rnntorted and lies close upon the head. A third horn, situated about the upper part of the lambdoidal suture is much curved, above an inch in length, and more ,n c,rcurnfe rence at its root: its direction is backwards, with some eleva- 590 HUNTER ON THE BLOOD. tion from the head. At this place two or three successive horns have been produced, which she has constantly torn away ; but, as fresh ones have speedily followed, she leaves the present one unmolested, in hopes of its dropping off. Besides these horny excrescences, there are two tumours, each the size of a large cockle; one upon the upper part, the other about the middle of the left side of the head; both of them admit of considerable motion, and seem to contain fluids of unequal consistence, the upper one affording an obscure fluctuation, the other a very evident one. The four horns were all preceded by the same kind of incysted tumours, and the fluid in all of them was gritty ; the openings from which the matter issued were very small, the cysts collapsed and dried up, leaving the substance from which the horn proceeded distinguishable at the bottom. These cysts gave little pain till the horns began to shoot, and then became very distressing, and continued so, with short intervals, till they were removed. This case is drawn up by the surgeon who attended the woman for many years, which gave him frequent opportunities of seeing the disease in its different stages, and acquiring an accurate history of its symptoms. Mrs. Allen, a middle-aged woman, resident in Leicestershire, had an incysted tumour upon her head, immediately under the scalp, very moveable, and evidently containing a fluid. It gave no pain, unless pressed upon, and grew to the size of a small hen's egg. A few years ago it burst, and discharged a fluid : this diminished in quantity, and in a short time a horny excrescence, similar to those above-mentioned, grew out from the orifice, which has continued to increase in size; and in the month of November, 1790, the time I saw it, was about five inches long, and a little more than an inch in circumference at its base. It was a good deal contorted, and the surface very irregular, having a laminated appearance. It moved readily with the scalp, and seemed to give no pain upon motion ; but when much handled the surrounding skin became inflamed. This woman came to London, and exhibited herself as a show for money ; and it is highly probable that so rare an occurrence would have sufficiently excited the public attention to have made it answer her expectations in point of emolument, had not the circumstance been made known to her.neighbours in the country, who were much dissatisfied with the measure, and by their importunity obliged her husband to take her into the country. That the cases which I have related may not be considered as peculiar instances from which no conclusions can be drawn, it may not be amiss to take notice of some of the most remarkable histories of this kind, mentioned by authors, and see how far they agree with those I have stated in the general characters that are sufficiently obvious to strike a common observer; for the vague and indefinite terms in which authors express themselves on this subject show plainly that they did not understand the nature of the disease, and their accounts of it are not very satisfactory to their readers. ON HORNY EXCRESCENCES OF THE HUMAN BODY. 591 In the Ephemerides Academic? Natures Curiosorum there are two cases of horns growing from the human body. One of these instances was a German woman,* who had several swellings, or ganglions, upon different parts of her head, from one of which a horn grew. The other was a nobleman,f who had a small tumour, about the size of a nut, growing upon the parts covering the two last or lowermost vertebra? ofthe back. It continued for ten years without undergoing any apparent change ; but afterwards enlarged in size, and a horny excrescence grew out from it. In the History o"f the Royal Society of MedicineJ there is an account of a woman, ninety-seven years old, who had several tumours on her head, which had been fourteen years in growing to the state they were in at that time ; she had also a horn which had originated from a similar tumour. The horn was very moveable, being attached to the scalp, without any adhesion to the skull. It was sawn off, but grew again; and, although the operation was repeated several times, the horn always returned. Bartholine, in his Epistles,§ takes notice of a woman who had a tumour under the scalp, covering the temporal muscle. This gradually enlarged, and a horn grew from it, which had become twelve inches in the year 1646, the time he saw it. He gives us a representation of it. which bears a very accurate resemblance to that which I have mentioned to have seen in November, 1790. No tumour or swelling is expressed in the figure ; but the horn is comino1 directly out from the surface ofthe skin. ' In the Natural History of Cheshire,|| a woman is mentioned to have lived in the year 1668, who had a tumour or wen upon her head for thirtv-two years, which afterwards enlarged, and two horns grew out of it;" she was then seventy-two years old. There is a hornv excrescence in the British Museum, which is eleven inches long, and two inches and a half in circumference at the base, or thickest part. The following account of this horn I have been favoured w th by Dr. Gray, taken from the records of he Museum A woman, named French, who lived near Tenterden had a umm r or wen upon her head, which increased to the size of a walnu and in the forty-eighth year of her age this horn began tVgrow, and in four years arrived at its present size.11

* Ephem. Acad Nat Cor Dec.iii An V Append, j. 148.

in;;^^"«s:'ihe "eck of awoman in l"at neigl,b0M- 'T.V G=re.ory said that one of seven inches long, and of a dark brown coloor,

^Sllf.^"^ "^""^ "' 0* from awonaan's head in Cheshire.'1 592 HUNTER ON THE BLOOD. There are many similar histories of these horny excrescences in the authors I have quoted, and in several others; but those mentioned above are the most accurate and particular with respect to their growth; and in all of them we find the origin was from a tumour, as in the two cases I have related ; and, although the nature ofthe tumour is not particularly mentioned, there can be no doubt of its being ofthe incysted kind, since in its progress it exactly resembled them, remaining stationary for a long time, and then coming forwards to the skin ; and the horn being much smaller than the tumour previously to the formation of the horn is a proof that the tumour must have burst and discharged its contents. From the foregoing account it must appear evident that these horny excrescences are not to be ranked among the appearances called lusus naturce; nor are they altogether the product of disease, although undoubtedly the consequence of a local disease having previously existed. They are, more properly speaking, the result of certain operations in the part for its own restoration; but the actions ofthe animal ceconomy being unable to bring them back to their original state, this species of excrescence is formed as a substitute'for the natural cuticular covering. To explain the manner in which those horns are formed it will be necessary to consider the nature of incysted tumours a little more fully; and in doing so we shall find that this particular species does not differ in its principle, nor materially in its effects, from many others which are not uncommonly met with in the human body, as well as in those of many other animals, which, as they are more frequent in their occurrence, are also much better understood. Incysted tumours differ exceedingly among themselves, both in the nature of their contents, and in their progress towards the external surface of the body. Many of them have no reference to our present purpose; it is only the more indolent kind to which I mean now to advert: some of these, when examined, are not found to contain a fluid, but a small quantity of thick, curd-like matter, mixed with cuticle broken down into small parts; and upon exposing the internal surface of the cyst, it is found to have a uniform cuticular covering adhering to it, similar to that of the cutis on the surface ofthe body, from which it only differs in being thinner, and more delicate, bearing a greater resemblance to that which covers the lips. Others of this kind, instead of having cuticle for their contents, are filled with hair mixed with a curdled substance, or hair without any admixture whatever, and have a similar kind of hair growing upon their internal surface, which is likewise covered with a cuticle. These cuticular incysted tumoars were, I believe, first accurately examined by Mr. Hunter, to whom we are likewise indebted for an explanation ofthe mode in which the parts acquire this particular structure. Mr. Hunter considers the internal surface of the cyst to be so circumstanced respecting the body, as to lose the stimulus of being ON HORNY EXCRESCENCES OF THE HUMAN BODY. 593 an internal part, and receive the same impression from its contents, either from their nature, or the length of application, as the surface ofthe skin does from its external situation. It therefore takes on actions suited to such stimuli, undergoes a change in its structure, and acquires a disposition similar to the cutis, and is consequently possessed of the power of producing cuticle and hair. What the mode of action is, by which this change is brought about, is not easily determined ; but from the indolence of these complaints it most probably requires a considerable length of time to produce it. That the lining of the cyst really does possess powers similar to cutis, is proved by the following circumstances : that it has a power of forming a succession of cuticles like the common skin; and what is thrown off in this way is found in the cavity of the cyst. It has a similar power respecting hair, and sometimes the cavity is filled with it, so great a quantity has been shed by the internal surface. Besides these circumstances, the hair found in the cyst corresponds in appearance with that which grows upon the body of the animal; and when incysted tumours of this kind form in sheep, they contain wool. What is still more curious, when such cysts are laid open, the internal surface undergoes no change from exposure, the cut edges cicatrize, and the bottom of the bag remains ever after an external surface. Different specimens, illustrative of the abovementioned circumstances, are preserved in Mr. Hunter's collection

The cysts that produce horny excrescences (which are only another modification of cuticle) are very improperly considered as giving rise to horns; for if we examine the mode in which this substance grows, we shall find it the same with the human nails, coming directly out from the surface of the cutis. It differs from the nails in not being set upon the skin by a thin edge, but by a surface of some breadth, with a hollow in the middle exactly in the same manner as the horn ofthe rhinoceros ;* atleast this is.evidently the case in the specimen preserved in the British Museum, and in one which grew out from the tip of a sheep's ear; they are also solid, or nearly so, in their substance. This n ode of growth is very different from that of horns, which are a 1 formed upon a core, either of bone or soft parts, by wh ch means they have'a cavity in them ; a structure pecuhar to this kind

^y^t—ln different animals T^PP-^*X observations, to be.confined in.^^^^X^h stance proper to the animal '" ™cn J „ /oductions „f animal cuticle, hatr, nail ^/£t^*dX.u£« from each other substance, only differing in trivi instance of an incysted

the external appearance. 594 HUNTER ON THE BLOOD. nails of the human body; to which last the horny excrescences, the subject of the present Paper, are certainly very closely allied, both in growth, structure and external appearance; and when of some length, they are found to be so brittle as to break in two, upon being roughly handled, which could not happen either to hoof or horn. In the sheep they produce wool instead of hair; and in one instance in that animal, where they gave rise to horny excrescence, it was less compact in its texture, and less brittle than similar appearances in the human subject; upon being divided longitudinally, the cut surface had more the appearance of hoof, and was more varied in its colour than nail. Incysted tumours being capable of producing horns, upon the principle we have laid down, is contrary to the usual operations of nature ; for horns are not a production from the cutis, and, although not always formed upon a bony core, but frequently upon a soft pulp, that substance differs from common cutis in its appearance, and extends a considerable way into the horn ; it is probable that this pulp requires a particular process for its formation.* I shall conclude this paper by observing, that the cases of horns, as they are commonly termed, upon the human head, are no more than cuticular productions arising from a cyst, which in its nature is a variety of those tumours described by Mr. Hunter under the general name of cuticular incysted tumours.y These incysted tumours, when considered as varieties ofthe same disease, form a very complete and beautiful series of the different modes by which the powers of the animal ceconomy produce a substitute for the common cuticle upon parts which have been so much affected by disease as to be unable to restore themselves to a natural state.

* A sheep, about four years old, had a large horn, three feet long, growing upon its flank. It had no connection with bone, and appeared to be only attached to the external skin. It dropped off in consequence of its weight having produced ulceration in the soft parts to which it adhered. Upon examining it there was a fleshy substance, seven inches long, of a fibrous texture, filling up its cavity upon which the horn had been formed. f The principle upon which the production of these excrescences depends being once explained, the modes of preventing their formation, and removing them when formed, will be readily understood, the destruction of the cyst being all that is required for that purpose. This may be done before the tumour open9 externally, or even after the excrescence has begun to shoot out, and will be better effected by dissection than escharotics, since the success of the operation depends upon the whole ofthe bag being removed. ANALYTICAL CONTENTS. INTRODUCTION.

1 Of Diseased Actions, as being incompatible with each other.—2. Of Parts 'susceptible of particular Diseases.—3. Of Sympathy.—4. Of Mortification ........... PAGE "

CHAP. I.—GENERAL PRINCIPLES OF THE BLOOD. 1 Of the mass of Blood, as composed of different Parts.-2. Of Coagulation and iteFffecTs!-3. Ofthe SeruniU. Ofthe red Globules.-5. Of the Quantity $ Blood"and Course of its Circulation,-* Of the Living Principle of the . Blood.—7. Some unconnected Experiments respecting the Blood . iy

CHAP. II.--OF THE VASCULAR SYSTEM. 1 Opnpral Observations on Muscular Contraction and Elasticity.—2. General L SSSmtiSSTthe0 Elongation of Relaxed Mu.de.-* Of ttetoucgjeof Arteries —4 Of the Vasa Arteriarum.—5. Ofthe Heart.—6. General Ubser v^o s on Blood-Vessels.-7. Valves of Arteries.-8. Of the Division or Branching of Arteries.-9. Of the Action ofthe Arteries, and the Velocity of the Blood's Motion.—10. Of Veins.......

CHAP. L__UNION BY THE FIRST INTENTION. 1 Of Iniuries in which there is no External Communication.-^. Of Injuries

attended with Death in a superficial Part .

CHAP II—FUNDAMENTAL PRINCIPLES OF INFLAMMATION.

,. Ofthe different Causes whiehincrease a„c, din^h ^u^tibflitjilor Inflammation, either in the wholBodyor in Parte.. £ im _|. of Weakness of Constitution and of Farts wnue »" Inflammations to be Parts of *?*%'S£.%?2S?5f1& h OrdeTs of Inflammation respecttreated of—4. Ofthe two Parstnal^ f h Adhcsive Inflammation [fJjSU^n^l^^ *ges-7. Of the different Degrees and "different Kinds of Inflammation ..••••

CHAP. IIL—THE ADHESIVE INFLAMMATION. ■ t a „t;^r, 9 Of the Colour, Swelling, and Pain 1. Action ofthe Vessels in .^^^n In&mmation.'-^ Of fhe Producof Inflamed Parts.-3. The Heat otPirts:n ^ Adhesive Inflammation tion of Cold in Inflammation.-^ ^tine is j fect in its commences after its Cause and in ^^fnlnflammation.-T. The State of Consequences.-6 Of the Uniting^JJem^ The Effects 0finflammaUon the Blood and of *\^nloton™£° m of girml on the Constitution according to the di _g_ General Reflections on the Structures, and whether Vital or ^ Methods of Resolution by constitu- Resolution of Inflammatu>m i ^ ineg internaily and of local Applications tional means.-ll. Ihe use 0bservations on Repulsion, Sympathy, Denvain Inflammation.—W-^ener different Forms in which Sedition, Revulsion, and Translation. 596 ANALYTICAL CONTENTS. cines are applied, and the Subsiding of Inflammation.—14. Of the Use ofthe Adhesive Inflammation........page 307

CHAP. IV.--OF THE SUPPURATIVE INFLAMMATION. 1. The Symptoms ofthe Suppurative Inflammation.—2. Ofthe Treatment necessary in Inflammation when Suppuration must take place.—3. The Treatment ofthe Inflammation when Suppuration has taken place.—4. Collections of'Matter without Inflammation.—5. Of the Effects such Formations of Matter have on the Constitution.—6. The Effects of the Suppurative Inflammation on the Constitution...........382

CHAP. V.—of fus. 1. Of the General Opinion of the Formation of Pus.—2. Of the Properties of Pus.—3. Of the Use of Pus........ 415

CHAP. VI.--THE ULCERATIVE INFLAMMATION. 1. Of the remote Cause of the Absorption of the Animal itself.—2. Of the Disposition of living Parts to absorb and be absorbed.—3. Of Interstitial Absorption.—4. Of the Progressive Absorption.—5. Of Absorption attended with Suppuration, which I have called Ulceration.—6. Of the Relaxing Process.— 7. Of the Intention of Absorption of the Body in Disease.—8. The Modes of Promoting Absorption.—9. Illustrations of Ulceration . . . 433

1. Of Granulations independent of Suppuration.—2. The Nature and Properties of Granulations.—3. Longevity of Granulations.—4. Of the Contraction of Granulations . .........459

CHAP. VIII.--OF SKINNING. 1. The Nature of the new Cutis.—2. Of the new Cuticle.—3. Of the Rete Mucosum...........470

CHAP. IX.--EFFECTS OF INFLAMMATION, AND ITS CONSEQUENCES ON THE CONSTITUTION. 1. Of the Hectic.—2. Treatment of the Hectic.—3. Of Dissolution . 474

PART III. THE TREATMENT OF ABSCESSES. 1. The Progress of Abs«esses to the Skin.—2. Of the Time when Abscesses should be opened.—3. Ofthe Methods of opening Abscesses, and treating them afterwards...........485

CHAP. I.—OF GUNSHOT WOUNDS.

1. The Difference between Gunshot Wounds and common Wounds .—2. Of the different Effects arising from the Difference in the Velocity of the Ball.—3. Of the different Kinds of Gunshot Wounds......509

CHAP. II.—OF THE TREATMENT OF GUNSHOT WOUNDS.

1. Of the Propriety of dilating Gunshot Wounds.—2. Of the strange Course of some Balls.—3. Penetrating Wounds of the Abdomen.—4. Of penetrating Wounds in the Chest.—5. Of Concussions and Fractures of the Skull.—6. Of Wounds compounded with Fractured Bones, or containing extraneous Bodies. —7. Of the Time proper for removing Incurable Parts.—8. Of the Treatment of the Constitution..........515 PLATES TO HUNTER ON THE BLOOD, INFLAMMATION, AND GUNSHOT WOUNDS. 51 EXPLANATION OF THE PLATES. PLATE. I.

In this plate is represented the embryo of the chick in the incubated egg, at three different stages of its formation, beginning with the earliest visible appearance of distinct organizations. The preparations from which these figures are taken form part of a complete series, contained in Mr. Hunter's collection of comparative anatomy. They are meant to illustrate two positions laid down in this work, viz. That the blood is formed before the vessels, and, when coagulated, the vessels appear to arise ; that when new vessels are produced in a part, they are not always elongations from the original ones, but vessels newly formed, which afterwards open a communication with the original. Fig. 1. In this figure the only parts that are distinctly formed are two bloodvessels; on each side of these is a row of small dots or specks of coagulated blood, which are afterwards to become blood-vessels. Fig. 2. The formation of the embryo is further advanced, vessels appear to be rising up spontaneously in different parts of the membrane ; and the specks, out of which they are produced, are in many parts very evident. Fig. 3. The number of blood-vessels is very considerably increased; they now form a regular system of vessels, composed of larger trunks, and a vast number of ramifications going off from them.*

* These figures were selected by Mr. Hunter for their present purpose, from an extensive series of drawings ofthe embryo of the goose at different stages of development, and of which he left only a general account in manuscript, but no detailed descriptions. The above explanations of the figures were doubtless added by the Editor of the original Edition of the ' Treatise on the Blood ;'—that they are not from the pen of Mr. Hunter, is evident from the fact of there being upwards of ten figures in the original series, showing as many stages of the development of the embryo, earlier than that represented in Fig. 1, but with a visible and distinct organization. After a comparison of these figures with the embryo of the fowl and emeu at corresponding stages of development, I would propose the following explanation of them. At the period represented in Fig. 1, red blood is not formed, but although " the heart is beating, it then contains a transparent fluid before any red globules are formed," as Mr. Hunter has justly observed, (See p. 71). The colourless fluid which circulates at this period, when the chick may be compared with the white-blooded invertebrate animals, is not, however, composed entirely, as Mr. Hunter supposed, of the serum and lymph, but contains many colourless globules, smaller than the red blood-discs of the mature bird, and presenting, under a very high magnifying power, a granular structure like the colourless nuclei of the blood-discs. While, however, the embryo thus exhibits an analogy to the white-blooded animals in the nature of its circulating fluid, it expresses at this, and even at an earlier period, the essential characters of the great division of animals to which it belongs. The row of dots, on each side of the two longitudinal white lines, are the primitive cartilages in which the ossification of the vertebrae commences; and the lines themselves are the folds of the serous layer of the germinal membrane, including the rudiments of the spinal chord and brain ; the three divisions of which, viz., medulla oblongata, optic lobes, and cerebral hemispheres, are indicated by the dilatations which succeed each other from behind forwards, towards the anterior or upper end of the embryo. The semicircular white line, surrounding the rudimental head, is the fold of the serous layer of the germinal membrane, forming the 600 HUNTER ON THE BLOOD. PLATE II.

Represents two rabbit's ears, one in the natural state, the other in an inflamed state, in consequence of having been frozen and thawed. The vessels are injected, and as they belonged to the same head, the force applied, and other circumstances, must have been exactly similar. The difference in the size of the vessels, and the difference in the thickness of the ears themselves, are very evident; but there was an opacity in the inflamed ear compared with the other, which it was not possible to express. Fig. 1. The ear in its natural state. AA. The projecting part of the ear. B. That part which is covered by the skin of the head. CCC. The principal arterial trunk. Fig. 2. The inflamed ear. A A. B. CCC. represent the same parts as in fig. 1. D. A hranch rather larger than the trunk, not distinguishable in the natural state of the ear. Fig. 3—8. Represent six squares of a glass micrometer, each side of a square being -gl-g part of an inch. 3, 4, 5, exhibit different appearances ofthe particles of human blood, their central depression, and the various positions in which they may he seen when rolling down an inclined surface. 6, 7, 8, represent the globules of the blood of a skate, which differ from those of human blood principally in being of a much larger size, in their oval outline, and in the oval figure of their central depression. PLATE III.

Fig. 1. A portion of the ilium taken from the intestines of an ass. The intestine was in a state of inflammation, and shows the internal surface of the gut partly covered by a layer of coagulating lymph thrown out by the great degree of inflammation which the parts had undergone. The internal membrane was extremely vascular, and when injected, vessels were seen in portions of the coagulating lymph. AA. The inner surface of the intestine. BB. The coagulating lymph which adhered to it. Fig. 2. The peritoneal coat of a portion of the human intestine, in an inflamed state, to show its vascularity, and to show a small portion of coagulating lymph attached to it by a narrow neck, which is supplied with vessels from it. circumference of the depression in the yolk, into which the head is beginning to sink. This fold afterwards extends downwards over the dorsal aspect of the embryo, and forms the amnios. The concave edge of the fold thus descending, is slightly indicated near the lower dilated part of the embryo at Fig. 3. The projection on the right side of the embryo (which is seen from behind) opposite the second cerebral enlargement, is the punctum saliens. There is little doubt that Mr. Hunter intended this figure to represent the stage at which colourless blood is circulated, as described in the passage above quoted. And it may be observed that this most interesting fact in the history of the development of the vertebrate embryo, has been lately reproduced (by MM. Coste and Lelpech), and generally received as a recent discovery. The 2d figure illustrates the observation, " The globules do not appear to be tormed in those parts of the blood already produced, but rather to raise up in the surrounding parts." The outline of the punctum saliens, or rudimental heart, is rendered conspicuous by the red blood which it now circulates : the red globules are aggregated in different parts of the opake area. In the third.figure the zonular, or terminal sinus is formed, and the circulation of red blood is established in the omphalo-mesentenc vessels, distributed over the yet incomplete vitelline sac. It is obvious from Mr. Hunter's own description, that vessels, and the heart itself, preexist in the embryo to the formation of red globules; and I have myself observed, in the surrounding opake area, at the period corresponding to that represented in Fig. 1, canals already established before the red colouring matter had made its appearance.—R. Oweit. EXPLANATION OF THE PLATES. 601 Fig. 3—6. Diagrams to explain the action of the valves of the aorta. See p. 198. Fig. 3. Shows the artery in its systole, with the three valves nearly close to its sides, aaa. circular section of the aorta, b b the mouths of the coronary arteries, almost covered by, and in the hollow pouch of the valves, d the area within the valves. Fig. 4. Shows the artery in its diastole, when the three valves run nearly into straight lines, making an equilateral triangle of the area of the aorta, aaa the circular section of the aorta in its state of diastole, being now larger about one-fifth, b b the mouths of the coronary arteries, now quite exposed. ccc the hollow pouch of the valves now enlarged, d d d the convexities of the distended valves, filling up the area of artery, e e e the corpora sesamoidea. Fig. 5. Represents the effect of the heart's systole on the aorta and its valves. a a a a section of the artery in a quiescent state, b b b the same in a state of distension. The valves aaa being inextensible retain their original position, while the coats of the artery b b b are distended. The former are prevented from assuming a straight line in consequence of the impulsive force of the arterial current, but the effect of their tension in tucking in the sides ofthe artery is precisely the same. Fig. 6. Represents the periphery of the aorta the moment the systole of the heart ceases, at which the edges of the valves a assume the form of an equilateral triangle. PLATE IV.

Fig. 1 and 2. " Drawings of two aneurisms: one of the crural artery, (No. 136, Jig. 1,) which had cured of itself, shown to me by Mr. Ford of Golden Square ; the other ofthe carotid artery, (No. 136, j%. 2.) shown to me by Dr. Baillie."—Hunterian MS. Fig. 1. Represents an aneurism of the right carotid artery, in which the natural process of obliteration had considerably advanced, a the common carotid. b b the parietes of the aneurismal sac slit open, c a firm old coagulum, completely filling up the cavity ofthe sac and adhering to it. d the internal carotid, e the external carotid. The case occurred in 1787, two years after Mr. Hunter's operation, and is described by Dr. Baillie in the Trans. of a Soc. for the improvement of Med. and Chir. Knowledge, vol. i., p. 119. Fig. 2. Represents an aneurism ofthe right crural artery, the cure of which was completed by the powers of nature. This, Mr. Hunter says, "is the one which had got well, but by what means was not known; or whether it had really been an aneurism or only a contraction of the artery, as I once saw in a young man, a patient in St George's Hospital, and the small dilatation ofthe artery took place after the obliteration of the artery, or whether the aneurismal part had contracted to this size, is not now easily ascertained." a the cardiac extremity of the crural artery, b the contracted sac. c the point of contraction, d the distal extremity of the crural artery. This case (the case of J. Cathy), described by Mr. Ford in the Lond. Med. Journal, vol. ix., p. 144, was seen by Mr. Hunter in September, 1785, three months before he performed his celebrated operation, and is supposed to have been the more immediate cause which suggested it to his mind. Fig. 3. Representation of an artificial joint with loose cartilages in the cavity, a the head ofthe os humeri, b the fractured extremity of the upper portion ofthe bone, c the lower portion of the bone, d d the newly formed capsular lio-ament, surrounding the cavity of the joint, e e the surfaces of the fractured ends of the bone, adapted to each other for the purpose of motion ; the upper surface having two concavities with a middle ridge, the lower one beino- rounded and convex, in some measure fitted to move in either of the cavities. Both these surfaces are partially covered with a substance similar to cartilaoe, in the interstices of which the bone is exposed. 52 602 HUNTER ON THE BLOOD From the surface ofthe bones arise a number of small, hard, projecting parts, very narrow at their base. From the inner surface of the capsular ligament there are excrescences of a softer nature, very large, serrated on their external edge, and attached by narrow necks. Many of these substances, both of the hard and soft kind, were found loose in the cavity, their attachments being broken by the motions of the joint.

Fig. 4. Represents the case of an introsusception. a the ilium passing into the introsusception. b the portion of the ilium included in the introsusception. c the termination ofthe ilium in the valve of the colon, from which a bougie passes into the intestine, d the orifice of the appendix cseci with a bristle introduced into it. e e the course and termination of the appendix cseci. f f f the inverted or contained portion of the colon, the inner surface of which has portions of coagulable lymph adhering to it, the consequence of previous inflammation, g g g the containing colon laid open, to expose the introsusception. Upon its external surface are the appendiculee epiploicae. PLATES HUNTER ON THE BLOOD, INFLAMMATION, ETC. PLATE I. Fig. 1. Fig. 2. Fig. 3. ) PLATES TO HUNTER ON THE BLOOD.

Fig. 2. PLATES TO HUNTER ON THE BLOOD. 609 PLATE III—(Continued.)

Fig. 3. Fig. 4. Fig. 6. PLATES TO HUNTER ON THE BLOOD. 611 PLATE IV. Fig. 1. Fig. 2. Fig. 3. Fig. 4. THE END. NATIONAL LIBRARY OF nlm D2ma2sq t NLM020922549



====================================================================================================
VOLUME IV
Observations on the Animal Oeconomy (notes by Richard Owen, F.R.S.)
====================================================================================================

vpBfWT!" :»»-.t»vsp««fjr: Jfci DUE

THE COMPLETE WORKS t>4 JOHN HUNTER, F.R.S. EDITED BY

SENIOR SURGEON TO THE ST. GEORGE'S AND ST. JAMEs's DISPENSARY, FELLOW OF THE ROTAL MEDICAL AND CHIRURGICAL SOCIETY OF LONDON, ETC., ETC. VOL. IV. OBSERVATIONS ON THE ANIMAL OZCONOMY, ETC., ETC., ETC.;

WITH MOTES BY RICHARD OWEN, F. R. S., PROFESSOR OF ANATOMY AND PHYSIOLOGY, CONSERTATOR OF THE MUSEUM OF THE ROYAL COLLEGE OF ACRJ1£0_H&_IN J;0NDON, ETC., ETC.

■ LIBRARY "'j SURGtOiJ GENERAL'S OFFICE

HASWELL, BARRINGTON, AND HASWELL. NEW YORK: J. & H. G. LANGLEY.

mi v. 4 ' &$l OBSERVATIONS CERTAIN PARTS THE ANIMAL (ECONOMY, INCLUSIVE OF SEVERAL PAPERS FROM THE PHILOSOPHICAL TRANSACTIONS, ETC. JOHN HU NTER, F. R. S. *»

wctn ^otes BY RICHARD OWEN, F.R.S.,

Fellow of the Linnean, Geological, and Zoological Societies of London. Corresponding Member of the Royal Academy of Sciences of Berlin ; of the Royal Academy of Medicine and Philomathic Society of Paris; and of the Academy of Sciences of Philadelphia, Moscow, Erlangen, &c. Professor of Anatomy and Physiology, and Conservator of the Museum of the Royal College of Surgeons in London. $ftf latreljriita:

HASWELL, BARRINGTON, AND HASWELL, 293 MARKET STREET,

NEW ORLEANS: JOHN J. HASWELL & CO.

To the First Edition of the Animal (Economy, 1786. The nine following papers have been read at the Royal Society, and published in the Philosophical Transactions; but in a work of so general a nature, and of which physiological inquiries make so small a part, the few facts and observations which I have given upon such subjects may probably be overlooked by those who are not members of that Society. That they may be more easily procured by students in medicine, and other readers, I have, by an application to the President and Council of the Royal Society, obtained leave to reprint such of them as I consider to be connected with the principles and actions of the Animal CEconomy; and I have added such observations and remarks as have occurred to me since the time they were read before the Royal Society. 2 ADVERTISEMENT

To the Second Edition of the Animal (Economy, 1792. Eleven of the following papers have been read at the Royal Society, and published in the Philosophical Transactions ; but in a work of so general a nature, and of which physiological inquiries make so small a part, the few facts and observations which I have given upon such subjects may, probably, be overlooked by those who are not members of that Society. That they may be more easily procured by students in medicine, and other readers, I have, by an application to the President and Council of the Royal Society, obtained leave to reprint them, in this work, as being connected with the principles and actions of the Animal (Economy; and I have added such observations and remarks as have occurred to me since the time they were read before the Royal Society. PREFACE. Always an admirer of the genius of Hunter, and of late years obliged by official duties to make frequent reference to his numerous and varied productions, especially to those which are scattered through different volumes of the Philosophical Transactions and other works, I have often felt the inconvenience that resulted from the absence of a uniform edition of the whole of the extant works of that great and original thinker. When, therefore, Mr. Palmer first communicated to me his design of publishing a new edition of Hunter's works, I heard with peculiar satisfaction his intention to include in the proposed collection every memoir of the author that could be found in print, and I gladly lent my assistance, which, however, the previous assiduous researches of Mr. Palmer rendered of little moment, towards completing a list of all the published essays or observations on various parts of the ' Animal (Economy' which had not before been included in the work so entitled. The proposal which Mr. Palmer at the same time made to me to edit this portion of the works of Hunter I declined, from a sense of the inadequacy of my powers to grapple with so vast a range of important physiological subjects as the contemplated volume must necessarily embrace, and I sincerely hoped that Mr. Palmer would have found a coadjutor better qualified than myself to do justice to this portion of his most useful and praiseworthy undertaking. After a lapse of nearly two years Mr. Palmer again applied to me to revise the papers on the Animal (Economy, and I then acceded reluctantly to his request, led, by the sole motive of accelerating the appearance of a much wished-for edition, to a task, to which I have since dedicated a great portion of my leisure hours, without the slightest expectation of profit or honour, the experiment having only served to convince me of the difficulty of adding the observations demanded by the progress of science to the text of Hunter in the spirit of its author, and a retrospect of my annotations leading me to suspect that often, with every wish to avoid it, I may have tacitly implied an ignorance on the part of Hunter of factswith which he was probably well acquainted, and to perceive that, in general, the addition of such details tends to overload and destroy the force of the original observations in the text. It is with much more satisfaction that I refer to the additions which have been made to the present edition of the Animal (Economy of the hitherto uncollected or unpublished writings of its original author. 8 HUNTER ON THE ANIMAL OECONOMY. These consist of the following essays. From the Philosophical Transactions: " On the Anatomy of the Siren or Amphibious Bipes (17G6)." "On the Electric Organs of tlie Torpedo (1772)." "On the Electric Organs of the Gymnotus (1755)." " Experiments and Observations on Vegetables with respect to the power of producing Heat (1775)." "A case of Small-pox communicated by the Mother to the Foetus (1780)." " Anatomical Remarks on a New Marine Animal (1785)." "Observations on the Structure and (Economy of Whales (1787)." " On Bees (1792)." " On the Fibrous Structure of the Crystalline Lens (1793)." " On the Fossil Bones of the Caverns of Gailenreuth (1794)." " Six Croonian Lectures read before the Royal Society by Hunter in the years 1776, 1777, 1779, 1780, 1781, and 1782," but withdrawn from publication by the Author. From the Medical Commentaries of Dr. William Hunter: " Experiments on Absorption by Veins." From the Transactions of a Society for the Promotion of Medical and Chirurgical Knowledge, vol. ii. (1794): " Description of the Human Uterus and Ovum in the first Month of Pregnancy." "Observations on the Growth of Bone." There is also added, " An Account of the Anatomy of the Jerboa," contributed by Hunter to the Appendix to Russel's History of Aleppo. And, lastly, " Descriptions of Five Marsupial Quadrupeds," from the Zoological Appendix to White's Voyage to New South Wales. (1790.) In order to bring these different memoirs in juxtaposition with papers on analogous subjects in the original edition of the Animal (Economy, a slight alteration has been made in the arrangement of the different essays composing that work. Those which relate to generation are brought together at the beginning of the volume; then follow the observations on digestion, animal heat, and other physiological subjects; and lastly, the papers of a descriptive character, which refer more immediately to comparative anatomy and zoology. Thus for the first time are collected into one volume the physiological and anatomical stores, from which, in connexion with the materials composing his museum or destined for its illustration, an adequate idea may be formed of the nature of the o-reat work in which Hunter had purposed to record the sum of his'vast experience. In the year 1786, when Hunter published a collection of his detached memoirs in the first edition of the Animal (Economy he PREFACE. 9 observes, with reference to the subject of digestion, " I cannot at present spare sufficient time to give my opinions at large on this subject, with all the experiments and observations I have made upon it, but as soon as I have leisure I shall lay them before the public." And again, in describing the organ of hearing in fishes, he premises that he reserves a more complete investigation of this part of natural history " for a larger work on the structure of animals, which I one day hope to have it in my power to publish," and he states that ever since the year 1760 his researches have been continued in every part of the animal ceconomy. Hence instead of regarding the uncommon structures which he discovered in his dissections of different animals as individual peculiarities, he was enabled to advance beyond the anatomists of his own times, and view them from the same eminence to which subsequent induction has raised the observers of the present day : and referring to the series of preparations in his museum, he boldly states with reference to the structure of the organ of hearing in fish, that it is " only a link in the chain of varieties displayed in the formation of this organ of sense in different animals, descending from the most perfect to the most imperfect in a regular progression." The importance of these views, and the nature and amount of the knowledge which they indicated, could not be appreciated by the contemporaries of Hunter in the absence of a detailed exposition of the evidences on which they were founded. It is no wonder, therefore, that we find his earlier eulogists sometimes founding his claims to scientific eminence on insecure grounds; some, for example, lauding him as the author of a theory of the organizing energy, which may be traced to the time of Aristotle, or as the originator of the doctrine of the vitality of the blood, which is supported with so much eloquence by Harvey and his immediate successors; while others, taking more definite grounds, have often unfortunately selected as his discoveries precisely those subjects of Hunter's special researches in which he had but revived and extended the ideas of his predecessors. Of this we have a striking example in the introductory observations on the character of Hunter contained in Sir Everard Home's Lectures on Comparative Anatomy, vol. i., p. 6, in which the independent function of the vesiculae seminales and the determination of the organ of hearing in fishes are adduced as Hunterian discoveries. The true originators of these and of other ideas and facts which Hunter may have regarded as his discoveries, and which he doubtless did discover so far as independent and original research constitutes a claim to that honour, I have been careful to point out in every case where my reading has led me to detect in an older author a clear anticipation of Hunter. It cannot bo doubted, however, that the ascription to Hunter by his friends and admirers, of facts and opinions to which he had no title as the original discoverer, must have contributed to lower his character in Ihe estimation of continental anatomists; whose 2* 10 HUNTER ON THE ANIMAL CECONpMY. acquaintance with the vast accumulation of facts in comparative anatomy due to the labours of the numerous cultivators of that science in the sixteenth and seventeenth centuries, easily enabled them to detect the weakness of such claims, without perhaps their possessing such a knowledge of Hunter's labours as to justly appreciate their scope and tendency, and to view them, as they deserve to be viewed, in the light of a first great attempt to arrange in one concatenated system the diversified facts in comparative anatomy. Cuvier, for example, in his review of the progress of science in the latter half of the eighteenth century, a period which may be regarded as a second revival of comparative anatomy and physiology, places Hunter in an inferior category of contributors to those sciences. After eulogizing the share which the erudite Haller took in demonstrating the importance of comparative anatomy to the advancement of physiology, and the corresponding effects which the labours of Daubenton and Pallas produced in establishing sounder ideas of the classification of animals, the historian of the natural sciences goes on to state : " John Hunter in England, the two Monros in Scotland, Camper in Holland, and Vicq D'Azyr in France, were the first who followed their footsteps. Camper," he observes, " cast, so to say, a passing glance of the eye of genius on a number of interesting objects, yet almost all his labours were but sketches. Vicq D'Azyr, with more assiduity, was arrested by a premature death in the midst of a brilliant career ; but their works inspired a general interest, which has ever since been on the increase." With reference to the nature or influence of the labours of Hunter, Cuvier is silent; he limits himself to an indication in a marginal note of the Treatise on the Teeth and " les autres ecrits de Hunter inseres en partie dans les Transactions Philosophiques."* This was meting out but scanty justice to the author of the Treatise on the Blood and of the Observations on the Animal (Economy, which abound with so many general propositions in comparative anatomy and physiology. If, however, this opinion of Cuvier be excusable under the circumstances under which it was written, it would be unpardonable not to appeal against it upon the evidence of the higher claims of Hunter afforded by the present edition of his works and by those manuscripts which have already appeared in the catalogue of his Physiological collection published by the Royal College of Surgeons. *Had these manuscripts, explanatory of the design of the Hunterian collection, been published before Cuvier wrote the work from which we have just quoted, that astonishing result of Hunter's labours might perhaps have claimed a passing notice from one whose statements all Europe now receives and all posterity will regard with confidence and respect. " Les autres ecrits," the " other writings" of Hunter to which Cuvier alludes, are indeed devoted rather to the development of

* Histoire des Progres des Sciences Naturelles, depuis 1789, torn, i., p. 302 PREFACE. 11 general principles in physiology than to the detail of the anatomical observations upon which he founded them. Many of the facts ascertained in the course of his higher and more comprehensive inquiries, and incidentally alluded to in the narration, are however fully as interesting and important as those which other anatomists have sometimes thought worthy of being made the subjects of express monographs. But Hunter had higher aims than the reputation of a mere collector of facts in comparative anatomy; and this he not only felt but had expressed in an early period of his career. In a manuscript, copied by Mr. Clift, relating to a dissection of a turtle, he says, " The late Sir John Pringle, knowing of this dissection, often desired me to collect all my dissections of this animal, and send them to the Royal Society ; but the publishing of a description of a single animal, more especially a common one, has never been my wish." Howsoever we ma}' regret this feeling, which has undoubtedly deprived the world of the results of much inestimable labour, and has operated in various ways disadvantageous^ to Hunter's own reputation, yet it indicates the expanded views of the man who entertained it. Had Hunter published seriatim his notes of the structures of the animals which he dissected, these contributions to comparative anatomy would not only have vied with the labours of Daubenton as recorded in the Histoire JVaturelle of Buffon, or with the Comparative Dissections of Vicq d'Azyr which are inserted in the early volumes of the Encyclopedic Methodique and in the MSmoires de VAcadbmie Royale de France, but they would have exceeded them both together. It would be tedious to enumerate, name by name, the different species of animals whose organization was investigated and recorded by Hunter. Mr. Clift has evidence* that he left written descriptions, from autopsy, of the anatomy of the following Mammalia: Species. OfQuadrumana 21 Carnivora . 51 Rodentia 20 Edentata 5 Ruminantia . 15 Pachydermata 10 Cetacea 6 Marsupiata . 10 Of Birds . 84 Reptiles 25 Fishes 19 Of Insects. 29 Species. Species. Of other invertebrate animals, as mollusca, red-blooded worms, and radiata, upwards of twenty. From the titles of manuscripts} * See " Evidence before the Medical Committee of the House of Commons." 12 HUNTER ON THE ANIMAL CECONOMY. therefore, it appears that Hunter possessed, at the period of his decease, original records of the dissections of three hundred and fifteen different species of animals. In addition to these, Hunter's preparations testify that he had dissected twenty-three species of mammalia, sixteen species of birds, fourteen species of reptiles, forty species of fishes, forty-two different mollusca, and about sixty species of articulate and radiate animals; all species of animals of whose anatomy we have no evidence that he left written descriptions. So that by adding these undescribed dissections to those of which we derive the evidence from the list of the manuscripts, and of which described dissections his anatomical collection in like manner contains evidences in the dissected and preserved organs, there is proof that Hunter anatomized at least five hundred different species of animals, exclusive of repeated dissections of different individuals of the same species, besides the dissections of plants to a considerable amount. With respect to the rarer and less known invertebrate animals, Hunter was not content with merely recording their structure and displaying its leading peculiarities in preparations ; but he caused most elaborate and accurate drawings to be made from the recent dissections ; for which purpose he retained in his family many years an accomplished draughtsman, Mr. William Bell, better known as the author of two papers in the Philosophical Transactions, descriptive of the Sumatran Rhinoceros and the Ecan Bonna (Platax arthriticus, Cuv.). Several examples of these beautiful designs have already been published by the Council of the Royal College of Surgeons in the illustrated catalogue of the Hunterian Museum : they relate to the anatomy of the Sepia and Solen, of the Ascidia and Salpa; they illustrate the circulation of the blood in the Crustacea and Anellida; and the figure which Mr. Hunter has given of the circulation in the Chloeia capillata, a red-blooded worm, far surpasses in beauty and detail any of those with which Cuvier illustrates the memoir* dedicated to what he regarded to his latest breath as one of his most interesting discoveries. Hunter had also minutely investigated the anatomy of the cirripeds ;f but of his dissections of these, as of many other animals, it is to be lamented that the preparations and drawings are now the sole evidences. The illustrations of the anatomy of the Echinodermata, both of the spiny species and of the unarmed Holothuria, have never been surpassed either as to minuteness or accuracy; and, excepting the disputed article of the nervous system, little is added in the elaborate and well-known monograph of Tiedemann, to the anatomy of the Holothuria as it is displayed by Hunter.J Now the anatomical labours of Daubenton were confined to that class of animals whose structure most nearly resembles man; he

* Bulletin de la Soc. Philomath., 1791, p. 146. + See Physiological Catalogue of the Hunterian Collection, vol. i., p. 255 pi. IV. t Ibid., p. 251, pi. III. PREFACE. 13 describes the position and length and breadth and number of parts with most praiseworthy zoological precision, but never appears to raise his thoughts to the relations of the structures he detected with the habits of the species, or their adaptation to function. Hence he has been said to have made more discoveries of which he was unconscious than any other cultivator of comparative anatomy. Vicq d'Azyr, on the contrary, adorns his descriptions with many beautiful and philosophical views, but he did not carry his scalpel beyond the vertebrate series ; while Hunter explored every modification of animal structure, from man down to the polype. If Hunter surpassed his contemporaries in the value and amount of the materials which he collected in comparative anatomy, he rises far above them in the application of his facts. By a profound and unremitting meditation on the diversities of structure presented to his view, he derived more accurate notions than were current amongst his contemporaries of the parts essential to the performance of the different functions, and every idea or doubt thus suggested he tested by the most varied, ingenious, and accurate experiments. "Many things," he observes, " arise out of investigation which were not at first conceived ; and even misfortunes in experiments have brought things to our knowledge that were not, and probably could not have been, previously conceived. On the other hand, I have often devised experiments by the fireside or in my carriage, and have also conceived the result; but when I tried the experiment the result was different, or I found the experiment could not be attended with all the circumstances that were suggested."* Few physiologists indeed, if any, have made more numerous, various and conclusive experiments than Hunter. Yet he says, " I think it ma^ ue set down as an axiom that experiments should not be often repeated which merely tend to establish a principle already known and admitted, but that the next step should be the application of that principle to useful purposes."f By this series of labours of mind and hand, prosecuted uninterruptedly from year to year, Hunter at length came to establish a body of physiological doctrines, to the happy influence of which on the treatment of the various " ills that flesh is heir to," every cultivator of the healing science now bears grateful testimony. Most of the enlightened physiologists of this country have acknowledged the high merit and beneficial influence of Hunter's labours; but the general terms in which his merits have been expressed have not availed in raising him from the secondary category of contributors to comparative anatomy, in which he has been classed by Cuvier, and from which some continental writers have lately been disposed to degrade him.J

* Animal GEconomy, p. 417 (the pages throughout refer to the present edition). t Ibid., p. 117. ± See the Esquisse Historique sur PJnaiomie Comparee, prefixed to the French translation of the second edition of Carus's Comparative Anatomy, vol. i., p. xxx. 14 HUNTER ON THE ANIMAL CECONOMY. The present seems, therefore, to be a fitting opportunity to attempt to define the grounds for assigning a higher station to Hunter, considered as a physiologist and comparative anatomist. In this endeavour, however, to prove what Hunter was as a discoverer, we must also fairly state what he was not. He has been spoken of as the originator of the idea of a subtle imponderable principle operating in the fluids and solids of the organism, and causing the phsenomena of life. But such a principle, under various names and with various attributes, has been assigned as the cause of organization by Aristotle, Harvey, Willis, Cudworth, Grew, Van Helmont, and Stahl. As both Harvey and Hunter had spent laborious lives in earnest inquiries and repeated dissections and experiments, to ascertain relations between structure and function; as both had studied the changes which take place in the form and structure of animals from their embryo state to that of maturity ; and as both had carefully traced the successive phsenomena which occur in the egg during incubation,—the similarity of their opinions on the nature and powers of the vital principle is correspondingly close. Both arrived at the conclusion, that an animating principle exists and operates in the ovum prior to the formation of any organ of the future animal. Both attributed the power by which the fecund egg resists putrefaction, while the unprolific one decomposes, to a principle of life, which Harvey more precisely terms the " anima vegetiva."* Hunter, however, carries his researches a step further; he submits the fecund egg to a low temperature, and ascertains a new property, of which Harvey was ignorant, a power, viz., of resisting cold : he also shows that when once frozen, and killed by cold, the dead impregnated egg yields to putrefaction like the unimprcgnated one. Both physiologists observed that if the phasnomena of a vital principle were manifested in one part of the organization more than in another, it was in the blood. " For the blood," says Harvey, "is the first formed, and is the primary animate particle of the embryo; it is generated prior to the punctum saliens, before the first rudiment of the heart, and is endowed with the vital heat or principle before it begins to move, and from it does pulsation commence.

*"Plurimum itaque mecum ipse reputavi, qui fieret, ut ova improlificagallinae supposita, ab eodem calore extraneo corrumpantur, putrescant, et fcetida evadant; ovis autem fcecundis idem non contingat." Harveii De Generatione Jlnimalium Exercitatio 22. "Ovum itaque est corpus naturale virtute animali praeditum ; principio nempe motus, transmutationis, quietis, et conservations." Exercit. 26. " Cum enim in ovo macula prius dilatelur, colliquamentum concoquatur et praeparetur, plurimaque alia (non sine providentia) ad pulli formationem et incrementum instituantur, antequam quidpiam pulli vel ipsa primogenita ejus particula appareat; quidni utique credamus calorem innatum animamque pulli vegetativam ante pullum ipsum exsistcre ?" Exercit. 57. PREFACE. 15 For the thing containing is made to be serviceable to the thing contained. " Nor is the blood therefore to be call the primogenial part, because that in and from it the organ of pulsation is derived, but also because the. animal heat and vital principle are first implanted therein ; and in it does life consist. For where heat and motion first begin, there also life doth first arise and last expire. "—Harvey, On Generation, pp. 274, 275. This explicit and beautiful enunciation of the preexistence of the blood to the machine by which it is mainly circulated, and of its endowment of life, fell barren from the pen of Harvey (if we except the brief practice of transfusion to which it gave rise), and was forgotten, when Hunter resumed the inquiry. And why, it may be asked, was the doctrine of the vitality of the blood inoperative, as taught by Harvey? Because instead of establishing that doctrine by observations and experiments, from which alone it was susceptible of deriving further proof,—instead of applying the principle to the explanation of the phaenomena of disease, and to a modification and improvement of remedial measures, Harvey obscures and forgets the conclusion of his cooler moments of observation, and, as the learned Barclay well observes, excited by the discovery which had extended his fame so widely over Europe, and had reflected such lustre on his name and country, he expatiates on the blood as something divine; he has recourse to hyperbole, and describes its properties in the extravagant language of romance. Hunter, on the contrary, carries a series of calm and philosophical investigations on the vital properties of the blood to an extent which has never been surpassed ; he examines it under every condition, both in the vessels and out of the vessels, during circulation. and at rest, in health and in disease. He aims to establish the period in its formation at which it manifests the vital properties; and he fully details the changes which it undergoes, and the phaenomena which supervene in the rest of the organism when these properties are lost. Lastly, he tells us how the blood, by means of its vital properties, assists in the restoration of parts when injured or diseased. Hunter subjects the blood to both mechanical and chemical analysis, and endeavours to determine the characteristic properties of its different constituents. It was not known in his time upon which of these constituents the act of coagulation depended. Hunter took advantage of a case in which the red globules subsided, as in some cases thev do, more rapidly than usual, and skimming off the superincumbent colourless fluid, found that the fibrin, as it is now termed, immediately coagulated and formed a colourless clot.* A subsequent erroneous theory, which attributed the act of coagulation to the red globules, has recently been set aside by the application of an ingenious process for artificially separating the fibrin from the * Treatise on the Blood, &c, p. 32. l(j HUNTER ON THE ANIMAL O3C0N0MY.

blood disks before coagulation takes place, and the opinions of Hunter on this point have been fully established by the experiments of Muller. With respect to the serum, Hunter instituted a number of experiments and made many ingenious observations to determine the relative quantity of the coagulable to the uncoagulable part. His deductions as to the amount of nutrient albumen in the blood of animals of different ages, and under different circumstances, as regards exercise or rest, &c, formed, from observing the quantity of gravy or uncoagulable serosity which different roasted meats afforded, is highly characteristic of hisoriginal and ever active mind. In seeking to determine the respective importance of the different constituents of the blood, by the philosophical and most difficult inquiry into their respective periods of formation in tho development of the embryo, Hunter made the interesting discovery that the vessels of the embryo of a red-blooded animal circulated in the first instance colourless blood, as in the invertebrate animals. " The red globules," he observes, " seem to be formed later in life than the other two constituents, for we see while the chick is in the egg the heart beating, and it then contains a transparent fluid before any red globules are formed, which fluid we may suppose to be the serum and the lymph."* I well remember the feelings of surprise with which I listened while at Paris in 1832 to a memoir read before the Academy of Sciences by MM. Delpech and Coste, the object of which was the announcement of the same fact as a novel and important discovery. The statement of the French observers was received with all the consideration which its importance justly merited, without its being suspected that our great physiologist had half a century before embraced it, with all its legitimate deduction, in the extended circle of his investigations. In the same spirit in which he investigated the nature of the blood he also pursued his researches on the properties of the solids; he endeavours to determine the specific powers and vital phaenomena of the nervous system and of the stomach ; he compares these important parts of the animal body, with reference to the degree of energy with which their functions are manifested ; he considers the influence which they reciprocally exert in maintaining the vitality of the blood, and the relative dependence of the whole organism on the integrity of their vital powers. He also dwells at great length on the sympathies resulting from these mutual relations and dependencies. In all his physiological researches we may see that instead of dogmatising on the powers and virtues of an abstract essence, Hunter endeavours to analyse the vital forces peculiar to each organic element, and to classify, as it were, the phaenomena of which life consists. If we turn from Hunter's researches on life to his investigations * Treatise on the Blood, &c, p. 71. PREFACE. 17 on another equally difficult and recondite subject in general physiology, viz., Animal, or rather, Organic Heat, we see the same exercise of the powers of the same great and original mind. He first determines the relative extent to which the power of generating heat or resisting cold is enjoyed in the two grand divisions of organic nature, plants and animals: he next investigates the degree in which that power is possessed by different classes of animals; then the relation subsisting between that degree and the perfection and complexity of the organization with which the power is associated. He anticipates some modern physiologists in determining the different power of generating heat manifested by the same species at different periods of life, and advances a step further by considering the different powers of resisting cold which different parts of the same organized body possess in relation to their respective ages and periods of formation.* He lastly analyses, so to say, the different functions, to determine in what degree the production of heat depends on their exercise; and reciprocally, the influence of the temperature of the body upon the active and healthy maintenance of their function. Throughout all this beautiful and justly celebrated inquiry we see the philosopher conscious of the extent of his powers, and of the kind of knowledge which the right exercise of those powers was adapted to acquire. We now here perceive a trace of a desire to establish a theory of the nature of animal heat in the abstract. Let any one compare the language of Harvey or of Willis, while expatiating on the calidum innatum, with the following just remark: " I shall not," says Hunter, " attempt to settle whether heat is a body or matter, or only a property of matter, which appears to me to be merely a difference in terms, for a property must belong to something."f It is precisely in the same spirit that he conducts his researches on life; and I would say, after a very careful study of the writings of Hunter, that of all physiologists he is one to whom a dogmatic theory of abstract life can least be attributed. But by those whose notions of Hunter's doctrines are founded solely on a perusal of the posthumous " Treatise on the Blood" he is liable to be misconceived, and in opinions expressed from that limited acquaintance with his writings to be misrepresented. With the just ideas which Hunter had acquired of the laws of vitality and organic heat he was enabled to explain many of the phasnomena of digestion more satisfactorily than had been done by his predecessors Spallanzani and Reaumur. The following is a fair example of the different views and Kinds of knowledge which these experiments brought to the inquirv. Spallanzani had observed that digestion did not go on in reptiles below a certain temperature, he thought therefore that heat ♦ P. 158. t P- 162. 3 18 HUNTER ON THE ANIMAL CECONOMY. was necessary to assist in the dissolving processes of the stomach; Hunter, referring to the same fact, shows that the influence here is not merely chemical, but that the heat operates by first raising the sensitive powers, these then transmit the stimulus to the respiratory and circulating functions, and lastlyito the motive and other actions and faculties, and that the digestive organs are necessarily excited to corresponding actions, in order to supply the waste occasioned by the working of the machine, which the heat has thus called into play. Hunter more accurately determined, and first applied and rendered fruitful the fact which Grew incidentally mentions, viz., That it is the property of a living body or part to resist the action of the gastric juice ; and his celebrated paper '-'On the Digestion of the Stomach after Death," is a beautiful example of the application of his general view in physiology to the explanation of particular phaenomena. Of all his published writing, the paper on Digestion convey perhaps the best idea of the extent of Hunter's researches in Comparative Anatomy, and of the soundness of his reasonings in General Physiology. Hunter's claims to the originality of observations which have been reproduced as new by late physiologists, I have pointed out in the notes to these and other memoirs; and have particularly endeavoured to define the merit of Hunter as a discoverer in reference to the absorbent system. Hunter's published writings on the Nervous System bear but a small proportion to the extent of his anatomical investigations on this subject, especially as they are manifested in the philosophical series of preparations in the Gallery of his collection, in which the nervous system is traced through its progressive stages of complication, from the simple filaments of the entozoon and echinoderm, to the aggregated masses which distinguish the organization of man. The fibrous structure of the brain, the discovery of which, though due to Coiter as early as 1573, has sometimes been attributed to Reil and Gall, is displayed by Hunter in preparations made to show the fact (Nos. 1335, 1336), and is expressly mentioned in the description of the Anatomy of the Whale Tribe.* In treating of the comparative anatomy of the nervous system in his introductory observations to this division of his Collection,! Hunter rises to the following generalizations. He divides the animals which have brains, or visible aggregations of the nervous substance, into six classes, each characterized by a peculiar modification of the brain. The 'first class' has a brain in the form of a ring, through which passes the oesophagus, and from which the nerves arise, like radii from a centre. It consists of a pulpy substance, somewhat transparent, which is easily squeezed out when the brain is cut into. It

* P. 373. | Physiological Catalogue, vol. iii., p. 4. PREFACE. 19 is not enclosed in hard parts, and is not defended from pressure or injuries more than any other internal part. The examples of this type in his Museum are selected from the gastropodous class of Mollusca. The same condition of the nervous system we now know, from the researches of Cuvier, to characterize the whole of a vast division of invertebrate animals, including, amongst the highest organized of that division, certain species,— the dibranchiate Cephalopods,—in which the character, as expressed by Hunter, is affected by the development of a cartilaginous cranium for the protection of the cerebral ring ; but ulterior researches have not led to any modification of Hunter's description of the typical form of the brain in the Molluscous sub-kingdom. In the 'second class' the brain lies in the head of the animals; it is a pulpy substance, somewhat transparent, which gives it a bluish cast; from its lower part go out two large nerves, one passes on each side of the oesophagus, and they then unite into one, forming a knot at their union; they disunite again, and so unite and disunite alternately through the whole length of the animal, at every union giving off the nerves as from the brain. This structure, Hunter says, he suspects to answer both the use of a medulla spinalis and the great intercostal nerve. The examples of the class of animals adduced by Hunter as being characterized by this essential form of the nervous system are the leech, earthworm, aphrodita, centipede, caterpillar, scorpion, and lobster. Subsequent researches have shown that it exists in the barnacles, or Cirripedia, which most zoologists now rank in the same primary division with the Anellides, Insects, Arachnidans, and Crustaceans. In the first class of animals in this neurological arrangement (for in enunciating general propositions respecting any given organ the comparative anatomist becomes involuntarily, as it were, a classificator of animals as well as organs), Hunter observes, " we had the brain surrounded by soft parts only. In the second it was closely surrounded by soft parts, but these were surrounded by hard. In the 'third class' the brain has a case of hard parts for itself, called the skull." Now when Hunter made a brain relatively larger than in his first two classes—protected by a skull,—and continuous with a medulla spinalis extended down the back, and an endowment of the five senses,—the essential neurological characters of his third class of animals.—he erred in not applying them to his fourth, fifth, and sixth classes, as an attribute common to all, and one which distinguished each alike from the two lower classes. The appreciation of the great natural group characterized by a brain and spinal chord, situated on the dorsal aspect of the body, and protected by a vertebral case, was reserved for the sagacious penetration of Cuvier. However, in so far as Hunter limits his generalizations to the brain alone, he is consistent with himself, and exact in the differential 20 HUNTER ON THE ANIMAL OXONOMY. characters which he points out. The brain in fish, for example, or his ' third class,' is a very irregular mass, inconstant in its form and in the number of its parts ; still the " several parts which are similar to those in a superior class may be picked out;" the skull, moreover, is too large for the brain, and the interspace is filled by a cellular membrane, which Hunter compares to the arachnoid. In the 'fourth class,' the parts composing the brain " do not lie one upon another, but are very much detached and follow one another," in short, are characterized by their linear arrangement; a character, the accuracy o( which, as applied to the Reptilia, has been confirmed by all subsequent experience. It is interesting to observe how Hunter determines the nature of these different detached masses. He says, " The two anterior consist of the cerebrum ; the two middle, I should suppose, of the nates and testes, which I take to be the middle lobes detached, because in the bird they are more underneath, not so much between the cerebrum and cerebellum ; the posterior is the cerebellum, consisting of one body entirely."* Every eminence, Hunter further observes, has a cavity or ventricle in it. The linear arrangement of the masses of the brain is common both to fishes and reptiles; but the relation of those masses to the skull, and their variable number and proportions, according to Hunter, distinguish the brain in fish. He further observes that in the crocodile the parts of the brain are more closely connected, and that the skull is more in contact with it, in which respect it comes nearer the bird than do any of the other amphibia. The brain in the 'fifth class,' or fowl, Hunter characterizes by its greater relative size, and the superposition of its component masses. In the ' sixth class,' or quadrupeds, the brain is in general larger than in the preceding, and the parts more compacted, the whole mass being brought into nearly a globular figure. " The nates and testes are four small bodies, with no visible cavities; are not seen externally, but lie at the posterior end of the third ventricle."! In the observations printed in the present volume on the branches of the fifth pair which are distributed to the nose and ear, we cannot fail to observe that Hunter had entered on that track of inquiry, and perceived the governing principle or idea, which, more clearly appreciated and steadily retained by Sir Charles Bell, has since led to such important improvements in this department of physiology. Hunter premises his description of the nerves which supply the organ of smelling by calling attention to the constancy which pervades the anatomical conditions of the nerves, and states in general his belief that particular nerves have particular functions, in relation to their differences of origin, union, and distribution ;% but this simple enunciation, without the proofs and illustrations of which it was susceptible, became unproductive of its proper results, and appears to have been subsequently lost sight of by Hunter himself, * Physiological Catalogue, vol. iii., p. 7. t Ibid., p. 10. £ Pp. 204, 205. PREFACE. 21 when speculating on the nerves as internuntiate conductors of a materia vita diffusa. A knowledge of Hunter's opinions on the nervous system, derived only from the observations on that subject which occur in the Treatise on the Blood, might lead to the belief that he attributed to all the different nerves one common function; but after > perusing the distinct exposition of his views on this branch of physiology as recorded in the Animal (Economy, it appears to me that Hunter needed only to have resorted to experiment in this, as he did so successfully in other fields of physiological inquiry, to have established the nature and degree of the functional differences of these nerves, of which he describes the anatomical conditions giving rise, as he supposes, to those differences. He limits himself, however, in his illustration of the grand proposition, by anatomical examples only. He shows that organs like the eye and nose, which are endowed by means of one nerve with a special sense, derive their ordinary sensation from a second nerve having a different origin. This nerve he determines, in the case of the eye and nose, to be the fifth pair. He says the same mode of reasoning is equally applicable to the organ of taste, and he traces the corresponding superadded nerve to the ear. Hunter further distinguishes the sensations of the stomach and of the glans penis as being peculiar, and shows that as these peculiar sensations reside in particular nerves, so at whatever part of the nerve the impression is made it always gives the same sensation as if affected at the common seat of the sensation of that peculiar nerve. In another place Hunter makes the ingenious remark that the nerves which are specially designed to receive peculiar impressions convey the ideas of such impressions to the brain, in whatever way they may be affected or stimulated. Thus he says, " A mechanical impression on the retina produces nn impression of light; a blow on the ear the sensation of sound."* And later experiments have only extended this principle, by showing that whether the nerve be affected by mechanical, chemical, or electrical stimuli, it conveys the same sensation. Much importance has been attributed to these observations, on the supposition that they were new, and I have been induced to dwell thus long upon Hunter's contributions to the physiology of the nervous system, because in most of the recent works upon that subject he does not receive the credit which is due to him for having made them. The physiological discoveries of Bell, Magendie, Mayo, and MUller, have resulted from the combination of experiment with a philosophical consideration of the anatomical peculiarities of the nervous system. It was the neglect of experiment in this department of physiology which rendered Hunter unable to account for ♦Lectures on Surgery, p. 56-7, of the'present edition, and Parkinson's Huaterian Reminiscences, p. 12. 3* 22 HUNTER ON THE ANIMAL CECONOMY. the peculiarities which equally struck his mind as being connected in an intimate degree with the functions of the nerves. Had Hunter combined experiment with dissection when he traced the lateral branch of the nervus vagus in the cod, the eel, and the gymnotus, and wondered " that a nerve should arise from the brain to be lost in common parts, while there was a medulla spinalis giving nerves to the same parts," this probably would not have remained to him, as he expresses it, " one of the inexplicable circumstances of the nervous system."* Having been induced to dwell on the improved views which Hunter either established or suggested in different branches of physiology, I proceed next to advance a few instances of his discoveries in comparative anatomy, which, on the supposition that they were original, have contributed to add to the reputation of subsequent anatomists. 1. The organ of hearing in the sepia. The fact that this cephalopod possesses the organ in question is stated at p. 300 of the present edition of the Animal GSconomy, and it is said to differ from that of fishes. The discovery is attributed by Cuvier to Scarpa. 2. The semicircular canals of the Cetacea, described by Hunter in the paper on whales, a structure which Cuvier rightly states that Camper overlooked, but incorrectly claims the discovery as his own. 3. In the latest sketch of the history of comparative anatomy, prefixed to the French translation of Carus's Zootomie, John Hunter is introduced as the impudent self-appropriator of Camper's discovery of the air-cells in the bones of birds; and the historian of the science does not honour him with any further notice. Now the facts with reference to this subject are as follows: Camper's account of the air-cells in the bones of Birds was first published in the Dutch language in the year 1774, the same year in which Mr. Hunter's discovery was published in the Philosophical Transactions. The French memoir of Camper was not published till the year 1776, in the seventh volume of the Memoires Etrang. de I'Academie des Sciences de Pay-is. Hunter gives the date of his discovery as being in 1758; Camper his, in the year 1771. The numerous observations and experiments which their respective memoirs detail are not such as could hastily be got up for an unworthy purpose ; but as both memoirs (which differ materially in their general scope and the mode in v hich the subject is treated) were published in the same year, the honour of the discovery may fairly be attributed to both their authors. I might dwell on the philosophical comparison which Hunter makes between the abdominal air-cells of the bird and those of reptiles and fishes had he not in this instance been anticipated by Harvey. Harvey, however, vvas not aware that the respiratory * Animal O3conomy, p. 412-13. PREFACE. 23 system was extended in^o the muscular interstices and the cavities of the bones; the honour of which discovery must be assigned to Hunter and Camper, without the necessity of supposing that either had borrowed from the other. The preparations in the Hunterian Collection and the Manuscript Catalogues show that Mr. Hunter had discovered the peritoneal canals or openings in the eel, salmon, and the cartilaginous fishes, in the crocodile, and the continuation of the same peritoneal canals into the corpus cavernosum penis in the tortoise and turtle. The latter have been recently rediscovered by MM. Isidore St. Hilaire and Martin St. Ange. Hunter's printed works, preparations, manuscripts and drawings contain proofs of his discovery of the circulation of the blood in insects, and of the peculiar diffused irregular and extended venous receptacles in these and the crustaceous animals, in the latter of which their existence remains unnoticed, even in the latest works on the subject. In the Treatise on the Blood* we have an opportunity of judging, by the accuracy of the general propositions which he enumerates on this subject, of the extent of Hunter's researches on the comparative anatomy of the circulating system, and of the spirit in which he prosecuted the induction of particular facts. I cannot resist the quotation of the following passages which relate to the circulation in insects. "In the winged insects which have but one heart, as also but one circulation, there is this heart answering both purposes" (viz., the corporeal and the pulmonary circulations), p. 172. " Many of those which have one ventricle only have no auricle, such as insects; but there are others which have both a ventricle and auricle, such as fish, the snail, and many shell-fish; some of the last class have indeed two auricles, with only one ventricle.—" The heart " is placed in what is called the chest in the quadruped, bird, amphibia, fish, and the aquatic and terrestrial insect, but not in what may be called the chest in the flying insect. " The chest in the aquatic insect seems best suited to contain the lungs and branchiae, and therefore the heart is placed there; but as the lungs of the flying insect are placed through the whole body of the heart is more diffused, extending through the whole length of the animal." p. 174. " Where the veins entering into the heart are small in comparison to the quantity of blood which is wanted in the ventricles, then we have an auricle ; but when the veins near to the heart are large, there is no auricle, as in the lobster and generally in insects." p. 176. " la all animals which have an auricle and a ventricle, so far as I know, there is a bag (unattached) in which they are placed, called a pericardium ; but the insect tribe, whether aerial, aquatic, or terrestrial, have none, their hearts being attached to the surrounding parts by the cellular membrane or some other mode of attachment. * § 5., p. 171 of the present edition. 24 HUNTER ON THE ANIMAL O3C0N0MY. The heart " gives to the blood its motion in most animals, and in all it sends the blood to the organs of respiration ; in the flying insect it sends the blood both to those organs and to the body at large, but in fish to those organs only, the body at large in them having no heart. In the amphibia there is an attempt towards a heart both for the lungs and body, but not two distinct hearts. In the bird and quadruped there is a distinct heart for each." And again, " With respect to its use, it is in the most simple kind of heart to propel the blood through the body immediately from the veins, which blood is to receive its purification in this passage when the lungs are disposed throughout the body as in the flying insect." p. 179. The researches of Cuvier led him to conceive that there was a generally diffused, but passive, or non-circulated condition of the blood, coexisting in insects with the distribution of the breathing organs through the whole body. Hunter, on the contrary, while he rightly appreciated that condition of the circulating system in insects which related to their peculiar respiration, viz., that the venous blood was diffused apparently through the cellular membrane, in the interstices of the fat, air-cells, and muscles, and that the veins in insects might be called in some measure the cellular membrane of the parts;* yet he well knew the relations of these diffused receptacles of the venous blood to the dorsal heart, and the circulatory movement which was impressed upon the vital fluid by that organ. It is this remarkable error of Cuvier, with reference to the circulation in insects, that has given to the direct observations of the blood's motion by means of the microscope in the hands of Carus, Bowerbank, and other excellent observers, the character of a new discovery. Hunter first determined the bi-auricular structure of the heart in the batrachian caducibranchiate reptiles, which he included in the class Tricoilia of his classification of animals according to the structure of the heart. Hunter first discovered, by means of retrograde injections of the tubuli uriniferi, that these essential partsof the kidney extended to the superficies of that gland, and were not confined to the medullary substance. Meckel, who saw while in London the beautiful preparations establishing this fact (Nos. 1202, 1203, 1214, 1215, 1235), described them on his return to Germany to Muller',f who, in his recent elaborate work on the glands, acknowledges how important this observation was in establishing true notions of the structure of glands. Hunter extended his researches on the renal organ to the invertebrate classes, and shows " the kidney of the snail;" and the correctness of this ascription to the so-called mucous gland has been recently es abhshed by the observations of Professors Jacobson and de Blainvilie.

* See Physiological Catalogue, ii., p. 31 ; also the note at p. 221, vol iii of the present edition. v ' u,# U1,» 0I f De penitiori structura Glandularum fol. p. 95. PREFACE. 25 _ I have selected a few facts from amongst the multitude which Hunter ascertained in the progress of those investigations, by which he sought in the simpler modifications of the structures in the lower animals the true uses of the different organs which are combined to form the complex frame of man. I might lastly allude to the extraordinary nature and extent of Hunter's labours in another track of physiological inquiry, viz., that which unfolds the laws of generation and animal development; but as the work confided to me by the Council of the Royal College of Surgeons, viz., the description of the series of preparations on these subjects, which include nearly one-half of Hunters grand Physiological Collection, is still in progress, I defer the comparison of Hunter's labours in this field with those of his contemporaries until the whole body of the evidence of his discoveries can be laid before the public. The papers, however, which Hunter published in his lifetime, and which form the first part of the present volume, convey a most favourable idea of his views respecting this recondite branch of physiology. It is here that we find an attempt to explain congenital defects by reference to the transitory structures or metamorphoses of foetal life. It was a question in the time of Hunter how it happened that the gut in the hernia congenita came to be in contact with the testes. Hunter solved the question, by directing attention to the position of the testis in the abdomen, and to its relations to the other abdominal viscera, and to the peritoneum, a few months, before the expiration of the term of foetal development. He watched the progress of the gland to the scrotum ; saw it carrying along with it a peritoneal pouch like the sac of an intestine, and thus demonstrated, that if the closure of that sac was prevented by the contemporaneous passage of a loop of intestine, it must remain a common receptacle, both of the part which had naturally, and the part which had preternaturally, escaped from the abdomen. Hunter then goes on to show how the early and transitory condition of the tunica vaginalis in the human foetus, and also the still earlier abdominal position of the testes, are permanent structures in the lower mammalia. With respect to monstrosities in general, Hunter had drawn out a scheme for their classification, and had produced them by experiment. In the " Account of an extraordinary Pheasant" he states that every species of animal, and every part of an animal body, is subject to congenital malformation ; but he knew that such appearances were not attributable to a freak of Nature, or a matter of mere chance; for he observes that every species has a disposition to deviate from Nature in a manner peculiar to itself. It is this principle which forms the basis of the latest and most elaborate treatise on monsters,* a work which its author describes as being

* Histoire des Anomalies de l'Organization chez l'Homme et les Animaux, ou Traite" de Teratologie, par Isid. Geoffroy St. Hilaire: Paris, 8vo. 1832. 26 HUNTER ON THE ANIMAL C3CONOMY. "the result of his having established by a great number of researches, that monsters are, like the beings called normal, subject to constant rules." With respect to the cause or origin of monsters, Hunter referred it to a condition of the original germ, or, as he expresses it, "each part of each species seems to have its monstrous form originally impressed upon it." In the introductory observations to his extensive collection of malformed foetuses and parts, he assigns the grounds for this hypothesis, and at the same time enunciates one of the most remarkable laws of aberrant formations. " I should imagine," he writes, " that monsters were formed monsters from their very first formation, for this reason, that all supernumerary parts are joined to their similar parts, as a head to a head, &c, &c." In proof of the important general principles, at a knowledge of which Hunter had arrived, I have elsewhere quoted this passage, together with the following remarkable one from Hunter's descriptions of his drawings illustrative of the development of the chick. " If we were capable of following the progress of increase of the number of the parts of the most perfect animal, as they first formed in succession from the very first, to its state of full perfection, we should probably be able to compare it with some one of the incomplete animals themselves, of every order of animals in the creation, being at no stage different from some of those inferior orders; or in other words, if we were to take a series of animals from the more imperfect to the perfect, we should probably find an imperfect animal corresponding with some stage of the most perfect."* We may, I think, perceive, from the evident difficulty with which Hunter expresses the idea, that his mind was oppressed with both its novelty and vastness. Men's thoughts require to be familiarized with propositions of such generality before their exact limits and full application can be appreciated. Sufficient, however, has been adduced to prove the tendency of Hunter's labours, and that he possessed the highest qualifications as an investigator of Nature ; unwearied in induction, sagacious in grouping together analogous phaenomena, and ever striving to ascend from propositions of less to those of greater generality. Had the means and time been granted to Hunter to have made public the results of all his labours, or had his manuscripts enunciating, or indicative of, so many general principles been fairly appreciated and given to the world, our teachers of anatomy would not now, after a lapse of half a century, have but begun to explain to their students those beautiful laws of animal development, for the knowledge of which they are indebted to the labours of the professors in the noble schools of physiology in Continental Europe, where the spirit of Hunterian inquiries seems to have so long exclusively resided. But the period which has elapsed before those general laws began to be appreciated in the country where they were first detected, affords, perhaps, one of the strongest indications of the great advance which Hunter had made in physiological science. * See preface to the Physiological Catalogue, vol. i. p., ii. PREFACE. 27 It would be a strange exception to the usual result of an extensive knowledge of comparative anatomy, combined with a tendency to express in general propositions new physiological and structural truths, if the possession and application of that knowledge with that tendency had so led to some corresponding advance towards a natural system of zoological classification. Accordingly we find the contemporaries of Hunter ascribing to him the highest accomplishment which the zoologist can aspire to, that of discerning the natural affinities of a nondescript object; and this in terms and on occasions which seem to imply a general admission of his possession of such attainments. When the rare quadrupeds of Australia were first brought to England, presenting, as they did, to the eye of the zoologist anomalies and peculiarities not less striking than those which perplexed the botantist in the plants from the same part of the world, it was to Hunter that they were referred. " There was no person," says Dr. Shaw, " to whom they could be given with so much propriety, he perhaps being most capable of examining accurately their structure, and making out their place in the scale of animals."* It may not be uninteresting to contrast the sketches of systems of zoological arrangement which Hunter has left, with the Linnaean method which prevailed in his time, and which continued to prevail until superseded by the labours of Cuvier, specially and unremittingly directed to that end. We have already seen that Hunter's attempts to enunciate general propositions respecting the nervous system led him to detect the condition characteristic of the molluscous sub-kingdom, and to speak of the animals with " the brain in the form of a ring, " &c, as a class. In still more definite terms he describes the condition of the nervous system which characterizes the articulate Invertebrata. With respect to that higher type of the nervous system, which is manifested in its aggregation into spinal and cerebral masses, we have seen that Hunter alludes to it as distinguishing only the class of fishes from his first and second classes, or the Molluscous and Articulate divisions as they are now termed ; and that he failed to perceive that all the other vertebrate classes were equally characterized by it. To Hunter, however, we must award the merit of having first obtained a perception of the distinct group formed by the higher organized vermes of Linnaeus, and their essential organical character. Hunter had also investigated the structure of zoophytes, in which no annular brain can be detected ; he had conceived the idea of animals in which the nervous matter, or something analogous to it, a materia vitce diffusa, was dispersed throughout the system. And we find another learned contemporary of Hunter,'in ascribing a diffused condition of the nervous matter to the Taeniae, bearing testimony that Hunter had entertained

* Zoological Appendix to White's Voyage to New South Wales, p. 468 of the present work. 28 HUNTER ON THE ANIMAL CECONOMY. a similar opinion, and had applied that character of the nervous system to many of the lower tribes of animals.* The distribution of animals according to the nervous element of their organization, is, however, but one of several attempts at classification which Hunter made. The next scheme which we shall quote is one founded upon modifications of the generative function.f Hunter's first class, or Vivipara, corresponds with the Zootoka of Aristotle, and the Mammalia of Linnaeus ; these animals develop their young in the uterus, he says, from a mixture of male and female influence, and bring forth a living offspring. The second class, or Ooovivipara, is a subdivision of the Ootoka or Ovipara of Aristotle, and "hatch their young from an egg in the oviduct, as vipers, slow-worms, some lizards, newts, and the dog-fish." The third class includes the Ovipara, or " such animals as exclude their eggs, which are afterwards hatched out of the body ;" but this character, as Hunter justly observes, " takes in a wide field." Fourthly, he says, " We have animals which propagate by slips, and that in two different ways, one by a piece cut off, the other by branches growing, and these falling off, and producing a distinct animal." Hunter here rightly regards the fissiparous and gemniparous modes of generation as modifications of the same reproductive process which is characteristic of that lowest group of animals previously indicated by the molecular condition of the nervous system, and " where every other principle of the animal is diffused through the whole," a condition which in the animal kingdom seems essential to the possession of the property of fissiparous reproduction, or to a division of the whole body with a continuance of the vital properties in the parts. Hunter seems, however, to have felt how unsatisfactorily and artificial was the classification founded on modes of generation, for he adds in the manuscript in which-the above sketch is given, " Animals of any particular class have not one way only of propagating their species, excepting the more perfect, or first class according to hearts, for we have the second and even the third class aping the first, and attempting to be viviparous, as vipers, lizards, and some fishes, as the skate." He might have added examples of ovoviviparous animals, from the molluscous, articulate and radiate classes,—classes which in every other respect are most dissimilar. This idea of an arrangement of the animal kingdom from modifications of the generative function was afterwards carried out by Sir Everard Homeland applied by him to the definition of the narrower or subordinate groups. But as of all single characters the generative system affords°the most arbitrary and unnatural distinctions, and corresponds least with the modifi-

* See Carlisle, On the Structure and CEconomy of Taeniae, Linnaean Transactions, vol. 11., p. 253, and Treatise on the Blood, p. 116, of the present edition. t See Introduction to the Physiological Catalogue, vol. iii., p. vi. X See his Systema Re°ni Aninudis nunc primum ex ovi modificationibus propositum, Lectures on Comparative Anatomy, vol. iii., p. 535. PREFACE. 29 cations of the rest of the organization, a classification of animals based upon it is least adapted to afford any of the conveniences of even an artificial system. In the Systema Naturce of Linnasus the first of the characters by which the six classes of animals are distinguished is derived from modifications of the structure of the heart, as follows:

" Mammalia, Cor biloculare, biauritum ; Aves, Cor biloculare, biauritum ; Amphybia, Cor uniloculare, uniauritum; Pisces, Cor uniloculare, uniauritum ; Insecta, Cor uniloculare, inauritum ; Vermes, Cor uniloculare, inauritum."

But Linnaeus combines the cardiac character with others derived from the nature of the blood, the condition of the respiratory organs, the structure of the mouth and generative organs, the nature of the integuments, &c, and thus makes an approach to a natural system of arrangement. Hunter, in his distribution of animals into different classes ac cording to the structure of the heart, uses the cardiac character singly, and produces a purely artificial arrangement; but his superior anatomical knowledge manifests itself in the accuracy with which he defines the condition of the circulating organ characteristic of the different groups. His first class includes the Mammalia and Aves of Linnaeus, and he proposes to call it Tetracoilia, the heart having four cavities, viz., two ventricles and two auricles. The second class, Tricoilia, includes those animals which have a heart with three cavities, viz., one ventricle and two auricles, and corresponds with the Amphibia of Linnaeus. The anatomical inaccuracy in the Linnasan character, although so early corrected by Hunter, long retained its ground in the systematic works of continental naturalists, and continued to be erroneously applied to the Batrachian section of the Linnaean Amphibia until a very recen period.*

* The two auricles were after the time of Linnaeus successively assigned in systemalic works to the Chelonia and Sauria. Blumenbach long continued to assert that serpents, at least those of Germany, had but one auricle ; Cuvier allowed them two, but denied this higher structure of the heart to the Balrachia .- " Us n'ont au cceur qu'une seule oreilletteet un seul ventricnle." Regne Animal, ii., p. 101, edit. 1829. Meckel also ascribes this structure to the generality of the Batrachia: "Die Batrachier haben die einfachste Herzform. Das Herz besteht sehr allgemein nur aus einer Vorkammer und einer Kammer." Vergl. Anat., band v., p. 215. The more complicated structure of the heart was, however, truly described in the anourous Balrachia by Dr. John Davy in 1825; his observations were confirmed by Prof. Weber in 1832; and in April, 1834, I communicated to the Zoological Society the result of a series of examinations of the hearts of the Batrachia, which proved that the whole order, including the perennihranchiate species, had distinct auricles for the pulmonic and systemic blood, since which time the tripartite structure of the heart has been universally assigned to the Batrachia. 30 HUNTER ON THE ANIMAL Q3CONOMY. The third class, or Dicoilia, includes those which have two cavities in the heart, or one ventricle and one auricle, and consists of the gill-fish. The sharks and rays were included by Hunter in this class, but the diccelous or bipartite structure of their heart presented no obstacle to their junction with the Amphibia in the Linnaean arrangement. Hunter's fourth class, or Monocoilia, characterized by a heart with but one cavity or ventricle, without an auricle,, is restricted to insects of all kinds, i. e. to the articulate animals included by Hunter in his second class according to brains. By Linnaeus the character is applied to all invertebrate animals without exception. Hunter, with more truth, defines a fifth class of animals, by the name of Jicardia, "whose stomach and heart are the same body, as in the blubber (Medusa) and polypus." But even with this improvement, the Cardiac arrangement of animals, as proposed by Hunter, is very incomplete. The whole division of the molluscous animals is left out of the system. This did not, however, arise from a want of the knowledge of the structure of the heart in those animals. Hunter well knew the complex condition of the circulating organ in the cuttle-fish, a condition which, had he rigorously carried out his scheme of classification according to hearts, would have indicated a class above the mammalia, and to which the name of Heptacoilia might have been applied, since there are three distinct ventricles, one systemic and two pulmonic, and four auricles or venous sinuses in this and other dibranchiate cephalopods. In the snail and other gastropods Hunter had recognised a structure of the heart as complex and perfect as in fish, but having a different relation, both as regards function and position, to the respiratory organ.* In still lower Mollusca Hunter had detected the existence of two distinct auricles, with one ventricle ;f but his perception of the physiological relations of these different cavities prevented him from associating the mussel with the tortoise, on account of this tricoelous structure of the heart. We may thus perceive amidst the defects of this system of arrangement an evident advance towards a more natural distribution of animals, especially of the invertebrata, than that which was generally accepted at the period when Hunter wrote. We associate this progress with Hunter's superior knowledge of the organization and ceconomy of animals as its just and natural cause, and we proceed to adduce additional evidences of Hunter's attempts to frame a natural arrangement of animals. Perceiving that the modifications of the heart alone were inadequate to the formation of a natural and symmetrical classification of animals, he next tested the efficiency of characters taken from conditions of the respiratory system, and proposed the following scheme: "Theirs* class includes all those animals which have lungs with cells through the whole, and a diaphragm. + On the Blood, vol. iii., p. 172. f Ibid., p. 172, PREFACE. 31 " The second class, all those which have their lungs attached to the ribs, so as to confine them to their place. " The third class, all those whose lungs come into the belly and are loose. " The fourth class, all those whose lungs are in their necks, called gills. " The fifth class, all those whose lungs are in their sides."* In this scheme we have most exact and concise characters of the four classes of vertebrate animals, as afforded by the breathing organs; and in this case Hunter was enabled by his profound anatomical knowledge to rise far above Linnosus. In the Systemce Natures, the Mammalia and Aves, which correspond with Hunter's first and second classes, according to the organs of respiration, have both the same characters assigned to them, " pulmones respirantes reciproce," while the Amphibia, to which Hunter's third class corresponds, are said by Linnaeus to have " pulmones spirantes arbitrarie." Neither Hunter nor Linnaeus, however, arrived at the perception of that condition of the respiratory organs which characterizes their first four classes in common, viz., that the breathing organs communicate with the mouth; nor am I aware that the Vertebrata have ever been distinguished in any system as oral breathers, in contradistinction to the Mollusca, which may be termed anal breathers, and to the Articulata, which respire by apertures or branchial organs arranged symmetrically at the sides of the body. We have thus traced Hunter in his character as a systematic zoologist through a series of attempts at the arrangement of the animal kingdom, in which, like the indefatigable Adanson in a sister science, considering each organ by itself, he formed, by pursuing its various modifications, a series of groups characterized by that organ alone ; and doing the same for another organ and another, thus constructed a collection of systems of arrangement, each artificial, because each was founded upon the variations of a single assumed organ. It would, however, be doing injustice to Hunter to adduce the evidences of these attempts only. In that division of the animal kingdom where he had pushed his researches furthest, he aims to establish a more natural classification, by tracing the variations of all the important organs, and keeping in view the different value of each character; and thus he enunciates several general anatomical and physiological truths. The following are the characters which he assigns to the different classes of the animals now called Vertebrate. " The properties of the First Class, which includes both sea and land animals, are " Heart, made up of four cavities, essential. " Lungs, divided into small cells, and confined to a proper cavity,

* Physiological Catalogue, Introduction to the Third Volume, p. v. 32 HUNTER ON THE ANIMAL CECONOMY. the enlargement of which is the cause of respiration ; essential, Respiration quick (and I believe this is the only class in which it is so); essential. "Give suck; essential. " Parts of generation, made up of testes and one penis in the male ; the testes sometimes within and sometimes without the abdomen, but pass forwards. Clitoris, vagina, uterus or uteri, Fallopian tubes, and ovaria, in the female: all essential: "Kidneys, high up in the abdomen; circumstantial. " Organ of hearing, an external canal to the ear, membrana tympani concave externally,* a cochlea ; circumstantial. " The animals of this class are by much the most perfect, whether sea or land. There is a gradation from the land to the sea animals, viz., otter, seal, hippopotamus, whale. " The Second Class is confined to the Birds entirely. I do not know of any animal of this class but what has all the characteristics of the bird. They vary less in any of their parts than the first class.| " Lungs, attached to the ribs, that they may move with them: lungs perforated ; membranous bags in the abdomen that receive air in respiration; something like a diaphragm. "Parts of generation, ova crustaceous; one oviduct; one penis, and that grooved; no bladder. Oviduct in the female, and penis with the vasa deferentia in the, male, all open in the same cavity with the anus. " Liver, divided into two lobes ; cyst-hepatic ducts. " Organ of hearing, little external passage to the ear; membrana tympani convex externally, but one bone (ossiculum auditus); no cochlea. "Feathers; wings; two legs; long neck: bill; membrana nictitans ; bursa Fabricii. " There is none of this class that belong entirely to sea animals; but this class may be said to possess in some measure three elements, viz., air, earth, and water; but they live no more in the air than other animals, for it is only for their progressive motion. " Inrlhe Thi.rd Class we sna11 find some parts similar to the second. The third class may be divided into two, for they are not exactly alike, but one seems to partake of the second and third ; as it were, made up of both. The first division of the third class, then, is the Lizard and Serpent kind. They have " Heart, two auricles, one ventricle, two aortas which unite in the abdomen.

ofSn.frZw^r6 ^ WrJi5n be/°re Mr< Hunt«had dissected the organ 01 rearing in the whale. See p. 380, and note*. e

mieux° chLcteHs^ 'cSV? *? i*" C,"8e8 d'animaux' celle des ™eaux est la E* i p 310 S eSpeCCS Se ressemblent le plus.»_iterne PREFACE. 33 " Lungs, loose bags, which lie in the thorax and abdomen, only partially divided. No diaphragm. " Kidneys, in the lower part of the abdomen. No bladder.* " Parts of Generation, two penises, grooved,! which are in the tail. Some oviparous, eggs without shells; others viviparous, but not as the First Class. " Some have legs, others none; some a membrana tympani, which is convex outwardly, as the lizard; others none, as the snake. " The other part of this class, which may be termed the Fourth, or the Amphibious, are more closely allied to Fish than what the fish of the first class are.J These are the common amphibious animals, viz. frogs, turtles, efts, &c. This is also very similar to the two former, and is nearly, as it were, a mixture of both, yet the most essential parts belong, or are similar to the last. " Heart, two auricles, as in the Third ; one ventricle, as in the Third; aorta, as in the Third. " Lungs, as in the Third. " Kidneys, as in the Third. " Part of generations, one penis, as in the Second Class ; penis grooved, as in the Second and Third. Some oviparous, as the frog; others vivaparous as the salamander. " Organ of Hearing, some have a membrana tympani, as the frog ; others none, as the tortoise.§ " The Fourth or Fifth Class (according as the two preceding are regarded as subdivisions of one class, or as two distinct classes) consists of Fishes, and is very distinct from the former so far as I know."

The manuscript from which the preceding remarkable passages are quoted, and which is printed entire in my Prefatory Observations to the Third Volume of the Physiological Catalogue, contains no characters of the Class of Fishes, nor any relating to the Invertebrate Classes. It is in the definition of these latter classes, and in the determination of the wider divisions of the Invertebrata, which were equivalent to the entire vertebrate group, that Cuvier chiefly surpassed Hunter as a systematic zoologist. Yet, as I have before observed, Hunter rises above Linnaeus even in this department : he had seized the great character of the molluscous subkingdom afforded by the nervous system, and had well defined some of the subordinate groups, more especially that which Lamarck afterwards termed Tunicata, and which Cuvier denominates

* This character is not applicable to the lizards; but the crocodile agrees with the serpents in having no urinary bladder. t The crocodile has but one. . \ i. e. Those of the first class which are shaped like fish, and live in water,

^^TheSes and tortoises, or Chelortian reptiles, as they are now termed, have a closer affinity to the lizards than to the Batrachia, or frogs and salamanders. 34 HUNTER ON THE ANIMAL Q3CONOMY. " Actphates sans Coquilles," but which Hunter, more correctly, termed " soft-shelled," having perceived the analogy of their external elastic tunic to shell; and having detected, with admirable skill, the relations subsisting between the Ascidia3 and Salpae in diflerent individuals dissected by him, of which dissections there remain not only the preparations, but several beautiful designs, with the original descriptions.* Of Hunter's appreciation of the progression of affinities we have an example in his sketch of the transition from the terrestrial to the aquatic Mammalia ; and I do not doubt that ere long zoologists will uniformly agree in the propriety of passing from the hippopotamus and its pachydermatous congeners to the dugong and the true Cetacea, instead of interposing the Ruminantia between the Pachydermata and Cetacea, as in the Cuvierian system. Of his mode of considering the affinities of two great and equal groups, Hunter has left the following specimen, which he quaintly designates'; Of the similarity of the Fowl with the three-cavityhearted gentry, called Amphibia." " Thelungs of the fowl open into their air-cells or bags that are in the cavity of the belly. The lungs in the Amphibia are continued into the belly, are cellular at the upper part, but in most, as the snake, become smooth bags at the lower end, as it were, answering the same purpose as the abdominal bags in the fowl. The cells of the lung-part are large. "No proper Diaphragm in either; but fowls have something similar to one.f "The Gall is green in both. " The Kidneys are placed in what may be called the pelvis; in both are conglomerated in a particular manner; have the ureter ramifying through their whole substance, and entering into the rectum. The urine is a chalky substance in many of both, and a kind of slime in others. " The Testes are situated in the abdomen in the male of both. " The Vasa deferentia enter the rectum in both. " The Penis is grooved in both. " Both oviparous. " Structure of Ear similar in both. " Heart very diflerent. "

These writings fully attest the enlarged views which Hunter entertained of comparative anatomy, and of its application not only to the establishment of sound theories of the functions and relative influences of the diffeernt organic systems in the animal body, but also of a natural distribution of different animals into classes arranged according to their affinities. It is in this respect that he has more especially surpassed those of his countrymen who have immediately succeeded him in the same field of inquiry, and whose

* See Plates 5, 6, and 7, vol. i. Physiological Catalogue. f See p. 196. PREFACE. 35 labours in comparative anatomy have not been productive of adequate results, chiefly from being restricted to the narrower channel of their physiological application. The museum of Hunter is the chief, but not the sole depository of the dissections by which he established the general principles to which we have alluded. Hunter had passed his thirtieth year before he had collected a single preparation for himself. All that he had made before that time were added to his brother's collection, which is now the ornament of the University of Glasgow. In commencing his independent labours, in anatomy, he conceived the idea of a collection, in which the illustrations of the human organization should form a part only of a general display of all the types and modifications of animal structure, and practically he was the first who reduced the scattered facts of comparative anatomy to a connected system. When Hunter had brought his museum to an approximate degree of perfection,* he then set apart certain days, in which he exhibited and explained to some chosen minds which could respond to the conceptions of his own, his great scheme, embracing the demonstration of all the leading modifications of every organ of the animal body, and of the different stages which each organ undergoes in its development, to fulfil the functions it is required to perform in the highest organisms. Amongst the enlightened men who enjoyed the inestimable advantage of listening to the explanations which the founder of the collection gave of his own labours, and of their scope and tendency, were Camper, Poli, Scarpa, and the now venerable Blumenbach. Camper, as a contemporary, and in some respects a rival of Hunter, may have been less influenced in the general tenor and success of his investigations in comparative anatomy, by this circumstance, than the last named and younger naturalists and physiologists. We cannot but suppose that the spectacle of the organization of somanyrare marine animals, beautifully displayed by so consummate a practical anatomist as Hunter, must have had a lasting influence on the mind of Poli; and it is not, perhaps, assuming too much to trace to this source the taste for anatomy and the stimulus to the indefatigable and minute dissections, of the Mediterranean mollusca, and the magnificent illustrations of their organization, which have justly immortalized their author. In contemplating the gradational and connected series of the organs of animals, which Blumenbach must have witnessed for the first time in the museum of Hunter, that learned and accomplished physiologist was doubtless led vividly to appreciate the cumulative force with which comparative anatomy urges the onward progress of physiological science when all its scattered facts are concen-

* In the year 1787. See Home's Lectures on Comparative Anatomy, vol. i. p. 7. and vol. i. p. 78 of the present edition of Hunter's Works. 36 HUNTER ON THE ANIMAL gECONOMY. trated into one orderly system. In his subsequent publications of the first systematic treatise of comparative anatomy the erudition of Blumenbach supplied manv of those links in the series of animal structures which Hunter derived from Nature's original sources. In estimating, therefore, the share which Hunter had in advancing comparative anatomy and physiology, his annual demonstrations of his collection to such individuals as we have instanced must not be overlooked. We may admit that while so vast a proportion of the stores of his experience lay buried in unpublished manuscripts, his strue station in the temple of Science could hardly be discerned; but, independently of these manuscripts, we cannot hesitate in allowing that his published works, full of profound and original views, combined with the spectacle of his wonderful dissections, must have effected more than had been done by any previous author towards raising the science of comparative anatomy in the scale of human knowledge. Now, however, we have to estimate the scientific character of Hunter from more extended grounds. Enjoying the same privilege of consulting his museum, which the contemporaries of Hunter so highly esteemed, we also possess the advantage of studying it with the aid of those explanations of its scope and nature which its great founder had left with a view to ulterior publication. Thanks to the devotion of the last of Hunter's pupils to the memory of his great master, the evidences of Hunter's discoveries and labours, as recorded in his collections, are in a better state of preservation at this moment than they were nearly fifty years ago, when they first fell to the care and charge of Mr. Clift. And here I embrace with pleasure the opportunity of expressing my grateful thanks to that gentleman for the kind aid which I have on every needful occasion received from him during the impression of the present work, and of recording my deep sense of the advantages which I have derived from a long intercourse with one whom I ever shall regard as the best of friends and worthiest of men. It is to the zeal and industry which induced Mr. Clift to transcribe portions of the Hunterian manuscripts, at a period when he little suspected their ultimate fate, that we owe our additional knowledge of the philosophical views which Hunter entertained of the application of anatomical facts, and of the general principles which he had deduced from them. As such of these extracts from the Hunterian Manuscripts as have been quoted in the present work have already been printed in the Catalogues of the Hunterian Collections published under the auspices of the Council of the Royal College of Surgeons, it is competent for any one to judo-e of the grounds on which I have endeavoured to show that Hunter, as a comparative anatomist, merits a higher, and altogether different station in science than has been awarded to him by Cuvier. Instead of viewing Hunter as one who had merely contributed a secondary proportion of detached facts to the general but unarranged PREFACE. 37 stock of materials in comparative anatomy, it appears to me that he marks a new epoch in its history, and that the historian of the natural sciences has just and sufficient grounds for regarding Hunter as the first of the moderns who treated of the organs of the animal body under their most general relations, and who pointed out the anatomical conditions which were characteristic of great groups or classes of animals: as one, in short, throughout whose works we meet with general propositions in comparative anatomy, the like of which exist not in the writings of any of his contemporaries or predecessors, save in those of Aristotle. PvICHARD OWEN. November 15th, 1837.

N.B. The Editor's Notes are distinguished from the Author's by being placed within brackets, CONTENTS. Page Preface of the Editor ........7 1. Description of the Situation of the Testis in the foetus, with its descent into the Scrotum ...... 41 2. Observations on the Glands situated between the Rectum and Bladder, called Vesiculae Seminales .... 58 3. Account of the Free-martin ...... 70 4. Account of an extraordinary Pheasant .... 79 5. Experiments to determine the effect of extirpating one ovarium upon the number of Young produced . . • .85 6. Case of a young Woman who poisoned herself in the first month of Pregnancy, with a description of the Uterus . . 89 On the Structure of the Placenta.....93 Observations on the Placenta of the Monkey . . 103 Account of a Woman who had the Small-pox during Pregnancy, and who seemed to have communicated the same Disease to the Foetus.........105 Some Observations on Digestion !. . . • • U2 On the Digestion of the Stomach after Death . . 144 12. On a Secretion in the Crop of breeding Pigeons, for the nourishment of their Young ...... 149 13. Observations on the Gillaroo Trout, commonly called in Ireland the Gizzard Trout......» 151 14. Experiments and Observations on Animals with respect to the power of producing Heat ... ... 155 15. Experiments and Observations on Vegetables with respect to the power of producing Heat ....•• 1'' 16. Proposals for the Recovery of Persons apparently drowned 185 17. Account of certain Receptacles of Air in Birds, which communicate with the Lungs and Eustachian Tube . . • 194 18. Description of the Nerves which supply the Organ of Smelling 204 19. Description of some Branches of the Fifth Pair of Nerves 7. 8. 9. 10. 11. 20. Croonian Lecture on Muscular Motion, No. I. 21 22. 23. 24. 25. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. Do. No, No, No, No. II. III. IV. V. No. VI. 209 211 238 254 262 265 277 40 HUNTER ON THE ANIMAL (ECONOMY. PaRe. 26. On the Use of the Oblique Muscles .... 282 27. On the Colour of the Pigmentum of the Eye in different Animals......... 285 28. On the Crystalline Lens, or some Facts relative to the late Mr. John Hunter's Preparation for the Croonian Lecture . 292 29. Account of the Organ of Hearing in Fishes . . l- 297 30. Experiments on Absorption by Veins .... 303 31. Experiments and Observations on the Growth of Bones . 319 32. Observations tending to show that the Wolf, Jackal and Dog are all of the same species ...... 323 33. Observations on the Structure and CEconomy of Whales . 334 34. Notes on the Anatomy of the Jerboa .... 391 35. Anatomical Description of the Amphibious Bipes of Ellis (Siren lacerlani, Linn.) ....... 392 36. On the Electric Property of the Torpedo . . . 396 37. Anatomical Observations on the Torpedo . . . 404 38. Account of the Gymnotus electricus .... 408 39. Observations on Bees ...... 415 40. Anatomical Remarks on a New Marine Animal (Serpula gigantea, Pallas)........456 41. Observations on the Fossil Bones presented to the Royal Society by His Most Serene Highness the Margrave of Anspach 459 42. Descriptions of some Animals from New South Wales . 468 Of the Kangaroo (macropus major, Shaw) . . 472 Of the Potoroo (Hypsiprymnus murinus, Illiger) . 474 Of the Hopoona Roo (Petaurus Taguanoides, Desmarest 175 Of the Wha Tapoua Roo (Phalangista Vulpina, Geoffroy) 476 Of theTapao Tafa (Phascogale penicillala, Temminck) . 477 Of the Dingo (Canis Australasias) . . . 479 t A TREATISE OS THE ANIMAL (ECONOMY. 1. A DESCRIPTION OF THE SITUATION OF THE TES- TIS IN THE FCETUS, WITH ITS DESCENT INTO THE SCROTUM.

A discovery in any art not only enriches that with which it is immediately connected, but elucidates all those to which it has any relation. The knowledge of the construction of a human body is essential to medicine, therefore every improvement in anatomy must throw additional light on that branch of science. These improvements strike more forcibly if they are on subjects quite new or little understood ; and this effect is well illustrated by the advantages which pathology has derived from the discovery of the lymphatics being the absorbent system; and likewise by that case of hernia, where the intestine lies in contact with the testicle ; which has been perfectly explained by the discovery of the original seat of the testicle being in the abdomen. ►Several years before Haller's Opuscula Pathologica were published, my brother informed me, that in examining the contents of the abdomen of a child, stillborn, about the seventh or eighth month, he found both the testicles lying in that cavity, and mentioned the observation with some degree of surprise. By this we are enabled to account for a circumstance that sometimes happens in the scrotal hernia, as depending on the discovery that the testis is formed in the abdomen, and which we could never explain to our satisfaction till the publication of the Opuscula, to which Dr. Hunter alludes, (Commentaries, page 72,) in the following words: " In the latter end of the year 1755, when I first had the pleasure 5 42 HUNTER ON THE ANIMAL CECONOMY. of reading Baron Haller's observations On the Hernia Congenita,* it struck my imaginationf that the state of the testis in the foetus, and its descent from the abdomen into the scrotum, would explain several things concerning ruptures and the hydrocele, particularly that observation which Mr. Sharp had communicated to me, viz., that in ruptures the intestine is sometimes in contact, with the testis. I communicated my ideas upon this subject to my brother, and desired that he would take every opportunity of learning exactly the state of the testis before and after birth, and the state of ruptures in children. We were both convinced that the examination of those facts would answer our expectation, and both recollected having seen appearances in children that agreed with our supposition, but saw now that we had neglected making the proper use of them. " In the course of the winter my brother had several opportunities of dissecting foetuses of different ages, and of making some drawings of the parts; and all his observations agreed with the ideas I had formed of the nature of ruptures, and of the origin of the tunica vaginalis propria in the foetus. But till those observations were • repeated to his satisfaction, and were sufficiently ascertained, he desired me not to mention the opinion in my lecture ; and therefore, when treating of the coats of the testis, and of the situation of the hernial sac, &c, I only put in this temporary caution, that I was then speaking of those things as they are commonly in adult bodies, and not as they are in the foetus: and at last, when I was concluding my lectures for that season, in the end of April 1756, with a course of the chirurgical operations, I gave a very general account of my brother's observations, and showed both the drawing of fig. 2, which was then finished, and the subject from which it was made." The following observations on this subject were taken from my notes, and published by Dr. Hunter in his commentaries to which I have added some practical remarks. " Until the approach of birth, the testes of the foetus are lodged within the cavity of the abdomen, and may therefore be reckoned among the abdominal viscera. They are situated immediately below the kidneys, on the fore part of the psoae muscles, and by the side of the rectum, where this intestine is passing down into the

* Alberti Halleri Opuscul. Pathohg., Lausan. 1755, 8vo., page 53, &c. f [Although Haller was in doubt as to the exact period of the descent of the testis, and in error as to the cause of that phenomenon, yet he accurately describes, in the original paper here alluded to, the original relations of the gland to the peritoneum and abdominal viscera, and the formation of the tunica vaginalis, and thus applies the facts which he had discovered to the explanation of the disease he was considering. " Herniarum, ni fallor, congenitarum modus hinc elucescit, quo generantur. Patulus est processus peritonaei sub renibus positus, qui expectat testem invitatqne aperto ostio, atque eo deorsum ex solita lege pulso urgetur, inque scrotum una descendit. Cum autem his in corporibus testes eodem cum intestinis sacco omnino contineantur, nihil est singularis sive inexpectati si ea in apertum saccumalevi vi depressafuerint." (Opusc. Patholog.,p. 56.) 'in this paper there are references to the older authors who had noticed the abdominal position of the testes in the foetus.] SITUATION OF THE TESTIS IN THE FCETUS. 43 cavity of the pelvis; for in the foetus, the rectum, which is much larger in proportion to the capacity of the pelvis than in the fullgrown subject, lies before the vertebras lumborum as well as before the os sacrum. Indeed the case is pretty much the same with regard to all the contents of the pelvis; that is, their situation is much higher in the foetus than in the adult. The sigmoid flexure of the colon, part of the rectum, the greatest part of the bladder, the fundus uteri, the Fallopian tubes, &c, being placed in the foetus above the hollow of the pelvis in the common or great abdominal cavity. " While the testis remains in the abdomen its shape or figure is much the same as in the adult, and its position or attitude the same as when it is in the scrotum; that is, one end is placed upwards, the other downwards ; one flat side is to the right, the other to the left; and one edge is turned backwards, the other forwards; and the vessels enter the posterior edge alike in both the foetus and adult. As the testis is not so immediately inclosed in the surrounding parts while it is in the loins, its position may be a little variable, and the most natural seems to be when the anterior edge is turned directly forwards; but as the least touch of anything will throw that edge either to the right side or to the left, then the flat side of the testis will be turned forwards. It is attached to the psoas muscle all along its posterior edge, except just at its upper extremity; and this attachment is formed by the peritoneum, which covers the testis and gives it a smooth surface, in the same manner as it envelopes the other loose abdominal viscera. " The epididymis lies along the outside of the posterior edge of the testis, as when in the scrotum, but is larger in proportion, and adheres backwards to the psoas. When the foetus is very young, the adhesion of the testis and epididymis to the psoas is very narrow, and then the testis is more loose, and more projecting; but as the foetus advances in months, the adhesion of the testis to the psoas becomes broader and tighter. " The vessels of the testis, like those of most parts of the body, commonly rise from the nearest larger trunks, viz., from the aorta and cava, or from the emulgents. " The artery generally rises from the fore part of the aorta, a little below the'emulgent artery, and often from the emulgent itself, especially in the right side of the body, which may happen the rather, because the trunk of the aorta is more distant from the right testis than from the left. Sometimes, but much more rarely, the spermatic artery springs from the phrenic, or from that of the capsula renalis. Besides the artery which rises from the aorta, or emulo-ent, &c, the testis receives one from the hypogastric artery, which is sometimes as large as the other. It runs upwards from its origin, passing close tothe vas deferens in its way to the testis. The superior spermatic artery sometimes passes before the lower end of the kidney; and both these arteries run in a serpentine direction, making pretty large but gentle turnings. They are situ- 44 HUNTER ON THE ANIMAL 03CONOMY. ated behind the peritoneum, and both run into the posterior edge of the testis, between the two reflected laminae of that membrane, much in the same manner as the vessels pass to the intestines between the two reflected lamina) of the mesocolon or mesentery. " The veins of the testis are analogous to its arteries, but commonly change sides with the arteries respecting their origins from the emulgents. The superior spermatic vein, to begin with its trunk, rises commonly in the following manner: on the right side, from the trunk of the vena cava, a little below the emulgent; and on the left side, from the left emulgent vein. The reason of this difference between the right and left spermatic vein, no doubt, is because the cava is not placed in the middle of the body; so that by the rule of ramification which is observed in most parts of the body, the cava is the nearest large vein of the right side, and the emulgent is the nearest large vein of the left side. But the difference is inconsiderable; and accordingly we sometimes find the right spermatic vein coming from the right emulgent vein; and several other varieties are produced, which so far as I can observe, follow no precise rule. There is likewise a spermatic vein, which rises from the internal iliac, and runs up to the testis with the inferior spermatic artery. Both the spermatic veins run behind the peritoneum with their corresponding arteries, and go into the posterior edge of the testis, where they are lost in small branches. " The nerves of the testis, like its blood-vessels, come from the nearest source; that is, from the abdominal plexuses of the intercostal, especially the inferior mesenteric plexus. They run to the testis, accompanying its blood-vessels, and are dispersed with them through its substance. The testis, therefore, with respect to its nerves, may be reckoned an abdominal viscus ; and this observation will hold good when applied to the full-grown subject; as well as to the foetus ; for those branches of the lumbar nerves which are commonly said to be sent to the testis, passing through the tendon of the external oblique muscle, in reality go not to the testis itself, but to its exterior coverings, and to the scrotum." p. 75. The testicle receiving its nerves from the plexuses of the intercostal, accounts for the stomach and intestines sympathizing so readily with it and its particular sensation, and for the effects arising in the constitution upon its being injured. " The epididymis begins at the outer and posterior part of the upper end of the testis, immediately above the entrance of the bloodvessels, where it is thick, round, and united to the testis. As it passes down it becomes a little smaller and more flat, and is only attached backwards to the testis, or rather indeed to its vessels; for its anterior edge lies loose against the side of the testis forwards; and at its lower end it is again more firmly attached to the body of the testis, so that in the foetus there is a cavity or pouch formed between the middle part of the testis and the middle part of the epididymis, more considerable than is commonly observed in full-grown subjects. As the body grows, the epididymis adheres moire closely to SITUATION OF THE TESTIS IN THE F03TU8. 45

the side of the testis; and its greatest part is made up of one convoluted canal, which becomes larger in size and less convoluted towards the lower end, and at last is manifestly a single tube running a little serpentine. That change happens at the lower end of the testis, and there the canal takes the name of vas deferens. " The vas deferens is a little convoluted or serpentine in its whole course, but is less so as it comes nearer to the bladder; instead of running upwards from the lower end of the testis, as it does when the testicle is in the scrotum, while that remains in the abdomen, it runs downwards and inwards in its whole course, so that it goes on almost in the direction of the epididymis, of which it is a continuation. It turns inwards from the lower end of the epididymis, under the lower end of the testis, and behind the upper end of a ligament or gubernaculum testis (which I shall presently describe); then it passes over the iliac vessels, and over the inside of the psoas muscle, somewhat higher than in adult bodies, and at last goes between the ureter and bladder towards the basis of the prostate gland." p. 77. In those animals where the testicles change their situation the cremaster muscle, which should be named musculus testis, has two very different positions in the foetus and in the adult, the first being the same as in those animals whose testicles remain through life in the cavity of the abdomen; we must therefore conclude that the same purposes are answered by this muscle in the foetus as in those animals. The use of this muscle, when the testicle is in the scrotum, appears to be evidently that of a suspensory; for I find this muscle is strong in proportion to the size of the testicle and pendulous situation in other animals. But what purpose it answers in the foetus, or in animals whose testicles remain in the abdomen, is not easily imagined, there being no apparent reason why such a muscle should exist.* The cremaster, or musculus testis, appears to be composed of the lower fibres of the obliquus internus and transversalis muscles'in the foetus, turning upwards, and spreading upon the anterior surface of the gubernaculum, immediately under the peritoneum; it appears to be lost on the peritoneum, a little way from the testicle. This, although now inverted, is more evidently seen in adult subjects who have had a hydrocele or rupture; in such cases the muscle becomes stronger than usual, and its fibres can be traced spreading on the tunica vaginalis, and seem at last to be lost upon it, near to the lower end of the body of the testicle. The nerves which supply this muscle are probably branches from

* [The cremaster does not in fact exist i n the true testiconda, as the elephant, hyrax, seal walrus, the Cetaceous and Monotrematous Mammalia; in these the testes are merely supported by their vessels and a fold of peritoneum analogous to the broad ligaments of the uterus and ovaries ; but when the cremaster is met with in apparent testiconda it is always in relation to a partial or temporary escape of the testis from the abdomen, as in bats and most insectivorous Ferse, and in many of the Glires, as the rats, squirrels, beaver, porcupine, &c] 46 HUNTER ON THE ANIMAL CECONOMY. the nerves of the obliquus internus and transversals muscles ;* for the same cause which throws the abdominal muscles into action produces a similar effect on the musculus testis; which circumstance appears to be most remarkable in the young subject. When we cough or act with the abdominal muscles, we find the testicles to be drawn up; the musculus testis and abdominal muscles taking on the same action from the same cause.f " At this time of life the testis is connected in a very particular manner with the parietes of the abdomen, at that place where in adult bodies the spermatic vessels pass out, and likewise with the scrotum. This connexion is by means of a substance which runs down from the lower end of the testis to the scrotum, and which at present I shall call the ligament, or gubernaculum testis, because it connects the testis with the scrotum, and seems to direct its course through the rings of the abdominal muscles. It is of a pyramidal form ; its large bulbous head is upwards, and fixed to the lower end of the testis and epididymis, and its lower and slender extremity is lost in the cellular membrane of the scrotum. The upper part of this ligament is within the abdomen, before the psoas, reaching from the testis to the groin, or to where the testicle is to pass out of the abdomen ; whence the ligament runs down into the scrotum, precisely in the same manner as the spermatic vessels pass down in adult bodies, and is there lost. The lower part of the round ligament of the uterus in a foetus very much resembles this ligament of the testis, and may be plainly traced down into the labium, where it is imperceptibly lost. That part of the ligamentum testis which is within the abdomen is covered by the peritoneum all round except at its posterior part, which is contiguous to the psoas, and connected with it by the reflected peritoneum and by the cellular membrane. It is hard to say what is the structure or composition of this ligament; it is certainly vascular and fibrous, and the fibres run in the direction of the ligament itself, which is covered by the fibres of the cremaster or musculus testis, placed immediately behind the peritoneum. This circumstance is not easily ascertained in the human subject; but is very evident in other animals, more especially in those whose testicles remain in the cavity of the abdomen after the animal is full grown. " In the hedgehog the testis continue through life to be lodged within the abdomen, in the same situation as in the human foetus;

* [The first lumbar nerve, which gives many small branches to the transversalis abdominis, sends off a branch which, in conjunction with smaller branches from the second lumbar nerve, forms the'external spermatic nerve' from which the cremaster is supplied.] f [As the cremaster is supplied from common or spinal nerves, it is not surprising that it should in some cases, like the occipito-frontalis muscle, be under the control of the will. Mr. Marshall observes, in his work On Recruits, " Some individuals have the voluntary power of contracting and relaxing the cremaster muscle : others can elevate the testicle on one side but not on the other; and 1 have seen a few persons who could voluntarily raise a testicle, but had not the power of letting it return into the scrotum."] SITUATION OF THE TESTIS IN THE FOJTUS. 47 and they are fastened by the same kind of ligament to the inside of the parietes of the abdomen at the groin. Now in that animal I find that the lowermost fibres of the internal oblique muscle, which constitute the cremaster, are turned inwards at the place where the spermatic vessels come out in other animals, making a smooth edge or lip by their inversion, and that then they mount up on the ligament to the lower end of the testis.* Sometimes in the human body, and in many other animals, and very often in sheep, the testes do not descend from the cavity of the abdomen till late in life, or never at all. In the ram, when the testis is come down into the scrotum, the cremaster is a very strong muscle; and, though it be placed more inwards at its beginning, it passes down pretty much as it does in the human body, and is lost on the outside of the tunica vaginalis; but in the ram, whose testis still remains suspended in the abdominal cavity, I find that the cremaster still exists, though it is a weaker muscle; and instead of passing downwards, as in the former case, it turns inwards and upwards, and is lost in the peritoneum that covers the ligament which attaches the testis to the parietes of the abdomen, which in this state of the animal is about an inch and a half in length. In the human foetus, while the testis is retained in the cavity of the abdomen, the cremaster is so slender that I cannot trace it to my own satisfaction, either turning up towards the testis or turning down towards the scrotum. Yet, from analogy, we may conclude that it passes up to the testicle; since in the adult we find it inserted or lost on the lower part of the tunica vaginalis, in the same manner as in the adult quadruped.! " The peritoneum, which covers the testis and its ligament or gubernaculum, is firmly united to the surfaces of these two bodies; but all around, to W7it, on the kidney, the psoas, the iliacus, internus, and the lower part of the abdominal muscles, that membrane

* [The apparent anomaly of this, as of almost every other natural structure, disappears when we attain the requisite amount of knowledge respecting the conditions under which it exists. The testes of the hedgehog, like those of the mole, (see p. 66,) are subject to remarkable periodical enlargement at the season of copulation, when they are drawn down by the cremaster 10 the external ring. In this situation they are favourably placed to be affected by the expulsive actions of the diaphragm and abdominal muscles, by which they are eventually protruded and the cremasteric pouch is inverted. As the testes diminish in size their muscular covering contracts upon them and returns them into the abdomen.] f [By such a pre-arrangement of the relations of the cremaster to the testis the necessity for the latter to overcome in its passage outwards the resistance of the inferior fibres of the transversalis abdominis and obliquus internus is obviated. It cannot reasonably be doubted that the cremaster exists, as such, in the human foetus prior to the descent of the testis, since it is indubitably present and attached to an abdominal testis in animals where no mechanical cause could have operated to produce this disposition of the muscular fibres. Besides, the use of the cremaster as a supporter and compressor of the testis is obviously too important for sueh a connexion to have been allowed to result from the gland accidentally, as it were, pushing before it some opposing fibres of the abdominal muscles in its progress outwards, as Carus imagines. See his Comparative Anatomy, by Gore, vol. ii., p. 347.] 48 HUNTER ON THE ANIMAL CECONOMY. adheres very loosely to all the surfaces which it covers. Where the peritoneum is continued or reflected from the abdominal muscles to the ligament of the testis it passes first downwards a little way, as if going out of the abdomen, and then upwards, so as to cover more of the ligament than is within the cavity of the abdomen. At this place the peritoneum is very loose, thin in its substance, and of a tender gelatinous texture; but all around the passage of that ligament the peritoneum is considerably tighter, thicker, and of a more firm texture. When the abdominal muscles are pulled up so as to tighten and stretch the peritoneum this membrane remains loose at the passage of the ligament while it is braced or tight all around; and in that case the tight part forms a kind of border or edge around the loose double part of the peritoneum, where the testis is afterwards to pass. This loose part of the peritoneum, like the introsuscepted gut, may, by drawing the testis upwards, be pulled up into the abdomen, and made tight, and then there is no appearance of an aperture or passage down towards the scrotum ; but when the scrotum and ligament are drawn downwards, the loose doubled part of the peritoneum descends with the ligament, and then there is an aperture from the cavity of the abdomen all around the fore part of the ligament, which seems ready to receive the testis. This aperture becomes larger when the testis descends lower, as if the pyramidal or wedge-like ligament was first drawn down in order not only to direct but to make room for the testis which must follow it. In some foetuses I have found the aperture so large that I could push the testis into it as far as the tendon of the external oblique muscle. " From this original situation within the abdomen the testis afterwards descends to its destined station in the scrotum; but it becomes difficult to ascertain the precise time of this descent, as we hardly ever know the exact age of our subject. According to the observations which I have made, it seems to happen sooner in some instances than in others; but generally about the eighth month. In the seventh month I have commonly found the testis in the abdomen ; and in the ninth I have as commonly found it in the upper part of the scrotum. The descent being thus early, and the passage being almost immediately closed, are the principal means of preventing the hernia congenita. " At the before-mentioned period the testis moves downwards till its lower extremity comes into contact with the lower part of the abdominal parietes: when the upper part of the ligament, which hitherto was within the abdomen, has sunk downwards, it lies in the passage from the abdomen to the scrotum, and in that which is afterwards to receive the testis. As the testicle passes out it in some degree inverts the situation of the ligament passing down beyond it; what was the anterior surface of the ligament while in the abdomen, now becoming posterior and composing the lower and anterior part of the tunica vaginalis, on which the musculus testis is lost. This is more evident in those animals whose testicles SITUATION OF THE TESTIS IN THE FCETUS. 49

can readily be made to pass up from the scrotum to the abdomen. The place where the ligament is most confined, and where the testis meets with most obstruction in its descent, is the ring in the tendon of the external oblique muscle; and accordingly I think we see more men with one testis or both lodged immediately within the tendon of that muscle than who have one or both still included in the cavity of the abdomen, which I shall take notice of hereafter. " After the testis has got quite through the tendon of the external oblique muscle it may be considered as now in a way easily to acquire its determined station, though it commonly remains for some time by the side of the penis,* and only by degrees descends to the bottom of the scrotum ; and when the testis has descended entirely into the scrotum its ligament is still connected with it, and lies immediately under it, but is shortened and compressed. " Having now given an account of the original situation of the testes, of the time of their descent from the abdomen, and of the route which they take in their passage to the scrotum, I shall in the next place describe the manner in which they carry down the peritoneum with them, and then explain how that membrane forms the tunica vaginalis propria in common, and the sac of the hernia congenita in some bodies. " While the testis is descending, and even when it has passed into the scrotum, it is still covered by the peritoneum, exactly in the same manner as when within the abdomen, the spermatic vessels running down behind the peritoneum there as they did when the testis lay before the psoas muscle: that lamella of the peritoneum is united behind with the testis, the epididymis, and the spermatic vessels, as it was in the loins, and likewise with the vas deferens; but the testis is fixed posteriorly to the parts against which it rests, being unconnected and loose forwards, as while it remained in the abdomen. In coming down, the testis brings the peritoneum with it; and the elongation of that membrane, though in some circumstances it be like a common hernial sac, yet in others is very different. If we can imagine a common hernial sac reaching to the bottom of the scrotum, covered by the cremaster muscle ; and that the posterior half of the sac covers and is united with the testis, epididymis, spermatic vessels, and vas deferens; and that the anterior half of the sac lies loose before all those parts, it will give a perfect idea of the state of the peritoneum, and of the testis when it comes first down into the scrotum. The testis therefore, in its descent, does not fall loose, like the intestine or epiploon, into the elongation of the peritoneum, but slides down from the loins, carrying the peritoneum with it; and both that and the peritoneum continue to adhere, by the cellular membrane, to the parts behind them, as they did when in the loins. This is a circumstance which

* [This is the permanent situation of the testis in the Quadrumana, in which also, as in the human foetus at the period above mentioned, the tunica vaginalis communicates with the abdominal cavity.] 6 50 HUNTER ON THE ANIMAL CECONOMY. I think may be easily understood, and yet that does not appear to be the case; for I find students very generally puzzled with it, imagining that when the testis comes first down it should be loose all round, like a piece of the gut or epiploon in a common hernia. The ductility of the peritoneum, and its very loose connexion by a slight cellular membrane to psoas muscle, and all the other parts around the testis, are circumstances which favour its elongation and descent into the scrotum with the testis." " This peculiarity of descent often takes place in some of the intestines ; but can only happen in those which have adhesions to the loins. This I suspect is only to be met with in old ruptures, never happening at the first formation of the hernial sac, in which the intestine lies ; and, I should suppose, could only form very gradually. The caecum has sometimes been found to have descended into the scrotum, and to have brought along with it the adhesions through its whole course. The same thing has happened to the sigmoid flexure of the colon; and I have found the whole of it in the left side of the scrotum, with its adhesions brought down from the loins. Such hernias cannot be reduced; and in case of strangulation, which may be brought on by a fresh portion of intestine coming down, are not to be treated in the common way : the sac should not be opened, but the stricture divided, and the newly protruded part reduced. " It is plain, from this description, that the cavity of the bag, or of the elongation of the peritoneum, which contains the testis in the scrotum, must at first communicate with the general cavity of the abdomen by an aperture at the inside of the groin. That aperture has exactly the appearance of a common hernial sac ; the spermatic vessels and vas deferens lie immediately behind it, and a probe passes readily through it from the general cavity of the abdomen down [to the bottom of the scrotum. And if this process of the peritoneum be laid open through its whole length on the fore part, it will be plainly seen to be a continuation of the peritoneum: the testis and epididymis will appear at the lower part of it, and the spermatic vessels and the vas deferens will be found covered by the posterior part of the bag in their whole course from the groin to the testis. " Thus it is in the human body when the testis is recently come down: and thus it is, and continues to be through life, in every quadruped which I have examined where the testis is in the scrotum; but in the human body the communication between the sac and the cavity of the abdomen is soon cut off. Indeed I believe that the upper part of the sac naturally begins to contract as soon as the testis has passed through the muscles; which opinion is grounded on the following observation. In an instance where, from the age of the foetus and from every other mark, it was probable that the testis was very recently come down, and yet the upper part of the sac was very narrow, I pushed the testis upwards, in order to see if it could be returned. The attachments of the testis easily admitted of its ascent, and so did the aperture in the tendon SITUATION OF THE TESTIS IN THE FCETUS. 51

of the external oblique muscle ; but the orifice and upper end of the sac would not by any means admit of the testis being passed quite up into the abdomen. However this may be, the upper end of the sac certainly contracts and unites first, and is quite closed in a very short space of time, for it is seldom that any aperture remains in a child born at its full time; and this contraction and union is continued downwards till it comes near the testicle, where this disposition does, not exist, leaving the lower part of the sac open or loose through life even in the human subject, and forming the tunica testis vaginalis propria, the common seat of a hydrocele. Many cases of hydrocele in children seem to prove that the progress of this contraction and union is downwards; for in them the water commonly extends higher up the chord than in the adult, except in those of a considerable size; yet in some children this union seems not to take place regularly, being interrupted in the middle, and producing a hydrocele of the chord which neither communicates with the abdomen nor tunica vaginalis testis. The contraction and obliteration of the passage appears to be a peculiar operation of Nature, depending upon steady and uniform principles, and not the consequence of inflammation nor of anything that is accidental; and therefore, if it is not accomplished at the proper time, the difficulty of bringing about a union of the parts is much greater, as is seen in children who have had the sac kept open by a turn of the intestine falling down in the scrotum immediately after the testis. This looks as if Nature, from being balked when she was in the humour to do her work, would not or could not so easily do it afterwards. I shall readily grant that what has been advanced here as a proof of the doctrine may be explained upon other principles ; but this at least is certain, that the closing of the mouth and of the neck of the sac is peculiar to the human species ;* and we must suppose the final intention to be the prevention of ruptures, to which men are so much more liable than beasts from their erect state of body." In some cases the aperture of the sac is not entirely closed, allowing a fluid to pass down and form a hydrocele; which fluid, upon pressure, can be squeezed back into the belly ; and instances of this kind sometimes giving the idea of a gut being protruded, make it difficult to determine the exact nature of the case. " What is the immediate cause of the descent of the testis from

* [The chimpanzee, or African orang-utan (Simia Troglodytes, Blum.), which of all mammalia approximates most closely to the human structure, resembles man in the early obliterations of the canal which leads from the peritoneal cavity to the tunica vaginalis. In the Indian orang (Simia Satyrus, Linn.), on the contrary, the canal of communication is free. This difference of structure relates doubtless to the different conditions of the lower extremities in these otherwise closely allied quadrumana : in the chimpanzee they are proportionally larger and stronger, the leg can be more extended on the thigh, and the hip-joint is strengthened by a ligamentum teres; in the orang, on the contrary, the lower limbs are freely developed as organs of support, but have great extent of motion, the hipjoint being, like the shoulder-joint, without a round ligament.] 52 HUNTER ON THE ANIMAL CECONOMY. the loins to the scrotum? It is evident that it cannot be the compressive force of respiration ; because the testis is commonly in the scrotum before the child has breathed, that is, the effect has been produced before the supposed cause has existed. Is the testis pulled down by the cremaster muscle ? I can hardly suppose that it is ; because, if that was the case, I see no reason why it should not take place in the hedgehog, as well as in other quadrupeds ; and if the musculus testis had this power it could not bring it lower than the ring of the muscle. " Why do the testes take their blood-vessels from such distant trunks ? Those physiologists who have puzzled themselves about the solution of this question have not considered that in the first formation of the body the testes are situated not in the scrotum but immediately below the kidneys; and that therefore it was very natural that their blood-vessels should rise nearly in the same manner as those of the kidneys, but a little lower.* The great length of the spermatic vessels in the adult body will no doubt occasion a more languid circulation, which we may suppose was the intention of nature. " The situation of the testis in the foetus may likewise account for the contrary directions of the epididymis and of the vas deferens in adult bodies, though these two in reality make only one excretory canal. In the foetus the epididymis begins at the upper end of the testis; and it is natural, considering it is an excretory tube, that it should run downwards. And it is as natural that the rest of the tube, which is called vas deferens, should turn inwards at the lower end of the testis, because that is its most direct course to the neck of the bladder. Thus we see that in the foetus the excretory duct is always passing downwards. But the testis is directed in its descent by the gubernaculum, which is firmly fixed to the lower parts of the testis and epididymis, and to the beginning of

* [The singular course of the recurrent nerves results from a similar mechanical cause. At the period when the rudimentary larynx first derives its nerves from the par vagum, the head and trunk are not separated by a neck, the trachea is not formed, the heart is situated near the base of the cranium, and the branchial arteries given off from the bulb of the then single artery pass above the nerves in question. As the anterior extremities bud forth, the brachial plexuses are developed and the neck begins to elongate; then the rings of the trachea are successively added, and the larynx, which before was close to the heart, is carried upward, and the recurrent nerves, restrained by their relations to the arteries, which are now converted into the subclavian on the riaht side, and aortic arch on the left, become proportionately elongated. The recurrent course of the branch 6f the dental nerve which supplies the pulp of the incisor in the porcupine and other Rodentia is explicable on a similar principle, the relative position of the pulp to the origin of its nerve being gradually changed by the growth of the jaw and extension of the tooth See the preparation illustrating this fact in the ballery of the Hunterian Museum, No. 357 b. It is scarcely necessary to observe that the above mechanical explanation of the course of the recurrent nerves leaves the question of the final cause as open as before. Mr. Hunter, after giving the physical cause of the course of the spermatic artery, next proceeds to inquire into the intention of Nature with reference to that peculiarity.] SITUATION OF THE TESTIS IN THE FCETUS. 53

the vas deferens, and thence must keep those parts invariably in their situation with respect to one another: and therefore in proportion as the testis descends the vas deferens must ascend from the lower end of the testis; and it must, from the passage through the abdominal muscles down to the testis, run parallel with the spermatic vessels. " The testis, its coats, and the spermatic chord are so often concerned in some of the most important diseases and operations of surgery, particularly in the bubonocele and hydrocele, that their structure has been examined and described by the surgeons, as well as by the anatomists, of every age. Yet the descriptions of the clearest and best writers upon the subject differ so much from one another, and many of them differ so much from what is obvious and demonstrable by dissection, as to render it difficult to account for such a variety of opinions. The very different state of the parts in the quadruped and in the human body, no doubt, must have occasioned error and confusion among the writers of more ancient times, when the parts of the human body were described from dissections and observations made principally upon brutes: and the structure of parts, which are peculiar to the foetus, having been imperfectly understood, we may suppose, has likewise contributed to cause perplexity and contradiction among authors. " Baron Haller, in his Opuscula Pathologica, has observed that in infants the intestine sometimes falls down into the scrotum after the testis, or along with it, and occasions what he calls the hernia congenita. In such a case the hernial sac is formed bofore the intestine falls down, as that ingenious anatomist has observed. There are, besides, two circumstances peculiar to a rupture of this kind, the intestine being always in immediate contact with the testis, and there being no tunica vaginalis propria testis. The structure of the parts in a foetus explains in the most satisfactory manner both these circumstances, however extraordinary they must appear to a man who has only been accustomed to view the parts in subjects of a more advanced age; and indeed it is so clear that it needs no illustration. It should be observed, however, that the hernia congenita may happen not only by the intestine falling down to the testis before the aperture of the sac be shut up, but perhaps afterwards; for when the sac has been but recently closed it seems possible enough that violence may open it again. " It must likewise be obvious to every anatomist, who examines the state of the testis in children of different ages, that the mouth and neck only of the sac close up, and that the lower part of the sac remains loose around the testis, and makes the tunica vaginalis propria. Whence it is plain that this tunic was originally a part of the elongated peritoneum; and, as it is undoubtedly the seat of the true hydrocele, it is also plain that the hernia congenita and the true hydrocele cannot exist together in the same side of the scrotum. For when there is a hernia congenita there is no other cavity than 51 HUNTER ON THE ANIMAL CECONOMY. that of the hernial sac ; and that cavity communicates with the general cavity of the abdomen. " The observations contained in the two last paragraphs occurred to my brother upon reading Baron Haller's Opuscula Pathologica, and gave rise to my inquiries upon this subject."—Medical Commentaries, part i., p. 83. Having explained the situation of the testicles in the foetus, and their descent, with the circumstances attending it, I shall next consider the cases in which the change takes place, in one or both testicles, later than the usual or natural time. And.having remarked the consequences of this descent at so late a period, I shall take notice of those instances in which the testicles never pass out of the abdomen. I have said that the early descent of the testicles, and closing of the mouth of the sac, by usually happening before birth, prevent likewise the descent of any part of the abdominal viscera; but when the testicles remain in their first situation beyond this period these advantages are lost; a part of the intestines or epiploon being, under these circumstances, liable to descend along with them. The first or natural process, in some instances, not having been begun, or having been interrupted before birth, it becomes afterwards very uncertain when the descent will be completed: yet I think the completion most frequently happens between the years of two and ten, while the person is young and growing, being seldom delayed beyond the age of puberty. It is not easy to ascertain the cause of this failure in the descent of the testicle; but I am inclined to suspect that the fault originates in the testicles themselves. This however is certain, that the testicle which has completed its descent is the largest, which is more evident in the quadruped than in the human subject; as in these we can have an opportunity of examining the parts when we please, and can determine how small in comparison with the other that testicle is which has exceeded the usual time of coming down; it never descends so low as the other. The descent of that testicle is very slow which is not completed before birth, often requiring years for that purpose; and it sometimes never reaches the scrotum, especially the lower part of it. There is oftener I believe an inequality in the situation of the two testicles than is commonly imagined, being seldom equally low in - the scrotum; and I am of opinion that the lowest is the most vigorous, having taken the lead readily, and come to its place at once. The part where it meets with the greatest difficulty in its descent is in the division of the tendon of the external oblique muscle called the ring. How far an erect position of body, the action of the abdominal muscles, and the effect produced upon the contents of the abdomen in breathing may contribute mechanically to the descent of the testicles when the natural operations of the animal oeconomy have SITUATION OF THE TESTIS IN THE FCETUS. 55 failed, I will not pretend to decide; but when we see these combined actions producing an unnatural descent of a portion of intestine, we may conceive that they are likewise capable of contributing to the descent of the testicle. When the testicle has remained in the cavity of the abdomen beyond the usual time, it is impossible to say whether the disposition for closing up the passage, after it has passed out, is in any degree lost or not; but when it comes down after birth, we can easily suppose a portion of intestine or epiploon is more likely to descend and prevent the closing of the mouth of the sac, than before the child was born, when certain actions had not taken place. We should therefore watch this descent of the testicle, and endeavour, by art, to procure that union which the natural powers are either not disposed to perform, or are prevented from completing by the descent of other parts; but art should not be used too soon, nor till the testicle has got a little way below the ring. As this progress is very slow, especially when the testicle is creeping through the ring, a doubt often arises whether it is better entirely to prevent its passage, or to assist it by exercise or other means; and it would certainly be the best practice to assist it, if that could be done effectually and safely. When it has got upon the outside of the tendon it can in general be easily pushed up again into the abdomen; and in these two situations it'will sometimes play backwards and forwards for several years, without ever coming low enough to allow of the use of artificial means to hinder its descent, or to prevent a rupture. In this case it becomes difficult to determine what should be done; but, from what I have seen, I should be inclined to wait the descent, giving it every assistance in my power. Indeed, in all cases I would advise waiting with patience, for in most of those which I have seen, years have elapsed from the first appearance of the testicle under the ring of the abdominal muscle before it has reached that situation in which we may safely apply a truss. I never have perceived that any inconvenience has arisen from waiting, and the danger, if there is any, may be in some degree avoided. I have always recommended moderate, not violent exercise. When the testicle has got some way below the ring, then the case is to be treated as an inguinal hernia, and a truss applied upon the ring; taking care that the testicle is not injured by it: but as this generally happens at too early a period for the patients themselves to be capable of attending to it, the surgeon who is employed should be very attentive, and those in whose immediate care they are, particularly watchful, that no inconvenience is produced by the truss. I have, however, known a rupture happen in a man thirty years old, where the testicle had not even got into the ring. In such a case I think a truss should be immediately applied ; for if it is thought advisable to prevent the testicle from coming down, a truss is equally adapted for that purpose, as for hindering the descent of an intestine where there is an hernial sac. It sometimes happens that one of the testicles remains in the 56 HUNTER ON THE ANIMAL CECONOMY. cavity of the abdomen through life, never acquiring the disposition to change its situation; therefore the person naturally concludes that he has only one testicle; and it can only be known that he had two by an examination of these parts after death; it is, however, possible that in some instances one may be wanting; but, if we are to reason from analogy, we must suppose this to be a very rare case; for it is a very common circumstance, that many quadrupeds have only one testicle in the scrotum ; and in such as are killed for food, and from that circumstance come more particularly under observation, if this peculiarity has been noticed, we in general find the other testicle in the cavity of the abdomen; though in some instances they are both found lying in that cavity. When one or both testicles remain through life in the belly, I believe that they are exceedingly imperfect, and probably incapable of performing their natural functions, and that this imperfection prevents the disposition for descent from taking place. That they are more defective than even those which are late in passing to the scrotum, is to be inferred from what is very evident in quadrupeds, the testicle that has reached the scrotum being in them considerably larger than the one which remains in the abdomen. It is probable that this peculiarity is a step towards the hermaphrodite, the testicle being seldom well formed. I have only seen one case in the human subject where both testicles continued in the abdomen; this proved an exception to the above observation, since we are led to conclude that they were perfectly formed, as the persons had all the powers and passions of a man.* In such cases nothing is to be done by art, as it is not possible to give the testicles the stimulus of perfection, which I believe is necessary to make them assume the disposition requisite for their descent ;f and the ring of the external oblique muscle is perhaps less liable, in such instances, to allow a portion of intestine to push down, than where the testicles have passed through it; and such persons may probably be more secure from accidents of this kind than if they had been more perfectly formed. The testicle, in changing its situation, does not always preserve a proper course towards the scrotum, there being instances of its

* [It seems remarkable, that with this experience Mr. Hunter should have formed, from inconclusive analogy, and promulgated an opinion tending to occasion so much unhappiness as that which attributes exceeding imperfection, and probable incapacity of performing their natural functions, to testes which in the human subject are retained within the abdomen. That there is nothing in such a situation which necessarily tends to impair their efficiency, is evident, from the number of animals in which they constantly form part of the abdominal viscera. And in those in which the testes naturally pass into a scrotum, theit continuance in the abdomen, according to our author's own observation, is accompanied only with a difference of size or shape ; now we may readily suppose that this may influence the quantity, but not necessarily the quality of the secretion.] f [The case described in the paper on the vesiculae seminales, p. 61, seems to offer an exception to this rule; the right testicle had passed through the external ring, although the vas deferens was impervious.] SITUATION OF THE TESTIS IN THE FCETUS. 57

taking another direction, and descending into the perinaeum. How this is brought about is difficult to say; it may possibly be occasioned by something unusual in the construction of the scrotum ; or, more probably, by a peculiarity in that of the perinaeum itself; for it is not easy to imagine how the testicle could make its way to the parts about the perinaeum if these were in a perfectly natural state. The first instance of this kind that occurred to me was the child of a shopkeeper in Oxford-street, which I visited, in company with Dr. Garthshore, about the year 1775; but what became of the patient afterwards I do not know. I have lately been consulted in a similar case, by Mr. Hunt, a surgeon, at Burford in Oxfordshire, whose apprehensions of what may be the consequences of a testicle remaining in the perinaeum appear to be well founded. The most effectual method of obviating these will probably be to support the testicle in a situation near the groin, by the application of a bandage that may hinder its descent into the perinaeum, by which the parts may be in time so consolidated as to retain it by the side of the scrotum.

" Dear Sir, " I take the liberty of writing to you, in consequence of having met with a lusus naturae of a peculiar kind, in the son of a man in this neighbourhood. " The boy is about twelve months old: his right testicle is situated about an inch below the termination of the scrotum, and half an inch on the right side of the centre of the rapha perinaei. where a kind of pouch is formed of the common integuments, without the least rugous or scrotal appearance on its surface. It is perfectly detached from the scrotum ; nor can the testis or spermatic process be at any time felt in any part of the scrotum, though I can readily make the testis pass from its situation quite up into the groin ; but immediately upon removing my hand tbe testis falls down into its pouch; and I can trace the spermatic chord from the body of the testis up to the ring, running about a fourth of an inch on the right side of the scrotum. The scrotum on each side appears perfectly formed, and the left testis is in situ naturali. Now, sir, as I conceive this peculiar conformation maybe attended with great inconvenience to the child when he comes to ride on horseback, and on many other occasions, I beg leave to request your opinion upon it, with respect to what ought to be done to prevent accidents, which must, if left in its present situation, often occur. " Burford, Oxfordshire. [Signed] Thomas Hunt." 58 HUNTER ON THE ANIMAL CECONOMY. 2. OBSERVATIONS ON THE GLANDS SITUATED BE- TWEEN THE RECTUM AND BLADDER, CALLED VESICULiE SEMINALES.

Those bags, in the male of some animals, which are situated between the bladder and rectum, and commonly called ' vesiculae seminales,' have been considered as reservoirs of the semen secreted by the testicles, in the same manner as the gall-bladder is supposed to be a reservoir of the bile. Physiologists must have been led to form this opinion from observing that in the human subject their ducts communicate with the vasa deferentia before their termination in the urethra. This communication was supposed to allow the semen, when not immediately wanted, to pass into the bags from the vasa deferentia by a species of regurgitation. But more accurate observations respecting their structure and contents in the human subject, and on corresponding parts in other animals supposed to answer a similar purpose, joined to the circumstance of their not being found in every class, induced me to conclude that this opinion was erroneous. To throw as much light upon this subject as possible I made a number of experiments, and availed myself of every opportunity which offered of examining whatever could in any way elucidate the point; and, from what I have been able to collect, I think it will appear that they cannot be considered as reservoirs of the semen. To proceed regularly with my investigation, I shall begin by comparing the contents of these vesiculae with the semen as it is emitted from the penis of a living man. From "which comparison it will appear that the two secretions are very different in their sensible properties of colour and smell; and although the semen which constitutes the first part of the emission is evidently different from the last, yet every part of it is unlike the mucus found in these vesiculae. The semen first discharged from the living body is of a bluish white colour, in consistence like cream, and similar to what is found in the vasa deferentia after death ; while that which follows is somewhat like the common mucus of the nose, but less viscid. The semen becomes more fluid upon exposure to the air, particularly that first thrown out; which is the very reverse of what happens to secretions in general. The smell of the semen is mawkish and unpleasant, exactly resembling that of the farina of the Spanish chestnut ; and to the taste, though at first insipid, it has so much pungency as, after some little time, to stimulate and excite a degree of heat in the mouth. But the fluid contained in these vesicular in a dead body is of a brownish colour, and often varies in consistence in different parts of the bag, as if not well mixed. Its smell does not resemble that of the semen, neither does it become more fluid by being exposed to the air. J GLANDS CALLED VESICULA SEMINALES. 59

It may, however, be answered to this that the contents of the vesiculae are generally found in a putrid state, and have by that means undergone a change in their sensible properties. But the objection is readily obviated by comparing this fluid with that in the vasa deferentia as it comes from the testicles of the same dead body, between which there appears to be no resemblance. To be still more certain of the nature of what these vesiculae contain than was possible from the examination of bodies which had been dead some time, I took an opportunity of opening a man, immediately after his death, who had been killed by a cannon-ball. The fluid in the vesiculae was of a lighter colour than has usually been found in men who have been dead a considerable lime; but it was not by any means like the semen either in colour or smell. In another man who died instantaneously, in consequence of falling from a considerable height, whose body I inspected soon after the accident, the contents of the vesiculae were of a lightish whey colour, having nothing of the smell of semen, and in so fluid a state as to run out on cutting into them. I have likewise examined with attention a mucus which some men discharge upon straining hard while at stool, or after throwing out the last drops of urine, an action which requires a considerable exertion of the parts. This discharge is generally called a seminal weakness, and is I believe commonly supposed to be the semen ;* but in all cases of this kind in which I have been consulted it nearly resembled the contents of the vesiculae in the dead body, though perhaps not quite of so deep a colour. 1 endeavoured in vain to persuade a gentleman who had this complaint that the discharge was not seminal, till by examining his own semen and comparing it with that mucus he was convinced of the difference. This gentleman had the power of emitting the semen in the same quantity as usual immediately after the mucus had been discharged, which is a further proof that this fluid is not semen.f In this country eunuchs seldom come under our examination; but wre have sometimes opportunities of opening the bodies of those who have, in consequence of disease or accident, lost one or both testicles; and several subjects of this kind I have inspected after death. Persons who have had one testicle taken away will better illustrate the point in dispute than those who have been deprived of both. For it is to be presumed that such men have afterwards had connexion with women, and consequently had the action of emission, which must have emptied the vesicula of the castrated side, if this had contained semen; and, as it could not be replenished, it should have been found empty after death. We have also in such cases an opportunity of making comparative observations between

* Vide Treatise on the Venereal Disease, edit. 1st and 2d, p. 197. [vol. ii., p. 167 of the present edition.] | The discharge was truly supposed to be the contents of the vesiculae; and, it being imagined that these contained semen, according to this reasoning the discharge must be seminal. 60 HUNTER ON THE ANIMAL CECONOMY. the vesicula of the perfect and that of the imperfect side. In the eunuch such emissions never can happen, for the testicles being gone the natural and leading stimulus is lost; therefore, if in them the vesiculae were found full after death, it might be supposed to be the semen which they had received from the testicles before castration that had remained there from the time of the operation; but castration being, in such cases, usually performed on children, this circumstance should rather be considered as a proof that they secrete their own mucus. Yet it is probable the vesiculae will neither be so large nor so full in eunuchs as in the perfect man; for I am of opinion that they are connected with generation, and that if the constitution is deprived of that power these bags will not grow to the full size. But* where only one testicle is removed its loss does not in the least affect generation, therefore does not produce any change in the vesicula of that side from which the testicle is taken ; because the vesicula does not depend upon the testicle for its secretion, but upon the constitution, and on the person being capable of the act of generation : therefore as one testicle is sufficient to preserve manhood, it is of course capable of keeping up the action of both those glands. A man who had been under my care, in St. George's Hospital, for a venereal complaint, died there, and was discovered to have lost his right testicle. From the cicatrix being hardly observable it must have been removed some considerable time before his death; and the complaint for which he was received into the hospital is a convincing proof that he had connexion with women after that period. I inspected the body in the presence of Mr. Hodges, the housesurgeon, and several of the pupils of the hospital. Upon dissecting out and examining the contents of the pelvis, with the penis and scrotum, I found that the vas deferens of the right side was smaller and firmer in its texture than the other, especially at that end next to the abdominal rings, near to the part which had been cut through in the operation. The cellular membrane surrounding the duct, on the right side, was not so loose as on the left; neither were the vessels which ramified on the right vesicula so full of blood. But upon opening the vesiculae, both appeared to be filled with the same kind of mucus, and similar to that which is found in other dead bodies; the vesicula of the right side being rather larger than that on the left. Whatever, therefore, may be the real use of these vesiculae, we have a proof from this dissection that in the human subject they do not contain the semen. In a man who died in St. George's Hospital with a very large bubonocele, the testicle of the diseased side was discovered to have almost lost its natural texture, from the pressure of the hernial sac; and upon examining the testicle with attention there was no appearance of vas deferens till we came near the bladder, where it was almost as large as usual. The vesicula of that side was found to be as full as the other, and to contain the same kind of mucus. GLANDS CALLED VESICULA SEMINALES. 61

I extirpated the left testicle of a Frenchman, who was a married man, and died about a year afterwards, having been extremely il» for several months before his death. On examining the body, the vesiculae were both found nearly full, more especially that on the left side, which might be accidental; but the vas deferens of the left side, where it lies along this bag, and where it has a similar structure with the vesiculae, was likewise filled with the same kind of mucus; which I believe is always the case, whether the testicle has been removed or not. A young man, a coachman, with his left testicle much diseased, had it removed, at St. George's Hospital, by Mr. Walker, in August 1785; and in February 1786 he returned again to the hospital, on account of uncommon pains all over him. For these he requested to be put into the warm bath; but as he was going from the ward for that purpose, he dropped down almost immediately. The body was inspected, with a view to discover the cause of his death ; and, upon examination of the vesiculae, the bag of the left side was as full as that on the right, and ihe contents in both were exactly similar. In the winter 1788 another case occurred nearly resembling the above. In dissecting a male subject, in the year 1755, for a side view of the contents of the pelvis, I found a bag on the left side, lying contiguous to the peritonaeum, just on the side of the pelvis where the internal iliac vessels divide above the angle of reflection of the peritonaeum at the union of the bladder and rectum. The left vas deferens was seen passing on to this bag; and what is very singular, that of the right, or opposite side, crossed the bladder, near its union with the rectum, to join it. I traced the left vas deferens down to the testicle; but, on following the right through the ring of the external oblique muscle, I discovered that it terminated at once, about an inch from its passage out of the abdomen, in a blunt point, which was impervious. On examining the spermatic chord from this point to the testicle, I could not find any vas deferens ; but, by beginning at the testicle, and tracing the epididymis from its origin, about half-way along where it lies upon the body of the testicle, I perceived that it at first became straight, and soon after seemed to terminate in a point. The canal at this part was so largo as to allow of being filled with quicksilver; which, howeier, did not pass far, so that a portion of the epididymis was wanting, and likewise the vas deferens for nearly the whole length of the spermatic chord of the right side. On the left side the vas deferens began where the epididymis commonly terminates, and there was a deficiency of nearly an inch of the extremity of the epididymis. I then dissected the bag above mentioned, which proved to be the two vesiculae; for, by blowing air from one vas deferens, I could only inflate half of it, and from the other vas deferens-the other half. They contained the mucus commonly found in these bags ; but, upon the most accurate examination, I could neither discover 7 62 HUNTER ON THE ANIMAL CECONOMY.

any duct leading from them to the prostate gland, nor the remains

°f iTwas evident in this subject that there was no communication between the vas deferens and epididymis, nor between these bags and the urethra. The caput gallinaginis had the common appearance, but there were no orifices to be found. The testicles were very sound, and the ducts from them to the epididymis were very manifest and contained semen.* # From these circumstances we have a presumptive proof that the semen can be absorbed in the body of the testicle and in the epididymis, and that the vesiculae secrete a mucus which they are capable of absorbing when it cannot be made use of. We may likewise infer from what has been said that the semen is not retained in reservoirs after it is secreted, and kept there till it is used, but that it is secreted at the time in consequence of certain affections of the mind stimulating the testicles to this action; for we find that if lascivious ideas are excited in the mind, and the paroxysm is afterwards prevented from coming on, the testicles become painful and swelled from, we may suppose, the quantity of semen secreted, and the increased action of the vessels, which pain and swelling is removed immediately upon the paroxysm being brought on and the semen evacuated ; but if that does not take place, the action of the vessels will still be kept up, and the pain in the testicle in general continue till the paroxysm and evacuation of the semen is brought on to render the act complete, without which a stop cannot be so quickly put to the action of the vessels that produce the secretion, nor the parts be allowed so easily to resume their natural state. There is at this time no sensation of any kind felt in the seat of the vesiculae seminales, which shows that the action is in the testicles,

* As the semen, in consequence of this preternatural formation of parts, could not be conveyed to the urethra in the usual way, I conceived it possible that there might be another unnatural construction to make up for the deficiency in the vas deferens, and therefore examined it very carefully to see if there were no supernumerary vasa deferentia. I was led to do this more particularly from often finding parts resembling them where they could answer no kind of purpose. By a supernumerary vas deferens I mean a small duct which sometimes arises from the epididymis, and passes up the spermatic chord along with the vas deferens, commonly terminating in a blind end, near to which it is sometimes a little enlarged. I never found this duct go on to the urethra; but, in some instances, have seen it accompany the vas deferens as far as the brim of the pelvis. There is no absolute proof that this is a supernumerary vas deferens; but as we find the ducts of glands in general very subject to singularities, and that there are frequently supernumerary ducts ; that there are often two ureters to one kidney, sometimes distinct from beginning to end; at other times both arising from one pelvis. These ducts, arising from the epididymis, I am inclined from analogy to believe are of a nature similar to the double ureters. They resemble the va3 deferens, as being continuations of some of the tubes of the epididymis; are eonvoluted where they come offfrom it; afterwards become a straight canal, and passing along with it for some way, they are then most commonly "obliterated. The idea of their being for the purpose of returning the superfluous semen to the circulation must certainly be erroneous, from their being so seldom met with, and so very seldom continued further than the brim of the°pelvis. GLANDS CALLED VESICULAE SEMINALES. 63 and in them alone. The pain in the testicles, in consequence of being filled with semen and of the action being incomplete, is sometimes so considerable as to make it necessary to produce an evacuation of the semen to relieve the patient. It may be observed, in support of this opinion, that these bags are as full of mucus in bodies much emaciated, where the person has died from a lingering disease, as in those of the strong and robust, whose death has been occasioned by violence or acute diseases ; and they are nearly as full in the old as in the young; which, most probably, would not be the case if they contained semen. These facts, taken from the human subject, are, I think, sufficient to establish the opinion which I have laid down; but, for the satisfaction of others, I shall give such facts and observations as have occurred in my dissection of different animals as tend to clear up the point in question. These vesiculae are not similar either in shape or contents in any two genera* of animals which I have dissected; and they differ more in size, according to the bulk of the animal, than any other parts whose uses in different animals are supposed to correspond; while the semen in most of those which I have examined may be said to be similar. The resemblance which obtains between these bags and the gallbladder in the human subject by no means holds equally good when applied to other animals. In the horse they are like twof small urinary bladders, almost loose and pendulous, with a partial coat from the peritonaeum, under which there are two layers of muscular fibres; they are thicker in their coats at the fundus than any other part, and appear there to be glandular. Their openings into the urethra are very large, and although they open close to the vasa deferentia do not communicate with them. The septum between the two ducts is not continued on quite to the urethra, so that they cannot, in strict language, be said to enter that passage separately; but there is not length of common duct sufficient to admit of regurgitation from the vasa deferentia into these bags. They are not of the same size in the gelding and in the stone-horse, being large in the last. Their contents in both are exactly similar, and nearly equal in quantity; but in no way resembling the semen emitted by the stone-horse in the coitus, or what is found in the vas deferens after death. In the boar these bags are extremely large, and divided into

* [This term is here used in a more extended sense than in the present systems of natural history; but even as applied to the Linnaean genera the rule is affected by numerous exceptions of which a comparison of the vesiculse seminales of the ape with those of the human subject affords a striking example.] f [There is also in the horse a third vesicula seminalis, of a similar structure to the two lateral ones, between which it is situated, and having, like them, no communication with the vasa deferentia. This want of correspondence therefore between the number of the vesiculae and that of the testes affords another argument against their having the relations to each other which exist between the gall-bladder and liver.] 64 HUNTER ON THE ANIMAL CECONOMY. cells of a considerable size; or they may more properly be said to form ramifications closely connected with one another, and having a large canal or duct common to the whole. The ducts contain a whitish fluid, very unlike what is found in the vasa deferentia of the same animal, with which they have not the least communication.* In the rat the bags are large and flat, with serrated edges, and lie some way within the abdomen, containing a thick ash-coloured mucus, nearly of the consistence of soft cheese; very different from what is found in the vasa deferentia of the same animal, with which they do not communicate. In the beaver the bags are convoluted ; their ducts have no communication with the vasa deferentia, but both the one and the other open on the verumontanum. In the Guinea-pig they are composed of long cylindrical tubes, and lie in the cavity of the belly, are smooth on their external surface, and do not communicate with the vasa deferentia. They contain a thick, bluish, transparent substance, which is softest near the fundus, and becomes firmer towards the openings into the urethra, where it is as solid as common cheese. From this circumstance, and what is observed in the horse, the fundus appears to be the part that secretes this substance, which is very different in colour and consistence from the contents of the vasa deferentia, and is often found in broken pieces in the urethra. To be more certain that the substance contained in these bags was not the secretion of the testicle, I extracted one of the testicles of a Guinea-pig; and six months afterwards gave it the female. As soon as the action of copulation was over (in which all the parts containing semen should naturally have emptied themselves) I killed the animal, and upon examination found the vesicula of the perfect side, and that of the side from which the testicle had been removed, both filled with a substance in every respect similar. It will scarcely be alleged,that this substance had been contained in the bag before the extirpation of the testicle ; nor could it be semen, which must have been all thrown out in the previous connexion with the female. To ascertain that the contents of the vesiculae are not discharged into the vagina of the female with the semen in the act of emission, I killed a female Guinea-pig as soon as the male had left her,

* [Tyson particularly notices the glandular structure of the vesicula? seminales in the peccari and boar, and was led by this circumstance to the same opinion respecting their nature and use as Mr. Hunter is endeavouring to establish by a more extensive and various induction in the present paper. "John van Horn," says Tyson, " would have a threefold matter of the seed : one from the testes, the second from the vesiculae seminales, and a third from the prostates. But this De Graaf strongly opposes; and will admit only that from the testes, which is transmitted to the vesicula; seminales, but not at all bred there. But in our subject, and so m some °ln.ers< they being glandulous, they must therefore secrete some juice; which, in all likelihood, is some way serviceable, though not principally, in veneration. —Anatomy of the Mexico Musk-hog, Phil. Trans., vol. xiii. p. 370, 1683.] GLANDS CALLED VESICULAE SEMINALES. 65 and examined with attention what was contained in the vagina and uterus; in neither could I find any of the mucus of the vesiculae, which from its firmness must have been easily detected. In the hedgehog these bags are very large, being more than twice the size of the vesiculae in the human subject. Many animals have no such bags; and I believe they are wanting in the greater part of that class which Jive chiefly upon animal food ; they are, however, to be found in some of them, and the hedgehog is an example.* There is no apparent difference in the testicles, vasa deferentia, or semen of the animals which have vesiculae and of those which have none ; and the mode of copulation, as far as these bags can be concerned, is very similar in both. In birds, as far as I have yet observed, there is nothing analogous to these bags ; and yet there appears to be no difference between the mode of copulation of the drake and the bull or ram. It is very natural to suppose that if the vesiculae were reservoirs of semen they would be more necessary in birds, who have the power of repeating the act of copulation in an infinitely greater degree than quadrupeds; and indeed we find that in birds there are reservoirs, which may account for this power; the vasa deferentia being enlarged just before they open into the rectum, probably to answer that intention. As birds have no urethra, some having merely a groove, as the drake and gander,f and many being even without a groove, as the common fowl, it was absolutely necessary there should be such a reservoir somewhere; and the necessity of this will appear more evidently by and by. What I have observed of the reservoir of birds is equally applicable to amphibious animals, and to that order of fish called rays. From the above observations I think we may fairly conclude that these vesiculae are not for the purpose of containing semen: the single circumstance of their ducts being united to those of the testicles in the human subject not appearing sufficient to set aside the many facts which are contradictory to such an opinion. Having endeavoured to show that the function of these vesiculae has hitherto been misunderstood, the following observations will tend to prove that they are subservient to generation, though their particular use is not yet discovered ; and, for the better understanding this part of the subject, I shall premise the following facts. "Animals have their natural feelings raised or increased according to the perfection of the parts connected with such feelings ; and the disposition for action is also in proportion to the state of the

* [The vesiculae seminales are wanting in all the Ferae with the exception of the Insectivora ; also in the Ruminants, in the carnivorous Cetacea, and in all the Marsupiata; they are equally wanting in the insectivorous Monotremata, which of all mammilerous animals approximate most closely to the oviparous Vertebrata.] t [After repeated examination, we find the structure of the urethra in the drake to be as here described, viz., a groove, and not a complete canal, as represented by Sir Everard Home. See Phil. Trans. 1802, p. 361, pi. xii.] 7* 66 HUNTER ON THE ANIMAL (ECONOMY. parts and the excitement of such feelings. But, that these feelings may be duly excited, it is necessary that the animal and the parts should be healthv, in good condition, and in a certain degree of warmth suitable to that class to which the animal belongs. In the greatest part of the globe there is a difference in the warmth of the same district at different periods, constituting the seasons; and the cold in some of them is so considerable as to prevent those feelings or dispositions in animals from taking place, and to render them, for the time, unfit for the purposes of generation.* This is owing to the testicles becoming at this season small, and being therefore unfit to give such dispositions, as is the case in. very young animals. This fact is very obvious in birds, of which the sparrow may be produced as a proof. For if a cock-sparrow is killed in the winter, before the days have begun to lengthen, the testicle will be found very small; but if that organ is examined at different times in other sparrows, as the warmth of the weather increases, and if this examination is continued to the breeding-season, the difference in the size of the testicle will be very striking. This circumstance is not peculiar to birds, but is common, as far as I yet know, to all animals which have their seasons of copulation. In the buck we find the testicles are reduced to a very small size in the winter; and in the land-mouse, mole, &c, this diminution is still more remarkable. Animals, on the contrary, which are not in a state of nature have no such change taking place in their testicles; and, not being much affected by seasons, are consequently always in good condition, or in a state to which other animals that are left to themselves can only attain in the warmer season. Therefore in man, who is in the state we have last described, the testicles are nearly of the same size in winter as in summer ; and nearly, though not exactly, the same thing may be observed in the horse, ram, &c, these animals having their seasons in a certain degree. The variation above taken notice of is not confined to the testicles, but also extends to the parts which are connected with them. For in those animals that have their seasons for propagation the most distinctly marked, as the land-mouse, mole, &c, the vesiculae are hardly discernible in the winter, but in the spring are very large, varying in size in a manner similar to the testicle. It may, however, be alleged that the change in these bags might naturally be supposed to take place, even admitting them to be seminal reservoirs; but what happens to the prostate gland, which has never been supposed to contain semen, will take off the force of this objection, since in all the animals which have such a gland (and which have their season for propagation) it undergoes a similar change. In the mole the prostate gland in winter is hardly discernible, but in the spring becomes very large and is filled with mucus.

* It is not required that the season for the copulation of different animals should be equally warm ; for the frog copulates in very cold weather, while the snake and lizard, which are also cold, sleeping animals, do not copulate till the season is warm. GLANDS CALLED VESICULAE SEMINALES. 6"? From these observations it is reasonable to infer that the use of the vesiculae in the animal ceconomy must, in common with many other parts, be dependent upon the testicles. For the penis, urethra, and all the parts connected with them, are so far subservient to the testicles that I am persuaded few of them would have existed if there had been no testicles in the original construction of the body ;* and these would have been so formed as merely to assist in the expulsion of the urine. To illustrate this opinion, let us observe what is the difference between these parts in the perfect male and in a male that has been deprived of the testicles when very young, at an age in which they have had no such influence upon the animal ceconomy as to affect the growth of the other parts. In the perfect male the penis is large; the corpora cavernosaf being capable of dilatation. The corpus spongiosum is very vascular ;J that part of the canal which is called the bulb is considerably enlarged, forming a cavity; and the musculi acceleratores urinae, as they are termed, are strong and healthy. In many animals which have a long penis, the muscular fibres are continued forwards to the end of it; and in others, though not extended so far, they are verylarge. On the contrary, in the castrated animal the penis is small, and not capable of much dilatation ; the corpus spongiosum is less vascular; the cavity at the bulb is a little larger than the canal of the urethra ; and the muscles are white, small, and have a ligamentous

* [The construction and functions of the penis in reptiles and those birds which possess the organ prove the correctness of this view; and very striking evidence of the exclusive relation of the penis to the functions of the testes is afforded by the discoveries in natural history which have been made since the time of Hunter. Thus, in those remarkable Australian quadrupeds, the Omithorhynchus and Echidna, which form the passage from the mammiferous to the oviparous vertebrates, the penis, although perforated through its whole extent, does not carry off the urine, which escapes by the cloaca, but the urethra is destined solely for tne passage of the fecundating fluid during the time of the coitus.] f The cells of the corpora cavernosa are muscular, although no such appearance is to be observed in men ; for the penis in erection is not at all times equally distended. The penis in a cold day is not so large in erection as in a warm one; which, probably, arises from a kind of spasm that could not act upon it if it were not muscular. In the horse the parts composing the cells of the penis appear evidently muscular to the eye; and in a horse just killed they contract upon being stimulated.3 X It may not be improper to observe, that the corpus spongiosum urethra? and glans penis are not sponjjy or cellular, but made up of a plexus of veins. This structure is discernible in the human subject, but much more distinctly seen in many animals, as the horse, &c. a [The disposition of the muscular fasniculi of this part is chiefly longitudinal, interlacing in an undulating manner with the transverse tendinous fibres. They are most numerous near the termination of the corpora cavernosa, and gradually dirriinish as they approach the origin. When examined with a high magnifying power the ultimate fibres of these fasciculi exhibit, but in a fainter degree, the transverse striae characteristic of the voluntary muscular fibre.] 68 HUNTER ON THE ANIMAL CECONOMY. appearance. The same observations are true, if applied to the erectores penis. The penis of the perfect male is of a sufficient length, when erected, to reach to the further end of the vagina of the female. In the castrated animal it is much shorter, and erections having then become unnecessary, the parts which should project often adhere to the inside of the prepuce. The erectores muscles in the perfect male are strong enough to squeeze at once the blood out of the crura into the body of the penis, so as to straighten and contract the urethra instantaneously,' and the acceleratores urinae* have sufficient power to throw out the semen that is gradually accumulated at the bulb for ejection. The prostate gland,f Cowper's glands, and the glands along the urethra (of which the lacunae are the excretory ducts), are in the perfect male large and pulpy, secreting a considerable quantity of slimy mucus, which is salt to the taste; it is most probably for the purpose of lubricating those parts, and is only thrown out when in vigour for copulation : while in the castrated animal these are small, flabby, tough, and ligamentous, and have little secretion. From this account there appears to be an essential difference between the parts connected with generation of the perfect male, and those which remain in one that has been castrated, more especially if that operation had been performed while the animal was young. If it is objected that the same changes did not take place in the men from whom one testicle had been removed, it may be answered, that the operation was performed late in life: and one testicle being left, that was sufficient to carry on the necessary actions, and consequently to preserve the powers; therefore whatever parts

* I shall call these muscles 'expulsores seminis,' as I apprehend their real use to be for the expulsion of that secretion: these muscles, likewise, throw out those drops of urine which are collected in the bulb from the last contractions of the bladder, and they have been, from this circumstance, named acceleratores urinae; but if a receptacle had not been necessary for the semen, those muscles had probably never existed, and the lasj, drops of urine would have been thrown nut by the action of the bladder and urethra, as in some measure is the case in the castrated animal. That the urethra has the power of contraction io evident upon the application of any stimulus, for 1 have seen the urethra refuse to allow an injection to pass on; and in that part where the injection stopped, a fulness was felt, which terminated at once: this contraction is most probably in the internal membrane; it also will often refuse the passage of a boucrje. | The prostate gland is not common to all animals. It is wanting in the bull, buck, and most probably, I believe, in all ruminating animals. In this class the coats of the vesicula; are much thicker and more glandular, than in those which have prostate glands; it is therefore natural to suppose that the vesiculae answer nearly the same purposes as the prostate gland.a The prostate gland, and Cowper's glands, as well as the vesiculae, are wanting in birds, in the amphibious animals, and in those fish which have testicles, as all of the ray kind. a [The glands in Ruminants here termed ' vesicula?,' are now regarded as a bifid prostate.] ° GLANDS CALLED VESICULA SEMINALES. 69 had a connexion with these powers, would still have the stimulus of perfection given to them. The diflerent appearance of the bulb and the muscles would seem to point out, in the perfect male, the enlargement of the bulb to be for the purpose of a receptacle for the semen ; for although I have denied the vesiculae to be reservoirs, yet, as it was necessary that the semen should be accumulated somewhere before ejection, I shall endeavour to prove, from the mode of copulation in the animals we are best acquainted with, that the bulb is intended for that purpose. Let us, therefore, give a short account of the different parts concerned in coition ; and by observing the dependence which they have upon one another, see how this proof will come out. The erection of the penis is produced by a stop being put to the returning blood, and this stoppage is so complete, that no mechanical pressure applied to the body of the penis can force the blood on into the veins. This erection answers two purposes; it gives size and strength to the penis, and it renders the canal of the urethra smaller. The corpus spongiosum of the urethra and the glans, which is only a continuation of it, are filled with blood from the same cause, but not so completely as the body of the penis, since from them it can be forced out into the veins by pressure.* This accumulation of blood in the corpus spongiosum diminishes the canal of the urethra so much, that any pressure upon one part of it will have a considerable effect upon the other; not only by lessening its capacity at the part pressed, but by forcing the blood forward, the parts beyond will be still more distended, and consequently the canal of

* In April 1760, in the presence of Mr. Blount, I laid bare the penis of a dog, almost through its whole length ; traced the two veins that came from the glans (which in this animal makes the largest part of the penis), and separated them from the arteries by dissection, that I might be able to compress them at pleasure without affecting the arteries. 1 then compressed the two veins, and found that the glans and large bulb became full and extended; but when I irritated the veins, in order to see if there was any power of contraction in them which might occasionally stop the return of the blood, no such appearance could be observed.* a [From this experiment, it is obvious that Hunter regarded the stoppage of the circulation through the veins as being produced by external compression. Douglas (Myographies Comparatae Specimen, p. 9), had previously described the muscles which compress the vena dorsalis penis in the dog; and Cowper had more fully and particularly detailed the structure and actions of the muscles which have a corresponding office in the opossum, observing that "the muscles of the cavernous bodies of the penis of this creature, having no connexion with the os pubis, cannot apply the dorsum penis to the last-named bone, and compress the vein of the penis, whereby to retard the refluent blood and cause an erection, as we have observed in other creatures; but some large veins of the penis here take a different course, and pass through the middle parts of the bulb, and are only liable to compression made by the intumescence of the muscles C C (muscles of the bulb) that inclose them. "But the chief agent in continuing the erection of the penis in this animal is the sphincter muscle of its anus, or rather cloaca; and not only the sphincter muscle of the cloaca of the male opossum, but that of the female also closely embraces the penis in coition, and effectually retard the refluent blood from its corpora cavernosa, by compressing the veins of the penis." (Phil. Trans., vol. xxiv. 1704, p. 1581.)] 70 HUNTER ON THE ANIMAL CECONOMY. the urethra be in that proportion diminished. The semen, in the time of copulation, in such animals as remain long in that act, is gradually squeezed along the vasa deferentia (as it is secreted) into the bulb; and when the testicles cease to secrete, the paroxysm, which is to finish the whole operation, comes on. The semen acting as a stimulus to the cavity of the bulb of the urethra, the muscles of that part of the canal are thrown into action; the fibres nearest the bladder, probably, act first, and those more forward in quick succession ; the semen is projected with some force; the blood in the bulb of the urethra is by the same action squeezed forward, but requiring a greater impulse to propel it, is rather later than the semen, on which it presses from behind; the corpus spongiosum being full of blood, acts almost as quick as undulation, in which it is assisted by the corresponding constriction of the urethra, and the semen is hurried along with a considerable velocity.* From the facts which I have stated respecting the organs of generation, the observations which I have made, and the series of actions which I have considered as taking place in the copulation of animals, I think the following inferences may be fairly drawn. That the bags, called vesiculae seminales, are not seminal reservoirs, but glands secreting a peculiar mucus ; and that the bulb of the urethra is, properly speaking, the receptacle in which the semen is accumulated previous to ejection. Although it seems to have been proved that the vesiculae do not contain the semen, I have not been able to ascertain their particular use ; we may, however, be allowed upon the whole to conclude that they are, together with other parts, subservient to the purposes of generation. 3. ACCOUNT OF THE FREE-MARTIN.

Ge.veration, from a seed, requires the concurrence of two causes to give it perfection: the one to form the seed, the other to give it the principle of action.f

* [Besides the functions here assigned to the bulb of the urethra, in relation to the reception and propulsion of the semen, we may also notice its uses in reference to the distention of the glans penis, of which Cowper, in his description of the male organs of the opossum above quoted, gives a remarkable example. He observes : " As the bulb of the urethra in man is framed for the use of the glans, to keep it sufficiently distended when required, so it seems it is necessary to have two of these bulbs inclosed with their particular muscles in this animal, to mainl^L-)rn turgescence of its double or forked glans when the penis is erected." (Phil Jrans., vol. xxiv., 1704, p. 1585.)] f It may be necessary for some of my readers to have explained to them what 1 mean by a seed. I do suppose that the word seed was first applied to grain, or OF THE FREE-MARTIN. 71 The cause forming the seed is called the female, the other the male ; but those two causes in general make only a part of a whole animal, or are rather parts superadded to an animal. Probably these characteristics were first observed in such animals as had the female parts complete in one, and the male in the other ; therefore the teijms female and male have been applied to the whole animal, dividing them into two distinct sexes, and the parts which formed the one sex or the other were called the female or the male parts of generation. But, upon a more accurate knowledge of animals and of their parts of generation, these were found in many of the inferior tribes to be united in the same animal, which from possessing both has got the name of hermaphrodite. As the distinction of male or female parts is natural to most animals, as the union of them in the same animal is also natural to many, and as the separation of them is only a circumstance making no essential difference in the structure of the parts themselves, it becomes no great effort or uncommon play in Nature sometimes to unite them in those animals in which they are commonly separated; a circumstance we really find takes place in many animals of those orders in which such an union is unnatural. From this state of the case hermaphrodites may be divided into two kinds, the natural and unnatural. The natural hermaphrodite belongs to the inferior and more simple genera of animals of which there is a much greater number than of the more perfect; and as animals become more complicated, have more parts, and each part is more confined to its particular use, a separation of the two necessary powers for generation seems also to take place.*

that which is always called seed in the vegetable; which seed is the part of such vegetables in which the matter of the young vegetable exists or is formed. The principle of arrangement in the farina, or male part, fitting the seed for action, being at first not known, a false analogy between the vegetable and animal was established, and the matter secreted by the testes was called the seed ; but, from the knowledge of the distinct sexes in the vegetable, it is well known that the seed is the female production in them, and that the principle of arrangement for action is from the male. The same operation and principles take place in many orders of animals, the female producing a seed in which is the matter fitted for the first arrangement of the organs of the animal, and which receives the principle of arrangement fitting them for action from the male. * [The animals in which the organs of the two sexes are naturally combined in the same individual are confined to the invertebrate division, and are most common in the molluscous and radiate classes. If the term hermaphrodite may be applied to those species which propagate without the concourse of the sexes, but in which no distinct male organ can be detected, as well as to those in which both male and female organs are present in the same body, then there may be distinguished three kinds of hermaphroditism. First, the cryptandrous, or in which the female or productive organs are alone developed. Ex. the accephalous mollusks, as the oyster, lamp-cockle, and ascidia; the cystic entozoa, echinoderms, acalephes, polyps, and sponges. Second, the heautandrous, or in which the male organs are developed, but so disposed as to fecundate the ova of the same individual. Ex. the cirripeds, the rotifers, the trematode and cestoid entozoa. Third, the allotriandrous, or in which the male organs are so disposed as not to 72 HUNTER ON THE ANIMAL C3CONOMY. The unnatural hermaphrodite,* I believe, now and then occurs in every tribe of animals having distinct sexes, but is more in common in some than in others ;f and is to be met with, in all its gradations,

fecundate the ova of the same body, but where the concourse of two individuals is required, notwithstanding the co-existence in each of the organs of the two sexes. Ex. the gastropodous mollusks, with the exception of the peclinibranchiat'e order, the class Annellida. All the other invertebrates, as the cephalopods and pectinibranchiate gastropods, the insects, arachnidans and crustaceans, the epizoa, and the nematoid entozoa, are, like the vertebrate classes, dioecious, or composed of male and female individuals.] * [The unnatural hermaphrodites may be divided into those in which the parts peculiar to the two sexes are blended together in different proportions, and the whole body participates of a neutral character, tending towards the male and female as the respective organs predominate, and into those in which the male and female organs occupy respectively separative halves of the body, and impress on each lateral moiety the characteristics of the sex. This latter and very singular kind of hermaphroditism has hitherto been found only in insects and crustaceans. In the Extracts from the Minute-Book of the Linnean Society, printed in the 14th Vol. of their Transactions, it is stated that Alex. MacLeay, Esq., Sec. L.S., exhibited a curious specimen showing that two Papiliones, referred to distinct families by Fabricius, are in reality the male and female of the same species. This specimen presented the forms and colours of both sexes, divided by a longitudinal line on the body: the right wings and side of the body being as in the male (Papilio Polycaon, Fabr.), and the left as in the female (Papilio Laodocus, Fabr.). In Loudon's Magazine of Natural History, (vol. iv. p. 434,) an experienced entomologist, Mr. J. O. Westwood, has given descriptions and figures, not only of dimidiate hermaphrodites, (the example is the Bombyx Penii) but also of quartered hermaphrodites: the latter singular condition is exemplified in a specimen of the Bombyx castrcnsis, in which the right wing, left antenna, and left side of the abdomen are male; the left wing, right antenna, and right side of the abdomen are female; and again in a specimen of the stag-beetle (Lucanus Cervus), in which the left jaw and right elytrum are masculine, and the right jaw and left elytrum feminine. In most dimidiate hermaphrodites the left side is masculine; but an example of the contrary has been observed in Sphinx Populi. It is to be regretted that the condition of the internal organs of generation cannot be ascertained in the above singular examples; but this deficiency is in some decree supplied by the results of Dr. Nicholl's dissection of a hermaphrodite lobster, (Phil. Trans., xxxvi., p. 290,) in which a testis was found on that side of the body which exhibited externally the male characteristics, and an ovarium on the opposite side.] f Quere: Is there ever, in the genera of animals that are natural hemaphrodites, a separation of the two parts forming distinct sexes? If there is, it may account for the distinction of sexes ever having happened.a a [The separation of the two sexual organs from one another in the same body occurs in many of that class of natural hermaphrodites which we have termed 'allotriandrous;' and there are many examples in the Hunterian collection showing the fact. What, therefore, Mr. Hunter seems here to refer to is a spontaneous fission of the body in the interval separating the two sexual parts, so that one portion of the body shall contain the male and the other the female organs. Some annellides, as the Nais, exhibit the phenomenon of spontaneous fission, but the separation never occurs so as to divide the two sexual organs from one another, and appropriate one to each division; and were even such an occurrence to be supposed ever to take place, the application of the fact to explain the occurrence of the distinct sexes in the naturally dioecious classes seems more worthy of a speculatist of the Lamarckian school than of a sober observer of Nature ] OF THE FREE-MARTIN. 73 from the distinct sex' to the most exact combination of male and female organs. This, I fancy, happens most rarely in the human species, never having seen an instance. I can say the same 01 dogs* and cats, with which last, however, I am less acquainted; but in the horse, ass, sheep, and black cattle it is very frequent. There is one part common to both the male and female organs of generation in all animals which have the sexes distinct: in the one sex it is called the penis, in the other the clitoris; its specific use in both is to continue, by its sensibility, the action excited in coition till the paroxysm alters the sensation. In the female it probably answers no other purpose; but in the male it is more complicated, to adapt it for the purpose of conducting and expelling the semen that has been secreted in consequence of the actions so excited. Though the unnatural hermaphrodite be a mixture of both sexes, and may possess the parts peculiar to each in perfection, yet it cannot possess in perfection that part which is common to both. For as this common part is different in one sex from what it is in the other, and it is impossible for one animal to have bojh a penis and clitoris, the common part must of course partake of both sexes, and consequently render the hermaphrodite so far incomplete ; but these parts peculiar to each sex may be perfectly joined in the same animal, which will convey an idea of the truest hermaphrodite.! Although it may not be necessary, to constitute an hermaphrodite, that the parts peculiar to the one sex should be blended with those of the other, in the same way that the penis is with the clitoris, yet this sometimes takes place in parts whose use in the distinct sexes is somewhat similar, the testicle and ovarium sometimes forming one body, without the properties of either. This compounded part in those animals that have the testicle and ovarium differently situated is generally found in the place allotted for the ovarium; but in such animals as have the testicle and ovarium in the same situation, as the bird tribe, the compound of the two, when it occurs, will also be found in that common situation. The parts of the female appropriated for the purpose of supplying the young with nourishment are variously placed in different animals. In the horse, black cattle, sheep, and other graminivorous animals, their situation is between the hind legs; and this being also the place allotted for the testicles of the male of this tribe, and probably of all those in which the testicles come out of the cavity of the belly; in the hermaphrodite therefore, which has both these

* [For an example of hermaphroditism in a dog, see Phil. Trans., Ixxxix. p. 157.] r~f [In a recent work on hermaphroditism, by Geoffroy St. Hilaire, a mechanical reason is assigned for the non-existence of a penis and clitoris in the same individual, viz., because both parts arise from the same points of the pelvis: but in many animals neither the one nor the other has any bony attachment, and the explanation above given, founded on the similarity of their functions, is more philosophical and satisfactory.] 74 HUNTER ON THE ANIMAL OZCONOMY. parts, the testicles must to a certain degree descend into the udder, though that cannot receive them so readily as the scrotum. The hermaphrodites which I have seen have always appeared externally and at first view to be females, from the penis being the part principally deficient, and there being an opening behind like the bearing in 'the female; and as the testicles in such hermaphrodites seldom come down, the udder is left to occupy its proper place. In animals the female of which is preserved for breeding only, as sheep, goats, pigs, &c, these are generally kept, from their being supposed to be females. Among horses such hermaphrodites are very frequent: I have seen several, but never dissected any. The most complete was one in which the testicles had come down out of the abdomen into the place where the udder should have been (viz., more forward than the scrotum), and, though not so pendulous as the scrotum in the perfect male of such animals, had all the appearance of an udder. There were also two distinct nipples, which, although they exist in the male, have no perfect form, being blended with the sheath or prepuce, of which there was none here. The external female parts were exactly similar to those of the perfect female; but instead of a common-sized clitoris, there was one about five or six inches long, which when erect pointed almost directly backwards. I procured a foal-ass, very similar in external appearance to the horse above-mentioned, and killed it to examine the parts. It had two nipples, but the testicles were not come down as in the above, owing perhaps to the animal's being yet too young. There was no penis passing round the pubis to the belly, as in the perfect male ass. The external female parts were similar to those of the she-ass. Within the entrance of the vagina was placed the clitoris; but much longer than that of a true female, it measuring about five inches. The vagina was pervious a little beyond the opening of the urethra into it, and from thence up to the fundus of the uterus there was no canal. The uterus was hollow at the fundus, or had a cavity in it, and then divided into two horns, which were also pervious. Beyond the termination of the two horns were placed the ovaria as in the true female; but I could not find the Fallopian tubes. From the broad ligaments, to the edges of which the horns of the uterus and ovaria are attached, there passed towards each groin a part similar to the round ligaments in the female, which were continued into the rings of the abdominal muscles ; but with this difference, that there accompanied them a process or theca of the peritoneum, similar to the tunica vaginalis communis in the male ass; and in these thecae were found the testicles, but I could not observe any vasa deferentia passing from them. Here then were found, in the same animal, the parts peculiar to each sex (although very imperfect), and that part which is common to both, but different in each, was a kind of medium of that difference. OF THE FREE-MARTIN. 75 Something similar to the above I have seen in sheep, goats, &c; but I shall not at present trouble the reader with a description ot hermaphrodites in general, as it is a very extensive subject, admitting of great variety, which would make them appear a production of chance ; whereas the intention of this account is to point out a circumstance which takes place in the production of hermaphrodites in black cattle that appears to be almost an established principle in their propagation, and is perhaps peculiar to that, species of animal. It is a fact known, and I believe almost universally understood, that when a cow brings forth two calves, and one of them a bullcalf and the other to appearance a cow, that the cow-calf is unfit for propagation, but the bull-calf grows up into a very proper bull. Such a cow-calf is called in this country a free-martin, and is commonly as well known among the farmers as either cow or bull. Although it will appear, from the description of this animal, that it is an hermaphrodite (being in no respect different from other hermaphrodites), yet I shall retain the term, free-martin, to distinguish the hermaphrodite produced in this way from those which resemble the hermaphrodite of other animals ; for I know that in black cattle such a deviation may be produced without the circumstance of twins : and even where there are twins, the one male the other a female, they may both have the organs of generation perfectly formed. But when I speak of those which are not twins, I shall call them hermaphrodites: the only circumstance worth our notice being a singularity in the mode of production of the free-martin, and its being, as far as I yet know, peculiar to black cattle. This calf has all the external marks of a cow-calf, similar to what was mentioned in the unnatural hermaphrodite, viz., the teats and the external female parts called by farmers the bearing; and when they are preserved by those who know the above fact, it is not for propagation, but for all the purposes of an ox or spayed heifer, viz., to yoke with the oxen and to fatten for the table.* It is known that they do not breed; they do not show the least inclination of the bull, nor does the bull ever take the least notice of them.f They very much resemble, in form, the ox or spayed heifer, being considerably larger than either the bull or the cow, having the horns very similar to the horns of an ox. The bellow of the free-martin is similar to that of an ox, having more resemblance to that of the cow than of the bull. Free-martins are very much disposed to grow fat with good food. The flesh, like that of the ox or spayed heifer, is generally much finer in the fibre than either the bull or cow, is supposed to exceed that of the ox and heifer in delicacy of flavour, and bears a higher price at market.

* I need hardly observe here, that if a cow has twins, and they are both bullcalves, that they are in every respect perfect bulls; or if they are both cow-calves, they are perfect cows. f Vide Leslie on Husbandry, pp. 98, 99. 76 HUNTER ON THE ANIMAL Q2CQNOMY. However, it seems that this is not universal, for I was lately informed by Charles Palmer, Esq., of Luckley in Berkshire, that a free-martin having been killed in his neighbourhood, from the general idea of its being better meat than common, every neighbour bespoke a piece, which turned out nearly as bad as bull-beef; worse, at least, than that of a cow. It is probable that circumstance might arise from this animal having more the properties of a bull than the cow, as we shall see hereafter that they are sometimes more the one than the other.* Although what I have advanced with respect to the production of free-martins be in general true, yet, by the assistance of Benjamin Way, Esq., of Denham, near Uxbridge, who knew my anxiety to ascertain this point, I was lately furnished with an instance which proves that it does not invariably hold good. One of his cows having produced twins, which were to appearance male and female, upon a supposition that the cow-calf was a free-martin, he obligingly offered either to give it me, or to keep it till it grew up, that we might determine the fact: as I conceived it to be a free-martin, and was to have the liberty of examining it after death, I desired that he would keep it; but, unfortunately, it died at about a month old. Upon examining the organs of generation, they appeared to be those of the female, and perfectly formed ; but to make this more certain, I procured those of a common cow-calf, and comparing them together, found them exactly alike. This made us regret that the animal had not lived to an age that might have determined if it was capable of breeding; for the construction of the parts being to appearance perfect, is not sufficient of itself to stamp it a true or perfect female: as I can suppose that the parts being perfectly formed, but without the power of propagation, may constitute the most simple kind of hermaphrodite. It is, however, most probable that this was a perfect female, which is an exception to the common rule; and I have been informed there are instances of such twins breeding.f If there are such deviations, as of twins being perfect male and female, why should there not be, on the other hand, an hermaphrodite produced singly, as in other animals 1 I had the examination of one which seemed, upon the

* The Romans called the bull, taurus; they, however, talked of taurae in the feminine gender. And Stephen observes, that it was thought the Romans meant by taurae, barren cows, and called them by this name because they did not conceive. He also quotes a passage from Columella, lib. vi. cap. 22, "and like the turae, which occupy the place of fertile cows, should be rejected, or sent away." He likewise quotes Varro, De Re Rustica, lib. ii. cap. 5, "The cow which is barren is called taura." From which we may reasonably conjecture that the Romans had not the idea of the circumstances of their production. f [An instance of this nature is recorded in the fifth volume of Loudon's Magazine of Natural History, p. 765. "Jos. Holroyd, Esq., of Withers, near Leeds, had a cow which calved twins, a bull-calf and a cow-calf. As popular opinion was against the cow-calf breeding, it had been considered a free-martin, Mr. Holroyd was determined to make an experiment of them, and reared them together. They copulated, and in due time the heifer brought forth a bull-calf, and she regularly had calves for six or seven years afterwards."] OF THE FREE-MARTIN. 77 strictest inquiry, 1o have been a single calf; and I am the more inclined to think this true, from having found a number of hermaphrodites among black cattle, without the circumstances of their birth being ascertained. Hermaphrodites are to be met with in sheep; but, from the account given of them, I should suppose that they are not freemartins. I have seen several which were supposed to be hermaphrodites, but which were imperfect males, having the penis terminating in the perinaeum, the orifice of which appeared like the bearing in the female. Such are not naturally stimulated to put themselves in the position of the female when they void their urine, so that when it passes the surrounding parts are wetted by it, and being covered with wool, and retaining the urine, keeps them continually moist, and gives the animal a strong smell. They are mentioned as both male and female. I believe it had never been even conjectured, notwithstanding all these peculiarities, what was the true nature of the free-martin; and from the singularity of the animal, and the account of its production, I was almost tempted to suppose the whole a vulgar error. Yet by the universality of the testimony in its favour, it appearing to have some foundation, I eagerly sought for an opportunity to see and examine them. I have succeeded in this inquiry, and have seen several, the first of which was one belonging to John Arbuthnot, Esq., of Mitcham, and was calved in his own farm. He was so obliging as to allow me to satisfy myself, first by permitting a drawing to be made of the animal while alive, which was executed by Mr. Gilpin, and afterwards to examine the parts when the animal died. At the time the drawing was made of Mr. Arbuthnot's freemartin, John Wells, Esq., of Bickley Farm, near Bromley in Kent, was present, and informed us that a cow of his had calved two calves, one of which was a bull-calf, and the other a cow-calf. I desired Mr. Arbuthnot to request Mr. Wells to keep them, or let me buy them of him; but from his great desire of natural knowledge, he very readily consented to preserve both till the bull showed all the signs of a good bull; and when the free-martin was killed, he allowed me to inspect the parts. Of all the specimens which I have dissected, I shall only give the descriptions of the three which point out most distinctly the complete free-martin with the gradations towards the male and female. THE DESCRIPTION OF THE THREE FREE-MARTINS.

Mr. Wright's Free-Martin, five years old.

This animal had more the appearance and general character of the ox, or spayed heifer, than of either the bull or cow. The vagina terminated in a blind end, a little way beyond the opening 8* 78 HUNTER ON THE ANIMAL 03CONOMY. of the urethra, from which the vagina and uterus were impervious. The uterus, at its extreme part, divided into two horns. At the termination of the horns were placed the testicles, instead of the ovaria, as is the case in the female. The reasons why I call these bodies testicles, are the following. First, they were above twenty times larger than the ovaria of the cow, and nearly the size of the testicles of the bull, or rather of those of the ridgil, the bull whose testicles never come down. Secondl}', the spermatic arteries were similar to those of the bull, especially of the ridgil. Thirdly, the cremaster muscle passed up from the rings of the abdominal muscles to the testicles, as it does in the ridgil.* There were the two bags placed behind, between the bladder and the uterus. Their ducts opened into the vagina, a very little way beyond the opening of the urethra; but there was nothing similar to the vasa deferentia. As the external parts had more of the cow than the bull, the clitoris, which may be reckoned an external part, was also similar to that of the cow, not at all in a middle state, between the penis of the bull and the clitoris of the cow, as I have described in the hermaphrodite horse. There were four teats: the glandular part of the udder was but small. This animal cannot be said to have been a mixture of all the parts of both sexes, for the clitoris had nothing similar to the penis in the male, and it was deficient in the female parts, by having nothing similar to the ovaria ; neither had the uterus a cavity.

Mr. Arbuthnot's Free-Martin.^

The external parts were rather smaller than in the cow. The vagina passed on, as in the cow, to the opening of the urethra, and then it began to contract into a small canal, which passed on to the division of the uterus into the two horns, each horn passing along the edge of the broad ligament laterally towards the ovaria. At the termination of these horns were placed both the ovaria and the testicles; they were nearly of the same size, and about as large as a small nutmeg. To the ovariaj I could not find any Fallopian tube. To the testicles were vasa deferentia, but they were imperfect. The left one did not reach near to the testicle ; the right only came

* Although I call these bodies testicles, for the reason given, yet they were only imitations of them, for when cut into they had nothing of the structure of the testicle; not being similar to anything in Nature, they had more the appearance of disease. From the seeming imperfection of the animal itself, it was not to be supposed that they should be testicles; for then the animal should have partaken of the bull, which it certainly did not. f This animal was seven years old ; had been often yoked with the oxen; at other times went with the cows and bull; but never showed any desires for either the one or the other. X [It is probable that these bodies were, as in the case previously noted remains of the corpora Wolffiana.] ' OF AN EXTRAORDINARY PHEASANT. 79 close to it, but did not terminate in a body called the epididymis. They were both pervious, and opened into the vagina near the opening of the urethra. On the posterior surface of the bladder, or between the uterus and bladder, were the two bags, called vesiculas seminales in the male, but much smaller than what they are in the bull; the ducts opened along with the vasa deferentia. This was more entitled to the name of hermaphrodite than the first or third, for it had a mixture of all the parts, though all were imperfect.

Mr. Wells's Free-Martin. This animal was between three and four years old when killed; and had never been observed to show any signs of desire for the male, although it went constantly with one; and looked more like a heifer than free-martins usually do. The teats and udder were small compared with those of a heifer, but rather larger than in either of the former examples; the beginning of the vagina was similar to that of the cow, but soon terminated a little beyond the opening of the urethra, as in the firstdescribed. The vagina and uterus, to external appearance, were continued, although not pervious, and the uterine part divided into two horns, at the end of which were the ovaria. I could not observe in this animal any other body which I could suppose to be the testicle. There was on the side of the uterus an interrupted vas deferens broken off in several places. Behind the bladder, or between that and the vagina, were the bags called vesiculae seminales, between which were the terminations of the two vasa deferentia. The ducts of the bags, and the vasa deferentia, opened as in the last instance. This could not be called an exact mixture of all the parts of both sexes, for here was no appearance of testicles. The female parts were imperfect, and there was the addition of part of the vasa deferentia, and the bags called vesiculae seminales. This circumstance of having no testicles, perhaps, was the reason why it had more the external appearance of a heifer than what they commonly have, and more than either of the two former. 4. AN ACCOUNT OF AN EXTRAORDINARY PHEASANT.

Everv deviation from that original form and structure which gives the distinguishing character to the productions of Nature, may not improperly be called monstrous. According to this 80 HUNTER ON THE ANIMAL CECONOMY. acceptation of the term, the variety of monsters will be almost infinite;* and, as far as my knowledge has extended, there is not a species of animal, nay, there is not a single part of an animal body, which is not subject to an extraordinary formation. Neither does this appear to be a matter of mere chance; for it may be observed that every species has a disposition to deviate from Nature in a manner peculiar to itself.f It is likewise worthy of remark, that each species of animals is disposed to have nearly the same sort of defects, and to have certain supernumerary parts* of the same kind: yet every part is not alike disposed to take on a

* [Mr. Hunter attempted, notwithstanding, to reduce this variety of monsters to definite groups, and left the following outline of a classification of monsters, in an explanatory introduction to the extensive series of those objects in his collection: " 1. Monsters from preternatural situation of parts. " 2.-------------addition of parts. " 3. ---------—- deficiency of parts. " 4.-------------combined addition and deficiency of parts, as in hermaphroditical malformation." Licetus,a Hubert and Malacarnec had proposed classifications of monsters prior to the time of Hunter, all of which are more or less tinctured with the superstitions of the times; thus, the tenth class in the system of Licetus is appropriated to the offspring of the illicit intercourse of demons with women: the fifteenth of Malacarne contains the brutes with human members, &c. Blumenbach, towards the end of the eighteenth century, published an arrangement of monsters which closely resembles that of Hunter; he, however, distinguishes, but without sufficient reason, unnatural hermaphrodites from monsters, and divides the latter into " 1. Monsters by an unnatural conformation of certain parts of the body,— Fabrica aliena. " 2.-----------transposition of parts,—Situs mutatus. " 3.-----------a deficiency of parts,—Monstraper defectum. " 4.-----------supernumerary parts,—Monstra per excessum." The study of the various congenital aberrations from the specific form presented in the different classes of the animal kingdom, has since been ably and successfully pursued by Meckel, Geoffroy St. Hilaire, Otto, Breschet, Charuet, &c, the general results of whose labours may be found in the Histoire Generate et Particu- Uere des Anomalies de V Organization chez f Homme et les Animaux, ou Traite de Teratologic, by Isid. Geoffroy Saint-Hilaire: 8vo, 1832.] f [The value of the principle here enunciated will be appreciated, when it is stated that it is the basis of the latest and most elaborate work on the subject of monsters. It is claimed for Geoffroy St. Hilaire a3 the most important of his deductions in Teratology, and the chief point in which his system differs from, and is superior to, those of his predecessors. " C'est de principes precisement inverses que mon pere a pris sur point de depart; et c'est aussi, comme cela devait etre a des resultats inverses qu'il est parvenu. Etablissant, par un grand nombre de recherches, que les monstres sont, comme les etres dits normaux, soumis a des regies constantes, il est conduit a admettre que la methode de classification que les naturalistes emploient pour les seconds, peut etre appliquee avec succes aux premiers." Isid. Geoffroy St.-Hilaire, loc. cit., p. 99.] 1 Fortunius Licetus, De Monstris, ex recensione G. Blasii: Amstelodami, 1665, 4to. * Observationes nonnullse de Monstris: 4to. Cassel, 1748. c " De' Mostri umani de' Caretteri fondamentali su cui ne se portrebbe stabilire la Classificazione," Mem. delta Soc. Ital., torn. ix. 4. OF AN EXTRAORDINARY PHEASANT. 81 great variety of forms; but each part of each species seems to have its monstrous form originally impressed upon it.* It is well known that many orders of animals have the two parts designed for the purpose of generation different in individuals of the same species, by which they are distinguished into male and female; but this is not the only mark of distinction, in the greatest part the male being distinguished from the female by various other marks. The varieties which are found in the parts of generation themselves I shall call the first or principal marks, being originally formed in them, and belonging equally to both sexes; all others depending upon these I shall call secondary, as not taking place till the first are becoming of use, and being principally, although not entirely, in the male. One of the most general marks is, the superior strength of make in the male ; and another circumstance, perhaps equally so, is this strength being directed to one part more than another, which part is that most immediately employed in fighting. This difference in external form is more particularly remarkable in the animals whose females are of a peaceable nature, as are the greatest number of those which feed on vegetables, and the marks to discriminate the sexes are in them very numerous. The males of almost every class of animals are probably disposed to fight, being, as I have observed, stronger than the females; and in many of these there are parts destined solely for that purpose, as the spurs in the cock, and the horns in the bull; and on that account the strength of the bull lies principally in his neck ; that of the cock in his limbs. In carnivorous animals, whose prey is often of a kind which requires strength to kill, we do not find such a difference in the form of the male and female, very little being discernible in the dog and bitch, in the he or she cat, or in the cock and hen of the eagle.f A difference, however, is often perceivable in the whole or in some part of their external covering; the mane of the lion distinguishing him from the lioness ; and the males of such animals as neither fight nor feed on .flesh, being only distinguishable from the female by some peculiarity in the covering of their bodies, as the cock and hen in many birds. The male of the human species is distinguished

* [In this principle Mr. Hunter is opposed to Geoffroy St.-Hilaire, who attributed the production (Cordonnee) of monstrosities to the operation of exterior or mechanical causes at some period of foetal development. Defective formation in parts of a foetus has indeed been produced by destroying a portion of the respiratory surface of an egg during incubation; but this result by no means affords adequate grounds for assigning as the sole cause of every malformation accidental adhesions between the foetus and its coverings. Mr. Hunter also made experiments with reference to monstrosities, and succeeded in effecting what, at first sight, seems the most difficult to produce, viz., the monsters by excess, of which several specimens of Lacerla, with a double tail (No. 2219—2223), afford examples. It is evident, however, from the expression in the concluding paragraph of the text, that he regarded the cause of congenital malformation as existing in the primordial germ.] | [The difference in the size of the two sexes is sufficiently marked in most of the Raptorial birds; but it is the female which has the advantage in this respect.] 82 HUNTER ON THE ANIMAL C3CONOMY. from the female both by his general strength and his covering, as also by a difference of voice. In these orders of animals whose sexes are distinct, we may not only observe the genital organs to be subject to mal-conformation, as in any other part of the animal, but that an attempt is sometimes made to unite the two organs in the same animal body, making what may be called an unnatural hermaphrodite. In producing the unnatural hermaphrodite the same Jaws seem to operate as in the mal-conformation of other parts of animals; it being observable, that these deviations obtain through a whole species precisely in the same manner. I have already given an account of the free-martin, which exhibits a mixture of the two parts of generation in the same animal. It is my intention at present to extend my inquiry on this subject no further than what relates to the resemblance which one sex bears to another in those distinguishing properties which I term secondary; for we find that there is often a change of the natural properties of the female sex into those of the secondary of the male ; the female, in such cases, now and then assuming the secondary peculiarities of the male. It is to be observed, that some classes are more liable than others to this change, a singular example of which is to be the subject of the following pages. To bring the foregoing observations into one point of view, I here beg leave to remark, that in animals just born, or very young, there are no peculiarities to distinguish one sex from the other, exclusive of what relates to the organs of generation, which can only be in those who have external parts ; and that towards the age of maturity the discriminating changes before mentioned begin to appear; the male then losing that resemblance he had to the female in various secondary properties ;* but that in all animals which are not of any distinct sex, called hermaphrodites, there is no such alteration taking place in their form when they arrive at that age. It is evidently the male which at this time in such respects recedes from the female, every female being at the age of rqaturity more like the young of the same species than the male is observed to be; and if the male is deprived of his testes when young, he retains more of the original youthful form, and therefore more resembles the female. From hence it might be supposed that the female character contains more truly the specific properties of the animal than the male; but the character of every animal is that which is marked by the properties common to bolh sexes, which are found in a natural hermaphrodite, as in a snail, or in animals of neither sex, as the castrated male or spayed female. But where the sexes are separate, and the animals have two

* This is not common to all animals of distinct sexes, for in fishes there is no great difference : nor in many insects ; nor in dogs, as has been already observed: however, it is considerable in many quadrupeds, but appears to be most so in birds. OF AN EXTRAORDINARY PHEASANT. 83 characters, the one cannot more than the other be called the true, as the real distinguishing marks of each particular species, as has been mentioned above, are those common to both sexes, and which are likewise in the unnatural hermaphrodite. That these properties give the distinct character of such animals is evident, for the castrated male and the spayed female have both the same common properties; and when I treated of the free-martin, which is a monstrous hermaphrodite, I observed that it was more like the ox than the cow or bull; so that the marks characteristic of the species which are found in the animal of a double sex are imitated by depriving the individual of certain sexual parts, in consequence of which it retains only the true properties of the species. They are curious facts in'the natural history of animals, that by depriving either sex of the true parts of generation, they shall seem to approach each other in appearances, and acquire a resemblance to the unnatural hermaphrodite. In some species of animals that have the secondary properties we have mentioned, there is a deviation from the general rules, by the perfect female, with respect to the parts of generation, assuming more or less the secondary character of the male. This change does not appear to arise from any action produced at the first formation of the animal, and in this respect is similarto what takes place in the male; neither does it grow up with the animal as it does to a certain degree in the male, but seems to be one of those changes which happen at a particular period, similar to many common and natural phenomena: like to what is observed of the horns of the stag, which differ at different ages; or to the mane of the lion, which does not grow till after his fifth year, &c* This change has been observed in some of the bird tribe, but principally in the common pheasant; and it has been observed by those who are conversant with this bird, when wild, that there every now and then appears a hen pheasant with the feathers of a cock: all, however, that they have described on the subject is, that this animal does not breed, and that its spurs do not grow. Some years ago one of these was sent to the late Dr. William Hunter, which I examined, and found it to have all the parts peculiar to the female of that bird. This specimen is still preserved in Dr. Hunter's museum. Dr. Pitcairn having received a pheasant of this kind from Sir Thomas Harris, showed it as a curiosity to Sir Joseph Banks and Dr. Solander. I happening to be then present, was desired to examine the bird, and the following was the result of my examination. I found the parts of generation to be truly female, they being as

* [We have observed in the young African lions at the Zoological Gardens that the mane began to be distinctly developed at the third year, and was completed at the fourth.] 84 HUNTER ON THE ANIMAL CECONOMY.

perfect as in any hen pheasant that is not in the least prepared for laying eggs, and having both the ovary and oviduct. As°the observations hitherto made have been principally upon birds found wild, little of their history can be known ; but from what took place in a hen pheasant, in the possession of a friend of Sir Joseph Banks, it appears probable that this change of character takes place at an advanced period of the animal's life, and does not grow up with it from the beginning. This lady, who had for some time bred pheasants, and paid particular attention to them, observed that one of the hens, after having produced several broods, moulted, when the succeeding feathers were those of a cock, and that this animal was never afterwards impregnated. Hence it is most probable that all the hen pheasants found wild, having the feathers of a cock, were formerly perfect hens, but have been changed by age, or perhaps by certain constitutional circumstances.* Having bought some pheasants from a dealer in birds, among which were several hens, I perceived, the year after, that one of the hens did not lay, and that she began to change her feathers. The year following she had nearly the plumage of the cock, but less brilliant, especially on the head ; and it is more than probable that this was an old hen, nearly under circumstances similar to to those before described. Lady Tynte had a favourite pied pea-hen which had produced chickens eight several times; having moulted when about eleven years old, the lady and family were astonished by her displaying the feathers peculiar to the other sex, and appeared like a pied peacock. In this process the tail, which became like that of the cock, first made its appearance after moulting ; and in the following year, having moulted again, produced similar feathers. In the third year she did the same, and, in addition, had spurs resembling those of a cock. She never bred after this change in her plumage, and died in the following winter during the hard frost in the year 1775-6. This bird is now preserved in the museum of the late Sir Ashton Lever.f From what has been related of these three birds, we may con-

* [The cause of the change in the plumage which Mr. Hunter here alludes to, has been proved by subsequent dissections to be effective and not uncommon. See the paper entitled ' On the change in the Plumage of some Hen-Pheasants,' by " Wm. Yarrell, Esq., Phil. Trans. 1827, in which the author states, that" certain constitutional circumstances producing this change may, and do occur, at any period during the life of the fowl, and that they can be produced by artificial means."] •f It might be supposed that this bird was really a cock which had been substituted for the hen ; but the following facts put this matter beyond a doubt. First, there was no other pied pea-fowl in the country. Secondly, the hen had nobs on her toes, which were the same after her change. Thirdly, she was. as small after the change as before, therefore too small for a cock. Fourthly, she was a favourite bird, and was generally fed by the lady, and used to come for her food, which she still continued to do after the change in the feathers. OF THE OVARIA. 85 elude, that this change is merely the effect of age, and obtains to a certain degree in every class of animals. We find something similar taking place even in the human species; for that increase of hair observable on the faces of many women in advanced life is an approach towards the beard, which is one of the most distinguishing secondary properties of man. Thus we see the sexes which, at an early period, had little to distinguish them from each other, acquiring about the time of puberty secondary properties, which clearly characterize the male and female, the male at this time receding from the female, and assuming the secondary properties of his sex. The female, at a much later time of life, when the powers of propagation cease, loses many of her peculiar properties, and may be said, except from mere structure of parts, to be of no sex, even receding from the original character of the animal, and approaching, in appearance, towards the male, or perhaps more properly towards the hermaphrodite. 5. AN EXPERIMENT TO DETERMINE THE EFFECT OF EXTIRPATING ONE OVARIUM UPON THE NUMBER OF YOUNG PRODUCED.*

In all animals of distinct sex, the females, those of the Bird-kind excepted, have, I believe, two ovaria, and of course the oviducts are in pairs. By distinct sex I mean when the parts destined to the purposes of generation are of two kinds, each kind appropriated to an individual of each species, distinguished by the appellation of male and female, and equally necessary to the propagation of the animal. The testicles, with their appendages, constitute the male; the ovaria, and their appendages, the female sex. As the ovaria are the organs which, on the part of the female, furnish what is necessary towards the production of the third, or young animal, and as females appear to have a limited portion of the middle stage of life allotted for that purpose, it becomes a question, whether those organs are worn out by repeated acts of propagation ; or whether there is not a natural and constitutional period to that power on their part, even if such power has never been exerted 1 If we consider this subject in every view, taking the human species as an example, we shall discover that circumstances, either local or constitutional, may be capable of extinguishing in the female the faculty of propagation. Thus we may observe when a woman begins to breed at an early period, as at fifteen, and has her children

* [Originally published in the Philosophical Transactions, vol. lxxvii.,p. 233 ; read, March 22, 1787.] 9 86 HUNTER ON THE ANIMAL OZCONOMY.

fast, that she seldom breeds longer than the age of thirty or thirtyfive; therefore we may suppose either that the parts are then worn out, or that the breeding constitution is over. If a v/oman begins later, as at twenty or twenty-five, she may continue to breed to the age of forty or more: and there are, now and then, instances of women who, not having conceived before, have had children as late in life as at fifty years or upwards. After that period few women breed, even though they should not have bred before; therefore there must be a natural period to the power of conception. A similar stop to propagation may likewise take place in other classes of animals, probably in the female of every class, the period varying according to circumstances. But still we are not enabled to determine how far it depends on any particular property of the constitution, or of the ovarium alone. As the female, in most classes of animals, has two ovaria, I imagined that by removing one it might be possible to determine how far their actions were reciprocally influenced by each other, from the changes which by comparison might be observed to take place, either by the breeding-period being shortened, or perhaps, in those animals whose nature it is to bring forth more than one at a time, by the number produced at each birth being diminished. There are two views in which this subject may be considered. The first, that the ovaria, when properly employed, may be bodies determined and unalterable respecting the number of young to be produced. In this case we can readily imagine that, when one ovarium is removed, the other may be capable of producing its determined number in two different ways: one, when the remaining ovarium, not influenced by the loss of the other, will produce its allotted number, and in the same time; the other, when affected by the loss, yet the constitution demanding the same number of young each time of breeding, as if there were still two ovaria; it must furnish double the number it would have been required to supply had both been allowed to remain, but must consequently cease from the performance of its function in half the time. The second view of the subject is, by supposing that there is not originally any fixed number which the ovarium must produce, but that the number is increased or diminished according to circumstances ; that it is rather the constitution at large that determines the number; and that if one ovarium is removed, the other will be called upon by the constitution to perform the operations of both, by which means the animal should produce with one ovarium the same number of young as would have been produced if both had remained. With an intention to ascertain those points as far as 1 could, I was led to make the following experiment; and for that purpose gave pigs a preference to any other animal, as being easily managed, producing several at a litter, and breeding perfectly well under the confinement necessary for experiments. I selected two females of the same colour and size, and likewise a boar-big, all of the same farrow; and, having removed an ovarium from one of OF THE OVARIA. 87 the females, I cut a slit in one ear to distinguish it from the other. They were well fed and kept warm, that there might be no impediment to their breeding; and whenever they farrowed, their pigs were taken away exactly at the same age. About the beginning of the year 1779 they both took the boar ; the one which had been spayed earlier than the perfect female. The distance of time, however, was not great, and they continued breeding at nearly the same times. The spayed animal continued to breed till September 1783, when she was six years old, which was a space of more than four years. In that time she had eight farrows; but did not take the boar afterwards, and had in all seventy-six pigs. The perfect one continued breeding till December 1785, when she was about eight years old, a period of almost six years, in which time she had thirteen farrows, and had in all one hundred and sixty-two pigs; after this time she did not breed: I kept her till November 1786. I have here annexed a table of the different times of each farrow, with the number of pigs produced. Spayed Sow. Farrows. Number cf young. Time. 1 6 Dec. 1779. 2 8 July 1780. 3 6 Jan. 1781. 4 10 Aug. 1781. 5 10 Mar. 1782. 6 9 Sept. 1782. 7 14 May 1783. 8 13 Sept. 1783. 76 November following she was put to the boar, but brought no pigs. April 1784, she was again put to the boar, without effect, and never was observed to take the boar afterwards, although often with him. November 1784, she was killed. Perfect Sow. Farrows. Number of young. Time. 1 9 2 6 3 8 4 13 Dec. 1781. 5 10 June 1782. 6 1'6 Dec. 1782. 7 13 June 1783. 8 12 Oct. 1783. 87 Eleven pigs more than were produced by the spayed sow in her eight farrows. 88 HUNTER ON THE ANIMAL 03CONOMY. Farrows. Number of young. Time. 9 12 Feb. 1784. 10 16 June 1784. 11 12 Dec. 1784. 12 16 May 1785. 13 19 Dec. 1785. 75 h she bred no more. The first eight farrows were ... 87 The last five farrows were . . . .75 Total . 162 The number from the spayed one . . 76

More than farrowed by the imperfect animal . . 86

It is observable that both sows rather increased in their number each time as they grew older, although not uniformly; the difference between the first and last in both animals being considerable. From the above table we find that the sow with only one ovarium bred till she was six years old, from the latter end of 1779 till September 1783, about four years, and in that time brought forth seventy-six pigs. The perfect animal bred till she was eight years of age ; and if conception depended on the ovari, we might have expected that she would bring forth double the number at each birth ; or, if not, that she would continue breeding for double the time. We indeed find her producing ten more than double the number of the imperfect animal, although she had not double the number of farrows; but this may perhaps be explained by observing that the number of young increased as the female grew older, and the perfect sow continued to breed much longer than the other. From a circumstance mentioned in the course of this experiment it appears that the desire for the male continues after the power of breeding is exhausted in the female ; and therefore does not altogether depend on the powers of the ovaria to propagate, although it may probably be influenced by the existence of such parts. If these observations should be considered as depending on a single experiment, from which alone it is not justifiable to draw conclusions, I have only to add that the difference in the number of pigs produced by each was greater than can be justly imputed to accident, and is a circumstance certainly in favour of the universality of the principle I wished to ascertain.* From this experiment it seems most probable that the ovaria are

* It may be thought by some that I should have repeated this experiment; but an annual expense of twenty pounds for ten years, and the necessary attention to make the experiment complete, will be a sufficient reason for my not having done it. DESCRIPTION OF THE UTERUS, ETC. 89 from the beginning destined to produce a fixed number, tyood which they cannot go, although circumstances mav tend to diminish that number; but that the constitution at large has nc.powerfOt giving to one ovarium the power of propagating equal to both, lor in theS present experiment the animal with one ovarium produced ten pigs less than half the number brought forth by the sow with both ovaria. But that the constitution has so far a power of influencing one ovarium as to make it produce its number id a less time than would probably have been the case if both ovaria had been preserved, is to be inferred from the above-recited experiment. r TRF CASE OF A YOUNG WOMAN WHO POISONED HERSELF iN THE FIRST MONTH OF HER PREG- NANCY. BY THOMAS OGLE, SURGEON, GREAT RUSSELL-STREET, BLOOMSBURY.

To which is added, an Account of the Appearances after Death ; by the late John Hunter.*

Mary Hunt, servant to a gentleman in Charlotte-street, Bedfordsquare, twenty-five years of age, had for some time shown a partiality for one of the footmen in the same family. She became all at once exceedingly dejected, which was supposed to proceed irom his neglecting her; and on Thursday, the 19th of April, at twelve o'clock at night, took half an ounce of white arsenic, and immediately afterwards drank a quart of wine; about one o clock she had so much pain in her stomach as to be obliged to call tor assistance. , . , The svmptoms were excruciating pain in the stomach, sickness, vomiting, excessive thirst, and a small tremulous pulse; these were followed by pain in the bowels, and several purging

She drank brandy and water, wine and water, and several quarts of plain water, to relieve the thirst and ease the pain. Some hours after taking the arsenic she became easier, expressed a desire to be left alone, being inclined to sleep, and remained several hours in a dosing or comatose state, from which she did not recover, and died about one o'clock on Friday, thirteen hours after taking the arsenic. . . Upon inspecting the body after death there were found the lollowing appearances.

• [Originally published in the Transactions of a Society for the Improvement of Medical and Chirurgical Knowledge, vol. ii., p. 63. Communicated to the Society by Everard Home, and read August 5, 1794.] 90 HUNTER ON THE ANIMAL G3CONOMY. In the cavity of the abdomen there was an appearance of the effects of slight inflammation on the peritoneal coat of the small intestines. The stomach contained a greenish fluid, with a curdy substance in it, in all amounting to about twelve ounces. On the internal surface of the great curvature near the cardiac a portion of the villous coat, about the size of a crown-piece, was partly destroyed, and of a dark red colour, with a regularly defined edge, and some of the arsenic adhering to different parts of its surface. The rest of the stomach was in a natural state. This appearance in the stomach was an effect produced by the arsenic. The uterus was a little enlarged, and had the vessels unusually loaded with red blood. There was an uncommon quantity of blood in the vessels of the ovaria and Fallopian tubes, but principally in those of the ovarium, and morsus diaboli of the left side. The organs of generation being carefully removed, and both ovaria being slit open, there was found in the left a corpus Iuteum. It was evident, from this circumstance, that conception had taken place ; which led to an inquiry respecting the last appearance of her menses, which appeared by the evidence of the family to have been little more than a month before her death. With the dread upon her mind of being with child, the usual period of menstruation had hardly elapsed without its appearing, which confirmed her suspicions, before she, in a fit of despair, put an end to her life. From this evidence, the period of conception could not exceed a month, and probably was much within that time. As it wras interesting to have the parts accurately examined, to see what information might be acquired respecting the foetus at so early a period, they were given to Mr. Hunter for that purpose, whose observations upon them are contained in the following account. The arteries.of the uterus were injected, and the smaller vessels were filled to so great a degree of minuteness that the whole surface became extremely red. The cervix uteri and os tineas were of their natural size ; but the body, or that portion of the uterus next the fundus, was a little enlarged, and more prominent externally in the middle. The spermatic vessels were also enlarged. On cutting into the substance of the uterus, it had more of a laminated structure than in the unimpregnated state; this appearance of lamellae appeared upon examination to be formed by veins somewhat enlarged, compressed and transversely divided. The uterus was unsually soft in texture, and terminated on the internal surface in a pulpy substance. The blood-vessels of the uterus passed into and ramified upon this pulpy substance, which was continued across at the cervix DESCRIPTION OF THE UTERUS, ETC. 91

uteri, so as to make the cavity of the uterus a circumscribed bag ; and at this part the pulpy substance was so thin as to resemble the retina. This cavity had a smooth but irregular internal surface, and the pulpy substance upon which it was formed was evidently blood coagulated and varied in its thickness in different parts. Upon a longitudinal section of the uterus, the posterior part of the coagulum, which was the thickest, was nearly half an inch; where it terminated towards the cervix it was pendulous and unattached. There were also several loose processes, all turned towards the cervix, one of them very thin, as broad as a silver penny, and only attached by one edge to the fundus near the opening of the right Fallopian tube. On slitting open the Fallopian tubes, the coagulum was found to pass some way into them, and to extend more than half an inch on the left side, which had the corpus luteum. The coagulum was thickest at the orifice of the tube, and there adhered to the inner surface for the eighth part of an inch; beyond which it became smaller and terminated in a point. In the left tube the coagulum was in two places coiled or folded upon itself, as if thrown back by the action of the tube. The portions of the coagulum at the orifices of the tubes were hollow. When the inner surface of the cavity of the uterus was examined with a magnifying glass it was found extremely vascular, and dotted with innumerable whitish spots too small to be seen by the naked eye. In the examination of this uterus and Fallopian tubes, as Mr. Hunter's chief object was the detection of the embryo, no precaution was omitted which could be devised to prevent it being overlooked or destroyed. The uterus was opened in a bason of clear water, the incision was conducted with great circumspection, and very slowly continued, till the whole of the cavity was exposed. Every part of the internal surface was minutely examined with magnifying glasses; but in no situation was there anything resembling an embryo to be found. The presence of a corpus luteum, the enlargement of the uterus, the newly-formed vascular membrane, or decidua, lining the cavity, and ihe history of the case, sufficiently prove conception to have taken place; and the embryo being nowhere detected by an examination so accurate and conducted by an anatomist so skilful in minute investigation, would induce a belief that the foetus had not been sufficiently advanced to take on a regular form. The appearances in the uterus, here described, the late Dr. Hunter, in his lectures, mentioned to have seen at -a. very early period after impregnation : so far they are not entirely new. The accuracy of the examination renders this case valuable, as it seems to enable us to decide a point hitherto not at all understood—that certain changes in the uterus not only take place previous to the 92 HUNTER ON THE ANIMAL GECONOMY. reception of the foetus, but that the foetus does not acquire a visible form for some time after these changes have been made.*

* [The positive conclusions deduced from this case, viz., that certain changes take place in the uterus within one month after conception, have been confirmed by all those anatomists who have enjoyed similar opportunities of examining the uterine organs within the same period. These changes consist essentially in the effusion of fibrin or coagulable lymph from the villi of the lining membrane of the uterus, which villi also become much elongated and highly vascular; and minute vessels are continued from them into the effused lymph, forming loops or arches in that substance. This process is compared by Hunter, in the following paper, to the effusion of lymph consequent on the introduction of an extraneous living part into any of the cavities of the body; and Professor von Baer, in a recent elaborate description of the uterus of a female who drowned herself eight days after impregnation, makes the same comparison. Professor Weber, in an examination of the uterus seven days after conception, also speaks of the great vascularity of its inner surface, and describes the villi as consisting of small cylinders placed perpendicularly to the inner surface of the uterus, united by a slimy membrane, and forming together a layer of a pale soft substance, from half a line to a line in thickness; whilst in some places the cylinder presented the length of from two to three lines. With respect to the negative results of Mr. Hunter's examination relative to the reception of the foetus in the uterus, and " its acquisition of a visible form," I suppose that the word ' fetus' is here used to express the product of generation, or ovum, especially as it is stated, that " in the examination of the uterus and Fallopian tubes Mr. Hunter's chief object was the detection of the 'embryo.'" Now if the product of generation were really expected to have been seen in that state of development which we understand by the terms embryo and fetus, its presence was most likely overlooked; since, from the analogy of the dog and rabbit, it most probably would have existed merely as a small pellucid vesicle or ovum, supposing that it had escaped from the ovarium; and it is to be regretted that the expression " there was found in the left 'ovarium' a corpus luteum" is all the evidence on that point which the present case affords. In the bitch, Von Baer has shown that the ova pass into the Fallopian tubes on the eight day after impregnation, and that when they reach the uterus they lie quite free in its cavity, are perfectly transparent, of a somewhat elongated form, and extremely delicate texture, and are from half a line to a third of a line in diameter. In the rabbit, the observations of De Graaf, of Prevost and Dumas, and of Coste, prove that the ova pass into the tubes the third (or, according to Coste, the second) day after impregnation; they reach the horns of the uterus on the fourth day, and are then about a line in diameter, in the form of pellucid bubbles, free and moveable. According to Home, the human ovum has reached the uterus on the eighth day after impregnation, when it is described as presenting an elliptical form, rather more than a line (^ parts of an inch) in length, and ^U parts of an inch in breadth. It is composed of two membranes, of which the external is of considerable thickness and consistence, very little transparent, quite smooth, and milkwhite; the internal membrane or bag consist 'of a seemingly very thin, perfectly smooth, and glossy membrane, which seemed to have considerable strength.' This internal membrane contained a thick, slimy matter, like honey, and " two round corpuscles, apparently more opake, and of a yellowish tint," regarded as " the probable seat of the future heart and brain." On comparing the preceding account with the observations that have been made on the mammiferous ovum, it will be found that the nearest resemblance to the supposed human ovum obtains in that of the ornithorhynchus, at least in the texture of the two membranes described, of which the external must be regarded as the chorion, the internal as the membrana vitelli. In the ornithorhynchus, as in the ovo-viviparous reptiles, the chorion is dense and unyielding ; but in the specimens ON THE STRUCTURE OF THE PLACENTA. 93 7. ON THE STRUCTURE OF THE PLACENTA.

The connexion between the mother and foetus in the human subject, has in every age, in which science has been cultivated, called forth the attention of the anatomist, the physiologist, and even the philosopher; but both that connexion, and the structure of the parts which form the connexion, were unknown till about the year 1754. The subject is certainly most interesting, and the discovery important ; and it is my intention, in the following pages, to give such an account of it as 1 hope may be acceptable to the public;* while, at the same time, I establish my own claim to the discovery. But that I may not seem to arrogate to myself more merit than I am entitled to, let me in justice to another person relate what follows. The late indefatigable Dr. MacKenzie, about the month of May, 1754, when assistant to Dr. Smellie, having procured the body of a pregnant woman, who died undelivered at the full term, had injected both the veins and arteries with particular success, the veins being filled with yellow, the arteries with red.f Having opened the abdomen, and exposed the uterus, he made an incision into the fore part, quite through its substance, and came

which we examined, and which, as in SirEverard Home's case, had been subjected to the action of spirit, the chorion was semitransparent. In those mammalia, however, which approximate the human species in the placental development of the fetus, the ovum, when it has been detected unattached in the uterus, has invariably presented a translucency and delicacy of its membranes, with which the structure of the human ovum, as described by Home, is totally at variance; and, from the tenor of the whole account, we believe the object to have been what Mr. Bauer, to whom its description and delineation were confided,3- declared it to resemble, viz., the egg of an insect. Rejecting, then, the description we have just been considering,—and its apocryphal character is rightly admitted by all physiologists of the present day, who have investigated the nature of the mammiferous ovum,—the determination of the period of the passage of the human ovum into the uterus after impregnation, and its condition and structure when first received into that cavity, still remain open to the researches of the physiologist] * This paper was read at the Royal Society, but as the facts had before that time been given to the public, it was not published in the Philosophical Transactions. t Dr. MacKenzie being then an assistant to the late Dr. Smellie, the procuring and dissecting this woman without Dr. Smellie's knowledge was the cause of a separation between them, for the leading steps to such a discovery could not be kept a secret. The winter following Dr. MacKenzie began to teach midwifery in the Borough of Southwark. a " As the ovum was so extremely small as to admit of dispute whether it was one or not, I carried it immediately to Kew, to Mr. Bauer, who, after examining it, said it looked like the egg of an insect."—Phil. Trans., p. 255. Mr. Clift who laid open the uterus in question, and patiently scrutinized the whole of its cavity without perceiving any trace of an ovum, has always been of opinion that the one afterwards detected by Home was dropped from one of the numerous flesh-flies which were buzzing about at the time of the examination. 94 HUNTER ON THE ANIMAL CECONOMY. to what seemed to be an irregular mass of. injected matter. The appearance being new he proceeded no further, and greatly obliged me, by desiring my attendance to examine parts, in which the appearances were so uncommon. The examination was made in his presence, and in the presence of several, other gentlemen, whose names I have now forgotten ; but I have reason to believe that some are settled in this country, who I hope will have an opportunity of perusing this publication.* I first raised, with great care, a part of the uterus from the irregular mass, and in doing this observed regular pieces of wax passing obliquely between it and the uterus, which broke off, leaving part attached to that mass; and on attentively examining the portions towards the uterus, they plainly appeared to be a continuation of the veins passing from it to this substance, which proved to be placenta. I likewise observed other vessels, about the size of a crow-quill, passing in the same manner, although not so obliquely ; these also broke upon separating the placenta and uterus, leaving a small portion on the surface of the placenta ; and on examination they were discovered to be continuations of the arteries of the uterus. My next step was to trace these vessels into the substance of what appeared placenta, which was first attempted in a vein; but that soon lost the regularity of a vessel, by terminating at once upon the surface of the placenta in a very fine spongy substance, the interstices of Which were filled with the yellow injected matter. This termination being new, I repeated the same kind of examination on other veins, which always led me to the same terminations, never entering the substance of the placenta in the form of a vessel. I then examined the arteries, tracing them in the same manner towards the placenta, and found that, having made a twist, or close spiral turn upon themselves, they-were lost on its surface. On a more attentive view, I perceived that they terminated in the same way as the veins; for opposite to the mouth of the artery the spongy substance of the placenta was readily distinguished with the red injection intermixed. Upon cutting into the placenta I discovered, in many places of its

* If I should be so fortunate as to have this publication fall into any of those gentlemen's hands, I hope they will favour me with their opinion of my state of the facts, which led to the discovery. „ It may be suspected by some (but none I hope to whom I have the pleasure of being known,) that I am not doing Dr. MacKenzie justice, and am perhaps suppressing some part of that share of the discovery to which he is entitled. This idea (if ever it should arise), I may probably not be able to remove; but I hope it will also be seen that I myself have given rise to it; believing, if I had been so inclined, that I might have suppressed Dr. MacKenzie's name altogether without ever running the hazard of being detected. I was indeed so tenacious of my claim to the discovery, that I wrote this account in Dr. MacKenzie's lifetime, with a design to publish it; and often communicated my intentions to Dr. George Fordyce, who 1 knew was very intimate with the Doctor, in consequence of both teaching in the same place, and making many experiments together; therefore he is a kind of collateral witness, that what I now publish is the same account which I gave in Dr. MacKenzie's lifetime. ON THE STRUCTURE OF THE PLACENTA. 95 substance, yellow injection, in others red, and in many others these two colours mixed. The substance of the placenta, now filled with injection, had nothing of the vascular appearance, nor that of extravasation, but had a regularity in its form which showed it to be naturally of a cellular structure, fitted to be a reservoir for blood. I perceived, likewise, that the red injection of the arteries (which had been first injected), had passed out of the substance of the placenta into some of the veins leading from the placenta to the uterus, mixing itself with the yellow injection ; and that the spongy chorion, called the decidua by Dr. Hunter, was very vascular, its vessels going to and from the uterus, being filled with the different coloured injections. After having considered these appearances, it was not difficult for me to determine the real structure of the placenta and course of the blood in these parts: but the company, prejudiced in favour of former theories, combated my opinion ; and it was even disputed whether or not these curling arteries could carry red blood. After having dissected the uterus, with the placenta and membranes, and made the whole into preparations, tending to show the above facts, I returned home in the evening, and communicating what I had discovered to my brother, Dr. Hunter, who at first treated it and me with good-humoured raillery; but on going with me to Dr. Mac- Kenzie's he was soon convinced of the fact. Some of the parts were given to him, which he afterwards showed at his lectures, and probably they still remain in his collection. Soon after this time Dr. Hunter and I procured several placentae, to discover if after delivery, the termination of the veins and the curling arteries could be observed ; they were discernible almost in every one ; and by pushing a pipe into the placenta we could fill not only its whole substance, but also the vessels on that surface which was attached to the uterus, with injection. The facts being now ascertained and universally acknowledged, I consider myself as having a just claim to the discovery of the structure of the placenta, and its communication with the uterus, together with the use arising from such structure and communication, and of having first demonstrated the vascularity of the spongy chorion. It is not necessary at present to enter into the various opinions which have been formed on this subject; because, whatever they were, they could not be just, the structure of the parts not being known : neither shall I endeavour to give a complete description of all the parts immediately connected with uterine gestation, but content myself with describing the structure of the placenta, as far as it has any relation to the uterus and child; and with explaining the connexion between the two ; leaving the reader to examine what has been said upon this subject by others, especially by Dr. Hunter, in that very accurate and elaborate work which he has published on the Gravid Uterus, in which he has minutely described and accurately delineated the parts, without mentioning the mode of discovery. 96 HUNTER ON THE ANIMAL O3C0N0MY.

The necessary connexion, subsisting in all animals between the mother and foetus, for the nourishment of the latter, as far as I know, takes place in two ways. In some it is continued, and subsists through the whole term of gestation ; in others the union is soon dissolved ; but an apparatus is provided, which at once furnishes what is sufficient for the support of the animal till it comes forth. The first of these are the viviparous, the second the oviparous animals, both of which admit of great variety in the mode by which the same effect is produced.* In the first division is included the human species, which alone will engage our present attention. But before I describe this connexion, it may be necessary that the reader should understand my idea of generation: I shall therefore refer him to what I have said upon that subject in my account of the free-martin.f In the human species, the anatomical structure of the mother and embryo, relative to foetation, being well known, it will only be necessary fully to describe the nature of the connexion between them, which is formed by the intermediate substance called placenta. For this purpose we must first consider the placenta as a common part; next, the uterus as belonging to the mother, yet having an immediate connexion with the placenta, from which the nourishment of the foetus is to be derived, which will lead us lastly to a consideration of those peculiarities of structure by means of which the fcetus is to receive its nourishment, and which likewise constitutes its immediate communication with the placenta. It is the structure of this intermediate substance, and its connexion with the child and the uterus of the mother, which have hitherto been so little understood, and without any accurate knowledge of which it was impossible any just idea could be formed of its functions. The placenta is a mass lying nearly in contact with the uterus; indeed it may in some degree be said to be in continuity with a part of its internal surface. On the side applied to the uterus the placenta is lobulated, having deep irregular fissures. It is probably, from this structure of the placenta, that the uterus has an intestine motion while in the time of uterine gestation, not an expulsive one; which those lobes of the placenta allow of; but all these lobes are united into one uniform surface on that surface next to the child, where its umbilical vessels ramify. When we cut into the placenta its whole substance appears to be little else than a network, or spongy mass, through which the blood-vessels of the fcetus ramify, and indeed seems to be principally formed by the ramifications of those vessels; it exhibits hardly any appearance of connecting membrane; but we cannot readily suppose it to be without such a membrane, as there is so much

* It may be remarked here, that the oviparous admit of being distinguished into two classes, one where the egg is hatched in the belly, as in the viper, which has been commonly called viviparous; the others, where the eggs have been first laid and then hatched, which is the class commonly called oviparous, such as all the bird tribe: and many others, as snakes, lizards, &c. f See page 70. ON THE STRUCTURE OF THE PLACENTA. 97 regularity in its texture. The cells, or interstices of each lobe, communicate with one another, even much more freely than those of the cellular membrane in any other part of the body; so that whatever fluid will pass in at one part, readily diffuses itself through the whole mass of lobe; and all the cells of each lobe have a communication at the common base. This structure of the placenta, and its reciprocal communication with the two bodies with which it is immediately connected, form the union between the mother and fcetus for the support of the latter. Prior to the time I have mentioned above, anatomists seem to have been wholly unacquainted with the true structure of placenta. By notes taken from Dr. Hunter's lectures, in the winter 1755-6, it appears that he expressed himself in the following manner.* " The substance of the placenta is a fleshy mass, which seems to be formed entirely of the vessels of the umbilical rope." In another part, mentioning the appearances when injected, he says: " and upon a slight putrefaction coming on, you will find the whole appearing like a mass of vessels :" then says," there is always a white uninjected substance between the vessels; but whether lymphatics or what I cannot tell." This uninjected substance, mentioned by Dr. Hunter, is what forms the cellular structure. The placenta seems to be principally composed of the ramifications of the vessels of the embryo, and may have been originally formed in consequence of those next to the uterus laying hold by a species of animal attraction of the coagulable lymph which lines the uterus. It might take place in a manner resembling what happens when the root of a plant spreads on the surface of moist bodies, with this difference, that in the present instance the vessels form the substance through which they ramify, as in the case of granulations. At the time, or perhaps before, the female seed enters the uterus, coagulable lymph, from the blood of the mother, is thrown out everywhere on its inner surface, either from the stimulus of impregnation taking place in the ovarium, or in consequence of the seed being expelled from it. But I think the first the most probable supposition; for we find in extra-uterine cases that the decidua is formed in the uterus, although the ovum never enters it, which is a proof that it is produced by the stimulus of impregnation in the ovarium, and that it is prior to the entrance of the ovum into the uterus. When it has entered the uterus it attaches itself to that coagulable lymph, by which, being covered and immediately surrounded,f there is formed a soft pulpy membrane, the decidua, which I believe is peculiar to

* These quotations were taken from Mr. Galhie's MS. of Dr. Hunter's lectures, who is one of the gentlemen that favoured Dr. Hunter, upon a former occasion, with the use of his notes. See Dr. Hunter's Commentaries. t This is somewhat similar to another operation in the animal ceconomy. If an extraneous living part is introduced into any cavity it will be immediately inclosed with coagulable lymph. Thus we find worms inclosed, and hydatids that have been detached, afterwards inclosed ; but in those cases this is a consequence of the pressure of the extraneous body, whereas in the uterus it is nreparatory. r in 98 HUNTER ON THE ANIMAL O3C0N0MY. the human species and to monkeys, I never having found it in any other animal. That part which covers the seed or foetus, where it is not immediately attached to the uterus, and likewise forms a membrane, was discovered by Dr. Hunter, and is by him called decidua reflexa.* The whole of this coagulable lymph continues to be a living part for the time; the vessels of the uterus ramify upon it; and where the vessels of the foetus form the placenta there the vessels of the uterus, after passing through the decidua, open into the cellular substance of the placenta, as before described. As this membrane lines the uterus and covers the seed, it is stretched out, and becomes thinner and thinner, as the uterus is distended by the foetus growing larger, especially that part of it, called decidua reflexa, which covers the foetus; as there it cannot possibly acquire any new matter, except we could suppose that the foetus assisted in the formation of it. This membrane is most distinct where it covers the chorion; for where it covers the placenta it is blended with coagula in the great veins that pass obliquely through it, more especially all round the edge, where innumerable large veins come out; but the chorion and decidua can be easily distinguished from one another, the decidua being less elastic. From the description now given, I think we are justified in supposing the placenta to be formed entirely by the foetus, which is further confirmed by extra-uterine cases, and by the formation of the membrane in the egg, there being no living organic part to furnish them; and the decidua we must suppose to be a production of the mother : of both which the circumstance of the decidua passing between the placenta and uterus may be considered as an additional proof. For if the vessels of the foetus branched into a part of the decidua, we might conceive the whole placenta to be formed from that exudation; the portion of it, where the vessels had ramified like the roots of a plant, becoming thicker than the rest, and forming the placenta. If that were the case, this membrana decidua, when traced from the parts distinct, and at a distance from the placenta, should be plainly seen passing into its substance all round at the edges, as a continuation of it. But the fact is quite otherwise; for the decidua can be distinctly traced between the placenta and uterus, hardly ever passing between the lobuli, the vessels of the fcetus never entering into it, and of course none of them ever coming in absolute contact with the uterus. But what may be considered as still a stronger proof that the decidua is furnished by the uterus is, that in cases of extra-uterine conception, where the foetus is wholly in the ovarium or Fallopian tube, we find the uterus lined with the decidua, having taken on the uterine *The. spongy ch placenta is certainly a foetal part, and is formed on the inside of the ™w 1 £horion'°F decidua. How far the decidua reflexa is a uterine part I do 1, y" • °w 5 if it is, then the ovum must be placed in a doubling of the coagu- 1p2h™ 5, TSihe-decidua; but if the ovum is attached to the inside of the decidua, then the decidua reflexa is belonging to the fcetus. ON THE STRUCTURE OF THE PLACENTA. 99

action; but no placenta, that being formed by the fcetus, and therefore in the part which contained it. The vessels of the foetus adhering, by the intervention of the decidua, to a certain portion of the uterus when both are yet small, as the uterus increases in every part of its surface during the time of uterine gestation, we must suppose that this surface of adhesion increases also; and that by the elongation of those vessels of the fcetus in every direction this substance should likewise be increased in every direction. This is in some degree the case, yet the placenta does not occupy so much of the enlarged surface of the uterus as one at first would expect. The vessels of the uterus in the time of the gestation are increased in size nearly in a proportion equal to the increased circumference of the uterus, and consequently in a proportion much greater than the real increase of its substance. But when we reflect that the uterus ought not to be considered as hollow, but as a body nearly solid, on account of its contents, which derive support from this source, and that a much greater quantity of blood must necessarily pass than what is required for the support of the viscus itself, we cannot be at a loss to account for the greatly increased size of its vessels. The arteries which are not immediately employed in conveying nourishment to the uterus go on towards the placenta, and, proceeding obliquely between it and the uterus, pass through the decidua without ramifying; just before they enter the placenta, after making two or three close spiral turns upon themselves, they open at once into its spongy substance without any diminution of size, and without passing beyond the surface, as above described. The intention of these spiral turns would appear to be that of diminishing the force of the circulation in the vessels as they approach the spongy substance of the placenta, and is a mechanism calculated to lessen the quick motion of the blood in a part where a quick motion was not required. These curling arteries at this temination are in general about half the size of a crow's quill, and sometimes larger. The veins of the uterus appropriated to bring back the blood from the placenta commence from this spongy substance by such wide beginnings as are more than equal to the size of the veins themselves. These veins pass obliquely through the decidua to the uterus, enters its substance obliquely, and immediately communicate with the proper veins of the uterus. The area of these veins bears no proportion to their circumference, the veins being very much flattened. This structure of parts points out at once the nature of the blood's motion in the placenta; but as this is a fact but lately ascertained, a just idea may perhaps be conveyed by saying that it is similar, as far as we yet know, to the blood's motion through the cavernous substance of the penis. The blood, detached from the common circulation of the mother, 100 HUNTER ON THE ANIMAL O2C0N0MY. moves through the placenta of the fcetus; and is then returned back into the course of the circulation of the mother, to pass on to the heart. This structure of the placenta, and its communication with the uterus, leads us a step further in our knowledge of the connexion between the mother and the fcetus. The blood of the mother must pass freely into the substance of the placenta, and the placenta most probably will be constantly filled ; the turgidity of which will assist to squeeze the blood into the mouths of the veins of the uterus, that it may again pass into the common circulation of the mother; and as the interstices of the placenta are of much greater extent than the arteries which convey the blood, the motion of the blood in that part must be so much diminished as almost to approach to stagnation. So far and no further does the mother appear to be concerned in this connexion. The fcetus has a communication with the placenta of another kind. The arteries from the fcetus pass out to a considerable length, under the name of the umbilical arteries, and when they arrive at the placenta ramify upon its surface, sending into its substance branches which pass through it, and divide into smaller and smaller, till at last they terminate in veins; these, uniting, become larger and larger, and end in one, which at last communicates with the proper circulation of the fcetus. This course of vessels, and the blood's motion in them, is similar to the course of the vessels and the motioV of'the blood in other parts of the body.*

* [It is well known that the accuracy of this description has been disputed by several continental anatomists, and has especially been called in question in this country by Dr. Robert Lee, F.R.S., who, with a zeal becoming a sincere lover of truth, deemed it his duty to submit to the scientific world the results of a series of investigations, which he considered to beirreconcileablein some respects with the Hunterian descriptions. During the period in which Dr. Lee was examining, at the College of Surgeons, the Hunterian Preparations, illustrative of the structure and connexions of the placenta, his observations on the obscurity produced by apparently extravasated injection, led me to think of some less objectionable mode of demonstrating the vascular communication between the uterus and placenta, if it existed ; or of proving, more satisfactorily than the appearance pointed out by him in the Hunterian preparations seemed to do, that there was no such communication. This I proposed to do by dissecting the parts under water before disturbing them, either by throwing forcibly foreign matter into the vessels, or by separating the placenta from the uterus, to observe the appearances presented by the opposed surfaces; a proceeding which, if done in the air, is liable to the objection of the possibility of having torn the vessels which were passing across, and the coats of which are acknowledged to be extremely delicate. For this purpose I was furnished by Dr. Lee with sections of an uninjected and naturally connected uterus and placenta, at the sixth month of uterine gestation, which I fixed under water in an apparatus used for dissecting mollusca, and commenced the dissection from the outside, removing successively, and with great care, the layers of fibres, and tracing the veins as they passed deeper and deeper in the substance of the uterus in their course to the deciduous membrane; in which situation, as the thinnest pellicle of membrane is rendered distinct by being supported in the ambient fluid, I naturally expected to see the coats of the veins ON THE STRUCTURE OF THE PLACENTA. 101 In addition to what I have said about the connexion between the mother and child in natural cases, it is necessary to observe, that

continued into the deciduous membrane and placenta, and to be able to preserve the appearance in a preparation, if it actually existed in nature. Every vein, however, wheo traced to the inner surface of the uterus, appeared to terminate in an open mouth on that aspect; the peripheral portion of the coat of the vein, or that next the uterus, ending in a well-defined and smooth semicircular margin, the central part adhering to, and being continuous with, the decidua. In the course of this dissection I observed that where the veins of different planes communicated with each other, in the substance of the walls of the uterus, the central portion of the parietes of the superficial vein invariably projected in a semilunar form into the deeper-seated one ; and where (as was frequently the case, and especially at the point of termination on the inner surface), two, or even three, of these wide venous channels communicated with a deeper sinus at the same point, the semilunar edges decussated each other so as to allow only a very small part of the deep-seated vein to be seen. It need scarcely be observed how admirably this structure is adapted to insure the arrest of the current of blood through these passages, upon the contraction of the muscular fibres with which they are everywhere immediately surrounded. On another portion of the same uterus and placenta, I commenced the examination under water by turning off the placenta and deciduous membrane from the inner surface of the uterus. In this way the small tortuous uterine arteries which enter the deciduous membrane were readily distinguishable, though not filled with injected matter; and, as it was an object to avoid unnecessary force in the process of separation, they were cut through, though they are easily torn from the decidua. But with respect to the veins, they invariably presented the same appearances as were noticed in the first dissection, ternajnating in open semicircular orifices, which a/e cloSjetH^Jl&fit apposition of the deciduous membrane and placenta. Th^fcilNibrWre^is, however, thinner opposite these orifices than elsewhere, and in some places appeared to be wanting, or, adhering to the vein, was torn up with it; but in these cases the minute vessels of the placenta only appeared, and never any indication of a vascular trunk or cell commensurate with the size of the vein whose terminal aperture had been lifted up from the part. The above results of my examination of the impregnated uterus, which had been furnished to me by Dr. Lee, I communicated, as I had promised to do, to that gentleman. They appeared decisive of the fact that the veins of the uterus were not continued as such across the decidua, to terminate in visible cells in the substance of the placenta; but whether the terminal orfices of the veins derived no returning blood from the interstices of the decidual lamina;, was by no means certain. For my own part, having satisfied myself of the passage of the tortuous uterine arteries into the decidua, I undoubtedly considered the uterine venous sinuses as the most probable and natural channels by which the blood conveyed from the uterus by the tortuous arteries would return again to that body ; although I was unable to determine from this dissection how the blood was returned into the open mouths of the veins. It must be admitted, that an impregnated uterus at the fifth month, where the vessels, which are very small, had been contracted by the spirit in which the parts had been preserved, was not a very favourable subject for so delicate an investigation ; and I accordingly felt extremely desirous of repeating the dissections on gravid uteri at a more advanced period. These opportunities do not, as is well known, frequently occur: about a year after I was, however, favoured by Dr. Lee with a large portion of a gravid uterus of a woman who died about the ninth month of gestation, in which the uterine veins had been gently filled with red size injection. This preparation was submitted tothe same mode of dissection. In tracing those veins which passed to the inner surface of the uterus, near the middle of the placenta, the injection was seen to be continued from them into oblique, wide/but shallow channels, leading through the> externa I ecid«i into the placental'decidua, and had thence been diffused through the fine spongy 10* 102 HUNTER ON THE ANIMAL CECONOMY. though the uterus is appropriated for the support of the fcetus, as best fitted for that purpose, yet it is not essential to its growth; as any other part in which the child may be situated, is capable of receiving the same provisionary stimulus for supplying it with nourishment as the nterus ; and this, I believe, is peculiar to generation. This prompts me to make the following observations upon the different situations of the fcetus in extra-uterine cases, which are extraordinary, happen seldom, and when they do occur are often attended with so many hindrances to critical investigation, as hardly to allow of thorough or satisfactory information. Such cases are readily distinguished from natural ones by the uterus being found entire and empty ; and they may be divided into three different kinds, according to the situation of the fcetus in the ovarium, Fallopian tube, or in the cavity of the abdomen. From a want of the appearances which usually attend the natural process, the investigation of extra-uterine cases is attended with considerable difficulty. For where uncommon actions have taken place, as well as in cases of disease, the natural texture of the parts

cellular tissue which everywhere surrounds and supports the foetal capillaries. On comparing these appearances with my first dissection, I perceived that the uterine vein, opposite the mouth of which I had supposed the decidua to be wanting, and whose orifice was in contact with the capillaries of the placenta, was in reality one of the oblique decidual canals, returning the blood from the cellular substance of the placenta into the uterine vein, its continuity with which had been preserved. The continuation of the uterine veins into decidual canals was much more distinct in those which terminated near the circumference of the placenta ; and here the irregular portions of injection, which filled the canals as far as the surface of the placenta, were evidently circumscribed, by distinct parietes, and not the result of confused extravasation: the injection from the decidual canals had passed into the large interlobular spaces, or maternal sinuses of the placenta, and thence had become diffused, generally for the extent of an inch, into the spongy or cellular texture of the placenta. The uterine arteries in this case had not been injected, but were easily traceable passing through the external and placental decidua, as for as the internal surface of the latter, and apparently opening or being lost on the spongy surface of the placenta. With reference to preparations of vascular and cellular structures like the placenta, it is not easy to enforce conviction from the appearances they present, in consequence of the difficulty of distinguishing between natural and accidental extravasation. Having, however, carefully compared the Hunterian preparations with the results of my own examinations of the gravid uterus at the full period, I now believe they all fully bear out Mr. Hunter's general view, viz., that the maternal blood is diffused, by means of the tortuous arteries, into the spongy cellular substance of the placenta, where it bathes the capillaries of the foetal circulation, and is returned by the oblique decidual adventitious sinuses and channels into the orifices of the uterine veins. Thus the placental intercommunication between the fcetus and mother, in the human subject and Quadrumana, is carried on by the contact of the foetal capillaries with maternal extravasated blood ; while in the Ruminants, the mare, and the sow,* it takes place by the apposition of capillaries to capillaries, and the two parts of the placenta, viz., foetal and maternal, can be separated. In the Ferae and Rodentia there appears to be an intermediate structure.] a [In the last two examples the placenta may be 6aid to be diffused oyer nearly the whole surface of the chorion.] ON THE PLACENTA OF THE MONKEY. 103 is very much altered, and appears to be lost, not only by the parts themselves being enlarged, but from having a great deal of new matter superadded to them, by which they lose their natural distinctness, and become less fitted for examination than those which only have a relation to them, and which preserve their natural actions peculiar to that state. From these difficulties, and a want of accuracy in those who made the examination, it is not at present clear, with respect to many of the extra-uterine cases upon record, whether they were ovarian cases, Fallopian tube cases, or abdominal cases; when, if they had been acquainted with the principle in which they differ, nothing could have been more easy than to distinguish them. It is not difficult, perhaps, at the very first view, to distinguish an abdominal case from either of the two first: for if the ovaria and Fallopian tube are entire, natural, and can be well distinguished to be as those parts are when the circumstances are natural, then we may be sure it is an abdominal case. Appearances, however, may not in all cases be distinct; but the parts may adhere, or be otherwise rendered so obscure, that an abdominal case might be confounded with either of the two first; therefore it is essential to have a characteristic difference established between the two first, and the third. The invariable difference between the two first, and the abdominal cases, will be in the vessels by which the child is nourished: for the arteries and veins belonging to the part in which the child is contained must be enlarged; which, being the increase of a natural part, will be readily ascertained, and the nature of the case as readily determined. We may lay it down as a principle, that when the spermatic artery and veins of either side are enlarged in an extra-uterine case, that the fcetus is in the ovarium or Fallopian tube; since there are no other blood-vessels which supply these parts; and if any other system of vessels, as the mesenteric, are increased in size, while the spermatic are in a natural state, we may with equal certainty conclude the fcetus to be contained in the general cavity of the belly. As this becomes the great criterion, and as the situation and time will not always allow very nice investigation on the spot, where the person employed has an opportunity of taking away the parts concerned, I would advise his taking along with them the aorta and vena cava, cut through above the origins of the spermatic vessels. 8. OBSERVATIONS ON THE PLACENTA OF THE MONKEY.

Monkeys always copulate backwards: this is performed sometimes when the female is standing on all-fours; and at other times the male brings her between his thighs when he is sitting, holding her with his fore paws. 104 HUNTER ON THE ANIMAL OJCONOMY. The female has her regular periods for the male, but she has commonly too much complaisance ever to refuse him. They carry this still further, for they receive the male when with young, even when pretty far gone : at least this was the case with one of which I am going to give an account. A female monkey, belonging to Mr. Endersbay, in the summer 1782, had frequently taken the male. The keeper observed that after the 21st of June she became less lively than usual, although it was not suspected that she had conceived ; but some time after appearing to be bigger in the belly, it created a suspicion of her being with young. Great attention was paid to her, and great care was taken of her. She went on gradually increasing in size ; and at last something was observed to mf)ve in her belly at particular times, and the motion could even be felt through the abdominal muscles. She became indolent, and did not like to leap or perform her usual feats of activity. Towards the latter part of the time they perceived the breast and nipple to have become rather fuller, and that a kfnd of water could be squeezed out at the nipple. Some time before she brought forth, she became red about the hips and posteriors, which redness extended to the inside of the thighs. It being now certain that she was with young, I desired that she might be particularly attended to when there were signs of approaching delivery, both on her own account and that of the young one, and requested the afterbirth might be carefully preserved, as that part would assist to ascertain the mode of uterine gestation. These directions were attentively followed; and when in labour it was observed that she had regular pains, that when the young one was in part come into the world, she assisted herself with her fore paws, and that it came with the hind parts first. This happened on the 15th of December 1782, in all about six months after conception ; and when she brought forth her young one it showed signs of life, but died immediately, owing probably to the unfavourable mode of its being brought into the world. When delivered she took the young one up, and although it was dead clasped it to her breast. The afterbirth was preserved entire, and was perfectly fit for examination. It consisted of placenta, with the membranes and navel-string, which all very much resembled the corresponding parts in the human subject, as will now be described. The placenta had the appearance of being divided into two oblong bodies, united by their edges, each terminating in an obtuse point at the other end, which were of course at some little distance from one another. It is probable that these two points were placed towards the openings of the Fallopian tubes, where the uterus assumes a form resembling two obtuse horns. The two lobes above-mentioned were made up of smaller ones, united closely at their edges, which were more apparent and distinct at some parts than at others. Some of these lobes were divided by fissures which seem to be derived from one centre, while OF A WOMAN WHO HAD THE SMALL-POX, ETC. 105

there were others near the edges passing in a different direction, in which fissures are placed veins or sinuses that receive the blood laterally from the lobes. The substance of the placenta seems to be cellular, as in the human subject: this structure allows a communication to be kept up between different parts of each lobe, and the sinuses allowing of a communication between the different lobes of which the placenta is composed, the blood passes into the fissures before it enters the veins; in which respect it differs from the human placenta. The arteries from the uterus, on the surface of the placenta, were visible, but too small to be injected: I cannot therefore say how they terminated in the placenta. The principal veins arose in general from the fissures beginning from the surface, as in the human placenta ; but besides these, there were other small ones; all which, we may suppose, pass through the decidua and enter the substance of the uterus, most probably in the same way as in the human subject. The membranes are the amnios, the chorion, and the membrana decidua. These appear to be much the same as in the human, except that the decidua is considerably thicker, especially where it passes between the uterus and the placenta. The navel-string in the monkey is not proportionally so long as in the human, and is very much and very regularly twisted. There is no urachus, and of course no allantois; not even the small ligament that appears to be a drawing-in of the bladder at its attachment to the navel, the bladder here being rounded. 9. ACCOUNT OF A WOMAN WHO HAD THE SMALL- POX DURING PREGNANCY, AND WHO SEEMED TO HAVE COMMUNICATED THE SAME DISEASE TO THE FCETUS. BY JOHN HUNTER, ESQ., F.R.S.* Read January 17, 1780.

Mr. Grant's Account. On the 5th of December, 1776, Mrs. Ford had been seized with shivering and the other common symptoms of fever, to which were added great difficulty of breathing and a very hard cough. Mr. Grant saw her on the 7th, and he took from her eight ounces of blood, and gave her a composition of the saline mixture with spermaceti and magnesia every six hours. This had operated by the 8th two or three times very gently, when most of the complaints were relieved ; but the cough still shaking her violently, bleeding seemed necessary to be repeated, more particularly as she looked upon herself to be in the sixth

* [Originally published in the Philosophical Transactions, vol. lxx., 1780.] 106 HUNTER ON THE ANIMAL O3C0N0MY.

month of her pregnancy. The medicine was continued without the magnesia. In the evening (viz.. the 8th) the small-pox appeared, which proved of a mild kind, and moderate in quantity. Its progress was rather slower than might have been expected; but the woman passed through the disease in great spirits, sitting up the greatest part of the day during the whole time, and taking only a paregoric at night, and, as occasion required, a little magnesia; thus the symptoms were mitigated, and the cough at last became very little troublesome. On the 25th she complained of a pain in her side. Eight ounces of blood were taken away. The next day she was quite free from pain, and thought herself as well on the 27th as her particular situation would admit of; after which she was not visited by Mr. Grant till the 31st, when she was in labour.

Mr. WastalFs Letter on the same subject.

December 30, 1776, I was sent for to Mrs. Ford, a healthy woman, about twenty-two years of age, who was pregnant with her first child. She had come out of the country about three months before. Soon after her arrival in town she was seized with the small-pox, and had been under the care of Messrs. Hawkins and Grant, who have favoured me with the particulars here annexed. I called upon her in the afternoon, she complained of violent griping pains in her bowels, darting down to the pubes. On examining, I found the os tincae a little dilated, with other symptoms of approaching labour. I sent her an anodyne spermaceti emulsion, and desired to be called if her pains increased. I was sent for. The labour advanced very slowly ; her pains were long and severe: she was delivered of a dead child with some difficulty. Observing an eruption all over the body of the child, and several of the pustules filled with matter, I examined them more particularly; and recollecting that Dr. Leake, in his Introductory Lecture to the Practice of Midwifery, had observed, that it might be necessary to inquire whether those adults who are said totally to escape the small-pox have not been previously affected with it in the womb, I sent a note to Dr. Leake, and likewise to Dr. Hunter, in hopes of ascertaining a fact hitherto much doubted. Dr. Leake came the same evening, and saw the child. Dr. Hunter came afterwards, with Mr. Cruickshank, and examined it; also Mr. John Hunter and Mr. Falconer; who all concurred with me, that the eruption on the child was the small pox. Dr. Hunter thought the eruption so like the small-pox that he could hardly doubt; but said, that in all other cases of the same kind that he had met with, the child in utero had escaped the contagion. OF A WOMAN WHO HAD THE SMALL-POX, ETC. 107 From Mr. Grant's Notes.

The eruption appeared on Mrs. Ford in the evening of the 8th of December, and she was delivered the 31st, that is, twenty-three days after the appearance of the eruptions.

Reflections by Mr. John Hunter.

The singularity of the above case, with all its circumstances, has inclined me to consider it with some attention. There can be no doubt that the mother had the small-pox, and that the eruption began to appear on the 8th of December; also, that it went through its regular stages, and that on the 31st, viz. twenty-three days after the first appearance of the eruption the 'woman was delivered of the child, who is the subject of this paper. Secondly, The distance of time when she had the small-pox before delivery, joined with the stage of the disease in the child when born, which probably was about the sixth or seventh day of the eruption, viz., about fifteen or sixteen days after the beginning of the eruption on the mother, perfectly agrees with the possibility of the infection's being caught from the mother. Thirdly, The external appearance of the pustules in the child was perfectly that of the srriall-pox, as must have appeared from the relation given in Mr. Wastall's letter. Most of the pustules were distinct, but some were blended or united at their base. The face had the greatest number, and these were in general the most indistinct. They were somewhat flattened, with a dent in the middle.* So far were the leading circumstances and external appearances in favour of their being the variolous eruption ; but although these leading circumstances and external appearances were incontrovertible, yet they were not an absolute proof of this being the genuine small-pox; therefore I must be allowed to consider this subject a little further, and see how far all the circumstances correspond or are similar to the true small-pox. In the small-pox we have a previous fever, in place of which, in the present case, we have no information but that of the mother's having had the smallpox within such a limited time as may favour the possibility of infection in the womb ; yet we may presume that the child must have had considerable fever preceding such an eruption, of whatsoever kind it was. In the small-pox the eruption goes through pretty regular stages in its progress and declension, which circumstances we know nothing of in the present case; but even this fever, the eruptions, and their

* I endeavoured to take some matter upon the point of two lancets; but not having an opportunity of making an experiment myself, I gave them to two gentlemen, who, I imagine, were afraid of inoculating with them. 108 HUNTER ON THE ANIMAL CECONOMY. progress, are not absolutely proofs that the disorder is the small-pox when it is caught in the common and natural way; and in proof of this assertion, it may be observed, that practitioners every now and then are mistaken. It maybe asked, What is the true characteristic of the small-pox 1 That by which it differs from all other eruptions that we are acquainted with 1 The most certain character of the small-pox that I know is, the formation of a slough, or a part becoming dead by the variolous inflammation; a circumstance which hitherto, I believe, has not been taken notice of. This was very evident in the arms of those who were inoculated in the old way, where the wounds were considerable, and were dressed every day; which mode of treatment kept them from scabbing, by which means this process was easily observed ; but in the present method of inoculation it is hardly observable; the sore being allowed to scab, the slough and scab unite and drop off together. The same indistinctness attends the eruptions on the skin; and in those patients who die of, or die while in, the disease, where we have an opportunity of examining them while the partis distinct, this slough is very evident. This slough is the cause of the pit after all is cicatrized ; for it is a real loss of substance of the surface of the cutis; and in proportion to this slough is the remaining depression. The chicken-pox comes the nearest in external appearance to the small-pox ; but it does not commonly produce a slough. As there is generally no loss of substance in this case, there can be no pit. But it sometimes happens, although but rarely, that there is a pit in consequence of chicken-pox; then ulceration has taken place on the surface of the cutis, a common thing in sores. In the present case, besides the leading circumstances mentioned in the case of the mother, corresponding with the appearances on the child, and the external appearances themselves, we have in the fullest sense the third and real or principal character of the small-pox, viz., the slough in every pustule ; from all which, I think, we may conclude, that the child had caught the small-pox in the womb; or at least a disease, the effects of which were similar to no other known disease. In opening the bodies of those who had either died of, or died while under, the small-pox, I always examined carefully to see whether any internal cavity, such as the oesophagus, trachea, stomach, intestines, pleura, peritoneum, &c, had eruptions upon them or not; and never finding any in any of those cavities, I began to suspect that either the skin itself was the only part of the body susceptible of such a stimulus, or that the skin was subject to some influence to which the other parts of the body were not subject, and which made it alone susceptible of the variolous stimulus. If from the first cause, I then concluded it must be an original principle in the animal ceconomy. If from the second, I then suspected that external exposure was the cause; and I was the more OF A WOMAN WHO HAD THE SMALL-POX, ETC. 109

led into this idea, from finding that these eruptions often attack the mouth and throat, two exposed parts; add to which, that we generally find the eruptions most on the exposed parts of the body, as the face, &c. With these ideas in my mind, I thought I saw the most favourable opportunity of clearing up this point. I therefore very attentively examined most of the internal cavities of this child; such as the peritoneum, pleura, trachea, inside of the oesophagus, stomach, intestines, &c, but observed nothing uncommon. I have already observed, that in this child the face and extremities were the fullest similar to what happens in common ; from all which I may be allowed to draw this conclusion, that the skin is the principal part which is susceptible of the variolous stimulus, and is not affected by any external influence whatever. The communication of the small-pox to the child in the womb may be supposed to happen in two ways; one by infection from the mother, as is supposed in the above case ; the other, by the mother's having absorbed the small-pox matter from some other person, and the matter being carried to the child from the connexion between the two, which we may suppose done with or without first affecting the mother. Testimonies and opinions are various with respect to these two facts. Boerhaave seems to have been led by his experience to think that such infection was not communicable; for we find that he attended a lady, who having, in the sixth month of her pregnancy, had the confluent small-pox, brought forth at the regular period a child, who showed not the least vestige of his mother's disease. His commentator, however, Van Swieten, supports a different opinion (see his Comment., vol. v.). He quotes a case from the Philosophical Transactions, vol. xxviii., No 337, p. 165, of a woman who, having just gone through a mild sort of small-pox, was, by means of a strong dose of purging physic, thrown into a miscarriage, and brought forth a dead female child, whose whole body was covered with variolous pustules full of ripe matter: but this history is founded only on the relation of a midwife to a clergyman, and therefore not absolutely to be depended upon as accurately stated; however, it is more than probable that there was a case as described, and that there were really eruptions on the skin of the child similar to the small-pox. Van Swieten likewise mentions what Mauriceau relates of himself. This author testifies that he had often heard his father and mother say that the latter, when big with him, and very near her time of delivery, had a painful attendance on one of her children, who died of the small-pox on the seventh day of the eruption; and that on the day following the death of this child Mariceau came into the world, bringing with him five or six true pustules of the small-pox. It does not appear, however, from this recital whether or not Mauriceau passed through life free from any posterior infection ; 110 HUNTER ON THE ANIMAL CECONOMY. but admitting that this eruption of Mauriceau's was truly the smallpox, yet I should very much doubt his having caught it from the child who died of it : as it should seem that the pustules of Mauriceau were of the same date with those of the child who died. Van Swieten appeals to a more recent case, which had been reported to him by persons of great credit, and is recorded in the Philos. Trans, vol. xlvi., p. 235. " A woman big with child, having herself long ago had the smallpox, very assiduously nursed a maidservant during the whole process of this disease. At the proper time she brought a healthy female child, in whose skin Dr. Watson asserted that he discovered evident marks of the small-pox, which she must have gone through in the womb; and the sa'me physician pronounced that this child would be free from future infection. After four years her brother was inoculated ; and Watson obtained permission of the parents to try the same experiment on the girl. The operation was performed on both children in the same manner, and the pus used in both cases was taken from the same patient. The event, however, was different: for the boy had the regular eruption, and got well; but the girl's arm did not inflame nor suppurate. On the tenth day from* the insertion of the matter she turned pale suddenly, was languid for two days, and afterwards was very well. In the neighbourhood of the incision there appeared a pustule, like those pustules that we sometimes observe in persons who, having had the disease, attend patients ill of the small-pox." In the Epistles of T. Bartholinus, Cent. II., p. 682, there is the following history: " A poor woman, aged thirty-eight years, pregnant, and now near the time of delivery, was seized with the symptoms of the small-pox, and had a very numerous eruption. In this state she was delivered of a child, as full of variolous pustules as herself. The child died soon after birth ; the mother three days afterwards." Van Swieten infers that the mother and the child were in this case infected at the same time; therefore, the child not infected by the mother. Dr. Mead asserts that when a woman in the small-pox suffers an abortion the fcetus is generally full of the contagion ; but that this does not happen always. This variety, he says, depends on the state of the mother's pustules when the child is born; that is, whether they are or are not in a state of purulence. Whence he has observed it sometimes to happen that on the second dav from the birth, or the third, or any day before the eighth, the disease caught from the mother shows'itself in eruptions on the child. Dr. Mead here relates the history of a ladv of quality, of which this is the substance. A lady, in the seventh month of her pregnancy, had the confluent small-pox, and on the eleventh day of the disease brought forth a son, having no signs of the disease on his body ; and she died on the fourteenth day. The infant having lived four days, was seized with convulsions, and, the small-pox appearing, died. The doctor infers from hence that, the suppuration being in OF A WOMAN WHO HAD THE SMALL-POX, ETC. U\

some measure completed on the eleventh day, the mother's disease was communicated then to the foetus, and made its appearance on the child after eight days. If there be no abortion, Dr. Mead pronounces that the child will ever be free from the disease, unless the birth should happen before the maturation of the pustules. He brings a case to prove that the fcetus in the womb may be infected by the contagion of which the mother does not partake. " A woman, who had long before suffered the small-pox, nursed her husband, under that disease, towards the end of her pregnancy; and was brought to bed at the due time. The child was dead, and covered all over with variolous pustules." With respect to the case quoted from Mauriceau, it has been proved by Sir George Baker (Med. Transact., vol. ii., p. 275), that Dr. Mead drew a conclusion from it directly contrary to the author's meaning. The negative opinion appears evidently to be supported by that history. Sir George Baker mentions in the same paper the case of two pregnant women who were inoculated at Hertford. They both had the small-pox favourably, and afterwards brought forth their children perfectly healthy at the usual time. Both these children, at the age of three years, were inoculated with effect. Sir George Baker likewise mentions a case which fell under the observation of Dr. Clarke of Epsom. " A woman towards the end of her pregnancy had the small-pox, from which she narrowly escaped. Five weeks after the crisis she was delivered of a healthy female child, who having numerous marks on her skin was judged by all who saw her to have undergone the same distemper before her birth. However, at the end of twelve months she had the small-pox in a very severe manner. Both the mother and child were lately living at Epsom." Since, then, we see that it is very probable that the small-pox may be caught from the mother when she is infected, it may be asked why does not this happen oftener 1 In answer to this we may suppose that this is not so ready a way as when the child is exposed to catch it after the birth, as we find too that a difference can be produced after birth; viz., inoculation is a much readier way of catching it than what is called the natural way. It may likewise be said that many women who are with child, and have the smallpox during pregnancy, do not recover; therefore both mother and child die before the' disease can have time to produce eruptions upon the child. Finally, in many of those cases where the mother recovers, there is sometimes produced a miscarriage, which also hinders the infection from taking place in the child. However, many women go through the whole disease, and the child shows no marks of the small-pox. Thus have I stated facts relative to^he present subject, with some of the best authorities on both sides of the question; and shall now leave the reader to form his own judgment. 112 HUNTER ON THE ANIMAL CECONOMY. 10. SOME OBSERVATIONS ON DIGESTION.

The paper which I formerly presented to the Royal Society, " On the Stomach itself being digested after Death," was published in 1772, in the 62d volume of the Philosophical Transactions, and has attracted the attention of Spallanzani* and others. In the course of these my observations I shall make some remarks upon the experiments and opinions of these gentlemen, compare them with those of Reaumur,-}- and, having given some general facts of my own upon digestion, shall conclude by adding a copy of the above-mentioned paper, with the hope that others will take up the subject in a more enlarged point of view, and prosecute an inquiry which is of so much consequence in the investigation of the operations of the animal ceconomy. I cannot at present spare sufficient time to give my opinions at large on this subject, with all the experiments and observations I have made upon it; but as soon as I have leisure I shall lay them before the public. To discover new parts has been a principal object in the researches of the young or practical anatomist; but the connexion, arrangement, mode of action, and uses of the whole, or of particular organs, have more commonly been reserved for the consideration of those whose views were extended further, and whose powers of reasoning had been enlarged by habits of observation and inquiry. Curious and speculative men have likewise made attempts in this way, but often without being sufficiently acquainted with the structure of the parts they were about to consider, and consequently ill informed respecting their relations and connexions with one another. Not contented to reason from those which were most obvious, which might have led to useful knowledge, they have been directed by what best suited their fancy, and have principally attempted the most obscure and intricate. Generation, or the mode of continuing the species, and digestion, or the means of preserving the individual, have been with them the great objects of inquiry; yet it does not appear that they have been very successful. Although digestion, as being one of the most important operations of the animal ceconomy, and most obvious in its effects, supplies a number of facts to assist in ascertaining its powers, little has been hitherto made out towards investigating the various circumstances under which it is performed. The mode of dividing the food for the increase of its surface, in some animals, suggested one method of explaining the process of

* [Spallanzani's observations on digestion appeared first in his work called Fisica Animate e Vegetabile, 12mo. 1782; a translation of which was published in London, with the title ' Dissertations relative to the Natural History of Animals and Vegetables,' in 1784.] | [" Sur la Digestion des Oiseaux," Mem de PAcad. des Sciences de Paris, 1752, pp. 266—307, and pp. 461—495,] OBSERVATIONS ON DIGESTION. 113 digestion ; and the secretion of a juice, which was supposed to have the power of converting vegetable and animal matter into a fluid proper for the purposes of nutrition, furnished another. Both these opinions have had their advocates; and while one party contended for a mechanical power, supposed to exist in the gizzard, the other had recourse to a chemical power, and considered fermentation as the great agent in digestion. They were, however, rather speculative philosophers than practical anatomists, and have frequently been misled with respect to the very facts and observations whose result was to decide the truth of their opinions. What, for instance, does it explain in digestion, that the force of the gizzard of a turkey is found equal to four hundred and seventy-three pounds ? Does it afford a better solution of our doubts than we should derive from determining the force of the mill that grinds the wheat into flour 1 Or, on the other hand, will the most correct idea of fermentation enable us to account for the various phaenomena in the operation of digestion 1 But we can have no very high idea of experiments made by men who, for want of anatomical knowledge, have not been able to pursue their reasoning beyond the simple experiment itself. The great object should have been an endeavour to discover the universal agent in digestion; for the digestive organ is evidently constructed in a different manner in different animals. The me-, chanical power for the division of the food is not universal ; and those gentlemen who consider this power in the gizzard as the immediate cause of digestion, forgot that the same effect was produced in other classes of animals with a different structure of stomach, by means of the grinding teeth. Thus, while the gizzard favoured the theory of the mechanical reasoner, that idea was again destroyed by the membranous structure of the stomach in many animals, which equally supplied the chemist with arguments in favour of the process of fermentation. It is more difficult than those gentlemen imagine, to acquire on this subject information sufficiently accurate to be able to explain a process so complicated as that of digestion. There are in Nature's operations always two obvious extremes; and the mind of man eagerly adopts that which accords with some principle to which he is attached, and with which he is best acquainted, the intermediate connexions and gradations, as being less striking, not so forcibly affecting a superficial inquirer. It happens, unfortunately, that those who from the nature of their education are best qualified to investigate the intricacies, and improve our knowledge of the animal ceconomy, are compelled to get their living by the practice of a profession which is constant employment.0 The only educated men who have leisure are those of the Church, some of whom we frequently find commencing philosophers and physiologists, though they have not had that kind of education which would best direct their pursuit. Experiments, it is true, may be made by men of this description; but these must 114 HUNTER ON THE ANIMAL CECONOMY.

neither be much complicated, nor have any immediate relation to those branches of knowledge with which they have had few opportunities of being acquainted: at best, they will seldom go further than to explain a single fact. To look through a microscope and examine the red globules of blood, to view animalculae, and give a candid account of what they see, are points on which such inquirers may be allowed to indulge themselves ; but it is presumption in them to affect to reason of a science in which they can have but a very superficial knowledge, or to expect to throw light on subjects that they have not taken the previous steps to understand. It should be remembered that nothing in Nature stands alone; but that every art and science has a relation to some other art or science, and that it requires a knowledge of those others, as far as this connexion takes place, to enable us to become perfect in that which engages our particular attention. These strictures are applicable to all those who have made experiments to explain digestion. The effect of the mechanical powers being easily understood, those who considered digestion mechanically have in general explained them justly as far as they applied to the gizzard; but their reasoning went no further, and they supposed these effects to be digestion. Those again who took it up chemically, being little acquainted with chemistry and totally ignorant of the principles of the animal oeconomy, have erroneously explained the operations of the animal machine as subject to the laws of chemistry. The first inquirers into digestion, struck only by the extremes of structure, the gizzard, and membranous stomach, paid no regard to the gradations leading from the one to the other ; which, if properly examined, would have materially assisted them to explain the functions of the stomach. Vallisneri, considering the power of the gizzard in one view only. imagined it would be as liable to be affected by the mechanical powers necessary for digestion as the grain which was to be digested ; therefore supposed the existence of a solvent. But though Vallisneri is entitled to no merit from this idea, as the premises are false, yet this opinion of his set Reaumur to work, and has been the means of bringing several curious facts to light.* The experiments of Reaumur were first made with a view to confute that opinion,

* [In this historical sketch, so rare in the writings of Hunter, of the opinions entertained by previous physiologists on the subject of digestion, the suggestion by Tyson of the existence and use of a solvent or corrodent fluid ou^hAo have had a place. In his Anatomy of a Rattlesnake he observes, "The food, before it can prove aliment, must be comminuted, and broken into the smallest particles; which in these membranous stomachs I can't see how it can be performed but by corrosion. A principal menstruum in doing this I take to be that liquor which is discharged by the glands that are seated, in some, at the beginning of the throat, and are called salival,- or just above the stomach or gizzard of birds, and called the echinus,- or in others in the stomach itself, and called the glandnlos coat, and such I take the inner coat of the stomach of our rattlesnake to be."— Philos. Trans., xiii. 1683, p. 33.] OBSERVATIONS ON DIGESTION. 115 and therefore birds having gizzards were adapted to his purpose. In this pursuit he only attended to such parts of the experiments as best accorded with his own opinion, yet carefully guarded against every possible accident that might affect their accuracy. Had trituration been the immediate cause of digestion, his experiments on the gizzards of birds were unnecessary; since it would have been sufficient to have examined the food after it had been masticated by the teeth of animals who have grinders, the teeth and gizzard answering one and the same purpose. But the circumstance of animals which masticate their food in their mouth having also a stomach, should have taught that there was something more in. digestion than trituration. Reaumur's first experiments were made to ascertain the strength of the gizzard, with its effects, to prove that sharp cutting subtances when swallowed in no way injured its internal coat, and that the common food of the bird was not dissolved when guarded against its action. Yet, after all these proofs, he seems to doubt, and says, " Are we to conclude that grinding alone is sufficient to convert the grain and other aliment into a matter proper for the nutrition of the animal, without undergoing any other preparation? Several reasons seem to oppose this: trituration alone might reduce the grain into a flour ; but flour alone is not chyle." " From the smell of the aliment (taken from the gizzards of birds) are we not led to conclude that it undergoes a fermentation? Tbis smell maybe said to arise from the liquor with which the aliment is mixed ; but is it likely that juices do not dispose to fermentation substances in which it is so easily excited? Fruit and flour, made into a paste, require little more than heat to make them ferment." From these experiments, made with a view to prove that digestion is carried on by trituration, Reaumur was led to suppose a solvent. But as there are some birds whose stomachs do no not seem sufficiently strong to have the power of trituration, he selected the buzzard as being of that kind, and the fittest for the subject of his experiments, from the circumstance of its throwing up whatever is solid and indigestible; therefore, without killing the bird, he could know the result, and repeat the experiment as often as he thought necessary. From the stomach in the buzzard being incapable of trituration, he concluded that a solvent was necessary for digestion; but, to preclude all mechanical effects of the stomach, in his experiments he employed tin tubes filled with meat, which, after the tubes had remained twenty-four hours in the stomach of the buzzard, was reduced to three-fourths of its size, was like threads, and was neither putrid, sour, nor volatile, but insipid. On this effect he made his remarks, which are very pertinent. In another experiment, which was still more accurate and conclusive, he was convinced of the action of a solvent. He then tried the soft bones of young animals, and found they were digested; and that though the hard bones were not acted on so readily, yet, by returning the same bones several times into the stomach, they were digested at last. 116 HUNTER ON THE ANIMAL CECONOMY.

Reaumur was next anxious to know if such birds as were intended by Nature to live upon meat could also digest vegetables; but the result was not so satisfactory. He gave bread to his buzzard, which upon being returned had the appearance of having been chewed. He next tried a piece of ripe pear, after having been twenty-four hours in the stomach, had lost some of its weight, and had the appearance of being boiled or baked ; and thence he concludes that its powers are too weak to digest vegetables so as to nourish the animal. To ascertain the nature of the liquor which had such powers, he tasted the jelly to which the meat and bone had been reduced, supposing that it must be well impregnated with this fluid; but he could only distinguish a bitter or a saltish taste. To have an opportunity of more certainly determining the nature of this solvent, he made his buzzard swallow small tubes filled with sponge, which imbibed fifty grains of this liquor, having the same taste as the jelly, and changing blue paper to a red. He tried the effects of this liquor on meat out of the body, with comparative experiments in water; and after twenty-four hours the meat in the water was become putrid ; but that in the liquor from the stomach was only softened, not dissolved. To see how far the analogy held good in membranous stomachs, he gave two bones to a dog, which'being killed after twenty-six hours, they were found lessened in size, and become as soft as horn. He found that the stomach of the dog did not alter the shape of any of his tubes. He conveyed grass and hay, inclosed in tubes, into the stomachs of ruminating animals, which substances were not digested, but appeared as if macerated. Let us enumerate the experiments and facts made out by Reaumur. The gizzard was not hurt by acting upon glass, which it ground to a powder. The stomach or gizzard had hardly any visible motion. The force of the gizzard was ascertained. The size of the stones found in the gizzard was in proportion to the size of the bird. The stomach of a buzzard digested bone, from which he concluded the gastric juice had a solvent power; but it did not digest bread, although it acted in a slight degree on fruit. He made experiments with the gastric juice. The juice in the ruminating animals' stomachs produced no effect on hay or grass when inclosed in tubes. Reaumur's experiments, although not complete, paved the way for future investigation; and Spallanzani, proceeding on the same ground, has not only confirmed them by his own, but has established several points not completely made out by Reaumur; for in some instances Reaumur gave up the point too soon, especially in the experiments respecting the buzzard's power of digesting vegetables. Reaumur not possessing general knowledge sufficient to direct him OBSERVATIONS ON DIGESTION. 117 '

in his pursuits, was necessarily confined to what he was most master of, the mere making experiments. Being neither an anatomist nor a physiologist, he has not been perfectly just in his description of parts,, having considered the crop and the oesophagus leading from it to the gizzard as two distinct stomachs; but this, however, is only to be set down as a piece of anatomical ignorance, not affecting the subject in the least. Spallanzani is also deficient in his anatomical knowledge ; yet it must be owned that his experiments, as far as they go, are in themselves conclusive; but like all mere experiment-makers, he is not satisfied even with those which are clear and decisive, but multiplies them most unnecessarily, without varying them to elucidate other and essential parts of the same subject. I think we may set it down as an axiom, that experiments should not be often repeated which tend merely to establish a principle already known and admitted; but that the next step should be, the application of that principle to useful purposes. If Spallanzani had employed half his time in this way, and had considered digestion under all the various states of the body and stomach, with all the varieties of food, both natural and artificial, he had employed his time much better than in making experiments without end. The food of animals in general being composed either of vegetables, animals, Or both, and a solvent admitted as an agent in digestion, it only remained to prove, that the effect of the process of digestion was to produce from these various substances an animal matter, similar in all animals who live on such substances. But the application of principles requires more than simply the knowledge of the principle itself, and therefore those who cannot reason from analogy, or draw general conclusions from a few convincing facts, and who require to have every relative conclusion or inference proved by an experiment, must be pleased with Spallanzani; but he must tire even those whom he informs, and much more those who read his works in expectation of something new. To make comparative experiments upon the digestive power, the different animals destined for that purpose should be under similar circumstances as far as relates to digestion ; they should be equal in age, for the growing eat more than the full-grown, and of course digest faster; which point, therefore, can be best ascertained by selecting those in each class of animals which have attained their full growth. They should be equal in fatness, for this makes a very material difference in the powers of digestion in the same animal; and they should be equal in health, a circumstance which, of all others, probably makes the greatest difference in the powers of the stomach. In comparing animals of the same class, the atmosphere should likewise be of the same temperature; for the different classes of animals are variously affected by the same degree of heat. Experiments made upon snakes and lizards in the winter will differ greatly from those made in the summer, while similar experiments made on dogs will have nearly the same result 118 HUNTER ON THE ANIMAL CECONOMY.

in both seasons. Nor will the powers of the stomach be found always equal in the same class. Sleeping animals of the quadruped kind, as hedgehogs, do not digest in the winter, but in the summer only ; therefore the conclusions to be drawn from experiments made respecting the digestive powers in the one, are not at all applicable to those made in the other season. Spallanzani observed that the snake digested food faster in June, when the heat was at 82° and 83°, than in April, when it was only 60°; from whence he concludes, that heat assists digestion; but this heat is not the immediate, but the remote cause of the increased power; heat having produced in the animal greater necessity for nourishment, and of course greater powers, gastric juice was secreted faster or in greater quantity. As a proof that heat does not act as an immediate, but only as a remote cause in assisting digestion, I shall mention the effect it produced upon a hedgehog, the subject of Mr. Jenner's third experiment on the heat of that animal, related in another part of this work. " The hedgehog, while the heat of the stomach was at 30°, had neither desire for food, nor power of digesting it; but when increased by inflammation in the abdomen to 93°, the animal seized a toad which happened to be in the room, and, upon being offered some bread and milk, it immediately ate it. The heat roused up the actions of the animal ceconomy; and the parts being unable to carry on these actions without being supplied with nourishment, the stomach was stimulated to digest, to afford them that supply." Spallanzani also mentions the slowness of digestion in serpents, and* quotes Bomare, who gives an account of a serpent at Martinico, in whose stomach a chicken had remained for three months without being completely digested, the feathers still adhering to the skin.* The truth of this fact I should very much doubt, especially in so warm a climate as that of Martinico, where I must suppose the digestive powers to be constantly required; unless there is in Martinico, as in colder climates, a torpid season,f where the act of digestion is not necessary ; but in that case the serpent would not have swallowed the chicken. At Belleisle, in the beginning of the winter 1761-2, I conveyed worms and pieces of meat down the throats of lizards when they were going into winter quarters, keeping them afterwards in a cool place. On opening them at different periods I always found the substances which I had introduced entire, and without any alteration : sometimes they were in the stomach ; at other times they had

* Bomare, Diet. d'Histoire Nat. f [This conjecture is true; the dry season in some tropical climes is that during which reptiles and insects retire to their hiding-places and become torpid ; they are awakened and called into activity by the showers of the rainy season. The tenrec, a mammiferous animal of Madagascar and the Mauritius, resembling the hedgehog, also sleeps in a state of lethargy from April to November, when the mean temperature exceeds our summer heat.] OBSERVATIONS ON DIGESTION. 119

passed into the intestine; and some of the lizards that were preserved alive voided them towards the spring, with but very little alteration in their structure. So that digestion is regulated by the other actions of the body : warmth requires action suitable to that warmth; the body requires nourishment suitable to that action; and the stomach being called upon, performs the office of digestion. Nothing can show more clearly that the secretion of the gastric juice is increased in proportion to the call for nourishment in the body, than what happened to Admiral Byron and Captains Cheap and Hamilton, when shipwrecked on the west coast of South America, who, after suffering months of hunger and fatigue, were reduced to skin and bone ; yet when they came to good living, Byron thus expresses himself: "He (viz., the governor) ordered a table to be spread for us, with cold ham and fowls, which only we three sat down to, and in a short time despatched more than ten men with common appetites would have done. It is amazing that our eating to that excess we had done, from the time we first got among these kind Indians, had not killed us ; we were never satisfied, and used to take all opportunities, for some months after, of filling our pockets when we were not seen, that we might get up two or three times in the night to cram ourselves. Captain Cheap used to declare that he was quite ashamed of himself." Spallanzani has made several attempts to prove what few will subscribe to, that stones in the gizzards of birds are of no use towards the breaking or grinding down the grain ; and that they are picked up without design. These stones have long been supposed to answer the purposes of trituration, and have been considered as affording assistance to the stomach, in the manner of teeth, and of course as being necessary to the act of digestion. Spallanzani combats this opinion; but as stones are universally found in gizzards, and it was necessary to account for the mode of their being conveyed there, he attributes it to chance. But we find that the gizzards which have most occasion for them, and are most able to use them, are likewise best supplied with them : to corroborate which facts may be added what we observed before, that in the larger gizzards are found the largest pebbles. In a turkey two hundred were found ; in a goose, a thousand ; which could not depend entirely upon chance. In trying whether the stones were of service, Spallanzani introduced tubes, needles, and lancets into gizzards in which there were but very few stones, yet found them broken. In this experiment these substances had been forty-eight hours in the gizzards; whereas in the former experiments, with the same kind of tubes, thirty-six hours was the longest time; in another, eighteen hours; and in another, the breaking of them was begun in less than two hours; therefore the experiments were not perfectly fair, as the times were not equal. What he thinks the most conclusive is, that where he had taken care there should be no stones, the hard indigestible substances were acted upon much in the same 120 HUNTER ON THE ANIMAL CECONOMY.

way as when there were stones; but in this experiment he does not give the time, which is very accurately stated in most of the others. He discovered that the inner surface of the stomach was not hurt by such substances; and indeed it is scarcely possible for the inner coat of the stomach of a fowl to be pierced by such as are even sharp-pointed, the quantity of its motion being so inconsiderable as hardly to make them pass through its inner coat. But the principal cause of their being harmless arises from the motion being lateral, and not pressing perpendicularly to the axis, one surface sliding in a contrary direction to the other, and that not in a straight, but in a circular direction, as will be explained hereafter. In considering the strength of the gizzard, and its probable effects when compared with the human stomach, it must appear that the gizzard is in itself very fit for trituration; we are not, however, to conclude that stones are entirely useless; for if we compare the strength of the muscles of the jaws of animals which masticate their food with those of birds which do not, we shall say that the parts are well calculated for the purpose of mastication ; yet we are not from thence to infer that the teeth in such jaws are useless, even although we have proof that the gums do the business when the teeth are gone. If stones are of use, which we may reasonably conclude they are, birds have an advantage over animals having teeth, so far as stones are always to be found, while the teeth are not renewed. Spallanzani concludes, " That we have at length a decision of the famous question concerning the use of these pebbles, so long agitated by authors; it appearing that they are not at all necessary for the trituration of the firmest food, &c,;" but says, " He will, however, not deny that when put in motion by the gastric muscles, they are capable of producing some effects on the contents of the stomach." Now if we constantly find in an organ substances which can only be subservient to the functions of that organ, should we deny them to be of any use because the part can to a certain degree do its office without them ? To account for pebbles being found in the gizzard, Spallanzani supposes the birds to have picked them up by chance, or not to have distinguished between their food and these stones. But it appears singular that only those which have gizzards should be so stupid ; and he owns that Redi and himself found that birds died of hunger, yet without having picked up more stones than usual, which we might suppose they would have done if they had not had a choice, or could not have distinguished stones from the grain on which they feed. The stones assist in breaking the grain, and by separating its parts in the beginning of the process, and afterwards by rubbing off the surface already digested, allow the gastric juice to come more completely in contact with the whole. It has been said, that the motion of the gizzard is so small as OBSERVATIONS ON DIGESTION. 121 hardly to be observable, and that it cannot be felt by the hand. But as its cavity is very small, and must be capable of adapting itself to the quantity it contains (or it could not possibly grind), much motion is not necessary for the purposes of trituration: a swelling and collapsing, like the motion of the heart, would have no effect. The extent of motion in grindstones need not to be the tenth of an inch, if their motion is alternate and in contrary directions. But although the motion of the gizzard is hardly visible, yet we may be made very sensible of its action by putting the ear to the sides of a fowl while it is grinding its food, when the stones can be heard movingupon one another.* It may be remarked, that the motion of the whole intestinal canal, from the fauces to the anus, is naturally so slow, as not to be excited into quick actions. The food passes slowly along the oesophagus ; and in a man, fluids which might be expected to act even by their own gravity, descend but slowly; yet 1 think we may be certain that the oesophagus has always a regular contraction, and that the lower parts must relax in progression as it contracts above ; so that no position of the body makes any difference in this action. Upon exposing the stomach in living animals it does not appear much agitated or affected, even by being handled or otherwise irritated. The same thing may be observed in the whole track of intestines: and we find that when the fasces are expelled by the action of the gut alone, that the explusion is slow ; the stomach and rectum, however, can be emptied at once; but that is done by the abdominal and other muscles. We know that the action of vomiting is performed entirely by the diaphragm and abdominal muscles ; and we know that by the same action the contents of the rectum can be expelled. Neither is any other power required to empty the stomach in vomiting, these muscles being often capable of forcing the bowels themselves out of the abdomen, and of producing a rupture. It is not necessary the stomach itself should act violently to produce an evacuation of its contents ; nor is it even necessary it should act at all; for the lungs themselves do not act in the least when any extraneous matter is to be thrown up ; and coughing is to the lungs what vomiting is to the stomach.f The

* [Harvey makes a similar observation on birds of prey : "Falconibus, aquilis, aliisque avibus ex praeda viventibus, si aurem prope admoveris dum ventriculus jejunus est, manifestos intus strepitus, lapillorum illuc ingestorum, invicemque collisorum percipias."—Opera Omnia, 4to., p. 208. These investigations by means of the ear relative to the internal actions of animal bodies deserve a place in the history of auscultation.] f [The conclusion which Hunter deduces from philosophical and just analogies, with respect to the share performed by the stomach in the act of vomiting, has not been considered satisfactory, at least if we may judge from the experiments which have subsequently been made with a view to determine that point. But perhaps M. Majendie was not aware of what our illustrious physiologist had written on the subject, as he introduces his experiments to our notice as if the passive state of the stomach in vomiting had never before been suspected : " On a cru long-temps que le vomissement dependait de la contraction brusque et con- 122 HUNTER ON THE ANIMAL CECONOMY. muscles of respiration are the active part in emptying the lungs, and can act both naturally and preternaturally. The muscles of the thorax and abdomen do not act naturally on the contents of the abdomen, but often act preternaturally, producing an evacuation from its viscera. There is this difference in the action of the parts in coughing and vomiting: the cough is performed by the proper muscles of respiration, which are those of expansion, supported by the abdominal, while the diaphragm is passive. Vomiting is performed by the abdominal muscles and diaphragm, while those of inspiration are supporting this action. In coughing the ribs are suddenly depressed, which diminishes the capacity of the thorax; and that the diaphragm may not be allowed to sink down and increase the capacity of the thorax, which would counteract the depressors of the ribs, the abdominal muscles at the same time act, which supports the diaphragm in its place, and probably may by this action assist in bringing down the ribs. To give as much force to this action as possible, the glottis is shut till the action is begun, and then the glottis open instantaneously, which obliges the depressors of the ribs to begin the effort with their full action. The proper muscles of inspiration do not tire so soon in this action as the abdominal, for in violent coughing the muscles of the abdomen become sore. In vomiting these actions are reversed. The muscles of the cavity of the abdomen act. in which is to be included the diaphragm; so that the capacity of the abdomen is lessened, and the action of the diaphragm rather raises the ribs; and there is also an attempt to raise them by their proper muscles, to make a kind of vacuum in the thorax, that the oesophagus may be rather opened than shut, while the glottis is shut so as to let no air enter the lungs. The muscles of the throat and fauces act to dilate the fauces, which is easily felt by the hand, making there a vacuum, or what is commonly called a suction ; so that when all these actions take place together, the stomach is immediately emptied. In violent coughing we find that a kind of mixed action takes place; for although the diaphragm has not acted, yet the stomach is so much squeezed as to discharge its contents; and it affects the diaphragm, which is often thrown into action, and brings on vomiting at the same time; therefore violent coughing palls the stomach. There is reason to believe that the natural motion in all stomachs

vulsive de l'estomac," &c.; and then goes on to detail his notorious experiment on the dog, for whose stomach he substituted a pig's bladder; by which he proved, that when rilled with fluid and put into a situation to be pressed upon, the contents of the bladder would flow out. By dividing the phrenic nerves, and paralysing the diaphragm, Majendie also proved that the abdominal muscles alone were capable of producing vomiting; and by another experiment, he satislied himself that the diaphragm alone was sufficient for that act when all the abdominal muscles had been dissected off, and the peritoneum left entire.] OBSERVATIONS ON DIGESTION. 123 is regular; and I am more inclined to be of this opinion from what takes place in the stomach of animals which are covered with hair, and which lick their own bodies, and of such as feed on whole animals which are likewise covered with hair. In the stomach of the calf, for instance, which licks its skin with its tongue, and swallows whatever is attached to the rough surface of that organ, balls of hair are often found; and on examining their surface the hairs in each hemisphere seem to arise from a centre, and to take the same direction, which is circular, corresponding to what would appear to be the axis of this motion, and resembling what we see in different parts of the skin of animals whose hair takes different turns. This regularity in the direction of the hair, in such balls, could not be produced if there was not a regular motion in the stomach. This motion is also proved in the dog; for I have seen a ball of this kind that had been thrown up from a dog's stomach, where the same regularity in the turns of the hair was very evident and complete. The same motion seems also to take place in the bird kind; and of this the cuckoo is an example, which, in certain seasons living on caterpillars, some of which have hairs of a considerable length on their bodies, the ends of these are found sticking in the inner horny coat of the stomach or gizzard, while the hairs themselves are laid flat on its surface ; not in every direction, which would be the case if there was no regular motion, but all one way, arising from a central point placed in the middle of the horny part, and the appearance on the surface of both sides of the gizzard evidently corresponding.* These two facts prove, in my opinion, a regular circular motion taking place in the gizzard and membranous stomach, and therefore, most probably, something similar is carried on in stomachs of all the various kinds. Indeed this motion in the stomach is so considerable, that when there is no horny defence, we find the coats sometimes pierced by hard pointed substances. Thus, the cows which feed on the grass of bleechinggrounds have their stomachs, especially the second stuck full of pins ; and fish which prey upon and swallow other fish entire, often have their stomachs pierced by the bones. Spallanzani calls the inner coat cartilaginous, whereas, in fact, it is a horny substance, forming an inner cuticle, but differing in some respects from the common cuticle; this horny substance not only differs in structure from the common cuticle, but in its attachment, from cuticle, nails, and hoofs. The cutis where it is covered by such substances, has a vast number of villi on its surface, which pass into corresponding perforations in the cuticle; from this structure of parts, when the cuticle, nails, or hoofs are separated, their inner

* [The appearance is so regular, that this hairy lining of the gizzard has been mistaken, for a natural peculiarity of the cuckoo. In one of these gizzards, which was exhibited at a meeting of the Zoological Society, I found the supposed gastric hairs under the microscope to present the complex structure characteristic of those of the larva of the tiger-moth (Arctia Caja). See Proceedings of the Zool. Soc. 1834, p. 9.] ]24 HUNTER ON THE ANIMAL CECONOMY. surface appears to be full of small perforations, and the cutis from which they have been removed is villous; and these villi are more numerous in some parts than in others, where the sense of touch is required to be delicate or acute. But the inner lining of the gizzard is just the reverse, that surface of the horny substance which is in contact with the gizzard being villous, and when separated, the inner surface of the gizzard appearing perforated. These villi are either the last-formed parts of this horny substance, or are the fibres of which the horny coat is composed. It is probable that this horny substance takes the form of villi that it may be more firmly connected with the gizzard, in which acute sensation is not required. I may remark here, that the experiments made on the digestion of ruminating animals have been very deficient,* arising from this process in them being more complicated than in the stomachs of other animals, and requiring attention to be paid to certain circumstances, which cannot take place in stomachs of only one cavity. The circumstance mentioned by Spallanzani, of ruminating animals voiding the tubes by the anus, shows that the whole food is not necessarily returned into the mouth to be chewed a second time ; for if it were, the tubes would certainly come up likewise, and would as certainly be thrown out of their mouths as improper to be chewed, a circumstance which often really happened. But it was hardly necessary to make experiments to ascertain whether ruminating animals digested meat, when we know that in some cold countries the cattle are fed on dried fish, and most animals eat their own secundines: indeed the circumstance of animals living upon both animal and vegetable food might have taught us that the mode of digesting both (whatever it is) was the same; therefore all that was wanted must have been to discover that mode; except we could absurdly conceive that two different modes might take place in the same stomach at the same time. Spallanzani gives the opinion of authors respecting digestion; and so anxious is he to combat the idea of its being fermentation, that he will hardly allow that fermentation ever takes place in the stomach. That fermentation can go on in the stomach there is no doubt; but when that happens, it arises from the powers of digestion being defective. Milk, vegetables of all kinds, wine, and whatever has sugar in its composition, become much sooner sour in some stomachs than they would if left to undergo a spontaneous change out of the body; and even spirits in particular stomachs, almost immediately degenerate into a very strong acid. I am inclined to suppose that it is the sugar which is converted into spirit, and the spirit into acid ; consequently a glass of brandy, from being much stronger, because less diluted, most probably

* [This deficiency has recently been supplied by M. Flourens, in an elaborate series of experiments made on living sheep, in which fistulous communications had been established between the external surface and the different cavities of the stomach. See Annates des Sciences Naturelles."] OBSERVATIONS ON DIGESTION. 125 contains as much matter likely to become acid as half a pint of wine. In other substances, besides those mentioned above, the fermentative process (unless prevented by that of digestion) appears to begin sooner in the stomach than out of the body. All oily substances, particularly butter, very soon become rancid after being taken into the stomach; and this rancidity is the effect of the first process of the fermentation of oil. Mr. Sieffert has been able to restore rancid oils to their original sweetness, by adding to them their due quantity of fixed air;* the loss of which I consider as the first process in this fermentation, similar to what happens in the fermentation of animal and vegetable substances. Animal food does not so readily ferment in the stomach when combined with vegetables as when it is not; for the vegetables running more quickly into fermentation, preserve the meat from putrefaction. Put a piece of meat and sortie sugar, or bread, into water, and let them stand in a warm place; the bread and sugar will begin to ferment, the water will become sour, and the meat be preserved ; but the acid becoming weaker, as the fermentation advances towards the putrefactive, the meat at last begins to acquire the same putrid disposition.! Yet this last part of the process cannot, I think, take place in the stomach, as a succession of acids will be formed, by which the meat will be preserved sweet till it is digested ; the formation of this acid in the stomach, most probably, not preventing the digestion of those substances which are incapable of being rendered acid. Bread allowed to remain in the stomach of a dog for eight hours is so much changed that it will not run into the vinous fermentation, but when taken out and kept in a warm place becomes putrid; its putrefaction, however, is not so quick as a solution of meat that has been in the stomach for the same length of time. Similar effects are produced when milk and bread are the food administered; and perhaps the gastric juice, when in sufficient quantity, will always prevent the vinous fermentation. Spallanzani's next trials were to determine whether the gastric juice had the power of recovering meat already putrid: a fact which might have been proved by one experiment; for if veryputrid meat is given to a dog, and the dog killed after some time, the meat will be found sweet, and all putrefaction at an end. Therefore his allowing fresh meat to continue a longer or shorter time in the stomach was immaterial, as it could not become putrid. It appears from the above facts that the stomach has not so much power in preventing the acetous fermentation in vegetables as in correcting the putrefactive disposition in animal substances. For although this cannot be certainly known in those who eat both

* Physical and Chemical Essays, by Sir Tobern Bergman. f Of this Sir John Pringle was not aware in making his experiments on this subject. 12* 126 HUNTER ON THE ANIMAL CECONOMY. animal and vegetable food, yet it does not appear that the putrefaction of animal substances, where nothing else is eaten, takes place so quickly in the stomach as the change which is produced in vegetables; the acetous disposition is therefore either stronger than the putrefactive, or it more readily takes place: and indeed the living body shows this sufficiently; for we very often find an acid thrown up, but seldom or never anything putrefactive. It may be admitted as an axiom that two processes cannot go on at the same time in the same part of any substance; therefore neither vegetable nor animal substances can undergo their spontaneous changes while in the act of being digested, it being a process superior in power to that of fermentation. But if the digestive power is not perfect, then the vinous and acetous fermentation will take place in the vegetable, and the putrefactive in the food of those animals which live wholly on flesh ; although in the last I imagine but very seldom. The gastric juice, therefore, preserves vegetables from running into fermentation, and animal substances from putrefaction ; not from any antiseptic quality in the juice, but, by making them go through another process, preventing the spontaneous change from taking place. In the greater number of stomachs there is an acid, even although the animal has lived upon meat for many weeks; but as this is not always the case, we must suppose it is only formed occasionally. Whether the stomach has a power of immediately secreting this acid, or first secretes a sugar which afterwards becomes acid, is not easily ascertained;* but I should be inclined to suppose, from analogy, the last to be the case: animals in health seeming to have the power of secreting sugar; for we find it in the milk, and sometimes in the urine, in consequence of disease. Acid sometimes prevails in the stomach to so great a degree as to become a disease, attended with very disagreeable symptoms; the stomach converting all substances which have a tendency to become acid into that form. To ascertain whether there was an acid naturally in the stomach the most satisfactory mode was to examine the contents before the birth, when the digestive organs arc perfect, and when no acid could have been produced by disease, or anything that had been swallowed. Accordingly, in the slink-calf, near the full time, there was no acid found in the stomach, although the contents had the same coagulating powers with those of animals who have sucked. As we find stomachs possessed of a power of dissolving the

* [The singular case of the man with an external fistulous communication with the stomach, detailed by Mr. Beaumont, who has so ably availed himself of the circumstance to elucidate several obscure points in the process of dio-estion, has afforded the means of determining this question. The stomach in its°empty and inactive state contains no gastric juice; but when mechanically stimulated, as by touching the inner surface with the bulb of a thermometer that secretion is immediately poured out, and manifests the usual acid properties. (Beaumont: " Experiments and Observations on the Gastric Juice, and ou the Physiology of Digestion.")] oJ OBSERVATIONS ON DIGESTION. 127 whole substance of a bone, it is reasonable to suppose that its earth is destroyed by the acid in the stomach. The stomach appears not only to be capable of generating an acid, but also to have the power of producing air: which last effect, I believe, arises from disease. It is not easy to account for the formation of this air; yet as the stomach is a reservoir for substances disposed to ferment, it might reasonably be supposed to arise from the food going into that process. But this, in my opinion, will not account for the vast quantity of air frequentlythrown up from the stomach, even where food has not been swallowed for a considerable time, and where digestion appeared to have been completed. For we must conclude this process to have been completed, if the food was not found to have disagreed with either stomach or bowels, arid that the stools were good. When the gout falls on the stomach the quantity of air thrown up is often immense, and the same thing may be observed in some cases commonly called nervous ; yet the process of digestion will not account for this formation of air, as no air is to be found in healthy stomachs ;* neither is it to be accounted for from a defect in digestion, as that would probably be productive of wTorse consequences. I am inclined to believe that the stomach has a power of forming air, or letting it loose, from the blood, by a kind of secretion. We cannot, however, bring any absolute proof of this taking place in the stomach, as it may in all cases be referred to a defect in digestion; but we have instances of air being found in other cavities, where no secondary cause can be assigned. I have been informed of persons who have had air in the uterus or vagina, without having been sensible of it but by its escaping from them without their being able to prevent it; and who, from this circumstance, have been kept in constant alarm lest it should make a noise in its passage, having no power to retard it as when it is contained in the rectum. This fact being so extraordinary made me somewhat incredulous, but rendered me more inquisitive, in the hope of being enabled to ascertain and account for it; and those of whom I have been led to inquire have always made the natural distinction between air passing from the vagina and by the anus: that from the anus they feel and can retain, but that in the vagina they cannot; nor are they aware of it till it passes. A woman, whom I attended with the late Sir John Pringle, informed us of this fact, but mentioned it only as a disagreeable thing. I was anxious to determine if there were any communication between the vagina and rectum, and was allowed to examine, but discovered nothing uncommon in the structure of these parts. She died some time after; and, being permitted to open the body, I found no disease either in the vagina or uterus. Since that time I have

* In all my experiments on digestion, in dogs, I have never been able to detect any air in the cavity of the stomach. 128 HUNTER ON THE ANIMAL CECONOMY.

had opportunities of inquiring of a number of women concerning this circumstance, and by three or four have been informed of the same fact, with all the circumstances above-mentioned. How far they aie to be relied upon I will not pretend to determine. I have likewise found air in the cellular membrane in gunshot wounds, that had passed some way under the skin, without being able to account for its being there by any mechanical effect of the ball. That air is either formed from the blood, or let loose by some action of the vessels, both naturally and from disease, is an undeniable fact. We find air formed in some fishes, to answer natural purposes; for in those whose air-bladders do not communicate externally (many of which there are) we must suppose it to have been formed there. We also find it in animals after death; and I have a piece of the intestine of a hog which has a number of airbladders in it. Mr. Cavendish was so kind as to examine this air, and he found " it contained a little fixed air; and the remainder not at all inflammable, and almost completely phlogisticated." I have often seen such vesicles on the edges of the lungs; but these may be supposed to have been a kind of aneurismal air-cells filled from the trachea, and are circumscribed and impervious, so that in the state we find them they have no communication with the external air. In one instance I have discovered air in an abscess, which could not have been received from the external air, nor could it have arisen from putrefaction. The case is as follows: A lady, about forty years of age, had been afflicted with complaints in the bladder and parts connected with it. From the symptoms, her disease was supposed by some to be the stone, though upon examination no stone was found ; and she had also an umbilical hernia, for which I had been consulted. She grew gradually worse, and from being lusty, became a thin woman. A small tumour appeared in the groin, and the skin over it became red, similar to an abscess when the matter is beginning to point externally; but before her death this subsided. A few days before she died I was desired to examine a swelling on the lower and ri<*ht side of the belly, extending nearly from the navel to the spine of the ilium on the right side. It was tense, evidently contained air, and could be made to sound almost like a drum. It had come on within a few weeks, and I was puzzled to account for it, there being clearly no connexion between that tumour and the umbilical hernia. I was inclined to suppose it to be a ventral hernia, containing the caecum and part of the colon, filled with air; but as she had stools, as there were no symptoms of a strangulated gut nor any uneasiness in the bowels, as I could not make the air recede, but felt it as if confined to that part, I own I could form no conjecture what the case really was. The woman dying in a few days, I was permitted to examine the body. That I might not interfere with the tumour, or umbilical hernia, I made an opening into the abdomen on the right side of the hnea alba, and on examining the cavity of the abdomen, found everything natural, except a small portion of the epi- OBSERVATIONS ON DIGESTION. 129 ploon adhering to the inside of the navel; the parietes of the abdomen corresponding with the tumour being in a natural state. On pressing the tumour by the hand, air was heard to make its escape; whether by the vagina or anus was at first doubtful; but on examining with more attention, it was discovered to come from between the labia. I next opened the tumour externally, and let out the air, which was not in the least putrid, and was contained in a sac tolerably smooth on its inside, made up of compressed cellular membrane, the abdominal muscles and tendons forming the posterior surface, which extended as low as the inferior edge of Poupart's ligament. The contents of the abdomen were tolerably sound; but when I inspected the viscera contained in the pelvis, they were found adhering to each other; the bladder to the body of the uterus: the broad ligaments and ovaria to the uterus; and on examining these adhesions, I discovered a cavity between the bladder, uterus, and vagina, on the right side, something like an abscess. From the right side of this cavity there was a canal ascending to the brim of the pelvis, in the course of the round ligament, as far as to the going out of the iliac vessels, which it seemed to accompany; and this canal, when it passed from behind Poupart's ligament, communicated with the tumour above mentioned. I then endeavoured to discover if there were any communication between the rectum and the abscess, but could find none, the gut appearing to be quite sound. Having removed the whole contents of the pelvis, with the canal leading to Poupart's ligament, and the ligament itself, with such of the abdominal muscles as composed part of the sac, I found both the rectum and the vagina perfectly sound. The uterus had a polypus forming on its inside; neither the rectum nor uterus had any connexion with the abscess; but there was a small communication between the abscess and the bladder, that portion of the bladder which made part of the abscess being very much diseased. From this history of the appearances of the tumour before death, and the particular account I have given of the dissection, the reader may be able to draw his own conclusions relative to the origin of the air. It certainly appeared to have been formed in this bag; and it was only towards the latter end of her life that it could have made its escape into the ca vity of the bladder, for it was not possible to squeeze the air out of the tumour when I first saw her ; but just before death it became more flaccid. It could not be formed or let loose, in consequence of putrefaction, for the air itself was free from any smell; and although the cavity between the vagina and bladder had on its internal surface the irregular ulcerated appearance of an abscess, yet that on the abdomen had not, was tolerably smooth, and had rather the appearance of having been formed in consequence of some foreign matter accumulating there. This circumstance, of an animal having the power of forming air, or separating it from the juices by a kind of secretion, appears 130 HUNTER ON THE ANIMAL CECONOMY. at first view to be supported by the experiments of Dr. Ingenhousz.* The Doctor observed, that when we immerse our bodies " in a cold or warm bath," or "by plunging the hand and arm even in cold water," globules of air soon appear upon the skin; and to be certain of the air coming from the body, he took all the necessary precautions to prevent the external air being carried into the water along with the body (which would certainly be a consequence if the body or part were immersed quickly, or when dried). But although his experiments seem to prove this opinion, yet I imagine there is a circumstance the Doctor did not attend to at the time, which renders them very fallacious; for he did not consider that water for the most part contains a great deal of air; therefore the globules of air might as readily come from the water as from the body, which makes it necessary to ascertain, by experiment, from whence the air comes which is attached to the body when immersed in water. Water takes up air in proportion to its coldness, until it loses the property of water, and becomes solid : upon this principle we may account, for globules of air being found attached to the skin when a part of the body is immersed in water colder than itself; for when we immerse the whole body we increase the heat of the water, especially that next to the skin; and if we immerse only a part, as an arm, it being commonly in a smaller quantity of water, the water immediately surrounding it is also warmed. As a proof that it is the air from the water, and not from the surface of the body,f it matters not what the substance is that is immersed if it is but warmer than the water; for a piece of iron, heated to about 150°, immersed in water about 70°, will warm the water in contact with it so as to make it part with its air. This effect of heat is further proved by making another trial, with only this difference, that the iron be ten degrees colder than the water; in that case little or no air will be separated, and of course no bubbles observed. The bubbles of air do not appear to arise entirely from the degree of warmth of the water, but also in some measure from a solid body being immersed in it, that seems to have a power of attract-

* Experiments upon Vegetables, proving their great power of purifying the common air, &c. t " Count de Milly, in the Berlin Transactions for the year 1777, published experiments to show that there is an excretion of air, or, as it is termed,' an aerial transpiration,' from the whole surface of the human body while it remains in warm water; but Dr. Pearson found, on repeating these experiments, that there was no appearance of aerial bubbles on the surface of the cuticle during bathing in warm water that had been previously boiled, so as to expel the air usually mixed and united to river and spring water. The human body, when immersed in the bath at Buxton, and kept at rest in it for some time, was covered with air-like bubbles; but these bubbles appeared in the same manner on any solid body whatever that was placed in it. It is therefore supposed that the attraction to the human body of the air, commonly suspended in water, especially when heated to the temperature of a warm-water bath, has been mistaken for an excretion of air from the cuticle." OBSERVATIONS ON DIGESTION. 131 ing the air, whose affinity to the water is now weakened by heat; for simply heating the water to the same degree will not separate the air, as we find that no bubbles are then produced. The power » of attracting the air appears therefore in some sort to depend upon the solidity of the body immersed; at least bodies have a greater number of bubbles in proportion to their solidity ; for upon making comparative experiments between iron, stone, wood, and cork, the air separated from the water upon the surface of the iron and stone is in considerable quantity; that upon the wood very small, and scarcely any at all upon the cork. As these observations on the generation (or secretion) of air in cavities seemed to have a connexion with the present inquiry, I thought they might properly enough be introduced here ; but I shall content myself with having mentioned the circumstance, and pursue the subject of digestion. To determine with absolute certainty in what particular portion of the canal this important process of digestion is performed, is perhaps impossible; but there is the greatest reason to believe that it is principally carried on in the stomach, with a little variation in different animals. We may venture to affirm that it does not at all take place in the long and contracted oesophagus of the quadruped, the secretion of that part being a slimy mucus, possessed of no power similar to that of the gastric juice, but only intended to facilitate the passage of the food into the stomach. Neither has the mucus secreted in certain parts of the oesophagus of birds, as in the crop of those which have one, any digestive power; while, on the contrary, we find the lower end, which is extremely glandular, to be capable of secreting a juice with all the properties of the gastric ; and that passing into the cavity of the stomach becomes a substitute in this class of animals for the deficiency of the secretion of the stomach itself, which in some is lined with a horny substance, and in others with a cuticle. Even in birds the seat of digestion is chiefly in the stomach, the juice secreted in the lower part of the oesophagus passing into that cavity; and the mucus secreted by the other parts of the oesophagus, as in the crop of those which have one, has no such power. But if any digestible substance should be retained in the oesophagus, as may happen in many of those which swallow whole animals, digestion may even go on in its inferior portion. In the gull and heron, which take down snakes and fish entire, the tails may remain in the oesophagus till the head is digested in the stomach ; and in such cases the tail itself may be acted upon in that situation. As a further proof that digestion is carried on principally in the stomach, let us observe what happens to the yolk of an egg in the bird newly hatched. The yolk is not in the least consumed in the time of incubation, but appears to be reserved for the nourishment of the chick between the time of hatching, and its either being supplied with food by its parents, or being able to procure it for itself: for we find, that although the yolk passes into the gut at 132 HUNTER ON THE ANIMAL CECONOMY. some distance from the stomach, yet it is carried up to the stomach to be digested ; and I have even seen it in the crop, being retained there till wanted. In those animals whose stomach consists of several cavities, the precise place where digestion is carried on has not been ascertained. I think, however, that in the ruminating class, in which it has four cavities, it may be set down as a fact that digestion goes on in the fourth, which is best proved by feeding the animal with a substance that does not require any kind of preparation for digestion, such as milk. If a calf be killed about half an hour after it has sucked its mother, we shall find the whole milk in the fourth cavity firmly coagulated, and formed into a ball, while the first, second, and third cavities contain only such food as requires mastication, or what other preparation is necessary to fit it for digestion. Such animals have the power of conveying the food from the oesophagus, either to the first or fourth cavity, according to the nature of the food; and for this purpose there is a groove leading directly from the oesophagus to the fourth stomach, which I suppose can be converted into a canal when wanted. It is possible that digestion may likewise be carried on in the duodenum, especially in its upper part^if either the intestine secretes the same juice with the stomach, or that some of the gastric juice and part of the food have passed into the intestine before it has been completely turned into chyle.* Although the stomach is the seat of digestion, it is not solely appropriated to that purpose; and in many animals these organs are not to be considered as only a digesting bag or bags, but in part as a reservoir for food. This is most remarkable in the ruminating animals, where the first stomach or bag is merely a reservoir, and in this respect analogous to a crop. It is the same in the porpus, and, I believe, in most animals of this class; althouo-h it cannot be supposed that those return the food who have not the power to masticate. In some animals which do not ruminate there is not the same necessity for distinct pouches, the stomach consisting either of one bag singly, or of stomach with appendages, as in the peccari. But the whole organ is not endowed with the property of secreting the gastric juice, there being a part whose structure is very different from that appropriated to digestion, and covered by

* [This conjecture is confirmed by the observations of Tiedemann and Gmelin, who found that when any vegetable fecula passed the pylorus unaltered it was converted in the duodenum, as in the stomach, into sugar and amydine. Majendie attempted to subject this question to direct experiment, but failed from not having insured the continuance of the substance experimented on in the necessary situation. He found, on introducing a piece of raw flesh into the duodenum of a healthy dog, that in an hour it had been carried to the rectum : its weight was slightly diminished, but there was no other change than a discoloration of its surface. In another experiment he fixed a morsel of flesh in the small intestine with a thread; after the lapse of three hours it had lost about half its weight: the fibrin had been principally acted upon ; what was left was entirely cellular, and extremely foetid. See Precis Elementaire de Physiologie, ii. p. 114.] OBSERVATIONS ON DIGESTION. 133 a cuticle, as in the first, second, and third stomach of the ruminating animals and in the first stomach of the porpus. The peccari, the common hog, and the rat, are likewise instances of this; and the same circumstance takes place, in a smaller degree, in the horse. This increase in the cavity of the stomach, beyond what is necessary for digestion alone, is peculiar to the animals that take in more food than is immediately wanted, or whose food is of a nature which requires a certain degree of preparation prior to digestion. The crop of the eagle, and perhaps the first stomach of the porpus, are of the first kind; the crop in the gallinaceous fowls, and the first stomach in ruminating animals, of the second.* It is the disposition of such animals to fill these cavities; and the quantity which they are capable of containing makes them seldomer require to be filled; it is probable, likewise, that it is the sensation excited by this fulness which gives satisfaction to the animal, and takes off the further desire for food, an effect similar to what is produced in other animals from filling the stomach itself; and these having no such provision, are longer and oftener employed in pursuit of food. I should be apt to consider the power of the gastric juice to coagulate milk, and some other animal mucilages,! as a test of the stomach being the seat of digestion; for although milk may be coagulated by other substances, yet when found in that state in the stomach it is probably for the purpose of digestion, milk and many other natural substances requiring to be coagulated before they can be digested. I have found this coagulating power in the stomach of every animal that I have examined for that purpose, from the most perfect down to reptiles;J and in the appendages which I have

* [According to this difference in their functions, we find that the crop of the eagle ie relatively smaller than that of the fowl, and the passage of its contents to the stomach is more direct and easy. The first stomach of the porpus is still smaller in comparison with the rumen of the sheep; and besides acting as a storehouse for the food, digestion goes on in it to a considerable extent. This is effected, not by secretion from its own parietes, which, as Hunter observes, are lined with a cuticle, but most probably by the gastric juice .regurgitated into it from the second stomach, which is highly glandular. The flesh offish is found separated from the bones, and these in different stages of softening, in the first stomach ; indeed, the construction of the aperture of communication between the first and second stomachs of the porpus is such,' that food can pass into the latter only in a very comminuted state.] f Milk is the substance commonly known to be coagulated by the gastric juice ; but I find that it has also the same power over the white of an egg. Give to a dog some raw egg, and kill him half an hour after he has swallowed it, the egg will be found coagulated in his stomach, as if boiled. The crystalline humour in the stomachs of fishes is likewise found coagulated. X [By " reptiles " there is reason to believe Mr. Hunter meant' creeping things,' as insects and worms. The ' Replilia ' of modern naturalists he invariably calls by the Linnsean name 'Amphibia,' or by his own term, 'Tricoilia.' In the Introduction to the Series of Digestive Organs, (Phys. Catalogue of the Hunterian Collection, vol. i.) he says, "In some reptiles the teeth are placed in the oesophagus," alluding to preparations of a Nereis ; and in a manuscript, published in 134 HUNTER ON THE ANIMAL CECONOMY.

considered as only reservoirs preparatory to digestion, (as the first stomach in the ruminating animal, and the crop in birds,) 1 have discovered no such power. Yet it is not the digestive power which coagulates those substances, complete coagulation taking place even where digestion does not at all go on.* This is evident every day in children who suck, and who have diseased stomachs ; for we see them throw up the milk coagulated, and discharge it undigested by stool. A very remarkable instance occurred in a child that had lost entirely the power of digestion, yet the milk taken down came away strongly coagulated, some even as firm almost as cheese; which seems to show that the coagulating power is seldom wanting, although the other may. The gastric juice is a fluid somewhat transparent, and a little saltish or brackish to the taste; but whether this is essential or only accidental is not easily determined. Indeed there are very few of our secretions which have not some salt in them; it being found in the tears, the saliva, the secretion of the glans penis, of the glands of the urethra, and in the first and the last milk secreted in the udders of animals. I am not inclined to suppose that there is any acid in the gastric juice as a component or essential part of it, although an acid is very commonly discovered, even when no vegetable matter has been introduced into the stomach.f The acid may be increased in some

the same volume of the Physiological Catalogue, there is proof that he experimented on an insect with especial reference to the seat of the digestive power. After detailing the peculiarities of the digestive organs in the fle3h-fly (Musca vomitoria), he observes: " The bag belonging to the first-described canal is to be considered a craw or crop, viz., a reservoir for the food to be ready for digestion ; and as the abdomen contains almost every internal part of the animal, it is obliged to be situated in this cavity. That it is a reservoir for food I proved by experiment: I kept some of these flies fasting for some time: I then gave them milk, which they drank readily; and when I thought they had filled their bellies, I put them into spirits, which assisted in coagulating the milk wherever it might be. On opening the abdomen, I found this bag full of curd and whey, as also some in the stomach. I kept a fly for twelve hours without food, and then gave it milk, and killed it, and found no milk in the crop, but it had got through almost the whole tract of intestines : here the animal had immediate occasion for food, therefore the milk did not go into the crop. This experiment at the same time shows that, probably, every part of the intestines digest, for the stomach makes no distinct ba<*."] * [Or rather the digestive power may be equal to the coagulation, but not to the completion of the digestion of the coagulable substances.] t The only trial to which I ever put the gastric juice was with the syrup of violets, to ascertain if it was acid ; and in many of the trials the colour of the mixture was changed to red. But it is necessary, for the accuracy of the experiment which is J;o determine this fact, that the animal should not be fed upon vegetables for some time before the trial is made, these being liable in some degree to become sour; therefore it is hardly fair to make the experiment on the contents of the stomach of animals who live upon vegetables. In many trials of this kind we may be deceived, and led to suppose an alkali; for certain animal secretions being of a yellow cast, when such are mixed with the svrupof violets the mixture is changed to a green. The truth of the experiment may, however, be known by adding a little acid ; for if the green has been produced merely by OBSERVATIONS ON DIGESTION. 135 diseases, and in others the disposition to form it may be destroyed, which may be the reason why, by a kind of instinctive principle, many girls are fond of eating sour fruit and of drinking vinegar; while others, on the contrary, from a different cause, often eat chalk, lime, and other substances of that sort. But the acid not being always found, it is not yet determined on what occasions it is formed, or in what manner it is destroyed. The process of digestion differs from every other natural operation in the change it produces on different bodies; yet it is by no means fermentation, though it may somewhat resemble it. For fermentation, a spontaneous process, is that natural succession of changes by which vegetable and animal matter is reduced to earth; therefore must be widely different from digestion, which converts both animal and vegetable substances into chyle, in the formation of which there cannot be a decomposition similar to fermentation. Digestion is likewise very different from chemical solution, which is only a union of bodies by elective attraction. But digestion is an assimilating process; and in this respect is somewhat similar in its action to that excited by morbid poisons. It is a species of generation, two substances making a third; but the curious circumstance is its converting both vegetable and animal matter into the same kind of substance or compound, which no chemical process can effeci. The chyle is compounded of the gastric juice

a mechanical mixture, it will become immediately a scarlet, by being then a mixture of red and yellow ; but if the secretion is not only of a yellow colour, but of an alkaline nature, it will also continue green; and by adding a little more acid than what saturates the alkali the colour will then become orange.a a [Various opinions have been entertained as to the acidity of the gastric juice. Spallanzani believed it to be a neutral fluid. Carminati could detect no acid in the gastric juice of carnivorous animals and mixed feeders, but found it to exist in that of vegetable feeders. (Ueber die Natur des Magensaftes, Wien, 1785.) Helm, who examined the gastric juice in a patient with a fistulous opening in the stomach, also states that it contains no sensible acid. (Zwei Krankengeschicten, Wien, 1803.) The same cause of error has probably operated in each of the preceding cases, viz., not making a sufficient distinction between the ordinary mucous secretion of the stomach and the peculiar fluid which is poured out from the stimulus of the contact of food, or any innutritious substances. In the experiments of Tiedemann and Gmelin the ordinary secretion of the stomach in fasting horses and dogs was found to be almost neutral, or very slightly acid; but on stimulating the surface by means of stones, (by which any cause of error from a change of fermentable substances, as alluded to by Hunter, was avoided,) then the secretion manifested unequivocally the presence of acidity. Beaumont has more fully established the acidity of the gastric juice in the work before quoted. He observed in the man with gastric fistula that the gastric juice was poured out from numerous minute clear points or papillae. It is a clear inodorous fluid, with a somewhat salt and very marked acid taste, like that of thin mucilage which has been soured with muriatic acid. It dissolves in water, wine, and alcohol; slightly effervesces with alkali; decomposes slowly, and retards the decomposition of animal matter. Saliva imparts to the gastric juice a blue colour and a frothy appearance. Chemical analysis shows the gastric juice to contain both the muriatic and acetic acids, alkaline phosphates, muriate of soda, magnesia, and lime, and an animal matter which is soluble in cold but not in hot water.] 136 HUNTER ON THE ANIMAL CECONOMY.

and digestible substances when perfectly converted ; and it is probable that the quantity of gastric juice may be nearly equal to that part of the food which is really changed into chyle. If so, it demonstrates the necessity of a very quick secretion, to supply a quantity so very considerable; but with this advantage, that it is not lost to the constitution. The progress of the conversion of food into chyle may be often seen in the stomach of animals at different times after feeding. Fishes are good subjects on which to make observations for this purpose, as they swallow their food whole; and as that food is commonly fish, and often too large to be completely admitted into the stomach. As they do not masticate their food, it is not adapted to the cavity of the stomach ; and therefore part of it is often found lying in Ihe oesophagus; a circumstance by which the comparative progress of digestion is rendered more obvious. It may also be well observed in the stomach of a dog, in which the whole quantity taken has been swallowed at once. In the great end the food will be but little altered; towards the middle, more; and towards the pylorus it will be similar to what is found in the duodenum.* From the structure of the stomach in ruminating animals they are badly adapted to assist our inquiries on this subject, because metallic balls, or whatever is swallowed in so hard and solid a form as to be unfit for digestion, requiring to be j*uminated, will often be thrown out when returned into the mouth for that purpose ; or it may lie a long time in the first stomach without being either thrown up or passed into the fourth, as I have frequently seen; therefore the chance of its getting into the fourth stomach in a proper time to fit it for the object of an experiment being very uncertain, no great light can be derived from trials made on animals of this class. Live or fresh vegetables, when taken into the stomach, are first killed, by which a flabbiness in their texture is produced, as if they had been boiled ; and then they can be acted upon by the gastric juice. Meat appears to undergo no change as preparatory to digestion, but at once to submit to its union with the gastric juice ; for, after having been acted upon, it seems first to lose its texture, then becomes cineritious in colour, next gelatinous, and last chyle. The first change made upon milk and some other secretions, as the yolk and white of an egg, is coagulation; after which the gastric juice begins to acquire a power of uniting with them. The first change which is produced on animal substances out of the body, either by being exposed to heat or by becoming spontane-

* [The cardiac and pyloric portions of the stomach possess the digestive power in very different degrees, it being much more energetic in the latter. In the stomachs of Carnivora and Rodentia the two portions are commonly found divided hya constriction; and the same hour-glass contraction of the stomach is occasionally met with in the human subject. See Sir E verard Home, Phil. Trans. 1817. p. 347.] OBSERVATIONS ON DIGESTION. 137 ously putrid, is similar to the second of the three changes which takes place in digestion; and is only preparatory to the complete change, whether that be digestion or putrefaction. It appears from many experiments that the digested or animalized part, when carried into the intestine, is attracted by the villous coat, or clings to it as if entangled among the villi; while the excrementitious part, such as bile, is found lying unconnected in the gut, as if separated from the other.* The food of animals in general consists of vegetable or animal substances; and vegetables seem intended to support one class, with a view to its being the food of another. Although there are classes of animals intended to subsist on each particular kind of food, yet they do not all invariably keep to the same kind in every stage of life, many being nourished by animal food when young that afterwards live on vegetables ; which circumstance will be more fully discussed while treating of the first food of pigeons. All stomachs do not equally digest the same substance, although it be their natural food. The caterpillar digests the expressed juice, but not the substance; while other animals are capable of dissolving nearly the whole. Some animals, as the common cattle, can feed on a variety of vegetables, although they may have a preference ; but there are others that will hardly eat of more than one kind. Of this last sort are insects in general, and the silkworm will scarcely touch anything but mulberry leaves; but I believe those that live upon animal food are not so restricted in their choice. It is probable that all animal and vegetable substances are equally capable of being digested, if equally soft in their texture; but some being much firmer in that respect, and others also united with indigestible matter, as the earth in bones, more strongly resist the powers of the gastric juice; therefore mastication and trituration become necessary to bring them to a similar consistence. But substances may be rendered too soft, for a fluid is difficult of digestion ; and we may observe, that Nature having given us very few fluids as articles of food, to render these few fitter for the action of the digestive powers, a coagulating principle is provided to give them some degree of solidity.f It is not easy to assign a reason why * [In chylification, the alkaline principles of the bile combine with the acids which the chyme has received in its formation in the stomach, and the albuminous or chylous principles are developed and attracted by the villi; while the resinous parts of the bile, combined with the exerementilious particles of the chyme, are more or less completely separated. The most characteristic change which, according to Prout, takes place in the intestine is the conversion of part of the chyme into albumen, which happensfcven when no albuminous matter was originally contained in the food or formed in the stomach.] f The circumstance of the crystalline humour, which is solid, being coagulated prior to its bei»<r digested, renders it probable that all animal substances go through that process" and that the loss of texture which they undergo arises from coagulation.3

a [This coagulation happens to all animal substances which contain albumen; but can hardly be considered, Dr. Prout observes, " to be essential to the subse- 138 HUNTER ON THE ANIMAL CECONOMY.

fluidity should be unfavourable to the process of digestion, more especially as it seems essential to those of fermentation and chemical solution. The requisite degree of solidity I should suppose to be that of curd, or what is produced by the coagulation of animal mucilages, as of the white of an egg. But this is only supposition, founded on the idea that Nature's general principles are right, and all the corresponding parts adapted to one another, except when monstrous, either in form or action. Mastication is the effect of a mechanical power, produced by parts particularly provided for that purpose, which are of various kinds, fitted for that sort of food on which the animal is by Nature intended to live, and may be imitated with equal advantage by many other pieces of mechanism. The masticating powers are of three kinds. The first is that which merely fits the substance for deglutition, as in the lion and many other carnivorous animals; and which, in the ruminating tribe, renders the food fit to be swallowed, that it may undergo such preparation in the first stomach as is necessary before it is further masticated for digestion. The second is that which not only fits the food for deglutition, but exposes it to the action of the gastric juice, by breaking the shells or husks in which the nourishment is contained, and in which it would be defended from the powers of digestion. And the third is that which divides and bruises the food before it is received into the stomach ; which mastication is of considerable service, by producing a saving in food.* The husk of the seeds of plants, although a vegetable substance, appears to be indigestible in its natural state. Whether this arises from the nature of the husk itself, or from its compactness, I am not quite certain, but am inclined to suppose the last, as we find the cocoa, which is only a husk, to be digestible when ground to a powder and well boiled. We know likewise that cuticle, horn, hair, and feathers, although animal substances, are not affected, in the first instance, by the gastric juice; yet if reduced in Papin's digester to a jelly, that jelly can be acted upon in the stomach: we must therefore suppose that a certain natural degree of solidity in animal and vegetable substances renders them indigestible. This compactness in the husk seems to be intended to preserve, while under ground, the farinaceous part of the seed, in which the living principle is placed, the husk having probably no other power of resisting putrefaction than what arises from its texture ; but whatever may be the use of the husk, it must be connected with the vegetative process of the plant. The same purpose of preservation is probably answered by the shells ofall ova. Although husks are not capable of being dissolved in the gastric juice, they allow of transudation, and that the seed is in some degree affected by it is known

quent process; for gelatin, a staminal alimentary principle, nearly resembling albumen in its composition, undergoes, under similar circumstances, no such solidifying change. (Br. Tr., p. 494.)] * [Blumenbach has well suggested that the vitality of the 6eeds is thus destroyed and they are made subject to the influence of the gastric juice.] OBSERVATIONS ON DIGESTION. 139 by its swelling in the stomach; yet it can only take up a certain proportion of it, and that not sufficient to convert it into chyle, the gastric juice having no power of action upon the husks themselves. Therefore we see grain of all kinds, when swallowed whole, pass through entire, though swelled ; and even the kernels of some nuts, as chestnuts, are not digestible when eaten raw. The essential oils of vegetables and animals are indigestible; but being soluble either in the gastric juice or chyle, they become medicinal, from their stimulating powers. The essential oil of vegetables, but more particularly that of animals, seems to pervade the very substance of those animals whose food contains much of this oil. Thus, we find sea-birds, whose constant food is fish, taste very strongly of fish; and those who live on that kind of food only during certain times of the year, as the wild duck, have that taste only at such seasons. This fact is so well known that it was hardly necessary to put it to the test of an experiment; yet I took two ducks, and fed one with barley, the other with sprats, for about a month, and killed both at the same time : when they were dressed, the one fed wholly with sprats was hardly eatable, it tasted so strongly of fish. Although bones are in part composed of animal substance, and so far digestible, yet they require stronger powers to digest them than common meat, from the animal substance being guarded by the earth. Thus, the animal part of a bone is less easily soluble in an alkali than flesh, or than even the animal part when deprived of its earth by an acid ; nor will a bone, being guarded by the calcareous earth, submit to putrefaction so readily as meat; therefore animals which live upon others, and swallow them whole as the heron, digest bone with more ease than the crow or magpie, that are not accustomed to swallow bones, but commonly pick the flesh only. The degree of ease or difficulty with which substances are digested, will not only arise from a difference in solidity, but from a difference in the structure of the parts themselves; brain, liver, muscle, and tendon, being digestible in the order here put down. There is not only a difference in the degree of facility with which the various kinds of natural food are digested, but these can also be made to undergo changes by art, which render them still more easy of digestion; for it appears from my experiments that boiled and roasted, and even putrid meat, is easier of digestion than raw, which, in the two first, may be supposed to arise from their juices being coagulated; but the same reason will not hold good with regard to the putrid.* A raw egg is thought more easy of diges-

* [From the various experiments instituted by Sir Astley Cooper on the digestibility of different substances, it appears that pork is more digestible than mutton, this than veal, while beef is the least digestible of any. In feeding dogs with determinate quantities of each, and opening them at the expiration of a given period, it happened that in some instances the pork and mutton had entirely disappeared, while the beef remained but little altered. Fish and cheese were also found to be very digestible substances. Potatoes were digestible in a less degree: 140 HUNTER ON THE ANIMAL CECONOMY. tion than an egg hard boiled, although the raw one must be coagulated in the stomach before it can be digested; and it has likewise been observed, that what is easy of digestion is one stomach will not be so in another; but such cases may probably arise from the stomach not being in a healthy state. In many animals the whole of the food does not appear to be digested, the substance in part being found in the faeces ; for if a dog is fed with tallow, his excrements will consist of a somewhat firm unctuous substance, so that the oil is only digested in part. The circumstance of some part of the food, though digestible, not being acted upon by the gastric juice, may arise from two causes: first, from many parts of vegetables being too firm in texture to be digested in the same time with the other food, and being therefore carried along in a crude state, together with the chyle, into the duodenum; and secondly, from the stomach at the time being so much disordered as to digest imperfectly. We know that food may lie a considerable time in the stomach when it is diseased without being digested. Food has been retained in the stomach twenty-four hours, and thrown up without being in the least altered, the animal at the time not requiring nourishment: this often arises from disease, and is also the case with those which go to rest in the winter. The powers of digestion may in some instances be estimated by the appearance of the excrement, in which, if the food appears not to be much altered, we may conclude that digestion has had little or no influence on it. Thus, the excrement of a flea, that has lived on blood, is nearly, to appearance, pure blood, not having even lost its colour. Animals take food in proportion to the quantity of nourishment contained in it, of which the stomach appears, from instinct, to be capable of judging; and also in proportion to the powers they possess of converting what they eat into chyle. A caterpillar, perhaps, eats more in proportion to its size than any other animal that lives on the same kind of food ; for not having the power of dissolving the vegetable, but only of extracting a juice or infusion from it, the bit of leaf comes away entire, coiled up and hardened ; but, by being put into water, unfolds like tea. There are few animals that do not eat flesh in some form or other, while there are many who do not eat vegetables at ali; and therefore the difficulty to make the herbivorous eat meat is not so great as to make the carnivorous eat vegetables. Where there is an instinctive principle in an animal, directing it either to the one species of food or the other, the animal will certaintly die rather than break through of its own accord that natural law ; but it may be made to violate every natural principle bv artificial means. That the hawk tribe can be made to feed upon bread, I have known these thirty years; for to a tame kite I first gave fat, which it ate very readily; then tallow and butter; and afterwards small balls of Boiled veal was found to be two-thirds more digested than the same meat roasted, &c. Muscular tissue, skin, gristle, tendons, bone, were digestible in the order here set down.] OBSERVATIONS ON DIGESTION. 141 bread rolled in fat or butter, and by decreasing the fat gradually, it at last ate bread alone, and seemed to thrive as well as when fed with meat. This, however, produced a difference in the consistence of the excrements, for when it ate meat they were thin, and it had the power of throwing them to some distance ; but when it ate bread they became firmer in texture, and dropped like excrement of a common fowl. Spallanzani attempted, in vain, to make an eagle eat bread by itself; but by inclosing the bread in meat, so as to deceive the eagle, the bread was swallowed, and digested in the stomach. The excrements of animals we may suppose to be that part of the common food which is indigestible ; and as food is either animal or vegetable, and each different kind adapted to distinct classes of animals, it is natural to believe that the excrementitious part of each will be different; and where the animal feeds upon both, that the excrement will be of a mixed nature. Although this appears probable, it is only true in a certain degree ; for the mode of digestion, and whether the animal has a csecum and colon, with their peculiar form, have all an influence in the changes which the food undergoes. Vegetable food produces more excrement than animal, and this according to the kind or parts of vegetables that are eaten. The woody parts and husks, which are indigestible, produce the most; the true farinaceous part the least: why there should be any at all from the farinaceous and animal substance, except what has eluded the action of the digestive organs, is not easily accounted for. All fasces have a tendency to putrefaction, but least in those animals which feed on vegetables. Indeed, the excrement from vegetable food alone could hardly ever become putrid if it was not mixed with the mucus of the intestines, and would even then be kept sweet by the tendency which undigested vegetables have to take on the vinous and acetous fermentation. But the fseces of those which live entirely on animal food in general very soon become putrid; and indeed often before they are voided ; but such animals are either without caecum or colon; or if not, what they have is very short; so that the excrement not being long retained, has less time to become putrid. When the faeces stagnate so as to take on either the vinous or putrefactive fermentation, air is let loose, which will be according to the nature of the fermentation ; most probably, from the vegetable it will be fixed, and from the animal, inflammable air. The faeces of the greatest number of animals are tinged by the bile, which in some gives them a yellowish-green colour; in the bird they are generally green, but sometimes white, from being mixed with the urine. The fseces of the maggot appear to be loaded with bile; for besides being yellow, they are extremely bitter, which is known by eating the kernel of a nut that has a maggot in it. Some kinds of food, when not wholly digested, give a tinge to the fasces, as grass to the excrement of cows. 142 HUNTER ON THE ANIMAL CECONOMY. The animals which feed upon vegetables alone commonly have their fasces somewhat solid; but the degree will vary according to the state of the vegetable, whether green or dried ; and therefore the particular state of the faeces will depend on the nature of the indigestible part of the food, and must be different according to the digestive powers in different animals. An animal that feeds upon grass has the faeces much softer than when fed on the same kind of grass made into hay; and therefore the faeces of the herbivorous animals are softer in the summer than the winter; but green vegetable food does not produce soft faeces in all animals, for the caterpillar, which lives upon the leaves of vegetables, has its fasces almost dry; and we find in some ruminating animals, as sheep, that the difference in the fseces during summer and winter is inconsiderable. The quadrupeds and birds that live principally upon vegetables generally have their cseca large and the colon long, as we see in many of the ruminating animals. Some have the colon both long and large, as the horse and those of the rat tribe, which circumstance has considerable effects in allowing the faeces to become dry: in a few of the ruminating animals, and of the rat kind, they are formed into small portions. The faeces of quadrupeds living upon animal food are commonly soft, and in birds are fluid ; but in such as live on both animals and vegetables, they are in consistence of a mixed nature, and will be more or less soft according to the food. If a dog is fed entirely on animal substance its fasces will be soft; if wholly on vegetable as on bread, they will become so hard as to be expelled with difficulty.* * [The following differences were found by Dr. Prout in the contents of the rectum of dogs which had been fed*on Vegetable Food. Animal Food. Of a firm consistence, and of an olive Consisted of firm scybala, of a dark browncoIour,incliningtoyellow. Smell brown colour, inclining to chocolate. foetid and offensive. Did not coagulate Smell very foetid. Milk was coagulated milk. by the water in which it had been diffused. A. Water; quantity not ascertained. A. Water; quantity not ascertained. B. Combination or mixture of altered B. Combination or mixture of altered alimentary substances in much greater alimentary matters in much greater exexcess than in the colon, with some cess than in either the colon or caecum, mucus; insoluble in acetic acid, and with some mucus; insoluble in acetic constituting the chief bulk of the fseces. acid, and constituting the chief bulk of the faeces. C. Albuminous matter, none. C. Albuminous matter, none. D. Biliary principle, partly changed D. Biliary principle more considerto a perfect resin. able than in the vegetable faeces, and almost entirely changed to a perfectly resinous-like substance. E. Vegetable gluten? none; but con- E. Vegetable gluten? nonejbutcontained a principle soluble in acetic acid, tained a principle soluble in acetic acid, and precipitable very copiously by oxa- and precipitable very copiously in oxalate of ammonia, late of ammonia. F. Insoluble residuum, consisting F. Insoluble residuum, consisting chiefly of vegetable fibres mixed with chiefly of hairs.] haiis. OBSERVATIONS ON DIGESTION. 143 Spallanzani made some experiments to prove that digestion is carried on after death; but they are not so conducted as to correspond with the appearances met with in the dead body where that process has taken place, and the coats of the stomach itself have been in part digested. An experiment, although it may be very well and accurately made so far as the experiment goes, if a close connexion is not preserved with the purpose for which it was made, the conclusions to be drawn from it cannot correspond with the intention. This is exactly the case with the experiments of Spallanzani, which, although they prove that meat was digested in the stomach after the animal was killed (which no one doubted), yet are not at all calculated to show that the stomach itself may be digested. In fact, the mode in which they were managed rather tended to prevent that effect from taking place, for the gastric juice, by having substances introduced on which it could act, was less likely to affect the coats of the stomach. That the digestion was not carried on merely by the gastric juice secreted before the animal was apparently dead, is evident, from his own account, some of the food which had been introduced and digested being found in the duodenum, a thing that could not have happened if a cessation of the actions of life in the involuntary parts had taken place when visible life terminated. There had been an action, and most probably a secretion, in the stomach. The only experiment that can be made with any probability of a decided result, is to kill the animal while the stomach is empty, and observe what afterwards takes place. There are few stomachs that do not show, when examined after death, some of the inner villous coat destroyed, which may have been done by the gastric juice in the ducts of the glands which secrete it. Dr. Stevens in an inaugural dissertation on this subject, published at Edinburgh 1777, gives a number of experiments, some of which are well devised, to ascertain the substances that are easiest of digestion, a thing in fact more wanted than the cause of that process: but many of his experiments, more especially those on ruminating animals, were not made with sufficient accuracy. How the chopped hay and potherbs came to be so much changed in the first stomach of a ruminating animal I cannot conceive, as 1 have reason to believe it has not the least power of digesting, and should doubt very much that hay was capable of being wholly digested in any stomach. His experiment made on substances out of the body proves that the gastric juice is not able in all cases to prevent the vinous and acetous fermentation in vegetables, and is a circumstance which I believe often takes place in the living body when the stomach is weak. He seems to be in some apprehension for the safety of the stomach itself, from the action of so powerful a solvent as the gastric juice; but though inclined to suppose that the living powers of the animal may guard it against such effects, yet he is still disposed to fear that in all cases they may not be sufficient. The living power in the stomach must indeed be very weak to 144 HUNTER ON THE ANIMAL CECONOMY. admit of its being digested ; where that was likely to happen, I imagine the secretion of the gastric juice would be too defective to allow of the stomach being acted upon. Dr. Stevens gives two cases, with the dissections, to prove that the living stomach has not always the power to resist the action of the gastric juice; but he has not made it clear that those very stomachs might not have been digested after death. The appearance of the edges of the hole should have been more particularly described; for if it took place before death it is probable it was owing to ulceration, which I have sometimes seen. Men should be very accurate in ascertaining the truth of facts before they advance them, especially when they tend either to overturn a received opinion or to establish a new one. As to the possibility of animals swallowed alive being digested, no fresh proofs are necessary, as we eat oysters everyday; but this does not prove that they are digested while alive. In his experiments made on ruminating animals and the dog, as the vegetables were not so readily digested as the meat, he concludes, " It is possible every species of animal has its peculiar gastric liquor, capable of dissolving certain substances only" which is certainly not true. Mr. Senebier relates some experiments made by Mr. Gosse upon himself, but which hardly contain anything except a curious conjecture of Mr. Senebier's, " That distention of the stomach is the cause of the secretion of the gastric liquor." He mentions the substances, both animal and vegetable, which are not digestible: then those difficult of digestion : afterwards, those easily digested; also what substances facilitate digestion, and what retard it. But if we are to judge of the truth of these facts from a detail of the experiments which he made to ascertain them, I am quite inclined to believe that the experiments have not been made with sufficient accuracy to be depended upon. 11. ON THE DIGESTION OF THE STOMACH AFTER DEATH.

The following account of the stomach being digested after death was drawn up at the desire of the late Sir JohnPringle, when he was President of the Royal Society; and the circumstance which led to it was as follows. I had opened, in his presence, the body of a patient who had been under his care, in which the stomach was found to be in part dissolved ; a thing that appeared to him very accountable, there having been no previous symptom which could have led him to suspect any disease in the stomach. I took that opportunity of explaining to him my ideas respecting it; and that, having long been employed in making experiments on digestion, I had been induced to consider this as one of the facts which proved a converting power in the gastric juice. I mentioned my intention DIGESTION OF THE STOMACH AFTER DEATH. 145

of publishing the whole of my observations on digestion at some future period; but he desired me, in the meantime, to give this fact by itself, with my remarks ; as it would prove that there is a solvent power existing in the stomach, and would be of use in the examination of dead bodies.* An accurate knowledge of the appearances in animal bodies, where death has been the consequence of some violence while they were otherwise in health, ought certainly to be considered as necessary to qualify us to judge truly of the state of the body in those that die of diseases. An animal body undergoes changes after death; but it has never been sufficiently considered what those changes are, or how soon they may take place; yet till this be done it is impossible we can form an accurate judgment of the appearances which present themselves at the time of inspection. The diseases of an animal body (mortification excepted) are always connected with the living principle, and are not in the least similar to the changes which take place in the dead body: without a knowledge of this, an opinion drawn from dissections must always be very imperfect or very erroneous. Appearances which are in themselves natural may be mistaken for those of disease ; we may see diseased parts, and suppose them in a natural state; we may consider a circumstance to have existed before death which was really a consequence of it; or we may imagine it to be a natural change after death, when it was in fact a disease of the living body. It is easy to see, therefore, how a man in this state of ignorance must blunder when he comes to connect the appearances in a dead body with the symptoms that were observed in life; and, indeed, all the advantage to be derived from opening dead bodies depends upon the judgment and sagacity with which this sort of comparison is made. • There is a case of a mixed nature, which can neither be reckoned a process of the living body nor of the dead : it participates of both, inasmuch as its cause arises from life, and the effect cannot take place till after death. To render this more intelligible, it will be necessary to state some general ideas concerning this cause and effect. An animal substance, when joined with the living principle, cannot undergo any change in its properties but as an animal; this principle always acting and preserving the substance possessed of it from dissolution, and from being changed according to the natural changes which other substances undergo. * TThe original paDer is printed in the 62d volume of the Philosophical Transactions; and was read June 18th, 1772. It begins as follows: "An accurate knowledge of the appearances in animal bodies that die of a violent death, that is in'perfect health, or in a sound state, ought to be considered as a necessary foundation for judging of the state of the body in those that are diseased." The remainder of the essay is given in the 2d edition of the Animal CEconomy, with verbal alterations of the same kind and degree as are exemplified in the paragraph qbove quoted ; with the omission of one sentence and a note, which are' subjoined at the end of the paper.] 14 146 HUNTER ON THE ANIMAL CECONOMY. There are a great many powers in nature which the living principle does not enable the animal matter, with which it is combined, to resist, viz., the mechanical and most of the strongest chemical solvents. It renders it, however, capable of resisting the powers of fermentation, digestion, (and perhaps several others,) which are well known to act on this same matter, and entirely to decompose it, when deprived of the living principle. The number of powers which thus act differently on the living and dead animal substance not being ascertained, we shall only take notice of two, putrefaction and digestion, which do not affect this substance, unless when it is deprived of the living principle. Putrefaction is an effect which arises spontaneously; digestion is an effect of another principle,, and shall here be considered a little more particularly. Animals, or parts of animals, possessed of the living principle, when taken into the stomach, are not in the least affected by the powers of that viscus so long as the animal principle remains. Hence it is that we find animals of various kinds not only can live in the stomach, but are even hatched and bred there; yet the moment that any of these lose the living principle, they become subject to the digestive powers of the stomach. If it were possible for a man's hand, for example, to be introduced into the stomach of a living animal, and kept there for some considerable time, it would be found that the dissolvent powers of the stomach could have no effect upon it; but if the same hand were separated from the body, and introduced into the same stomach, we should then find that the stomach could immediately act upon it. Indeed, if the first were not the case, the stomach itself ought to have been made of indigestible materials; for were not the living principle capable of preserving animal substances from being acted upon by the process of digestion, the stomach itself would be digested ; and accordingly we find that the stomach, which at one instant, that is, while possessed of the living principle, was capable of resisting the digestive powers which it contained, the next moment, viz., when deprived of the living principle, is itself capable of being digested, not only by the digestive powers of other stomachs, but even by the remains of that power which itself had of digesting other things. These observations lead us to account for an appearance which we often find in the stomachs of dead bodies ; and they at the same time throw considerable light upon the nature of digestion. The appearance we allude to is a dissolution of the stomach at its great extremity, in consequence of which there is frequently a considerable aperture made in that viscus. The edges of this opening appear to be half dissolved, very much like that kind of solution which fleshy parts undergo when half digested in a living stomacb, or when acted upon by a caustic alkali, viz., pulpy, tender and ragged. In these cases the contents of the stomach are generally found loose in the cavity of the abdomen, about the spleen and diaphragm; and in many subjects the influence of this digestive power extends DIGESTION OF THE STOMACH AFTER DEATH. M7

much further than through the stomach. I have often found that, after the stomach had been dissolved at the usual place, its contents let loose had come into contact with the spleen and diaphragm, had dissolved the diaphragm quite through, and had partly affected the adjacent side of the spleen, so that what had been contained in the stomach was found in the cavity of the thorax, and had even affected the lungs to a small degree. There are very few dead bodies in wmich the stomach at its great end is not in some degree digested; and one who is acquainted with dissections can easily trace these gradations. To be sensible of this effect nothing more is necessary than to compare the inner surface of the great end of the stomach with any other part of its inner surface: the sound portions will appear soft, spongy, and granulated, and without distinct blood-vessels, opake and thick; while the others will appear smooth, thin, and more transparent; and the vessels will be seen ramifying in its substance, and upon squeezing the blood which they contain from the larger branches to the smaller, it will be found to pass out at the digested ends of the vessels, and to appear like drops on the inner surface. Though I have often seen such appearances, and supposed that they must have been seen by others, yet I was quite at a loss to account for them. At first I supposed them to have been produced during life, and was therefore inclined to look upon them as the cause of death, only that I never found they had any connexion with the patient's symptoms; but I was still more at a loss to account for them when I discovered they were most frequent in those who died by sudden violence; a circumstance which made me suspect that the true cause was not guessed at.* At this time I was employed in making experiments upon digestion in different animals, all of which were killed at different times, after having been fed with various kinds of food : many of these were not opened immediately after death, and in some of them I found the above-described appearances in the stomach. The better to pursue my inquiry on the subject of digestion, I procured the stomachs of a vast variety of fishes, whose deaths are always violent, and who may be said to die in perfect health, with their stomachs usually

* The first time that I had occasion to observe this appearance where death had been produced by violence, and where it could not therefore easily be supposed to be the effect of disease, was in a man who had his skull fractured by one blow of a poker. Just before this accident he had been in perfect health, and had taken a hearty supper of cold meat, cheese, bread, and ale. Upon opening the abdomen, I found that the stomach, though it still contained a good deal, was dissolved at its great end, and a considerable part of its contents lay loose in the general cavity of the belly ; a circumstance which puzzled me very much. The second instance was in a man who died at St. George's Hospital, a few hours after receiving a blow on his head which fractured his skull. From these two cases, among various conjectures about so strange an appearance, I began to suspect it mio-ht be peculiar to cases of fractured skull, and therefore, whenever I had an opportunity, I examined the stomach of every person who died from that accident; but 1 found many of them which had not this appearance. I afterwards met with the same appearance in a man who had been hanged. 148 HUNTER ON THE ANIMAL CECONOMY. full. In them we can observe the progress of digestion most distinctly, the shape of their stomachs being very favourable for that purpose. They likewise swallow their food whole, that is, without mastication, and swallow fish that are much larger than the digesting part of the stomach can contain; therefore in many instances the part swallowed which was lodged in the digesting part of the stomach was found more or less dissolved, while that which remained in the oesophagus was perfectly sound ; and in many of these I saw the digesting part of the stomach itself reduced to the same dissolved state as the digested part of the food. Being employed upon this subject, and therefore enabled to account more readily for appearances which had any connexion with it, and observing that the half-dissolved parts of the stomach were similar to the half-digested food, it immediately struck me that it was the process of digestion going on after death ; and that the stomach, being dead, was no longer capable of resisting the powers of that menstruum which itself had formed for the digestion of food.* These appearances of the stomach after death throw considerable light on the principles of digestion, and show that it neither depends on a mechanical power, nor contractions of the stomach, nor on heat, but something secreted in the coats of the stomach, and thrown into its cavity, which there animalizes the food, or assimilates it to the nature of the blood.f The power of the gastric juice is confined or limited to certain substances, generally of the vegetable and animal kingdoms ; and although this menstruum is capable of acting independently of the stomach, yet it is indebted to that viscus for its existence and continuance.

* [Then follows in the original paper: " With this idea, I set about making experiments to produce these appearances at pleasure, which would have taught us how long the animal ought to live after feeding, and how long it should remain after death before it is opened; and above all, to find out the method of producing the greatest digestive power in the living stomach: but this pursuit led me into an unbounded field."—Phil. Trans. (1772), p. 453.] | [In the original paper the following note here occurs: " In all the animals, whether carnivorous.or not, upon which I made observations or experiments to discoyer whether or not there was an acid in the stomach (and I tried this in a great variety), I constantly found that there was an acid, but not a strontr one, in the juices contained in that viscus in a natural state." The omission" of this note both in the 1st and 2d editions of the Animal CEconomy was probably a consequence of the doubt subsequently entertained by Hunler of the natural presence of an acid in the gastric juice; but as the existence of hydrochloric acid as an essential constituent of the animalizing secretion of the stomach is now satisfactorily determined, we have thought it proper to restore this record of the agreement of a great proportion of Hunter's experience with that of late observers on this subject.] SECRETION IN THE CROP OF BREEDING PIGEONS. 149 12. ON A SECRETION IN THE CROP OF BREEDING PIGEONS, FOR THE NOURISHMENT OF THEIR YOUNG.

The nourishment of animals admits, perhaps, of as much variety in the mode-by which it is to be performed as any circumstance connected with their ceconomy, whether we consider their numerous tribes, the different stages through which every animal passes, or the food adapted to the support of each in their distinct conditions and situations. We are likewise to include in this view that endless variety in the means by which this food is procured, according to the class of the animal and the particular stage of its existence. If the food was the same through every period of the life of an animal; if every individual of a tribe lived on the same kind, and procured it by the same mode, our speculations would then admit of a regular arrangement. But when we see that the food adapted to one stage of an animal's life is rejected at another, and that animals of one class in some respects resemble those of another, by hardly having any food peculiar to themselves, the subject becomes so complicated that it is not surprising if we are at a loss to arrange' the various modes by which animals are nourished. Animal life may not improperly be divided into three states or stages. The first comprehends the production of the animal and its growth in the fcetal state; the second commences when it emerges from that state by what is called the birth, yet for a certain time must, either mediately or immediately, depend on the parent for support; the third may be said to take place when the animal is fit and at liberty to act*for itself. The first and third stages are perhaps common to all animals; but there are some classes, as fishes, spiders, &c, which seem to have no second stage, but pass directly from the first to what is the third in. other animals. Of those requiring a second stage, the polypus and the viviparous animals continue to derive their nourishment immediately from the parent: while the oviparous are for some time supported by a substance originally formed with them, and reserved for that purpose.* There is infinite variety in the means by which Nature provides

* [The species of polypus to which Mr. Hunter here refers is most probably the freshwater gemmiparous hydra; but the period during which the young polype is growing at the expense of the parent seems rather to correspond to the first or fcetal stage of existence than the second : when, again, the communication with the digestive sac of the parent is obliterated, the young polype derives its nourishment from without by the exercise of its tentacles, until it is finally cast off. The viviparous animals are the Mammalia, and the nourishment alluded to is the lacteal secretion. The nutritious substance with which the oviparous animals continue for a short period to be supported after their exclusion from the egg is the yolk, which has then passed into the abdomen, where it is finally absorbed.] 14* 150 HUNTER ON THE ANIMAL CECONOMY. for the support of the young in the second stage of animal life. In many insects it is effected by the female instinctively depositing the egg, or whatever contains the rudiments of the animal, in such a situation that, when hatched, it may be within reach of proper food; others, as thcjhumble-bee and black-beetle ' [Blatta],' collect a quantity of peculiar substance, which both serves as a nidus for the egg, and nourishment for the maggot, when the embryo arrives at that state. Most birds, and many of the bee-tribe, collect food for their young; when at a more advanced period the task of feeding them is performed by both male and female, with an exception in the common bee, the young ones of which are not fed by either parent, but by the working-bees, which act the part of the nurse. There is likewise a number of animals capable of supplying immediately from their own bodies the nourishment proper for their offspring during this second stage, a mode of nourishment which has hitherto been supposed to be peculiar to that class of animals which Linnaeus calls Mammalia; nor has it, I imagine, been ever suspected to belong to any other. 1 have, however, in my inquiries concerning the various modes in which young animals are nourished, discovered that all of the dove kind are endowed with a similar power. The young pigeon, like the young quadruped, till it is capable of digesting the common food of its kind, is fed with a substance secreted for that.purpose by the parent animal; not, as in the Mammalia, by the female alone, but also by the male, which, perhaps, furnishes this nutriment in a degree still more abundant. It is a common property of birds, that both male and female are equally employed in hatching, and in feeding their young in the second stage; but this particular mode of nourishment, by means of a substance secreted in their own bodies, is peculiar to certain kinds, and is carried on in the crop. Besides the dove kind, I have some reason to suppose parrots to be endowed with the same faculty, as they have the power of throwing up the contents of the crop, and feeding one another. I have seen the cock parroquet regularly feed the hen, by first filling his own crop, and then supplying her from his beak. Parrots, maccaws, cockatoos, &c, when they are very fond of the person who feeds them, may likewise be observed to have the action of throwing up the food, and often do it. The cock pigeon, when he caresses the hen, performs the same kind of action as when he feeds his young; but I do not known if at this time he throws up anything from the crop. During incubation the coats of the crop in the pigeon are gradually enlarged and thickened, like what happens to the udder of females of the class Mammalia in the term of uterine gestation. On comparing the state of the crop when the bird is not sitting, with its appearance during incubation, the difference is very remarkable. In the first case it is thin and membranous; but by the time the young are about to be hatched, the whole, except what lies on the ON THE GILLAROO-TROUT. 151 trachea, becomes thicker, and takes on a glandular appearance, having its internal surface very irregular. It is likewise evidently more vascular than in its former state, that it may convey a quantity of blood sufficient for the secretion of the substance which is to nourish the young brood for some days after they are hatched. Whatever may be the consistence of this substance when just secreted, it most probably very soon coagulates into a granulated white curd, for in such form I have always found it in the crop ; and if an old pigeon is killed just as the young ones are hatching, the crop will be found as above described, and in its cavity pieces of white curd, mixed with some of the common food of the pigeon, such as barley, beans, &c. If we allow either of the parents to feed the brood, the crop of the young pigeons when examined will be discovered to contain the same kind of curdled substance as that of the old ones, which passes from thence into the stomach, where it is to be digested. The young pigeon is fed for a little time with this substance only, as about the third day some of the common food is found mingled with it: as the pigeon grows older the proportion of common food is increased ; so that by the time it is seven, eight, or nine days old, the secretion of the curd ceases in the old ones, and of course no more will be found in the crop of the young. It is a curious fact that the parent pigeon has at first a power to throw up this curd without any mixture of common food, although afterwards both are thrown up according to the proportion required for the young ones. I have called this substance curd, not as being literally so, but as resembling that more than anything I know; it may, however, have a greater resemblance to curd than we are perhaps aware of, for neither this secretion, nor curd from which the whey has been pressed, seems to contain any sugar, and do not run into the acetous fermentation. The property of coagulating is confined to the substance itself, as it produces no such effect when mixed with milk. This secretion in the pigeon, like all other animal substances, becomes putrid by standing, though not so readily as either blood or meat, it resisting putrefaction for a considerable time; neither will curd much pressed become putrid so soon as either blood or meat. 13. OBSERVATIONS ON THE GILLAROO-TROUT, COM- MONLY CALLED IN IRELAND THE GIZZARD- TROUT.*

One of the digestive organs of the gillaroo-trout being so very remarkable as to have given name to the fish, and to have been considered as its distinguishing characteristic, it is my intention to * [Originally published in the Philosophical Transactions, vol. lxiv. (1774.)] 152 HUNTER ON THE ANIMAL CECONOMY. inquire whether its resemblance to a gizzard be sufficiently strong to render the term of gizzard-trout a proper appellation, and what place its stomach ought to hold among the corresponding organs of other animals. For this purpose it will be necessary to state certain facts connected with the subject, and take a general view of the varieties which occur in the digestive organs in different animals. The food of animals may be divided into two kinds, what does, and what does not, require mastication to facilitate digestion. The flesh of animals is of the latter kind; but grain, and many other substances which serve for aliment, require a previous grinding or trituration, and therefore animals living on this kind of food are furnished with organs for that purpose. Granivorous quadrupeds have the two powers, for mastication and digestion, separate or distinct from one another; the first being executed by teeth, which serve as so many grindstones for reducing their food to smaller parts, before it is conveyed into the stomach for digestion; but the form of these teeth varies very considerably in different animals, although the food be the same. This grinding also fits it for deglutition ; for neither grain nor herbs could be swallowed without having first been masticated. When so prepared, it is, with regard to the digestive power, rendered similar to animal food; therefore in many of the granivorous the stomach resembles that of the carnivorous animals ; and whenever the stomach in the granivorous quadruped departs from this general rule, there is a peculiarity in the operations of digestion. Birds that live upon substances, for the digestion of which trituration is indispensably necessary, have the powers of mastication and digestion united in one part, the gizzard, which is particularly constructed for that purpose, but is more uniform in its construction than the teeth, varying only by being stronger or weaker in its powers; therefore the genius of birds exhibits less variety, respecting the organs relating to digestion, than the quadruped. In granivorous birds, therefore, one single organ answers both to the teeth and stomach of granivorous quadrupeds, and consequently the gizzard alone of birds will as clearly point out the food ofthe species as both teeth and stomach together, in those animals in which the two offices of mastication and digestion are not performed together in the same part. As it appears to be the difference of stomachs only that fits birds for their different kinds of food, as there is little difference in construction, excepting only in strength ; and as the food of the different species is of every kind, from the hardest grain to the softest animal matter, we may conclude that every gradation ofthe stomach is to be found among them, from the true gizzard, which is one extreme, to the mere membranous stomach, which is the other. In consequence of this, it must be as difficult to determine the exact limits of the two different modes of construction to which the names of gizzard and stomach specifically belong, as, in any other case, to distinguish proximate steps in the slow and imperceptible gradations of Nature. ON THE GILLAROO-TROUT. 153 The two extremes of true gizzard and membranous stomach are easily defined; but they run so into each other, that the end of one and the beginning of the other is quite imperceptible. Similar gradations are observable in the food: the kinds suited to the two extremes mixing together in different proportions adapted to the intermediate states of stomach. A true gizzard is composed of two strong muscles, placed opposite and acting upon each other, like two broad grindstones. These muscles are joined together at their sides by a middle tendon, into which the muscular fibres are inserted, and which forms the narrow anterior and posterior sides of the flat quadrangular cavity in which the grinding is performed. The upper end of this cavity is occupied by the termination of the oesophagus, and the beginning of the intestine. The lower end consists of a thin muscular bag connecting the edges ofthe two muscles together. By these two more soft and flexible substances being thus interposed between the two strong grinding muscles a double advantage is gained; for whilst one gives an easy passage to the oesophagus and gut, when both act together they serve in some degree as a hinge, on which the two muscles may be said to move, by the middle tendon, allowing of a free motion of the grinding surfaces on each other, which is necessary for the comminution of food. The two flat lateral sides of the grinding cavity are lined with a thick horny substance, similar to a hard and thick cuticle; the narrow anterior and posterior tendinous parts are also lined with a cuticle, but not so strong as the former; this horny substance is gradually lost at one end in a very thin cuticle, which lines the passages ofthe oesophagus and intestine for a little way, and at the other end is lost in the same manner in the membranous bag. The two large muscles may be considered as a pair of jaws, whose teeth are occasionally supplied, being small rough stones or pebbles which the animal swallows, which from the feeling of the tongue can distinguish such as are proper from those which are not, instantly dropping out of its mouth such as are smooth and otherwise unfit for the purpose. Some birds with gizzards have also a craw or crop, which serves as a reservoir, and for softening the grain ; but as all of them have not this organ it is not to our present purpose. There are other animals, besides this class of birds, which masticate their food in the stomach; but teeth are placed there by Nature ; of this kind are crabs and lobsters. The gradation from gizzard to stomach is made by the muscular sides becoming weaker and weaker, and the food keeps pace with this change, varying gradually from vegetable to animal.* In one point of view, therefore, food may be considered as a first principle, with respect to which the digestive organs with their appendages

* [The trizzards of birds which live on hard-coated coleopterous insects are stronger than those which have to digest soft pulpy fruits.] 154 HUNTER ON THE ANIMAL CECONOMY. act as but secondary parts, being adapted to and determined by the food as the primary object. We find then that in all granivorous animals there is an apparatus for the mastication of the food, although often differing in construction and situation ; but in true carnivorous animals, of whatever tribe, mastication not being so necessary, they have no apparatus for that purpose. The teeth of such quadrupeds as are carnivorous serve chiefly to procure food and prepare it for deglutition; the same thing is performed in the true carnivorous birds by their beak and talons, whose office it is to procure the aliment and fit it for deglutition, corresponding in this respect with the teeth ofthe others. Applying this reasoning to fish, it seems, at first sight, as if there were 'no occasion in them for that variety of structure in the digestive organs as is found in the before-mentioned quadrupeds and birds, the food of fish being principally of one sort, namely animal; which, however, with regard to the digestive powers, is to be distinguished into two kinds, viz., common soft and shell-fish. Such fish as live on the first kind have, like the carnivorous quadrupeds and birds, no apparatus for mastication, their teeth being intended merely for catching the food and fitting it to be swallowed. But the shells of the second kind of food render some degree of masticating power necessary to fit it for its passage either into the stomach or through the intestines ; and accordingly we find in certain fish a structure suited to the purpose. Thus the mouth of the wolf-fish is almost paved with teeth, by means of which it can break shells to pieces and fit them for the oesophagus of the fish, and so effectually disengage the food from them, that though it lives upon such hard food, the stomach does not differ from that of other fish; the organs of mastication and digestion, therefore, in this animal, exactly correspond to those of many granivorous quadrupeds. Other fish, on the contrary, approach nearer to the structure of birds by having their stomach furnished to a certain degree with a masticating power, which in many is very imperfect compared with the gizzards of fowls. Perhaps the difference is only what the difference of food will properly allow ; as in fish which have this power, the food being still animal, and in general but imperfectly covered with the shell, it probably requires only to be broken, perhaps hardly that, for the mere purposes of digestion, as food is digested when introduced into the stomach in silver balls with only a few small holes, but it may be necessary to fit the shells for passing along the intestines after the fish is digested. In the Bulla Kgnaria of Linnseus this apparatus is more perfect, consisting of two bones, which we must suppose capable of grinding hard shells; but the food of granivorous birds requires to be ground into a kind of meal. Of all the fish I have seen, the mullet is the most complete instance of this structure, its strong muscular stomach being evidently adapted, like the gizzard of birds, to the two offices of mastication and digestion. The stomach of the fish now before us holds the second place. ON ANIMALS PRODUCING HEAT. 155 But still neither of these stomachs can be justly ranked as gizzards, since they want some of the most essential characters, viz., a power and motion fitted for grinding, and the horny cuticle.* The stomach of the gillaroo-trout is, however, more globular than that of most fish, better adapted for small food, and endued with sufficient strength to break the shells of small shell-fish; which will probably be best done by having more than one in.the stomach at a time, and also by. taking pretty large and smooth stones into the stomach, which will answer the purpose of breaking, but not so well that of grinding, nor will they hurt the stomach, as they are smooth, when swallowed ; but this stomach can scarcely possess any power of grinding, as the whole cavity is lined with a fine villous coat, the internal surface of which appears everywhere to be digestive, and by no means fitted for mastication. The stomach of the common stream-trout is exactly of the same structure with that of the gillaroo ; but its coat not so thick by two thirds.f How far this difference in thickness of stomach is sufficient to form a distinct species, or barely a variety of the same, is only to be determined by experiment.^ The oesophagus in the trout is considerably longer and smaller than in many other classes of fish. The intesines are similar to those of the salmon, herring, sprat, &c. The pancreas is appendiculated. The teeth show them to be fish of prey. So far as we are led to determine by analogy, we must not consider the stomach of this fish as a gizzard, but as a true stomach. 14. EXPERIMENTS AND OBSERVATIONS ON ANIMALS, WITH RESPECT TO THE POWER OF PRODUCING HEAT.§

Some late ingenious experiments and observations, published in the Philosophical Transactions,|| upon a power which animals seem

* [We have examined the gizzard ofthe mullet (Magil Capito, Cuv.),and find that it is lined by a distinct layer of rough and easily separable cuticle.] f The common stream-trout swallows shell-fish, and also pretty large smooth stones, which serve as a kind of shell-breakers. X Viz., take some gillaroo-trout, male and female, and put them into water in which there are no trout, to see if they continue the same.1 § [This Essay includes the greater part of two papers, one published with the title 'Experiments on Animals and Vegetables, with respect to the Power of producing Heat,' in the Philosophical Transactions, vol. Ixv. (read June 22, 1775); the other, 'On the Heat, &c, of Animals and Vegetables,' in the Philosophical Transactions, vol. lxviii. (read Juno 19, and Nov. 13, 1777.)] || [' Experiments and Observations in a heated Room,' by Charles Blagden, M.D., F.R.S., vol. Ixv., p. 111.] a [They are considered to be varieties of the Salmo Fario, Linn., by the best modern naturalists: see Yarrell's « British Fishe3,' vol. ii., p. 57.] 156 HUNTER ON THE ANIMAL CECONOMY.

to possess of generating cold, induced me to look over my notes, containing some which I had made in the year 176(5, indicating an opposite power in animals, whereby they are capable of resisting any external cold while alive, by generating within themselves a degree of heat sufficient to counteract it. Those experiments were not originally instituted with any expectation of the event which resulted from them, but for the purpose of satisfying myself whether an animal could retain life after being frozen, as has been confidently asserted both of fishes and snakes. For that these, after being frozen, still retain so much of life as when thawed to resume their vital actions, is a fact so well attested that we are bound to believe it; and had my experiment succeeded, it was my intention to have fried the effects of freezing on living animals to a much greater degree than can ever happen accidentally. I mention these circumstances to account for what might otherwise be attributed to negligence and inattention, namely, the little nicety that was observed in measuring the precise degree of cold applied in the experiments. Accuracy in this particular was not aimed at, being of no consequence in the inquiry more immediately before me. The cold was first produced by means of ice and snow with sal ammoniac or sea-salt, to about the 10° of Fahrenheit's thermometer : ice. was then mixed with spirit of nitre; but what degree of cold was thus produced I did not examine. This cold mixture was made in a tub surrounded with woollen cloths, and covered with the same, to prevent the effects of the heat of the atmosphere upon the mixture itself, and to preserve, as much as possible, a cold atmosphere within the vessel. Animal juices, as the blood, freeze at 25°, so that a piece of dead flesh could be frozen in an atmosphere cooled to that point.

Experiment I. was made on two carp. These were put into a glass vessel with common river water, which was placed in the freezing mixture. The water not freezing fast enough, to hasten that effect as much cooled snow was added as to render the whole thick. The snow round the carp melting, we put in more fresh snow, which, melting also, was repeated several times, till we grew tired, and at last left them covered up in the yard to freeze by the joint operation ofthe surrounding mixture and the natural cold" of the atmosphere.* They were frozen at last, after having exhausted the whole powers of life in the production of heat. That this was really the case, could not be known till I had completed that part of the experiment for which the whole was begun, viz., the thawing ofthe

* [This experiment is alluded to by Dr. Blagden, who observes, "The power of generating heat seems to attend life very universally. Not to mention other well-known experiments, Mr. Hunter found a carp preserve a coat of fluid water round him long after all the rest of the water in the vessel had been congealed by a very strong freezing mixture."—Phil. Trans., Ixv., p. 122.] ON ANIMALS PRODUCING HEAT. 157 animals. It was done very gradually; but the animals did not, with flexibility, recover life ; and while in this cold, showed signs of great uneasiness by their violent motions. JV.B. In some of these experiments, where air was made the conductor of the cold and heat, that the heat might be more readily carried offfrom the animal, a leaden vessel was used. It was small for the same reason ; and as it was necessary for the animal's respiration that the mouth of the vessel should communicate with the open air, it was made deep, that the cold ofthe atmosphere round the animal might not be diminished too quickly by the warmth ofthe open air, which would have spoiled it as a conductor. Experiment II. was upon a dormouse, the vessel in which it was confined being sunk in the cold mixture almost to its edge. The atmosphere round the animal soon cooled ; its breath froze as it came from the mouth ; a hoar-frost gathered on its whiskers, and on all the inside of the vessel, and the external points of the hair became covered with the same. While this was going on the animal showed signs of great uneasiness ; sometimes it would coil itself into a round form, to preserve its extremities and confine its heat; and finding that ineffectual, would then endeavour to make its escape.* Its motions became less violent by the sinking ofthe vital powers: its feet were at last frozen: but we were not able to keep up the cold a sufficient time to freeze the whole animal, the hair being so bad a conductor of heat that the consumption was not more than the animal powers were capable of supporting.! Experiment III. was made with another dormouse; and taught by the failure of the last experiment, I took care that the hair should not a second time be an obstruction to our success. Having, therefore, first made the animal wet all over, that its heat might be more rapidly carried off, it was put into a leaden vessel, and the whole placed in the cold mixture as before. The animal soon gave signs of feeling the cold, by repeated attempts to make its escape; and the breath and water evaporating from its body being soon frozen, appeared like a hoar-frost on the sides of the vessel and on its whiskers ; but while the vigour of life lasted it defied the approach of the cold. However, from the hair being wet, and thereby rendered a good conductor, there was a much greater consumption of heat than in the former experiment, which hastened on the diminution ofthe power of producing it. The animal dying, soon became stiff, and, upon being thawed, was found quite dead. Experiment IV. A toad being put into a vessel with water, at such a depth as not to cover its mouth, was placed in the mixture

* This shows that cold carried to a great degree rather rouses than depresses the animal action ; but it appears, from many circumstances and observations, that a certain degree of cold produces inactivity both in living and sensative principle, which will be further illustrated hereafter. f These experiments were made in presence of Dr. George Fordyce and Dr. Erwin, teacher of Chemistry at Glasgow, the latter of whom came in accidentally in the middle of our operations. 25 158 HUNTER ON THE ANIMAL O3C0N0MY. cooled to between 10° and 15°. The water froze so near to the body of the animal as quite to inclose it, but without destroying life; yet, though not frozen, it hardly ever recovered the use of its limbs. Experiment V. was with a snail, which froze very soon, in a.cold between 10° and 13°. These two last experiments were made in the winter, when the living powers of the animals selected for the trial are very weak; they might have resisted the cold more strongly in the summer. Why the animals mentioned in the above experiments died before they were frozen, while those which are exposed to the atmosphere in very cold climates do not, is a point I shall not pretend to determine, not knowing the difference between the effects of a natural and an artificial cold. It may be accounted for by supposing that the natural cold in climates in which animals are found frozen is so intense as to produce congelation immediately, before the powers of life are exhausted; at least whether it is so or not is worthy of inquiry. It appears from the above experiments, first, That most probably the animals were deprived of life before they were frozen; secondly, That there was an exertion or expense of animal power in resisting the effects of oold, proportioned to the necessity; thirdly, That this exertion was in proportion to the perfection ofthe animal and the natural heat proper to each species and to each age. This exertion might also perhaps depend in some degree on other circumstances not hitherto observed ; for from Experiments II. and III. upon dormice, I find that in the animals which are of a constitution to retain nearly the same heat in all temperatures of the air, it required the greatest cold I could produce to overcome this resisting power; while by Experiments IV. and V. on the toad and snail, whose natural heat is not always the same, but is altered very materially according to the external heat or cold, this power was exhausted in a degree of cold not exceeding 10° or 15°; and the snail being the most imperfect of the two, its powers of generating heat appeared to be much the weakest. That the imperfect animals will allow of a considerable variation in the temperature of heat and cold, is proved by the following experiments. The thermometer being at 45°, the ball was introduced by the mouth into the stomach of a frog, which had been exposed to the same cold. It rose to 49°. I then placed the frog in an atmosphere made warm by heated water, where I allowed it to stay twenty minutes; and upon introducing the thermometer into the stomach, it raised the quicksilver to 64°. To what degree the more imperfect animals are capable of being rendered hotter and colder at one time than another, I have not yet ascertained;*

Abano iperature • ii a certain degree torpid in cold water, but revive and exhibit lively motions when placed in warm water of 95° Fahrenheit.] r ON ANIMALS PRODUCING HEAT. 159 but the forpidity of these animals in our winter is. probably owing to the great change wrought in their temperature by the external heat and cold. The cold in their bodies is to such a degree as in a great measure to put a stop, while it lasts, to the vital functions; while in warmer climates no such effect is produced.* This variety (in the power of producing heat) not only takes place in animals of different orders, but in some degree in the same animal at different ages, even according to the different age of the parts in the same animal: a young animal requires more warmth than one full-grown ; and although an animal is equally old in all its original parts, yet, there are often new ones formed in consequence of disease; and we find that these new or young parts in animals are not so able to support life as the old, at least for some time : but as animals are of different ages, and the same animal is always growing older, and of course more and more perfect, the)' then become more capable of generating heat than when they were younger.f This, however, has its limitations, for after a certain period they again lose this power, and therefore require a less strongly conducting medium, or warm atmosphere. This power of generating heat seems to be a property in an animal while alive. In the more perfect animals it is to preserve a standard heat; and as they are most commonly in an atmosphere colder than themselves, they have most commonly occasion to exert it, and it is therefore a power only of opposition and resistance; for it is not found to exert itself spontaneously and unprovoked, but must always be excited by the energy of some external frigorific agent, or disease: yet it is natural to such animals that this power should be called forth, as will be observed by and by. It does not depend on the motion of the blood, as some have supposed, because it likewise belongs to animals which have no circulation :J and the nose of a dog, which is always nearly of the same

* [The Reptiles and many ofthe Invertebrate animals of tropical climates seek their hiding-places and fall into a slate of lethargy during the dry season, when the heat is most intense. A quadruped of Madagascar, the tenrec, which is nearly allied to our hedgehog, becomes lethargic at the dry season, when its insect food is inaccessible.] f [Young animals consume, in proportion, less oxygen than adults; consequently, a less proportion of carbonic acid is formed in the change ofthe arterial into the venous blood, and a less amount of heat is extricated. When exposed to cold they become torpid, lose their heat, and also their sensibility, in which latter circumstance, and in some other points, they differ considerably from the hybernaling animal in its state of lethargy.] X [An argument of this importance deserved to be stated with more circumstance. Mr. Hunter does not say what the animals are which have no circulation. It is possible, however, that he was alluding to bees. But these insects we know enjoy a circulation, governed, as his own dissections show, by a dorsal heart. And insects manifest the power of generating heat above that of other invertebrate animals precisely in consequence ofthe greater activity of their locomotive, respiratory, and sanguiferous functions. It is true, however, that mere motion ofthe blood is not a cause of animal heat, because the circulation goes on in the hybernating animal when in its cold and lethargic state ; but the blood's motion is here inoperative as a cause of heat, because in torpidity no chemical 160 HUNTER ON THE ANIMAL CECONOMY. heat in all temperatures of the air, is well supplied with blood ;* although we must allow, where this power is greatest the circulation is the quickest. Neither can it be said to depend upon the nervous system, for it is found in animals that have no brain or nerves. However, it must be allowed that all that class which possess this power in the highest degree have the largest brain, although this power is not in the least in proportion to the quantity of brain in that class.f It is most probable that it arises from some other principle;-a principle so connected with life that it can, and does, act independently of circulation, sensation, and volition, and is that power which preserves and regulates the internal machine. This power of generating heat is in the highest perfection when the body is in health; and in many deviations from that state we find that its action is extremely uncertain and irregular, sometimes rising higher than the standard, and at other times falling much below it. Instances of this we have in different diseases, and even in the same disease, within very short intervals of time. A very remarkable one fell under my own observation, in a gentleman who was seized with an apoplectic fit; and while he lay insensible in bed, covered with blankets, I found that his whole body would, in an instant, become extremely cold in every part, continuing so for some time ; and, as suddenly, would become extremely hot. While this was going on alternately there was no sensible alteration in his pulse for several hours. J Being satisfied of the foregoing fact, that animals had a power of generating heat, I pursued the subject still further; not so much with a view to account for animal heat, as to observe the different phenomena, with the variations or difference in the heat in different

change takes place in the blood during its passage through the capillaries, either of the systemic or pulmonic systems of vessels ; it is only venous blood that is moving.] * [The temperature of the nose of a dog is lowered by the constant evaporation ofthe moisture excreted from its surface; when this secretion is checked in consequence of internal disease, then the nose soon grows hot; and the dryness and heat of this part, both in the dog and other animals, form a common symptom of loss of health, as we have frequently had occasion to observe in the animals in the Zoological Gardens.] f [Although, from the experiments on'vegetables subsequently given, it appears that vital heat is not dependent on a nervous system ; yet it has been shown that the production of heat in warm-blooded animals is modified by the nervous influence. See the Physiological Researches, * On the Influence of the Brain on the action ofthe Heart, and on the generation of Animal Heat.' by B C Brodie, F.R.S., Phil Trans, vol c, p. 36; vol. cii., p. 380; also the experiments of Home and Mayo, Phil. Trans., vol. cxv., p. 7; and by Legallois, Annates de Chimie, t. iv. 1817.] ° X [Here ends the first paper in the 65th vol. of the Phil. Trans. The second communication commences as follows : «In the course of a variety of experiments on animals and vegetables, I have frequently observed that the result of experi- S?nU °ne T kX£ Tk the °fc°nomy of the other, and pointed out some K?i .ST°? J i5 eT there/°re C0lleCted some experiments which relate to the heat and cold of those substances;" and then proceeds as in the ON ANIMALS PRODUCING HEAT. 161 animals. In the course of my experiments, having found variations in the degree of heat and cold in the same experiment, for which I could not account, I suspected that this might arise from some imperfection in the construction of the thermometer. I mentioned to Mr. Ramsden my objections to the common construction of that instrument, and my ideas of one more perfect in its nature, and better adapted to the experiments in which I was engaged. He accordingly made me some very small thermometers, six or seven inches long, not above two-twelfths of an inch thick in the stem, having the external diameter of the ball very little larger than that of the stem, on which was marked the freezing point. The stem was embraced by a small ivory scale, so as to slide upon it easily, and retain any position. Upon the hollow surface of this scale were marked the degrees, which were seen through the stem. By these means the size of the thermometer was very much reduced, and it could be applied to soft bodies with much more ease and certainty, and in many cases in which the former ones could not be conveniently used; I therefore repeated with it such of my former experiments as had not at first proved satisfactory, and found the degrees of heat very different, not only from what I had expected, but also from what I had found by my former experiments with thermometers ofthe common construction. I have observed above, and find it supported by every experiment I have made on the heat and cold of animals, that the more perfect have the greater power of retaining a certain degree of heat, which may be called their standard heat, and allow of much less variation than the more imperfect animals ; however, it will appear from the three experiments which I am now going to relate, that many, if not all of the more perfect, are still incapable of keeping constantly to one degree, but may be altered from their standard heat either by external applications or disease. These variations are much greater below that standard than above it, the perfect animals having a greater power of resisting heat than cold, so that they are commonly near their ultimate heat. Indeed we do not want any other proof of a variation than our own feelings, being all sensible of heat and of cold, which sensations could not be produced without an alteration really taking place in the parts affected; and that alteration could not take place if they did not become actually warmer or colder. I have often cooled my hands to such a degree that I could warm them by immersing them in water just pumped; therefore my hands were really colder than the pumpwater. An increase of absolute heat must alter the texture or position of the parts, so as to produce the sensation which we call heat: and as that heat is diminished, the texture or position of the parts is altered in a contrary way, and, when carried to a certain degree, becomes the cause ofthe sensation of cold. Now these effects could' not take place in either case without an increase or decrease of absolute heat in the part; heat, therefore, in some one of its different 162 HUNTER ON THE ANIMAL CECONOMY. degrees, must be present. I shall not in this place attempt to settle whether heat is a body or matter, or only a property of matter, which appears to me to be merely a difference in terms; for a property must belong to something. When heat is applied to the surface ofthe body the skin becomes in some degree heated according to the application, which may be carried so far as actually to burn the living parts : on the contrary, in a cold atmosphere a man's hand may become so cold as to lose that sensation altogether, and change it for pain. Absolute heat and cold may be carried so far as even to alter the structure of the parts upon which the actions of life depend. As animals being subject to variations in the degrees of heat and cold from external applications are of course, in this respect, affected in some measure like inanimate matter; and therefore, as parts are elongated or recede from the common mass, these effects more readily take place ; for instance, all projecting parts and extremities, more especially toes, fingers, noses, ears, combs of fowls, particularly of the cock, are more readily cooled, and are therefore most subject to be affected by cold. Animals are not only subject to an increase and decrease of heat, similar to inanimate matter, but the transition from one to the other (as far as they admit of it) is nearly as quick. I shall not, however, confine myself to sensation alone, as that is in some degree regulated by habit; for a habit of uniformity in the application of heat and cold to an animal body renders it more sensible of the smallest variation in either; while by the habit of variety it will become, in a proportional degree, less susceptible of all such sensations. This is proved every dv>v, in cold weather, by people who are accustomed to clothe themselves warm. In them the least exposure to cold air, although the effect produced in the skin is perhaps not the hundredth part of a degree, immediately gives the sensation of cold, even through the thickest covering; those, on the contrary, who have been used to go thinly clothed, can bear the variation of some degrees without being sensible of it; of this the hands and feet afford an instance in point, exciting the sensation of cold when applied to another part of the body, without having before given to the mind an impression of cold existing in these parts themselves. The projecting parts and the extremities are those which admit of the greatest change in their degrees of heat and cold without materially affecting the animal or even its sensations. I find that by heat or cold externally applied to such parts, the thermometer may be made to rise or fall"; but not in an equal proportion as when applied to inanimate matter. Nor are the living parts cooled or heated in the same proportion, as appears from the application ofthe thermometerto the skin ; for the cuticle is to be considered as a dead covering capable of receiving greater degrees of heat and cold than the" living parts underneath ; and as it might be suspected that the whole of the variation was in this covering, to remove any such doubt I made the following experiments. ON ANIMALS PRODUCING HEAT. 163 Experiment I. I placed the ball of the thermometer under my tongue where it was perfectly covered by all the surrounding parts; and having kept it there for some minutes, I found that it rose to 97° : yet it rose no higher by being continued there. I then took several pieces of ice, about the size of walnuts, and put them in the same situation, allowing them only to melt in part, that the application of cold might be better kept up, occasionally spitting out the water arising from the solution. Having continued this for ten minutes, I found, on introducing my thermometer, that it fell to 77°; so that the mouth at this part had lost 20° of heat. The thermometer gradually rose to 97° again; but did not in this experi- 'ment sink so low as it would have done in the hand, if a piece of ice had been held in it for the same length of time. Perhaps the surface under the tongue being surrounded with warm parts renders it next to an impossibility to cool it below that degree ; but I rather suspect that such parts as the hand will allow of greater latitude in this respect, from having insensibly acquired the habit of varying the degree of cold, and becoming of course less susceptible of its impressions, and therefore less easily excited. As a further proof that the more perfect animals are capable of varying their heat in some measure according to the external heat applied, 1 shall adduce the following experiments made on the human subject. The mouth being a part so frequently in contact with the external atmosphere in the action of breathing, whatever is put into it may be supposed to be influenced by that atmosphere;, this will always render an experiment made in that part, relative to heat and cold, somewhat uncertain. I imagined that the urethra would answer better, because, being an internal cavity, it can only be influenced by heat and cold applied to the external skin of the parts. I imagined also that, whatever effects the application of heat and cold might have, they would sooner take place in the urethra, as being a projecting part, than in any other part of the body; and therefore, if living animal substance was in any degree subject to the common laws of matter in this respect, the urethra would be readily affected. To determine this 1 procured a person who allowed me to make such experiments as I thought necessary. Experiment II. I introduced the ball of my thermometer into the urethra about an inch ; which having remained there about a minute, the quicksilver rose to 92°; at two inches it rose to 93°; at four inches to 94°; and when the ball had got as far as the bulb of the urethra, where it was surrounded by warm parts, the quicksilver rose to 97°. Experiment III. These parts being immersed for one minute in water, heated only to 65°. and the thermometer introduced about an inch and a half into the urethra, the quicksilver rose to 69°; which was repeated several times with the same result. To discover if there were any difference in the quickness of the transition of heat and cold in living and dead parts, and to determine if the extent to ]64 HUNTER ON THE ANIMAL CECONOMY. which each would go were likewise different, I procured a dead penis, for the purpose of making the comparative experiments that follow; being clearly of opinion that all such trials should be as similar as possible, except in those points where the difference (if there is any) makes the essential part of the experiment. Experiment IV. The heat of the penis of a living person, an inch and a half within the urethra, being found exactly 92°; and the dead one being heated to the same degree, I had both immersed in the same vessel, with the water at 50°, when, by introducing the thermometers several different times, I was able to note the comparative quickness with which they cooled from 92°, and observed that the dead cooled sooner by two or three minutes; the living sunk the quicksilver to 58°, and the dead to 50°: the thermometer, although continued there some time longer, fell no lower. I repeated this experiment several times, with the same result; although at one time there was a small difference in the degrees of heat of the penis and also of the water; but the difference in the result was nearly proportional in all the three different trials, therefore the same conclusions may be drawn from them. In these last experiments very little difference was observed between the cooling of a dead and of a living part; a circumstance which we cannot suppose to take place uniformly through the whole body, as in that case living animals would always be ofthe same degree of heat with the atmosphere in which they live. The subject of these experiments not choosing to have the part cooled lower than 53° or 54°, prevented my observing if the powers of generating heat were exerted to a greater degree when the heat was brought so low as to threaten destruction ; but by some experiments on mice, which will be related hereafter, it will appear that the animal powers are roused to exert themselves in this respect when necessary. Having found, from the above experiments, that parts of an animal were capable of being cooled below the common or natural heat, I proceeded to make others, with a view to ascertain if the same parts were capable of being made much hotter than the standard heat of animals. The experiments were made in the same manner as the former, only the water was now hotter than the natural heat ofthe animal. Experiment V. The natural heat of the parts beinn- 92°, they were immersed for two minutes in water heated to* 113°, and, the thermometer being introduced as before, the quicksilver rose to 100° and a half. This experiment I also repeated several times, but could not raise the heat of the penis beyond 100£°: this was probably owing to the person not being able at the time to bear the application of water warmer than 113°. By was of comparison, I made Experiment VI. The living and dead parts being both immersed in water, gradually made warmer and warmer from 100° to 118Q, and continued in that heat for some minutes, the dead part raised ON ANIMALS PRODUCING HEAT. 165 the thermometer to 114°, while the living raised it no higher than 102i°. It was observed, by the person on whom the experiment was made, that after the parts had been in the water about a minute, the water did not feel hot, but on its being agitated it felt so hot that he could hardly bear it. Upon applying the thermometer to the sides of the living glans, the quicksilver immediately fell from 118° to about 104°, while it did not fall more than a degree when put close to the dead ; so that the living glans cooled the surrounding water to a certain distance.* Experiment VII. The heat of the rectum in the same man was 98° and a half exactly. In the second, third, fourth, fifth, and sixth experiments, an internal cavity, which is both very vascular and sensible, was evidently influenced by external heat and cold, though only applied to the skin of the part; while in the seventh experiment another part of the same body, where external heat and cold could make little or no impression, was of the standard heat. Although it will appear, from experiment, that the rectum is not the warmest part of an animal, yet, in order to determine how far the heat could be increased by stimulating the constitution to a degree sufficient to quicken the pulse, I repeated the seventh experiment after the man had eaten a hearty supper and drank a bottle of wine, which increased the pulse from 73° to 87°, and yet the thermometer only rose to 98° and a half. Having formerly made experiments upon dormice during the sleeping season, with a view to see if there were any alteration in the animal ceconomy at that time, I found among my notes an account of some which appear to our present purpose; -but to be more certain ofthe accuracy ofthe former experiments, I repeated them with my new thermometer. Experiment VIII. In a room, in which the temperature of the air was between 50° and 60°, a small opening was made in the belly of a dormouse, of a sufficient size to admit the ball of my thermometer, which, being introduced into the belly at about the middle of that cavity, rose to 80°, and no higher. Experiment IX. The mouse was put into a cold atmosphere of 15° above 0, and left there for fifteen minutes; after which, the thermometer being introduced a second time, it rose to 85°. Experiment X. The mouse was again put into a cold atmosphere for fifteen minutes; and the thermometer being introduced, the quicksilver at first rose to 72° onlv, but graduallv came up to S3°, 84°, and 85°. Experiment XI. It was put a third time into the cold atmosphere, and allowed to stay there for thirty minutes: the lower part ofthe

* This might furnish an useful hint respecting bathing in water, whether colder or warmer than the heat of the body : for if intended to be either colder or hotter, it will soon be of the same temperature with that of the body; therefore in a laro-e bath the patient should move from place to place, and in a small one there should be a constant succession of water of the intended heat. 166 HUNTER ON THE ANIMAL CECONOMY. mouse, at the bottom of the dish, was almost frozen; the whole of the animal was numbed, and a good deal weakened. The thermometer being introduced, the heat was found to vary in different parts of the belly: in the pelvis, near the parts most exposed to the cold, it was as low as 62°; in the middle, among the intestines, about 70°; but near the diaphragm it rose to 80°, 82°, 84°, and 85°; so that in the middle ofthe body the heat had decreased 10°. Finding a variation in different parts of the same cavity in the same animal, I repeated the same experiments upon another dormouse. Experiment XII. Having brought a healthy dormouse, which had been asleep from the coldness of the atmosphere, into a room in which there was a fire (the atmosphere at 64°), I introduced the thermometer into its belly, nearly at the middle, between the thorax and pubis, and the quicksilver rose to 74° or 75°; turning the ball towards the diaphragm, it rose to 80°; and when I applied it to the liver, it rose to 81 h°- Experiment XIII. The mouse being placed in an atmosphere at 20°, and left there half an hour, when taken out was very lively, even much more so than when put in. Introducing the thermometer into the lower part of the belly, the quicksilver rose to 91°; and upon turning it up to the liver to 93°. Experiment XIV. The animal being replaced in the cold atmosphere at 30° for an hour, the thermometer was again introduced into the belly; at the liver it rose to 93°; in the pelvis to 92°; the mouse continuing very lively. Experiment XV. It was again put back into an atmosphere, cooled to 19°-, and left there an hour; the thermometer at the diaphragm was 87°; in the pelvis 83°; but the animal was now less lively. Experiment XVI. Having been put into its cage, the thermometer being placed at the diaphragm, in two hours Afterwards was at 93°. As I was unable to procure hedgehogs in the torpid state, to ascertain their heat during that period, I got my friend Mr. Jenner,* surgeon, at Berkeley, to make the same experiments on that animal, that I might compare them with those in the dormouse; and his account is as follows : " Experiment I. In the winter, the atmosphere at 44°, the heat of a torpid hedgehog, in the pelvis, was 45°, and at the diaphragm 48^ . r ° "Experiment II. The atmosphere 26°, the heat of a torpid hedgehog, in the cavity of the abdomen, was reduced so low as 30°. « Experiment III The same hedgehog was exposed to the cold atmosphere of 26° for two days, and the heat of the rectum was found to be 93°; the wound in the abdomen being now so small that it would not admit the thermometer. * [Afterwards Dr. Jenner, the discoverer of Vaccination.] ON ANIMALS PRODUCING HEAT. 167 14 A comparative experiment was made with a puppy, the atmosphere at 50°; the heat in the pelvis, as also at the diaphragm, was 102°. " In summer, the atmosphere at 78°, the heat of the hedgehog, in an active state, in the cavity ofthe abdomen, towards the pelvis, was 95°; at the diaphragm 97°."' We find from these experiments, that the heat of the animal is increased under the circumstances of cold, whenever there are actions to be carried on for which heat is necessary. In the experiments on the first dormouse the heat of the animal was 80°, which is below the standard heat of the actions of that animal; and after being put into the cold mixture its heat was raised to 85°. In the second dormouse the heat was raised, by repeated experiments, from 75° to 93°. This question naturally occurs here: Was the increase of heat in the animals generated to resist the artificial cold produced by placing them in a cold atmosphere? or was it owing to a wound having been made into the cavity of the abdomen, and an exertion of the animal powers being required to repair the injury, which exertion could not take place without the increased degree of heat 1 That it was in consequence of the wound, appears evident from the experiment made upon the second hedgehog; for in an atmosphere of 26° of heat it was in a very torpid state, and did not raise the thermometer higher than 30°; but after being wounded and put back into the cold, and kept there for two days, its heat in the rectum was 93°, and so far from being torpid, it was lively, and the bed in which it lay felt warm.* Why the heat ofthe dormouse should be so low as 80°, in an atmosphere of between 50° and 60°, is not easily accounted for, except as the effect of sleep. But I should very much suspect that sleep, simply considered, is out of the question, it being an effect that takes place in all degrees of heat and cold. In animals whose voluntary actions are suspended by cold, that appears to produce its effect by acting in a certain degree as a sedative, in consequence of which the animal faculties are proportionably weakened, though they still retain, even under such circumstances, the power of carrying on all the functions of life. Beyond this point cold seems to act as a stimulant, and rouses the animal powers to action for self-preservation. It is more than probable that most animals are in this predicament, and that there is a degree of cold corresponding with every particular order of animals, by which, when applied, the voluntary actions must be suspended. When a man is asleep he is colder than when awake; and I find in general that the difference is about one degree and a half; sometimes less. But this difference in the degree of cold between sleeping and waking is not a cause of sleep, but an effect; for many diseases produce a much greater degree of cold in the animal

* It is found, from experiments, that ihe heat of an inflamed part is nearly the greatest or standard heat of the animal, it appearing to be a part of the process of inflammation to raise the heat up to the standard. 163 HUNTER ON THE ANIMAL CECONOMY. without giving the least tendency to sleep ; therefore the inactivity of animals from cold must be different from sleep. Besides all the operations of perfect life, as digestion, sensation, &c, are going on in the time of natural sleep, at least in the perfect animals; but none of these operations are performed in the torpid state of animals.* To see if the result of these experiments upon dormice was peculiar to that species, I wished to repeat the same experiments upon common mice, for which purpose, in Experiment XVII. I made use of one strong and vigorous; and the atmosphere being at 60°, I introduced the thermometer into the abdomen ; the ball being at the diaphragm the quicksilver was raised to 90°, but at the pelvis only to 963°. Here there was a real difference of about 9° between the dormouse and the common, the dormouse only raising it to 80°, in two animals'of the same size, in some degree ofthe same genus, and at the same season of the year, and the atmosphere of nearly the same temperature. Experiment XVIII. The same mouse was put into a cold atmosphere of 13° for an hour, and then the thermometer was introduced as before; but the animal had lost heat, for the quicksilver at the diaphragm was raised only to 83°, in the pelvis to 78°. Here the real heat of the animal was diminished 16° at the diaphragm, and 18° in the pelvis, while in the dormouse it gained 5°, but lost upon a repetition. Experiment XIX. In order to determine whether an animal that is weakened has the same powers, with respect to preserving heat and cold, as one that is vigorous and strong, I weakened a mouse

* [Some recent experiments of Dr. Marshall Hall confirm the accuracy of the distinction here drawn between sleep and torpidity, and also show that the ordinary sleep of hybernating warm-blooded animals differs from that of nonhybet tating species, by inducing a more impaired state of the respiration, and a diminjtion ofthe power of evolving of heat. Although a consciousness or sensibility be lost, automatic susceptibility of impressions is remarkably perfect during torpidity. Dr. H^l states that, the slightest touch applied to one of the spines of the torpid hedgehog immediately rouses it to draw a deep sonorous inspiration, which is its characteristic response to such disturbance while in that state. The merest shake induces few respirations in the hybernatingbat. (Phil. Trans., 1832, p. 15.) So also with respect to circulation, this vital operation appears to be performed uninterruptedly, though slowly, during hybernation. M. Prunelle {Annates du Museum, torn, xviii., p. 28), found that "the pulsations of the heart of a bat, which, while it is awake and active amount to 200 in a minute, are reduced to 50 or 55 when it is torpid. Dr. M. Hall, who succeeded, by an ingenious contrivance, in subjecting the wing of a torpid bat to microscopical examination, found the circulation to be slow in the minute arteries and veins; but the beat of the heart was regular, and generally about twenty-eight limes in a minute. {Ibid. p. 17.) The blood which is thus circulated is venous, the respiration being nearly, if not totally, suspended; and its propulsion in this state is explained on the augmented irritability of the muscular system, which is manifested by the double heart of the torpid mammal being stimulated to contract by carbonized blood, like the heart of the cold-blooded and slow-breathing batrachian reptile.] ON ANIMALS PRODUCING HEAT. 169 by fasting, and then introduced the ball of the thermometer into its belly ; the ball being at the diaphragm, the quicksilver rose to 97°; in the pelvis to 95°, being two degrees colder than the strong mouse. The mouse being put into an atmosphere as cold as the other, and the thermometer again introduced, the quicksilver stood at 79° at the diaphragm, and 74° in the pelvis. In this experiment the heat at the diaphragm was diminished 18°, irf the pelvis 21°. This greater diminution of heat in the second than in the first we may suppose proportional to the decreased power of the animal, arising from want of food. To determine how far different parts of other animals than those already mentioned were of different degrees of heat, I made the following experiments upon a healthy dog. Experiment XX. The ball of the thermometer being introduced two inches within the rectum, the quicksilver rose to lOO^0. The chest of the dog was then opened, and a wound made into the right ventricle ofthe heart; and immediately on the ball being introduced, the quicksilver rose to 101° exactly. A wound was next made some way into the substance of the liver, and the ball being introduced, the quicksilver rose to 1001°. It was next introduced into the cavity of the stomach, where it stood exactly at 101°. All these experiments were made within a few minutes. Experiment XXI. The thermometer was introduced into the rectum of an ox, and the quicksilver rose exactly to 99?°. Experiment XXII. This was also repeated upon a rabbit, and the quicksilver rose to 995°. From experiments on mice and upon the dog, it plainly appears that every part of an animal is not of the same degree of heat; and hence we may reasonably infer, that the heat of the vital parts of man is greater than either the mouth, rectum, or the urethra. To determine how far my idea was just, that the heat of animals varied in proportion to their degree of perfection, I made the following experiments upon fowls, which I considered as one remove below what are commonly called quadrupeds. Experiment XXIII. I introduced the ball of the thermometer successively into the intestinum rectum of several hens, and found that the quicksilver rose as high as 103°, 1031°, and in one of them to 104°. Experiment XXIV. I made the same experiments on several cocks, and the result was the same. Experiment XXV. To determine if the heat of the hen was increased when she was prepared for incubation, I repeated the twenty-third experiment upon several sitting or clucking hens; in one the'quicksilver rose to 104°, in another to 1035°, in a third to 103°, as in the twenty-third experiment. Experiment XXVI. I placed the ball of the thermometer under 16 170 HUNTER ON THE ANIMAL CECONOMY. the same hen, in whose rectum the quicksilver was raised to 104°, and found the heat as great as in the rectum. Experiment XXVII. Having taken some of the eggs from under the same hen, where the chick was about three parts formed, I broke a hole in the shell, and, introducing the ball of the thermometer, found that the quicksilver rose to 99£°. In some that were addled I found the heat not so high by two degrees ; so that the life in the living egg assisted in some degree to support its own heat. Is the increase of three or four degrees of heat, which is the difference found between the fowl and the quadruped, for the purpose of incubation ? The heat in the eggs, which was caused and supported by that of the fowls, was not above the standard of the quadrupeds ; and it would probably have been less if the heat of the hen had not been so great. Finding, from the above experiments, that fowls were some degrees warmer than that class commonly called quadrupeds (although certainly less perfect animals), I chose to continue the experiments upon the same principle, and made the following upon those of a still inferior order. The next remove from the fowl being what is commonly called the Amphibia. Experiment XXVIII. I introduced the thermometer into the stomach, and afterwards into the anus of a healthy viper, and the quicksilver rose from 58° (the heat of the atmosphere in which it was) to 68°; so that it was ten degrees warmer than the common atmosphere.* Experiment XXIX. Having ascertained the heat of the water in a pond, in which there were carp, to be 652°, I took a carp out of this water, and having introduced the thermometer into its stomach, the quicksilver rose to 69°; so that the difference between the water and the fish was only 3J°.f Experiment XXX. The heat of the atmosphere at 56; some earthworms were put into a glass vessel, and a thermometer being immersed among them, the quicksilver stood at 584°. This experiment was repeated ; the atmosphere at 55° : and the worms were found to be 57°. Experiment XXXI. The atmosphere at 54°; four black slugs

* [The observations of Gzermack correspond with the above experiment. He found that the difference between the temperature of the animal and that of the surrounding medium was greater in serpents and lizards than in other reptiles. The temperature of a turtle (Chelonia Mydas) was 82° when the surrounding atmosphere was 84°. That of a frog was 48° when the surrounding water was 44°. That of a Proteus was 64°, the surrounding water being 56°.] f [Certain saltwater fishes, as the bonito and thunny, which have the gills supplied with nerves of unusual magnitude, and therefore probably enjoy a more energetic respiration, which have also a very powerful heart, and the quantity of red blood such as to give the muscles a dark red colour, manifest a higher degree of temperature than the white fishes of fresh water, on which Mr. Hunter experimented. Dr. John Davy found that the bonito had a temperature of 99° Fahrenheit when the surrounding medium was 80°.5. See Philos. Trans., 1835.] ON ANIMALS PRODUCING HEAT. 171 were put into a small vessel, and a thermometer immersed among them stood at 55^°. Experiment XXXII. The atmosphere at 56°; three leeches were put into a small glass vessel, and a thermometer immersed among them stood at 57°. This experiment was repeated ; the atmosphere at 54°; when the thermometer stood at 55^°. To see how far the colder animals had a power of preserving their standard heat when exposed to severe cold, I made the following experiments. Experiment XXXIII. A viper, whose heat was 68°, was put into a pan, and the pan into a cold mixture of about 10°; after remaining there about ten minutes had its heat reduced to 37°. Being allowed to stay ten minutes longer, the mixture at 13°, its heat was reduced to 35.° It was continued ten minutes more in the mixture at 20, and its heat was reduced to 31°; nor did it sink lower, its tail beginning to freeze, and the animal now becoming very weak. It may be remarked, that it cooled much slower than many of the animals mentioned in the following experiments. The frog being in its structure more similar to the viper than to either the fowl or fish, I made the following experiments on that animal. Experiment XXXIV. I introduced the ball of the thermometer into its stomach, and the quicksilver stood at 44°. I then put the frog into a cold mixture, and the quicksilver sunk to 31°; the animal appeared almost dead, but recovered very soon: beyond this point it was not possible to lessen the heat without destroying the animal. But its decrease of heat was quicker than in the viper, although the mixture was nearly the same. The next experiments were made on fishes. Experiment XXXV. In an eel, the heat in the stomach, which at first was at 37°, sunk, after it had been some time in the cold mixture, to 31°. The animal at that time appeared dead, but was found to be alive the next day. Experiment XXXVI. In a snail, whose heat was at 44°, it sunk, after it had been put into the cold mixture, to 31°, and then the animal froze. Experiment XXXVII. Several leeches having been put into a bottle, and the bottle immersed in the cold mixture, the ball of the thermometer being placed in the middle of them, the quitksilver sunk to 31°; and by continuing the immersion for a sufficient time to destroy life, the quicksilver rose to 32°, and then the leeches froze. In all these experiments the animals when thawed were found dead. Finding that animals of the imperfect classes will, without life being totally extinguished, admit of their heat being reduced to that point at which the dead solids and fluids freeze, but if sunk much below that, death must be the consequence, I wished therefore to be able to determine to what degree the heat of the animal could be raised. 172 HUNTER ON THE ANIMAL CECONOMY. Experiment XXXVIII. A healthy viper was placed in an atmosphere heated to 108°, and allowed to stay seven minutes; when the heat of the animal in the stomach and anus was found to be 92§°; beyond which it could not be raised in the above state ofthe atmosphere. The same experiment was made upon frogs, with nearly the same result. Experiment XXXIX. An eel, very weak, its heat at 44°, which was nearly that of the atmosphere, was put into water heated to 65°, for fifteen minutes; and, upon examination, it was found of the same degree of heat with the water. Experiment XL. A tench, whose heat was 41°, was put into water at 65°, and left there ten minutes; the ball of the thermometer being introduced both into the stomach and rectum, the quicksilver rose to 55°. These experiments were repeated with nearly the same result. To determine whether life had any power of resisting heat and cold in inferior classes of animals, I made comparative trials between living and dead ones. Experiment XL1. I took a living and a dead tench, and a living and a dead eel, and put them into warm water; they all received heat equally fast: and when they were exposed to cold, both the living and the dead admitted the cold likewise with equal quickness. I had long suspected that the principle of life was not wholly confined to animals, or animal substance endowed with visible organization and spontaneous motion; but supposed that the same principle might exist in animal substances, devoid of apparent organization and motion, when the power of preservation was simply required. I was led to this opinion about twenty years ago, when busied in making drawings of the growth of the chick in the process of incubation. I then observed, that whenever an egg was hatched, the yolk (which is not diminished in the time of incubation) was always perfectly sweet to the very last; and that the part ofthe albumen, which has not been expended on the growth of the animal, some days before hatching, was also perfectly sweet, although both were kept in a heat of 103° in the hen's egg for three weeks, and in the duck's for four; but I observed thai if an egg was not hatched, that egg became putrid in nearly the same time with any other dead animal matter. To determine from other tests how far eggs possessed a living principle, I made the following experiments. Experiment XLII After having placed an egg in a cold about 0, till it froze, I allowed it to thaw; by which process it was to be supposed the preserving powers of the egg must be destroyed. I then put this egg into the cold mixture, and with it one newly laid and found the difference in freezing was seven minutes and a half, the fresh one so much longer time resisting the powers of

Experiment XLIII. A new laid egg being put into a cold atmo- ON ANIMALS PRODUCING HEAT. 173 sphere, fluctuating between 17° and 15°, took above half an hour ■to freeze; but when thawed and put into an atmosphere at 25°, it froze in half the time. This experiment was repeated frequently with nearly the same result. To ascertain the comparative degree of heat between a living and a dead egg, and also to determine whether a living egg be subject to the same laws with the more imperfect animals, I made the following experiments. Experiment XLIV. A fresh egg, and one which had been frozen and thawed, were put into the cold mixture at 15°: the thawed one soon came to 32°, and began to swell and congeal; the fresh one sunk to 291°, and in twenty-five minutes later than the dead one it rose to 32°, and began to swell and freeze. In this experiment the effect on the fresh egg was similar to that produced on the frog, eel, snail, &c, where life allowing the heat to be diminished two or three degrees below the freezing point, afterwards resisted all further decrease; but the powers of life being expended by this exertion, the parts froze like any other dead animal matter. From these experiments it appears that a fresh egg has the power of resisting heal, cold, and putrefaction in a degree equal to many ofthe more imperfect animals; and it is more than probable this power arises from the same principle in both. From the circumstance of those imperfect animals (upon which I made my experiments) varying their heat so readily, we may conclude that heat is not so very essential to life in them as in the more perfect; although it be essential to many of the operations, or what may be called the secondary actions of life, such as digesting food* and propagating the species, both which, especially the last, requiring the greatest powers an animal can exert. The animals which we call imperfect being chiefly employed in the act of digestion, we may suppose their degree of heat to be only what that action requires ; it not being essentially necessary for the life ofthe animal that heat should ever rise so high in them as to call forth the powers necessary for the propagation of the species, f When-

* How far this idea holds good with fishes, I am not certain. f The hedgehog may be called a truly torpid animal; and we find that its actual heat is diminished when the actions are not vigorous.51 From a general a [The experiments by which this important fact was established are those numbered I. and II., page 166. They were made after the publication of the original memoir in the Philosophical Transactions, in which the note consequently commences thus: " How far the animal heat is lowered in the more perfect animals, when these secondary actions are not necessary, as in the bat, hedgehog, bear, &c, I have not been able to determine, not having the opportunities of examining these animals. Dormice are in a mixed state, between the voluntary, and involuntary, and we find the heat diminished when the actions are not vigorous; and, from a general review of this whole subject, it would appear that a certain degree of heat in the animal is necessary for digestion, and that necessary heat will be according to the nature of the animal."—-Phil. Trans. 1778, p. 91. 174 HUNTER ON THE ANIMAL CECONOMY. ever therefore these imperfect animals are exposed to a cold so "reat as to weaken their powers, and disable them from performing the first of these secondary actions, they in some measure cease to be voluntary agents, and remain in a torpid state during that extreme degree of cold which always occurs during some part of the winter in the countries they inhabit; and the food of such animals not being in general produced in the cold season is a reason why this torpidity becomes in some measure necessary.* From the heat of such animals sinking to the freezing point, or even lower, and then becoming stationary, and the animal not being able to support life in a much greater degree of cold for any length of time, we see a reason why they should always endeavour to procure places of abode in the winter where the cold seldom sinks to that point. We find toads burrowing, frogs living under large stones, snails seeking shelter under stones and in holes, and fishes having recourse to deep water; the heat of all those places being generally above the freezing point even in our hardest frosts; which are however sometimes so seVere as to kill many whose habitations are not well chosen. When the frost is more intense and of longer standing than common, or in countries where the winters are always severe, there is generally snow on the ground, and the water freezes: the advantage arising from these two circumstances is great; the snow serving as a blanket to the earth, and the ice to the water.f

review of this whole subject it would appear that a certain degree of heat in the animal is necessary for its various ceconomical operations, among which is digestion ; and that necessary heat will be according to the nature of the animal, and, probably, the nature of the operations to be performed. A frog will digest food when its heat is at 60°, but not when at 35° or 40° ; and it is very probable that, when the heat ofthe bear, hedgehog, dormouse, bat, &c, is reduced to 70°, 75°, or 80°, they lose their power of digestion; or rather that the body, in such a degree of cold, has no call upon the stomach. That animals in a certain degree of heat must always have food is further illustrated by the instance of bees. The construction of a bee is very similar to that, of a fly, a wasp, &c. A fly and a wasp can allow their heat to diminish, as in the fish, snake, &c, without losing life, but a bee cannot; therefore a bee is obliged to keep up its heat as high as what we call its digestive heat, but not its propagating; for which purpose they provide against such cold as would deprive them even of their digestive heat, if they had not food to preserve it. * The torpidity induced by cold in hybernating animals is unlike that which is similarly induced in non-hybernating animals; in the former it is an action of preservation, in the latter one of destruction. See the paper before auoted, bv Dr. Marshall Hall.] r H f Snow and ice are perhaps the worst conductors of heat of any substance yet known. In the first place, they never allow their own heat to rise above the freezing point, so that no heat can pass through ice or snow when at 32°, by which means they become an absolute barrier to all heat that is at or above that degree; hence the heat of the earth, or whatever substance they cover, is retained; but they are conductors of heat below 32°. Perhaps that power decreases in proportion as the heat decreases under that point. In the winter 1776, a frost coming on, the surface of the ground was frozen; but a considerable fall of snow fell, and continued several weeks : the heat of the atmosphere during the time was often at 15°; but so little did the frost affect the ON ANIMALS PRODUCING HEAT. 175 As all the experiments I ever made upon the freezing of animals (with a view to see if it were possible to restore the actions of life when thawed) were tried upon whole ones; as I never saw life return by thawing,* and wished to see how far parts were similar to the whole in this respect, it being asserted, and with some authority, that parts of a man may be -frozen, and afterwards recover,—I made, for this purpose the following experiments upon an animal of the same class as ourselves. In January 1777, I mixed salt and ice till the cold was about 0; in the side of the vessel was a hole, through which I introduced the ear of a rabbit; and, to carry off the heat as-fast as possible, it was held between two flat pieces of iron that went further into the mixture. That part of the ear projecting into the vessel became stiff, and when cut did not bleed ; the part divided by the scissors flying from between the blades like a hard chip. The ear having remained in the mixture nearly an hour, soon thawed when taken out, began to bleed, and became so very flaccid, as to double upon itself, from losing its natural elasticity. When out of the mixture nearly an hour, it became warm: and this warmth increasing to a considerable degree, it also began to thicken, in consequence of inflammation, while the other ear continued in its usual degree of cold. The day following the frozen ear was still warm; and even two days after retained its heat and thickness, which continued for many days after. About a week after this, the mixture being the same as in the former experiment, I introduced the ears ofthe same rabbit through the hole, and froze them both: the sound one however froze first probably from its being considerably colder at the beginning. When withdrawn they soon thawed, both soon became warm, and the fresh ear thickened as the other had done before. Such a change in the parts does not always take place so quickly;

ground underneath that the surface of the ground thawed, and the earth retained the heat of 34°, in which beans and peas will grow. The same thing took place in a pond where the water was frozen on the surface to a considerable thickness: a large quantity of snow having fallen, and covered the ice, the heat of the water was preserved ; the ice thawed, and the snow, at its under surface, was found mixed with the water. The heat of the water under the snow was at 35°, in which fishes lived very well. It would be an attempt worthy the attention of the public philosopher to investigate the cause of the heat of the earth, upon what principle it is preserved, &c. * Vide Phil. Trans, for the year 1775, vol. Ixv. part ii. p. 446.a a That animals, lower in in the scale than any which Hunter experimented on with this view, may, after having been frozen, recover life by thawing, is rendered at least highly probable from the following statement by Rudolphi. In his description ofthe Filaria capsularia, he observes, " Vermis vitae satis tenax est, ut per octiduum in frigida conservaverim, et Filarias in Harengis congelatis rigidas et glacie tectas frigida affusa reviviscere viderirn." (Hist. Entoz.y vol. ii., p. 62. 176 HUNTER ON THE ANIMAL CECONOMY. for on repeating the experiment on the ear of another rabbit till it became as hard as a board, it was found to be longer in thawing than in the former experiment, and much longer before it became warm ; in two hours, however, it had acquired some degree of warmth, and on the day following was hot and thickened. In the spring, 1776, I perceived that my cocks in the country had their combs smooth, with an even edge, and not so broad as formerly, appearing as if near one half of them had been cut off Having inquired into the cause of this, my servant told me that it had happened in that winter during the hard frost, he having then observed that the combs had in part dropped off, also that the comb of one cock had entirely separated: but this I did not see as by accident he was burnt to death. I naturally imputed this effect to the combs having been frozen to so great a degree during the severe weather as to have the life of the part destroyed. To determine, therefore, by experiment, the solidity of this reasoning, I made the following experiment. I selected for the purpose a very large young cock, having a comb of considerable breadth, with deep serrated edges, the processes of which were full half an inch long. My attempts to freeze the substance of the comb did not succeed ; for that, being thick and warm, resisted the effects of the cold, and only the serrated edges were frozen. The frozen parts became white and hard, and when I cut off a little bit did not bleed, nor did the animal show any signs of pain. I next immersed in the cold mixture one of his wattles, which was very broad and thin ; it froze very readily ; and upon thawing both the comb and wattle they became warm, but of a purple colour, having lost that transparency which remained in the other parts ofthe comb and in the other wattle. The wound in the comb now bled freely. Both comb and wattle recovered perfectly in about a month. The natural colour returned first nearest to the sound parts, increasing gradually till the whole had acquired a healthy appearance. There was a very material difference in the effect between those fowls, the serrated edges of whose combs I suspected to have been frozen in the winter of 1775-6, for they must have dropped off. The only way in which I can account for this difference is, that in those fowls the parts were kept so long frozen that the unfrozen or active parts had time to inflame, and had brought about a separation ofthe frozen parts, treating them exactly as dead, similar to a mortified part: and that before they thawed, the separation was so far completed as to deprive them of further support. As it is confidently asserted that fishes are often frozen, and again return to motion, and as I had never succeeded in any of my trials of the kind upon whole fishes, I made some experiments upon particular parts, to which I was led by having found a material difference in the result of experiments made upon the whole, and on parts ofthe more perfect animals. I froze the tail of a tench, as high as the anus, which became as ON THE HEAT OF VEGETABLES. 177 hard as a board : when thawed, that part was whiter than common ; and when it moved, the whole tail moved as one piece, and the termination ofthe frozen part appeared like the joint on which it moved. On the same day I froze the tails of two gold fishes till they became as solid as a piece of wood. They were put into cold water to thaw, and appeared for some days to be very well; but that part ofthe tails which had been frozen had not the natural colour, and the fins of the tails became ragged. About three weeks after, a fur came all over the frozen parts; their tails became lighter, so that the fishes were suspended in the water perpendicularly; they had almost lost the power of motion ; and at last died. The water in which they were kept was New River water, shifted every day, and in quantity about ten gallons. I made similar experiments upon an order of animals still inferior, viz. common earth-worms. I first froze the whole of an earth-worm as a standard; when thawed it was perfectly dead. I then froze the anterior half of another earth-worm; but the whole died. I next froze the posterior half of an earth-worm; the anterior half continued alive, and separated itself from the dead part. From some of these experiments it appears that the more imperfect animals are capable of having their heat and cold varied very considerably, but not according to the degree of heat or cold of the surrounding medium in which they can support life; for they can live in a cold considerably below the freezing point, and yet the living powers of the animal will not allow their heat to be diminished much beyond 32°. Whenever the surrounding cold brings them so low, the power of generating heat takes place; and if the cold is continued, the animals exert this power till life is destroyed; after which they freeze, and are immediately capable of admitting any degree of cold. 15. EXPERIMENTS AND OBSERVATIONS ON VEGE- TABLES, WITH RESPECT TO THE POWER OF PRODUCING HEAT.*

To ascertain whether vegetables could be frozen, and afterwards retain all their properties when thawed, or had the same power of generating heat with animals, I made several experiments. Vegetable juices when squeezed out of a green plant, such as cabbage and spinage, froze in a cold of about 29°; and between 29° and 30°

* [This paper includes those portions of the two communications to the Royal Society, On the Heat of Animals and Vegetables, which were omitted by Hunter in the ' Animal (Economy.' See Phil. Trans., Ixv., 1785, p. 450.] 17S HUNTER ON THE ANIMAL CECONOMY. thawed again, which is about 4° above the point at which the animal juices freeze and thaw. Experiment I. I took a young growing bean, about three inches long in the stalk, and put it into the leaden vessel with common water, and then immersed the whole into the cold mixture. The water very soon froze all around it; however, the bean itself took up a longer time in freezing than the same quantity of water would have done; yet it did freeze, and was afterwards thawed and planted in the ground, but it soon withered. The same experiment was made upon the bulbous roots of tulips, and with the same success. Experiment II. A young Scotch fir, which had two complete shoots and a third growing, and which consequently was in its third year, was put into the cold mixture, which was between 15° and 17°. The last shoot froze with great difficulty, which appeared to be owing in some measure to the repulsion between the plant and the water. When thawed the young shoot was found flaccid. It was planted; the first and second shoot we found retained life, while the third, or growing shoot, withered. Experiment III. A young shoot of growing oats, with three leaves, had one of the leaves put into the cold mixture At 22°, and it soon was frozen. The roots were next put in, but did not freeze; and when put into the ground the whole grew, excepting the leaf which had been frozen. The same experiment was made upon the leaves and roots of a young bean, and attended with the same success. Experiment IV. A leaf taken from a growing bean was put into the cold mixture and frozen, and afterwards thawed, which served as a standard. Another fresh leaf was taken and bent in the middle upon itself; a small shallow leaden vessel was put upon the top of the cold mixture, and the two leaves put upon its bottom; but one half of each leaf was not allowed to touch the vessel by the bend: the cold mixture was between 17° and 15°, and the atmosphere at 22°. The surfaces of the two leaves which were in contact with the lead were soon frozen in both; but those surfaces which rose at right angles, and were therefore only in contact with the cold atmosphere, did not freeze in equal times; the one that had gone through this process before froze much sooner than the fresh one. The above experiment was repeated when the cold mixture was at 25°, 24°, and the atmosphere nearly the same, and with the same success ; only the leaves were longer in freezing, especially tne tresn lest. Experiment V. The vegetable juices above-mentioned being frozen m the leaden vessel, the cold mixture at 28°, and the atmosphere the same, a growing fir-shoot was laid upon the surfaco, also a bean-leaf; and upon remaining there some minutes, they were found to have thawed the surface on which they lay. This I thought might arise from the greater warmth of these substances at the time of application ; but by moving the fir-shoot to another part, we had the same effect produced. ON THE HEAT OF VEGETABLES. 179 Experiment VI. A fresh leaf of a bean was exactly weighed ; it was then put into the cold atmosphere and frozen. In this state it was put back into the same scale, and allowed to thaw. No alteration in the weight was produced. From the foregoing experiments it appears, first, that plants, when in a state of actual vegetation, or even in such a state as to be capable of vegetating under certain circumstances, must be deprived of their principle of vegetation before they can be frozen. Secondly, vegetables have a power within themselves of producing or generating heat; but not always in proportion to the diminution of heat by application of cold, so as to retain at all times an uniform degree of heat; for the internal temperature of vegetables is susceptible of variations to a much greater extent indeed than that ofthe more imperfect animals, but still within certain limits: beyond these limits the principle of vegetable, as of animal life, resists any further change. Thirdly, the heat of vegetables varies according to the temperature of the medium in which they are, which we discover by varying that temperature, and observing the heat of the vegetable. Fourthly, the expense of the vegetating powers in this case is proportioned to the necessity, and the whole vegetable powers may be exhausted in this way. Fifthly, this power is most probably in proportion to the perfection of the plant, the natural heat proper to each species, and the age of each individual. It may also perhaps depend, in some degree, on other circumstances not hitherto observed ; for in Experiment II. the old shoot did not lose its powers, while that which was young or growing did; and in Experiments II. and III. we found that the young growing shoot ofthe fir was with great difficulty frozen at 15°, while a bean-leaf was easily frozen at 22°; and in experiment V. the young shoot of fir thawed the ice at 28° much faster than the leaf of the bean. Sixthly, it is probably by means of this principle that vegetables are adapted to different climates. Seventhly, that suspension of the functions of vegetable life, which takes place during the winter season, is probably owing to their being susceptible of such a great variation of internal temperature. Eighthly, the roots of vegetables are capable of resisting cold more than the stem or leaf; therefore, though the stem be killed by cold, the root may be preserved, as daily experience evinces. The texture of vegetables alters very much by the loss of life, especially those which are watery and young; from being brittle and crisp, they become tough and flexible. The leaf of a bean when in full health is thick and mossy, repels wafer as if greasy, and will often break before it is considerably bent; but if it is killed slowly by cold, it will lose all these properties, becoming then pliable and flaccid : deprived of its power of repelling water, it is easily made wet, and appears like boiled greens. If killed quickly by being frozen immediately, it will remain in the same state as when alive; but upon thawing, will immediately lose all its former texture. This is so remarkable, that it would induce one to believe that it lost considerably of its sub- 180 HUNTER ON THE ANIMAL CECONOMY. stance; but from Experiment VI. it is evident that it does not. The same thing happens to a plant when killed by electricity.* If a growing juicy plant receives a stroke of electricity sufficient to kill it, its leaves droop, and the whole becomes flexible. So far animal and vegetable life appear to be the same; yet an animal and a vegetable differ in one very material circumstance, which it may be proper to take particular notice of in this place, as it shows itself with remarkable evidence in these experiments. An animal is equally old in all its parts, excepting where new parts are formed in consequence of diseases ; and we find that these new or young parts in animals, like the young shoots of vegetables, are not able to support life equally with the old ; but every plant has in it a series of ages. According to its years, it has parts of all the successive ages from its first formation; each part having power equal to its age, and each part, in this respect, being similar to animals of so many different ages. Youth, in all cases, is a state of imperfection; for we find that few animals that come into the wrorld in winter live, unless they are particularly taken care of; and we may observe the same of vegetables. I found that a young plant was more easily killed than an old one; as also the youngest part ofthe same plant. fAs I had formerly, in making my experiments upon animals relative to heat and cold, made similar ones on vegetables, and had generally found a great similarity between them in these respects, I was led to pursue the subject on the same plan; but I was still further induced to continue my experiments upon vegetables, as I imagined I saw a material difference between them in their power of supporting cold. From observations and the foregoing experiments, it plainly appears that the living principle will not allow the heat of such animals to sink much lower than the freezing point, although the surrounding atmosphere be much colder, and that in such a state they cannot support life long; but it may be observed, that most vegetables of every country can sustain the cold of their climate. In very cold regions, as in the more northern parts of America, where the thermometer is often 50° below 0, where people's feet are known to freeze and their noses to drop off if great care be not taken, yet the spruce-fir, birch, juniper, &c, are not affected. Yet, that vegetables can be affected by cold, daily experience evinces; for the vegetables of every country are affected if the season be more than ordinarily cold for that country, and some more than others; for in the cold climates above mentioned the life of the vegetable is often obliged to give way to the cold of the country: a tree shall die by the cold ; then freeze and split into a great number of pieces; and in so doing produce considerable noise, giving loud cracks, which are often heard at a great distance.

rtr*mL° J"1!,* w°le Phnt by- e¥tri(%> it is necessary to apply the conductor, SiS wiiutuT 2 EST"8 part; for any part that is out of the line of t [See Phil. Trans., lxviii., 1778, p. 38.] ON THE HEAT OF VEGETABLES. 181 In this country the same thing sometimes happens to exotics from warmer climates. A remarkable instance of this kind happened this winter in His 'Majesty's garden at Kew. The Erica arborea, or tree-heath, a native of Spain and Portugal, which had kept its health extremely well against a garden wall for four or five years, though covered with a mat, was killed by the cold, and then, being frozen, split into innumerable pieces.* But the question is, Is every tree dead that is frozen ? I can only say, that in all the experiments I ever made upon trees and shrubs, whether in the growing or active state, or in the passive, that whole or part which was frozen was dead when thawed. The winter 1775-6 afforded a very favourable opportunity for making experiments relative to cold, which I carefully availed myself of. However, previous to that winter, I had made many experiments upon vegetables respecting their temperature, comparatively with that of the atmosphere, and when they were in their different states of activity : I therefore examined them in different seasons, with a vievy, to see what powers vegetables have. I shall relate these experiments in the order in which they' were made. They were begun in the spring, the actions of life upon which growth depends being then upon the increase; and they were continued till those actions were upon the decline, and also when all actions were at an end, but whilst the passive powers of life were still retained. The first were made on a walnut-tree, nine feet high in the stem, and seven feet in circumference in the middle. A hole was bored into it on the north side, five feet above the surface of the ground, eleven inches deep towards the centre of the tree, but obliquely upwards, to allow any sap, which might ooze through the wounded surface to run out. I then fitted to this part a box, about eight inches wide and five deep, and fastened it to the tree: the bottom of the box opened like a door with a hinge. I stuffed the box with wool, excepting the middle, opposite to the hole in the tree ; for this part I had a plug of wool to stuff in, which, when the door was shut, inclosed the whole. The intention of this was to keep off, as much as possible, all immediate external influence either of heat or cold. The same thermometer with which I made my former experiments, seven inches and a half long, was sunk into a long feather of a peacock's tail, with a slit upon one side to show the degrees;

* This must be owing to the sap in the tree freezing, and occupying a larger space when frozen than in a fluid state, similar to water; and that there is a sufficient quantity of sap in a tree newly killed, is proved by the vast quantity that flows out on wounding a tree. But what appeared most remarkable to me was, that in a walnut-tree, on which I made many of my experiments, I observed that more sap issued out in the winter than in the summer. In the summer, a hole being bored, scarcely any came out, but in the winter it flowed out abundantly. 17 182 HUNTER U« THE ANIMAL CECONOMY. by this means the ball of the thermometer could be introduced into the bottom of the hole. Experiment 1. March 29. I began my experiments at six in the morning, the atmosphere at 57£°, the thermometer in the tree at 55°; when it was withdrawn the quicksilver sunk to 53, but soon rose to 572°.* This experiment was repeated three times with the same success. Here the tree was cooler than the atmosphere, when one should rather have expected to find it warmer, since it could not be supposed to have as yet lost its former day's heat. Exp. II. April 4th, half-past five in the evening. The tree at 56°, the atmosphere at 62°; the tree therefore still cooler than the atmosphere. Exp. III. April 5th. Wind in the north, a coldish day, six o'clock in the evening; the thermometer in the tree was at 55°, the atmosphere at 47°; the tree warmer than the atmosphere. Exp. IV. April 7th, a cold day, wind in the north, cloudy. At three in the afternoon the thermometer in the tree was at 42°, the atmosphere at 42° also. Exp. V. April 9th, a cold day, with snow, hail, and wind in the north-east. At six in the evening the thermometer in the tree at 45°, the atmosphere at 39°. Here the tree was warmer than the atmosphere, just as might have been expected. If these experiments prove anything, it is that there is no standard ; and probably these variations arose from some circumstance which had no immediate connexion with the internal powers of the tree; but it may also be supposed to have arisen from a power in the tree to produce or diminish heat, as some of them were in opposition to the atmosphere. After having endeavoured to find out the comparative heat between vegetables and the atmosphere when the vegetables were in action, I next made my experiments upon them when they were in the passive life. As the difference was very little when in their most active state, I could expect but very little when the powers of the plant were at rest. From experiment upon the more imperfect classes of animals it plainly appears, that although they do not resist the effects of extreme cold till they are brought to the freezing point, they then appear to have the power of resisting it, and of not allowing their cold to be brought much lower. To see how far vegetables are similar to those animals in this respect, I made several experiments: I however suspected them not to be similar, because such animals will die in a cold in which vegetables do live; I therefore supposed that there was some other principle.

* The sinking of the quicksilver upon being withdrawn I imputed totheevapoating ofthe moisture of the fluid upon the ball. ON THE HEAT OF VEGETABLES. 183 I did not confine these experiments to the walnut-tree, but made similar ones on several trees of different kinds, as pines, yews, poplars, &c, to see what was the difference in different kinds of trees. The difference proved not to be great, not above a degree or two : however, this difference, although small, shows a principle in fife, all other things being equal; for as the same experiments were made on a dead tree, which stood with its roots in the ground, similar to the living ones, they became more conclusive. In October I began the experiments upon the walnut-tree when its powers of action were on the decline, and when it was going into its passive life. Exp. VI. October rsth, at half-past six in the morning, the atmosphere at 511°, the thermometer in the tree was at 553°; but, on withdrawing and exposing it for a few minutes in the common atmosphere, it fell to 50§°. Exp. VII. October 21st, seven o'clock in the morning, the atmosphere at 41°, the tree at 47°. Exp. VIII. October 21st, in the evening at five o'clock, the atmosphere at 51i°, the tree at 57°. Exp. IX. October 22d, at seven in the morning, the atmosphere at 42°, the tree at 48°. Exp. X. October 22d, one o'clock afternoon, the atmosphere at 51°, the tree at 53°. Exp. XI. October 23d, in the evening of a wet day, the atmosphere at 46°, the tree at 48°. Exp. XII. October 28th, a dry day, the atmosphere at 45°, the tree at 46°. Exp. XIII. October 29th, a fine day, the atmosphere at 45°, the tree at 49°. Exp. XIV. November 2d, wind east, the atmosphere at 43°, the tree at 43°. Exp. XV. November 5th, wet day, the atmosphere at 43°, the tree at 45°. Exp. XVI. November 10th. Atmosphere at 49°, the tree at 55°. Exp. XVII. November 18th. Atmosphere at 42°, the tree at 44°. Exp. XVIII. November 20th, fine day, the atmosphere at 40°, the tree at 42°. Exp. XIX. December 2d. The atmosphere at 54°, the tree at 54°. In all these experiments, which were made at various times in the day, viz., in the morning, at noon, and in the evening, the tree was in some degree warmer than the atmosphere, excepting in one, when their temperatures were equal. For the sake of brevity, I have drawn up my other experiments (which were made on different trees) into four tables, as they were made at four different degrees of heat of the atmosphere, including those made in the time of the very hard frost in the winter of 1775-6. They were as follows: 184 HUNTER ON THE ANIMAL 03CONOMY. Table I. ------------------, . ... r- — Dia- Atmo3phere. Nara.es. Height. meter. Heat. ft. in. ft. in. • ["Carolina poplar..... 2 0 0 2 29j English poplar . ., . 4 0 0 2\ 294 Oriental plane . 3 0 o H 30 Occidental plane . . 3 6 0 2 30 Carolina plane . 1 0 0 If 30 Birch . . 3 6 0 2£ 2S94 29 deg. -^ Scotch fir * 3 6 0 4 284 Cedar of Lebanon . . 2 2 0 44 284 Arbutus , 2 6 0 34 30 Arbor vitas . 2 8 0 34 29 Deciduous cypress , 3 0 0 34 30 Lacker varnish , , 3 6 0 2 30 1 ..Walnut-tree . * 5 0 2 4 31 The old hole in the walnut tree, being full of sap, was frozen up; but a new one was made.

Table II. Dia- Atmosphere. Names. Height. meter. Heat. ft. in. in. 0 f Spruce fir..... 4 0 2h 32 Scotch fir . 1 5£ n 28 Silver fir . 3 11 2* 30 Weymouth fir . 4 6 2h 30 27 deg. ■> Yew 3 7 3 30 Holly 2 6 2 30 Plum-tree . . 4 6 3 ■il\ Dead cedar 3 11 3 29 ^Ground under snow 0 3 deep. . . . 34 Table III. Atmosphere. Names. Heat. ("Spruce fir o 23 1 Scotch fir ... 23 1 Silver fir ... 23 24 deg. <( Weymouth fir . 23 | Yew 22 1 Holly 23 LDead cedar .... 24 The same trees we mentioned when the thermometer was at 29°, in new holes made at the same height, and left some time pegged up till the heat produced by the gimlet was gone off; but in which, as they were moist from the sap, the heat could be very little, especially as the gimlet was not in the least heated by the operation. OF PERSONS APPARENTLY DROWNED. 185 Table IV. Atmosphere. Names. Heat. rCarolina poplar o 17 1 English poplar 17 | Oriental plane 17 16 deg. <( Occidental plane 17 1 Carolina plane . . 17 | Birch .... 17 ^Scotch fir . . 16£ It will be necessary to observe, that the sap of the walnut-tree, which flowed out in great quantity, froze at 32°. I did not try to freeze the sap of the others. Now since the sap of a tree when taken out freezes at 32°; also, since the sap of a tree, when taken out of its proper canals, freezes when the heat ofthe tree is at 31°; and since the heat of the tree can be so low as 17°, without freezing; by what power are the juices of the tree, when in their proper canals, kept fluid in such a cold ? Is it the principle of vegetation 1 Or is the sap inclosed in such a way as that the process of freezing cannot take place, which we find to be the case when water is confined in globular vessels? If so, its confinement must be very different from the confinement of moisture in dead vegetables ; but the circumstance of vegetables dying with the cold and then freezing appears to answer the last question. These, however, are questions which at present I shall not endeavour to solve. I have made several experiments upon the seeds of vegetables similar to those on the eggs of animals; but as inserting them would draw out this paper to too great a length, I will reserve them for another. 16. PROPOSALS FOR THE RECOVERY OF PERSONS APPARENTLY DROWNED.*

Having been requested by a principal member of the society established for the recovery of persons apparently drowned to commit my thoughts on that subject to paper, I readily complied, hoping, that although I have had no opportunities of making actual experiments upon drowned persons, it might be in my power to throw some lights on a subject so closely connected with the inquiries which for many years have been my business and favourite amusement: I therefore collected together rny observations and experiments relative to the loss and recovery of the actions of life which I now offer to the public. The endeavour to recover per-

* [From the Philosophical Transactions, vol. lxvi.; read March 21, 1776 1 17* 'J 186 HUNTER ON THE ANIMAL CECONOMY.

sons apparently drowned is a new practice, and has furnished, as yet, few important and clear facts: our knowledge of the animal ceconomy is so imperfect, that I am afraid our reasoning from that alone must not be relied on in a question so interesting to the cause of humanity. But let us reason as well as we can from the few data we have, and let every man bring forward, freely, the observations he has made, that the subject thus fairly before the public may in time, by its united efforts, be more perfectly understood. I shall consider an animal apparently drowned as not dead, but that only a suspension of the actions of life has taken place. The difference between a suspension of the actions of life and absolute death is well illustrated by the common snail when drowning. If a snail is immersed in water and kept there, certain voluntary and instinctive actions take place; but after remaining a certain time covered by the water, all these actions cease. Hence the animal, being relaxed, naturally comes out of the shell in that state; its stomach is filled with water, and the body appears larger than natural, but without motion. These actions continue thus suspended till either the cause of suspension be removed or some other stimulus shall bring the parts into action : but under such circumstances life cannot be preserved for any considerable length of time; and when the stimulus which precedes death takes place, the whole animal is thrown into action, and in that contracted state, possibly, absolute death is produced. A state of relaxation should therefore (where an universal violence has not been committed), be considered as the criterion of life; and even in such cases should be for some time admitted as a probable reason for supposing life still to exist. If an animal appears so far dead as to have lost all the actions characteristic of life, yet a certain degree of action in all the parts will be produced when absolute death is taking place; and that animal, being still susceptible of stimulus, is recoverable if the proper stimulus could Le applied. It is asserted that men have recovered the actions of life even after the contraction, in consequence of the stimulus which precedes death, has taken place. If this be true, which I very much doubt, the stimulus must first produce relaxation, which is an action dependent on life. This is probably the case in the first appearances of death from all violent accidents, except those caused by lightning, electricity, an universal shock, a blow on the stomach, a violent affection of the mind, or some other modes by which absolute death may be instantaneously produced, which all appear to act in the same way, producing absolute and instant death. For in cases which have fallen under my observation, the concomitant circumstances have resembled those which attend death caused by lightning or electricity, such as a total and instantaneous privation of sense and motion without convulsions; consequently, no rigor of muscles having been produced, and the blood remaining uncoagulated, differing OF PERSONS APPARENTLY DROWNED. 187

entirely in these respects from what appears in persons deprived of sense and life by any injury done the brain. It seems only possible to account for this effect of a blow on the stomach, from the connexion subsisting between that viscus and every part of the body, at least with vital parts; the blow most probably causing instant death in that organ of which the death ofthe whole animal is the consequence.* When death takes place from violent affections ofthe mind, it must be referred to the universal influence which the mind has over the body. To ascertain when a body is deprived of life it is first necessary to know in what manner apparent death took place; whether in the common way, or from the vital actions being too long suspended. In either case stiffness of the muscles is probably the most certain and most evident proof of absolute death, since that arises from the stimulus immediately preceding death, having taken place. But if the privation of life is produced by any ofthe modes above mentioned, which kill instantaneously and universally, the stimulus which produces stiffness is not allowed time to act, and the muscles are all left in a relaxed state. Yet this state of relaxation must not, on that account, be always considered as a proof of life still remaining. A degree of flaccidity in the eyeballs, which produces glassiness, is a certain mark of death ; but is, however, only a secondary mode of ascertaining it in those instances where the body becomes stiff; but may be the first mode where absolute death takes place instantaneously ; and putrefaction will be the second ; while in the other cases putrefaction will be the third. That I may more fully explain my ideas upon this subject, it will be necessary to state some propositions. First; that so long as the animal retains the susceptibility of impression, though deprived of the action of life, it will, most probably, retain the power of action when impressed; therefore the action may frequently be suspended, and yet recoverable; but when the susceptibility of impression is destroyed, the action ceases to be recoverable. Secondly; it is necessary to mention, that I consider part of the living principle as inherent in the blood.f Thirdly ; that the stomach sympathizes with every part of an animal, and that

* I should consider the situation of a person drowned to be similar to that of a person in a trance. In both the action of life is suspended without the power being destroyed ; but I am inclined to believe that a greater proportion of persons recover from trances than from drowning, because a trance is the natural effect of a disposition in the person to have the action of life suspended for a time; but drowning being produced by violence, the suspension will more frequently last for ever, unless the power of life is roused to action by some applications of art. t That the living principle is inherent in the blood is a doctrine which the nature of this account will not allow me to discuss ; thus much, however, it may be proper to say, that it is founded on the result of many observations and experiments. But it may be thought necessary I should here give a definition of what I call the living principle: so far, then, as I have used the term, I mean to express that principle which preserves the body from dissolution with or without action, and is the cause of all its actions. j88 HUNTER yj^ xnu ^nnviAJLi w^viwmx.

every part sympathizes with the stomach ; therefore, whatever acts upon the stomach as a cordial, or rouses its natural and healthy actions, and whatever affects it so as to produce debility, has an immediate effect upon every part of the body- The last proposition I have to make is, that every part of the body sympathizes with'the mind; for whatever affects the mind, the body is affected in proportion. These sympathies are strongest with the vital parts; but besides these universal sympathies between the stomach, the mind, and all parts of the body, there are peculiar sympathies, of which the heart, sympathizing immediately with the lungs, is an instance. If anything is received into the lungs which is a poison to animal life, such as inflammable air, volatile vitriolic acid, and many other well-known substances, the motion of the heart immediately ceases, even much sooner than if the trachea had been tied; and, from experiments, it appears that anything salutary to life, applied to the lungs, will restore the heart's action after it has been at rest some time. I shall divide violent deaths into three kinds ; first, where a stop is put only to the action of life in the animal, but without any irreparable injury to a vital part, which action, if not restored in a certain time, will be irrecoverably lost. The length of that time is subject to considerable variation, depending on circumstances with which we are at present unacquainted. The second is, where an injury is done to a vital part, as by taking away blood till the powers of action are lost; or by a wound or pressure being made on the brain or spinal marrow while life remains in the solids sufficient for the preservation of the animal, if action could be restored to the vital parts. The third is, where absolute death instantly lakes place in every part, as is often the case in strokes of lightning; in the common method of killing eels, by throwing them on some hard substance, in such manner as that the whole length of the animal shall receive the shock at the same instant; by a blow on the stomach; by violent affections of the mind; and by many diseases, in all which cases the muscles remain flexible.* How far that maybe strictly considered as a violent death which is caused by affections of the mind, I will not pretend to say; but if it is to have a place in that class, it must be ranked with those which happen from lightning, and a blow on the stomach; and in most cases of persons drowned, I can easily conceive the mind to be so much affected prior to the immersion, and in the moment immediately succeeding it, as to make a material difference in the power of recovery. In many sudden deaths arising from violence, and even from disease, death shall take place so immediately that the muscles neither contract, nor does the blood coagulate.

* On the other hand, when an eel is killed by chopping it into a number, of pieces, the powers of life are by those means roused into action ; and as every part dies in that active state, every part is found stiff after death. This explains the custom of cutting fish into pieces while yet alive, in order to make them hard, usually known by the name of crimping. OF PERSONS APPARENTLY DROWNED. 189 The present consideration is, under which of the kinds of violent death drowning can be classed or arranged 1 I am of opinion it will most commonly come under the first, and upon that ground I shall principally consider the subject, always supposing the body to remain flaccid. The loss of motion in drowning seems to arise from the loss of respiration, and the immediate effects which that has upon the other vital motions ofthe animal; except what may have arisen from the affections of the mind. The privation of breathing appears, however, to be the first cause, and the heart's motion ceasing, to be the second or consequent; therefore most probably the restoration of breathing is all that is necessary to restore the heart's motion; for if sufficient life still exists to produce that effect, we may suppose every part equally ready to move the very instant in which the action of the heart takes place, their actions depending so much upon it. What makes it very probable, that in recovering persons drowned, the principal effect depends upon air being thrown into the lungs, is what happens at the birth of children, when too much time has intervened between the interruption of that life which is peculiar to the foetus and that which depends on breathing; they then lose altogether the disposition for this new life; and in such cases, there being a total suspension of the actions of life, the child remains to all appearance dead, and would certainly die if air were not thrown into its lungs, and by such means the first principle of action restored. To put this in a still clearer light, I will give the result of some experiments which I made in the year 1755 upon a dog. A pair of double bellows were provided, constructed in such a manner as by one action to throw fresh air into the lungs, and by another to suck out again the air which had been thrown in by the former, without mixing them together. The muzzle of these bellows was fixed into the trachea of a dog, and by working them he was kept perfectly alive. While this artificial breathing was going on I took off the sternum ofthe dog,and exposed the lungs and heart; the heart continued to act as before, only the frequency of its action was considerably increased. When I stopped the motion of the bellows the heart became gradually weaker, and less frequent in its contractions, till it entirely ceased to move. By renewing the action of the bellows the heart again began to move, at first very faintly, and with long intermissions ; but by continuing the artificial breathing, its motion became as frequent and as strong as at first. This process I repeated upon the same dog ten times, sometimes stopping for five, eight, or ten minutes, and observed that every time I left off working the bellows the heart became extremely turgid with blood, the blood in the left side becoming as dark as that in the right, which was not the case when the bellows were working. These situations of the animal appeared to me exactly similar to drowning. Death in persons drowned has been accounted for by supposing J90 HUNTER ON THE ANIMAL 02CONOMY.

that the blood, rendered unfit for the purposes of life by being deprived of the action of the air in respiration, is sent in a vitiated state to the brain and other vital parts, by which means the nerves lose their effect upon the heart, and the heart in consequence its motion. This, however, I am fully convinced is false; first, from the experiments on the dog, in which a large column of blood so vitiated (consisting of what had been propelled from the heart after respiration stopped, and might be supposed the cause of the heart ceasing to act, together with all that remained in the heart and pulmonary veins), was again pushed forward without any ill effect having been produced; and next, from the return to life of persons drowned and children still-born, which, were such a supposition true, could never happen, unless we imagine a change of the blood to take place in the brain, prior to the restoration of the heart's motion. This restoration must therefore depend immediately on the application of air to the lungs, and not on the effects which air has upon the blood, or that blood upon the vital parts. If the affections ofthe mind have had any share in the cessation of action in the heart, its motion will not be so easily restored as in other cases. In our attempts to recover those who have been drowned, it might therefore be proper to inquire if there had been time sufficient for the person to form any idea of his situation previous to his being plunged into the water, as it is not unlikely that the agitated state of mind might assist in killing him; and in such case I should very much doubt the probability of restoring him to life. In the history of those who have and who have not been recovered, could the difference be ascribed to any such cause, it might lead to something useful; as in those who have had an intention to destroy themselves, a great difference in the chance of recovery may arise, from the mind having been previously very much affected. It frequently happens, in the case of drowning, that assistance cannot be procured till a considerable time after the accident; every moment of this delay renders recovery more precarious, the chances of which are not only diminished in the parts where the first powers of action principally reside, but also in every other part of the body. In offering my sentiments on the method of treating persons who are apparently drowned, I shall say, first, what I would recommend to have done; secondly, what I would wish might be avoided. When assistance is called in soon after the immersion, perhaps blowing air into the lungs may be sufficient to effect a recoveryr* but if a considerable time, as an hour, has been lost, it will seldom be sufficient, the heart in all probability having by that time lost its * * Perhaps the dephlogisticated air described by Dr. Priestly (oxygen gas) may prove more efficacious than common air. It is easily procured, and may be preserved in bottles or bladders for that purpose. OF PERSONS APPARENTLY DROWNED. 191 intimate connexion with the lungs. It will in these cases, therefore, be proper to apply, mixed with the air, such stimulating medicines as the vapour of volatile alkali, which may easily be done, by holding spirits of hartshorn in a cup under the receiver of the bellows. I would advise the air and volatile alkali to be thrown in by the nose rather than the mouth, as the last mode of administering, by producing sickness, is more likely to depress than rouse the living principle. It will be still better if it can be done by both nostrils, as applications of this kind to the olfactory nerves certainly rouse the living principle and put the muscles of respiration into action, and therefore are the more likely to excite the action of the heart: besides, that affections of these nerves are known to act more immediately on the living principle; since while a strong smell of very sweet flowers, as orange flowers, will in many cause fainting, the application of vinegar will as immediately restore the powers to action again. All perfumes in which there is some acid rather rouse than depress, as the sweet-brier, essence of lemon, &c. If, during the operation of the bellows, the larynx be gently pressed against the oesophagus and spine, it will prevent the stomach and intestines being too much distended by the air, and leave room for the application of more effectual stimuli to those parts. This pressure, however, must be conducted with judgment and caution, so that the trachea and the aperture into the larynx may both be left perfectly free. While this business is going on an assistant should prepare bedclothes, carefully brought to the proper degree of heat. I consider heat as congenial with the living principle; increasing the necessity of action, it increases action ; cold, on the other hand, lessens the necessity, and of course, the action is diminished : to a due proportion of heat, therefore, the living principle owes its vigour; and, from observations and experiments, it appears to be a law of Nature in animal bodies, that the degree of external heat should bear a proportion to the quantity of life ; when it is weakened, this proportion requires great accuracy in the adjustment, while greater powers of life allow a greater latitude.* I was led to make these observations by attending to persons who are frost-bitten, the effect of cold in such cases being that of lessening the living principle. The powers of action remain as perfect as ever, but weakened, and heat is the only thing wanting to put these powers into action : yet that heat must at first be gradually applied, and proportioned to the quantity of the living principle, which increasing, the degree of heat may likewise be increased. If this method is not observed, and too great a degree of heat is at first applied, the person or part loses entirely the living principle, and mortification ensues. Such a process invariably takes place

* It is upon these principles that cold air is found of so much service to people who are reduced by disease, as the confluent small-pox and fevers, by diminishing heat in proportion to the diminution of life, or lessening the necessity of the body's producing its own cold. 192 HUNTER ON THE ANIMAL CECONOMY. with reo-ard to men, and the same thing, I am convinced, happens to other animals. For if an eel is exposed to a degree of cold sufficiently intense to benumb it till the remains of life are scarcely perceptible, and still retained in a cold of about 40°, this small proportion of living principle will continue for a considerable time without diminution or increase; but if the animal is afterwards placed in a heat about 60°, after showing strong signs of returning life, it will die in a few minutes. JSor is this circumstance peculiar to the diminution of life by cold. The same phenomena take place in animals which have been very much reduced by hunger. If a lizard or snake, when it goes to its autumnal hiding-place, is not sufficiently fat, the living powers are, before the season permits it to come out, very considerably weakened ; perhaps so much as not to admit ofthe animal being again restored. If animals in a torpid state are exposed to the sun's rays, or placed in any situation which by its warmth would give vigour to those of the same kind possessed of a larger share of life, they will immediately show signs of increased life, but quickly sink under the experiment and die ; while others, reduced to the same degree of weakness, as far as appearances can discover, will live for many weeks, if kept in a degree of cold proportioned to the quantity of life they possess. I observed, many years ago, in some of the colder parts of this island, that when intense cold had forced blackbirds or thrushes to take shelter in outhouses, such of them as had been caught, and were, from an ill-judged compassion, exposed to a considerable degree of warmth, died very soon. The reason of this I did not then understand; but I am now satisfied that it was owing, as in other instances, to the degree of heat being increased too suddenly for the proportion of life remaining in the animal. From these facts it appears that warmth causes a greater exertion of the living powers than cold; and that an animal in a weakly state may be obliged by it to exert a quantity of the action of life sufficient to destroy the very powers themselves.* The same effects probably take place even in perfect health; it appearing, from experiments made in a heated room, that a person in health, exposed to a great degree of heat, found the actions of life accelerated so much as to produce at last faintness and debility.f If bedclothes are put over the drowned person, so as scarcely to touch him, steam of volatile alkali, or of warm balsams and essential oils, may be so conveyed as to come in contact with many parts of his body; and it will certainly prove advantageous if the same kind of steams can be conveyed into the stomach, as that seat of universal sympathy will be roused by such means. This may be done by a hollow bougie and a syringe; but the operation should be performed with all possible expedition, because the instrument, by continuing in the mouth, may produce sickness, an

• It is upon this principle that parts mortify in consequence of inflammation. | Vide Phil. Trans, for the year 1775, vol. Ixv., p. 111. OF PERSONS APPARENTLY DROWNED. 193 effect I should choose to avoid, unless it is intended to produce the action of vomiting. Some of the stimulating substances, which are of a warm nature and have an immediate effect, as spirits of hartshorn, peppermint-water, juice of horse-radish, and many others which produce a more lasting stimulus in a fluid state, and are found to quicken the pulse of a man in health, as balsams and turpentines, may be thrown into the stomach; but the quantity must be small, as they have a tendency to produce sickness; for it may be imagined that what would produce debility, or lessen action when in health, would in opposite circumstances prevent actions from taking place. The application of steams and other substances should also be thrown up by the anus; and the process recommended under the-first head of treatment should still be continued while that recommended under the second is putting in practice, the last being only an auxiliary to the first. The first, in many cases, may succeed alone; but the second without the first must, I think, always fail where the powers of life are considerably weakened. Motion may possibly be of service, it may at least be tried; but, as it has less effect than any other of the usually prescribed stimuli, it should be the last applied.* I would recommend to the operator the same care in regulating the application of every one of these methods as I did before in that of heat, as each may have the same property of entirely destroying the feeble action which they have excited, if administered in too great a proportion. Instead, therefore, of increasing and hastening the operations on the first signs of returning life being observed, as is usually done, I should wish them to be applied more gently and gradually, that their increase afterwards may be directed, as nearly as possible, in a degree proportioned to the powers as they arise. As the heart is commonly the last part that ceases to act, it is probably the first part that takes on the action of recovery. When it begins to move, I would advise lessening the application of air to the lungs, and enjoin those employed to observe with great attention when the muscles of respiration begin to act, that our endeavours may not interfere with their natural exertions, yet that we maybe still ready to assist. I would by all means discourage bloodletting, which I think weakens the animal principle and life itself, consequently lessens both the powers and dispositions to action; and I would advise being careful not to call forth any disposition that might depress, by introducing things into the stomach which ordinarily create nausea ; as that also will have a similar effect, except it can be carried so far as to excite the action of vomiting, by which the stomach could relieve itself. It will be prudent likewise to avoid

* Electricity has been known to be of service, and should be tried when other methods have failed. It is probably the only method we have of immediately stimulating the heart; all other methods being more by sympathy. I have not mentioned injecting stimulating substances directly into the veins, thouglT it might be supposed a proper expedient, because, in looking over my experiments on that subject, I found none where animal life received increase by that method. 18 194 HUNTER ON THE ANIMAL CECONOMY.

administering by the anus anything that may be likely to produce an evacuation that way, every such evacuation tending to lessen the animal powers. I have purposely avoided speaking of the fumes of tobacco, which always produce sickness or purging, according as they are applied. Whoever is appointed for the purpose of recovering drowned persons should have an assistant well acquainted with the methods intended to be made use of; that while the one is going on with the first and most simple methods, the other may be preparing what else may be proper, so that no time may be lost between the operations ; and this is the more necessary, as the first means recommended will, in all cases, assist the second ; and both together may often be attended with success, though each separately might have failed. A proper apparatus is also essentially necessary to the institution : a description of which I here annex. First, a pair of bellows, so contrived, with two separate cavities, that by expanding them, when applied to the nostrils or mouth of a patient, one cavity may be filled with the common air, and the other with air sucked out from the lungs ; and by shutting them again, the common air may be thrown into the lungs, and that which is sucked out of the lungs be discharged into the room. The pipe of these should be flexible, in length a foot or a foot and a half, and at least three eighths of an inch in width: as the artificial breathing may be continued by such means, while the other operations, except the application of the stimuli to the stomach, are going on ; which cannot conveniently be done if the nozzle of the bellows be introduced into the nose. The end next the nose should be double, and applied to both nostrils. Secondly, a syringe, with a hollow bougie, or flexible catheter, of sufficient length to go into the stomach, and convey any stimulating matter into it, without affecting the lungs. Thirdly, a small pair of bellows, such as are commonly used in throwing fumes of tobacco up the anus, by which stimulating fluids or even fumes may be thrown in. I shall conclude this account by proposing that all who are employed in this practice be particularly required to keep an accurate journal of the means used, and the degree of success attending them; whence we may be furnished with facts sufficient to enable us to draw conclusions, on which a certain practice may hereafter be established. J 17. AN ACCOUNT OF CERTAIN RECEPTACLES OF AIR IN BIRDS, WHICH COMMUNICATE WITH THE 9 LUNGS AND EUStACHIAN TUBE. Since the account of these receptacles was read before the Royal Society, in theyear 1774, I have, by the dissection of a number of birds, been able to make some additional observations relative to OF AIR-CELLS IN BIRDS. 195 the extent of the air-cells which communicate with the lungs in animals of this class. These latter observations were not, however, made in consequence of any regular design to investigate this subject further, as to have established the principle seemedaHl that was necessary; unless by general observations we could hope to throw more light on the final intention of this remarkable piece of mechanism. Before the period I have mentioned, the communication subsisting in birds, between the air-cells of the lungs and other cavities of the body, had not been clearly explained, nor even much attended to by anatomists or natural historians.* It is a singularity of structure peculiar to this tribe of animals; and on account of it canno!^ I imagine, be unacceptable to the public. It is not my present intention to enter into minute descriptions of all the particular communications of this sort discoverable in birds by dissection, but only to mention such general facts as may serve to introduce the subject into natural history, and lead to an inquiry into the purposes which this structure was intended to answer. With this view I shall endeavour to give some idea of the construction ofthe lungs, and ofthe air-receptacles in birds, occasionally remarking the circumstances in which these principally differ from what is seen in other animals. The mechanism ofthe lungs in birds, which renders them fit for

* [The continuation of the air-passages of the lungs into large membranous receptacles, situated in the abdominal cavity, was first discovered and described by Harvey (On Generation, 8vo., 1663, p. 7; Opera Omnia, 4to., 1766, p. 185). The abdominal air-cells ofthe ostrich are figured in Perault's Collection of Anatomical Memoirs of tho French Academicians. Borelli, in explaining the causes of the greater specific levity of birds, observes, " Hoc patet, quia ossa avium fistulosa, valde excavata et subtilia sunt, ad instar radicum pennarum scapulae, costae et brachia parum carnosa sunt pectus et abdomen amplas cavitates aere plenas habent; pennse tamen et plumae levissimae sunt." (De Motu Animalium, 4to., 1685, p. 231, prop. 194.) Borelli appears, however, to have believed both the quills of the feathers and the hollow bones to have contained only a light marrow. The discovery that the bones of birds contained air was first published in the year 1774,—in England in the Philosophical Transactions of that year, which contained Mr. Hunter's 'Account,' &c, read before the Royal Society, February 27, 1774; and in Holland in the Verhandeling van.Baiaafsche Genootschte, Rotterdam, 1774, in which Camper's discovery of the same structure was first published. Camper transmitted, in the year 1773, an account of his researches on the air-bones of birds to the French Academy, which was published in the Mtmoires de Mathematiques et Physique, 4to., in 1776. Whilst, therefore, we may be willing to admit that Camper's Memoir was founded on an independent discovery, we must also conclude that the mass of valuable observations on the air-receptacles of birds, communicated to the Royal Society some months before the first publication of Camper's discovery in the Dutch language, was equally original. The French translator of Carus's Comparative Anatomy, in a prefatory sketch ofthe History of the Science, introduces John Hunter to the reader's notice as follows : "Le premier, il (Camper) a fait remarquer que les os longs du squelette des Oiseaux sontcreuses de cavites dans lesquelles Fair a la facilite de s'introduire, parce qu'elles communiquent avec l'organe pulmonale, decouverte que Hunter eut l'impudeur de s'approprier quelques annees apres." (Jourdan's Carus, torn, i., p. xxxi.) Truly the ignorance of such an assertion can only be equalled by its impudence.), 196 HUNTER ON THE ANIMAL CECONOMY. conveying air to different parts ofthe body, consists principally in certain communications. It has been asserted that birds have no diaphragm ; but tnis opinion must have arisen either from a want of observation, or from too confined an idea of a diaphragm ; for there is a moderately strong, but thin and transparent membrane, covering the lower surface ofthe lungs, and adhering to them, that affords insertion to several thin muscles which arise from the inner surfaces ofthe ribs. The use of this part seems to be that of lessening the concavity of the lungs towards the abdomen at the time of inspiration, and thereby3assisting to dilate the air-cells, for which reason it is to be considered as answering one main purpose of a diaphragm. Besides this attachment of the lungs to the diaphragm, they are also connected to the ribs, and to the sides of the vertebra?.* Such adhesions are peculiar to this tribe of animals, and are of singular use, nay, in fact are absolutely necessary in lungs like those of birds, out of which it is intended the air should find a passage into other cavities. For if the lungs were loose in the cavity of the thorax, as is the case in many other animals, the cells of the lungs could not be expanded, either by the depression of the diaphragm, or the elevation of the ribs; since the air rushing in to fill up the vacuum produced in the cavity of the chest by these actions would take the straight road from the trachea through the passages, and of consequence would expand no part of the lungs which lay out of that line, whereby respiration would be totally prevented, and an effect produced exactly similar to what happens in other animals when the lungs are so much wounded as to allow a free exit to the air in that part.f The cells in the bodies of birds which receive air from the lungs are to be found both in the soft parts and in the bones, and have no communication with the cavity ofthe common cellular membrane. Some of these air-bags are placed in the larger cavities, as in the abdomen; and others are so lodged in the interstices of muscles, blood-vessels, and nerves, about the breast, axilla, &c, as at first to give the appearance ofthe common connecting membrane. Some communicate immediately with one another, and all may be said to have a communication by means of the lungs. They are of very diflerent sizes, as may best suit the particular circumstances ofthe parts in which they are placed. The bones which receive air are of two kinds; some, as the sternum, ribs, and vertebras, having their internal substance divided into innumerable cells; whilst others,as the os humeri and qsfemoris, are hollowed out into one large canal, with sometimes a few bony columns running across at its extremities. Bones of this kind may be distinguished from those that do not receive air by several marks: first, by their less specific gravity; secondly, by being less vascular than the others, and therefore whiter; thirdly,'by their containing * [See Harvey, on Generation, p. 6.] f [Ibid., p. 7.] OF AIR-CELLS IN BIRDS. 197 little or no oil, and consequently being more easily cleaned, and when cleaned, appearing much whiter than common bones; fourthly, by having no marrow, or even any bloody pulpy substance in their cells; fifthly, by not being in general so hard and firm as other bones ;* and sixthly, by the passage that allows the air to enter the bones, which can be easily perceived. In the recent bone we may readily discover holes or openings not filled with any soft substance, as blood-vessels or nerves; several of these holes are placed together, near that end of the bone which is next to the trunk of the bird, and are distinguishable by having their external edges rounded off, which is not the case with the holes through which either nerves or bloodvessels pass into the substance of the bone. When birds break any of the bones which contain air, the surrounding parts often become emphysematous. There are openings in the lungs by which air is transmitted to the other parts; and the membrane or diaphragm above-mentioned is perforated in several places with holes of a considerable size, which admit of a free communication between the cells of the lungs and the abdomen, a circumstance which has been frequently noticed. To each of these perforations is joined a distinct membranous bag, extremely thin and transparent, which bags being afterwards continued through the whole ofthe abdomen, and attached to the back and sides of that cavity, are kept firm in their proper situations, each receiving the air from their respective openings. There is no occasion to describe here all the bags, or their attachments, it being sufficient to have said that they extend over the whole abdomen. The lungs at the anterior part, contiguous to the sternum, have openings into certain membranous cells which lie upon the sides of the pericardium, and communicate with the cells of the sternum, At the superior part the lungs have a communication with the large cells of a loose network, through which the trachea, oesophagus. and great vessels pass as they are going to and from the heart. When these cells are distended with air, the size of that part where they lie is very considerably increased, and this enlargement is in general a mark of either the passion of anger or love. It is plainly seen in the turkey-cock, the pouting-pigeon, &c, and is very visible in the breast of a' goose when she cackles. These cells communicate with others in the axilla, under the large pectoral muscle, and in some birds are still further extended. In the pelican, for instance, the skin of the whole body, even to the tip of the wing, is united to the part underneath by means of these cells, which are equally formed; and when the skin is removed, the two separated surfaces appear as if honeycombed. When the cells are distended the skin is removed to a considerable distance, by which means the volume

* The bones of some birds are so soft that they can be squeezed together with the finger and thumb; the bones of the extremities, however, have very solid sides. 18* 198 HUNTER ON THE ANIMAL CECONOMY. is proportionally increased.* In most birds, I believe in all that fly, these axillary cells communicate with the cavity of the os humeri, by means of small openings in the hollow surface near the head of that bone; in some they are continued down the wing, communieating with the ulna and radius; in others they reach even as far as the pinions. The ostrich, however, is an exception. The posterior edge ofthe lungs (which lies on the sides of the spine, and projects backwards between the ribs,) communicates with the cells of the bodies of the vertebra), with those of the ribs, the canal of the medulla spinalis, and the cells of the sacrum and other bones ofthe pelvis ; from which parts the air finds a passage into the cavity ofthe thigh-bone. This takes place in the greatest number of birds; but in some the air is even continued part of the way down the thighs. This account agrees with what we generally find, though some birds have more, and some fewer of these communications; for, in the ostrich, no air gets into the os humeri, yet it enters into every other part, as before described, and in very large quantities. In the common fowl no air appears to enter any bone except the os humeri. The woodcock has no air-cells, either in the first bones of the wing or in the thigh-bones. On the other hand, in the pelican the air passes on to the ulna and radius, and into those bones which answer to the carpus and metacarpus of quadrupeds.! Thus the cells ofthe abdomen, those surrounding the pericardium, those situated at the lower and fore part of the neck and in the axilla, those in the cellular membrane under the pectoral muscles, as well as in that which unites the skin to the body, all communicate with the lungs, and are capable of being filled with air; and again, from them the cells of the sternum, ribs, vertebrae of the back and loins, bones ofthe pelvis, the humeri, the ulna and radius, with the pinions and thigh-bones, can in many birds be furnished with air. It is not by the lungs alone that air is conveyed into the bones of birds, for the cells of the diploe between the two plates of the skull, in some birds, receive a considerable quantity of air by the Eusta-

* [While inflating the air-cells of a gigantic crane (Ciconia Argalu), in which bird they are continued along the wing, beneath the skin, as in the pelican, the wings became extended as the air-cells were filled. This phenomenon suggested to me a secondary use of the air-cells, which appears not to have been noticed, viz., to render mechanical assistance to the muscles of the wings, both by keeping the wing extended during the long hovering flight peculiaAo this bird, and also by compressing and bracing the muscles, as is done by the fasciae ofthe extremities in man.] f [In the hornbill the air is also extended into the phalanges of the toes, and in short into every bone in the skeleton; whilst in the penguin, on the other hand, the air-cells are confined, as in reptiles, to the thoracic abdominal cavity, and not a single bone of the skeleton is permeated by the atmospheric fluid. These birds present the two extremes of the condition of the respiratory apparatus described by Hunter in the present paper.] OF AIR-CELLS IN BIRDS. 199 chian tube.* Of this the owl is a remarkable instance. The lower jaw of some kinds is likewise supplied with air, and often by the same canal.f Some authors have considered the diploe in the cranium of a bird as a continuation ofthe mammillary process, and looked upon it as a circumstance peculiar to singing birds, which is not really true. These facts, which had been formerly observed, led me in the year 1758 to make several experiments upon the breathing of birds, that might prove the free communication between the lungs and the before-mentioned parts. First, I made an opening into the belly of a cock, and having introduced a silver canula, tied up the trachea. I found that the animal breathed by this opening, and might have.lived; but by an inflammation in the bowels coming on, adhesions were produced, and the communication was cut off. I next cut the wing through the os humeri, in another fowl, and tying up the trachea, as in the cock, found that the air passed to and from the lungs by the canal in this bone. The same experiment was made with the os femoris of a young hawk, and was attended with a similar result. But* the passage of air through the divided parts, in both these experiments, especially in the last, was attended with more difficulty than in the former one ; it was indeed so great as to .render it impossible for ihe animal to live longer than evidently to prove that it breathed through the cut bone* I have made several preparations of these cells, by throwing into the trachea an injection, commonly called the corroding injection,

* The only thing in other animals similar to this communication in birds, of the cells of bones with the external air, is that which takes place in the internal ear of quadrupeds, by means ofthe Eustachian tube.a f When I wrote this account to send it to the Royal Society, I did not then know by what means thiis was done; for in that I said, "but by what means I do not know;" that is, I did not know whether it was conveyed by the trachea, where it passes along the neck, or the Eustachian tube. Professor Camper, when he did me the honour to call upon me, was so obliging as to take some pains to show me, in the lower jaw of the hawk, the hole where the air entered, which makes me suspect he did not understand what I had written. For after having given the marks by which such openings were particularly distinguished, it will hardly be supposed I could say that I did not know the hole where the air entered.b * [Camper, besides citing the mastoid processes as an analogous structure in the mammalia, also adduces the extensive sinuses containing air in the cranium of the elephant. The air-cavities of the diploe of the cranial bones in the porcupine are also remarkable for their extent.] b [In this note we have undesigned evidence that Hunter had never read the Memoir of Camper, or he would hardly have omitted to notice the error into which the Dutch anatomist falls with reference to the source whence the bones ofthe head derive their internal supply of air. Camper states that it is received by the meatus auditorii, believing that birds had no Eustachian tubes: "1'air enlredans le diploedu crane entierparlestrousaudiiifs; car les oiseauxn'ont point de frompes d'Eustacfoe comme les quadrupedes et les amphibies." (Mem. d» Mathem. et de Physique, torn. vii. 1776, p. 334.)] S>00 HUNTER ON THE ANIMAL CECONOMY. which first filled the air-cells of the lungs, then all the others, such as the cells in the abdomen, anterior and superior part ofthe chest axilla, os humeri, cells of the back-bone and thigh ; and the whole being afterwards put into spirit of sea-salt, and corroded, the cast of injection came out entire. The singularity of these communications in birds put me upon considering what might be their final intention. At first I supposed it might be intended to assist the act of flying, that being the circumstance which appears the most peculiar to birds; and it might be of service in that respect, I thought, by increasing the volume and strength with the same quantity of matter, wthout adding to the weight of the whole, which indeed would rather be diminished by the difference of specific gravity between the external and i,i. ternal air. This opinion was strengthened by discovering, that the feathers of birds contained also a considerable quantity of air, in the very part which requires the greatest strength, and by the analogy which is observed between this mechanism in birds and what is discoverable in most kinds of fishes ; for these last have air contained within their bodie?, which I believe is commonly supposed to lessen their specific gravity, although this does not appear so necessary in fishes, which move in a much heavier element than birds.*

* When we consider that the elevating and suspending apparatus is much smaller in fishes than in birds, we may reasonably conceive the air in them wa3 intended as a kind of equilibrium between the fish and water; and that progressive motion was the only thing wanted in the actions of fishes. Were we to reason upon general principles alone, we should suppose that those fishes who have the largest air-bags should have their muscles of a greater specific gravity, and those fishes that have none should have the lightest flesh ; therefore that the flesh of the salmon and cod, which have an air-bag, should be heavier than that ot the shark, which has none. But to know how far this, which appeared to be reasonable, was a fact, I made the following experiments: Experiment I. I took a portion of muscle ofthe shark, 'cod, and salmon, of the same weight in air; and first examined how far they occupied the same space, by immersing them in water, and observing the rise or fall of the water upon each ot them being separately immersed in it. The shark occupied the smallest space, the salmon a little more, and the cod the largest. ' Experiment II I then suspended the same three portions, upon a level, in a St,„te; f'lledK.\lth W*!,er *bout tW0 fee,; hi2h' and le* them all go at thesame instant to see which would fall through the: water in the shortest space of lime. The shark got to the bottom first, the salmon next, and the cod last Ja ilrfth!CHSSa7 ft*Tn-that'in b0th lhese exPeriments, the difference in bulk thl fan fL 1 M,.l e'r faUmg WaS Very ].Utl °'bu l' howe ver efficient to ascertain the tact for which the experiments were instituted . 0Md^rifii.e»i5!!S!UlaJ[ fl6Sh °f bi-ds W3S «Pecifi^"y Hghter than that of a quadruped, I repeated the above experiments upon a portion of a hind of a pigeon, and of a sheep; but could discover no vi«ikll J; it • \u .'.,.. Tt m!,,r k0 ot.c«r„„j .u ^'u uncover no visible difference in their weight. it diflLed thro^b th^r ,n vTT \W° situ*tionj of oil *" fishes: intone salmon herliT? T„ ,k' ?u 'f the b,°<,y had been ateePed « »> ™ in the salmon, herring, &c. In the other it is found in the liver, as in all of the rav kind, cod, &c, an in general those that have it in oneparhive none i he other; however, there are some, although I believe but flw, who have theVoU in form of what may be ca ed fat, viz in fl-.l™.* \n »k« ; ! wno nave meir on •srnrcTPnn Tho ii/D. in »k e :l ' . In the interstice of part3, as the sturgeon. The liver, in those of the ray krnd, is large, and extended through OF AIR-CELLS IN BIRDS. 201 But when I found that the ostrich (which is not intended to fly) was amply provided with these cells; and that the common fowl, and many others of that class, which are endowed with the faculty of flying, were less liberally supplied ; when I saw that even the woodcock, which flies and is supposed to be a bird of passage, was inferior in this respect to the ostrich, and that the bat differed not in structure from animals that do not fly ;* I was compelled, by so many contradictions to theory, to suppose that this singular mechanism might be intended for some other purpose. The next conjecture that offered was that these cells were to be considered as an appendage to the lungs; and to this I was led by the analogy observable between birds and amphibious animals. For although both in the bird and amphibious tribe, as the snake, viper, and many others, the lungs are continued down through the whole belly, in form of two bags,f and therefore appear to be larger than the lungs in any other animal, yet in all of them the quantity of surface exposed to the air is much less than in the quadruped; for the cells of the lungs in the bird are larger, and in the snake, &c. the uppef part only can perform the office of respiration with any degree of effect, the lower having comparatively but few air-vessels. The air must pass through this upper part before it gets to the lower in inspiration, and must also repass in expiration, so that the respiratory surface has more air applied to it than what the lungs of themselves could contain. It is not however to be supposed that the air can be made to pass to and fro in bones as in parts which admit of contraction and dilatation; the purpose answered by these bony cells must therefore be different, and perhaps they should be considered as reservoirs of air. J There is in fact a great similarity the belly; therefore it might be supposed to lighten the body, from oil being lighter than water or the flesh; but we have oil in the liver of the cod, and in the salmon and herring the oil is diffused through the whole: therefore I am afraid we are not yet acquainted with the full effect ofthe air-bladder in fishes. * [This is not absolutely true ; for it is a remarkable fact,—and one which gives additional probability to the hypothesis of Borelli as to the final intention ofthe air-cells of birds in diminishing the specific gravity for the facilitation of flight,—that in one genus of bats (Nycteris of modern naturalists) remarkable for their lofty and continued flight, air-cells are continued beneath the integument, which are inflated from the cheek-pouches. " The skin adheres to the body," says Bell, in his excellent article Cheiroptera (Cyclop, of Anatomy, p. 599), " only at certain points, where it is connected by means of a loose cellular membrane : it is therefore susceptible of being raised from the surface, on the back as well as on the under parts. These large spaces are filled with air at the will ofthe animal, by means of large cheek-pouches, which are pierced at the bottom, and thus communicate with the subcutaneous spaces just mentioned. When the animal, therefore, wishes to inflate its skin, it inspires, closes the nostrils, and then, contracting the cavity of the chest, the air is forced through the openings in the cheek-pouches under the skin, whence it is prevented from returning by means of a true sphincter, with which those openings are furnished, and by large valves on the neck and back. By this curious mechanism the bat has the power of so completely blowing up the spaces under the skin as to give the idea of a little balloon, furnished with wings, a head, and feet."] f [In most snakes the abdominal air-bag is single, but a rudiment of the second long exists.] X It is not to be supposed that the air in the cells in bird3 will be changed 202 HUNTER ON THE ANIMAL O3C0N0MY. between birds and that class of animals called amphibia; and although a bird and a snake are not the same in the construction of the respiratory organs, yet the circumstance ofthe air passing in both beyond the lungs, into the cavity of the abdomen, naturally leads us to suppose that a structure so similar is designed in each to answer a similar purpose. This analogy is still further supported by the lungs in both consisting of large cells.* Now in amphibious animals the use of such a conformation of the lungs is evident, as it is in consequence of this structure that they require to breathe less frequently than others ; and in this respect it may in birds have some connexion with flying, as that motion might easily be imagined to render frequency of respiration inconvenient, and a reservoir of air would therefore become singularly useful. Although we are not to consider this structure in birds to be an extension of lungs, yet I can easily conceive this accumulation of air to be of great use in respiration. For it was observed before respecting the amphibia, that the air in its passage to from these cells must certainly have a considerable effect upon the blood in the lungs, by allowing a much greater quantity of air to pass in a given time than if there was no such construction of parts ;f and this opinion will not appear to be ill founded, if we consider that both in the bird and in the viper the surface of the lungs is small in comparison to what it is in many other animals which have not this extension of cavity. It is also a corroborating circumstance, that in the fowl, the air might have passed by a much readier way than through the lungs into all the cells about the breast, neck, axilla, wings, &c, as these could have been filled from the lower end of the trachea, upon which many of

while flying; only accumulated and retained; not in the least influenced by either inspiration or expiration. It might be asked, Where is the stricture upon the air when flying, so as to keep the parts distended ] Is it upon the outlets from the lungs, or is it at the glottis, as in the quadruped 1 For we may observe that when an animal is using considerable exercise, it never either expands the lungs, nor makes a full expiration, giving the ribs and diaphragm as little extent of motion as possible, so that the body may be kept firm, which obliges it to breathe oftener; and as this quantity of air is not sufficient for the accelerated motion of the blood, the animal gets what is called out of breath, which is no more than the two not being proportioned; and when it rests, it breathes as quick and takes as long strokes as possible, to make up the loss. So that in exercise we probably breathe less air. * [The air-cells are smaller, and much mere numerous in the lungs of birds than in the corresponding anterior or true respiratory portion of the lungs of reptiles. The analogy which Hunter here mentions, as also that between the abdominal air-receptacles of birds and the air-bladders of fishes, to which he previously alludes, had not escaped the observation of Hervey, who says, " Quin etiara (quod tamen a nemine hactenus observatum memini) avium bronchia, siveaspene arteries fines, in abdomen perforantur, aeremque inspiratum intra cavitates illarum membranarum recondunt. Quemadmodum pisces, et serpentes intra amplas vesicas in abdomine positas eundern attrahunt et reservant; eoque facilius natare existimantur."—De Generatione Animalium, Ex. Ill ] f It may, perhaps, occur to some, that the whole of these communicating cells S« h~ CT!dered -aS fXtteTded lunP i bat I on hardly think that any air which gets beyond the ve» iculated lungs themselves is capable of affecting the blood of the animal, as the other cavities into which it enters, whether of thi soft partsor ofthe bones, appear to be very little vascular. P OF AIR-CELLS IN BIRDS. 203 them lie. But the air must now take a roundabout passage both in its way in and its way out, those openings being upon the exterior surface of the lungs. * We must not, however, give up the idea of such structure being of use in flying ; for I believe we may set it down as a general rule, that in the birds of longest and highest flight, as eagles, this diffusion of air is extended further than in the others. This opinion is strengthened by comparing the structure above described with the respiratory organs in the flying insects, which are composed of cells diffused through the whole body; these are extended even into the head and down the extremities; while there is no such appearance in the insects that do not fly, as the spider; but why the pelican should be so amply provided I cannot say, not knowing the natural history of that bird sufficiently to be able to judge of this point. Do they carry weights in the large fauces so great as to require such an increase of substance without increase of weight ? How far this construction of the respiratory organs may assist birds in singing deserves investigation, as the vast continuance of song, between the breathings, in a canary-bird would appear to arise from it. This is a subject, however, which I shall not at present enter upon.*

* [The objection offered by Hunter in the preceding note to the use ofthe aircells as accessory organs of" respiration, is weakened, if not removed, by the anatomical fact that the bronchia? open into them by such direct and wide apertures as to render it most probable that much ofthe air passes at once into the air-receptacles without having previously been'decomposed in the vesicles ofthe lungs. It may be concluded, therefore, that the respiratory function is heightened, in harmony with the increased energies ofthe circulating and locomotive powers in birds, by means of the extensive system of continuous air-receptacles above described, which operate both by effecting a change in the blood of the pulmonary circulation in the return of the air of the cells through the bronchial tubes, and also by the change which the blood undergoes in the capillaries of the systemic circulation, which are in contact with the air-receptacles. A second use of the air-receptacles in reference to the respiratory function arises out of the mechanical aid which they afford in the action of breathing. During inspiration the sternum of the bird is depressed or recedes from the spine, the angle between the vertebral and sternal ribs is made less acute, and the thoracic cavity proportionally enlarged ; the air then rushes into the lungs and into the thoracic air-receptacles, while those of the abdomen become flaccid; when the sternum is raised, or approximated towards the spine, part ofthe air is expelled from the lungs and thoracic cells by the trachea, and part driven into the thoracic receptacles, which are thus alternately enlarged and diminished with those of the thorax. Hence the lungs, notwithstanding thejr fixed condition, are subject to due compression through the medium of the contiguous airreceptacles, and are affected equally and regularly by every motion of the sternum and ribs. A third use, and one which Hunter inclines to admit, is that of rendering the whole body specifically lighter, in relation to the peculiar actions of flight. A diminution of specific gravity must necessarily follow the desiccation of the marrow and other fluids in those spaces which are occupied with the air-cells, and by the rarefaction ofthe contained air by the heat ofthe body. In harmony with this view are the facts, not only that the quantity of air admitted into the system is in proportion to the general powers of flight, but also that in birds where the skeleton is only partially permeated by air, this is especially distributed to 204 HUNTER ON THE ANIMAL CECONOMY. 18. A DESCRIPTION OF THE NERVES WHICH SUPPLY THE ORGAN OF SMELLING.

The nerves being in themselves perhaps the most difficult parts of an animal body to dissect, becomes a reason why we are still unacquainted with many of their minuter ramifications; yet if a knowledge of these, together with that of their origin, union, and reunion, is at all connected with their physiology, the more accurately they are investigated the more perfectly will the functions t>f the nerves be understood. I have no doubt, if their physiology was sufficiently known, that wTe should find the distribution and complication of nerves so immediately connected with their particular uses, as readily to explain many of those peculiarities for which it is now so difficult to account. What naturally leads to this opinion is, the origins and number of nerves being constantly the same, and particular nerves being invariably destined for particular parts, of which the fourth and sixth pair of nerves are remarkable instances. We may therefore reasonably conclude, that to every part is allotted its particular branch, and that however complicated the distribution may be, the complication is always regular. There are some nerves which have a peculiarity in their course, as the recurrent and chorda tympani; and others which are appropriated to particular sensations, as those which go to four of the organs of sense, seeing, hearing, smelling, and tasting; and some parts ofthe body having peculiar sensations (as the stomach and penis), we may, without impropriety, include the fifth, or sense of feeling. This general uniformity in course, connexion, and distribution, will lead us to suppose that there may be some other purpose to be answered than mere mechanical convenience; and many of the variations which have been described in the dissections of nerves, I believe to have arisen from the blunders ofthe anatomist, rather than from any irregularity in their number, mode of ramifying, course, distribution, or connexion* with each other. those members which are most employed in locomotion : thus it is admitted into the wing-bones of the owl, but not into the femur; while in the ostrich the air penetrates to the femur, but not the humerus or other bones ofthe wino\ I have already alluded to the secondary use which the air-cells may afford to some large and long-winged bird, which, like the Argala, or the Frigate Bird, hover with a sailing motion for a long-continued period in the upner regions ofthe air, by diminishing the necessity for muscular exertion by the tendency of the distended air-cells to maintain the wings outstretched. Of the same adventitious character is the use finally suggested by Hunter to the air-receptacles, of contributing to sustain the song of birds, and to impart to it tone and strength. It is no just objection to this function that the air-cells exist in birds which are not endowed with the mechanism and power of song, since it is not pretended that this is the primary or exclusive office of the air-cells. The latest writer on the pneumatic.ty of birds M Jacquemin, has indeed reproduced this suggestion of Hunter's as a novel idea.] bo hrL1!!? Uv t0-bf undersJood Ido ^t mean lateral connexion, such as two branches uniting into one chord and then dividing; or a branch going to a part, THE NERVES OF THE ORGAN OF SMELLING. 205

We observe no such uniformity in vessels carrying fluids, but find particular purposes answered by varying their origin and distribution: the pulmonary artery answers a very different purpose in the circulation of the blood from that of the aorta ; yet both arise from the same source, the heart. The course ofthe arteries is such as will convey the blood most conveniently, and therefore not necessarily uniform, it not being very material by what channel, provided the blood is conveyed to the part; though in particular instances certain purposes may be answered by a peculiarity in origin and distribution, as happens in the testicle of quadrupeds. This observation respecting arteries is likewise applicable to veins, and still more to the absorbent vessels; in which last, regularity is even less essential than in the .veins. Whoever, therefore, discovers a new artery, vein, or lymphatic, adds little to the stock of physiological knowledge; but he who discovers a new nerve, or furnishes a more accurate description of the distribution of those already known, affords us information in those points which are most likely to lead to an accurate knowledge of the nervous system; for if we consider how various are the origins of the nerves, although all arise from the brain, and how different the circumstances attending them, we must suppose a variety of uses to arise out of every peculiarity of structure.* Indeed, if we reflect on the actions arising immediately from the will and affections of the mind, we must see that the origin, connexion, and distribution of the nerves ought to be exact, as there

either single or double, for still it is the same nerve; or whether a branch unites with another a little sooner or a little later, for still it is the same branch. Such effects may arise more from a variety in the shape of the bodies they belong to, than any variety in the nerves themselves.a * [With reference to anatomical researches on the nervous system, Sir Charles Bell has observed : " Whilst the nerves are supposed to proceed from one great centre, to have the same structure and functions, and to be all sensible, and all of them to carry what has been vaguely called nervous power, these discoveries of new nerves and ganglia are worse than useless; they increase the difficulty, and repel inquiry."—Exposition of the Natural System ofthe Nerves of the Human Body, 1824, p. 70. The different views entertained by Hunter on this subject doubtless arose from his belief that a variety of uses arose out of the various origins and other peculiarities of structure of the nerves. Hence he was led to trace the different nerves which are distributed to a single organ to their different origins, and to infer that the organ thereby received different sensitive endowments. It is this principle, in a more extended application from the nerves to their component filaments, so far as they have different origins, which forms the basis of the present improved doctrine ofthe nervous system. " The key to the natural system ofthe nerves," says Bell, " will be found in the simple proposition, that each filament or track of nervous matter has its peculiar endowment, independently ofthe others which are bound up along with it, and that it continues to have the same endowment throughout its whole length."—Ibid.] a [See the observations of Swan on the exceptions which occur in the uniformity ofthe anatomical conditions ofthe nervous system, in his excellent 'Demonstration ofthe Nerves ofthe Human Body,' pp. 29, 30, 31.] 19 206 HUNTER ON THE ANIMAL ECONOMY. are parts whose actions immediately depend upon such circumstances. The brain may be considered as having an intelligence with the body ; but no such intercourse subsists between the different parts of the body and the heart. In the summer of 1754, being much employed in dissecting the nerves passing out of the skull, I was, of course, led to trace many of their connexions with those from the medulla spinalis ; and was assisted by Dr. Smith, then pursuing his studies in London.* The better to "trace these nerves through the foramina of the skul, I steeped the head in a weakened acid of sea-salt till the bones were rendered soft, and that the parts might be as firm as possible, and at the same time free from any tendency to putrefaction (it being summer), the acid was not diluted with water, but with spirit. When the bones were rendered soft, pursuing my intention, I dissected the first pair of nerves, and discovered their distribution; and having made a preparation of the parts in which they were found, I immediately had drawings made from them, with a view to have presented the account to the Royal Society ; but other pursuits prevented it.f Engravings were afterwards made from these drawings, and the preparation was repeatedly shown by Dr. Hunter, in his courses of anatomy, who, at the same time, pointed out that alteration in the mode of reasoning upon those nerves which would naturally arise from this discovery. In this dissection I found several nerves, principally from the fifth pair, going to and lost upon the membrane of the nose ; but suppose that those have nothing to do with the sense of smelling, it being more than probable that what may be.called organs of sense have particular nerves, whose mode of action is different from that of nerves producing common sensation, and also different from one another, and that the nerves on which the peculiar functions of each ofthe organs of sense depend, are not supplied from different parts of the brain. The organjof sight has its peculiar nerve ; so has that of hearing; and probably that of smelling likewise; and, on the same principle, we may sup-

* Dr. Smith was afterwards teacher in chemistry and anatomy in the university of Oxford ; is now Savilian professor of geometry, and lecturer in physiology. This account of the first pair of nerves, as also of the branches of the fifth, is taken from the original description written by him, and taken from my dissection when I was tracing them. f Dr. Scarpa, professor of anatomy at Pavia, while in London in 1782, acquainted me that he had dissected the ramifications of the olfactory nerves, and that on his return to Italy he meant to publish an account of them. At this time I showed him my drawings and engravings. I have lately been informed that he has published his account, but have not met with it: I have, however, seen one of his engravings, which was executed in London, and is very elegant. It only shows those on the septum narium, whose minuteness is rather carried further than the power of dissection, and the ramifications are more regular than we find them in Nature.a a [See Scarpa, Anatomies Disquisitiones de Auditu et Olfactu, fob 1789, and Anatomicarum Annotatwnum, Liber secundus De Organo olfactus prsecipuo, deque Nervis nasahbus intenoribus e Pari quinto Nervorum cerebri, 4to 1782 ] THE NERVES OF THE ORGAN OF SMELLING. 207 pose the organ of taste to have a peculiar nerve. Although these organs of sense may likewise have nerves from different parts of the brain, yet it is most probable such nerves are only for the common sensations of the part, and other purposes answered by nejves. Thus we find nerves from different origins going to the parts composing the organ of sight, which are not at all concerned in the immediate act of vision; it is also probable, although not so demonstrable, that the parts composing the ear have nerves belonging to them simply as a part of the body, and not as the organ of a particular sense: and if we carry this analogy to the nose, we shall find a nerve, which we may call the peculiar nerve of that sense : and the other nerves of this part, derived from other origins, only conveying common sensation, and we may suppose only intended for the common actions of the part. This mode of reasoning is equally applicable to the organ of taste; and if the opinion of peculiar nerves going to particular organs of sense be well founded, then the reason is evident why the nose, as a part of our body, should have nerves in common with other parts, besides its peculiar nerves ; and, as the membrane of the nose is of considerable extent, and has a great deal of common sensation, we may suppose the nerves sent to this part for that purpose will not be few in number. It is upon this principle the fifth pair of nerves may be supposed to supply the eye and nose in common with other parts ;* and upon the same principle, it is more than probable, that every nerve so affected as to communicate sensation, in whatever part of the nerve the impression is made, always gives the same sensation as if affected at the common seat of the sensation of that particular nerve.f

* [Since the period when Hunter wrote this remarkable paper, in which the principle of different nerves having particular functions in relation to differences of origin and other anatomical conditions is so distinctly enuntiated, the attention of physiologists has been more especially called to the fact of the organs of sense being supplied by nerves from different sources, for the purpose of different endowments, by the experiments of Magendie. He divided the fifth pair of nerves within the cranium, and thus contributed to define more exactly than had before been done the importance of common sensation to the safety of some of the organs of sense, as the eye, and also the share which touch bears in the impressions received by the organs of special sense, as in that of smell. Physiological science does not perhaps afford a more striking example of the inferiority of mere experimental inquiry to that which is based on extensive anatomical induction, than the singular conclusions at which Magendie arrived after performing the experiment above alluded to. There are few physiologists, however, who do not adopt the conclusions of Hunter, that the organs of sense receive their endowments of ordinary sensation from the fifth pair, which is common to each, in preference to the well-known view originally adopted by Magendie. (See Journal de Pysiologie Exper., vol. iv., 169. " Le nerf olfactif est-il Porgane de l'odorat ?")] f I knew a gentleman who had the nerves which go to the glans penis completely destroyed by mortification, almost as high as the union ofthe penis with the pubes; and at the edge of the old skin, at the root of the penis, where the nerves terminated, was the peculiar sensation ofthe glans penis ; and the sensation ofthe glans itself was now only common sensation; therefore the glans has 208 HUNTER ON THE ANIMAL O3C0NOMY. The first pair of nerves arriving at the part of its destination as soon as it escapes from the skull, and immediately ramifying, has rendered its distribution more obscure than that of the others, whose course to the part to which they are allotted is visible and to be traced. As the body of the nerve, while within the skull, is pulpy and composed of the brain itself, it easily breaks off at the very division and exit of the small branches; it therefore becomes impossible to trace them, as we usually do other nerves; and they have by most physiologists been considered as never forming chords, but going on in their pulpy form to be distributed on the membrane of the nose, in a mode somewhat similar to that of the optic nerve, and to what is commonly supposed to'take place with respect to the portio mollis of the seventh pair. Winslow has suggested an idea that the first pair forms chords; but it is only as an assertion, and not having described them, that alone was not sufficient to alter the former mode of reasoning. Haller, who is to be considered as the latest anatomist and physiologist, who has published on the subject, on whom we can depend says, that" The first pair of nerves makes its way into the nose covered by the pia mater only, very little altered from what it was when within the cavity of the skull."* This shows that Haller retained the old idea concerning these nerves; but we shall find that they become firm chords immediately upon piercing the dura mater and cribriform plate of the ethmoid bone. The first pair, while within the skull, differs in some respects from all other nerves : firstly, it seems to be made up of a cortical and medullary substance ; while the others appear to consist of medullary alone ; and secondly, it is different, in that it does not seem to be composed of fasciculi, and has but one covering from the pia mater investing the whole nerve, whereas other nerves appear to have a covering round each fasciculus; and this is probably the reason why the first pair is weaker while within the skull than the others. Its form is somewhat triangular, having three edges, from lying in a groove made by two convolutions of the brain. The course is forwards, a little upwards and inwards, and where it lies upon the cribriform plate of the ethmoid bone becomes somewhat larger, and divides into a great many branches, like so many roots, answering to the number of holes in that plate, except one left for a branch ofthe fifth pair; but these divisions we cannot see, they being covered by the body of the nerve, which cannot be raised without breaking off the small branches at their origin. As the

probably different nerves, and those for common sensation may come through the body of the penis to the glans. A Serjeant of marines, who had lost the glans and the greater part of the body otthe penis, upon being asked if he ever felt those sensations which are peculiar to the glans, declared, that upon rubbing the end of the stump, it gave him exactly the sensation which friction upon the glans produced, and was followed by an emission of the semen. ' * Elementa Physiologiae, vol. v., p. 151. OF SOME BRANCHES OF THE FIFTH PAIR OF NERVES. 209

branches ofthe nerve pass through this bone, they seem to take processes from the dura mater along with them, then becoming firm chords, similar to other nerves. These branches, after they have got through the bone, form themselves into two planes or divisions, one passing on the septum, the other on the turbinated bones. Those ofthe septum narium, in their passage to the nose, are first continued a little way down, in bony canals of the perpendicular lamella of the ethmoid bone, which holes become small grooves in that bone ; and those on the opposite side being more numerous and smaller, pass down through small holes that are on the inside plate ofthe ethmoid bone, which holes are likewise continued into grooves, for a little way, upon that plate. When the branches get upon the membrane of the nose, they subdivide into a great many smaller ones, which are somewhat flattened, and are only to be seen on that side ofthe membrane that adheres to the bones, not being visible at all on the other; so that the dissection of these nerves is no more than separating the membrane and bone from each other. They can hardly be dissected all round ; and the further they are traced upon the membrane the fainter they become, and growing smaller they sink deeper and deeper into the membrane to get on its outer surface, where we must suppose they terminate. Those upon the septum pass down a little radiated, and the branches, especially at the upper part, or at their first setting out, unite with one another. Those on the side next the antrum, when they have reached the membrane of the nose, in their course to the superior turbinated bone, form a very considerable network or plexus; and when they reach that bone, do not all go round its convex curvated pendulous edge to the concave side, but some passing through its substance get immediately upon it, which is the reason why we find so many holes in that bone. It is difficult to trace them further; but we have reason to suppose that they go through the inferior turbinated bone in the same manner, since we find similar holes. 19. A DESCRIPTION OF SOME BRANCHES OF THE FIFTH PAIR OF NERVES.

In tracing the course of the olfactory nerves, I also discovered several branches of the fifth pair not commonly known, particularly two that were supposed to go to the membrane of the nose for the sense of smelling, but which only pass through that organ to their place of destination. The first is a small nerve from the first branch of the fifth pair; or, according to Winslow, the nervus ophthalmicus Willisii, which small nerve is called by Winslow the nasal. This branch, after having passed out of the skull into the orbit, reenters the cranium through the foramen orbitariumanterius, and gets 210 HUNTER ON THE ANIMAL CECONOMY. on the cribriform plate of the ethmoid bone; frpm thence it passes down through one ofthe anterior holes ofthe cribriform plate, and after having continued its course in a groove on the nasal process of the frontal bone, runs forward and downward in a similar groove on the inside of the os nasi; from thence getting on the outside of the cavity of the nose, it runs along the cartilaginous part of the ala, and near the extremity of the nose mounts up upon the tip of the ala, and then dipping down between the two alse, is lost on the anterior extremity of the cartilaginous septum. In it's course it sends several small filaments into the alse. The second is a branch of the superior maxillary nerve; for that nerve, having passed through the .foramen rotundum, divides and sends off several branches, one of which passing backwards and inwards, through the foramen commune, between the orbitar process of the palate, and the root of the ala of the sphenoid bone, gives a branch which gets into a fissure that seems to separate the root of the ala from the body of the sphenoid bone, where that bone makes the roof of the nose. This branch then passes along the under surface of the body of the sphenoid bone, in its way to the septum narium, and getting upon that part, passes along between its membranes and the bone: its course is downwards, and forwards towards the foramen incisivum, through which it passes and is lost in the gum behind the first dentes incisores, and on the membrane of the roof of the mouth at that part. There is another branch of the superior maxillary nerve, which comes off from a large branch that is going down to the mouth, uvula, &c, and this branch, with its division into two, has been described by Professor Meckel, of Berlin; but after tracing one of these into the portio dura, he pursued the search no further. This branch of the superior maxillary nerve passes back through the foramen pterygoideum, accompanies the carotid artery as it passes across the posterior edge of the foramen, and there divides into two branches; one of which passes down along with the carotid artery, through the basis of the skull, and proceeding in a direction contrary to the course of the artery, in contact with that branch of the cervical ganglion that passes up with the carotid artery to join the sixth pair, then joins the first cervical ganglion. The other branch decussates that artery on its upper surface, and getting upon the anterior side of the petrous portion of the temporal bone/enters a small hole near the bottom of that large one which affords a passage to the seventh pair of nerves, joining the portio dura just where that nerve, making its first turn, passes along with it through what is called the aqueduct. This nerve, composed of portio dura, and the branch of the fifth pair, sends off, in the adult, the chorda tympani before its exit from the skull; and in the fcetus immediately \ n j teFminatlon of the branch, called chorda tympani, I shall not describe; yet I am almost certain it is not a branch ofthe seventh pair of nerves, but the last-descibed branch from the fifth pair; for I think I have been able to separate this branch from the CROONIAN LECTURES ON MUSCULAR MOTION. 211 portio dura, and have found it lead to the chorda tympani; perhaps it is continued into it; but this is a point very difficult to determine, as the portio dura is a compact nerve, and not so fasciculated as some others are. However this may be, it is very reasonable to suppose that the chorda tympani is a branch of the fifth pair, as it goes to join another branch arising from the same trunk.* 20. CROONIAN LECTURE ON MUSCULAR MOTION, NO. I.

[Read before the Royal Society, by Mr. John Hunter, F.R.S.f]

A self-moving power is such a phenomenon as must call up the attention of the thinking mind (while ignorant of the cause); and when that very mind is connected with this power it becomes still more interested. This power of motion was first discovered to be inherent in parts of an animal body of a certain construction, called muscles.J This construction appeared to be a composition of fibres, which were called muscular: and motion was supposed to be produced by these contracting in length, and all the varieties of motion in an animal

* [This is a point which it is undoubtedly very difficult to decide by dissection of the parts in the human body. Cloquet, Hirzel, and Majendie describe the chorda tympani according to the supposition of Hunter. In the horse and calf, however, where the portio dura is less dense in its structure, the Vidian branch ofthe fifth may be distinctly seen crossing that nerve after penetrating its sheath, and separating into many filaments, with which filaments of the seventh nerve are blended, and a ganglion formed by the superaddition of gray matter; the chorda tympani is here continued partly from this ganglion, partly from the seventh or portio dura.] f [In Home's Account of the Life of John Hunter, prefixed to the treatise 'On the Blood, Inflammation, and Gunshot Wounds,'1794, p. xxviii., is the following passage: " Besides the papers which he presented to that learned body (the Royal Society), he (Mr. Hunter) read six Croonian Lectures upon the subject of muscular action, for the years 1776, 1777, 1779, 1780, 1781, 1782. In these Lectures he collected all his observations upon Muscles respecting their powers and effects, and the stimuli by which they are affected ; and to these he added comparative observations upon the moving powers of Plants. These Lectures were not published in the Philosophical Transactions ; for they were withdrawn as soon as read, not being considered by the author as complete dissertations, but rather as materials for some future publication."] X [Both Aristotle and Hippocrates were ignorant of the function of the muscular fibre: the important discovery that the animal motions were performed by the muscles is attributed to Lycus of Macedon, who wrote a voluminous work on Myology. It is certain that the use of the muscles was known to Herophilus, since he is quoted by Galen as having spoken of the happy disposition of the muscles for the movement of the limbs. To Herophilus belongs the honour of having first discovered in the nerves the organs of sensation and of voluntary motion.] 212 HUNTER ON THE ANIMAL CECONOMY. the most complicated, to be the result of the manner in which these fibres were disposed. It is no wonder, then, that the mode in which a muscular fibre produces motion has been esteemed an inquiry not unworthy the attention of the greatest philosophers, and has almost universally been one of the principal researches of the physiologist; especially when we consider that the substance, called muscular, alone constitutes the largest part of most animals ; and indeed many are wholly composed of it. The inquiries into the nature of self-motion have been principally confined to animals ; most probably from the power in them being more conspicuous, which almost prevented its being taken notice of in any other substance whatever. Inquiries into nature have, however, become less confined, and experiments and observations have induced men to leave the beaten track of others, and take their observations from nature herself; by which means a self-moving power has been observed and universally allowed in vegetables. And this principle, upon investigation, appears now to be as much a property in vegetables as in animals; and in such cases where the functions and uses are the same in both, it is perhaps as considerable in vegetables as animals. But where they are dissimilar in their actions, and the uses arising out of these actions are also different, it is reasonable to suppose the quantity of action will vary; and such difference must frequently occur in both animals and vegetables. In animals a considerable part of this motion is called muscular; in vegetables it has not yet got a name. The immediate cause of motion in all vegetables is most probably the same, and it is probably the same in all animals; but how far they are the same in both classes has not yet been determined. But I think it will appear, in the investigation of this subject, that vegetables and animals have actions evidently common to both, and that the causes of these actions are apparently the same in both: and most probably there is not an action in the vegetable which does not correspond or belong to the animal, although the mode of action in the parts may not be the same, or muscular, in both. There appear, however, to be actions in animals which are peculiar to them ; these make them more complicated, and in them another stimulus to action is superadded, evidently for that purpose.*

* [The actions here alluded to are the voluntary, which are consequent upon an act of sensation, and are the result of a determination or stimulus derived from the brain. The action in the muscle produced by this stimulus is, however, essentially the same as is produced by mechanical or chemical stimuli applied to the muscle out of the body, or as takes place in the muscle involuntarily as in sleep, or when an animal is stimulated while in a state of hybernation, or immediately after decapitation. Instead therefore of saying that animals have actions of the moving powers peculiar to themselves, it is more correct to express, with reference to the voluntary actions, that they have parts superadded, for the purpose of exciting the actions of the moving powers, which the vegetable has not, viz., the nerves. It is true that the actions of the moving powers of an animal, whether automatic CROONIAN LECTURES ON MUSCULAR MOTION. 213

All actions may be considered of two kinds, immediate and secondary. The first is an action ofthe part itself, having no relation to anything else ; as action in a muscle, or elasticity in a spring. The second may be divided into two kinds,—first, where this action has an effect upon some other part, or moves it, which is the ultimate effect, as the heart moving the blood by contracting,— secondly, where the action is applied to some other body adapted for a particular motion, which is to produce the ultimate effect, such as the muscles of a joint. We may in general observe, from what we know of motion or action in ma'tter, that it is always preceded by something which we call the cause; and that the immediate cause is an irresistible impulse to action, which action becomes the effect. A body endowed whh the power of self-motion is under the same influence of impulse as matter in general: it cannot move without an intermediate cause for its motion. Self-motion may be of three kinds in the more perfect animals. The first is where the motion is excited by a cause from within the animal itself, and is employed in the oeconomical 6perations and functions of the machine, and with the materials the machine is already in possession of, which are only made use of in the growth of parts, secretion of fluids, &c. The second is where motion is excited from an internal cause, and is employed in particular functions and operations, but where such materials used are out of the body; as in those excited in consequence of hunger and thirst, the passion between the sexes, &c. The third is where motion is excited by external stimuli, and where whole parts are put in motion : as where the sight or voice of a person excites one to approach him; the application of a medicine which excites vomiting, &c. We can have no other idea of these motions in animals, but that they are muscular: and as the two first of these actions exist in vegetables, it is natural to suppose that there is a similarity in the cause which produces the same final intention, although the same mode of action or a similar power is not made use of to produce it. These immediate causes of action in an animal are called stimuli, and the capability in parts for action is termed irritability; but such a definition is too confined for the numerous actions excited in an animal body. The word stimulus is pretty well determined in its signification; it is an incitement to an action of a proper or salutary nature : but the calling a part capable of being stimulated an irritable part, weakens the idea of the stimulus being the cause of the action ; and indeed the expression of a part being irritated conveys a different meaning from what would be annexed to the effect produced by a

or voluntary, are different from those which produce the motions of parts in vegetables, as explained in the notes, pp. 216, 222 ; but the observations in the text refer only to the voluntary actions.] 214 HUNTER ON THE ANIMAL CECONOMY.

stimulus. I would therefore define a ' stimulus' to be the cause of an increased natural action ; and an ' irritation' to be the cause of an unnatural, disagreeable, or diseased action. Vegetables as well as animals have their motions produced by these causes, and are subject to the very same laws. A stimulus or excitement to actions of a salutary or proper kind is simple, and depends on the original mode of action, or the original laws of the vital ceconomy, and the action only changes in some degree as the properties of the matter which stimulates changes. An irritation or excitement to morbid action is according to the susceptibility of the body or part which is to be excited to action, and alters according to the power of the irritating matter, combined with the various susceptibilities of different animals and parts for irritation; for different animals and parts have different modes and powers of receiving the same power of irritation. In the more perfect animals we have the senses, or parts so constructed as to be impressed by the various properties of matter, and, as it were, adapted to these properties alone. These are connected together by the brain, or common sensorium, which is common to the whole of the sensitive powers: to and from the brain pass the nerves, or conductors of sensation and voluntary stimulus. But as animals become more and more imperfect, the senses, or parts constructed so as to be impressed by the properties of matter, become fewer, and the common sensorium less perfect. There appear to be animals entirely deprived of these parts or senses, and consequently having neither brain nor nerves.* These senses give us intelligence of the various properties of matter, from whence we derive our acquired actions, and have been naturally led to suppose that there were no other causes of action in an animal body. The eye gives us at once the shape or limits, and the various effects of the reflection of light from bodies at a distance; the first of which could not be sufficiently effected by the sense of touch, and the second we could not have had the least idea of, the common powers of touch not being sufficiently acute. The ear is adapted to receive the vibrations of air, giving us intelligence of bodies at a distance. The nose is adapted for smelling, giving us the odorous properties of the matter of which bodies at a distance are composed. ,.Jhe t0"gue 1S adapted to tasting, giving us a property in matter different from any discovered by the sense of touch. The sense of touch gives us a vast variety of information respecting the form, construction, density, &c, of bodies. In giving

* [Mr. Hunter nevertheless appears subsequently to have believed that the ^Z m^ri^^fl10'^6-^ 0f,ra0dern "«««»■*. had something similar to the materials ofthe brain diffused through the body; and that eviry other principle or elementary tissue, as the muscular fibre, was diffused through the

Swtessr contractile and stimuiab,e'as in the fresh-water CROONIAN LECTURES ON MUSCULAR MOTION. 215

us form and construction it is somewhat similar to the eye ; but it is obliged to run over the whole for this intelligence, whereas the eye takes in a larger scope of this intelligence at once. However, even the eye is obliged to do the same thing where the object is too large, or where it is examining minutely. None of these senses are affected by a stimulus or an irritant, although either the one or the other may be carried so far as to produce sensation. This, however, is not a necessary effect, unless the stimulus or irritant is the immediate object of sensation; as the stimulus of ligfct to the eye, or the irritation of too much light to the eye. These organs of sense are parts constructed for sensation, and those animals that are endowed with all of them must be the most sensible; and those that are entirely deprived of them must be wholly insensible to every impression arising from the different modifications or external influence of matter. The animals which receive no intelligence from external objects have their actions arising out of immediate stimuli and irritants,* and their consequent sympathies, which last extend to the action beyond the part of impression. The perfect animals in some instances seem also to be under some general power or external influence, not referrible to any one sense or all of them taken together: it is a general observation that many animals go into shelter before a storm comes on, and before any of the particular senses can be effected. Many people are weather-wise, as it is vulgarly called, and, like the brutes, are sometimes previously apprised of the ensuing change. Many sleep soundest in a storm, especially when attended with thunder. The natural salutary actions, arising from stimuli, take place both in animals and vegetables, and may be divided into three kinds. The first kind of action, or self-motion, is employed simply in the ceconomical operations, by which means the immediate functions are carried on, and the necessary operations performed, with the materials the animal or vegetable is in possession of, such as growth, support, secretion, &c. The blood is disposed of by the actions of the vessels, according to their specific stimulus, producing all the above effects. The juices of a plant are disposed of according to the different actions of the sap-vessels, arising also from their specific stimulus, which is different from that of blood-vessels, but equally produces growth: but a vine will grow twenty feet in one summer, while a whale probably does not grow so much in as many years.f The second kind of action is in pursuit of external influence, and arises from a compound of internal and external stimulus; it is ex-

• [*. e. Of stimuli which do not produce action through the medium of the brain.] t [The insensible organic contractility of Bichat corresponds with the kind of action which Hunter here defines.] 216 HUNTER ON THE ANIMAL CECONOMY. cited by the state ofthe animal or vegetable, which gives the stimulus of want, and, being completed by external stimulus, procures the proper supplies of nourishment. It produces motions of whole parts : thus we see the Hedysarum gyrans moving its lesser foliola. This is an action apparently similar to breathing in animals, though perhaps it does not answer the same purpose; yet there is an alternate motion in both. The cirriferous plants, or those bearing tendrils or claspers, requiring to be supported by other bodies, as the passion-flower, briony, vine, &c, stretch out their tendrils as it were at random, moving them slowly in various directions. They are to lay hold of any substance that may be within their reach that can support them, and when they come in contact with a body on that side where their power of motion is greatest they begin to bend in that direction, grasp it, and continue turning round it. We see motions ofthe same kind in the stems of the Planta volubihs; some of these turn to the left, as the Lonicera, Humulus, &c; some to the right, as the Clitoria, Convolvulus, &c. They are directed in this course by a lateral inclination, which takes place only on one side, they having little or no power of action on the other. Those which have one mode of action pursue that principally; but if prevented from doing it, their action then varies. In the vine and other plants the action ofthe tendrils is in-different directions; and they may be seen at one time stretched out on one side of the stem, and in twenty-four hours' time on the opposite side ; and some time after in the direction of the stem itself, or in the very contrary direction. These actions arise equally from stimulus; it requires, however, different powers of action, arising from such stimulus, to produce these effects in different plants.* The random action of the polypus is of the same kind as those of plants. It elongates itself and throws out its tentacula, moving them in various directions to catch food; the use of this action to the animal, however, is immediate, and therefore quicker than those above described.!

* [In the plants ofthe genus Cuscuta the tendrils will only twine around other living plants, which shows that the phenomena of climbing plants are not explicable simply by supposing that the inclination of the extremities of the tendrils or stems towards one side is a necessarily inherent law of their growth, but that it is, as Hunter regards it, an action dependent on stimulus, which, in the case of the Cuscuta, would seem to be a species of organic affinity.] f [In comparing the motions of a polype with those of a plant, the following difference must be borne in mind : the motions of a plant, like those of the parts of an animal after their communication with the brain has been cut off, are invariably the result of external stimulus ; they follow, as it were mechanically, some appreciable change in the surrounding external circumstances or influences, —it may be alteration of temperature, difference of light, the application of a chemical or mechanical stimulus; or, in an animal, loss of blood, &c. But whoever observes the actions of a living polype will see that although, for the most part, they may be traced to an external cause or stimulus, yet that one or more of the tentacula are occasionally extended or retracted without the slightest appreciable change in any of the external circumstances under which the animal exists. These motions evidently resultfrom an internal impulse, and I would refer them to the presence, in the polype, of an organic element,—the nervous matter,—which CROONIAN LECTURES ON MUSCULAR MOTION. 217

The third kind of motion is from external stimulus, and consists principally of the motion of whole parts, which is not inconsiderable in vegetables, as in the Dioncea muscipula and Mimosa pudica is very evident; for the first, upon being touched, closes up, and as it were confines the stimulating cause; the second bends its leaves, from external stimulus. This kind of motion is very strongly illustrated in the Tragopogon, Calendula pluvialis, and many other plants, which shut up their flowers either towards night or when rain comes on ; and in others of diflerent genera which open in the evening, and shut up on the approach of the sun, as different species ofthe Convolvulus, Mirabilis, &c.; and in almost the whole class Diadelphia, which chiefly consists of the winged-leaved plants, which shut up their foliola towards night, not expanding them till morning, which is called by Linnasus the sleep of plants; and in the motion of the footstalk of the leaf of an inverted plant, which twists so as to bring the surface of the leaf naturally uppermost to its natural position, which is remarkable in the vine, where there is evidently an apparatus for motion, although not a joint. These actions are similar to what arise in many animals from external stimulus, more especially those not endowed with sensation, and also to the actions of many parts of animals which do not appear to be directed or stimulated by the brain and nerves; as the actions of a polypus, which has no brain, and the peristaltic motion -ofthe intestines in the more perfect animals, which does not arise from the stimulus of the brain and nerves.*

is wanting in the vegetable; even in that plant, which, from the energy of its excitability, has been erroneously called sensitive. There is also an essential difference in the nature of the motion itself of the Mimosa and Hydra. If we touch one of the feelers of the polype it recedes from the irritant by a true contraction of the part within itself; which contraction appears to result from the injury experienced by that pait of the nervous system which is disseminated through the feeler touched. In the case of the Sensitive plant there is nothing like that contraction of the part touched, but only an articular plication of the neighbouring part without any of the dimensions of the irritated leaf being altered.] * [The more just comparison of the motions of plants adduced in the text would be with those automatic actions of whole parts which take place in animals, but which resultfrom the power possessed by the central axis of the nervous system, or any part of it, to transmit the action of an excitable nervous fibril to the exciting one with which that central axis or part brings it into communication: I apply the terms excitable and exciting to the nervous fibres with reference to their intermediate relation, as to the muscular fibre and the external stimulus to its contraction. The excitable fibres are those usually termed sensitive; the exciting fibres those usually termed motive. When the communication between the excitable nervous fibre and the brain is entire or uninterrupted, the latter may take cognizance of the excitement and sensation be produced. When the exciting nervous fibres of muscular motion are in connection with the brain, the will, through the brain, may excite them to action, and this act of the brain may be felt. The essential character, therefore, of the actions of the brain, whether as a recipient or transmitter of impressions, is consciousness of the action. But this property of consciousness is not possessed by the spinal chord, probably not by the medulla oblongata. Whenever, therefore, an impression received by an excitable nervous fibre is transmitted through the unconscious part of the central 20 218 HUNTER ON THE ANIMAL CECONOMY. The apparent difference in these actions would in many cases induce us at first to believe they were produced by different principles ; as in many species of the same genus of plants some open their flowers in the day, others at night (as in the Mesembryanthemum, or fig-marigold), similar to that which is the ceconomy of some animals, as in many species of the same genus of moths (Phalana, Linn.), some fly, seek their food, and procreate in the day ; while others are inactive and fixed to one spot, without apparent motion, all day, but on the approach of night become all at once animated, fly abroad, seek their food, and procreate. These actions, are nevertheless, produced by one and the same cause. The owl and hawk are similar in their food, yet dissimilar in their times of catching it: hunger is the first stimulus, animal food is the second; light stimulates the one to motion, darkness the other.* The action, however, in both arises from the same principle. These three kinds of motion in plants are influenced by various circumstances, and sometimes are all totally suspended.f This is

axis to the exciting fibre of muscular motion, the latter phenomenon is unaccompanied with consciousness or sensation. That the spinal chord, or any segment of it, possessed the power of transmitting an impression from an excitable loan exciting nervous fibre, has been known and admitted as a fundamental fact in physiology since the experiments of Whytt, Blane, and Mayo. To the latter physiologist we are more especially indebted for the most decisive experiments in proof, and the clearest enunciation, of this property of the central nervous axis. Recently the automatic animal motions resulting from this property have been grouped together moTe extensively than had before been done, and the morbid phenomena resulting from them ably traced out by Dr. M. Hall. But I cannot perceive the necessity of a distinct class of excitable nervous fibres for. transmitting an impression to the motive fibre through the medium ofthe spinal chord and brain, and of another class of nervous fibres for transmitting an impression to the motive fibre through the medium of the spinal chord alone; still less can I perceive the necessity for one class of exciting or motive fibres for transmitting the stimulus to the muscular fibre from the brain and spinal^hord, and of another and distinct class for transmitting a stimulus received from the spinal chord independently of the brain. It remains to be seen whether anatomy will establish the existence of these four classes of nervous fibres, which, so far as I understand Dr. Hall's hypothesis of the reflex function, are called in to account for the voluntary and automatic and muscular motions. There is not, however, a single phenomenon of automatic motion in parts supplied by spinal nerves which may not be accounted for on the demonstrated property ofthe central axis to transmit impressions from the excitable to the exciting nerves at any part where they are connected to it, indeof nervous fibres for conveying, in this case, the impressions to the spinal chord, distinct from a second class which are supposed to transmit to the motive fibres those impressions which are not afterwards propagated to the brain. It would appear from the text that Hunter supposed that the animal motions which are unaccompanied by consctousness were altogether independent ofthe nerves; but they can truly be stated to be only independent ofthe brain ] • It may be supposed that there is a physical cause for the one seeing only in the day, the other only at night; but it is having a much more enlarged idea of an animal to suppose that the senses are adapted to the first principle than the first principle to the senses. v ' | Similar to drowned people. CROONIAN LECTURES ON MUSCULAR MOTION. 219

generally produced by cold, and shows them to be influenced by the seasons; often this cessation takes place when much weakened by transplanting, &c. I have kept a fir alive for three years without the least growth. The second and third kind of actions commonly take place only when the first kind of action is in full vigour, because the first must produce the only parts which are capable of the second and third; and these two last can only be of service to the first when it is in full force, nourishing the vegetable and performing the action of propagation. These actions are almost entirely suspended in some animals from cold, they being in this respect subject to seasons as well as plants. This is most remarkable in the simplest in their construction, and becomes less and less so in the more complicated, they being better adapted to the various seasons. The first of these kinds of action is small and insensible, although its effects are^ great. The second is considerable in both vegetables and animals, but most so in animals. The third is almost peculiar to animals, as there are very few vegetables visibly affected by external stimulus, while all animals seem to be so. The variety of motions is greater in animals, and more purposes are answered by them, which constitutes the great difference between the actions of a vegetable and an animal; for those powers in an animal not only move themselves, but also other parts of the same body, which in many instances are so mechanically constructed as to move common matter. A remarkable instance of this is the human hand; and it is by this means all our various operations on the matter of this globe are performed. The first kind of action appears to be stronger in its power, although less in quantity,* in vegetables than in animals; for a small vine was capable of sustaining and even of raising a column of sap 43 feet high,t while a horse's heart was only capable of supporting a column of blood 8 feet 9 inches high: both of which columns must have been supported by the action of the internal parts, for we must suppose the heart equal, or nearly so, to the strength or action of the other parts of the vascular system; and when we consider that the sap of the tallest tree must be supported and even raised from the root to the most distant branches, it must appear that the power of such vegetables far exceeds the power of any animal, and indeed it is such as the texture of a vegetable only can support. The power of supporting a leaf erect for a whole day is as great an effort of action as that of the elevator palpebrarum muscle of the eye of an animal. If we consider the differences in the ceconomy and the mode of life of vegetables and animals, we shall find the increased quantity

* I make a material difference between the power and the quantity of action. Some motions may be very small, yet act with great force; while others are of considerable extent, although very weak. t Vide Hale's Veg. Statics, vol. i., p. 112, Exp. 36. 220 HUNTER ON THE ANIMAL CECONOMY. of motion of the three kinds above mentioned, and the increased power of the third kind in animals are only adapting them to those differences. Locomotion, for the purposes of procuring nourishment, concourse of different individuals for the propagation of the species, and destruction of each other, are the chief differences in animals. This power, however, is not given to all animals, and those which are deprived of it have their motion confined to the procuring food and the propagation of their species.* Many of these, although with great impropriety, have been considered as vegetables. To see if the actions of plants were affected by a continuation of stimulus similar to those of animals, I made the following experiments. As I took for granted that the analogy could go no further than as it related to the actions produced by external stimuli, my experiments were only on such plants as exhibited actions of this kind. As those parts of plants which are capable of the second and third kinds of motion are in general small, as leaves, tendrils, flowers, &c, it is difficult to discover the mechanism upon which the motion depends: the sensitive plant is probably the best of this kind that we are as yet acquainted with. As the motion of the peti,oli is confined principally to one part, and that differing from the others in external appearance, which difference is its increased thickness and uniformity of surface, upon cutting the footstalk longitudinally, as also the stem on which it stands through its whole length, the following appearances may be observed:—f For the purpose of making my experiments I took three sensitive plants, having several others for any comparative experiments which might be thought necessary. I first pitched upon one leaf in each plant which was capable ofthe greatest motion of collapsing and erection; and behind each of these leaves a board was placed, on which was marked the greatest extent of the two motions, so that the leaf was like the index or radius of an arc. To have the greatest part of the day before me, I began my experiments at eight in the morning, while the leaves were in full expansion, and I continued them till four in the afternoon, as longer than this would not have been just, for they begin to collapse of themselves between five and six o'clock.

* [The two sexes are also necessarily united in the same individual, as in all attached and pedicellate animals, from the Coralline to the Barnacle, and in many others of slow motions. See note, p. 71.] f [A blank in the manuscript here occurs, which leaves us ignorant as to the result of Hunter's examination of the structure of the irritable intumescence at the base of the leaf-stalks and stalklets of the Mimosa. With his usual sao-acity, however, he rightly refers the motive power to this part, and it has been the subject of much diligent and minute investigation since these Croonian Lectures were read.] CROONIAN LECTURES ON MUSCULAR MOTION. 221 Comparative Trials of the Action and Relaxation of Three Sensitive Plants. The time. The point they fell to. ^^S.^ The pointto which they rose. 8 o'cl'k A.M

H P.M. To the lowest point, and became sta- | tionary. "To the lowest point, | but the second' lower down. The second & third!) ' lower than lowest > point. j

Below lowest point. Below lowest point.

^ 1st only below low- ( est point,

Ditto. « Below lowest point. No.l. Min 51

32 fThe 1st and 3d rose j to the highest point ■{ the 2d not so high, and then became (^ stationary. rThe 3d rose to the J highest point, the ( 2d and 1st not so high, and then bc- L came stationary. f All three rose to with I in a little of the t highest point, and there became sta L. tionary. ( All three within a little ( of the highest point, fThe 2d and 3d to < highest point, the ( 1st not so high.

C 3d to highest point, < the 1st and 2d not f so high. C 1st and 2d to highest < point, 3d not so ( high. From these experiments we may draw the following conclusions: That there is no fixed time for the leaves of any of the plants to move through its course. That they are less affected as they become accustomed to the stimulus, but the power of collapsing is increased (although not in the same degree), so that they do not move through the same arc. That they require a stronger or quicker stimulus to produce motion after being some time accustomed to it, which was evidently seen in comparing these with others which had not been stimulated. It may also be observed that when these plants collapse in the evening they have nearly the same quantity of flexion as when roughly touched at noon; but if touched after they have collapsed from the effect of the evening, they become much more bent than by the same touch at noon. This would seem to arise from a disposition to collapse in the evening, and a power of increasing that disposition and action when stimulated. 20* 222 HUNTER ON THE ANIMAL CECONOMY. Their collapsing more in the day, and erecting themselves less after a repetition of such actions, may assist in explaining the principle on which this depends.

Relaxation in Vegetables.

There is an action in plants which appears to be the contrary of expansion; it may be considered as a relaxation, or an action of those parts antagonising the others which acted through the day, or at other periods, and takes place at the time these other parts cease to act. This action has hitherto been considered as analogous to sleep in animals, whereas sleep is a total loss of the sensitive principle and all the actions dependent on volition for the time, and therefore can only take place in animals endowed with sensation.* It is rather a defect in the animal than an action or the exertion of a principle. This action of relaxation is seen in the sensitive plant when the folioli close upwards and are kept bent by the power of action in the flexors, till light and some other of its attendants affect it, when the extensors begin to act, and this action of the flexors ceases. The footstalk dropping down favours the idea of simple relaxation; but this only arises from the position of the plant, for if turned upside down it stil| bends against its own gravity.f The one action is produced by the stimulus of light, the other by that of darkness; for if the sensitive plant is kept in a dark room it will keep bent, and perhaps as long as it lives; and if one part of the plant is kept in the dark and the other in the light, that in the dark will be bent, and continue so, while that in the light will expand itself. Light and darkness become stimuli to the same plant, and have much more influence over vegetables than could at first be imagined. Many plants only grow through the day, others only grow after it is dark. Sympathy in Vegetables. Sympathy is the action of one part in consequence of an application being made to another part, or action in another part. This power of action is extended to few plants, and even in these appears to have little variation. It is evident in the sensitive plant; for if one of the little leaves be wounded at its termination it will collapse immediately, as also its fellow on the other side. This action runs through the whole of the rachis of the compound leaves, the leaves bending regularly in pairs.

* The polypus does not sleep. t [The powers which produce the depression and elevation of the leaf-stalk operate in a manner precisely the reverse of the flexor and extensor muscles in animals, pushing the moving part from, instead of pulling it towards, the fixed point. See Mayo's Physiology, p. 9 et seq.] CROONIAN LECTURES ON MUSCULAR MOTION. 223

If it is a middle foliole that is wounded the same thing takes place ; they all collapse towards the foot-stalk, but seldom towards the extreme end of the leaf, and in a little time the rachis is inflected and the whole leaf drops at the trunk. It may be remarked that a small flexion takes place towards the tip; but this principally arises from a disposition in the folioles, for a middle one cannot collapse without pressing or folding a little on the one next to it towards the end ofthe leaf which stimulates it and makes it collapse. It is evident in the tendril of the vine, for these tendrils generally divide into two, near their ends: these two going out from the principal trunk in different directions, if one lays hold of any body and twines round it, the other immediately alters its direction and gradually approaches the same body till it comes in contact with it, and then bends round it and encircles it. This motion, however, is very slowly performed. Sympathv in plants is very slow in producing its actions ; the succession of stimuli in them being slow, the consequent actions must also move slowly along. Plants have but one mode of sympathy, which arises from stimulus. Animals with no brain or nerves have but one also. Those, however, endowed with sensation have three: they have one mode from stimulus, one from sensation, and one compounded of both. Sympathy in animals, arising from stimulus only, is slow, as in plants ; but sympathy from sensation is often very quick.

MOTION IN ANIMALS. Muscles would seem to act by vibration, although in a strong healthy man they are so short as not to be observed; yet if the muscles are made to act beyond their powers they plainly vibrate, but still more plainly in weak constitutions. The weaker a muscle is, the longer would seem to be the vibrations, for if a weak person holds anything out in his hand it shakes. In paralytic cases, whenever they are put to the smallest action, the vibration becomes very long, and the less the action the shorter the vibration. Fear also increases the vibration in proportion as it weakens the muscle.*

* [The first part of Dr. Wollaston's Croonian Lecture for 1809 is devoted to the illustration of an opinion on the nature of muscular motion, corresponding with that which Hunter has above enunciated. Dr. Wollaston, as is well-known, was led to infer that each act of contraction, apparently single, consisted in reality of a great number of contractions, repeated at short intervals, by reflecting on the sound perceived upon inserting the extremity of the finger into the ear. This sound, which resembles that of carriages at some distance passing rapidly over a pavement, is not perceived when the force applied to stop the ear is not muscular, unless the action of some distant muscle be communicated through some medium capable of conveying its vibrations. From experiment, associated 224 HUNTER ON THE ANIMAL CECONOMY. The Causes of Action in Muscles.

The actions of muscles have been hitherto attributed to the nerves as a cause; the mode of action of the nerves, however, not being known, most physiologists have thought themselves obliged either to make a new hypothesis, or support an old one; in all which they make it mechanical, depending either upon the motion of a fluid, or the vibration of a solid, or vapour ; but there is not a single known fact attending the nervous system which could either give rise to, or support, these hypotheses, except the distance between the seat ofthe will and a voluntary muscle; and they have consequently been such as few thinking men could adopt. As the brain and voluntary muscles are, with respect to our senses, in two different places, and are connected together by the nerves, it might be supposed there was some fluid in motion that would convey the impression to the mind, or the will of the mind to the voluntary muscles; but these informations are very probably the effects of sympathy. I am afraid we can go no further in the investigation ofthe cause of the action of muscles than by observing the phenomena which happen, and these all lead us to one cause of action. The visible external cause of the action of a muscle is called ' stimulus,' and it is reasonable to suppose that all causes of such action are similar. This, however, may admit of dispute, the heart certainly having no visible stimulus for its motion, except the being called upon, by the sympathy which subsists between the combined powers of the animal ceconomy, to exert itself in their favour, which will not account for the heart's motion when removed from that connexion. The great question has hitherto been, whether a muscle is susceptible of impression without the medium of a nerve, or whether a nerve is in all cases necessary to its being called into action; for a stimulus must either affect the nerve which affects the muscle, or the muscular fibre itself must be susceptible of immediate impression from the stimulus. A muscle would appear to be capable of being affected in both ways, for many animals certainly exist without nerves, and plants are susceptible of stimulus where it must be immediate, they never having been supposed to have nerves.* It is also evident in aniwith the above observation, Dr. Wollaston concluded that the vibratory alternations recur between twenty and thirty times in a second, varying in proportion to the degree of force exerted by the muscle ; the greatest number being estimated at thirty-five vibrations in a second, and the lowest at fifteen. The more obvious illustrations of this mode of muscular action, presented by the aged and infirm, are also adduced by Dr. Wollaston, who, without doubt, was quite unconscious ofthe conclusion previously drawn by Hunter from the same phenomena.] * [Those who admit that a muscle is susceptible of stimulus only through the medium of the nervous matter blended with its substance, do not scruple to ascribe CROONIAN LECTURES ON MUSCULAR MOTION. 225

mals with nerves that by stimulating a nerve the muscle to which it goes will be immediately thrown into action, the nerve becoming the immediate stimulant, so that a muscular fibre may be stimulated by a nerve as well as by any other impression. The modes of stimulating a muscle will be different according to the nature of the animal or of the muscle. In the more simple animals they will be few, increasing as the animal is more complicated. The first kind of stimulus is that common to all animals and vegetables, which regulates the internal machine, producing growth, preparing the parts of generation, &c, &c. The second is the internal stimulus, which respects external matter for the support and continuance of the first, as that producing breathing, hunger, the desire of propagating the species; all of which are common to vegetables as well as animals, and require the assistance of a third kind to complete the action. Vegetables are supposed with great reason to have an action analogous to breathing, for the same kind of air which kills animals which do breathe, certainly kills vegetables also.* Vegetables imbibe nourishment, which action arises from the same stimulus as in animals. They also require the stimulus of certain operations to be performed upon them by external matter to enable them to propagate. This external matter is either some other part of the same plant, as in the Marchantia polymorphia calyce decemfido, which has the filaments almost constantly in motion striking the antherae.t

nervous or sensitive globules to vegetables. But they here c.eate the necessity which an undemonstrable organ is called in to supply. Now the more simple and philosophical mode of considering this question seems to be to examine whether the moving organs are stimulated in any. new, distinct, and additional manner in those organized beings in which nerves have been detected; and if it be found that they all manifest spontaneous actions,—motions of parts independent of any external stimulus,—a phenomenon which has never been witnessed in any plant, then the next step would be to determine by experiment the relations subsisting between the new function and the superadded organ. The irritable fibre does not contract in a different manner when stimulated by the will than when stimulated mechanically out of the body; nerves, it is true, convey impressions which excite action, and are essential to the application of the voluntary stimulus, but not, therefore, to the muscular contraction. Hence, when we come to account for the cause ofthe spontaneous actions in animals in which no nerves have been detected, we are justified, by analogy, in attributing the spontaneous stimulus to the presence of undemonstrable nervous matter. But in the case of plants, if we attribute the contractions to anything but the irritability of the moving parts themselves, we must first hypothetically assume that nerves are necessary for the action, and then gratuitously infer their existence. This, however, only leads to a greater difficulty, to account, viz., for the non-existence of spontaneous motions in those organized beings to which nerves are, in the above theory, attributed.] * [As azote, hydrogen, or any gas deprived of carbon and oxygen ; for though vegetables in health and sunshine give out oxygen, they absorb that gas, and emit carbon, but in less proportion, during the night.] t [In the barberry the filaments supporting the mature anther, when touched, bend towards the germen. In the tigor-lily the female part of the flower is endowed with irritability, and the style bends first to one stamen, then to another.] 226 HUNTER ON THE ANIMAL CECONOMY. The filaments ofthe flosculae ofthe thistle produce the same effect or it is done by some foreign stimulus, as the wind, driving the pollen of the male plants against the germina of females.* Most animals perform these actions themselves, yet in both animals and vegetables a similar stimulus is necessary. The third kind of stimulus is from external or extraneous matter immediately applied to the part, which is also common to animals and vegetables. The fourth kind of stimulus arises from the nerves, which we may reckon twofold; one in consequence of the nerves being impressed by external matter, the other from their being impressed by the brain, or sensorium. This is peculiar to animals, many of them receiving intelligence from without, which becomes the regulator of their actions towards that matter which gives the intelligence. This leads us immediately to voluntary actions. The actions of muscles have hitherto only been considered by physiologists in the more perfect animals where this (the voluntary or nervous stimulus), is given, which becomes a different cause of action from those found in other animals and vegetables. Those actions where the mind, being made sensible of them, may be considered as a cause, are called voluntary actions; and those actions over which the mind has no influence, and about which it is not in the least consulted, are called involuntary actions. The actions of the muscles which go on without the influence of the mind, but can be restrained, increased, or stopped by the mind, are called mixed. There are also actions which may be allowed to arise from a peculiarity in the state of mind, but not dependent on the will: these are common to both the voluntary and involuntary muscles. Thus an involuntary muscle, as the heart, increases its strokes, and the voluntary muscles of the hands, legs, tongue, &c, tremble when the mind is agitated by anger, fear, &c. These four kinds of action not only appear to arise from different causes, but produce different phenomena. The first kind, or voluntary motions, last only for stated times, beyond which they cannot go, the muscles either losing the power altogether, or the mind becoming incapable of stimulating them; by which means a cessation of action takes place, which indeed is necessary for the preservation of the animal. For these actions, too long continued, weaken, hurt or destroy the body; and therefore the mind which is under no restriction is thus prevented from continuing the action. We have this beautifully illustrated in some of the mixed motions : for where their involuntary motions are employed for the preservation of the animal, as in breathing, they are constant; and where the stimulus of necessity does not constantly

* The anthers of vegetables requires some motion to make them burst; some ^5?,/^ P°aTi° ffpr°fduCl^ thls motion' but if lhe power is given they burst immediately. A b ast of wind is often necessary, and in such plants propagation does not go on well in a calm place. p t"«F°s CROONIAN LECTURES ON MUSCULAR MOTION. 227

take place they rest, as in the stomach, levator palpebrarum, &c.; but if we voluntarily increase the actions of these they soon tire. The natural involuntary actions of muscles are such as never tire, while the voluntary always do ; and we may observe that the muscles which are under the influence of both are never tired of their involuntary actions, while they are of their voluntary. This we might suppose was owing to this property being stamped upon them at first, and for very wise purposes ; but it rather appears to be a property arising from the mode of impression, viz., not being impressed by the will, but probably acting from a general impression in the machine, viz., from general principles; whereas the voluntary actions are caused by a peculiar impression of the will, and the muscles are so constituted as to tire of that impression, or rather become incapable of acting, which gives the sensation called tired. But this is carried further, for in muscles that are entirely at the command of the will, if they take on involuntary actions they never tire. For instance, Lord L----'s hands are almost perpetually in motion, and he never feels the sensation in them of being tired. When he is asleep his hands, &c, are perfectly at rest; but when he wakes, in a little time they begin to move. We tire of voluntary actions whether of voluntary parts or of parts that commonly act involuntarily, as the muscles of respiration. Tiring of action feels to the mind to be in the muscles themselves, but I imagine it must be in the mind, although it is referred to the muscles; for we cannot suppose that the mode of action of a muscle directed by the will is different from the mode of action when not directed by the will. This is not a tiring of the will itself, but probably a tiring ofthe action ofthe nerves ofthe will; and as the actions of these nerves is always referred to the part of their destination, the tiring is also referred there. The second kind are the involuntary actions, which are lasting, as the parts themselves : these are always fit for action ; and if they are inactive, it does not arise from the want of power in the part to act, but from a cessation ofthe stimulus, which cessation takes place whenever the action, from peculiar circumstances, is become unnecessary. Such actions are naturally so circumstanced as to be constantly wanted, being for the preservation of the animal, as the motion of the heart. The nerves are only to be considered as conductors carrying impressions from every part of the body to the brain, or carrying the command of the will to those muscles whose actions can only be employed about such external objects as can affect the mind; but those parts whose actions are unknown to the mind appear not to be affected at all by the will. That the nerves are the principal agents between the mind and the parts would appear from circumstances respecting their comparative size; for all those parts which convey a strong sensation, or are intended to perform extraordinary voluntary actions, have large nerves; while those parts of animals which neither give intel- 228 HUNTER ON THE ANIMAL GECONOMY. ligence to the mind of their actions, nor are under the influence of the mind, have very small nerves. A stronger instance of this cannot be given than the electric organ of the torpedo, where the power of giving or restraining the shock depends upon the will: the actions are strong and violent, for he can soon exhaust himself by them; and the nerves which convey the power of the mind exceed, compared with the size ofthe animal, in bulk the nerves in any organ of any other known animal. It is a part whose actions, its growth excepted, depend entirely upon the will, having no power of action of its own ; the communication between the will and the organ is large in the same manner as the communication between the senses in general and the brain is large. The voluntary muscles have large nerves to command the action of the muscle, which is independent of the will, although in some degree subservient to it; but they are not so large as those of the senses or electric organs, where they give the part its whole action. A nerve being cut going to a voluntary muscle, the muscle cannot obey the will, and thereby loses its voluntary actions; but it may be stimulated into action by immediate impression from other causes, as electricity. The voluntary and involuntary muscles having their quantity of motion in an inverted proportion to their quantity of nerves, is a strong argument against the nerves being the cause of muscular motion. If it is asked why the involuntary parts have nerves at all, the answer may be given that it is not for their common actions, but to keep up the connexion between the whole, for without them an animal would become two distinct machines, and one might be acting very contradictorily to the other; but by the intercourse between the will and voluntary parts, between the voluntary and involuntary, and also between these last and the mind, an universal and uniform agreement or regulation is kept up, which communication produces one kind of sympathy. This connexion between the living principle and the sensitive produces a compound action, which becomes the cause of the instinctive principle in animals. Muscles are either employed upon the internal operations ofthe animal, as the heart, muscles of respiration, stomach, intestines, &c, or upon external matter for the support of both, as those of the extremities. The first of these are nearly of the same strength in the robust strong man and the small woman or man, if equally healthy; and it is right it should be so, for the small man has nearly the same resistance to cope with; but it is the others which constitute the strong or weak man. The power of muscles which are influenced by the will, although they have a common power of action with those independent ofthe will, sooner lose their powers than those which are wholly involuntary, as the heart, stomach, bladder, blood-vessels, &c, which CROONIAN LECTURES ON MUSCULAR MOTION. 229

would seem to show that the power of simple life lasts after the will is no more. We might naturally suppose that the voluntary muscles have nearly the same quantity of power of action as the involuntary; but upon considering several circumstances, we should rather conceive the contrary ; for when wre consider the power by which the colon of a horse propels such a load of solid contents, we can hardly conceive the power of any voluntary muscle of the same thickness equal to it. For, as voluntary motion arises from two causes, or has two causes of action, the moment one of these ceases, the power which remains is either not so strong originally as the whole power of the involuntary muscle which has only this principle of action, or not so strong, from want of habit, not having been always employed as a principle of action in them. It is not clear to me but that every muscle has a sphinctorial power of contraction so as to bring them to the middle state. This we may see in the temporal muscles ; for by opening the jaws the muscle sinks, and by leaving the jaw to itself, not acting with it in the least, the jaw rises and the muscle in part fills up, so that the jaw is suspended by the half action of the muscle ; however, this power may be much more in some muscles than others. The great variety of causes of muscular motion make it almost inexplicable: they may be said to be three,—the will, passions of the mind, and external stimuli. Those actions arising from the will and the mind appear to be most simple, because they are totally unintelligible; but those arising from external stimuli are either voluntary or involuntary, for a muscle that acts by the command of the will at one time is also capable of being thrown into action by a particular state of mind or external stimulus. Those actions which arise from the will have reason and habit for their continuance ; they are such as arise out of imitation, reasoning, and all the powers collected by the senses. Those actions which arise from the mind belong mostly to the passions, which affect more muscles of the body than the will; perhaps there is not a muscular fibre in the whole animal machine but is at different times affected according to the different affections of the mind, every different state oi* mind having its particular muscles to stimulate. Upon many of these occasions reason is introduced, which is provided by this slate of mind to call in the assistance of other muscles, to act according to that state, either to bring about an increased action which will destroy itself, or to prevent the increase and continuance of those actions. From extraneous stimuli arise all our internal insensible actions, and these depend upon the principle of simple life, upon which depends also the action of medicines; and health is only the right action of such parts. , Some muscles must be put upon the stretch, and they will continue their action far beyond the easy point, or that which was so 21 230 HUNTER ON THE ANIMAL CECONOMY.

before this action, as the stomach, intestines, and bladder. Others wait to be stretched, as the uterus; this, however, is not the cause of its contracting again, it is only putting it in a state to act when another cause takes place, as a miscarriage or fcetus at the full time. This is nearly opposite to the other, for what endeavours to empty or relax the uterus becomes the cause of its contraction, not what stretches it. Voluntary actions, when very violent, produce involuntary, as the cramp, from dancing, swimming, &c. We feel every involuntary action of a voluntary muscle, while we do not feel the voluntary actions ; nor do we feel the actions of an involuntary muscle. When such actions are slight we only feel them as little convulsions, contractions in different parts ofthe body, called creeping in the flesh, or quivering in the eyelids ; but when these become violent, as in cramps or spasms, then the sensation is pain. Voluntary muscles, the stronger they are, the more they are at the command of the will; and the weaker they are the more they seem independent ofthe power ofthe will, and seem to be either at their own command, or at that of the nerve. Strong people are less subject to spasms than weak, which may perhaps arise from custom ; the strong muscles being more healthy, are oftener in use, and therefore become more at the command of the will. Women, children, and sick men are subject to fits, for the reason just mentioned ; perhaps also diseases of the uterus, for the same reason, are the cause of spasmodic complaints, it being very little at the command ofthe will, but of other circumstances; and from this disposition draws in other parts by consent, and so brings on general spasm. Voluntary muscles always become tired when long continued in the same action, which accounts for animals tiring sooner by being kept in one position than if allowed to move ; and we find a man can hardly stand five minutes in one position ; he never stands equally upon both legs, but upon one as a base, the other as a prop, so as to be able to shift his legs as they tire. Animals, also, by moving or producing alternate motions by their muscles, can go on for a considerable time, but their alternate motion must not be quick, as it always requires a certain time for muscles to regain the power which they lost in action, and if the alternate motion becomes quick and violent, it may tire sooner than constant motion. The voluntary actions of young animals are not so strong, and are much less lasting than those of middle age; that strength they have they are not capable of employing for any great continuance without tiring, especially in actions where a considerable force is required. Thus we have young horses soon fatigued with labour, which the same horses will easily perform some years after. This ability in the older horse does, not arise entirely from a naturally greater degree of strength, joined with a natural capability of continuance, CROONIAN LECTURES ON MUSCULAR MOTION. 231

but in some degree from an acquired strength from employment, and a capacity of endurance from the habit of action. This might be thought sufficient to account for the whole difference, but dealers in horses affirm that one of seven and one of four years old, having equally done no work, shall not be equal in their continuance of it. In riding they also give weight according to age, and the aged horse always carries the greatest weight, if other parts are equal.* When an animal is at its full strength is not easily ascertained, but it cannot be while growing; it must have arrived at its full extent, and perhaps it is even necessary to have been some time in that state. The involuntary actions are stronger before this period than after; this is perhaps necessary for the animal's growth. Besides the decrease in the size of a muscle from an atrophy, etc., and the restoration of them again to their natural size, which is disease and health, there is an increase which accompanies the whole body, till it arrives at its full size, when the whole seems to rest, except the muscles. How long the muscles continue in this full size is not easily ascertained, but when old age begins to come on, the muscles begin to decay; but not becoming pale and flabby, like a diseased muscle, but retaining their redness and sound appearance. A person grows thinner after a certain age, but not in proportion to the decrease of size of the muscles, for the interstices between the bundles of fibres, and also between the muscles themselves, are loaded with fat, and this takes place so constantly that an old man may be distinguished from a young one from only seeing the muscles, and the fat mixed with them. Muscles in old people lose their quantity of contraction, and the joints are therefore never moved to their full extent. This is the loss of only the extreme motion, which is weak, and therefore may be supposed to arise from weakness alone; but I do not think this effect is produced in young people from weakness. An old man stands with his knees, thighs, and all his joints bent, not being able to bring himself to the upright position. The actions of the body that are both involuntary and voluntary are some of the most beautiful circumstances in the machine. I believe the muscles of respiration are the only perfect instances of it. The sphincters also have both; but in them it would seem to be an involuntary continuation of an action which is voluntary. Fresh air was necessary for our existence, and it was therefore necessary that it should be regulated by some other principle than that of the will; for it is necessary when we sleep, and also when we will the contrary. Therefore our will has its limits of power over the involuntary actions, and the involuntary also have their limits over the actions of the will; each therefore can only go a certain length in opposition to the other. As all animals which breathe air are probably endowed with the

* How accurate these gentlemen are I don't know. 232 HUNTER ON THE ANIMAL CECONOMY. power of forming sounds, and as air is in common necessary for such an effect, Nature has made this air answer the purpose of sound as well as of life. For the purposes of life it was necessary the action should be kept pretty regularly constant, and therefore involuntary, because it required too much attention of the will to keep up the necessary action, and the will is not always in a state to attend to it; but for the purposes of sound it was necessary it should be at the command of the will, for sound is in some degree arbitrary : for although often attended or caused by a natural propensity at the time, yet it can be avoided, as in crying. Vocal sounds, however, do not entirely interfere with inspiration and expiration ; it is performed by the last, which must have been preceded by the first, although not with the same ease. Many other actions ofthe body interfere with involuntary respiration ; all violent exertions of the body are a check upon it; but then in proportion to the intended exertion, the voluntary supersedes the involuntary, and they take in a proportionate quantity of air; but, both in sounds and exercise, if continued, the stimulus of necessity for a repetition of respiration takes place, and the person is obliged to take in a fresh supply of air, which again answers the former purpose.

The Colour of Muscles. Most parts of an animal body are white, and when they have any other colour it generally arises from some adventitious though necessary matter, as the pigment of the eye, which in many persons is black, in some green, in others white, &c.; also the pigment of the skin, which in many people is dusky in its colour. A muscle in all animals is in itself white, and its red colour found in living animals, and also immediately after death, arises from the blood ; for if a red muscle be steeped in water it will become white; or if the arteries of a part which has red muscles be injected with water till it returns by the veins, the muscles soon become white. A red muscle exposed to the air loses the Modena red, becoming florid. As the colour of muscles arises from the blood in their vessels, the muscles of every animal must have the same colour with the blood; if the blood is red, the muscle will be more or less so, according to its quantity ; for in sick or unhealthy people they are

If the blood is of any other colour the muscle will be tinged with that colour, and also in proportion to the quantity of the blood. All muscles, however, have not the colour of the blood, for many animals having red blood have their muscles almost white; and even in the human body many muscles are much redder than others. The muscles of an arm or leg are much redder than those of the stomach or intestines; those of the face are much paler than the temporal or masseter, although nearly in the same situation. CROONIAN LECTURES ON MUSCULAR MOTION. 233

The muscles of quadrupeds are not equally red, there being a great difference between those of a hare and rabbit. The difference in the colour of muscles in the same animal, and in different animals of the same order, is very remarkable, but is equally to be observed in another order of animals, viz., fowls. The blood in fowls is red; there are few, however, in which some muscles are not much redder than others, and in some birds they shall be almost wholly red, as in the black cock, while in others they shall be nearly all pale, as in the turkey. The muscles of birds are more generally pale than those of quadrupeds, from their having a smaller proportion of red blood, and that blood being more partially distributed. The muscles in frogs, snakes, tortoises, &c, are generally pale, from their having a still smaller quantity of red blood, and that quantity more confined to the vital parts than in birds. The muscular parts in fish are generally white, although I believe they have all red blood, but in smaller quantity than even frogs and snakes, so that the motion of red blood in them is much confined in its extent, appearing to go no further than those parts which are essential to life. The muscles of many animals of a still inferior order are generally pale;, the blood in them being not apparently of any colour, and in some almost transparent, as in the lobster, oyster, snail, &c.; and in this order of animals, if the blood is of any determined colour, it is generally so confined in its motion, not running minutely into parts, that they are hardly tinged with it, as in the slug, which is black, although the blood" is of a milk white. The earth-worm, however, is an exception to these general observations on the more imperfect animals, for it has a great deal of red blood, which is seen through the whole body of the animal, from the external covering being pretty transparent. The red blood in a muscle is in proportion as the red blood in the animal is to the quantity of muscle; and also in proportion to the quantity of action in the muscle and the quantity of red blood taken together. The blood in the more perfect class of animals, as man and quadrupeds, and in which class whales are also included, is in greater quantity, and more loaded with red particles, than in other inferior orders;* therefore the muscles are in general redder, and the quantity of blood in this order of animals, and perhaps every other order in which they have red blood, is rendered greater by increasing the action of the muscles, the blood being driven or extended further into those parts by their increased action. This happens commonly in voluntary muscles only ; the involuntary,

* [From the numerous experiments of MM. Prevost and Dumas (Examen du Sang, Bibl. Uni. de Genev., t. xvii.), it would appear that the red globules and fibrin are most abundant in the blood of birds, in which respiration is most active and animal temperature highest.] 21* 234 HUNTER ON THE ANIMAL CECOxNOMY. being employed in uses at all times equally necessary, are even and constant in their action. Muscles much at rest are pale, as in animals just come into the world, before the muscles have had much action, except the heart, which has been acting from the beginning; and all the muscles of a young animal, except the diaphragm, may be kept pale by keeping the animal in a state of rest,* for in that state the blood does not pass far into the muscle; but as the animal grows up, the muscles become redder and redder, especially if they are allowed action by the animal taking exercise, and nearly in proportion to that exercise. This, however, is not universally the case ; for the natural actions of a hare and rabbit are not very diflerent, yet the muscles of a hare are very red, and those of a rabbit pale; whereas I do not believe it possible by rest alone to make a hare's pale, although by rest they will become proportionably paler.■(• This difference in animals so nearly allied would seem to arise from an original law in their nature; for although a hare may not have a greater quantity of motion in common, yet it is formed to be always in such a state as if it really had, that it may be constantly prepared to undergo such motion. The rabbit has no occasion for such a state of muscle, its sphere of action being much confined, and it is even not intended to run fast.. In an inferior order of animals, where the quantity of red blood is not so great, and the destruction of voluntary action not nearly equal through the whole muscular mass, we find a great difference in the colour of muscles. A bird has two kinds of progressive motion, flying and walking. Some principally fly, others walk,J and many perform both equally. In the walking bird the muscles of the leg are the reddest, as in the pheasant, partridge, and common fowl. In the flying bird the muscles of the wing are the reddest, as in the swallow and woodcock.§ In the frog, snake, turtle, alligator, &c, there is but little action, and the muscles are nearly equally employed through the whole animal except the heart; so that there is not that difference in colour in the muscles of the same animal, or of any two of this order, although in many it may be observable. In fish we find a good deal of difference in the colour of muscles, and the heart, which is in constant action, is in them as red as any

* This becomes a distinguishing mark between the hares of a barren mountainous country and a rich flat one. t Such is the method of preserving veal white, for the proportional quantity of red blood is not allowed to increase or go far from the heart. X Swimming in fowls I consider as walking, both being actions ofthe legs. § Epicures are sensible of this; therefore white veal,"the leg of woodcocks, are delicious bits, and the feeders of domestic fowls indulge them. They rob the appetite, however, to please the eye, the flavour generally being in the muscles of action. CROONIAN LECTURES ON MUSCULAR MOTION. 235 other animal.* The natural history of fish is very little known, but what variety there is we may attribute to the cause above mentioned.f The actions of the more inferior orders of animals we shall not at present enter into. From the above observations we may conclude that red blood, in those animals that have it, is of essential use to muscular contraction. That the quantity of red blood brought to a muscle is of service in its action is plain; for a muscle become paralytic from an injury to the nerve, or an anchylosis in the joint preventing its having contracted for many years, is found white, small, and somewhat ligamentous, retaining however a degree of transparency and gelatinous consistence, so that a muscle may become paralytic from too much rest alone. The wasting of a limb which is seen externally takes place principally in the muscles, more especially where they are paralytic from an anchylosed joint; in that case the muscles alone can be supposed to be affected, they alone being concerned in the motion ; but where it arises from a defect in the nervous system, that defect maybe in all the nerves of the limb, and therefore all the parts may suffer alike.

We may suppose that the blood is of great use in muscular contraction ; for in violent and frequent actions of the muscles they swell and become considerably larger, not when in action only, but when relaxed immediately after the action, and will continue swelled for some time. This swelling does not come on till the muscle is tired of acting; this must be from a greater influx of blood at that time, or that the action does not let the blood pass so freely through the veins. It must be owing to something of this kind which happens to animals which.use much violent exercise, and are killed during the action, that they are redder, fuller, and eat much tenderer, but do not keep so long. There is a material difference between a hare or deer that islhot and one run down by dogs.

* [Most of the above facts, with their physiological inferences, were known to Grew, who alludes to them in the following digression while describing the digestive organs of the bird: "And as the strong and continual motion of all these muscles is taught, us from their structure, so likewise from their red colour, which, especially in the grinders" (the lateral muscles of the gizzard,) "is intense. Hence in a fish the muscles which move the fins are usually red although the rest of the flesh is very white ; and so the leg of a domestic fowl. Whereas the winffs also of a wild fowl are of the same colour. So likewise the flesh of a driven calf, or of a hare, though that of a coney be white. And that which comes nearer, the heart in all creatures having the like continual motion is of a red colour."—Anatomy of Stomachs and Guts, fol., p. 41; lbBl.J t [See note, p. 170.] 236 HUNTER ON THE ANIMAL CECONOMY. Muscles not only become really larger by acting, but also become larger in the time of acting, and for that time only, subsiding gradually after the action is over: this increase is in proportion to the violence of the action at the time, and appears to go on till they are tired, and is probably one cause of their being so. In order to ascertain this fact as much as possible, I made the following experiments. Immediately after getting up in the morning, having used my arm as little as possible, I measured the circumference of my right arm across the belly of the biceps flexor, while in the relaxed state of all the muscles of this part, and found it measured ten inches and a half. I then bent the fore arm, in which action the biceps being contracted, 1 measured it again at the same place, and found it twelve inches one-eighth, so that this part of the arm had gained one inch and five-eighths. After having thus ascertained the size of the arm, both when all the muscles were relaxed, and also when contracted, I next worked an air-pump for about ten minutes with considerable violence, when my arm became quite tired. On repeating the above mensurations I found my arm in the relaxed state eleven inches and five-eighths, and in the bent state twelve inches and fiveeighths ; so that the arm, by acting ten minutes, had acquired an increase of six-eighths of an inch in circumference even in the relaxed state of the muscles, and four-eighths in the contracted state. That the calf of the leg swells towards night is a common observation ; and 1 suppose it is principally owing to its having acted so much through the day. That the swelling in such cases is in the muscles themselves is evident from the stiffness felt in acting with tired muscles. What produces this temporary increase in the muscle? It is probable that an extravasation of fluids has taken place, and the weakness induced in the muscles in consequence of their having acted more than usual, and with greater force, is the cause of extravasation.

Effects of Habit on Muscles.

Muscles are capable of being improved and increased in different ways by exercise, or employing the muscle much in its natural functions. This improvement in action is most observable in the muscles of volition, as it is in consequence of the will that they become more familiar with the actions; and also they are more subjected to a variety of action, sometimes acting strongly, at others not at all. ° & J The stimulus of the will never loses its influence by habit or by becoming familiar, but these stimuli may be called arbitrary or accidental, foreign, &c. Muscles not only improve in one particular, but in every respect whatever. CROONIAN LECTURES ON MUSCULAR MOTION. 237

One improvement voluntary muscles acquire from habit is the readiness with which they take up their own actions, the will frequently only having to set them a going; there are instances of people playing tunes without attending to the notes or even thinking ofthe tunes. From this facility of obeying the will in beginning actions, and of repeating actions they have been accustomed to, with the greatest variety of motions, in the voluntary muscles, particularly in man, and also from the frequent employment in any actions, muscles acquire a facility in obeying the mind in the performance of actions they had never tried before, going hand in hand with the mind; for as the mind, when it sets the body to perform actions, acquires a facility in immediately employing the proper muscles, they obey directly, and this even in actions they never performed before. A man will learn one trade much more readily if he knows another, than if he knew no trade at all. The habit of acting in a muscle, especially when employed in considerable exertions, increases the necessity of becoming stronger, which necessity, acting as a stimulus upon the muscles, becomes a real cause of increase of size, which augments their strength. This effect is so evident, that painters and sculptors, as well as physiologists, have observed it. We have Charon and Vulcan always represented with large shoulders, brawny arms, and their lower extremities small, and apparently disproportioned. This effect is still more nicely marked by the difference between the right arm and the left; the right being generally employed in preference, and more particularly in great exertions, is therefore the largest and strongest. People who play much at tennis, where the ball is always struck with the right hand, have that arm much thicker and stronger than the left; therefore a man originally wellproportioned shall lose that proportion by being employed in any action that does not require the whole body. From these facts it must appear, that if every animal was perfectly made, with respect to any standard proportion of its parts, that few would be allowed to grow to that standard, because few animals exert all their muscles equally, there being in most some circumstances in life which oblige them to exert one set of muscles more than another. This is probably more the case in man than in any other animal, and also in him less determined to any one set of muscles more than another; it, however, also takes place in animals, as there will be a considerable difference in the muscles of two birds' breasts of the same species, one being allowed to fly, and the other kept in a cage. The increase in the voluntary muscles appears not to be without limitation, and indeed if it was we might see them increase beyond conception. What principle sets bounds to this increase from action is not known; the circumstance of these muscles tiring may become a cause. 238 HUNTER ON THE ANIMAL CECONOMY. This increase is not confined to the voluntary muscles, for the involuntary, when obliged from any circumstance to act with uncommon force, also enlarge, and become stronger, and in a much greater degree than the voluntary. The bladder has been found exceedingly thickened in its muscular coat where there are either strictures in the urethra or stones in the bladder, for in this last complaint, although it discharges the urine, yet it continues to act with more violence than usual, being irritated by the stone, which it cannot expel. I bave seen it increased to three times its natural thickness.* Increase of thickness in the auricles and ventricles ofthe heart, in consequence of an aneurism in the arch of the aorta, is not uncommon. The cremaster muscles I have seen very much enlarged in cases of hydrocele of long standing. In the increase of involuntary muscles there appear to be no limits: the power of increasing seems to be in proportion to the necessity, and as they do not tire there is no end to their power of acting. Whether this increase of the body of a muscle is a new addition of muscular fibres, or an increase in size of those already formed, is not easily determined, but I should be inclined to suppose the last. 21. CROONIAN LECTURE ON MUSCULAR MOTION, NO. II. [Read before the Royal Society in the year 1797, by John Hunter, F.R.S.]

THE CONSTRUCTION OF THE ANIMAL MACHINE WITH THE MECHANICAL EFFECTS PRODUCED BY THE MUSCLES AS MECHA NICAL POWERS.

Mechanical arrangement ofthe Fibres of Muscles. The most simpje mode of investigating an animal body is first to consider the matter of which it is composed. In this inquiry we shall find it more than probable that there is but one species of matter which is peculiar to animals, and therefore I shall call it animal matter. The blood appears to be the most simple modification of this matter: it is the material from which all the solids are composed. The next modification, or what may be called the simplest organization, is a certain arrangement of this matter so as to produce some action. This may be of two kinds: first, such an arrangement as may take place in any kind of matter, so as to produce elasticity. The second is such as is capable of producing

* [Hunter has preserved many preparations in his Pathological Series illustrative of this fact, as Nos. 746, 752,755, 758, 759, and 961, &c] CROONIAN LECTURES ON MUSCULAR MOTION. 239

a motion in itself, without the cause being mechanical as in elasticity : this is the composing of a muscular fibre. A muscular fibre is one of the simplest constructions of an active solid, and it is these fibres which compose almost the whole of many animals. The muscles are the powers in an animal body, and are perhaps the most regular parts of the whole. They are apparently constructed of fibres laid nearly parallel to one another ; in some they are extended longitudinally from one end to the other of the muscle which they compose; in others their direction is oblique to the body ofthe muscle; this obliquity in some is regular from one end of the muscle to the other, while in other muscles the fibres lie in contrary directions. In some a number of these oblique portions compose the muscle; the parallelism, however, in each portion is preserved. This parallelism is only found in some of those muscle whose fibres all tend to one point of action,.and they are nearly of equal lengths in every part of such muscles; but where parts of a muscle produce different effects the fibres vary in length, suited to the quantity of motion admitted by the directions of the joints. The most simple muscle in an animal body is a bundle of "fibres, distinct from end to end from all other portions, and having one determined use. The muscles which move the globe of the eye come the nearest to the idea of a distinct muscle; however, there are very few muscles in an animal body so unconnected with other muscles, which makes it difficult in many cases to say with certainty what may be called a distinct muscle. If we take a view of what we call muscles in an animal body, the human for instance, we shall find that no definition can be given which will answer to them all. A muscle is said to be distinct if it is so at its insertion only, although it may be connected with others at its origin, as the extensor indicis proprius. A muscle is distinct, although connected with another at its insertion, if there is a difference in the use; or although connected at its origin with one muscle, and at its insertion with another; but where two portions of flesh are united at their insertion, both having the same use, they are considered as one muscle. So that it is the particular effect which is produced by a portion or portions of flesh which in general has made anatomists either unite or divide them into separate muscles. This, however, has not been universally followed; for in some particular muscles, in which the origin is of considerable extent, and the insertion but small, each part of the muscle having the power of acting separately, and producing different effects according to the parts which act, (the joint admitting of a variety of motions,) these have generally been considered as one muscle; and in such muscles, when the whole acts, it produces one general effect, as in the pectoralis major muscle. Also those muscles m which the origin and insertion are of considerable extent, and produce different motions of the same part, yet produce one general 240 HUNTER ON THE ANIMAL CECONOMY. effect when the whole acts, are considered as distinct muscles, as the trapezius, the broad muscles of the abdomen, &c. When a muscle has a number of insertions, and each portion moves a distinct joint, while the whole mass, in the same action, moves all these joints, it is then considered as only one muscle. Of this kind is the longissimus dorsi, the use of which is to erect the whole spine; but its particular action (if it had any) could only be to move one or more joints, according to the number of portions in action.

External Figure of Muscles.

Muscles have various shapes and sizes; they are long, short, thick, round, flat. They have the fibres either in straight lines or in curved ones; they may be broad and thin, or hollowed and circular, making rings; all which varieties of size and shape are connected with their actjon and use, and have induced anatomists to give them different names, as teres major, latissimus dorsi, longus colli, palmaris brevis, sphincter oris, &c, rhomboides, deltoides, pyramidalis, &c, &c. The form and size of muscles are adapted to the uses in which they are employed ; and these in general arise from the nature of the parts or joints to be moved. In some muscles the position of the whole leads to the general direction of all its fibres ; but this does not always happen, being the case only in muscles of a more simple construction. A muscle, for example, lies between the os hyoides and the upper end of the sternum, which two points lying nearly in the same plane would lead one to presuppose the fibres of such a muscle to be rectilineal, which is really the case. The figure of the muscle often shows the motion of the joint which it moves, particularly if it is a simple motion. This is the case in the rectilineal muscles and those which are nearly so, or those which are radiated, as the pectoralis, diaphragm, &c.

The different hinds of Muscles.

Muscles are more or less complex, arising generally from the different dispositions of their fibres, which difference is owing to the manner of their arising and being inserted, more particularly the former; and hence we say, muscles are straight, broad, radiated, half-penniform, complete-penniform, and complex. The most simple muscle would be one whose fibres are in the direction of its body, or in a straight line between the two resisting points, and should be called rectilineal; but there is not in the human body a muscle truly rectilineal, and from what has been observed of the disposition of the muscles and their tendons, also of their origins, it is hardly possible to have one. The straight muscles have fewer fibres in proportion to their size than the oblique, therefore their powers are less; some are CROONIAN LECTURES ON MUSCULAR MOTION. 241

round, or nearly so ; others are flat and broad: some of these last are radiated. The half-penniform muscle, although nearly as simple as any in the body, appears to be the first stage towards combination. It is composed of a series of fibres, arising from a bone, tendon, or fascia, but more commonly a tendon, of which the insertion runs nearly parallel to the origin, representing a quill with one side of the feathers taken off. This disposition of fibres, from the mode of origin or general disposition of the bones and fascia above described, is almost as common as any in the body. The complete-penniform muscle is two half-penniform muscles joined together. The complex-muscle is several complete-penniform muscles united into one. There are many half-penniform and complex muscles in the human body, but hardly one instance of a distinct complete-penniform muscle. In proportion to their combination their fibres are shorter, and a greater number in a given size, which must make them proportionally stronger.

Muscles which move bones, cartilages, &c, which are inflexible in themselves, generally lie upon them; for instance, the biceps flexor cubiti lies on the os humeri, the latissimus dorsi upon the back. Now the humerus and spine have little motion in themselves when these muscles have occasion to act. Muscles, however, lie sometimes upon the axis of motion, the body of the muscle going ovei the joint. This is most remarkable in parts near the centre of the body, as in the muscles of the spine, and in those of the first joints, or setting on of the extremities. The necessity of this disposition will appear more evident when we consider the vast power which must often be brought into a small space. In the spine, for example, there is not surface sufficient in this chain of small bones for the origin and insertion of a sufficient quantity of muscle ; therefore the fixed point ofthe most superficial muscles is removed to a distant and broader base, and they pass over several joints to their different insertions, as the longissimus dorsi, sacro-lumbalis, &c. The same disposition is necessary in the first joints of the extremities ; the extremities come out at once from the trunk, which is a broad or extended base for muscular attachment, so that the muscles are obliged to pass over the joint some way to find a surface for their insertion. Muscles in general lie in the direction of the parts they are to move; there are, however, exceptions to this where there is an irregularity in the motion of the joint, as in the motions ofthe head, shoulders, ribs, thighs, &c. 22 242 HUNTER ON THE ANIMAL CECONOMY. In those animals which have one great centre of motion, to which series of smaller ones are subordinate, as in man, the bodies ofthe muscles are in general nearer to the fixed point than to the moving one ; and'the muscular fibres often arise from the fixed point itself, without the interposition of a tendon; these muscles, however,do not come near to the moveable point, but are attached to it by a tendon, and frequently a very long one. This brings the body of the muscle, which is the heavy part, nearer to the centre or basis of the whole body, which is most able to support it; it also makes the part to be moved freer, more fit for motion, and better adapted for other purposes which may be required.

Tendons and Fascia, and their Uses.

In most machines constructed for motion by art, there is the machine itself, or all the different parts which are formed for motion, so disposed as to make one part when moved become the cause of motion in another, communicating it to every part of the machine; and the moving power is superadded, and is not to be considered as being a part of any such machine. A horse, for instance, cannot be considered as a part of any machine which he moves, although he is essential to its motion. This is also the case in many parts of the more perfect animals where great variety of motion was necessary, parts being constructed for the purpose of motion only, having no power within themselves, but this power is superadded or applied to them, as in the extremities of many animals; but there is no known animal somechanically constructed in all its parts as to have the power distinct from the parts to be acted upon in every part of its structure. There are in all animals parts constructed for motion which have the power of moving within themselves ; those in the more perfect animals are the heart, stomach, intestines, &c. In the more simple animals all the parts of the body are composed of materials with the power of motion, so that in them the machine and power are combined in one, as in the polypus, leech, worm, &c. In the parts of the compound animal constructed for motion each part is independent of another, so that one part may move, or have its motion complete, while all the other parts are at rest; but although the mechanical parts are so constructed as to have their motions independent, yet the simple effect is not always produced, for the powers are in many places so applied as for one power to move two, three, or more parts, as in the fingers. The same power has often a retrograde effect, moving the part which was its fixed point of motion. In an animal body the machine constructed for motion is composed of bones, cartilages, &c, and the unions of these form the places for motion, called joints. The construction of the bones at those parts which constitute the joints is only such as adapts them for motion on each other, not CROONIAN LECTURES ON MUSCULAR MOTION. 243

making them become themselves powers so as to move each other, as in the machines constructed by art. The bones and cartilages are confined or kept together by strong pliable substances called ligaments. There are also parts called tendons, which are the medium of union between the different parts of the machine and the powers. They have hitherto been considered as belonging to the powers; but I shall rather make them a part of the machine itself. A tendon is a peculiar substance, placed between some muscles or powers and the parts of the machine to be acted upon by such powers. It is composed of white fibres placed parallel to each other, forming a chord, which is extremely flexible, has no sensible elasticity, and is much smaller than the power to which it is attached. Its figure is in general a little rounded ; sometimes, however, rather flattened, and in many situations it is broad and thin; in all cases it is extended between the body to be moved and the power. It is sometimes spread out in breadth, and is then called fascia: this form answers various purposes. Its fibres in some situations run pretty parallel, but in general they are interwoven. It has flexibility, strength, and convenience in size. The application of this substance is extremely extensive, complicated, and various. The parts adapted to motion in animal bodies, as bones, tendons, &c, are formed with greater nicety, and fitted for more exact motions in the more perfect animals, of which we have a striking instance in the human subject. The purposes which this substance, called tendinous, answers in the animal machine, are the following: First, it intervenes between the body to be moved and the power, to keep up the exact proportion necessary between them to produce any determined motions, so that the length of the bones, or the distance between the joints or points of motion, the quantity of motion in the joint, and the quantity of contraction in the muscle, are proportioned to one another. But if this substance had been 'wanting, and the muscular fibres had extended the whole distance between many of those joints, the power of contraction in such a muscle would have been much too great, especially in the extremities.* The tendon is used for this purpose principally where

* [A most beautiful and forcible example of the use of tendon in limiting the length of a muscle to the extent of motion required to be produced in the part to be.moved occurs in the sterno-thyroidei ofthe giraffe. Had these muscles been continued fleshy as usual, from their origin, through the whole length of the neck, to their insertion, it is obvious that a great proportion of the muscular fibres would have been useless, because such a condition of the muscle would have been equal to have drawn down the larynx and os hyoides more than one third of the extent of the neck, which is neither required nor permitted by the mechanical attachments of the parts. The sterno thyroidei, therefore, proceed from the head of the sternum, blended together in one fleshy fasciculqs for about nine inches, and in a tendon which is continued for six inches ; this then divides and the muscles proceed again fleshy for about sixteen inches, when a second tendon intervenes 244 HUNTER ON THE ANIMAL CECONOMY. the fibres of the muscle run parallel to the direction of motion; for we shall find the tendons to which many muscles are attached longer than we could suppose necessary, from this reason singly. This, however, arises in them from the oblique manner in which the muscular fibres are placed, and the mode of their being attached to the tendon, as may be seen in the complete-penniform. Secondly, tendons and fascia are in many places substituted for bone, there not being a sufficient surface of bone for the attachment of all the muscles in an animal body ; and, by being much smaller and thinner, they exclude the necessity of bone. Thirdly, tendons and fascia, from their flexibility, answer in many parts better than bone; for if a long process or thin lamella of bone had united the ends of the muscles to the principal bones to be moved, no motion could have been produced by the endeavour of such muscles. In many situations, where flexibility is not required, they answer better than bone, from their yielding to external or internal pressure, which bone could not have done without being liable to be broken; as in those situations where they give attachment to two muscles, and where they cover many muscles, as in the forearm. The advantage arising from the flexibility of tendon and fascia is seen in its full extent by comparing the muscles of the more perfect animals with those of the oyster, lobster, or turtle, where many of them are attached to external shells, instead of fasciae. Flexibility also allows them to vary their direction, by which means they vary the motion of the parts, as in the tendon of the biceps flexor of the forearm winding round the head of the radius: the first action of the muscle (in some positions of the bone) gives it rotation upon its axis, the second bends it upon the os humeri. Similar actions are produced by the latissimus dorsi and teres major. Fourthly, fascia? from their strength answer in many situations better than bone, for a lamella of bone ofthe same thickness would in many cases have been broken by the contraction of the muscle to which it was attached. Fifthly, it was necessary that some substance should be introduced. as a medium between bones and muscles, to admit of the nicety of action and freedom of motion we find in many parts of the body, particularly in the fingers; which could not have taken place if the muscles had been continued from bone to bone. Where flexibility is not necessary, we find then that there is a continuation of bone, as in many birds, as in the leg of the turkey,

in each between the preceding and the next fleshy portion, which is finally inserted into the thyroid cartilage, and, by a continued fascia, into the os hyoideu; thus the quantity of contractile fibre is proportioned to the required extent of motion by intervening tendons; the sterno-hyoidei being wanting or their place supplied by the sterno-thyroidci, as in some other ruminants. ° The analogue of the omo-hyoideus is, in the same animal, adjusted to ils office I 8, ui' and um°re S'mPle modification ; its origin is removed from the shoulder-blade to the nearest point (the third cervical vertebra) from which it could act with the requisite force and extent upon the os hyoides.] CROONIAN LECTURES ON MUSCULAR MOTION. 245

partridge, &c, and through the whole body of most fishes; so that tendon is to be considered as a substitute for bone where that substance would be improper. Physiologists, however, have given a very different idea of it, supposing it to be a continuation and condensation of the muscular fibres; for which supposition there is no proof, even the smallest shadow of reason, either from analogy or from the parts themselves: it is therefore too absurd to deserve refutation. Besides the uses of fasciae above described, we find them in many parts of the body covering muscles, giving origin to them, binding down the belly of the muscle, and also binding down the tendon which is attached to it: this application of them is chiefly found in the extremities, particularly the forearm and leg. Where the fascia binds down the tendon at or near the joint it is called ' annular ligament,' which is in general little more than the fascia made strong; but where greater nicety in the motion of the parts is required we find annular bindings independent of the general fascia, as in the fingers and toes. These are to keep the tendons from having lateral motions, and where the joint makes an angle, to prevent their coming into straight lines, which would happen if not prevented by this annular ligament, and which would destroy the intention of the joint, as is evident in the fingers. Where the fascia covers two muscles it is fixed to the tendon which lies between them, and generally covers their tendons. Where it covers a tendon it almost surrounds it, making a kind of theca, and is fixed to the bone along which the tendon passes. These circumstances only take place where muscles are placed at a considerable distance from the parts to be moved, and their tendons pass over more joints than one, as in the muscles of the forearm and leg, where the tendons go to the fingers and toes. Fascia is sometimes very thin, called membrana communis musculorum, covering superficial muscles, particularly the broad ones, as theobliqui externi, latissimus dorsi, pectoralis, &c, and on some of the deeper-seated broad muscles, but thinner and looser in its connexion with the muscles. It is never met with in this state on the round muscles. It would seem to be intended to connect the skin by its cellular membrane more closely to the muscles, by which means the skin may be in some measure moved by them. The fascias in some instances give insertion to muscles, as in the thigh, and to the broad abdominal muscles.

Attachment of Muscles to Tendons.

As the body of a muscle is much thicker than the tendon to which it is attached, the fibres of the one cannot be continued to the other in a straight line; therefore the end of the tendon is not joined to that of the muscle in one line, but by a tapering point or an irregular edge, to gain surface for the insertion of the muscular 22* 246 HUNTER ON THE ANIMAL CECONOMY. fibres, the oblique ending of a small body being capable of becoming equal to the less oblique ending of a thick one; but the direction of the tendon cannot be the same with the muscular fibres, but must be more or less oblique, so that an angle must be formed at their union, the muscular fibres being bent a little in towards the tendinous ones. This obliquity in the direction of most of the muscular fibres, and of their attachments at both ends when they have tendons at both origin and insertion, makes the muscle become gradually thicker from the body of the first tendon to the most distant point of that tendon; and if the middle part of the muscle is free from tendon, that part will be everywhere equal in size, or if the tendon at its insertion goes higher than at its origin, the part where these tendons are opposite and parallel to one another will also be equal in size, the body of the muscle from that part becoming gradually smaller upwards towards its origin, and downwards towards its insertion. From such disposition of fibres the bodies of most muscles are much longer than their component fibres, which produces in the same proportion a shorter complete tendon. This circumstance lessens the thickness of the bodies of such muscles, and also of their extremities, which gives to the muscle a curve in its outer line. The obliquity in the direction ofthe muscular fibres admits of there being a greater number, and lengthens the swell in the time of contraction, by which means the motion of the muscles in the cellular membrane becomes more free, the swell is smaller, and the smoothness of the whole body is preserved. The tendon at its origin is generally on one side, or surrounding the muscle, and the inserting tendon is on the opposite side, or next the centre of motion.

Oiigin and Insertion of Muscles.

In describing the origin and insertion of muscles the tendons are always included, and this is very necessary to be understood ofthe insertion, as it is the point of insertion which in some degree gives the use of the muscle. The origin of a muscle is in general the most fixed point, and the insertion the point where the greatest motion is produced ; in different muscles, however, these points are subject to variations, and on different occasions in the.same muscle, most of them being capable of acting from either end. Some of these variations may be considered as natural, and others as a force upon Nature. I shall call the variations natural where the effect is necessary in the natural movements of any part of the body, such as the extensors of the thigh, the glutaei, particularly the gluteus major, are commonly understood to produce; for these muscles, in the action of walking, when the leg is brought forwards or bent by the flexors, extend the body upon the thigh, by which action the body is brought CROONIAN LECTURES ON MUSCULAR MOTION. 247

forwards before and over the foot; also, after stooping or bending the body forwards, the glutasus muscle raises it; and these are as much the actions of this muscle as bringing the leg and thigh back upon the body. Some muscles are capable of performing similar inverted actions, although not commonly so employed as the recti abdominis, whose ordinary use is to bend the body upon the pelvis, but which sometimes, however, bend the pelvis upon the body. Those which I call a force upon the natural effect ofthe muscle, or an inversion.of the fixed point, are where the moving point is by art, or something foreign to the body made the fixed one, as the hand ; and the action of the muscles, instead of bringing the hand to the body, draws the body to the hand. In many animals, however, the effects of certain muscles are reciprocal, and these, therefore, cannot be said to have an origin and insertion, both the parts to which they are attached being equally moveable in themselves, and there being no power capable of keeping either the one or the other firm, as is very evident in animals where the two points of attachment, or parts to be moved, are similar or in pairs, as in the bivalve shell, where the motion in the two valves is equal. The origins of muscles are in general more simple than their insertions, nothing being wanted but a sufficient surface for attachment, which is generally required to be pretty extensive; and for this purpose there are various contrivances, which have given rise to particular names, for the various kinds of origins. The origin of a muscle is generally from an immoveable part with respect to the action of that muscle, and commonly from the most firm or solid parts ofthe body, as bones, cartilages, periosteum, tendons, and fascia; some muscles, however, arise from soft parts, as the lingualis, orbicularis oris, &c. The insertions of muscles are less simple, for as the insertion is to produce the various motions of the parts, and, as the construction for motion is hardly the same in any two joints, more nicety and art is required ; the insertions of muscles are commonly more determined than the origins. Few muscles are so situated as to arise from surfaces at right angles to the direction of their fibres, as they generally pass nearly in the same direction with the surface from which they arise, whether bone, tendon, or fascia. They, therefore, take their origin from a part as they pass along it, which renders it very oblique, and produces the form of muscle called half-penniform. Some muscles, however, both arise from, and are inserted into, surfaces at right angles to the direction of their fibres, as many of the spine, &c. The insertions of muscles are more general than their origins, for they must be inserted into every part of the body to be moved, and therefore we find them inserted into bones, cartilages, periosteum, tendons, fascia, and many of them into soft parts, as the skin, cellular membrane, the tongue, &c. 248 HUNTER ON THE ANIMAL CECONOMY. In describing muscles, they are never said to be inserted into, or to arise from, periosteum, but from the bone the periosteum covers, as it is upon the bone the effect is produced. Muscles never arise from, or are inserted into, capsular ligaments, for although in some few cases they seem to run into, or are attached to them, the effect is not immediately on the capsular ligament, but on the bone beyond it, and the ligament is strengthened at this part in proportion to the power of the muscle; so that in this case, as far as regards the mechanical effect, the ligament and tendon may be considered as one. Many tendons, in their course over joints, adhere to the ligaments, and bring them along with them in the action of their muscles. This adhesion, however, is only to bring out a secondary use, to save the ligament from being bruised between the bones, which otherwise might have been the case. Many muscles besides these insertions give off fibres to the fasciae, which cover other muscles, as is evident from the lower edge ofthe pectoralis major, biceps flexor cubiti, semitendinosus, &c, but what is intended by it is difficult to determine. The origins of muscles are generally further from the centre of motion ofthe part to be moved than the insertion; remarkable instances of this are seen in the biceps flexor and triceps extensor of the forearm, and all the movers of the hand and fingers. This gives neatness to the parts to be moved ; but its principal use is to give velocity to the motion, with a small quantity of contraction; what it gains, however, in velocity, it loses in strength. That velocity is the intention is evident, for if the muscular fibres had been continued to the most distant end of the bone to be moved, the muscle must have been longer, and must have contracted more, to produce the same effect, which contraction must have taken a greater length of time.* Many muscles arise near to the centre of motion of the part to be moved, and are inserted at a considerable distance, as the deltoides. This also produces a great deal of motion in the part to be moved, with very little contraction of the muscle; for when the greatest quantity of motion is produced, the insertion has approached very little nearer the origin. This kind of insertion gives an advantage to the power of the muscle, which the other has not, viz., a much longer lever, and allows the muscles to communicate their strength to the moving parts more fully, although with less velocity; and being employed upon parts of considerable extent, as the arm and leg, and generally upon the first joints of them, the effects upon the hand and foot are very considerable. In the formation of many parts of the body neatness is a principal object, as is visible, not only in the external form ofthe limb, but in the parts constructed for motion ; as in the formation of the * [The extent of the space through which the bone is moved is also greatly increased by this arrangement, in comparison with the extent to which the muscle itself contracts.] CROONIAN LECTURES ON MUSCULAR MOTION. 249

bones, and their situation with respect to one another, and the mode of removing the inserted tendon (when too close to the centre of motion to produce a sufficient effect) a little further off, by means of little moveable bones called patellae or sesamoid bones, as in the knee, first joints of the thumb, and great toe : and where this construction would be clumsy and inconvenient, as in the fingers and lesser toes, the two tendons which are obliged to pass along these parts to their insertions at the second and third joints, are so disposed in their course, that the profundus, or one nearest to the bone, acts as a patella to the other, keeping it at a distance from the centre of motion equal to its own thickness; and the sublimis or upper one is obliged to split into two near its termination before it can be inserted into the second bone. The advantage gained by this construction is, that the tendon of the muscle employed in the greatest action is removed further from the centre of motion than it otherwise could be, and from which the other sustains no disadvantage.

Adaptation of Muscles to Joints.

It is to be understood that the joints of an animal are fitted for motion, and that their form, with the application of the muscle or power, are, in a natural state, so adapted to each other that the power acts with the greatest advantage, and that any variation from the natural form or position of the joint weakens the effect of the power. This may be demonstrated in those who turn out their toes, as in a dancing-master, who, before he makes a leap, turns his toes forwards. Few joints in an animal body are confined to one motion, therefore either a number of single muscles must be employed, or the direction of the muscular fibres, of the tendons, and of the insertions, must be so disposed that a few muscles may produce the different effects. Joints admitting of motion in only one direction come nearest to a simple joint: the joint of the elbow is perhaps as near this as any in most animals, as also the joint of the lower jaw in the carniverous animals, and the fingers in most animals:* the muscles of such joints are tolerably simple in their structure, direction, and insertion. In the joints which admit of various or compound motions, the construction ofthe muscle, the course of its different fibres, the disposition of the tendon in its course and insertion, produce a great variety of effects. This, indeed, was absolutely necessary in a number of animals, more especially those which have extremities, and particularly the human subject, in which there are more motions produced than separate muscles to perform them; nor was it possible, in the present construction of bones, &c, to have placed particular muscles

* [In insects and Crustacea every joint of the extremities, save that which is between the limb and the body, is ginglymoid, and limited to motion in one plane.] 250 HUNTER ON THE ANIMAL CECONOMY. so as to perform all the motions, without interfering in the opposite actions. In the human subject the number of muscles exceeds that of any other animal; the motions in the joints, however, are still greater than can be accounted for by the increase in number of muscles, ihe difference in the construction of the muscles, as well as of the joints, producing this difference, which is so remarkable in the joint of the shoulder, the rotatory motion in the forearm, and the joint of the thigh. Instances of the different motions produced by the shape of muscles, their mode of application, and the disposal of tendons, are seen in the biceps flexor cubiti, latissimus dorsi, &c, passing some way round the bones into which they are inserted, so as to produce two very different motions in the parts; at one time they may move the part through some space, at another time upon its own axis. The muscles in the lower jaw in graminivorous animals give a remarkable instance of this, there being hardly any of them which do not perform more than one motion. The disposition of tendons will often give a different direction to the body moved from that of the muscle, arising from the tendon bending over some fixed point and taking another direction, which is beautifully illustrated in the trochlearis muscle of the eye, the body of it passing in the same direction as the straight muscle of the eyeball, while from the course of its tendon it counteracts the oblique, which passes in a different direction. The obturator internus of the thigh and circumflexus palati are both of this kind. The different positions of tendons shall make two muscles produce the same effect in different ways, being inserted in the opposite sides of the same joint. The gastrocnemius, which is inserted into the heel behind the joint of the foot, pulls the heel up, which depresses the toes. The tibialis posticus and peronei muscles, which pass in the same direction, and are inserted before the joint of the foot by means of their tendon passing round the joint, also pull the toes down, which raises the heel. Muscles, by the course and mode of insertion of their tendons, shall perform very differently a series of regular motions, bending some joints and extending others. Such are the uses of the lumbricales and interossei interni upon the fingers and toes: for their course is before the centre of motion in the first joint, but by winding round the second bone they get upon the back of the fingers and extend the two last joints. These, by their situation and insertion, produce an effect which could not be performed by the other flexors or extensors of the same parts. From the various formations of joints, and the different positions and insertions of the muscles or powers, the greatest force of the power is required at different periods of the motion. In all those where the power is between the centre of motion and the resistance, the greatest action of the muscle is required at the beginning, as a smaller contraction of the muscle produces a greater effect at this time than afterwards, as in the deltoid. Where the power and weight are at the two ends and the fulcrum CROONIAN LECTURES ON MUSCULAR MOTION. 251

in the middle, as in the biceps extensor of the arm, or where the power and the fulcrum are at the two ends and the weight in the middle, as in the muscles of the tendo Achillis, the greatest force is required in the last part ofthe motion. Where there is no lever, but one body moving round a centre as a pulley, which is the case in the extensors of the knee-joint, the same force is required through the whole of the motion. We may observe that the ligaments of the joints are necessarily so constructed and placed with respect to their motion as to produce an effect analogous to that of a centre-pin in a plain circular joint, in all the various situations of the centre of motion. There are few levers of the first kind in the body, on account of the unevenness in the effects of muscular contraction upon them, arising from the variation taking place in the angle of insertion of the muscle; they are therefore introduced where that is compensated by some other circumstance in the action. The motion of the body upon the thigh is a lever of this kind, and is generally used in raising the body; but as the body becomes more and more bent it requires less power to overcome the power of gravity in the body, therefore the angle of insertion is becoming more and more in the same plane with the moving part. The same thing takes place in moving the heel. The angle of insertion can only have its effects vary when the insertion is some way from the centre of motion, and this only when in levers. When in levers of the first kind (which extend joints) the effect is gradually becoming less; as, for instance, the extensors of the forearm, which are inserted into the olecranon, because the angle is becoming less and less; but perhaps the velocity which the parts may commonly acquire make up this loss. When inserted into levers ofthe second kind they are gaining in their effect, the angle becoming greater, as in the flexors of the forearm. In the lever of the first kind the quantity of effect, according to the quantity of contraction, is becoming more and more as the angle becomes less. In the second it is becoming less -and less as the angle becomes greater.

Muscles going over more Joints than one. Many muscles, or their tendons, go over two joints while they only move one, and the joint which they do not move is often moving in a contrary direction, from the action of another muscle; this happens in the biceps flexor and extensor of the forearm, the flexors of the leg, &c. This disposition saves a great deal of muscular contraction; for by the biceps going over two joints while it is employed in bending the forearm upon the arm, the arm is bending back upon the scapula, which last action would produce in some degree a flexion of the forearm, even if the biceps flexor did not contract at all, but only remained without relaxing. This arises from the motion of these joints going zigzag to one another. Muscles whose tendons pass over two joints keep the joint not to 252 HUNTER ON THE ANIMAL CECONOMY. be moved, firm; which is of great service, as when we bend the forearm by the biceps flexor, the two heads rising from the scapula, especially the long head which runs through the joint, keeps the joint of the shoulder firm. In this motion there are muscles acting on both sides of the joint. Had it not been for this purpose, the biceps flexor might as well have arisen from the head of the os humeri. Muscles often go over two, three, or four joints, and only move the third and fourth, as the flexors of the last joints of the fingers; but to prevent the first and second joints being moved by this action, the extensors ofthe intermediate joints are obliged to interfere and keep them from bending. Every joint has a certain quantity of motion, and the quantity of contraction of the muscles of that joint are adapted to that motion: we Have therefore in joints of considerable motion long muscles, as those of the knee, and in joints with little motion we have short muscles, as those of the spine.

Ofthe Strength of the Body as compounded. The strength of a part and the strength ofthe whole body is in proportion to the natural resistance, which arises either from some body to be propelled, as the blood, urine, &c, or from the position of our bodies, to overcome gravitation; for every muscle in the body is just able to move the part to which it is fixed with tolerable ease in the most difficult position, and any additional weight in that position will fatigue it, it being unable to support it any time. From this it would appear that the different parts of our bodies arc not much stronger than can support their own motions with ease; and whatever motion the body can perform with ease, by exerting itself it can give it a considerable velocity, or support a greater weight for a continuance. If our muscles are capable of moving our bodies in every position, they must be able to move much more in some positions than others. If I can raise my body from the ground perpendicularly up when my feet are fixed upon the ground and my knees bent at right angles, I can support or raise a much greater weight when upright or nearly so. If a horse raise himself from the ground when his legs are bent, he can support a greater weight when erect or standing; and if loaded with no more than he can stand under upon three feet, he can walk with it. A leg also that can raise the quarter of a horse from the ground can move the parts of which it is constructed only with great velocity. If you load a man with no more than he can stand under upon one foot, he can walk with the load. A man can raise his whole body upon his hands, and therefore can move his hands with great velocity when they are put into motion without the body.

The Effects arising from the different Constructions of Muscles. The straight narrow muscle, whose fibres run parallel, generally CROONIAN LECTURES ON MUSCULAR MOTION. 253 employs all its fibres, so that when it acts, the whole muscle is in action at the same time. The broad and radiated muscles do not always employ the whole of their fibres at the same time, each part often acting separately, like separate muscles; they are capable of taking on an action at any one part, and of continuing "from that part a succession of actions to any other part, or through the whole muscle; and they are capable, by an action of the whole muscle, of producing one general effect. The action of the lateral portions of such muscles affects the tendon somewhat similar to the complete-penniform; therefore the middle fibres must either be longer than the lateral, or have a great power of contraction, which will be better understoood after the explanation of the action of the complete-penniform. The temporal muscle is an exception to the rule of muscles being made radiated to produce a succession of actions; for whatever part of this muscle acts, nearly the same effect is produced ; such muscles, cceteris paribus, produce effects proportioned to their length of fibres. These muscles have one advantage, which is, that their fibres are much longer than those of any other muscle whose body is of an equal length; they can therefore contract much more, and are always used in the more extensive motions. The half-penniform muscle is, I believe, similar in its action to the foregoing; for although the fibres are more oblique, the tendon is moveable laterally, so as to move nearly in the same line with the fibres. This kind of muscle is never used in extensive motions, except where there is considerable distance between the origin and insertion, to admit of sufficient length of fibres. Although there is hardly an instance of a complete-penniform muscle in the body, yet as all the complex penniform act upon the same principle, I shall explain the effects in a supposed complete-penniform, and show that this disposition of fibres produces a greater effect than any of the foregoing. In the action of these muscles we suppose that the inserted tendon is always moved in the middle line, between the two origins of the muscle, and therefore the muscular fibres in this action do not lose their obliquity, as in the half-penniform, but have it increased, which produces a greater effect. Let A C and B C represent two fibres of a penniform muscle in their extended state, A and B being their origin, and C the point of insertion into the tendon O V. 23 D 254 HUNTER ON THE ANIMAL CECONOMY. Suppose these fibres contracted to the points E and F, it is evident that such contraction will bring the point of insertion from C to G, and that the motion of the tendon will be to the contraction ofthe muscle as C G is to C F or C E ; for A G is equal to A E, and B G equal to B F, or A and B are the centres of the circles AGE and B G F. The advantage arising form this construction of muscle is great, as it ajlows of a great number of fibres in small bulk, and is therefore used where strength is required. It is also used where the quantity of motion required is greater than the distance between the origin and insertion would admit of in any other construction of muscle. 22. CROONIAN LECTURE ON MUSCULAR MOTION, No. III.

[Read before the Royal Society in the year 1779, by John Hunter, F.R.S.]

Ofthe Effects of Muscles.

In the spring of 1776 I had the honour of delivering to this Society the Croonian Lecture upon the self-moving power in animals seated1 in the muscles, in which I also made some observations on the analogy between this power in animals and a similar power in vegetables. I was then desired to prosecute this subject, and accordingly, in the winter following, T presented a paper, in which I considered the most remarkable circumstances relative to this power in animals, through which they are enabled to perform all their various motions,—such as the arrangement of the fibres in the construction of all the muscles; the distinct muscles, their figure, kinds, and situation; the tendons, and fasciae, with their uses; the applications of muscles to tendons, their origin and insertion, and the fitness of them to the joints. It was here noticed that their effect in some cases is equal to their quantity of contraction ; in others not. The different quantity of contraction in the same length of fibres in different muscles was observed, and the effect arising from the diflerent construction of muscles. As the muscles are, by their contraction, the cause, either immediate or remote, of every action in the animal, and as animals are so constructed as to produce evident mechanical effects, arising from an application or combination of the mechanical powers (the contraction of the muscles being the power or original cause), I shall now consider this mechanical application and its effects, with which I shall slightly compare the applications and effects of the mechanical powers as applied in machines which aje the productions of art. Muscles are the first simple powers in an animal, by which all CROONIAN LECTURES ON MUSCULAR MOTION. 255

the mechanical effects are ultimately produced ; but an animal body is very differently constructed from that of a machine. A machine is composed of a series of parts, having a regular dependence on each other; and the power which produces motion is applied only at one end of these parts, although two, three, or more effects may ultimately be produced, which effects, notwithstanding, must therefore arise from the multiplication of the parts ofthe machine, and not from the increased number of powers. But an animal is composed of parts, each part, and each motion of each part, having its own moving power, capable of producing its immediate and remote effects independent of each other; so that in animals many effects may be going on at one and the same time, and each actuated by its own peculiar power, by which means an innumerable variety of effects arc carried on at the same time, and without the least confusion or interference with each other. A muscle, as to itself, may be considered in two lights, one respecting its quantity of contraction, and the other its power, both of which produce considerable effects in the body, and each is employed according to circumstances. Every muscle in an animal body may be considered as a simple independent power; and if we attend to the effects that many animals are capable of producing, particularly the motion of fishes and the flight of birds, we shall see great reason to admire the immense velocity and great force with which their muscles are contracted; and if we compare the effects produced by the contraction of their muscles with the weight of each muscle and the part which is to move, it may lead us to conclude that there probably is not in nature a more active simple power than the contraction of the animal muscles. An animal is perhaps the only machine that has the power of overcoming its own gravity. In considering animal bodies in general in a mechanical light, we should first attend to the most simple mode of action in the animal, or the mode of action of the muscles in the most simple animal, and proceed from the most simple to the most compound or complicated, in which latter may be discovered applications and combinations ofthe several mechanical powers (which for beauty, simplicity, regularity, and aptness far excel all human applications), in order to produce the manifold effects of animal motion, and to accommodate the ultimate velocity or force at the same time to the particular effects to be produced, as well as to the simple power of contraction in the several muscles which act as first movers in producing that effect. In many animals the parts endowed with the first principles of motion, viz., the muscular fibres, are themselves formed in various shapes, so as to constitute complete animals of the most simple fibres; and even in the most complicated animal many distinct parts are composed of those moving powers, forming regular 256 HUNTER ON THE ANIMAL CECONOMY. bodies, called organs, commonly producing of themselves a vast variety of effects, by which means many of the numberless internal actions respecting the animal ceconomy are carried on; so that even in those more complicated animals we have the first organization formed of muscular fibres alone, in the same manner as in the more simple animals.* This would lead us to consider the effects of muscular contraction in very different views, viz., according to the various effects they are capable of producing in animals of all the various constructions and complications. In many of the more simple animals there is little else besides those formations or organizations composed of muscles. , A polypus is little more than a muscular bag, and by the contraction of its fibres in different parts, and in different directions at different times, the bag is changed into various forms and sizes. A worm seems a little more complicated: however it is in reality little more than a body formed of different parts, each of which is composed of muscle. A slug, a maggot, as also numberless tribes of sea-animals, come under the same description. But as animals emerge from this simplicity of construction, becoming more and more complicated, having particular parts added, and those parts being composed of something besides muscle, and it also being necessary that these should move, and be so constructed as to direct, circumscribe, increase, or limit the motion, we find the muscular fibres of such animals collected into various portions and forms, in order to give all the different motions to these superadded parts which were taken notice of in the former lecture. Those additional parts are composed of more rigid matter than muscle, viz., bones, cartilages, &c, on which the muscles can have no other influence than by giving them motion. There are a number of those bones, cartilages, &c, in many animals, some having more, some fewer; and they are connected in such a way as to form between them intervals fit for motion, called joints: in most parts of the body there is a series of those bones and joints, as the spine, the extremities, &c. Many of these bones are so formed, and so placed and connected with one another, as to form levers (and those of all the various kinds), which direct and limit the motions, so as to produce a regularity in the whole. As the relative inclinations and positions of those several bones which are immediately connected and joined together are very various, it follows that there must be a variety in the angle of in-

* [Hunter here compares the first-formed parts of the vertebrate embryo, derived from the mutually receding layers of the germinal membrane and the folding of those layers, with the simple homogeneous tissue of the hydra or other acnte animal. And, as he applies the term muscular to the contractile tissue of these animals, so he would also regard the homogeneous gelatinous parietes of the newly formed digestive sac ofthe embryo of the higher organized species as being in like manner endowed with contractility, and therefore ' formed of muscular fibres, or contractile substance ' alone.' CROONIAN LECTURES ON MUSCULAR MOTION. 257

sertion ofthe several muscles, to accommodate them to the particular circumstance of each joint. And as those inclinations vary in the motions of the joint, so must the angle of insertion of the muscles which will produce a difference in the effects, both in the power and quantity of contraction. To this great variety of these levers and joints we have the muscles adapted. We may observe, that the more perfect the animal is, the more curiously these levers and joints are formed, the joints commonly consisting of compound curves (which is the most remarkable in the more perfect animals), by which means their own motions admit of greater variety. . The human subject is a striking instance of this, having the joints more compounded, and the motions less limited, than in any other animal that I know, which circumstances require a greater variety of muscle, and the greater nicety in the adapting of each muscle to produce its peculiar motion. In the most perfect animals there are very few joints whose motion is simple,'or which are confined on all occasions to move in one direction; for whatever may be their chief or ordinary motion, in many there is some other motion compounded with it; nor are there many joints which move upon one centre in all their motions, but they shift their centre as the curve varies.* These firm inflexible substances are kept together by soft, yielding yet sufficiently strong parts, called ligaments, which are necessarily so constructed and placed, with respect to the motion of the joint, as to produce an effect analogous to that of a, centre pin in a plain circular joint, and in all the various situations ofthe centres of motion. I may be allowed to observe, previous to entering upon th mechanical motions produced by the muscles in an animal body, that, without external resistance, there would be no such thing as progressive motion in an animal; for although a muscle has the power of contraction in itself, and is capable of moving all its different parts upon itself, yet it cannot move any other part without having some fixed point to act from, which is the greatest point of resistance. There is in every animal, therefore, a fixed point from which the parts of the body take their principal motions. In the human body this fixed point seems to be in the joints of the thighbones; which point, being in the middle ofthe body, must be common to the extremities. We see, therefore, that the body either moves on the legs, or that the legs move on the body or trunk. Besides this, there are many fixed points, so that the body is to he looked upon as a chain of joints whose general centre of motion is in the joints of the thighs; but each has its fulcrum, or centre of motion, which is always on that side next to the first, or the general

* A remarkable instance of this we have in the joint of the lower jaw in graminivorous animals. 23* 258 HUNTER ON THE ANIMAL CECONOMY. centre of motion ofthe whole, by which means the smaller moves upon the greater, the toe upon the foot, the foot upon the leg, the leg upon the thigh, and the thigh upon the body. The same in the arms, the wings of birds, the tails of fishes, the oars of a boat, &c. But those motions can be, and often are, inverted, so that the greater can be made to move upon the smaller; as, for instance, the body upon the thigh, the thigh upon the leg; or, in birds, the body upon the wing, &c.; but then the smaller must be so circumstanced as to be the fixed point, which cannot be without external resistance. It is the inverted motions, then, which produce the progressive; but it is necessary, for the production of a succession of them, to bring in also the motion of smaller parts upon greater; the two kinds of motion are, therefore, acting alternately whenever the progressive motion is continued beyond the first action. The animals which move upon the earth have it for their point of resistance. Birds are supported and propelled in their flight by the resistance of the air ; and fishes, like boats, by the resistance of the water. The effects of muscular contraction may be divided into three kinds. The first is, where the effects are in those parts of the body which are principally composed of muscle : these simply vary their configuration without extending their power beyond themselves, as in the actions of many ofthe more imperfect tribes of animals, as the leech, polypus, &c, and in many parts of the more perfect animals, as the heart, stomach, intestines, bladder, and all the vascular system.* The second is where the effect is more extended and reaches beyond the muscles themselves to such adjoining parts as are either formed simply for motion, as bones, cartilages, &c, or whole parts of the body, such as an eye, a lip, the skin, &c. The third is where the effects are mixed, viz., partake of both the preceding, as in those produced by the muscles of the tongue, of respiration, of the abdomen, &c, where they both move parts and alter their configuration. The first and third kind of effects of muscles, when considered in the more perfect animals, are more connected with the internal ceconomy of the animal than with the mechanical application of the power of muscular contraction ; therefore in them it is the second which comes properly under consideration, as mechanical, since it produces visible mechanical effects upon parts formed for motion, and evidently calculated to vary the velocity from that of the first. The application of muscles in an animal body is either to produce a quantity of motion equal to the quantity of contraction of the muscle; or, by the application of levers, to give a greater * [This is not exactly true of these viscera, for their contents ejected by the contraction of the surrounding fibres act upon the parts into which they are propelled, as the bone moved by the muscle inserted into it also carries the part connected with it along with it in its motions.] CROONIAN LECTURES ON MUSCULAR MOTION. 259

motion than could be produced by the simple contraction of the muscle. This in general is not the case in machines composed by art; for in art the principal reason for the introduction of mechanics is to acquire power in the effect, which obliges us to increase the velocity in the moving cause, as in levers and pulleys. However, this is not universal in machines ; for some have it reversed, as the catapulta, the lock of a gun, and also in many machines where strength is not the object, but velocity in some particular movements, as in watches, jacks, &c. Whether the effect of a given quantity of contraction in a muscle be or be not equal to that quantity depends upon the construction and disposition of the parts to be moved, or the form which the whole muscle is thrown into. Thus the effects of some muscles upon the parts are just equal to the contraction of the muscular fibres; such are those which simply draw parts to them, not varying the position of the part moved from the right line, as many of the muscles of the larynx, the trapezius, rhomboideus, and all of the panniculus carnosus kind, as the muscles of the face, platysma myoides, and the muscles of the skin of animals. Another class, whose effects are always known, or are the same in all cases, are those muscles which produce their effects from the shape which the muscle is thrown into, for instance, a curve. Curved muscles are of two kinds, viz., those which are fixed at their ends, as the abdominal muscles, pharynx, &c, and those which are circular, as the sphincters, heart, and the whole vascular system. These muscles always reduce the circumference and, of course, the diameter ofthe circle, which they themselves compose, in proportion to their quantity of contraction; but the ultimate effect here is not in proportion to the quantity of contraction, but decreases as the squares of the diameters of such vessels. But most parts of the body are so mechanically formed, acting as levers, and the muscles so advantageously inserted, as to produce a much greater degree of velocity in the motion ofthe part than is equal to the contraction of the muscle. But those mechanical applications are so various that there are no two muscles which act with the same advantages, excepting those that are in pairs. On this application of muscles to levers depends the distinction between the absolute and apparent force of muscles, neither of which can possibly be ascertained with any degree of certainty. Every muscular fibre is capable of contracting with a given power,"which power simply must be always its absolute force; but from the construction of parts to be moved, and the application of muscles to those parts, either an increased or decreased effect is produced. It is impossible to ascertain the absolute force of a muscle because there is no one known muscle in the body that we can throw into action separately, and independently of the collateral effects of others. And, if we could, there are many whose power could not be measured by any given quantity of resistance to be 260 HUNTER ON THE ANIMAL CECONOMY. overcome, so as to ascertain the power of contraction of that muscle, as, e. g., all those which simply pull bodies in a straight line : but, in those muscles which act upon the bones in the form of levers, if any could be made to act singly its power could easily be known. But whatever this power is it must be always the same; nothing can alter it excepting real weakness in the muscular fibres themselves. As we cannot separate and ascertain the absolute force of a single muscle, so it is impossible to find out the apparent force; and exactly for the same reasons that we cannot find out the absolute. The apparent force of circular muscles will be in a ratio proportionably to their diameters, and in those which are inserted into levers it will always be as the distance of the insertion ofthe muscle from the centre of motion, the angle of insertion, &c. But the relative force is not always the same, or it does not always act alone in the motion of the parts, for it is often joined with velocity, and then it may become vastly greater. But if not joined with velocity it will always be less than the absolute, as the length of lever in the resisting power is longer than in the acting one. The absolute force of a muscle will always be employed in the most simple action of the parts. The most simple action will be where a muscle passes in a straight line from some fixed point to a moveable one, and by its contraction simply pulls the moveable one towards the immoveable one, such as many of the muscles of the os hyoides, and in many other parts ofthe body. As the circular muscles are commonly employed in propelling bodies, and principally fluids, they will keep up an equal power upon the body to be expelled; for, the power increasing as the fluid decreases, it is capable of throwing out the same quantity in the same time.* I observed that the muscles, as moving powers in an animal, differ from the moving powers in a machine, the production of art, inasmuch as every part had its power adapted to the motion it is capable of, and therefore the motion of any one part did not depend entirely upon its own configuration and connexion with some other. Although this is in a great measure the truth, yet the motion in most parts is assisted by actions or the contrary in other parts, so that there is a kind of dependence and mutual assistance through the whole. This does not, however, arise from any mechanical construction, but from a connexion of the living principle in the powers of one part with those of another, which may be termed a species of intelligence. The motion of parts generally is the motion of a smaller upon a greater, and the greater becomes the fixed point upon which the * It may be asked, at what point of the contraction of a muscle has it the greatest power 1 Or, does it contract with the same force through the whole contraction 1 CROONIAN LECTURES ON MUSCULAR MOTION. 261

smaller may be said to move; but we find that there are few motions, however trifling, but what affect the greater part; therefore that this motion in the smaller part may be more effectual and answer the intended purpose, the greater part is either thrown into a counter-motion by its own muscles, or it is supported in its place by them, or it is thrown into the same action with the small part, so as to increase it. Hence the actions of these powers may be said to be of two kinds, immediate and secondary. The first is that which produces the immediate action of the part; the second produces the assistant, supporting, regulating actions, &c. For instance, when a man walks, it at first might appear that the only thing necessary to produce the ultimate effect was the motion of the two legs, the body being first thrown sufficiently forwards, so as always to require that motion of the legs to support the centre of gravity. But this is not sufficient; it is necessary that the muscles of the trunk should act, and regulate the body so as to support the centre of gravity on all sides. If the right leg moves, the muscles of the left side of the trunk act to support the whole on the left leg, and vice versd; so that the body plays upon the motion of the legs, by which means the legs have much less to do, and therefore can support it longer. In many of the actions of parts of the body other parts are kept immoveable, although they would appear to have nothing to do with any such actions. A man never performs any considerable action, even with any of the extremities, without the trunk being more or less affected, so as to favour the motion of the extremity. We find that we first make a full inspiration and that all the muscles of respiration act, also the muscles of the glottis, and of the soft palate, so as to confine the air which makes the trunk as rigid and firm as possible to support or sustain the actions and motion of the extremity. If an action takes place in an extremity, where a considerable effect is to be produced, which can only be produced by a considerable velocity, then the whole body gives it assistance so far as it is possible for it to do. If a man throws a stone, or a blacksmith swings his sledgehammer, the whole body humours the action, and the fixed point is thrown to a greater distance than the setting-on of the arm : the whole moves from the loins, or perhaps lower. Those secondary actions are brought in as auxiliaries, and answer two very important purposes: they increase the quantity of action when necessary, and they assist in easing the immediate action, so as to allow of a continuance of it, by which means animals are capable of performing greater actions, with more ease, and a longer continuance. Muscles regulate the actions of others not only by their contraction but by their relaxation, which last is a kind of negative aclion. When a man walks I have already observed that there are many muscles acting as secondary agents in the body, so as to assist the 262 HUNTER ON THE ANIMAL CECONOMY. immediate motions ofthe part to be moved; but, besides this, there are many ofthe same muscles that are gradually relaxing, so as to allow the alternate motions by imperceptible degrees to creep regularly into one another. Perhaps I cannot give a more striking idea of those primary and secondary actions, with the relaxations, which I have called negative actions, than to present to the minds of those who have some knowledge of the subject what must be going on with the muscles of a man balancing himself on a slack or tight rope, when the first or immediate order of muscles are acting with their utmost force; where the secondary are assisting in the secondary actions of the body, and as it were playing into the hands of the first; where others again are relaxing in proportion as the first and second are acting ; and where the entirely relaxed are waiting the opportunity to act, when called upon by any change that shall take place in the position ofthe body, which in such circumstances is in a continued agitation. 23. CROONIAN LECTURE ON MUSCULAR MOTION, No. IV.

[The manuscript of this Lecture appears not to have been among those which were accessible to Mr. Clift, and from his copies of which the Lectures in the present volume have, with his permission, been printed. Its absence may, however, be accounted for, from the fact that the substance of the Fourth Croonian Lecture was incorporated by Hunter in his work 'On the Blood,' (see the Chapter , on the Vascular System,) as is evident from the Abstract of the ; Lecture in the Archives of the Royal Society, the subjoined copy of which Abstract Mr. Palmer, with the permission of the President and Council, has obtained for the use of the present edition of Hunter's Works.]

[The Croonian Lecture on Muscular Motion, by Mr. John Hunter, was read on the ,.' 25th of May and 1st of June, 1780.]

^The construction and general application of muscles in the animal body having been discussed by our author in three former t lectures, he now proceeds to treat of the action of muscles on the ;: blood-vessels, an inquiry which, however essentially it may contri- 4 bute to our better acquaintance with the animal ceconomy,'has yet, fe it seems, till now been but little attended to, the existence of mus- i,„ cular fibres in the system of blood-vessels being by no means R obvious. " Mr. H. finds it necessary previously to lay down some general ^ principles concerning muscles, which he derives from their opera- «,; lions" in those parts of the animal where their uses are well un- % derstood. / CROONIAN LECTURES ON MUSCULAR MOTION. 2G3

" A muscle he defines such an arrangement of animal matter as, whilst it is endowed with life, is fitted for self-motion. This motion, he says, consists in the contraction ofthe muscular fibres, in which light "he considers it as totally distinct from elasticity. And he ventures to assert that no part of an animal except the muscles is endowed with this power of self-motion. He acknowledges soon after that this power cannot be the sole effect of contraction, but that there must also be a power of relaxation, acting alternately, without which no effect could be produced. But even this relaxation, he says, is not sufficient to produce any effect without a prei vious elongation ; and as no muscle is, as such, possessed of this ' power of elongation, he considers it as the effect of antagonists of some kind or other, or of what may be called the elongators ofthe msscles, and says, that it is not in all cases muscular, but sometimes the effect of elasticity, and sometimes even of matter foreign to the body. This leads him to distinguish it into three kinds; the first, where it is immediately muscular, or when antagonist muscles act immediately upon each other; the second, when a muscle acts upon some other matter, and gives it the power of an antagonist, as is the case in all those muscles that enter into the formation of canals or cavities, whose elongation is produced by other muscles, which have no immediate connexion with them, but which force them to an extension by propelling the contents of the canal, instances of which we find in the oesophagus, the intestines, and the bladder; and thirdly, when the elongation is owing to elastic substances, which sometimes cooperate with, and sometimes resist the action of muscles; and of other powers, such as gravitation, velocity, &c. "The second section treats of the application of the muscular and elastic powers, where both indisputably act. The joint application of these two powers we are told is very common, though hitherto it has been but little noticed. Elasticity operates where constant or stationary action is wanted. Muscles are applied where occasional action is required; and where both effects are wanted both powers cooperate. This is illustrated by various examples, among the rest that of a bivalve, which has a muscle between the two shells, for the purpose of closing them, and an elastic ligament in the joint, which constantly tends to diverge them. ''Another instance, much more to the present purpose, is that of the elastic cartilages and membranes of the trachea, and its branches,. which maintain an equilibrium by counteracting the tendency the muscles of respiration have to contract that channel. " In most parts of the body the muscles are so well defined that their existence is evinced by merely viewing their structure and colour But this is not always the case, and we especially find that in the blood-vessels no traces of muscles are distinguishable by mere inspection. „ . „ , " Here then other modes of information are requisite, and our author proposes two. The one is their effect when we see actions 264 HUNTER ON THE ANIMAL CECONOMY.

that are. in every respect muscular, although no muscle be distinguishable by the eye ; and the other the change that takes place after death, when, as Mr. H. has observed, in many cases the power of contraction preponderates so as to stiffen all the muscular parts; and when, if the muscles thus contracted be afterwards stretched or put into what in the living body may be called its relaxed state, they remain thus relaxed without showing the least tendency to any further contraction. These circumstances mark the difference between muscular and elastic parts, since this latter power continues to act after death much in the same manner as it did during the life of an animal. " These two modes of information are next applied in the examination of blood-vessels, which, our author previously observes, seldom bear any visible marks of muscular construction, and scarce ever admit of examining from their effects in the living body, on which account the second mode of information must be adopted as the likeliest to furnish some lights in this inquiry. He made a set of experiments on the blood-vessels of a dead horse, which were taken out so carefully as not to affect in the least either their texture or degree of contraction. They were examined both in their natural state and after they had been opened, and stretched different ways, by which means the diflerent actions of the muscular and of the elastic powers become easily discernible. The following are the principal facts that resulted from this examination: "Every part of the vascular system is not equally endowed with muscles; the larger vessels, especially the arteries, being chiefly composed of elastic substances, whilst many parts of the smaller, or what are called the capillary vessels, appear to be almost entirely muscular. " In the middle-sized arteries two substances are visible to the eye, that towards the inner coat being evidently darker in colour, and of a structure somewhat different from the outward. The relative thickness of these coats differs as we recede from the heart, the interior becoming considerably thicker in proportion to the exterior ; whence it evidently follows that the external diameter of the duct is not to be inferred from its external thickness, this being always proportionably greater as the vessel diminishes in size. Both these coats are in some measure elastic, but the external is more so than the internal; whence it may be judged that it is the internal that is endowed with muscular properties. This indeed is confirmed by a variety of experiments, in which it was found that the inner surface after death was considerably more contracted than the outward, the latter being thrown into longitudinal corrugations, which could only be the effect of the greater transverse or circular contraction of the latter. •' It has further been observed that this muscular contraction is chiefly in the transverse direction, and seldom if ever longitudinal. " The physiological application of these facts, especially to arteries, is briefly this. The muscular contraction being chiefly circu- CROONIAN LECTURES ON MUSCULAR MOTION. 265

lar, and tending to lessen the diameter of the vessel, tbe animal ceconomy would suffer greatly if in the larger arteries, where this contraction is greater in proportion as its diameter increases, some power did not counteract this tendency so as to maintain a middle state or equilibrium. Thus also when muscular parts are too much distended, which in large arteries will often happen on account of their vicinity to the heart, a similar power is requisite to contract it to its natural size or tone. In both cases the elastic power produces the necessary effect, and it seems to follow hence that this power must always be proportionally greater in the larger vessels than in the smaller ones. "A Table, exhibiting at one view the results of the above-mentioned experiments concludes this lecture."* 24. CROONIAN LECTURE ON MUSCULAR MOTION, No. V.

[Read before the Royal Society, June 14, by Mr. John Hunter, F.R.S.]

Of the Contraction and Relaxation of Muscular Fibres.

Muscular motion differs from every other motion in matter; it is a motion taking place in the component parts of a muscle, and not a change of their relative situation. It is an uniform approximation, and receding in all the parts; the size, construction, and connexion of these are as yet not known : it is similar, as far as we can discover by our senses, to elasticity; in both cases the motion is produced in the component parts, which we are as yet unacquainted with, and only see the ultimate effect. For the better investigating this motion in muscles, we may divide the general motions in matter into four kinds.

* [The irritability, or muscularity, of part of the coats of the artery contended for in the preceding lecture by Hunter, has since been demonstrated experimentally, first, by Dr. John Thompson of Edinburgh, and subsequently by many other physiologists; in whose experiments distinctcontraction ofthe small arteries was produced,not only by mechanical (Wilson Philip, Hastings, Kaltenbrunner) but by galvanical irritation. (See Wiedcmeyer, Experimenla circa Stalum Sanguinis et Vasorum in Infiammatione, Monachii, 4to., 1826, and the Bibliography of the Vascular System, vol. iii., p. 226.) The muscular action is easily seen by dropping water colder than the atmosphere upon the capillaries in [the mesentery of a frog, which thereupon contract both longitudinally and transversely, and after a little while resume their ordinary dimensions. Nevertheless ihe best chemists agree in classing the fibrous coat of arteries with the nonalbuminous textures, as cellular tissue, cartilage, &c. The ultimate fibres of he middle coat, viewed microscopically, are smooth, branched, and anastomose reticular'y, like the fibres of involuntary muscles : they present a remarkably clear dark outline.] 24 206 HUNTER ON THE ANIMAL CECONOMY. The first is the motion of whole bodies by means of an external impulse, the vis inertia of the body being overcome. The second is the motion from attraction of one species of matter to itself or to another species, as wholes. Of this kind is gravitation, perhaps magnetism and electricity, probably also cohesion. The third kind of motion is from chemical attraction, where, besides the attraction of whole parts, there is an elective attraction between the particles of one kind of matter and those of another, as it were drawing them out from the general mass. This can only happen when suspended in a fluid or in the form of vapour, no other form admitting ofthe motion of particles among themselves. Repulsion produces a similar motion among the parts. The fourth kind of motion is muscular, arising most probably from construction, and a principle in action very different from the attractions in common matter. This action and the others are equally unintelligible, the general effect alone being evident to our senses. From the effect in muscular motion, we should be inclined to suppose that there is an approximation ofthe parts in one direction, which in the whole produces a visible contraction. It is natural to suppose that all muscular fibres act alike; that every fibre in every muscle when in action is under exactly the same circumstances: therefore whatever variety may appear in muscular action, or difference between the action of different muscles, must depend upon the various causes and intentions of these actions. A muscle in action as it contracts becomes more dense or hard, and therefore <i priori we should suppose it becomes less, as we can form no adequate idea of the same substance becoming firmer or harder without either an approximation of its parts, or an addition of new matter introduced into all its parts, or a particular position ofthe constituent parts of a muscular fibre, so as to become immoveable while in that position. One circumstance, however, which makes muscular fibres firmer when contracted in the living body is, their always overcoming some resistance in such contraction, which puts them more or less in the situation of a stretched cord. Take the unattached hairs which compose the strings of the bow of a fiddle, and they will feel pliant or soft; but when put upon the stretch they will feel much firmer. An elastic body also, as India rubber, feels much firmer while stretched than when contracted and at ease, by its natural elasticity. A muscular fibre, however, in the state of tension between the two points is little indebted to this cause for its firmness, although it will increase the effect produced by the position of its component parts; for a muscular fibre unattached is very much increased in hardness while contracted, as in crimped fish,* and in the flesh of all animals * [Sir Anthony Carlisle found that the contracted muscles in crimped fish had not only acquired a sensible rigidity, but also an increase of specific gravity. See his ' Croonian Lecture for the year 1804,' Philos. Trans., 1805, p. 1.] CROONIAN LECTURES ON MUSCULAR MOTION. 267

allowed to die so gradually that the muscles, from the stimulus of death taking place, contract: but a muscle is as firm and as strong in all its degrees of contraction as it is in its full contraction, if not firmer and stronger than in its ultimate; therefore cannot be called contraction. It is its proximity of its parts arising from that attraction, not from the proximity of such parts mechanically, but attractively. Many authors of authority, as well physiologists as others, have attempted to explain the contraction of a muscular fibre; but, however ingenious their opinions may be, none of them completely account for any one particular, relative to muscular contraction: I shall, however, mention them, with the objections to which they are liable. In the investigation of this subject the following apparent alteration in the figure of a muscular fibre has been principally attended to: When a muscle acts, it increases in thickness, and becomes visibly firmer in texture, therefore each component fibre of the muscle must be supposed to undergo the same change ; and many experiments have been made to ascertain whether this increase of thickness in a muscular fibre is in proportion to its decrease in length, but hitherto without effect: probably the only method of ascertaining this fact is, to determine whether a muscle in the state of contraction is really increased or diminished in its bulk. Haller, in his Elements of Physiology, asks the following questions: "Does a muscle really increase in bulk in its action? As a muscle, when it acts, becomes shorter, and swells, we may next ask, Do these two changes, contraction and dilatation, compensate each other? that is, Is there the same quantity of matter in it at both these periods ? Or does a muscle in action really lose in its size?or does it gain in bulk what it loses in length? Both sides ofthe question have had their advocates." Borelli, to find out whether a muscle really had an addition of new matter in its contracted state, and thereby became heavier, made the following experiment: He placed a naked man upon a table suspended upon a point, which supported it directly under his buttocks, in which situation he was perfectly balanced. He was then desired to act with the muscles of the lower extremities, but he still kept his balance, no change taking place in the equilibrium. (Borelli, vol. ii., p. 39.) This experiment was made most probably upon the supposition that some additional matter was to flow from the brain along the nerves, or from the heart along the vessels to the muscles of the extremities, so as to render the upper part lighter, and the lower part heavier. If it was to come from the brain, it was conceiving the supposed animal spirits to be heavier than air, of all of which we are wholly ignorant. The celebrated experiments of Goddard, Glisson, and Swammerdam are quoted, to prove that muscles lose in their bulk while in action. They put a muscle or a whole limb into a glass vessel, 268 HUNTER ON THE ANIMAL CECONOMY. and filled it up with water; they then made all the muscles act at once ; or if a single muscle, they irritated the nerve, and made it contract, during which time they attended to the motion in the water, and its rising or falling was to determine whether the size of the muscle was increased or diminished. Swammerdam, in trying this experiment with a single muscle (the heart of a frog), saw the water sink in the contraction of that muscle, and rise in its relaxation. The result of this experiment has been very differently explained. Swammerdam himself doubted its being conclusive, believing the air might be compressed during the heart's action ; but we have no proof of the presence of air in a muscle in the simple state of air. Boerhaave and Sauvages accounted for the water descending by the blood being pressed out by the contraction of the muscle, which blood was returned into it by the relaxation, and raised the water. This certainly would be the case in the experiment made upon a whole limb: for we know, from every day's experience, that in bleedings from the arm the blood is thrown out more forcibly while the muscles are in action : therefore there is less blood in the vessels of the limb when the muscles are contracted than in a state of relaxation, and of course the limb is less in bulk at that time than in the other : but when a single muscle or a whole animal is immersed in water, whatever loss the muscle has in its substance must be gained by the water, so that the whole can neither be diminished nor increased. Hambergerus tied a string round a man's arm, and found that during the action of the muscles it cut him ; he therefore thought that muscles in action were increased ; but the experiment only proved that it became thicker, which is generally allowed. It has been objected to such experiments, that if a person acts only with one set of muscles, their opponents become stretched or relaxed in proportion, keeping up an equilibrium in the part: as antagonizing muscles, however, never bear a just proportion to one another in strength, it follows, that if we act with the strongest set of muscles the limb will of course become thicker in the proportion that the strength of the acting muscles bears to the strength ofthe relaxing ones, and vice versa. To ascertain with as much precision as possible whether a muscle really alters in size or not when contracted, I repeated the experiments of Goddard, Glisson, and Swammerdam, but in such away as to have little or no doubt what was the effect. I got a glass blown which contained almost a gallon; its mouth was about three inches over, to admit its receiving a pretty large muscle, and was fitted with a ground-glass stopper, which was water-tight, and a glass tube was fitted into this stopper, so as to communicate with the cavity of the glass, being at the same time water-tight. This apparatus could be filled with water, and have the water stand at any height in the tube which might "be required, so as to give with CROONIAN LECTURES ON MUSCULAR MOTION. 269

great nicety the comparative size (should there be any difference), of a muscle when contracted and when relaxed, while immersed in it. The muscles best adapted for experiments of this kind are those which have no antagonists, for in that case the contraction of one muscle produces the elongation ofthe other. The muscle should be wholly detached, having neither origin nor insertion, as a muscle cut out of the body, or cut from its attachment, as in crimped fish : those muscles however are best which have no natural attachment, as the heart. In repeating such experiments it will be hardly possible to have the result of two exactly the same, for no two muscles will be equally relaxed at the beginning of the experiment, nor will any two muscles contract equally; but if there is one universal general effect taking place in all of them, that general effect becomes the result of the experiment, and is what is to be attended to. Experiment 1. I killed a dog instantaneously, and took out the heart as expeditiously as possible, and put it into the glass filled with water, and immediately after putting in the stopper with the glass tube fixed in it. I now observed the height at which the water stood in the tube. The heart had so far lost its action as not to contract and relax alternately, having only the power of contraction from the stimulus of death, and when put into the water was perfectly relaxed. It was allowed to remain in the water some hours; and it was observed, that by its apparent loss of bulk it had contracted considerably; and we also found that the water in the tube had fallen.* The next thing to be done was to ascertain how much the heart had lost in size, which was known by the quantity necessary to fill up the glass to the first height, which was sixteen grains. The size of the heart was equal to two ounces six drachms, and thirty-eight grains of water, that is, 1328 grains, so that the contracted state was to the relaxed as 82 to 83, or *3d part of the whole. Experiment 2. I took the heart of a sheep, whose size was equal to 13 ounces or 104 drachms of water; it lost in contraction 1 drachm; so that the contracted state was to the relaxed as T^*th part ofthe whole. Experiment 3. I took a live eel, which was gutted, to remove as much as possible everything not muscular, and then crimped, to destroy the attachment of most of the muscles. The eel was equal to 14 ounces and 133 grains, or 6853 grains of water, and it lost in contraction 39 grains, or TV th part of the whole.f

* It is to be observed that the water was kept in the same degree of heat through the whole ofthe experiment. t [In the experiments above detailed Hunter drew his conclusions, a3 to the change of bulk in a muscle during contraction, from the effects observed in the level 24* 270 HUNTER ON THE ANIMAL CECONOMY. As this animal was composed of muscles, bones, &c, some allowance is to be made for these parts, which will account in some measure for the difference in the result between this and the hearts, although in the experiments on the hearts there is a considerable difference between the two, arising from the reasons above mentioned. It appears, however, upon the whole, that a muscle loses more of its length than it gains in thickness, unless the apparent difference arises from an universal approximation of all its parts. As a muscle loses in its general size by the contraction of the length of its fibres, we cannot suppose that contraction to arise from the introduction of additional matter into those fibres; therefore the opinions that a muscular fibre is a hollow tube from end to end, or a chain of cells of various shapes, either rhomboidal or circular, according to the ideas of the authors of such opinions, and these cells being filled with foreign matter, must fall to the ground ;* inof the surrounding fluid, after the last contraction ofthe parlor ' rigor mortis.' In Mr. Mayo's well-known experiment, which is similar to the first of Hunter's, the ordinary contractions of the ventricles of a dog's heart, alternating with relaxations of the same parts, produced no perceptible change in the level of the water in the tube.a In comparing the above experiments, one cannot fail to be struck with the period during which the muscular contractions of the dog's heart continued. But as Hunter killed his dog instantaneously, it was probably by some sudden concussion or injury to the brain, when the action of the heart would be arrested, and the last contraction only would be witnessed, notwithstanding the expedition with which it was taken out. In Mr. Mayo's experiment the dog was killed by hanging, and the ventricles of the heart continued alternately to contract and dilate for a considerable time. Barzolotti, Prevost and Dumas, who performed similar experiments on smaller portions of flesh, also found no change of level to take place in the surrounding fluid during the contraction of the muscle. Gruithuisen and Ermann,b on the contrary, observed, like Hunter, a slight change in the bulk of the muscle during contraction. Ermann introduced into a glass vessel the posterior half of an eel, the intestines being removed. A metal wire was inserted into ihe spinal marrow, and a second into the flesh, and these were directed so as to be brought into communication with the pole of a galvanic battery. The vessel was then filled with water, so that a narrow tube, in which the apparatus ended above, was filled. In completing the chain, and during the contraction of the muscles, the water fell in the tube four or five lines, and again rose to the opening, when the muscle relaxed. If, however, the muscular fibre, which is generally admitted to have increased in density, and, according to the experiments of Sir Anthony Carlisle, in specific gravity, during contraction, has really diminished in bulk, the difference is so trifling that we can hardly avail ourselves of it in elucidating the nature of muscular contraction.] * [It is now generally admitted by microscopical observers that the ultimate muscular fibre is solid. The voluntary muscular fibres (' secondary fibres' of Prevost and Durnas, 'ultimate fasciculi' of Muller,) in the vertebrate classes, and those of insects, arachnidans, crustaceans, and cirripeds, present a microscopical character which distinguishes them from every other animal tissue: it consists of close-set, parallel, transverse, or slightly oblique and sometimes slightly curved striae. The fibres which present these stria? are divisible into component fibrillae, which have a knotted or beaded structure; this I have myself observed a Anatomical and Physiological Commentaries, vol. i., p. 12. b [Gilbert's Annalen, 40.] CROONIAN LECTURES ON MUSCULAR MOTION. 271

deed, this idea of a muscular fibre being a chain of cells does not account for any one phenomenon attending muscular motion, and is directly contradicted by two circumstances attending muscular contraction: the first of these is the muscle becoming rather less than larger in its contraction, which is just contrary to what must have happened if the contraction had been owing to that cause; the second is, that a muscle is capable of contracting much more than one-third of its length, and indeed, as far as we yet know, having no limitation, which could not possibly happen if they were tubes capable of receiving foreign matter into their cavities; for according to that idea, a muscular fibre should become thicker in its contraction in proportion as the diameter of a sphere is greater than that of a cylinder of the same area, which would be an immense increase. Although a muscle becomes on the whole somewhat less in its contraction, and has its ends brought considerably nearer together, yet it cannot be called attraction, for there is nearly the same reason for supposing a lateral repulsion, as the muscle swells out laterally almost as much as it contracts in the other direction. I do suppose that a muscular fibre is not one uniform body from end to end, but is made up of parts, which may be called the component parts of a muscular fibre; and I am apt to suppose that a change takes place in the position of those parts, during contraction, and this alteration diminishes the extent of those parts in one direction while it is increasing them in the other, although from the experiments it appears not to be in the same proportion; but what that alteration is I shall not pretend to determine.*

in the human voluntary fibre, and in that of the mole-cricket. Some physiologists suppose that the transverse striae result from the lateral apposition of the knots on the parallel fibrillar The muscular fibres of the mollusca and radiata, and the involuntary muscular fibres of the vertebrata, with the exception of those developed in the vascular layer of the germ disc, as the fibres ofthe heart, do not present the striated character.] * [According to the observations of Hales (Haemostatics, p. 59), and of Prevost and Dumas (Magendie, Journal de Physiologie, iii., p. 301), the change in the muscular fibre, at the moment of contraction, is from a straight to a zigzag line : the observation has been generally made on the rectilinear parallel fibres of one of the thin abdominal muscles (the rectus) of a young frog, stimulated to contract while under the microscope; and the conclusion is admitted as an established fact in the most recent works on physiology. I have been led to doubt this fact, from observing the contraction of the muscular fibres in small Filarias (such as commonly infest the abdominal cavity of the cod), and more especially from observing the contraction ofthe retractor muscles of the tentacles of a species of Vesiculuria of Vaughan Thompson, a compound polype-like animal, which, under the guise of a Sertularia manifests a much higher type of organization. Here each separate fibre of the retractor muscles is seen with great distinctness, and is characterized by a single knot or swelling in the middle. In the act of retracting the tentacles the fibres become shorter and thicker, especially at the central knot, but do not fall out of the straight line. After the retraction has been effected, the fibres fall into a wavy or zigzag position: but this is characteristic of their state of relaxation under the circumstances which bring their two attached extremities nearer each other. In like manner, in the parallel longitftJinal fibres ofthe Filaria, it is most evident that, at the moment of contraction, they become 272 HUNTER ON THE ANIMAL CECONOMY. Muscles have a disposition to throw themselves into wrinkles or corrugations when not in action, and when the position of the part moved by these muscles is such as allows the muscle to be in its shortest state, as in the biceps-flexor-eubiti after having bent the arm. If it is kept in that position by any other power, the biceps will leave acting and fall into wrinkles, adapting itself to the short distance between its origin and insertion; so that these wrinkles are a kind of substitute for the contraction that was in the muscle. The greatest strength in a muscle while in action is probably when it is half contracted, as we find that in all great exertions of muscular strength, where ultimate actions are to take place, the muscles employed are never allowed to relax their full relaxation, or contract to their full contraction. When a man walks with a heavy load his knees are a little bent, even ofthe leg he stands upon, which supports the whole while he is moving the other. The same thing takes places if he is weary; but if strong and full of activity his perpendicular joints may be kept pretty straight. The same thing also takes place in old people from the same cause; for as they become naturally weak, they become, like the strong, loaded with a heavy burden, therefore take on the same modes of action : the knees are never straightened, the back bent forwards, and all the parts that are constantly in the action of support are all getting out of the perpendicular, in which perpendicular state, although they might be mechanically stronger, yet they are muscularly weaker, therefore get into that position in which the muscles can act with the greatest advantage. The relaxers, which become the sustainers of the muscles in action, never allow themselves to relax to their full extent while the contractors are carrying on the motion of a part, as it would produce weakness. The relaxation of muscles when contracted involuntarily, but from obnoxious stimuli, will not relax by the will; nothing but a counter-stimulus of necessity can, and even that with difficulty. For instance, if we attempt to breathe obnoxious air, or if anything touches the glottis, it immediately shuts, and it is out ofthe power of the will to relax it; but the stimlus of the necessity of breathing brings it to again. A muscle that has but one determined use, or rather a muscle that has but one point of orgin and one point of insertion, always acts wholly when put into action, so as to bring

shorter and thicker, but do not alter their rectilinear position until the action has ceased when they fall like the parallel nervous chord, into zigzag folds, which continue until effaced by the restoration of the part to its usual length through the action of the exterior transverse fibres On relating these observations to my friend Dr. Allen Thompson, he informed lit™ A ■ TTTS the ?xP?»ment of HaI*s and Prevost on the frog, he had not SSlnlZgGl contmu.ng m contraction, and being simply shortened, and TJ^nll V^S™S Phcffi ; and he was led t0 SU8Pect' &** this and other ^tSnad^dT2^arrangement was not produced tm after the act of CROONIAN LECTURES ON MUSCULAR MOTION. 273

about its effect on the part of insertion ; I believe never one part of the muscle only, or only a few of its fibres, but the whole. This is not the case with muscles whose origin is broad and its insertion narrow, whose insertion is broad and its origin broad, or whose origin is narrow and insertion broad. But in spasm in a muscle a very few fibres may be seen to act; in short, any number may act, as it is not motion of the part that is the intent of the action. Relaxation.

Muscular fibres have a greater power of contraction than what is barely sufficient for the extent of the motion of the parts upon which they are designed to act. This is illustrated in the shell-fish called bivalve, for the muscle in that fish brings the two shells together; but if one of the shells be broken, so as to allow of a nearer approximation of the two insertions ofthe muscle, we find that they are brought nearer. It is also evident where the tendo- Achillis or patella is broken, for when that happens the fibres are allowed to contract to the full extent of their original contraction, and the parts heal in that position; in such cases the muscle is become shorter the whole length of its natural contraction, and the tendon is become so much longer; and in this case, if the muscle was not possessed of a greater power of contraction than was before made use of, or did not acquire a greater power, no motion could now take place, whereas we find the ultimate quantity of motion produced. If the power of contraction was limited to the quantity produced in a straight muscle, the same kind of fibres, when forming sphincter muscles, could not answer the intended purposes, as a greater power of contraction is required. That the same length of fibre is not absolutely necessary to produce in all cases the same effect, is strongly evinced, by the fibres of the gastrocnemius muscle in the African negro, being shorter than in the European, yet producing exactly the same quantity of motion in the joints which they move. This takes place universally in the Africans, and now and then is met with in men of other nations. This difference in the length of muscular fibres is a principal reason of the difference in the outline of most men from one another; it is at least a secondary cause, and should be particularly attended to by painters and sculptors, as it is a distinguishing mark between original nations. The contraction of a muscular fibre is produced by the following causes: simple mechanical pressure, as touch, the pricking of a pin, &c.; simple impression on another part which acts upon this by sympathy. 274 HUNTER ON THE ANIMAL CECONOMY. It is also produced by properties of matter which are not mechanical, as the essential oils, salts, acids, &c.; by affections of the mind and intentions of the will by means of the nerves; by the circumstances of the body itself at the time, as want, repletion, &c; and even by death itself. An animal that dies so slowly as to allow the stimulus of death to be felt by its muscles, has those muscles so contracted as to become stiff; whether this contraction is equal to the greatest power of contraction of the same muscle, in such a position ofthe parts in the living body, I do not know. In order, however, to ascertain how much a common muscle contracts from the stimulus of death, I cut out a muscle from a horse just after it was killed, and found that in the action of death it had contracted one-third, and that the muscle so contracted had become one-fourth thicker in its diameter, a proportion I believe it would have kept in the living body; also the same muscle, when stretched, or when put into what in the living body may be called the relaxed state, did not again contract. The contraction of muscles from the stimulus of death is a stronger contraction than the attraction of cohesion ofthe muscles themselves; therefore when a muscle so contracted is attempted to be elongated it generally tears asunder: but this is not always the case, it only takes place under certain circumstances; it is with respect to the muscle itself in proportion to the power of contraction of the muscle, for we find it takes place much oftener in those that die of violent deaths, especially when they die of strong convulsions; it seldom or ever takes place in those which die of a disease of some standing, for in them the muscles have lost in some degree their absolute power of contraction; as also the disease may be such as has in some degree destroyed the stimulus of death upon the muscles, so that their contraction will be less, although their power may be pretty strong. It would appear from the above that muscular contraction is not simply an approximation of the parts of which a muscular fibre is composed. What the difference is in a muscular fibre between its relaxed state and the contracted, perhaps may never be known. Relaxation would appear to be a natural consequence of the contraction having answered its end or fulfilled its purpose; or it may be supposed to have got rid of its stimulus by this action, the stimulus ceasing to have power when the action has taken place; therefore relaxation naturally occurs till excited to action by another sitmulus, of which it is susceptible. Relaxation might be supposed to be a simple cessation of action, but I think it is not; it appears to me to be a power as much depending on life as contraction; for if it was simply a cessation of action, muscles would become relaxed that had contracted by the stimulus of death whenever absolute death took place, which is not the case; on the contrary, it takes probably as much force to CROONIAN LECTURES ON MUSCULAR MOTION. 2?f>

overcome this contraction as the same muscles would have done when acting with all the power of the will in the living body. From the violence necessary for the elongation of a muscular fibre after death, it would appear that the position of the component parts of a fibre in any degree of contraction is such as requires force to alter or remove it, and, whatever that position is, it can be in part drawn out as if only in part contracted, or wholly drawn out; and in this operation of drawing out or relaxing a muscular fibre after death, we may observe there is a recoil or reaction in a certain degree when the elongating force is removed, becoming in this respect similar to elasticity. This recoil, however, is not extensive, although it takes place in every degree of relaxation, from the most contracted state to the almost totally relaxed state. I first observed this recoil in a man who died in convulsions in St. George's Hospital, from a fever, attended with delirium, which was brought on by a hurt on his arm, which inflamed considerably. A kw hours after death his muscles were stiffer than usual, and extremely well marked through the skin, which induced me to make the following experiment on the relaxation of muscles. I laid bare the rectus muscle ofthe thigh, and separated it from the other muscles without stretching it; I then passed a thread behind it and inclosed the muscle, and cut the thread off where the ends met. Upon bending the knee the muscle was stretched, and I found that the ends of the thread were lapped over each other. Upon measuring the difference it was one-eighth of an inch diminished from what it was in the contracted state. I was much surprised by a considerable degree of contraction in , the muscles, similar to elasticity, for they evidently contracted a good deal after being stretched. I suspected that this had arisen from some remains of life, and therefore waited till the next day, when the same thing happened. If, in stretching a contracted muscle after death, the fibres are not drawn out beyond this power of recoil, the whole contraction of the muscle (whatever quantity it is) continues the same; but if the muscle is drawn out further than this power of recoil, then the muscle becomes so far relaxed, but no further; for instance, if the recoil is the one-twelfth of an inch, and the muscle is only stretched so far, then the muscle will contract again one-twelfth of an inch; but if it is stretched one-sixth of an inch, then it will still only recoil one-twelfth, the other one-twelfth being the absolute relaxation of the muscle. From all that is mentioned above, I think it will appear that relaxation of a muscular fibre depends upon life as much as the contraction, neither the one nor the other being produced after death by any property in the muscle. The causes of relaxation are few ; the will is perhaps the principal one, although not in all muscles. Emotion of the mind would appear to have a power of stopping the action of the heart, but is perhaps only hindering a new contraction. 276 HUNTER ON THE ANIMAL CECONOMY.

The contraction and relaxation of a muscle are always adapting themselves to the motions of the parts on which they are to act, so that if a joint continues bent for sometime the muscle will retain it in that situation, and any extension of that joint will put the muscular fibres on the stretch. This is not, as has been supposed, a contraction ofthe tendon, but a contraction in the muscle, to adapt it to the remaining motion in the joint, this half contracted state becoming now the state of relaxation from which the muscle is in future to produce its action. The point of relaxation of a muscle, therefore, is always the extent of motion in the joint, and the quantity of contraction of a muscle is always equal to the full motion ofthe joint on which it acts, and if the joint loses part of its motion the muscle also loses a proportionable degree of contraction, so as still to be adapted to it. Muscles, however, so contracted, may be gradually stretched to their original length, and recover their original action, as the bicepsflexor-cubiti after inflammations, and abscesses in the arm. Muscles may be also stretched beyond their original length, and still retain their use, as those of the belly in dropsies. These circumstances prove that accidents to the body are provided against in its construction; for if the muscles remained in the half-bent state in the cases above mentioned, the length of muscle would be too great for the quantity of motion, and the first part of its action would produce no effect upon the joint. CROONIAN LECTURE ON MUSCULAR MOTION, No. VI.

[Read before the Royal Society June 13th, by Mr. John Hunter, F.R.S.]

An inquiry how far, and in what instances, the density or firmness of a Muscle contributes to its strength.

In comparative experiments respecting animals, where the actions ot life are attempted to be imitated in the dead body, we should attend to every circumstance and see whether there is really any kind of similarity in the experiment. But, where life is absolutely necessary for the action, on one side, and the action is imitated only so lar as regards the mechanical mode of performing it, the resemblance between the vital action and the experiment is in reality very remote. r To suppose that the action of a muscle should be equal, more or less, with its mechanical strength when dead is absurd, because they bear no analogy. 1 he action of a muscle is as unlike its mechanical CROONIAN LECTURES ON MUSCULAR MOTION. 277

resistance as the effects of the irritability of a living body upon impression is like the mechanical effects of the same impression; the mechanical effects being the same in the living as the dead. The action of a muscle is stronger than its mechanical resistance in the dead body; that is, its power of contraction is greater than the attraction ofthe cohesion of its fibres. These facts can only be ascertained by experirnents on the power in the living body, opposing them with the resistance in the dead; but as a muscle is in very different states in contraction and relaxation, even in the living body, and as the experiment is opposing contraction to the state of relaxation, the experiment is not conclusive: it does not prove what it is meant to prove. The subject can and should be viewed in several lights. A muscle is first to be considered in two points of view; the relaxed state, wrhere it is only united by the common attraction of cohesion of that muscle, and is probably as mechanically strong in the dead as the living; but they may be considered in the contracted state both in the dead and the living, for although a muscle does not contract after death, yet it often contracts in the act of dying ; and death does not produce a relaxation, therefore it is to be presumed that the position of the parts of the muscle so contracted remains in the same state, and therefore such muscle affords an opportunity of making comparative experiments between it and one in the living body so contracted. How far the same muscles in the dead body, when fully contracted, could be relaxed by the same force as when in the living state, I do not know. It is certain that a muscle in health, and which feels the stimulus of death strongly, contracts with considerable force, and requires a considerable power to overcome it; therefore the relaxation of a muscle, voluntarily contracted, must always be an act ofthe mind, or a cessation of action of the mind upon that muscle. But when a muscle takes on an action without the mind, either in diseases, as the involuntary actions of voluntary muscles, or by the stimulus of death (the immediate cause of action being, I conceive, the same in both), then a relaxation^from the mind cannot take place in either, because the mind had nothing to do with the first, and it did not exist in the second. So that those involuntary actions of voluntary muscles arise from a stimulus independent of the will, and in those where it goes off it is because that stimulus can cease, and the part being alive a relaxation can ensue; whereas in death a relaxation cannot ensue, because a cessation ofthe stimulus cannot ensue, that cessation being an act of the living body. To oppose an experiment on muscles in the dead body with one in the living, the muscles should be always in similar states, for a muscle contracted is thicker than natural, and therefore stronger in its transverse direction; and if when in a contracted state the particles of which it is composed are really brought nearer to each other, then it should be doubly strong, viz., in proportion to its in- 278 HUNTER ON THE ANIMAL CECONOMY. creased size and closer approximation of its particles. But as the state of a muscle in contraction is totally different from its natural state, or that state which constitutes the natural structure of a muscle, no comparative experiments can be made which can explain anything. It is evident from observation, that in the construction of a muscular fibre it was not necessary that they should be all of equal density, for we find some fibres denser than others. We find this difference in the different tribes of animals; in some the fibres are extremely soft, while in others they are very firm. The firm fibre is found in the more perfect animals, called quadrupeds, especially when full-grown; and this difference of density of muscular fibres would appear to be in a pretty regular gradation from the most imperfect to the most perfect, from the muscles of the medusa to those of the full-grown quadruped. We may also observe that the first rudiments of every animal are extremely soft, and even the rudiments of the more perfect are similar to the full-grown imperfect, and as they advance in growth they become firmer and firmer in texture. It may likewise be observed that there is a very considerable difference in the densities of the muscles in some of those animals that are of distinct sexes, the male (probably in most) having by much the densest muscles: and the muscles of the same animal, whether perfect or imperfect, are not of equal densities, some being denser than others. This arises from two causes,—one natural, growing up with the animal, the other acquired by frequent action. This difference in density of the muscular fibres in different animals, and in the same animal at different ages, in different sexes of the same species, and even in the same sex, also the increased density arising from action, must answer some material purpose, and, from every observation, it would appear to produce strength or power in the contraction of the muscular fibre. From every circumstance attending muscular contraction, it is obvious that those muscles employed in, or intended for the strongest actions, are the firmest in texture of any animal body, at least from many circumstances it is natural to suppose so ; that they are the strongest would appear from the situation in which the firmest muscles are placed, for where the strongest actions are found in the living body, there we find the firmest muscles after death. There are two causes for this situation of the firm or strong muscles ; the first is an original or natural one, a principle in the animal ceconomy, depending upon the natural growth ofthe animal as much as the formation of a leg or any other part. The second is action. If we take a general view of the first or natural cause, we shall see from these general observations where we are to expect the strongest, and of course the hardest, muscles in any given animal whose mode of action'is known. CROONIAN LECTURES ON MUSCULAR MOTION. 27!)

In animals which have progressive motion it will generally, if not always, be found that this action will be one of their greatest, because the parts intended for progressive motion bear a small proportion to the whole animal, which they are obliged to move ; whereas, every other part has its peculiar muscle, and the muscle is only obliged to move that one part, which is small in proportion to the others. Another action which many animals are endowed with, and which requires very considerable strength, is fighting; this is an action which always requires great powers in the muscles, because it is an action in a part which is to overcome the whole strength and weight of its antagonist, which is more than the natural weight of the same muscle, or the resistance of the same muscle, or the resistance of any muscle in the same body. Another partial cause of strength in some animals is for catching their prey, which is to overcome a resistance considerably beyond the motion of the part itself which is to perform the action. If such parts of animals as are adapted for progressive motion, for fighting, or for catching prey, require the greatest strength in the muscle adapted for such purposes, and if we find that such parts as are endowed with the firmest muscles are strongest, where all those purposes are united in the same part in any one animal, we must find there the greatest strength, and of course the firmest of all the muscles in the body, especially if every one of these actions is considerable or violent. Thus, then, we find the muscles in the arm of a lion where all these three purposes are performed, are extremely firm in texture, and we must suppose are also exceedingly strong. The muscles of the thigh of a fighting-cock are employed in fighting and progressive motion, and are extremely firm. The muscle which has the greatest resistance in an animal body to overcome is the heart, especially in quadrupeds, and this is perhaps the firmest in the body, being even firmer than those which have the above-mentioned resistances to overcome; but the firmness of this muscle may in some measure arise from its action, which I called the second cause of firmness. Some muscles in the more perfect animals are much firmer than others in the same animal; such is the muscle which draws the snail into its shell, and retains it there against almost any power that can be applied; also the muscle which shuts the two shells of the bivalve is very firm in its texture, and we know that itis exceedingly strong. A difference is sometimes found in firmness between the muscles of the male and female; this, however, is not universal, not taking place in fish; but in all animals where the males have a disposition to fight and the females not, or at least in a less degree, I believe the muscles of the male are much firmer than those of the female, and this in proportion as their disposition for fighting is greater; 280 HUNTER ON THE ANIMAL GGCONOMY.

therefore in beasts of prey, where the disposition to fight is nearly equal in the male and female, the difference in strength is not so remarkable as in many other animals, there being very little difference between a male and female cat, a dog and bitch, a male and female hawk, &c.; but the muscles appropriated for catching prey, and also for fighting, are much firmer than the other muscles in the same body allotted for common purposes, and according to our reasoning they must be much stronger. We find, however, in animals which do not catch prey, and where the male has a strong tendency to fight with the males of its own species, while the female has this disposition very little, if at all, that there is a very considerable difference in the strength ofthe same parts in the male and female while alive, and a similar difference in the firmness of their muscles after death. There is a considerable difference between the muscles of a.bull and cow, and also between those of a cock and hen. Besides the general strength of the muscles of those males who fight, as they have parts which are intended for this purpose, we find that the muscles of those parts far exceed all their other muscles in firmness ; as the muscles in the neck of the bull, and the legs ofthe cock, far exceed in firmness all the other muscles in the body, and exceed, therefore, in a much greater degree the muscles of the female. We may also observe, that all those muscles in the male immediately employed in fighting, although not intended for this action alone, having other actions which are common to the female, besides being firmer than those of the female, are very considerably increased in size ; thus the muscles of the neck of the bull, and of the stone horse, those of the legs of the cock, &c, are much thicker and larger than in the female. The second cause of firmness in a muscle, and which contributes to its strength, is action, or what is commonly called exercise, and which has in general been considered as the principal cause of strength, size, and firmness. This may be called accidental, as it is not confined to any order of animals, or any one set of muscles ; it may, however, be observed, that the muscles employed in progressive motion and the purposes above-mentioned, are more subject to this accidental cause of firmness than any other in the body, both from the natural actions of the body, and also, being naturally firm and strong, from more readily being employed in violent actions. Thus we find the muscles employed in progressive motion are much firmer than any other muscles in the same animal, both from nature and action, except in those in the fighting males (who do not catch their food by violence), which are employed for that purpose, as in the neck of the bull. The heart of all animals partakes strongly of the two causes of firmness, and is perhaps the firmest muscle in the body. This firmness in the heart is very early in life, for in the small embryo the CROONIAN LECTURES ON MUSCULAR MOTION. 281 heart is a pretty firm manageable part, while every other muscular part of the animal is as tender as jelly. Constant action not only gives firmness to muscles, but increase of size. The epicure is no less sensible of the effects of these causes of firmness than the physiologist, and therefore prefers the inactive parts; and the leg of the woodcock, the breast of the partridge, pheasant, turkey, &c.,are held in high estimation. He even takes pains to diminish the effects which arise from exercise, &c, by feeding animals in such a way as to prevent them taking place.— Upon This principle house lamb, veal, &c, are made tender. How delicious to the sensualist must the flesh ofthe sloth be, if the account of its motion being far exceeded by a snail is true! From the above account it must appear that muscles, in proportion as they are firm in texture, will be strong in action; it is at least demonstrable in the muscles of the same animal whose texture is different, and in similar muscles in the male and female of the same species, and we may reasonably suppose that it will hold good in different species; and therefore, when we find the muscles very firm in any one species, we may conclude that this species is stronger than any other species in which the muscles are tender and soft. This firmness in a muscular fibre we may suppose to arise from the density of its component parts, or those parts being closer together, the uniting medium being less in quantity ; this, however, it is perhaps impossible to determine exactly. That this idea may be better understood, I shall suppose that a part composed of dense parts (aggregated) at a given distance, will be firmer than a part composed of less firm parts at the same distance; and it is plain that a part composed of any given substance will be dense in proportion as the parts of that substance are near to each other. It may probably be similar to iron and steel; in the iron the parts or"crystals which compose the mass are large, and perhaps not regular. In the steel they are small, and probably more regular in thefr figure, by which means they can adapt themselves better to each other, and still more so if tempered, according to the degree of temper, so that their crystals shall become still smaller, and of course the whole becomes harder. To ascertain whether the firm muscles really contained more matter, and were therefore specifically heavier than the soft, I made several experiments upon muscles of different densities. The experiments were made upon the same muscle of two animals of the same species whose muscles are of different densities, viz., the muscles of the neck of the ox and bull.* Nine ounces and a half of muscle from a bull's neck, and the

* My reason for choosing those muscles in preference to others was, that they admit a greater degree of difference in firmness, and that they have no tendons intermixed, so as to give density from that cause. 25* 282 HUNTER ON THE ANIMAL CECONOMY. same quantity from that of an ox, were weighed in water, when the bull's was thirty-one grains heavier, which is about Tj7th.* From this experiment it appears that there is some difference in weight between a firm muscle and one that is naturally soft or lax, although not great, not even so much as one might at first imagine, at least not so much as the apparent difference in density. As it appears, from the above observations, that with the same given size the firmer muscles are the strongest, it becomes a question why every muscle in the bodies ofthe more perfect animals, and in the young of such animals, as also the muscles ofthe more simple animals in general, should not all have been of this texture, which constitutes the greatest power of contraction ? This is perhaps not yet to be fully answered. It certainly would have rendered many parts ofthe more perfect animals much smaller than what they now are, and wrould have had the same effect upon the whole body of the young of the more perfect animals, as also of the more simple animals universally; we must, however, suppose that it would have been attended with some inconveniences, although at present what these inconveniences would have been may not be perfectly understood. 26. THE USE OF THE OBLIQUE MUSCLES.

Muscles are the active parts in an animal body, producing different effects, according to the circumstances in" which they are placed; and the greater number of parts requiring a variety of motions, it became necessary to have a variety of muscles suited to such motions. The function of a muscle depends on the contraction of its fibres; and the most general effect produced by this contraction is to move some one part of the body upon another. But we may observe, that when motion in a part is performed by one set of muscles, there are other muscles employed in regulating that motion, as in most joints; and in a whole part, destined to a variety of motions, and composed of smaller parts, intended likewise to have their distinct motions, we find muscles appropriated for the purpose of keeping some of those parts fixed in a particular position, while the whole part is to be moved by other muscles, according to the nature of the action to be performed. This will, perhaps, be best illustrated by attending to what takes place in the eye, considering it as part ofthe head. The eye being an organ of sense, which is to receive impressions from without, it was necessary it should be able to give its motions * [See note, p. 266.] THE USE OF THE OBLIQUE MUSCLES. 283 that kind of direction as would permit its being impressed by objects whether at rest or in motion, or moving from object to object; and it was also necessary that there should be a power capable of keeping the eye fixed upon an object when our body or head was in motion. For the better understanding this action of pointing the eye towards objects under the various circumstances of vision, it will be necessary to mention that the eye is furnished with muscles, some of which, in the quadruped, bird, amphibia, and fishes, are called straight, from their being placed in the direction of or parallel to the axis of the eye; and two, I believe, have always been named oblique. Of the straight, some animals have more than others. There are four straight muscles common to most animals; and those which have more have the additional muscles inserted immediately in the eyeball on its posterior surface, and surrounding the optic nerve. The four straight muscles, which are common to all quadrupeds pass further forwards, and are rather inserted towards the anterior surface of the eye. For vision at large it was not only necessary that the eye should be capable of moving from object to object, or of following any object in motion, but also necessary that there should be a power to keep it fixed on any one object to which the mind might be attentive; therefore the muscles are formed so as not only to be able to move the eye from object to object, but likewise to keep its point of vision fixed upon any particular one, while the eye is moving progressively with the head or body. This is the use of these muscles, when the parts from whence they arise are kept fixed respecting the objects the eye is pointed to ; but it is often necessary, while the eye is fixed upon a particular object, that the eyeball and the head in which it is fixed should shift their situation respecting that object; and this would alter the direction of the eye, if the muscles had not the power of taking up an action that produces a contrary effect, that is, keeping the point of insertion of the muscles as the fixed point, by causing their fibres to contract according as the origins of the muscles vary their position respecting the object. From this mechanism we find these three modes of action produced : first, the eye moving from one fixed object to another; then the eye moving along with an object in motion; and, last, the eye keeping its axis to an object, although the whole eye, and the head, of which it makes a part, are in motion. From either of these motions taking place singly, or being combined, the eye is always kept towards its object. In the two first modes of action the origins of the muscles are fixed points respecting the object; and, in the last, the object becomes as it were the centre of motion, or fixed point, commanding the direction ofthe actions ofthe eye, as the north commands the direction of the needle, let the box in which it is placed be moved in what direction it may. These two first modes of action are performed by the straight muscles ; for the head being a fixed point, they are capable of moving the eye 284 HUNTER ON THE ANIMAL CECONOMY. up and down, from right to left, with all the intermediate motions, which, taken together, constitute a circular movement; or, when the eye is to become the fixed point, then the head itself performs the circular movement. Thence appears the necessity why the object, the axis of the eye, and the point of sensation, should all three be in the same straight line. But this does not take place in all movements of that whole of which the eye makes a part; for besides those which we have already taken notice of, the head is capable of a motion from shoulder to shoulder, the axis of which is through the axis ofthe two eyes, from the fore to the back part. It should be here observed, that for distinct vision the object must be fixed as respecting the pupil of the eye, and not in the least allowed to move over its surface.* To prevent any progressive motion of the object over the retina of the eye, eitljer from the motion of the object itself, or of the head in some of the motions of that part, the straight muscles are provided as has been explained; but the effects which would arise from some other motion of the head, as from shoulder to shoulder, cannot be corrected by the action of the straight muscles, therefore the oblique muscles are provided. Thus when we look at an object, and at the same time move our head to either shoulder, it is moving in the arch of a circle whose centre is the neck ; and of course the eyes would have the same quantity of motion on this axis if the oblique muscles did not fix them upon the object. When the head is moved towards the right shoulder the superior oblique muscle ofthe right side acts and keeps the right eye fixed on the object; and a similar effect is produced upon the left eye by the action of its inferior oblique muscle: when the head moves in a contrary direction the other oblique muscles produce the same effect. This motion of the head may, however, be to a greater extent than can be counteracted by the action of the oblique muscles. Thus, for instance, while the head is on the left shoulder the eyes may be fixed upon an object, and continue looking at it while the head is moved to the right shoulder, which sweep ofthe head produces a greater effect upon the eyeballs than can be counteracted by the action of the oblique muscles; and in this case we find that the oblique muscles let go the eye, so that it immediately returns into its natural situation^ the orbit. Whether this is performed by the natural elasticity of the parts, or

* Optical writers seem to have been entirely ignorant of this ; for they not only suppose distinct vision compatible with the object having a motion over the different parts of the retina, but even explain the effects which would be produced by it on the mind of the observer. Keill mattes the following observation : " Since optics teach us that every body which is visible has by means of the rays which proceed from that object its image painted on the bottom of the eye or retina, it follows that those objects will seern to be moved whose images are moved on the retina, that is, which pass over successively the different pans of the retina whilst the eye is supposed to be at rest; but those objects will be looked upon as being at rest whose images always occupy the same part of the retina, that is, when the motion of those images are not perceived in the bottom ofthe eye."—Keill's Introduction to Natural Philosophy, p. 79. ON THE COLOUR OF THE PIGMENTUM OF THE EYE. 285

whether the antagonist oblique muscles take up the action and reinstate the eye, I do not know. If the head still continues its motion in the same direction, then the same oblique muscles begin to act anew, and go on acting, so as to keep the eyes fixed on the object. As this motion of the head seldom takes place uncombined with its other motions, some of the straight and oblique muscles will be employed at the same time, according as the motions are more or less compounded. 27. ON THE COLOUR OF THE PIGMENTUM OF THE EYE IN DIFFERENT ANIMALS.

In the eyes of all animals which I have examined there is a substance approaching to the nature and appearance of a membrane, called the pigmentum, which lines the choroid coat, and is somewhat similar to the rete mucosum which lies under the cuticle of the human body; and there is also some ofthe same kind of substance diffused through the cellular membrane which unites the choroid with the sclerotic coat. My intention at present is only to communicate the observations I have made on this subject and its use, confining myself to the consideration of that kind of it which lines the tunica choroides of the class Mammalia, and of birds; in doing which I shall also take occasion to speak ofthe difference of colour occurring in animals of the same species. Although an accurate examination ofthe appearances of a similar substance in the eyes of some fishes might illustrate the subject, we cannot avail ourselves of that, as from not being sufficiently acquainted with the effects of light upon the eyes of that class of animals. The propagation or continuance of animals in their distinct classes is an established law of Nature, and in a general way is preserved with a tolerable degree of uniformity ; but in the individuals of each species varieties are every day produced in colour, shape, size, and disposition. Some of these changes are permanent with respect to the propagation of the animal, becoming so far a part of its nature as to be continued in its offspring. Animals living in a free and natural state are subject to few deviations from their specific character; but nature is less uniform in its operations when influenced by culture.* Considerable varieties are produced under such circumstances, of which the most fre-

* From the variations produced by culture it would appear that the animal is so susceptible of impression as to vary Nature's actions ; and this is even carried into propagation. Whether this takes place at the very first union ofthe principles of the two parents, so as to derive its existence from both ; or whether it takes its formation from the mother, after the first formation of the embryo, are perhaps not easily determined. 286 HUNTER ON THE ANIMAL CECONOMY. quent are changes in the colour. These changes are always, I believe, from the dark to the lighter tints, and the alteration very gradual in certain species, requiring in the canary-bird several generations; while in the crow, mouse, &c, it is completed in one. But this change is not always to white, though still approaching nearer to it in the young than in the parent, being sometimes to dun, at others to spotted, of all the various shades between the two extremes. This alteration in colour being constantly from dark to lighter, may we not reasonably infer that in all animals subject to such variation the darkest of the species should be reckoned nearest to the original; and that where there are specimens of a particular kind, entirely black, the whole have been originally black? Without this supposition it will be impossible, on the principle I have stated, to account for individuals of any class being black. Every such variety may be considered as arising in the cultivated state of animals; but whether, if left to themselves, they would in time resume their original appearance, I do not know.* The colour of the pigmentum of the eye always corresponds, I believe, with that of the hair and skin, especially if the animal be only of one colour, but is principally determined by the hair; and the most general colour is a very dark brown, approaching to black, from whence it had the name, nigrum pigmentum.f The colour differs in different classes of animals, often in the same class, and even in the same species. In the human it is most commonly dark, in the ferret kind always light, and its difference of colour in the same species is evident from the variety observable in the eyes of different people. There is even a difference of colour in the same eye in many classes of animals, in all of the cat and dog kind, and perhaps in most part ofthe granivorous. In some it is partly black, and partly ofthe appearance of polished silver; and in many classes the variation from dark is of two colours: for in the cow, in sheep, deer, horses, and I believe in all animals feeding on grass, there are in the same eye certain portions of it white, and others of a fine green colour. The difference in colour of this pigmentum in the eyes of different animals ofthe same species is very remarkable : in the human species it is of all the different shades between black and almost white, and the same variety is seen in rabbits, mice, crows, blackbirds, &c, but in these it is of one colour only in the same eye. Every species is, perhaps, subject to such variations; and some of these are so extraordinary as with propriety to be denominated monstrous.J

* In vegetables, I believe, it invariably hotds good that, however improved by culture, if neglected, they soon degenerate into their first state. f As the colour of this membrane corresponds with the colour ofthe skin and hair of the person, it is probable that the people among whom it first got the name were dark. ° ° * ?er,h-?Vhe W°rd monstrous is too strong, or not exactly just. It certainly may be laid down as one of the principles or laws of Nature to deviate under ZTH f\\Cam^Tu-A h may a,lso be observed, that it is neither necessary, nor does it follow that all deviations from the original must be a falling off; it appears ON THE COLOUR OF THE PIGMENTUM OF THE EYE. 287

The variation in the colour of the pigmentum in different species of animals seems to depend on a fixed law of Nature; but the varieties which are met with in the same species are much less constant, being merely different shades approaching to black or white. But the extraordinary circumstance is its being sometimes unusually lighter or darker in individuals ofthe same species; and this difference not seldom starting up in the young without any hereditary principle to account for it. The human species is a striking example of the colour of the pigmentum corresponding with that of the skin and hair; and though the skin and hair of one person differs very considerably from the skin and hair of another, yet it is not in so great a degree as in many animals. There are cattle perfectly white, white sheep, white dogs, white cats and rabbits ; but there are few of the human species that we can say are perfectly white. They rather pass from the black into the brown, red, and even light yellow ; and we find this pigmentum, although only of one colour, varying through all the different corresponding shades. In the African negro, the blackness of whose hair and skin are great distinguishing characteristics, this pigmentum is also very black. In the mulatto, who has not the • skin so dark as the African, but the hair nearly as black, this pigmentum is of a shade not quite so deep ; yet still it does not approach so near to the middle tint as the skin, rather following the colour of the hair. In people of a swarthy complexion, as Indians, Turks, Tartars, Moors, &c, we find the hair always of a jet black, and this substance of a much darker brown than in those that are fair. In those of very dark complexions, and having very black hair, although descended from fair parents, the same thing holds good. There are few species of animals, or even individuals of a species, whose bodies are only of one colour. Crows and some others, are exceptions; but the greatest number are of two or more, being variously spotted or streaked either with different colours, or with shades of the same. Many species are constantly lighter in some parts of the body than in others; and, with a few exceptions, animals are generally lighter, as to colour, on the lower, or what may be called the foreparts, than on the upper or backparts. The fair man or woman may strictly be considered as a spotted or variegated animal. In many persons the hair of the head, eyebrows, eyelashes, beard, and hair on the pubes, all vary in colour. The hair of the three first may be called foetal, and are oftener all of the same than of a different colour; the two last are to be considered as adult hair, and are commonly alike in colour, which yet frequently varies from that of the fcetus, which last is more liable to change its colour than the other ; and the change is generally that of growing darker, especially on the head and the eyelashes.* This difference in the colour of just the contrary, therefore we may suppose that Nature is improving her works, or at least has established the principle of improvement in the body as well as in the mind. * The hair growing gray is not in the least to the present purpose. 283 HUNTER ON THE ANIMAL CECONOMY. the hair on different parts of the body is not so observable in those nations who are dark or swarthy, as in people inhabiting many of the northern climates. In animals which are variegated let us observe the colour of this pigmentum, and we shall find it regulated by some general principle, and corresponding with the colour of the eyelashes. The magpie, for instance, is nearly one-third, or fourth part white; and the two colours, if blended, would make the compound gray; but the eyelashes being black the pigmentum is black also. We sometimes meet with people whose skin and hair are very white and yet the iris is dark, which is a sign of a dark pigmentum ; but if we examine more carefully we shall also find that the eyelashes are dark, although the eyebrows may be the colour of the common hair. As the colour ofthe iris in the human species is probably a presumptive, though not a certain sign of the colour of this pigmentum, we may be led to suppose that in those who have the iris in one eye different from that of the other, this substance will likewise differ; but this I cannot determine, never having examined the eyes of any person with such a peculiarity. It is not an uncommon circumstance in some species of animals, the Angola cat seldom having the colour ofthe iris the same in both eyes. In people remarkably fair, whether they are of a race that is naturally so, or what may be called monstrous in respect to colour, as white ^Ethiopians, still we find this pigmentum following the colour ofthe skin and hair, being in some of a light brown, and in others almost white, according to the colour of the hair in such people. All foals are of the same colour, and whatever that may be, as they grow older it generally becomes lighter, therefore the pigmentum in them is almost always of the same colour, and does not seem to change with the hair. This change, however, is only in the hair, and not in the skin, the skin of a white or gray horse being as dark as the skin of a black one : yet there is a creamcoloured breed which has the skin of the same colour, whose foals are also of a cream-colour; and by inspecting the parts not covered with hair, such as the mouth, anus, sheath, &c, these, and the pigmentum of the eyes of such horses, are found of a cream-colour likewise. In the pigmentum of the rabbit kind there are all the degrees of dark and light, corresponding with the colour of the hair; yet there seem to be exceptions to this rule in some white rabbits with black eyes, and therefore with black pigmentum ; but in all such there is either a circle of black hair surrounding the eye or the eyelashes, and the skin forming the edge of the lid is also black. In many white cattle this is also observable ; and in that breed of dogs called Danes some have the hair surrounding one eye black, while the hair surrounding the other is white; and the iris ofthe one is often lighter than that of the other. This circumstance, of the iris of one eye being lighter in colour than that ofthe other, is a common thing ON THE COLOUR OF THE PIGMENTUM OF THE EYE. 289

in the human species; and sometimes only one half ofthe ins is light, without any difference in the colour of the eyelash or eyebrow. Whether this difference in the colour ofthe iris ofthe two eyes in the same animal is owing to the pigmentum being different in" colour, I do not know, although I rather suspect it is something similar to the white iris in horses, which makes them what is called wall-eyed. The variation of colour appears most remarkable when a white starts up, either where the whole species is black, as in the crow or blackbird, or where only a certain part of the species is black (but permanently so), as a white child borne of black parents ; and a perfectly white child, whose hair is white, and who has the pigmentum also white, though born of parents who are fair, should as much be considered as a play of Nature as the others. All these lusus naturae, such as the white negro, the pure white child of fair parents, the white crow, the white blackbird, white mice, &c, have likewise a white pigmentum corresponding with the colour of the hair, feathers, and skin. Besides the circumstance of animals ofthe same species differing from one another in colour, there are some distinct species which are, as far as we know, always of a light colour, and in them, too, this pigmentum is white : the animal I allude to is the ferret. When the pigmentum is of more than one colour in the same eye, the lighter portion is always placed at the bottom ofthe eye, in the shape of a half-moon, with the circular arch upward, the straight line or diameter passing almost horizontally across the lower edge ofthe optic nerve, so that the end ofthe nerve is within this lighter coloured part, which makes a kind of semicircular sweep above it. This shape is peculiar to the cat, lion, dog, and most ofthe carnivorous tribe; in the herbivorous the upper edge being irregular; in the seal, however, the light part of this pigmentum is equally disposed all round the optic nerve, and is, on the whole, broader than it is commonly found in quadrupeds. How far this increase of surface is an approach towards the fish kind, in which it is wholly of this metallic white, I will not pretend to say, but it is probable, as the animal is to see in the water as well as in the air, that it may be formed circular, the better to correspond with the form ofthe eyelids, which open equally all around, which seems to accord with what is observable in fishes, they being without eyelids. The colour of the pigmentum, whether white or green, or both, has always a bright surface, appearing like polished metal, which appearance animal substance is very capable of taking on, as we see in hair, feathers, silk, &c. After having taken notice ofthe various colours of this pigmentum in different animals, both where permanent and where it appears to be a play of Nature, let us next examine what effect it has upon vision in both cases, whether these effects are similar, or if one case illustrates the other. 26 290 HUNTER ON THE ANIMAL CECONOMY. It may be asserted as an undoubted fact, that the light which falls on the retina covering a white pigmentum has more effect than when it falls on the retina which covers a dark one; which is known by comparing the vision of those of the same species who have the pigmentum wholly dark with those who have it perfectly white; and something may be learned by a similar comparison of animals who have it only in different species, it being reasonable, from analogy, to suppose that some such effect is produced in the eye which is possessed of both. I shall first consider the effect produced when the white or light colour makes only part of the pigmentum. This will lead me to observe, that all animals having the pigmentum diversified, though they are capable of bearing as much light as others, and can see as perfectly when light is in an equal degree; can likewise see very distinctly when the light is much less than will serve the purposes of animals having it wholly dark. May we not, therefore, ascribe this advantage to the pigmentum being partly white 1 One might be almost tempted to suppose that such animals have a power of presenting the different parts of the eye to the light, according to the quantity of light required; or of moving the crystalline humour higher or lower : but we are at present unacquainted with any power in the eye by which these actions can be performed. We may observe, that when a cat or dog looks at us in the twilight the whole pupil is enlarged and illuminated, but in a full light there is no such appearance. It is plain there must be a reflexion of light from the bottom of the eye to produce the above effect, especially as the light reflected is always ofthe colour ofthe pigmentum in such animals, which in the cow is of a light green. I shall secondly consider those animals which have the whole pigmentum of a white colour, whether it is accidental or natural, and that see much better in the dark, or with less light than those in which it is of a dark colour; of the first of these I shall take my instance from the human species; of the second the ferret will serve as an example. Those ofthe human species who have the pigmentum of a light colour see much better with a less degree of light than those who have it dark ; and this in proportion to their fairness ; for when the hair is quite white they cannot see at all in open day without knitting their eyebrows and keeping the eyelids almost shut. In many of these instances there is an universal glare of light from the pupil, tinged with a shade of red, which colour, most probably, arises from the blood in the vessels ofthe choroid coat. I have likewise observed that the pigmentum is thinnest when it is light, so that some ofthe light which is reflected from the point of vtsion would seem to be thrown all over the inner surface of the eye, which being white, or rather a reddish-white, the light appears to be a^ain re^ fleeted from side to side.* This seemed to be the case in a boy at * How far this is really the case I do not absolutely say ; for whatever light comes through the pupil must be reflected from the point of vision ; but I imagined I saw the light passing through the substance of the iris. ON THE COLOUR OF THE PIGMENTUM OF THE EYE. 291 Shepperton, when about three years of age, of whom I have a portrait, to show that appearance. He is now about thirteen years of age:* the common light ofthe day is still too much for him; the twilight is less offensive. When in a room he turns his eyes from the window, and when made to expose his face to the light, or when out in the open air, he knits his eyebrows, half shuts his eyelids, and bends his head forward?, or a little down; yet the light appears to be less obnoxious to him now than formerly, probably from habit. Such persons appear to be nearer-sighted than people in common, but I apprehend that appearance to arise from the position into which they throw the eyelids and eyebrows, which not only in a great degree excludes the light, making the object faint in proportion to the contraction of the pupil and shade made by the eyelids and eyebrows, but at the same time fits the eye to see near objects; for if we nearly close our eyelids and knit our eyebrows we can see a small object much nearer than if we did not perform such actions, and it will make above a foot difference in the focal distance of the eye. In many rabbits who have white eyelashes, and in white mice, the pigmentum is entirely white, which is likewise observable in a certain distinct species of animals, the ferret, which we have adduced as an example ofthe pigmentum being naturally white; for these animals being intended to see in the dark, and their mode of life not exposing them to the light, they are liable to be affected by strong light to a greater degree than many others. If it is allowed as probable that in animals having the pigmentum diversified the object to be viewed is thrown upon the lighter coloured portion, how does it happen that such are able to bear the light better than those who have the pigmentum altogether of a light colour ? Perhaps it is not the illuminated object itself that is offensive to the retina, but that diffusion of light in the one kind of eye which does not happen in the other. Having stated the facts, and the general effect arising from the diversified pigmentum, let us consider the manner m which it is brought about, that such animals see belter with little light than those°which have the pigmentum wholly black. Let us then suppose the retina to be the organ of sight, and that by the rays which fall upon it being properly refracted it gives or conveys to the mind an idea of a distinct object, corresponding with the sensation of touch. This is the most common and simple manner in which vision is performed, and is that mode which takes place where the pigmentum is black, or nearly so, and where the greatest quantity of external light is required. The "retina, although somewhat opaque, is yet so transparent as to allow a considerable quantity of light to pass through it. For if this was not the case there could not be those differences in tne appearance of the eye which I have been describing. The rays which pass through, we may suppose, do or do not give sensation * The period here alluded to is 1786, when the first edition of this work was published. 292 HUNTER ON THE ANIMAL CECONOMY. in their passage ; and we may also suppose that only those which strike against the retina are the cause of sensation: but this is not the present inquiry; the rays which pass through the retina are what I am alone to consider, which falling upon the pigmentum are there disposed of according to the reflecting powers of that substance. If the pigmentum is black the rays will then be absorbed, and entirely lost, therefore in such eyes vision can receive no assistance from it, and consequently a considerable quantity of light is required to produce distinct vision ; but in those who have some part of this pigmentum white, we find that the rays of light which pass through the retina are reflected back again; and in this case it is not unnatural to suppose that the reflected rays, in their passage back, will strike against the retina, and increase the power of vision. It is evident that a considerable portion passes forwards through the retina, which, I suspect, is partly lost on the inner surface of the lateral and forepart of the eye, where the pigmentum is black, while the remainder passing through the pupil is again thrown on the object looked at. The next thing to be considered is, whether the shape of the eye is such as will throw the rays, which passed through the retina, back upon that membrane, in the same or nearly in the same place as that through which they originally came. The eye being a sphere, or approaching to that figure, makes it probable; but whether the curve is such as will reflect the rays exactly in the same direction is not so easily determined. If the curve be a true one, then the rays that are not obstructed in their return by the retina must pass forwards through the pupil, and, being refracted in their passage through the crystalline humour, will be sent out of the eye in the same lines in which they entered, and be thrown on the very object from whence they came; which seems to be in a great measure the case, if we may judge by the degree of illumination in the cat's eyes. If the rays reflected from the light part of the pigmentum should not, in their return, strike exactly on the same points in the retina, through which they first passed, yet if they are thrown nearly on the same place it will be sufficient, for we know that our sensations are not capable of conveying to the mind mathematical exactness. And the same circumstance will be a sufficient answer, should it be objected that the time lost in the passing and repassing of the rays may prevent distinct vision; for it is known that if an illumined body is made to move quicklv in a circle, it will appear to the eye a circle of fire. 28" S?t^t^1CT^RELATIVE T0 THE LATE MR. JOHN LECTURE PREpARATION FOR THE CROONIAN BY EVERARD HOME, ESQ., F.R.S. [Read November ]4,1793.] Mr. Hunter having announced to the Royal Society that he would make the structure of the crystalline humour of the eye the PREPARATION FOR THE CROONIAN LECTURE. 293

subject ofthe Croonian lecture for the present year, and having, unfortunately for science, died before his observations on that subject were rendered complete, I feel it a duty I owe to his memory as well as to the Society, to state the facts respecting this humour with which he had acquainted me; and shall subjoin an unfinished letter from Mr. Hunter to Sir Joseph Banks on the same subject. It is now many years that Mr. Hunter has had an idea that the crystalline humour was enabled by its own internal actions to adjust itself, so as to adapt the eye to different distances; and when the Tamia hydatigena* first came under his observation as a living animal, he was surprised to see the quantity of contraction that took place in a membrane devoid of muscular fibres, but made use of the facts in his investigation of the structure of the crystalline humour of the eye. Some time after this, having occasion to dissect the eye of the cuttle-fish, which he had frequently done before, but not with exactly the same view, he discovered in the crystalline humour a structure which corresponded with the idea he had formed of its actions in the human eye. He found it composed of laminae, whose appearance was evidently fibrous for some depth from the external surface; but becoming less and less distinct, till at last this fibrous appearance was entirely lost, and the middle, or central part of the humour, was compact and transparent, without any visible laminae. From this structure it would appear that in the eye of the cuttle-fish the exterior parts of the humour are fibrous, the interior parts not; so that the central parts is a nucleus round which the fibrous coverings are placed. The preparations which demonstrate these facts will be laid before the Society.f As the structure of the crystalline humour in the cuttle-fish differs in nothing from that ofthe same humour in other animals but in the distinctness of the fibrous appearance, Mr. Hunter was led to consider that the exterior part in all of them was similar, although no appearance of fibres could be demonstrated. • What I have here explained I was acquainted with at the time I had the honour of giving the Croonian lecture, in which I examined the different structures endowed with muscular action, and was desirous that Mr. Hunter would, either of himself or through me, communicate these observations to the Society; but this he declined doing till he had ascertained by experiment whether any muscular effect was really produced ; and the hope of being assisted by Mr. Ramsden made him, from time to time, put off making his experiments. In the course of this season he began his experiments, which were founded upon the analogy that ought to exist between this

* [The hydatid commonly found in the abdominal cavity of the sheep,—Cysticercus tenuicollis, Rudolphi.} . . t [The Hunterian preparations demonstrating the peculiarities of the eye of the cuttle-fish are not fewer than twenty. See Physiological Catalogue, 294 HUNTER ON THE ANIMAL CECONOMY. humour, if muscular, and others of a similar structure, which led him to expect that they would be acted upon by the same stimuli: and having found that a certain degree of heat, applied through the medium of water, will excite muscular action after almost every other stimulus had failed, it was proposed to apply this to the crystalline humour, and ascertain its effects. The crystalline humour taken from animals recently killed must be considered as being still alive. Such humours were to be immersed in water of different temperatures, and placed in such a manner as to form the image of a lucid, well-defined object, by a proper apparatus for that purpose, so that any change of the place of that image from the stimulating effects of the warm water upon the humour would be readily ascertained. These were the experiments which Mr. Hunter had instituted and begun ; but in which he had not made sufficient progress to enable him to draw any conclusions.

To Sir Joseph Banks, from Mr. Hunter.

" Sir, " When I did myself the honour of giving in my claim to the discovery of the crystalline humour being muscular, and proposed to make it the subject of the Croonian lecture, I did not foresee that anything could prevent me from fulfilling my promise; but since that time, what with my state of health, which does not allow-me to be very active, the hurry of official business on account ofthe war, and my brother-in-law, Mr. Home, being employed on the medical staff, I have not had the power of repeating my experiments, and drawing out, to my satisfaction, the many conclusions which are the result of such a power in this humour. " The laws of optics are so well understood, and the knowledge of the eye, when considered as an optical instrument, has been rendered so perfect, that I do not consider myself capable of making any addition to it: but still there is a power in the eye by which it can adapt itself to different distances far too extensive for the simple mechanism of the parts to effect. This power writers upon this subject have been at great pains to investigate and explain. The motion of the crystalline humour forwards and backwards was asserted by some to be the cause, while others supposed in the eye a power to alter its shape, so as to shorten or lengthen its axis, which altered the distance between the crystalline humour and the point of impression ; but we should consider that a part of the eye is itself a refractor, and that if its shape be altered so as to remove the crystalline humour from the point of impression, in order to enable it to bring a distant object to its proper focus on the retina, this effect will be in some degree counteracted by the anterior part of the eye refracting more than before, by being rendered more effec7XVnr thlT T' in fa,Ct» "° P0Wer capable of producing this effect, for the stra.ght muscles, so far from appearing to hav? this PREPARATION FOR THE CROONIAN LECTURE. 295

power, have been even supposed to flatten the eye, and shorten its axis; and it is very possible that the action of these muscles is such as tends to both effects; but, being in opposition to each other, the eye retains its shape, the insertion of these muscles being much more forwards than appears to be necessary for the simple motions of the eye. Further, when we consider that in many animals the shape ofthe eye is unalterable, as in all of the whale tribe, the sclerotic coat being above half an inch thick and composed of a strong tendinous substance ;—that in many fish this coat is composed of cartilage ; and in all birds the anterior part of it is (I believe) composed of bone ;—from all these considerations, I saw no power that could adapt the eye to the various distances of which we find it capable in the human body, unless we suppose the crystalline humour to be varied in figure, which can only be effected by a muscular action within itself. With this idea strongly impressed upon my mind, and finding that in many animals, when the crystalline humour was coagulated, it had a fibrous structure like muscles, I confess it seemed to me to confirm it; but as this might to others appear only conjecture, requiring some proof, I set about such experiments as were best adapted for that purpose. Knowing that in all violent deaths the muscles contract, I supposed the crystalline humour, if muscular, would show signs of this effect; for which purpose I got the eyes of bullocks when removed'from the sockets, the moment the animal was knocked down, and while he eyes were warm the humours were removed." Mr. Hunter had proceeded thus far in the account of his experiments, when he was suddenly, and very unexpectedly, carried off; and as he has left no notes upon this subject, I am unable to make any addition to the account I have already given. Mr. Hunter's laying claim to the discovery of a fibrous structure in the crystalline humour, which had been observed long before, and described by the accurate Leuwenhoek, may appear to require some explanation. The discovery of a fibrous appearance in that humour appertains to Leuwenhoek; but the discovery of an eye in which this structure of the crystalline humour was perfectly distinct, and in which all the circumstances of course and situation could be determined, is due to Mr. Hunter :* and if it should be

* [In this investigation by Hunter of the intimate structure of the crystalline lens we may perceive the continuation of the series of discoveries which, commenced by Leuwenhoek, have, in the hands of Sir David Brewster, produced such unexpected results, and opened so interesting a field for philosophical experiment and teleological speculation with regard to this part of the mechanism ofthe instrument of vision. Notwithstanding the anatomical remarks of Hunter, the observation of Professor Blair (Edinburgh Transactions, vol. iii.), and the experiments of Young, Wollaston, Wells, and Frauenhofer, we still find, even in very recent physiological works, a mere repetition of the simple statement of Paley that the lens consists of concentric layers, which gradually increase in density from the circumference to the centre; and, under the influence of an apt comparison, the principle ofthe construction of the lens is asserted to be the same as that of the compound or achromatic object-glass, and the invention of DoUond to be a repetition, though 296 HUNTER ON THE ANIMAL CECONOMY. tound, by future observation and experiments, that this structure, which is different from any that has hitherto been described, is caan imperfect one, of this the natural type and perfection of a dioptric instrument which is supposed to converge the rays of light into a focus without any dispersion of the rays, and consequently without the production of false colours round the image. Now the fact is that the image given by the eye is not perfect with regard to colours in its ordinary exercise : there is not only dispersion of the ray3 oflight, but the quantity of dispersion has been measured, and the different focal lengths of the eye for red and violet lights have been accurately determined by Young and Frauenhofer; the latter philosopher, indeed, has found it necessary to correct the dispersion of the eye in the construction of his achromatic objectglasses. But to return to the structure ofthe crystalline lens,—thiscomplexand beautiful part consists, according to Sir David Brewster, of innumerable fibres of nearly the same length, each of which tapers from its middle part to its two extremities, like the gores or gussets of a globe. In the lenses of some animals the extremities of all the fibres terminate in two opposite poles ; in others, in a line at each pole, the line at the posterior pole being at right angles to the line at the anterior pole, and all the fibres except a few being bent into the most beautiful curves of contrary flexure. In some lenses the fibres terminate in the lines of a rectangular cross at each pole, the line of the cross at one pole being inclined 45° to the lines at the other pole ; in others, the terminations of thefibrea form more complicated figures. In the largest number of animals the arrangement ofthe fibres is the same at both poles; but in a few, such as the turtle, ihe fibres terminate in a different manner in the two surfaces of the lens. But the structure of each ofthe fibres is still more wonderful than their arrangement. The sides of each fibre are formed with teeth, like those of a watch-wheel, and the teeth of one fibre lock into those of the adjacent ones, apparently to strengthen them and give body to the frail morsel of transparent jelly into which they are so marvellously moulded. In the lens of a cod-fish, four-tenths of an inch in diameter, Sir D. Brewster calculates the number of fibres to be about five millions, and the number of teeth by which the fibres are bound together to be sixty-two thousand five hundred millions; and as every tooth has three surfaces, the number of touching surfaces will be one hundred and eighty-seven thousand jive hundred millions,- and yet this little sphere of tender jelly is as transparent as a drop ofthe purest water, and allowa a beam of light to pass across these almost innumerable joints without obstruct. ing or reflecting a single ray ! With respect to the muscular theory of the lens, and its supposed power of adjusting the eye to vision at different distances, by an alteration of its own form or dimensions, it is hardly necessary to state that these views have derived no support since the time of Hunter, and of Dr. Young, who also entertained the theory ofthe irritability ofthe crystalline fibres. It has, on the other hand, been shown, in the well-attested case of Henry Miles,* that the eye may retain its power of adjustment after the removal ofthe lens. The supposed function ofthe lens, as an achromatic instrument, has been deduced from the structure which it presents in the human body, where the density of the fibrous layers diminishes from the centre to the surface : a structure of which the purpose is undoubtedly to correct spherical aberration; but the lenses of quadrupeds display three different structures of varying density, separated by neutral lines, in which lines a density decreasing outwards passes into a density increasing outwards. This structure is well displayed in the lens ofthe horse; and when the animal has attained a great age the densities of the central and superficial structures have become uniform throughout, while the middle one exhibits a varying density more strongly marked than in the young lens, and exhibiting by polarized light a brilliant yellow colour, like the most perfect films of regularly crystallized bodies. That these structures are intended to correct a See the Croonian Lecture, Phil. Trans., 1802, vol. xcii., p. 8. OF THE ORGAN OF HEARING IN FISHES. 297 pable of producing consequent actions and effects, sufficient to explain the adjustment of the eye to different distances, it will not be considered as a small or unimportant discovery. The melancholy event which has deprived this learned Society of so valuable a member, and which has taken from me so able an instructor, so rare an example, and so inestimable a friend, is too recent to make any apology necessary for the shortness or incorrectness of this account. I thought it due to the memory of my friend that no promise of his, however inadequate I feel myself to performance, should be left unfulfilled ; and the circumstances of distress under which it has been drawn up will procure for me every indulgence from this learned Society. Everard Home. Leicester Square, Nov. 4, 1793. 29. AN ACCOUNT OF THE ORGAN OF HEARING IN FISHES.*

Natural history, having ever been considered as worthy the attention of the curious philosopher, has in all ages kept pace with the other branches of knowledge; and as both arts and sciences have of late years been cultivated to a degree perhaps beyond

spherical aberration or to improve vision cannot be doubted; but the principles are yet to be discovered on which that correction or improvement depends. Meanwhile it is the duty of the physiologist to set plainly before himself, and to offer fairly to his pupils these unexplained or residual phenomena of the theory of vision ; not to hide them beneath an easily comprehended but insufficient illustration. An achromatic lens, though highly desirable, indeed essential to the construction of a good telescope or microscope, is not therefore necessary in the eye : it is well known to be less adapted for the purposes of a camera obscura than a common lens; but the organ of vision has a much closer analogy to a camera obscura than to a telescope. In a telescope, if there be colour, or dispersion of the object-glass, this must be greatly magnified by the eye-piece; and, what is still more essential, there is an eye behind the instrument which takes cognizance of those imperfections, and for whose sake they are endeavoured to be remedied. But there is no eye behind the retina to view in the same manner the image which is thrown upon that membrane. It is well-known that the retina is incapable of transmitting a distinct idea of any spectrum depicted upon it save of that which is situated in or near its axis; the colours of the lateral pencils cannot be seen, and hence it is of no importance whatever to render the image achromatic at a distance from the axis. When we wish to examine an object, or a part of an object, with minute attention, we direct to it the axis of the eye ; and in order to obtain a sensible colourless vision in or near the axis achromatic compensation is not necessary. It is no doubt true that even in this axis there is a non-coincidence of the foci ofthe differently-coloured rays ; but owing to the shortness of the focal distance of the eye, and the low dispersive power of the humours, this non-coincidence of the different foci does no injury to our ordinary vision.] * [Originally communicated to the Royal Society, and printed in the Philosophical Transactions (vol. lxxii., p. 379) for the year 1782.] 298 HUNTER ON THE ANIMAL CECONOMY. what was ever known before, we find that natural history has not been neglected. All the nations of Europe appear solicitous to encourage the study; and in this island it has been pursued with more philosophic ardour than was ever known in any country. It has become an object of pursuit to men possessed of affluent fortune; which they have not only dedicated to the cultivation of this science, but have even risked their health and lives in exploring unknown regions to increase the sources of information, and in settling correspondences everywhere, so as to bring materials into this country that might render it the school of natural history. It is no wonder then that a spirit of inquiry is diffused through almost all ranks of men; and that those who cannot pursue it themselves, yet choosing at least to benefit by the industry of others, are eager to be informed of what is already known. These reflections have induced me to publish this short account of the organ of hearing in fishes; for, although the existence of such an organ is now known to many, it is still a subject of dispute with others whether they possess the sense or not.* Some time before I quitted my anatomical pursuits, in the year 1760,f and went with the army to Belleisle, I had discovered this"

* [Cuvier justly states that the structure of the organ of hearing was better known to some of the ancient anatomists in the class of fishes than even in the human subject. Casserius has given moderately good figures of the serai-circular canals and the ossiculum auditus ofthe pike in his work entitled Pentestesion (p. 224), published in the year 1600. Steno, in the Acta Medica of Copenhagen for 1673, described the internal ear or the Squalus Mustelus, Linn., with tolerable exactness, although without figures. Klein, in his Missus Historiee Piscium permovendse, printed in the year 1740, gives a detailed description and accurate figures of the ossicula of the ear ofthe pike, salmon, trout, umber, marene (Salmo Marsena, L.), herring, cod, dorsch (Gadus callarius, L.), ling, pike-perch, perch, gremille, stickleback, turbot, sole, barbue (Pleuronectes Rhombus, L.), carp, barbel, and many other species of Cyprinus. In 1753, Etienne-Louis Geoffroy, a physician of Paris, presented to the Academy a memoir exprofesso on the organ of hearing in fishes; but this was not printed till the year 1778. He has described generally the ear of the eel, the cod, the pike, the carp, the gardon, (Cyprinus idus, Bio.), the flounder, and the perch ; but he errs in ascribing to certain holes in the cranium the office of a meatus auditonus externus, which they do not fulfil. The fibres annexed to this memoir, Cuvier informs us, were mislaid and lost, and therefore they did not appear in the printed essay. The description of the ear of the rav was given by Geoffroy in a Memoir on the Ears of Reptiles, presented in 1752, and printed in 1 t5o.\ r tlCamper'sresearches on this subject were made in the year 1761: they appeared first in the Haerlem Memoirs for 1762. He afterwards sent a more detailed memoir en the same subject to the Academy of Sciences of Paris in 1/67, which was printed in the • Recueil des Savans Etrangers, t. vii.,' in 1774.

ErM?« "-iVh'fi • le orgfa?of.hearing of the ray-the c°d' the Pike« and the hat whi,h ft 5°reV"i1,,J? elyIV- '" somewhat v4«e. He added but little to naf ciif »?H t?£\ advrc^' eXCePl that he denied t0° g^erally the exterseems ontv to t „ ***?* °f a" °rgan which he terms iensor *«««. ^bich

In the year 1773, in the 17th vol. ofthe Novi Commentary of St. Petersburgh, OF THE ORGAN OF HEARING IN FISHES. 299 organ in fishes, and had the parts exposed and preserved in spirits. In some the canals were filled with coloured injection, which showed them to great advantage, and in others were so prepared as to fit them to be kept as dried preparations.* My researches, in that and in every other part of the animal ceconomy, have been continued ever since that time. I am still inclined to consider whatever is uncommon in the structure of this organ in fishes as only a link in the chain of varieties displayed in its formation in different animals, descending from the most perfect to the most imperfect, in a regular progression.! As in this age of investigation a hint that such an organ existed would be sufficient to excite a spirit of conjecture or inquiry, I was aware that there would not be wanting some men who, whether they only imagined the fact might be true, or really found it to be so, would be very ready to assume all the merit of the discovery to themselves. My attention was more strongly called to this point by hearing, in conversation, that some anatomists in France, Germany, and Italy, had discovered the organ of hearing in fishes, and intended to publish on the subject. I therefore thought that it would be only justice to myself to deliver to the Royal Society a short account of that organ, a discovery of which I had made more than twenty years before. This account I shall reprint here, without adding anything to what I had before written, reserving a more complete examination of this subject for a larger work, on the structure of animals, which I one day hope to have it in my power to publish. _ I do not intend to give a full account of this organ in any one fish, or ofthe varieties in different fishes, but only ofthe organ in general; those therefore who may wish to pursue this branch of the animal ceconomy will think it deficient perhaps in the descrip-

Kolreuter gave some very precise and detailed descriptions and figures ofthe ear, in two species of sturgeon, the common one (Acipenser Sturio, Linn.), and the huso (Acipenser Huso, Linn.). Monro described, better than any of his predecessors or successors, the external ear of the Chondropterygii, in his Anatomy of Fishes, published in 1785. Scarpa denies the external communication in the ray, which Hunter correctly describes in the present memoir.] •' I have injected these parts in other animals, both with wax and metals; which, the bone being afterwards corroded in spirit of sea-salt, make elegant casts of these canals. | The preparations to illustrate these facts* have been, ever since, shown in my collection, to both the curious of this country and foreigners. In showing whatever was new, or supposed to be new, the ears of fishes were always considered by me as one important article.b a [He here alludes to the series of other organs in his collection analogous to those of the ear; and it is interesting to observe these incidental evidences ofthe philosophical tendency in Hunter to view the varieties of structure, which his numerous dissections displayed to him, as modifications of one type, or a graduated and connected chain of varieties.] b [See the Preparations in the Gallery of the Hunterian Museum, numbered from 1560 to 1574 inclusive.] 300 HUNTER ON THE ANIMAL CECONOMY. tive parts. If it was a difficult task to expose this organ in fishes I should perhaps be led to be more full in my description of it, but in fact there is nothing more easy. It may be proper just to observe here, that the class called Sepia has the organ of hearing, though somewhat differently constructed from what it is in fishes.* The organ of hearing in fishes is placed at the sides of the cavity which contains the brain, but the skull makes no part of it, as it does in the quadruped and the bird, the organ being a distinct and detached part. In some fishes, as in those of the ray kind, the organ is wholly surrounded by the parts composing the cavity of the skull; in others it is in part within the skull, or cavity which contains the brain, as in the salmon, cod, &c, the skull projecting laterally, and forming a cavity. The organ of hearing in fishes appears to increase in dimensions with the animal, and nearly in the same proportion, which is not the case with the quadruped, &c, the organs being in them nearly as large in the growing fcetus as in the adult. Neither is its structure, by any degree, so complicated in fishes as in all those orders of animals which maybe reckoned superior, such as quadrupeds, birds, and amphibious animals; but there is a regular gradation from the first of these to fishes. It varies in different genera of fishes; but in all it consists of three curved tubes, which unite one with another ; this union forms in some only one canal, as in the cod, salmon, ling, &c, and in others a tolerably large cavity, as in the ray kind. In the jackf there is an oblong bag, or blind process, which is an addition to these canals, and communicates with them at their union. In the cod, &c, this union of the three tubes stands upon an oval cavity ; and in the jack there are two ; the additional cavities in these fishes appearing to answer the same purpose with the cavity J observed in the ray or cartilaginous fishes, which is at the union ofthe three canals. The whole organ is composed of a kind of cartilaginous substance, very hard or firm in some parts, and in some fishes crusted over with a thin bony lamella, to prevent it from collapsing; for as the skull does not form any part of these canals or cavities, they must be composed of a substance capable of keepino- its form.

* £This if the first announcement ofthe existence of an organ of hearing in the Cephalopoda. It differs from that of fishes in the absence ofthe semicircular canals, and exhibits a simpler stage of structure, consisting of a vestibule, with the nerve, fluid, sacculus, and ear-stone or otolithe. The low-organized Cyclestomous fishes manifest their character as transitional links betwien the invert* brate animals in several parts of their structure, but more especially in the organ of hearing. The myxine has a vestibule, with one canal extended from it. The lamprey shows a further stage of complication, in having two canals continued from the vesubule. All the osseous fishes have three semicircular canals, as described in the; text; and the plagiostomous cartilaginous fishes, as the sharks and rays, exhibit a higher type of structure, in having the internal ear inclosed Z~Z itE f k6 Cramal C3Vily' and in the external communication or meatus which some ot the species present ] f [Esox Lucius, L.] t \_Sacculus vestibuli^ OF THE ORGAN OF HEARING IN FISHES. 301 Each tube describes more than a semicircle, resembling, in some sort, what we find in most other animals, but differing in the parts being distinct from the skull.* Two of the semicircular canals are similar to one another, may be called a pair, and are placed perpendicularly; the third is not so long, and in some is placed horizontally, uniting as it were the other two at their ends or terminations. In the skate this is somewhat different, the horizontal canal being united only to one ofthe perpendicular canals. The two semicircular canals, whose position is perpendicular, are united, forming one canal; at their other extremities they have no connection with each other, but join the horizontal one, near its entrance into the common cavity. Near the union of these canals they are swelled out into round bags' (ampulla)? and become much larger. In the ray kind all these canals terminate in one cavity, and in the cod in one canal, placed upon the additional cavity or cavities, in which there is a bone or bones. In some there are two bones ; and in the jack, which has two cavities, we find in one of them, (the accessory sacculus of the vestibule,)' two bones, and in the other ' (the ordinary sacculus of the vestibule,)' one ; in the ray there is only a chalky substance.f In some fishes the external communication, or meatus, enters at the union ofthe two perpendicular canals, which is the case with all the ray kind, the external orifice being small, and placed on the upper flat surface of the head ; but it is not every genus or species of fishes that have the external opening.J The nerves ofthe ear pass outwards from the brain, and appear to terminate at once on the external surface ofthe enlarged part of the semicircular tubes above described.^ They do not appear to pass through these tubes so as to get on the inside, as is supposed to be the case in quadrupeds ; I should therefore very much suspect

* The turtle and the crocodile have a structure somewhat similar to this ; and the intention is the same, for their skulls make no part of the organ. f This chalky substance is also found in the ears of amphibious animals.a X [Hunter had a drawing made of these orifices in the monk-fish (Squatina Angelus, Dum.), which has been engraved and published in the third volume of the Physiological Catalogue ofthe Hunterian Museum, pi. xxxiii. fig. 1, a.] § [The acoustic nerve comes offfrom the brain, nearly opposite the junction of the sacculus with the vestibule; it sends off from its upper part a filament to each of the semicircular canals : this filament penetrates the ampulla of the canal to which it appertains, and is there lost. Another division ofthe nerve goes to the vestibule, but by far the greatest part of it spreads out into a number of filaments which form a very beautiful apparatus, under the parietes of the sac which contains the large stone.] a [In these it is lodged in a small blind sac, communicating with the vestibule, and representing the cochlea in a rudimental state. In the ray also, the vestibule, after receiving the orifices ofthe semicircular canals, opens into a large oval sac, which gives off two appendages, one anterior, the other posterior; this sac is analogous to the rudimental cochlea in reptiles, as is also the sacculus vestibuli in the osseous fishes.] 27 302 HUNTER ON THE ANIMAL CECONOMY. that the lining of the tubes in the quadruped is not nerve, but a kind of internal periosteum. As it is evident that fishes possess the organ of hearing, it becomes unnecessary to make or relate any experiment made with living fishes, which only tends to prove this fact; but I will mention one experiment, to show that sounds affect them much, and is one of their guards, as it is in other animals. In the year 1762, when I was in Portugal, I observed in a nobleman's garden, near Lisbon, a small fish-pond full of different kinds of fish. The bottom was level with the ground, the pond having been made by forming a bank all round, and had a shrubbery close to it. Whilst I lay on the bank observing the fish swimming about, I desired a gentleman who was with me to take a loaded gun and fire it from behind the shrubs. The reason for desiring him to go behind the shrubs was, that there might not be the least reflexion of light. The moment the report was made the fish seemed to be all of one mind, for they vanished instantaneously, raising a cloud of mud from the bottom. In about five minutes afterwards they began to appear, and were seen swimming about as before. Mons. Geoffroi, who has written on this organ, considers the ray as in the class of reptiles, and with that idea has examined their organ of hearing. He is by no means clear in his description, so that it is almost impossible to follow him ; yet it is but doing him justice to allow that he has discovered what is analogous to the three semicircular canals in other animals, together with their union into one cavity. He mentions the chalky substance contained in that cavity, and also the nerves; but it is by no means clear that he was acquainted with the external opening which leads to these canals. He says, " The entrance of the organ of hearing (by which one would suppose he means the meatus auditorius externus) is not easily discovered ;;' but that which he describes does not correspond with the real situation of the external communication; we may therefore reasonably conclude that he is describing something else. He is not more clear in his mode of reasoning on the application of the parts to produce the sense of hearing. He observes that the organ of hearing is very imperfect in this species of animals, but supposes this to be compensated by the medium in which they live, and by which sound is conveyed to them, being more dense than that of the air, by which sound is communicated to animals living on the land; and of this idea he is certainly the author. Mons. Geoffroi cannot indeed be said to have given a perfect account ofthe organ of hearing in fishes, yet on the whole he should be considered as a discoverer; for though he only made his observations on the ray, as belonging to the class of reptiles, yet as it may be properly considered of the fish kind, he has a just claim to that credit. Had 1 formerly been acquainted with this author's researches and pretensions, I should not have claimed that to which I had not a prior right: nor should I have held the discovery of the external communication alone, an object of consequence enough to induce me to dispute the honour with Mons. Geoffroi. OF ABSORPTION BY VEINS. 303

In looking over the works of the different authors who have treated of the organ of hearing in fishes, I find from a passage in Willoughby,* who published prior to Mons. Geoffroi, and indeed is quoted by him, that my claim, even to the discovery of the external opening, is not so strong as I believed it to be, as he mentions an external orifice in the skate contiguous to what he supposes the organ of hearing in that fish. If what he alludes to is reaily the external opening of the ear, it gives him a prior claim to the discovery of that part of the organ, although from his account, he does not seem to have been acquainted with the organ itself; for, as in describing the external ear of the thornback, he has evidently mistaken the nose of it, of which he gives a tolerably full account, it is very obvious that he was ignorant of the opening into the ear.f Although Professor Camper published an account of the organ of hearing in fishes so late as 1774, he did not seem at that time to have been acquainted with the external opening of the ear in the ray. After giving a description of the organ of hearing in the pike, he makes some general observations on the similarity of this organ in other fishes, but excepts the shark and ray.J This exception we might suppose alluded to the auditory canal, but further on he explains what is meant by this exception, and does not mention the external opening in the ray, from which we may fairly conclude that he was not acquainted with it.§ 30. OF ABSORPTION BY VEINS.||

[Dr. Hunter introduces the account of his brother's experiments on this subject as follows.]

In both my courses of the winter 1759-60, I went so far as to say, I believed that the red veins did not absorb; and gave my rea-

• Willughbeii Historia Piscium, Oxonii 1686, lib. iii. cap. viii. f Lib. iii. cap. xiv. X " II est tres-vraisemblable que toutes les autres especes de poissons, tant malacopterygii qu' acanthoplerygii, aussi-bien que les branchiostegi & les ckondropterygii d'Artedi, a l'exception des squales & des raies, ont l'organe de l'ouie construit a peu pres de la meme facon ; je n'excepte pas l'esturgeon, quoiqueM. Klein, ibid, ait donne la description du conduit auditif,page 19, figure A, Tab. 2. b; ce poisson etant rare parmi nous, je n'ai eu occasion de l'examiner qu'une seule fois sans avoir trouve ce conduit." Memoirs Etrangers de I'Academie des Sciences, 1774, torn. G, page 190. § " Au contraire, les chiens de mer, lesgafeisdeRondelet & les poissons qu'il a decrits, lib. XII.; les squalls d'Artedi & les raies, ont bien l'organe a peu pres de la meme composition, mais il est enferme dans une cai3se tout osseuse ou cartilagineuse, ce qui ne fait pas une difference essentielle; ils entendent done comme le eglefins, les morues, les baudroyes & les brochets, en un mot comme tous les autres poissons non amphibies: M. Geoffroi s'est trompe en comparant leurs organes avec celui de reptiles, tels que la vipere, les lezards, &c. qui entendent le son comme les quadrupedes, les oiseaux & les amphibies aquatiques, savoir par le moyen de l'air & d'un tambour, comme j'ai dessein de le prouver .dans une autre occasion." Memoires Etrangers de I'Academie des Sciences, 1774, torn. 6, page 190. || [Medical Commentaries, Part I., p. 39.] 304 HUNTER ON THE ANIMAL CECONOMY. sons for thinking so; and in different parts of my lectures I used to treat of the transudation and absorption of fluids in animal bodies in the following manner: " I have often considered with myself how the interstitial fluid gets into the smaller and greater cavities of our bodies; how the water of an anasarca, for instance, gets into the cellular membrane. The common opinion, I think, is, that there are everywhere exhalant arteries, which open and terminate on the superficies of such cavities, and throw out the watery fluid which they contain. But for my own part, I cannot help believing that it is entirely by transudation through the coats or sides of the vessels. My reasons for thinking so are these : "First, so far as I can find, all the arguments of the latest and best anatomists, taken from injecting the arterial system in dead and living bodies, only prove that a thin fluid passes readily from the arteries into the interstices of parts. They do not prove the existence of exhaling branches more than they prove transudation. " In the second place, the phenomena of injections, so far as I have been able to make observations, agree better with the notion of transudation than with that of exhaling arteries. I have had great experience of injections, and I have made experiments with all sorts of fluids injected into the arteries and veins of dead bodies. I have always observed that subtile and penetrating fluids pass with ease from the arteries into the cavity of the intestines, and into the cellular membrane in any part of the body: such fluids are water, gum-water, whites of eggs strained, glue, isinglass dissolved in water or spirits, any fluid oil, melted butter or axunge, &c. But when these fluids were coloured with vermilion I always observed that none of the vermilion passed out of the arterial system but when there were manifest appearances of extravasation and rupture of the vessels: I never observed vermilion pass into the cavity of an intestine from the mesenteric arteries, without seeing a hundred ruptures and extravasations in the villi of the gut. All this looks as if the fluid oozed through the coats rather than was poured out by the branches of arteries. " In the third place, I have observed that the cellular membrane is not so immediately filled by injecting the arteries ; it requires some time, and I have plainly seen, when I have let an injected part he by a little while, that the cellular membrane became gradually more loaded as the arterial system became more empty: a strong argument, in my mind, that it got out of the arteries by transudation. " In the fourth place, water and even red blood soaks through all our vessels and membranes in dead bodies; as you may see by steeping the apex of a heart well washed, or the convolution of a piece of fresh intestine in clear water; in both cases the water will become bloody. " But still it is said that in all these cases the fluids pass by fine exhaling vessels, though these vessels cannot be seen. To this I answer that if our interstitial fluid was of a strong marked colour, OF ABSORPTION BY VEINS. 305 we should then by dissection be able to observe whether it was poured out by small arteries, or whether it soaked through the natural pores in the coats of vessels. Now, very fortunately for us in this dispute, there is one such fluid in the body : it is the bile. Its colour is pretty deep, and very different from anything that lies near the gall-bladder. No man can have opened any number of bodies without allowing that the gall does pass through all the coats of the gall-bladder, and pervades the substance of the neighbouring parts, not by exhaling nor by inhaling vessels, but by manifest transudation or soaking. " It might be asked, why the red blood does not transude through the vessels in living bodies ; for I think it certainly does not. In answer to this it may be said that our fibres and vessels have perhaps some degree of tension and firmness in life which they lose with life; and it must be observed too, that in proportion as the blood purifies it becomes thinner; whence we see, in opening a putrid body, all the cavities more or less filled with a bloody water, and all distinction of colour in the muscles and cellular membrane quite lost. But what I suppose to be the principal reason that red blood does not transude through the vessels in living bodies is its glutinous quality, its thickness while it is equally mixed up with its coagulating part. That part coagulates as certainly as the blood stagnates even in living bodies ; and when the universal stagnation happens in death, this part of the blood collects itself into irregular polypi and coagulations all over the body, and the rest of the blood is no longer the thick viscid fluid it was before, but rather a bloody serum, that will ooze through all the vessels and membranes." Such were my notions of the source of our interstitial fluid. With regard to its absorption, I was of opinion that Nature had provided a system on purpose, viz., the lymphatics. I considered these vessels and the lacteals as an appendage to the venal system, by which the stores were brought in for supplying the circulation; and the glands and secretory vessels all over the body I considered as an appendage to the arterial system, by which the proper separations were made, and the redundancies thrown off. My only doubt was whether the veins did or did not absorb a certain quantity, especially in the intestines. From my own observations on injections I should have concluded that they did not, and that there was no passage for liquors between an intestine and the mesenteric veins otherwise than by transudation. But authors of the best credit had given such arguments and experiments in favour of absorption by veins, that I dared not, even in my own mind, determine the question. At this time my brother was deeply engaged in physiological inquiries, in making experiments on living animals, and in prosecuting comparative anatomy with great accuracy and application. It is well known that I speak of him with moderation when I say so. He took the subject of absorption into his consideration, and 27* 306 HUNTER ON THE ANIMAL CECONOMY. from all his observations was inclined to believe that in the human body there w?as one, and but one, system of vessels for absorption. He knew so well that many things had been asserted by one person after another which were not true, that so many mistakes had been made from inattention, so many errors introduced from other causes, that he could easily suppose the veins might not perhaps absorb, after all the demonstrations that had been given of the fact; and therefore was determined to see how far this point could be cleared up by plain experiments and observations. With that intention he made the following experiments, in my presence and in the presence of a number of gentleman, who all of us assisted him, and made our own observations upon what passed before us. ] shall quote the experiments from him, and can bear testimony to the fairness with which they were made and with which they are here related. " Animal First.—Experiment I. On the 3d of November, 1758,"* says he, " I opened the belly of a living dog. The intestines rushed out immediately. I exposed them fully; and we observed the lacteals filled with a white liquor at the upper part of the gut and mesentery; but in those which came from the ileon and colon the liquor was transparent* " I tied up the mesenteric artery and vein that was going to about half a foot of intestine, and put a tight ligature upon the upper part of the intestine, including a little of the mesentery ; then emptied that part of the gut by squeezing it downwards, and put a similar ligature upon the lower part ofthe gut. In the next place, I made a small hole in the upper end of this part of the gut, and by a funnel poured in some warm milk, and confined it by making a third ligature upon the gut close to this hole. These ligatures prevented the circulation of blood in this part of the bowel. Lastly, I punctured the vein beyond the ligature that had been made upon the mesenteric vessels, and by gently stroking with the end of the finger soofn emptied it of its blood. "Experiment II. I immediately'after this made the same experiment, and in the same manner, on a part of the intestine lower down, where the lacteals were filled with a transparent liquor. " In the first experiment the lacteals continued to be filled with a milky or white fluid: in the second, the lacteals, which before contained only a transparent lymph, were presently filled with white milk. "In both these experiments we could not observe that the least white fluid had got into the veins. After attending to these appearances a little while, I put all the bowels into the abdomen for some time, that the natural absorption might be assisted by the natural warmth; then took out and examined attentively the two parts of the gut and mesentery upon which the experiments had been made:

* In presence of Doctors Clayton, Fordyce, and Michaelson, and Messrs. Blount, Jones, Churchill, and Richardson. OF ABSORPTION BY VEINS. 307 but the lacteals were still filled with milk, and there was not the least appearance of a white fluid in the veins ; on the contrary, what little blood was in them was just as thick and as deep-coloured as in the other veins, and when squeezed out from them coagulated as the blood of other veins. " Experiment III. I tied up and filled another piece of the intestine with milk in the same manner, but did not make a ligature upon the mesenteric vessels, leaving a free circulation in the part. We looked very attentively at the colour of the blood in the vein of that part, both with our naked eyes and with glasses: we compared it with that in the artery and in the neighbouring veins, but could not observe that it was lighter-coloured, nor that it was milky, nor that there was any difference whatever. Experiment IV. Lastly, we took that part of the gut which was filled with milk in the first or second experiment, and squeezed and pressed it very gradually, in order to see whether any milk would by these means pass into the empty mesenteric veins. This we did gradually, with more and more force, till the gut at last burst; but still there was not the least appearance of anything milky in the veins. "Animal Second.—Experiment I. November 13, 1758,* I opened the abdomen of a living sheep, which had eat nothing for some days, and upon exposing the intestines and mesentery we observed the lacteals were visible, but contained only a transparent watery fluid. I made a hole in the intestine near the stomach, and by a funnel poured in some thin starch, coloured with indigo, so as to fill several convolutions ; then tied up the whole in the gut, and put all the bowels into the abdomen for some time. Upon taking them out after this we observed all the lacteals of that part filled with a fluid of a fine blue colour/)- We thought at first that the * In presence of Doctors Wren, Fordyce, and Michaelson, and Messrs. Blount, Tickell, Churchill, Paterson, and Skeette. f [Martin Lister, in 1682, injected twelve ounces of the tincture of indigo into the small intestines of a living and fasting dog. At the time of the experiment there " was not the least appearance of lacteal veins in the mesentery :" after full three hours the mesentery was examined, and many lacteals were found of an azure colour; and some of the biggest of them being cut, a thick bluish chyle was seen to issue forth. (Phil. Trans., vol. xiii., p. 9.) The conclusion which Lister drew from this experiment with reference to the power of the lacteals to absorb extraneous matters along with the chyle, was opposed in his time by some writers, and it was stated " that people may be deceived with blue tinctures, for this is the natural colour of these lacteals when they are almost or altogether empty." See Phil. Trans., No. 275, October, 1701, p. 996. In order to try the value of this objection, Dr. Wm. Musgrave instituted the following experiments: " Feb. 1G82-3. I injected into the jejunum of a dog, that had for a day before but little meat, about twelve ounces of a solution of indigo in fountain water, and after three hours, opening the dog a second time, 1 observed several of the lacteals of a bluish colour, which, upon stretching of the mesentery, did several times disappear, but was most easily discerned when the mesentery lay loose; an argument that the bluish colour was not properly ofthe vessel, but of the liquor contained in it. " A few days after this, repeating the experiment in another company, with the 308 HUNTER ON THE ANIMAL CECONOMY. blood in the veins of this part was of a darker colour, but on comparing it carefully with that in the other veins it was manifestly the same. " Experiment II. I opened a vein upon this part of the mesentery, and catched a table spoonful of its blood. I set it by to congeal and separate into its coagulum and serum. On the next day and the day after that I examined the colour of the serum, but it had not the least bluish cast. " Experiment III. I fixed an injecting pipe in an artery of the mesentery, where the intestine was filled with the blue starch, and tied up all communications both in the mesentery and intestine (as in Animal First, Exper. I.), but left the corresponding vein free; then I injected warm milk by the artery till it returned by the vein, and continued doing so till all the blood was washed away, and the vein returned a bright white milk. This was done with a view of seeing if the milk in the vein acquired any bluish cast, but there was no perceptible difference between the arterial and venal milk. " Experiment IV. After this I opened the vein with a lancet, and discharged most of the milk, then put a ligature upon both the artery and vein, and waited some time to see if they would fill, but they did not, nor did the remaining contents of the vein acquire the least bluish cast. Then I opened the gut at this part, but we

solution of stone-blue in fountain water, and on a dog that had been kept fasting thirty-six hours, I 6aw several of the lacteals become of ^perfect blue colour within very few minutes after the injection : for they appeared so before I could sew up the gut. At about the beginning of March following, having kept a spaniel fasting thirty-six hours, and then syringing a pint of a deep decoction of stone-blue with common water into one ofthe small guts, and after three hours opening the dog again, I saw many of the laeteals of a deep blue coliur. Several of them were cut, and afforded a blue liquor (some of the decoction), running forth on the mesentery. "After this I examined the ductus thoracicus (on which, together with other vessels near it, 1 had upon my return made a ligature), and saw the receptaculnm chyli and that ductus of a bluish colour, not so blue indeed as the lacleals, from the solution mixing in and near the receptaculum with lyrnpha, but much bluer than the ductus uses to be, or than the lymphatics under the liver (with which I compared it) were. I trusted not my own eyes in any one of these experiments, but in each of them had the company and assistance of several physicians, who all agreed with me as to the colouring of the lacteals." (Phil. Trans., No. 275, October, 1701.) The same objection, the force of which was invalidated by the experiments of Musgraye, has been in recent times urged against the experiments of Hunter, related in the text; but it is obvious that it cannot apply where care is taken to observe the colour or appearance of the empty or transparent lacteals before throwing the coloured fluid into the intestine, and to contrast that appearance of the lacteals with the colour which they present after the experiment has been performed. Now this precaution Hunter invariably adopted. With reference to the experiments on the lacteals recorded in the early numbers ofthe Philosophical Transactions, it may be observed that they differ from those of Hunter in the absence of observations and modifications which the latter physiologist combined with them, in order to test the share which the veins might take in the absorbing processes;—a question which does not appear to have occupied the attention of either Lister or Musgrave.] OF ABSORPTION BY VEINS. 309 could not observe any appearance of the milk having got into the cavity ofthe intestine. " Experiment V. I filled another part of the intestine with milk. All that we observed after doing this was, that the lacteals became fuller, though not of a white colour, and the veins remained of the same complexion. "Experiment VI. I fixed a pipe into the vein of the mesentery, and injected milk towards the intestine, to see if any would pass into the cavity of the gut; but presently innumerable extravasations happened, so that the experiment was fruitless. "Experiment VII. I fixed a pipe into an artery, and tied up the vein and all the communications; then injected milk for some time into the artery till the vein became quite turgid and tight; this was continued for some little time, and with as much force as we thought the vessels would bear without bursting; then we opened the intestine at that part, and there was no appearance of milk in its cavity. "Experiment VIII. I took a piece ofthe intestine that was quite empty and clean, and filled it with warm water. The returning blood in the vein of this part appeared not at all diluted or thinner than in the other veins. Then I tied up the artery and all the communications, and attended to the state of the vein for some time; it did not grow more turgid, nor did its blood become more watery, nor was there any appearance whatever of the water's having got into the veins. "The animal was quite alive all the time of our making these experiments and observations, which lasted from one o'clock till half an hour after three. I chose a sheep rather than a dog, both because the animal was much larger, and therefore its mesenteric vessels were fitter for being easily injected, and besides, because it is much more patient and quiet. These advantages we were all sensible of when we made the experiments. "Animal Third.—June 22d, 1759. We repeated most of these experiments on another sheep, to see if the effect would be the same, but in this animal the viscera were diseased, inflamed, and thickened in most parts, so that the experiments were much less successful, less satisfactory, and conclusive. After injecting milk into the mesenteric artery for some time, and allowing it to return by the vein, we opened that part of the intestine which had been previously emptied, and found in it a watery fluid of a whitish cast, as if a few drops of milk had been mixed with it. "Animal Fourth.—In July, 1759,* I repeated most of the experiments related in article Animal Second, upon another sheep. The effect of all of them was so nearly the same that I need not be particular. " I shall only observe, that when the intestine was filled with starch-water and indigo, and milk injected by the artery till the * In presence of Doctors Macaulay, Ramsey, and Michaelson, and Messrs. Edwards and Tomlinson. 310 HUNTER ON THE ANIMAL CECONOMY. vein was washed clean of blood, and a ligature put upon the artery and vein, so as to leave them about half full of pure white milk, after waiting more than half an hour we could not observe that the vein was in the least more filled or turgid, nor had the milk in the veins acquired the least of a bluish cast, not even in the small veins upon the gut itself, where we should suppose the absorbed liquor must have been apparent if any had been taken up by the veins from the cavity ofthe intestine. "After the animal was dead I blowed into a mesenteric vein, and the air found a passage into the cavity of the gut; though in making the experiment when the animal was alive, I could not force the milk by injection from the vein into the gut. " Animal Fifth.—If any animal could be supposed a fitter subject for such experiments than a sheep, it would be an ass. He is not so large nor so strong but that he may be managed; he is patient in the greatest degree ; his mesentery and vessels being larger, it is so much more easy to fix injecting pipes, make ligatures, &c.; and, what is a very great advantage in making such experiments, his mesentery is very thin, without fat, so that the vessels are conspicuous and distinct. Hence it is easy to separate the artery from the vein, to fix pipes, to tie up anastomosing vessels by a needle, &c. " Therefore I got an ass, and on the 24th of August, 1759,* put him upon his back in an open garden, and tied him fast to four stakes drove into the ground, then opened his abdomen, &c. " Experiment I. I poured a solution of musk in warm water into a piece of the intestine, and confined it there by two ligatures. In doing this the animal struggled, and a little of the liquor was spilt upon the outside of the intestine and mesentery. "After waiting a little while, I opened with a lancet some lacteals of this part, which were full of a watery fluid, and catched a little of their contents in a small spoon. It smelled strongly ofthe musk, and though it could hardly be doubted that the musk had been taken up from the intestine by absorption, yet as some ofthe musk-solution had been spilt upon the external surface ofthe parts, and as it was impossible to collect the lymph from the lacteals without resting the edge of the spoon upon the mesentery, the smell ofthe spoon might be owing to that circumstance. "After this I wiped a vein upon the mesentery very clean, and opened it with a lancet: a gentleman who had kept out of the way of the musk came immediately with a clean spoon, and filled it from the stream of blood without touching any part of the animal, and carried it directly off, but it had not the least smell of musk. " Experiment II. We poured some starch-water, made very blue with indigo, into a part of the gut in the same manner as in some of the former experiments, tied the vein and artery of this part, then punctured the vein close to the ligature, and pressed out almost * ?n Presence of Doctors Macaulay and Michaelson, and of Messrs. Edwards, White, and Gee. OF ABSORPTION BY VEINS. 311

all the blood; then tied up the empty vein, and put all into the cavity ofthe belly for a quarter of an hour. After that we examined the part, found the lymphatics very turgid, as the fluid could not pass through them towards the thoracic duct on account of the ligatures made upon the mesenteric vessels; but we found the veins of this part empty, except indeed that a little blood had got into them from the neighbouring vessels, which, from the appearance, had evidently passed the ligatures tied round the ends of the gut, a circumstance which it is very difficult to obviate. " Experiment III. I next repeated the Third Experiment of Animal Second exactly in the same manner, and precisely with the same effect. "Experiment IV. Then I repeated the Fourth Experiment of Animal Second, and the effect was still the same. " N. B. It may not be amiss to observe that the lacteals continued to absorb the bluish liquor all this time, even at the part upon which this Fourth Experiment was made, where the nerves must necessarily have been tied up with the artery. "Experiment V. I squeezed a piece of the intestine so as to empty it as entirely as well might be, then tied up all the lateral communications of the vessels, and injected warm milk into the mesenteric vein till it returned by the artery, and continued this operation for some time after all the blood was washed out. Then I opened that part ofthe intestine through its whole length, and found it quite empty. " I made this experiment again upon another part of the intestine, in the same manner, and exactly with the same success." Here is a new doctrine proposed in physiology, viz., that the red veins do not absorb in the human body. The fair inquirer after truth will be convinced, by the observations which occurred to me, that the common opinion, that they do absorb, is supported by some proofs that are at least doubtful or equivocal, and that the other opinion is not without plausibility; and he must allow that my brother's experiments render it highly probable. [In attempting to form a correct estimate of the merits of Mr Hunter as a discoverer in reference to the absorbent system, it becomes necessary, in the first place, to distinguish between the discovery of the vessels themselves, whether lacteals or lymphatics, and that of their functions and anatomical relations to the other parts of the vascular system. With respect to the Mammalia, it is scarcely necessary to observe that the existence of both lacteals and lymphatics had been determined in that class long before the time of Dr. William Hunter. The discovery of the lacteals by Asellius was first made publicly known in 1628 ; and that of the thoracic duct by Pecquet in 1651. In 1652 our countryman Joliff, having placed a ligature round the spermatic cord, saw, upon squeezing the testicle, that certain vessels, which he termed « vasa lymphatica,' became turgid ; he did not, however, 312 HUNTER ON THE ANIMAL CECONOMY. himself publish this observation, and it might never have seen the light, had not, in the meanwhile, the attention of the anatomical world been drawn to the lymphatic vessels by Bartholinus, an illustrious philosopher of Denmark, in 1651, and by Rudbeck, a Swede, and professor at Upsal, in 1652. In 1668, M. Louis de Bills appears to have traced lymphitic vessels from the 'jugular glanduls' of a dog to the thoracic duct. See Phil. Trans., iii. (1668), p. 791. But the lymphatic absorbents had never been distinguished as a system, either anatomically or physiologically, from the capillary vessels. Noquez, who of all anatomists before the Hunters, had dwelt more particularly on the lymphatics, and who was cited by some of the contemporaries of the Hunters as having anticipated them in this department of their anatomical labours, divided the lymphatics into four classes: one of these corresponded with the capillary blood-vessels of modern physiologists ; a second, with the serous exhalant arteries ; a third, to the veins corresponding with these arteries, and to which Noquez gave the name of * conduits absorbents,' until they became large enough to be sensible to the naked eye, and began to receive red blood. His fourth class of lymphatics includes the absorbent vessels of the Hunters, and were described by Noquez as ending in the receptaculum chyli, the thoracic duct, the vena cava, and the vena portarum. It is therefore obvious that the Hunterian doctrine ofthe absorbent system was in no way anticipated by Noquez, who appears to have been a mere compiler, undistinguished by any original research, and whose anatomical treatise was professedly an improvement upon Keill's. With respect to the extension of our knowledge of the condition of the lymphatic system in the human subject, it appears that Mr. Hunter greatly contributed to this important branch of anatomy. Dr. Hunter describes one of his preparations, which showed the lymphatic vessels extending from the ham upwards to the thoracic duct, as well as the inguinal and lumbar glands, and the larger lacteals at the root of the mesentery, the receptaculum chyli, or what is so called, all finely filled with mercury. He acknowledges his brother's discovery in 1753 or 1754, that the lymphatic glands, and the lymphatic vessels going from them, could be filled uniformly by pushing a pipe into their substance : and states it to have been Mr. Hunter's intention to have traced the lymphatic vessels all over the body, and to have given a complete description and figure of the whole absorbing system. This work was unfurtunately arrested by a very indifferent state of health, the effect of too much application to anatomy, which obliged Mr. Hunter to be much in the country. It was afterwards, as is well known, ably accomplished by another ornament ofthe Hunterian school, the celebrated Cruikshank. When the question of the office of the lymphatics first began to be agitated, one of the arguments against their being the exclusive agents of the absorbing processes was founded on their supposed absence in the oviparous vertebrata.* The discovery of this system of vessels in birds

* [" Lacteal vessels have not as yet been certainly observed in birds, or in the more common fishes, nor in general in the animals called oviparous ; and, from a considerable number of experiments I have made, I am convinced they want the lymphatics as well as the lacteal vessels." Monro, Observations Anatomical and Physiological. 8vo. Edinb., p. 57, 1758. OF ABSORPTION BV VEINS. 313 formed, therefore, no unimportant support to the views of Dr. William Hunter, and to this discovery Mr. Hunter is justly entitled. Mr. Hewson, who first published on the lymphatics of birds, and who discovered their lacteal absorbents, acknowledges that " it is but doing justice to the ingenious Mr. John Hunter to mention here that these lymphatics in the necks of fowls were first discovered by him many years ago." (Phil. Trans., 1768, p. 220.) And it appears from Dr. Monro's reply to Mr. Hewson, that this discovery of Mr. Hunter's had been communicated to Dr. Cullen by Dr. George Fordyce, and had materially influenced Dr. Monro's opinions respecting the absorbent system. Mr. Hewson also informs us, that prior to his own publication on the Absorbent System of Amphibia, Mr. Hunter had discovered and demonstrated to him the chyle, and we must suppose the lacteal vessels, of a crocodile. With respect to the absorbent system in fish, the discovery of this must be awarded to Mr. Hewson. As early as 1701 experiments had been instituted with a view to discover the function of the lacteal vessels, indicated of old by Erasistratus, and rediscovered by Asellius. Martin Lister and Musgrave satisfied themselves that coloured matter was taken up by these vessels which they termed lacteal veins, from the intestine.* Nevertheless, until the observations and experiments of the Hunters, the lymphatics generally were believed by Haller and other physiologists to be simply continuations of capillary or lymphatic arteries, and they were supposed to have no other function than to carryback into the circulation the serum or lymph of the blood. Dr. William Hunter having observed that he could not inject the lymphatics from the arteries excepting the injection were extravasated in the cellular substance, but that he could readily inject the lymphatics both from the common cellular substance and that which assists in forming the parenchyma of the glands, as the testis, spleen, &c.; observing also that the course of the venereal poison, when introduced into the system, indicated that it was carried along by the lymphatics, affecting the inguinal glands when applied to the glans penis or prepuce, and in like manner affecting the glands of the armpits when applied to the hands, and the cervical glands when communicated by the lips ; perceiving also the close analogy of the lymphatics to the lacteal absorbents, in their valvular structure and mode of termination ; he concluded from all these circumstances that they had an analogous function ; that they were not reflected capillary arteries, but originated from all the interstices and cavities of the body, forming the absorbing vessels of the general system, as the lacteals were allowed to be of the alimentary canal. This doctrine was supported by the experiments of John Hunter given in the text, which were first published in 1762, while he was abroad with the army at Belleisle, by his brother, Dr. William Hunter, in the Medical Commentaries. It would seem, however, that Mr. Hunter did not consider these alone as sufficiently conclusive to be submitted to the public, since he left them in manuscript with his brother, who made use of them, four years afterwards, in the controversial essay with the Monros, while John

* [See Experiments for transmitting Blue-coloured Liquor into the Lacteals. Musgrave, Phil. Trans., vol. xii. p. 996. Experiments for altering the Colour of the Chyle in the Lacteal Veins, by M. Lister, Phil. Trans., vol. xiii., p. 6. Powdered Blues pass into Lacteal Veins, ibid., vol. xxii., p. 819.] 28 314 HUNTER ON THE ANIMAL CECONOMY. was abroad with the army at Belleisle. They were unaccompanied by any additional proof or observations, but were considered by Dr. William Hunter as being decisive in depriving the veins of the power of absorbing altogether. Mr. Hunter, however, continued these experiments in other classes, as is shown in the following manuscript note in the possession of Mr. Clift. " The experiments upon the bird, to ascertain whether the mesenteric veins absorbed or not, were nearly the same with those made upon the ass, in 1758, with musk, as also with spirits of wine; and although in those researches I did not discover the lacteals in the bird, yet I discovered that the red veins in the mesentery in them most probably did not absorb, because I never could find any of the liquors which had been thrown into the gut mixed with the blood ofthe veins ofthe mesentery; and which I look upon as one of the first steps towards proving another system." Subsequent experiments, especially those of Tiedemann and Gmelin, Meyer and Segalos, have shown that a power of absorption cannot be denied to the veins ; yet the admission of this power, (which must be granted on anatomical grounds to the veins of all invertebrate animals, and to some parts, probably, of the vertebrate, as the eye and the brain,) does not invalidate or diminish the credit due to those experiments and enlarged conceptions of the uses and anatomical relations ofthe lymphatics, by which the true function of these vessels was ascertained. I say the true function ; for though it be admitted that the veins absorb, yet every physiologist,*—with the exception of one who has held the sympathetic nerve to be no nerve, and who, in the nineteenth century, denied that reptiles and fishes had lymphatic vessels,—allows that absorption, and the effecting a certain change in the nature of the absorbed liquors are the only functions which the lymphatic vessels perform. I would here for the present willingly leave the subject, but that I feel it incumbent upon me, in regard to the character of an author whose works have exercised so great and salutary an influence over the surgical profession, to show that the charge of imperfection and negligence* which has been cast upon the Hunterian experiments,—whose want of exactness, according to M. Majendie, can only be excused by the rude state in which the art of physiological experiment was at the period when they were made,—rests entirely on the culpable oversight of the accuser. In relating one of his experiments, Mr. Hunter states : " Nov. 13,1758, I opened the abdomen of a living sheep, which had eaten nothing for some days ; and upon exposing the intestines and mesentery we observed the lacteals were visible, but contained only a transparent watery fluid." Is it conceivable that any succeeding physiologist would have ventured, in his commentary on Mr. Hunter's experiments, to object to them, "be-

* [" L'etat d'imperfection ou £tait Part des experiences physiologiques k l'e'poqueoil J. Hunter a fait celle-ci peut seul excuser ce celebre anatomiste de n'avoir pas aenti combien il y manque de circonstances importantes pour que Ton puisse, en la supposantexacte, en tirer quelques consequences. En effet, pour que cette experience put etre de quelque utilite il faudrait savoir si l'animal etaitajeUn lorsqu'on l'a ouvert, ou s'il etait dans le travail de la digestion ; il aurait fallut examiner l'etat des lymphatiques au commencement de l'expe'rience ; etaient-ilsou n'etaient-ils pas pleins de chyle," &c. And again, " Hunter fait une fausse theorie sur l'une de fonctions les plus importantes de la vie, il t'etaie a peine de quelques experiences inexactes, et dans, tous lescas insuffisantes."—Precis Elementaire de Physiologic (3me ed.) tom.ii. pp. 199, 201.] 6 K '' OF ABSORPTION BY VEINS. 315 cause the experimenter had neglected to notice whether the animal experimented on was full or fasting; or whether the lacteals were or were not distended with chyle ?" To give a colour to this objection, all reference to the experiment above quoted is avoided in the ' Precis Elementaire;' but even in the very experiment of which M. Majendie gives a mutilated version, Mr. Hunter expressly premises that, " having exposed the intestines fully, he observed the lacteals filled with a white liquor at the upper part of the gut and mesentery; but in those that came from the ileon and colon the liquor was transparent." In the herbivorous quadruped, the sheep, in which Mr. Hunter employed starch as the menstruum of the indigo, the transparent watery nature of the contents of the lacteals was especially noted before the colouring material was thrown into the intestines: they were afterwards observed to be filled with a fluid of a fine blue colour. And yet M. Majendie (ibid., p. 210) would have us believe that no alteration had been observed ; that the lacteals were of the same blue colour before the injection of the indigo and starch had been performed as after. Whether, however, the coloured matter had passed into the lacteals or not, it could not, by the most careful and varied experiments, be detected in the veins. Great precaution was taken to ascertain that fact. Since the natural colour of the blood rendered it difficult to perceive a change of hue, the contents of the veins were collected and suffered to coagulate, in the expectation of the serum manifesting the presence of the indigo; but it had not the least bluish tint. Warm milk was then made to circulate from the artery into the vein; and it might surely have been expected, especially if the doctrine of nonvital imbibition advocated by M. Majendie were true, to have then had a trace ofthe coloured contents of the intestine in the venal milk; but no such result took place. The experiment upon the ass, in which the odour of musk was present in the chyle, but not in the venous blood, is not referred to by M. Majendie. In making these comments it is by no means intended to uphold the infallibility of Mr. Hunter; but it may be safely averred that a candid and careful perusal of his experiments on absorption, recorded in the text, will not only exonerate him from any charge of haste or negligenee, but must impress the unprejudiced reader with the conviction that those expeperiments have rarely been equalled and never excelled, either in the ingenuity and foresight manifested in their contrivance, in the skill and precaution against error displayed during their performance, in the fairness of the conclusions deduced from them, or in the minute accuracy and candour which pervade, their narration. To prove the absorbent power of the lymphatics, however, is one thing; that the veins are thereby deprived of the power of absorbing altogether is another; and it is in reference to this latter question that the experiments of M. Flandrin, recorded by M. Majendie, become interesting to the physiologist. But we may observe, en passant, that if M. Majendie and his collaborates failed to obtain the same results as Hunter from similar experiments, other and as able experimenters in recent times have been more successful. Schroeder von der Kolk, for example, filled a loop of intestine in a living dog with a solution of the ferro-prussiate of 316 HUNTER ON THE ANIMAL CECONOMY. potass, and included the distended loop between two ligatures. He then placed the loop and its contents in a solution of sulphate of iron. The blue compound, which could be formed by no other means except by the union of the two chemical fluids, was manifested in the lacteals alone, and not in the veins. (Mailer's Physiologie, p. 229.) Viridet and Mallei also found that the chyle derived from yolk of egg was yellow, while that from food mixed with madder was red. It is allowed indeed by all physiologists, and even by M. Majendie, that the lacteals absorb the chyle. But various experiments seem to show that other fluids, and especially those of a poisonous nature, are taken up from the intestines by the veins. Such was the general result of the numerous experiments of Tiedemann and Gmelin.*" Those related by Majendie are not, however, free from objection. He opened the abdomen of a dog; a loop of intestine was included between two ligatures and separated from the rest of the canal, all other connection between the intestine and the rest of the body was destroyed except a single mesenteric artery and vein. Two ounces of the decoction of nux vomica were then injected into the detached portion of gut. In six minutes the effects ofthe poison manifested themselves with the ordinary intensity. Great precaution was taken to obviate the doubt which any lacteals remaining attached to the coats ofthe vessel might have occasioned; but as this objection might still be urged, the following more conclusive experiment was performed : a limb of a dog was amputated with the exception of a single artery and vein, which alone kept up the communication between the limb and the trunk ; upas poison was then inserted into the foot (enfonces dans lapatte). Its effects became evident in less than four minutes ; in less than ten the animal was dead. To avoid the objection of invisible lymphatics in the tissue of the vessels, a segment of both artery and vein was removed, after having substituted a portion of quill, so that there remained no other communication between the limb and the animal excepting by the blood which circulated from one to the other. The poison introduced into the foot (introduit dans lapatte) produced its effects in about four minutes. What makes it so evident, adds M. Majendie, that the crural vein was the sole medium of introduction to the poison is this; that simple compression of this vessel arrested the deadly effects of the upas, which again immediately manifested themselves on a remission ofthe pressure.* Now, although the objection of lymphatics in the coats of the vessels is obviated in this experiment, yet its conclusiveness may be questioned on this ground, that the poison is applied to a wound where it can enter the circulating fluids by open and divided veins ; but this is by no means the condition which is understood in the theory of venous absorption, which relates only to an action attributed to the veins in their natural state, and through the medium of their organic pores. If this objection be invalidated by the experiment in which the decoction of nux vomica was applied to an entire mucous surface, as when injected into the intestine, yet this may be accounted for by the paralyzing effects of the narcotic upon the animal tissues with which it comes in contact: it may be objected that their vitality is destroyed, that inorganic imbibition then takes place, and that

* [Versuche Uber die Wege auf welchem Substanzen aus dem Magen und Darm Ivanal ins Blut gelangen.] f [Loc. cit., p. 255, 256.] OF ABSORPTION BY VEINS. 317 the poison thus passes into the cavity of the vessels, and is carried along the returning currents to the heart. But objections from the permeability of the tissue of a paralyzed vein are endeavoured to be overcome by the assertion that all absorption is the effect of non-vital imbibition, that it is a property which the living animal tissues possess in common with inorganic substances. Thus M. Fodera having repeated the experiment of M. Majendie and Segalas, in which the solution of nux vomica was injected into the intestine, afterwards incloses the same poisonous solution in a dead portion of intestine, inserts this into a loop of the intestines of a living animal, and from the effect produced by the transudation of the poison through the parietes of the dead intestine, and through the paralyzed surface of that ofthe animal experimented upon, draws a sweeping conclusion as to the nature of absorption in general. M. Majendie also rejects the theory of the vital actions of the absorbents, and strongly condemns the supposition of a selecting power in absorbent pores as gratuitous and unphilosophical. He threw into the thorax of a dog a solution of nux vomica, and he found that in proportion as the obstacles to a free circulation were increased, by distending the blood-vessels with warm water, the effects of the poison on the system were retarded. This experiment is ofthe same species as that by M. Segalas, who limited the field of observation by confining the poison within a loop of intestine, and interrupted the venous current altogether by a ligature; it is consequently less conclusive, though liable to the same objections. When M. Majendie removed the obstacles which he had imposed on the circular lion by opening a vein and relieving the distended vessels, the imbibed solution of nux vomica rapidly produced its effects. Thus the ordinary laws ofthe living tissue being suspended by the application of a narcotic; or other poison to them, and mechanical imbibition being thereby permitted,—or when similar poisons are directly applied to divided vessels; —it may be concluded, from the experiments abovexiuoted, that whatever anests the return of the empoisoned blood to the heart, whether atmospheric pressure, produced by the action of an exhausted cupping-glass, or by the direct pressure or ligature of the vein, or a general impediment to the circulation by a plethoric or artificial distension of vessels, will proportionately retard the deadly operations of the poison. M. Majendie has also shown that the rapidity of its action is increased by artificially diminishing the quantity of circulating fluids, and this observation is of great value in a practical point of view; but much is still wanting to sustain his conclusion that the ordinary and natural absorbent processes are arrested by a plethoric or distended state ofthe vessels, and vice versa. The experiments by which M. Majendie endeavours to support the theory of non-vital imbibition or capillary attraction as the immediate cause of absorption are these:—A saturated solution of nux vomica applied to the denuded vein of a living animal passes through the coats of that vein into the circulation and kills. The poison take3 a longer time to soak through the coats of an artery ; but having done so produces the same deadly effect. (Loc. cit., pp. 279, 280.) The nux vomica had certainly affected the system by transuding through the coats ofthe vessels, for its bitter taste could be detected in the blood which adhered to the inside of the coat of the paralysed vessels. Dead vessels and animal membranes exhibited the same permeability as those which M. Majendie 28* 318 HUNTER ON THE ANIMAL CECONOMY. imagines to have retained their vital properties unchanged after four or ten minutes' contact with the narcotic extract. Ink injected into the serous cavities ofthe body of a living animal stains the lining membrane and contiguous parts, (p. 282.) From these experiments the author concludes, " II me parait done hors de doute que tons les vaisseaux sanguins, arteriels et veineux, morta ou vivans, gros ou petits, presentent, dans leurs parois, une propriete physique propre ii rendre parfaitement raison des principaux phenomenes de l'absorption."—Ibid. To be consistent in this application of the llieory of physical imbibition to the actions of organized bodies, we ought to conclude, from observing the serum transuded after death into the pericardium, that such was the condition in the living state of the parts ; and a physiologist could no longer infer from the different appearance of the parts in the immediate proximity ofthe gall-bladder, when examined in a living and dead animal, that the condition of the coats of that receptacle as to permeability must be influenced by the two states ; and that the living tissue resists the percolation which the dead membrane readily allows. M. Majendie is, in fact, compelled by his theory to deny such difference ; " the bile," says he, " does transude through the coats of the living gall-bladder, but the sanguineous current which exists in the small vessels which form in great measure those parietes, carries it off in proportion as it transudes." Yet the same currents in the serous membranes, which at p. 258 he admits are more abundant in vessels than the mucous, have no such effect in preventing the passage ofthe ink, &c. But it is evident that he is himself not satisfied with his explanation, for in an account of one of the Hunterian experiments, in which means were adopted to ascertain whether water injected into the intestine of a living animal would be absorbed by the vein, M. Majendie observes that the vital action of the vein might be interrupted by the ligature of its corresponding artery. Now this objection ought to have no weight if, as he supposes, the veins absorb by a property of simple inorganic imbibition with which their coats are endowed. But laying aside for a moment the consideration of experiments, in all of which the vilal operations are more or less interrupted, and the parts in question forced into unnatural conditions, let us attentively consider those phaenomena of absorption which Nature plainly puts before our eyes. The chyle is known to contain globules of a definite size and form. It is admitted by M. Majendie that this fluid is exclusively taken up by the lacteal absorbents. The escape ofthe lacteal globules from the intestine could not be accounted for on the theory of imbibition or permeability of tissue; organic pores must be supposed to exist of a size adequate to their transmission. These pores have been described by Cruikshank as they were seen by himself and Dr. Wm. Hunter in the human subject; they have been witnessed by Majendie in a dog. But, says Majendie, it is unphilosophical, a mere physiological romance, to suppose that they can act in any way different from dead animal tissues ; physical imbibition, inorganic capillary attraction is the only cause ofthe transmission of fluids through animal membranes that we are acquainted with, &c. Yet these organized pores of the lacteal absorbents permit nothing to pass them, according to his own admission, except the chyle. Still it is contended that this must be a mechanical action, because lacteal absorption has been observed to go on in a dog for two hours after ON THE GROWTH OF BONES. 319 death; but what does this prove but that the automatic or involuntary actions continue for a certain time after the sensorial power is lost,— after apparent death has ensued ? Thus the only natural absorbent process in the living body that we can reason upon from the evidence afforded by the nature of the substance absorbed, and the ascertained structure of the mechanism employed in its absorption, is totally at variance with the theory of non-vital imbibition as the cause of absorption, and can only be explained by a vital or organic endowment ofthe parts concerned, whether it be regarded as a power of selection or mutual attraction, or an action whose peculiar stimulus is the contact of chyle. The various phenomena of excretory absorption, as it may be termed, render the theory ofthe capillary attraction of the tissue, whether of veins or lymphatics, as their cause, equally unsatisfactory. A property of dead matter cannot account for the rapid absorption of fat in disease ; or of the parts of muscles, &c, which, from some accident to a joint, have become useless ; or of alveoli of shed teeth ; or of the parts which in the progress of growth become inconveniently situated, as the first deposit of osseou3 matter in long bones ; or of parts which, at the conclusion of growth, are equally inconveniently situated in regard to some tumour or collection of matter, the discharge of which is salutary to the constitution, &c. A mere physical endowment of animal tissues ought always to be acting, aud acting in but one way ; and we therefore conclude, with Hunter, that these various and partial operations ofthe lymphatics are affected by the vital actions of organic pores, in a manner analogous to that which determines in the lacteals the exclusive absorption of chyle.] 31. EXPERIMENTS AND OBSERVATIONS ON THE GROWTH OF BONES, FROM THE PAPERS OF THE LATE MR. HUNTER. [Published by Mr. (afterwards SirEverard) Home, in the Second Volume ofthe Transactions of a Society for the Improvement of Medical and Chirurgical Knowledge.] Read October 4,1798.

Mr. Hunter's Observations on the Growth of Bones have been mentioned in his lectures ever since the year 1772, the first year in which he gave lectures, and have been since adopted by the principal teachers of anatomy in London; it was therefore natural for me to suppose that they were generally known. In this, however, I find I have been mistaken, since the present Professor of Anatomy in Edinburgh, in a late publication, declares himself an advocate for the doctrine of Du Hamel; and from what he advances, it appears that he was not at all acquainted with Mr. Hunter's experiments upon this subject. Under these circumstances I lay before the Society Mr. Hunter's experiments and observations, that they may be made known to the public* * [This record contains little more than a brief notice of the general results of Mr. Hunter's Observations and Experiments on the Growth of Bone.] 320 HUNTER ON THE ANIMAL CECONOMY. It was some time anterior to the year 1772 that Mr. Hunter began to investigate this subject, and an account of the experiments and observations was given to me to copy in that year, as a part of his future lectures. Du Hamel had published a very ingenious theory upon the growth of bones, which he endeavoured to support by experiments tending to prove that bones grow by the extension of their parts. With this doctrine Mr. Hunter was not satisfied, and instituted experiments to determine the truth of Du Hamel's opinion. Mr. Hunter began his experiments by feeding animals with madder, which has a property of tinging with a red colour that part only of the bone which is added while the animal is confined to this particular food.* He fed two pigs with madder for a fortnight, and at the end of that period one of them was killed ; the bones, upon examination externally, had a red appearance; when sections were made of them, the exterior part was found to be principally coloured, and the interior was much less tinned.

* [This effect of madder upon bone (first described in England by Belchier, Phil, Tr., vol. xxxix., 1736, p. 287), depends on the following chemical properties. The colouring principle ofthe Rubia Tinclorum has a strong affinity to phosphate of lime, which earth, if artificially precipitated from a solution of madder, carries down with it the colouring matter in a state of combination, which water does not disturb. The colouring principle of madder is hardly soluble in water, but is readily and abundantly soluble in albuminous fluids, and, consequently, when taken into the system as food, it is carried along, dissolved in the serum of the circulating blood, and is deposited, combined with the phosphate of lime, wherever that salt is separated from the blood to contribute to the increase or reparation of bone. There are still, however, some points connected with this subject to be determined before the reasoning from experiments with madder on the growth of bone can have all the desirable exactness. Whether, e. g. the colouring principle of madder, after having been precipitated from the blood in combination with the phosphate of lime, remains in the bone until the particles of the earth are themselves removed,—or whether the colouring matter may again be redissolved in the serum of the blood circulating through the substance ofthe bone,—are questions not yet definitively settled ; but there is much reason for believing that the colouring matter may be removed without the earth with which it had been combined. Accordingly, although an inference may be safely drawn with respect to the part of a growing bone which receives the accessions of osseous substance, by observing the part which is coloured with madder, yet we cannot so certainly conclude that a superficial colourless layer, in an animal killed after remission of the madder, is a new deposit, since it may be the old, from which the madder ha3 been removed, after having been redissolved in the serum. That the madder " tinges with a red colour that part only ofthe bone which is added," as is stated in the text, is an assertion, not only unsupported by any physiological reasoning, but directly in contradiction to Hunter's own statement, "that any part of a bone which is already formed is capable of being dyed with madder, though not so fast as the part that is forming." I may observe, incidentally, that the phaenomena under consideration throw light upon the chemical condition under which phosphate of lime is contained in the living body. Since the colouring principle of madder has no affinity for lime or calcium alone, it is clear that the phosphate of lime is not contained in the blood or the bones as phosphorus, oxygen, and calcium, but that it exists as a binary compound, and is mixed as phosphate of lime with the cartilage or animal basis of the bones.] ° ON THE GROWTH OF BONES. 321 The other pig was allowed to live a fortnight longer, but had now no madder in its food ; it was then killed, and the exterior part of the bones was found ofthe natural colour, but the interior was red. He made many other experiments ofthe same kind upon the increase ofthe thickness of the neck and head of the thigh bone. From thence it appeared that the addition of new matter was made to the tipper surface, and a proportional quantity of the old removed from the lower, so as to keep the neck of the same form, and relatively in its place.* To ascertain that the cylindrical bones are not elongated, by new matter being interposed in the interstices ofthe old, he made the following experiment: ha bored two holes in the tibia of a pig, one near the upper end, and the other near the lower; the space between the holes was exactly two inches : a small leaden shot was inserted into each hole. When the bone had been increased in its length by the growth of the animal, the pig was killed, and the space within the two shot was also exactly two inches. This experiment was repeated several times on different pigs, but the space between the two shot was never increased during the growth of the bone.f

* [Amongst the original drawings of the bones coloured by madder in the Hunterian experiments, besides those of the thigh-bone referred to in the text, there are three which illustrate the mode and direction of increase of the lower jaw, showing that the new bone is deposited in greatest proportion on the upper and posterior part ofthe ascending ramus, by which the rest of the jaw is pushed forwards, while the bone is absorbed from the anterior part ofthe ramus, and thus the sockets of the posterior grinders are gradually brought into line, with a free space above for the teeth to come forth. This mode of growth, with absorption at the symphisis of the jaw, continues throughout life in the elephant, in which new grinders are thus brought forwards into use in uninterrupted succession. _ The preparations of bones coloured with madder in the Hunterian Collection are as follows. Nos. 190 to 201 inclusive, Physiological Series ; Nos. 742 to 751, Osteological Series.] f [Meckel has rightly observed (supposing the above to be a correct statement of Hunter's experiments on this point), that they are invalidated by the careful and numerous experiments of Duhamel, which prove that the middle portion of the long bones does increase in length, though in a less degree than the extremities. It is not easy to understand how the unqualified assertion came to be published, since the preparation and record of an experiment confirmatory of those made by Duhamel are still preserved in the Hunterian Museum. The preparation (No. 188, Physiological Series), is the left tarso-metatarsal bone of a common fowl, exhibiting two perforations at equal distances, two thirds of a inch from the extremities of the bone. The original record of the experiment is preserved with the specimen.

i | 1 I " The two extreme lines are the present length of the bone from the head ofthe joint of the inner toe. The two inner lines are the length when cauterized. The outer dots are the present distance or the holes cauterized. The two inner dots are the distance of these holes when cauterized ; so that the bone between the two holes has grown about two-eighths of an inch, while the other parts have grown half an inch."—Physiological Catalogue, vol. i., p. 40. In another experiment, in which shots were inserted into the holes, the result was spoiled by the shots passing into the medullary cavity of the bone, while 322 HUNTER ON THE ANIMAL CECONOMY. Besides these experiments on the growth of bones, he made others, to determine the process of their exfoliation. He cauterized portions of bone in the same way in several different animals, so as to be able to examine the bones in the different stages of this process, and found that the earthy part of the living bone in contact with the dead portion was first absorbed ; afterwards the animal mucilage itself, so as to form a groove between the two, which became deeper and deeper, till the dead bone was entirely detached, the dead portion itself having undergone no change.* From these experiments he ascertained the changes which take place in bones during their growth, and the readiness with which the materials of bone are absorbed ; and from these facts, laid it down as an established principle, that the absorbents are the agents by means of which the bones, during their growth, are modelled as it were, and kept of the same shape. Bones, according to Mr. Hunter's doctrine, grow by two processes going on at the same time, and assisting each other; the arteries bring the supplies to the bone for its increase ; the absorbents at the same time are employed in removing portions of the old bone, so as to give to the new proper form. By these means the bone becomes larger, without having any material change produced in its external shape.f

the perforations became obliterated, as in Duhamel's experiment with the ring of wire, by the deposition of new bone from the periosteum. The shots being liberated from the osseous texture could no longer serve to indicate its growth. The subject of the experiment, the tarso-metatarsal bone of a fowl, is No. 188, Physiological Series. It is remarkable that there is not a single preparation ofthe long bone of a pig, exhibiting the experiments with shot alluded to in the text. The notes of the experiments on the bones of fowls above mentioned are in the hand-writing of Mr. Wm. Bell, Mr. Hunter's talented artist and assistant, and must therefore have been written in or before the year 1789, when Mr. Bell left England for the East Indies.] * [See Preparations Nos. 197 to 201 inclusive, Pathological Series.] t [The difference between the Huntprian theory ofthe growth of bone and that of Duhamel will be readily appreciated by attending to the explanation given by Duhamel of the phaenomena which he observed during his investigations on this subject. Let us, for example, select from the number of his ingenious and instructive experiments, that in which he placed a ring of silver wire round the middle of the shaft of the thigh-bone of a young pigeon; and found at a subsequent period the ring in the medullary cavity of the bone, instead of embracing the exterior of the shaft, where he had placed it. It need scarcely be observed that the Hunterian physiologist would explain these facts by stating that the arteries ofthe periosteum had deposited new bone on the external surface of the ring, while the absorbents had removed the old bone in contact with the internal surface of the ring, by which its relations to the osseous parietes of the femur became reversed. But this physiolooical view of the pha;nomena, arising out of a knowledge of the powers and actions of great and important vascular systems in the frame, was wholly unsuspected by and unknown to the predecessors of Hunter. Duhamel explains the facts on mechanical principles ; assuming that the bony layers ofthe shaft of the thigh-bone were expanded by the interposition of additional osseous matter, and that the layers were cut through in this process of expansion by the unyielding wire which he had placed around them. All his explanations bear the same mechanical character, in which processes of growth are assumed which are negatived by observation; and they are frequently vitiated OF THE WOLF, JACKAL, AND DOG. 323 32. OBSERVATIONS TENDING TO SHOW THAT THE WOLF, JACKAL, AND DOG, ARE ALL OF THE SAME SPECIES.

The true distinction between different species of animals must ultimately, as appears to me, be gathered from their incapacity of propagating with each other an offspring capable again of continuing itself by subsequent propagations : thus the horse and ass beget a mule capable of copulation, but incapable of begetting or producing offspring. If it be true that the mule has been known to breed, which must be allowed to be an extraordinary fact, it will by no means be sufficient to determine the horse and ass to be of the same species; indeed, from the copulation of mules being very frequent, and the circumstance of their breeding very rare, I should rather attribute it to a degree of monstrosity in the organs of the mule which conceived, as not being a mixture of two different species, but merely those of either the mare or female ass. This is not so far-fetched an idea, when we consider that some true species produce monsters, which are a mixture of both sexes, and that many animals of distinct sex are incapable of breeding at all. If then we find Nature in its most perfect state deviating from general principles, why may it not happen likewise in the production of mules; so that sometimes a mule shall breed from the circumstance of its being a monster respecting mules? The time of uterine gestation being the same in all the varieties of every species of animals, it becomes a necessary circumstance towards determining a species. The affinity between the fox, wolf, jackal, and several varieties ofthe dog, in their external form and several of their properties, is so striking, that they appear to be only varieties ofthe same species. The fox would seem to be further removed from the dog than either the jackal or wolf, at least in disposition, being naturally a solitary animal, and neither so sociable respecting its own species or man; from which I should infer that it is only allied to the dog by being ofthe same genus. It is confidently asserted by many that the fox breeds with the dog; but this has not been accurately ascertained ; if it had, the inquiry would probably have been carried further; and once breeding, according to what we have said, does not constitute a. species ; this, however, is a part I mean to investigate. I do not know if, in a wild state, there ever is in the same country a

by overstrained analogies, as where, in explaining the process of union in a fractured bone, he compares the periosteum to the bark of trees. But the numerous experiments of Duhamel,3 which are characterized by much precision and ingenuity, well merit the attention of the student of Physiology.]

a [Sur le development et la crue des os. Memoires de l'Acad. des Sciences. Paris, 1742, p. 497 ; and 1743, p. 187.] 324 HUNTER ON THE ANIMAL CECONOMY. variety in any species of animal, but am inclined to think there never is; if so, as both wolves and foxes inhabited this country, they cannot then be of the same species. Wolves, as also jackals, are found in herds; and the jackal is so little afraid of the human species, that, like a dog, it comes into houses in search of food, more like a variety of the dog, the consequence of cultivation rather than of chance. It would appear to be much the most familiar of the two; for we shall find that in its readiness to copulate with the dog, and its familiarity with the dog afterwards, it is somewhat different from the wolf; however, this may depend on accident. The wolf being an animal well known in Europe, the part of the world where natural history is particularly cultivated, some pains have been taken to ascertain whether or not it was of the same species with the dog; but I believe it has been hitherto considered as only belonging to the same genus. Accident often does as much for natural history as premeditated plans, especially when Nature is left to herself. The first instance of the dog and wolf breeding in this country seems to have been about the year 1766. A Pomeranian bitch of Mr. Brookes's, in the New Road, was lined only once by a wolf, and brought forth a litter of nine healthy puppies. The veracity of Mr. Brookes is not to be doubted, respecting the bitch having been lined by a wolf; yet as it was possible she might have been lined by some common dog without his knowledge, the fact was not, in that, clearly made out; but it has since been ascertained that the dog and wolf will breed. One of the above-mentioned litter was presented to me by Mr. Brooks, who likewise informed me that others had been purchased by different noblemen and gentlemen, and named Lord Clanbrassil as having bought a bitch puppy. I reserved mine for the purpose of experiment; and from observation it appeared that its actions were not truly those of a dog, having more quickness of attention to what passed, being more easily startled, as if particularly apprehensive of danger, quicker in transitions from one action to another, being not so ready to the call, and less docile. From these peculiarities it lost its life, having been stoned to death in the streets for a mad dog. Hearing that Lord Clanbrassil's bitch had bred, Sir Joseph Banks was so obliging as, at my request, to write to his Lordship, who sent the following account: « Sir, " About seventeen or eighteen years ago, the late Lord Monthermer and I happened to see a dog-wolf at Mr. Brookes's, who deals in animals, and lives in New Road. The animal was remarkably tame, and it struck us, for that reason, that a breed might be procured between him and a bitch. " We promised Mr. Brookes a good price for puppies if he succeeded. In about a year a bitch produced nine, and Lord xAIonthermer bought one; and I had another, which was a bitch. Lord Monthermer'sdied of fits in about two years : mine lived longer, and OF THE WOLF, JACKAL, AND DOG. 325 had puppies only once. One I gave to Lord Pembroke, but what became of it I do not remember. It was granddaughter of the wolf by the dam, and got by a large pointer of mine. " It might be considered that Mr. Brookes's word was not sufficient proof that the puppies were really got by the wolf, but the appearance ofthe animals, so totally diflerent from all others ofthe canine species, did not leave a doubt upon our minds; and I remember Hans Stanley, who had adopted Buffbn's opinion, was thoroughly convinced upon seeing mine. The animals had the shape of the wolf refined ; the fur long, but almost as fine as that ofthe black fox. "I am afraid I have trespassed too much upon your time, and will only beg you will be assured nothing can give me more pleasure than any opportunity of assuring you how truly " I am, sir, &c. " Jan. 7,1787. " Clanbrassil." Upon the supposition that Mr. Brookes's bitch was not lined by a dog, but by the wolf, which I think we have no reason to doubt, the species of the wolf is ascertained; but choosing to trace this matter still further, and hearing that Lord Pembroke's bitch had likewise bred, I was desirous to know the truth of it; and as his lordship was in France I took the liberty of writing to Lord Herbert, and received the following answer : " Sir, Wilton House, Dec. 20, 1786. "The half-bred wolf-bitch you allude to was given, as I always understood, to Lord Pembroke by Lord Clanbrassil. She might, perhaps, have been bought at Brookes's by him. She had four litters, one of ten puppies, by a dog between a mastiff and a bull-dog. One of these was given to Dr. Eyre, at Wells in Somersetshire, and one to Mr. Buckett at Stockbridge. The second litter was of nine puppies, some of which were sent to Ireland, but to whom 1 know not. This litter was by a different dog, but of the same breed as the first. The Ihird litter was of eight puppies, by a large mastiff. Two of these were, 1 believe, sent to the present DukeofQueensberry. The fourth litter consisted of seven puppies, two of which were sent to M. Cerjat, a gentleman who now resides at Lausanne in Switzerland, and is famous for breaking dogs remarkably well. These two puppies were, however, naturally so wild and unruly, that he found it impossible to break them. She died four years ago, and the following inscription was put over the place where she is buried in this garden, by Lord Pembroke's orders: Here lies Lupa, whose grandmother was a wolf, whose father and grandfather were dogs, and whose mother was half wolf and half dog. She died on the 16th of October, 1782, aged 12 years. 29" 326 HUNTER ON THE ANIMAL CECONOMY. " I am sorry it is not in my power to give you any better account; but if you think proper to write to Lord Pembroke, who is at Paris, I am convinced he will be very happy to give you any further information. " I am, &c. " Herbert." Buffon, whose remarks in natural history are well known, made experiments to ascertain how far the wolf and dog were of the same species, but without success. He says, " A she-wolf, which I kept three years, although shut up very young, and along with a greyhound of the same age, in a spacious yard, could not be brought to agree with it, nor endure it, even when she was in heat. She was the weakest, yet the most mischievous, provoking, attacking, and biting the dog, which at first only defended itself, but at last killed her." And in another part of his work he makes the following observation : " The dog, the wolf, the fox, and the jackall, form a genus, of which the different species are really so nearly allied to each other, and of which the individuals resemble each other so much, particularly by the internal structure and parts of generation, that it is difficult to conceive why they do not breed together."* This part of natural history lay dormant, till Mr. Gough, who sells birds and has a collection of animals on Holborn-hill, repeated the experiment on a wolf-bitch, which was very tame, and had all the actions of a dog under confinement. A dog is the most proper subject for comparison, as we have opportunities of being acquainted with its disposition and mode of expressing its sensations, which

* In the Supplement to his Works he gives the following account which had been sent to him. " A very young she-wolf, brought up at the Marquis of Spontin's, at Namur, had a dog, of nearly the same age, kept with it as a companion. For two years they were at liberty, coming and going about the apartments, the kitchen, the stables, &c, lying under the table, and upon the feet of those who sat round it. They lived in the greatest familiarity. "The dog was a strong greyhound. The wolf was fed on milk for six months; after that, raw meat was given her, which she preferred to that which was dressed. When she ate no one durst approach her, but at olher times people might do as they pleased, provided they did not use her ill. At first 6he made much of all the dogs which were brought to her, but afterwards she gave the preference to her old companion, and from that time she became very fierce if any strange dog approached her. She was lined for the first time on the 25th of March ; this was frequently repeated while her heat continued, which was sixteen days; and she littered the 6th of June, at eight o'clock in the morning ; the period of gestation was therefore seventy-three days at the most.a She brought forth four young ones of a blackish colour, some of whose feet, and a part of the breast, were white ; in this respect taking after the dog, which was black and white. From the time she littered she became surly, and set up her back at those who came near her; did not know her masters, and would even have killed the dog if it had been in her power." a This is a longer period than in the hitch by at least ten days, but as the account was made from the first lime of her being lined, and she was in heat for a fortnight, and lined in that time, it is very probable, if the time was known when she conceived, that it would prove to be the same period as in the dog. OF THE WOLF, JACKAL, AND DOG. 327 are most distinguishable in the motion of the ears and tail; such as pricking up the ears when anxious, wishing, or in expectation; depressing them when supplicant or in fear; raising the tail in anger or love, depressing it in fear, and moving it laterally in friendship; and likewise in raising the hair on the back from many affections of the mind. This animal became in heat in the month of December 1785; and Mr. Gough having an idea of obtaining a breed from wild animals, as monkies, leopards, &c, he was desirous to have the wolf lined by some dog; but she would not allow any dog to come near her, probably from being always chained, and not accustomed to be with dogs. She was held, however, while a greyhound dog lined her, and they fastened together exactly like the dog and bitch. While in conjunction she remained pretty quiet, but when at liberty endeavoured to fly at the dog ; yet in this way was twice lined. She conceived, and brought forth four young ones; and though the time she went with young was not exactly known, it was believed to be the same as in the bitch. Two of these puppies were like the dog in colour, who had large black spots on a white ground ; another was of a black colour; the fourth of a kind of dun, and would probably have been like the mother.* She took great care of them, yet did not seem very anxious when one was taken from her by the keeper; nor did she seem afraid when strangers came into the room. Unfortunately these experiments were carried no further: one of the puppies being sold to a gentleman, who carried it to the East Indies; and the other three, one of which I was to have had, were killed by a leopard. The same wolf was in heat in December 1786, and was lined several times by a dog. She pupped on the 24th of February 1787, and had six puppies, one of which, a bitch, I had, and kept it till it was in heat; but missed the opportunity of having her lined. That loss, however, was made up by a wolf-bitch belonging to James Symmons, Esq., of Grosvenor-house, Milbank: the history of which is as follows: This female wolf had been in his possession some time, had been lined by a dog, and brought forth several puppies, which I saw in company with Sir Joseph Banks, soon after Mr. Gough's wolf, the subject of my former paper, had produced her litter; so that these puppies were nearly of the same age with mine. Mr. Symmons reared them all; but one only was a female, which more resembled the mother or wolf kind than any ofthe others. I communicated

* [Here it may be observed, that, from the known disposition of varieties to revert to the original, it might have been expected, on the supposition that the wolf is the original of the dog, that the produce of the wolf and dog ought rather to have resembled the supposed original than the variety. In a litter lately obtained, in the Royal Menagerie at Berlin, from a white pointer and a she-wolf, two ofthe cubs resembled the common wolf-dog, but the third was like a pointer with hanging ears.a]

• [Lyell, Principles of Geology, vol. ii., p. 438, who cites Wiegmann for this fact.] 328 HUNTER ON THE ANIMAL CECONOMY. to Mr. Symmons my wish that we should endeavour to prove the fact of the wolf and dog being of the same species, by having either his female or mine lined by a dog. This he very readily acceded to; and his bitch received the dog on the 16th, 17th, and 18th of December, 1788; and the 18th of February following she brought forth eight puppies, all of which she reared. If we reckon from the 16lh of December, she went sixty-four days; but if we reckon from the 17th, the mean time, then it is sixty-three days, the usual time for a bitch to go with pup. These puppies are the second remove from the wolf and dog, and similar to that given by my Lord Clanbrassil to the Earl of Pembroke, which likewise bred again. (See Philosophical Transactions, voi. lxxvii., p. 255.) It would have equally proved the same fact if she had been lined either by a wolf, a dog, or one of the males of her own litter.* It is remarkable that there seems to be only one time in the year in which impregnation is natural to the wolf, which is the month of December: for Mr. Gough's wolf has always been in heat in that month ; so was that of Mr. Simmons. The time of heat in his of the half-breed (which is nearly of the same age with mine) corresponded likewise with that of the mother, and of those bred from Mr. Gough's wolf.

This animal being so nearly allied to the dog, and only found wild like the wolf, I became desirous of ascertaining of what particular species it was; and while pursuing the subject, I was informed that Captain Mears, of the Royal Bishop, East Indiaman, had brought home a bitch-jackal with young, which brought forth soon after his arrival; and that he had given the bitch-jackal and one puppy to Mr. Bailey, bird-merchant, in Piccadilly. I went to see them, and purchased the puppy, the subject of the following experiment, which wre found to have dispositions very similar to those of the half-bred wolf before-mentioned, which I had from Mr. Brookes.

* [This assertion, that the fertility of a hybrid with an individual of a pure breed proves the fact of identity of two supposed distinct species equally with the production of offspring from the connection of hybrid with hybrid, cannot be admitted. To prove the identity of two supposed distinct species, granting that the fertility of the hybrids from the two to be the proof required, it should be shown that such hybrids are fertile inter se, and capable of propagating indefinitely an intermediate variety. Now this is precisely the fact which*is wanting in the evidence adduced in the text. All that Hunter proves is that two species very nearly allied to each other will produce a hybrid offspring, and that the hybrid is again productive with an individual of the pure breed ;°but this only illustrates a general law by which the reversion ofthe hybrid to the pure breed is provided for; while, on the other hand, the intermixture of the distinct species is guarded against by the aversion of the individuals composing them to sexual union : an aversion which we see in the case of Mr. Gough's female wolf to have been only overcome by force.] OF THE WOLF, JACKAL, AND DOG. 329

To have a true history of this animal, I took the liberty of writing to Mr. Mears, who politely called upon me, and, at my request, sent me the particulars in a letter, of which the following is a copy :

« Sir, " I had the honour of yours ofthe 15th instant; and with regard to the female-jackal, I can assure you that she took a small spaniel dog of mine on board my ship, the Royal Bishop. I had her, when a cub, at Bombay ; and a very short time before I arrived in England she got to heat, and enticed this small dog into the longboat, where I saw them repeatedly fast together. I brought her to my house in the country, where she pupped six puppies, one of which you have seen. Mr. Plaw, at No. 90, Tottenham-court Road, has a dog-puppy, which will be at your service at any time you chuse to send for him, to make further experiments: I called on Mr. Plaw, and got his promise to let you have the dog. " I have the honour to be, sir, &c. "Wm. Mears. "No. 107, Hatton-street, 16th Jan. 1786. "P.S. I had the bitch on board fourteen months."

Having taken this puppy into the country, and chained it up near a mastiff-dog, they became very familiar, and seemingly fond of each other. When the bitch became first in heat I could not get a proper dog: but about the latter end of September, she being again " in the same state, several dogs were procured and left with her.— They appeared indifferent about her, probably from being in a strange place; nor did she seem inclined to be familiar with ihem. One of them was a large dog, which might not perhaps be able to line her; but she was twice tied by a terrier on the 3d of October. In a few weeks she was evidently bigger; and on the 30th of November, in all fifty-nine days, brought forth five puppies. A few days before this period she dug a hole in the ground, by the side of her kennel, in which she littered; and it was some time before she would allow the puppies to stay in the kennel when put there. Some of these began to open their eyelids in about eight, others of them in nine days. Here then being an absolute proof of the jackal being a dog, and the wolf being equally made out to be of the same species, it now therefore becomes a question whether the wolf is from the jackal, or the jackal from the wolf (supposing them but one origin) ? From the supposition that varieties become more tame in their nature than the originals, we should be led to believe the wolf to be the original, and that the jackal was a step towards civilization in that species of animal, and that therefore the jackal should be considered as a variety of the wolf. There are wolves of various kinds, each country having a kind peculiar to itself; but the jackals that I have seen have been more uniform in resemblance to each other, probably because only to be found in one country, the East Indies. I am informed, however, that they vary in size. Whether the wolves 29* 330 HUNTER ON THE ANIMAL Q3CONOMY. of different countries are of one species, or some of them only of the same genus, I do not know; but I should rather suppose them to be all of one species. An argument with me in favour of this supposition is, that if there were wolves of distinct species, we should have had by this time a great variety of every species of wolf, with the various dispositions arising from variation in other respects; and those varieties would now have been turned to very useful purposes, as in the case ofthe dog: for all the wolves we are yet acquainted with should have naturally the principle of cultivation in them (as much probably as any animal), as much at least as those wolves we now know by the name of dogs. The not having a civilized species with all the characteristics of the wolf is, indeed, with me a proof that they are all ofthe same species with the dog. If they are all ofthe same species with the dog, then the first variety that took place would be still in the character of a wolf, differing only in colour or some trivial circumstance, which could only arise from a difference in climate. The wolf is naturally, I believe, the inhabitant of cold climates, and little variety could take place while it remained in such a situation; but if the jackal was originally a wolf, which had strayed by accident more to the southward, a greater variation from the genuine character might be produced, the difference of climate, and perhaps of food, becoming causes of variety. By continuing to inhabit a warm climate, this circumstance would in time lose part of its influence on the animal, and the jackal would admit of little more variety. This, however, is a point not now to be determined, it being difficult (perhaps impossible) to say where the wolf became jackal, or (what we call) dog; and, as dogs differ much from one another, what particular dog may be considered as the first remove; or whether the jackal is the intermediate link connecting the wolf and dog. In any case we may reckon three great varieties in this species, wolf, jackal, and dog; which again branch into their respective less obvious varieties. If the dog proves to be the wolf tamed, the jackal may probably be the dog returned to ils"wild state; which leads to anolher curious question: Whether, as animals vary from climate, cultivation, or what may be called differences in mode of living, they would return to their genuine character if allowed to go wild again in the original country? To ascertain the original animal of a species, all the varieties of that species should be examined, to see how far ihey have the character of the genus, and what resemblance they bear to the other species of the genus; for it is natural to suppose that the original animal, or that which is nearest to it, will have more of the true character of the genus, and a stronger resemblance to the species nearest allied to it, than any of the other varieties of its own species. If we apply this to the dog, and consider the fox as a distinct species, which there is great reason to believe it is, that variety which has the greatest resemblance to the fox is to be looked upon as the original of all the others: which will prove to be the wolf. l OF THE WOLF, JACKAL, AND DOG. J 331

Another mode of considering this subject, which is, however, secondary to the above, is by supposing that all animals were at first wild ; and therefore that those animals which remain wild are the original stock ; and that when we find animals far removed from their originals in appearance the variation takes place in consequence of cullivation, yet so that we can still trace the gradation. What gives some force to this idea is, that where the dogs have been least cultivated, there they still retain most of their original character, or similarity to the wolf or the jackal, both in shape and disposition. The shepherd's dog, all over the world, has strongly the character of the wolf or jackal; so that but little difference is to be observed, except in size and hair. That of size may perhaps take place under a variety of circumstances ; but difference in hair is in general, although not always, influenced by climate. Thus the wolf has longer and softer hair than the jackal, because a more northern animal; while the jackal of the East, and the shepherd's dog in Portugal and Spain, have shorter and stronger hair than those of Germany or Kamtschatka, from inhabiting warmer climates. But when we consider their general shape, the character of countenance, the quick manner, with the pricked and erect ears, we must suppose them varieties of the same species. The smelling at the tail bas been mentioned as characteristic ofthe dog; but I believe it is common to most animals, and only marks the male, for it is the most certain way the male has of knowing the female, and by another scent discovering whether the female is disposed to receive the male, which is perhaps the final intention. The Esquimaux dog, and that found among the Indians as far south as the Cherokees, the shepherd's dog in Germany, called Pomeranian, the shepherd's dog in Portugal and Spain, have all a strong similarity to the wolf and jackal. Buffon, on the origin of dogs, seems to have had nearly the same idea : for he says the shepherd's dog is the original stock from which the different kinds of dog have sprung. As the wojf turns out to be a dog, it seems astonishing that there was no account of dogs being found in America. But this I consider as a defect in the first history of that country, as there are wolves; and I must think, in spite of all that has been said to the contrary, that the Esquimaux and Indian dog is only a variety from a wolf of that country which had been tamed. Mr. Cameron, of Titchfield-street, who was many years among the Cherokees, and considerably to the westward of that country, observes that the dog found there much resembles the wolf, and that the natives consider it to be a species of tame wolf; but as we come more among the Europeans who have settled there, the dogs are more of a mixed breed. Why the Cherokees should have had only this kind of dog transported among them, while every other part of America has the varieties of Europe, is not easily solved. The voice of animals is commonly characteristic of the species; but I should suppose it to be only characteristic ofthe original spe- 332 HUNTER ON THE ANIMAL CECONOMY.

cies, and not always ofthe variety, and the supposition holds good in the dog species. Dogs may be said to have a natural voice and a variation, arising either from a variety having taken place in the species, or a kind of imitation. It would appear that the voice of the wolf and the jackal is very similar, being the natural voice, and is principally conveyed through the nose, and exactly resembling that noise in dogs which is a mark of longing or melancholy and also of fondness, but having no resemblance to the bark of the dog, which they do not perform. However, in catching a jackal, when the animal found it could not escape, it yelped like the dog, which is a kind of barking, and which is probably the natural sound. Barking is peculiar to certain varieties of the dog kind, and even of those that bark some do it less than others: the dogs in the South Sea Islands do not bark, our greyhound barks but little, while the mastiff and many of the smaller tribe, as spaniels, are particularly noisy in this way. There is reason to believe that the frequency of this noise may arise from imitation : for the dogs in the South Sea Islands learn to bark, the half-breed jackal barked, and so did the half-breed wolf, although but little; and others, as the hound, have a peculiar howl, by huntsmen called the tongue, which noise, and the barking also, are both made by opening the mouth. A variety in the voice, or some parts of the voice, in varieties of the same species, is not peculiar to the dog. It is a curious circumstance that variety not only takes place in colour and form, from the change of habits in the parents, but that the dispositions are also changed; and that the dispositions are most commonly changed in such a way as appears best adapted to the form of the animal. The change in the habits of the parent animal arise principally from its connection with the human kind, which has now succeeded in training dogs so as to fit them, both in body and mind, for almost every purpose of human ceconomy, as if man himself had formed them expressly with such intention, while at the same time he can only be considered as an occasional cause, for we may observe that all the males of the wolf kind arc nearly the same, and so are likewise those of the jackal, having little or no variety in their dispositions. Those of the half-breed, and even those that are three removes, although tame, yet have not the docility of dogs, nor are they so immediately at the command ofthe human will; neither are they perfectly satisfied with an artificial life, having when left to themselves a propensity to fall back into their original instinctive principles.*

* [The range of deviation from the original type appears to be greater in the dog than in any other known species. Besides the well known and considerable differences in the quantity, colour, and texture of the hair, and in the size, form, and proportions of the body, in some individuals an additional false grinder appears; and there is a race of dogs which have a supernumerary toe on the hindfoot, with the corresponding tarsal bones ;a—a variety analogous to the Dorking (or five-toed) fowl, and to the six-fingered families ofthe human race.] 8 [Cuv. Disc. Prelim. Ossern. Fossiles, Ed. iv. torn, i., p. 205.] OF THE WOLF, JACKAL, AND DOG. 333 The following account from Mr. Jenner, of Berkeley, to whom I gave a second remove, viz., three parts dog, is very descriptive of this propensity: "The little jackal-bitch you gave me is grown a fine handsome animal; but she certainly does not possess the understanding of common dogs. She is easily lost when I take her out, and is quite inattentive to a whistle. She is more shy than a dog, and starts frequently when a quick motion is made before her. Of her inches she is uncommonly fleet, much more so than any dog I ever saw. She can turn a rabbit in the field ; she is fond of stealing away and lying about the adjacent meadows, where her favourite amusement is hunting the field-mouse, which she catches in a particular manner." As animals are known to produce young which are different from themselves in colour, form, and dispositions, arising from what may be called the unnatural mode of life, it shows this curious power of accommodation in the animal ceconomy, that although education can produce no change in the colour, form, or disposition of the animal, yet it is capable of producing a principle which becomes so natural to the animal that it shall beget young different in colour* and form, and so altered in disposition as to be more easily trained up to the offices in which they have been usually employed, and having these dispositions suitable to such change of form. It also becomes a question, whether they would not go back again to their original state, if put into the situation of the original from whence they sprang; or acquire a form resembling the original of that country where they are placed. I do not conceive that they must necessarily go back through the same changes; but I have some reason to suppose they would gradually return to a resemblance of that original.f And it would be difficult to prove whether, in many of the gradations, they are progressive or retrograde. But this is a subject that requires particular attention and investigation, and upon which, I hope, some time or other, to be able to throw more light.

* [This has recently been exemplified in the produce of a male and female Dingo, or wild dog of Australia, brought forth at the Zoological Gardens, and under circumstances which precluded the possibility of connection between the female and any other dog than the male with which she was kept confined. Two, out of the litter of five puppies brought forth, had the uniform red-brown colour ofthe parents, the rest were more or less pied, brown and white.] f [If the wolf were actually the original of the dog, it might have been expected that the Dingo of Australia, supposing it to have originated from some dog accidentally introduced into that continent, would have been found reverted to its original condition, or as a wolf. But there appears to have been no further progress towards the acquisition ofthe characters ofthe wolf, in this instance, than may be supposed, on the theory of reversion, to have taken place in the time of Cook. The existence of wild dogs which are not wolves, as the Dingo of Australia and the Dhole of India, which have either lost or have never acquired the common character of domestication, variety of colour, is itself a strong argument against the original of the domestic dog ever having been a wolf.] 334 HUNTER ON THE ANIMAL OECONOMY. 33. OBSERVATIONS ON THE STRUCTURE AND (ECO- NOMY OF WHALES. BY JOHN HUNTER, ESQ., F.R.S.*

The animals which inhabit the sea are much less known to us than those found upon land; and the ceconomy of those with which we are best acquainted is much less understood ; we are, therefore, too often obliged to reason from analogy where information fails, which must probably ever continue to be the case, from our unfitness to pursue our researches in the unfathomable waters. This unfitness does not arise from that part of our ceconomy on which life and its functions depend, for the tribe of animals which is to be the subject of this Paper has, in that respect, the same ceconomy as man, but from a difference in the mechanism by which our progressive motion is produced. The anatomy of the larger marine animals, when they are procured in a proper state, can be as well ascertained as that of any others, dead structure being readily investigated. But even such opportunities too seldom occur, because those animals are only to be found in distant seas, which no one explores in pursuit of natural history; neither can they be brought to us alive from thence, which prevents our receiving their bodies in a state fit for dissection. As they cannot live in air, we are unable to procure them alive. Some of these aquatic animals yielding substances which have become articles of traffic, and in quantity sufficient to render them valuable as objects of profit, are sought after for that purpose; but gain being the primary view, the researches of the Naturalist are only considered as secondary points, if considered at all. At the best our opportunities of examining such animals do not often occur till the parts are in such a state as to defeat the purposes of accurate inquiry, and even these occasions are so rare as to prevent our being able to supply, by a second dissection, what was deficient in a first. The parts of such animals being formed on so large a scale, is another cause which prevents any great degree of accuracy in their examination, more especially when it is considered how very inconvenient for accurate dissections are barges, open fields, and such places as are fit to receive animals or parts of such vast bulk. v As the opportunities of ascertaining the anatomical structure of large marine animals are generally accidental, I have availed myself as much as possible of all that have occurred; and, anxious to get more extensive information, engaged a surgeon, at a considerable expense, to make a voyage to Greenland, in one of the ships employed in the whale fishery, and furnished him with such necessaries as I thought might be requisite for examining and pre-

* [Originally published in the Philosophical Transactions, vol. lxxvii. 1787.] OBSERVATIONS ON THE STRUCTURE, ETC. 335

serving the more interesting parts, and with instructions for making general observations; but the only return I received for this expense was a piece of whale's skin, with some small animals sticking upon it. From the opportunities which I have had of examining different animals of this order, 1 have gained a tolerably accurate idea of the anatomical structure of some genera, and such a knowledge of the structure of particular parts of some others, as to enable me to ascertain the principles of their ceconomy. Those which I have had opportunities of examining were the following: Of the Delphinus Phoccena, or Porpoise, I have had several, both male and female. Of the Grampus I have had two; one of them, (Delphinus Orca, Linn. Tab. XLIV.) twenty-four feet long, the belly of a white colour, which terminated at once, the sides and back being black; the other about eighteen feet long, the belly white, but less so than in the former, and shaded off into the dark colour of the back. Of the Delphinus Delphis, or Bottle-nose whale (Tab. XLVI.), I had one sent to me by Mr. Jenner, surgeon, at Berkeley. It was about eleven feet long. I have also had one twenty-one feet long, resembling this last in the shape of the head, but of a different genus, having only two teeth in the lower jaw (Tab. XLVII.); the belly was white, shaded off into the dark colour of the back. This species is described by Dale in his Antiquities of Harwich. The one which I examined must have been young, for I have a skul! of the same kind nearly three times as large, which must have belonged to an animal thirty or forty feet long. Of the Balama rostrata of Fabricius I had one seventeen feet long. (Tab. XLVIII.) The Bala>na Mysticetus, or large Whalebone whale, the Physeter Macrocephalus, or Spermaceti whale, and the Monodon Monoceros, or Nar-whale, have also fallen under my inspection. Some of these I have had opportunities of examining with accuracy, while others I have only examined in part, the animals having been too long kept before I procured them to admit of more than a very superficial inspection.*

* [Cuvier, in his masterly Chapter on existing Cetaceans (Ossem. Foss.,tom. v. pt. i.), divides the Balsense or true whales, (cetaceans having the roof of the mouth furnished with baleen or whalebone), into those which have, and those which have not a dorsal fin. Of the latter he admits but one species, frequenting the northern latitudes, to be accurately defined, viz., the Balxna Mysticetus of Linnseus, and which Hunter, from the relative size of its baleen-plates terms the 'large whalebone whale.' The species of Bulxna found in the southern latitude differs, according to Cuvier, from the Bal. Mysticetus, in having all its cervical vertebrae anchylosed, while in Bal. Mysticetus the five posterior cervical vertebrae remain detached ; and in the number of ribs, which are thirteen pairs in the 336 HUNTER ON THE ANIMAL CECONOMY. From these circumstances it will be readily supposed that an accurate description of all the different species is not to be expected; but having acquired a general knowledge of the whole

Bal. Mysticetus, and fifteen in the Bal. Australis.- there are also well-marked differences in the form ofthe skull in the two species. Of the fin-backed whales or Balsenopterz, Cuvier considers the existence of the species without ventral plicae, called gibbar or finfish, as reposing on more than doubtful authority : in the original figure by Martens (VoyageduSpitzbtrg, 1671), Cuvier supposes that the plicae were accidentally omitted, rather than absent in nature, since he finds that the skull of the so called gibbar, figured by Camper, and its skeleton figured by Albers (Icones ad Anal., Comp. illustr.), are identical with those ofthe Rorquals or Balxnopterx with the skin of the throat and forepart of the abdomen disposed in longitudinal folds. Mr. Hunter had evidently never met with a specimen of the supposed gibbar, and, as he derived his observations from Nature alone, he did not contribute towards perpetuating the error of Martens, as most nomenclative naturalists and compilers had done up to his time, and continued to do until the publication of the works of Scoresby and Cuvier. The principal characters by which the Rorquals (Balxnoplerx) differ from the Balxnx,are the greater flatness of the head, the lower jaw projecting beyond the upper, the skin under the throat, chest, and anterior part of the abdomen longitudinally plicated and dilatable ; the short and hard baleen-plates, terminating in stiff and brittle bristles, a short and thick fin on the hinder region of the back. Of the Balxnoplerx which frequent the northern latitudes three species have been admitted into the Zoologists' Catalogues, Balxnnptera Boops, Bal. musculus, Bal. rostrafa. Cuvier submits these species to a criticism, severe, as usual, but just; he finds that no two of the species have ever been compared or seen by one naturalist, either together or at different periods : that the only appreciable differences he can gather from the best of their accounts resolve themselves into those of size or degrees of mutilation of the dorsal fin : and he asks, " Qui nseroit, d'apres 1'observation d'individus vus isolement a de grandes distances de temps et de lieux, et par de personnes diverses, soutenir que ces differences ne venoient pas de l'age ]" Fabricius, however, assigns three rows of low ridge9 on the upper part of the head, extending forwards from the blow-holes, as a character distinguishing his Bulxna Buops from Bulxna rostrata.- a more important distinction is afforded by the number of vert;-brae. The Bal. musculus attains, according to Scoresby, the length of seventy or eighty feet ; the Bal. Boops ofthe same author that of forty-six feet. The Bal. rostrata of Fabricius is variously described as seventeen, twenty, and twentyfive feet in length. The young Rorqual dissected by Hunter was but seventeen feet long, and he accordingly refers it to the Bui. rostrafa of Fabricius. In speaking of it he generally uses the term applied by Sibbald to the species of which this is supposed by Cuvier to be the young, viz., ' piked whale;' and sometimes from the relative size ofthe baleen plates, calls it 'small whalebone whale,' in contradistinction to the 'large whalebone whale,' or Bulxna mysticetus; not referring to the relative difference in the general bulk ofthe body, in which the ' small whalebone whale' (Bulxnoptera Boops, Cuv ) has the advantage, since il attains the length of from eighty to onu hundred feet, while the 'laTge whalebone whale' was never seen by Scoresby to exceed the length of sixty feet, nor was ever reported to him to have been longer than sixty-seven feet. The whale described by Dale, in Taylor's Antiquities of Harwich (p. 411, pi. xiv.), of which species Hunter dissected an individual, twenty-one feet in length, is generally called by him the ' great bottle-nose whale,' in coiitradintinction to the Delphinus tursio, which he calls also 'bottle-nose,' or 'small bottlenose whale/ Dale's wfule is distinguished chiefly by the presence of only two small teeth in the lower jaw, and a number of horny tooth-like projections from OBSERVATIONS ON THE STRUCTURE, ETC. 337

tribe from the different species which have come under my examination, I have beenr enabled to form a tolerable idea, even of parts which I have only had the opportunity of seeing in a very cursory way. General observation would lead us to believe that the whole of this tribe constitutes one order of animals, which naturalists have subdivided into genera and species; but a deficiency in the knowledge of their ceconomy has prevented them from making these divisions with sufficient accuracy ; and this is not surprising, since the genera and species are still in some measure undetermined, even in animals with which w7e are better acquainted. The animals of this order are in size the largest known, and probably, therefore, the fewest in number of all that live in water. Size, I believe, in those animals which feed upon others, is in an inverse proportion to the number of the smaller ; but I believe this tribe varies more in that respect than any we know, viewing it from the whalebone whale, which is seventy or eighty feet long,* to the porpoise, that is five or six: however, if they differ as much among themselves as the salmon does from the sprat, there is not that comparative difference in size that would at first appear. The whalebone whale is, I believe, the largest; the spermaceti whale the next in size (the one which I examined, although not full grown, was about sixty feet long); the grampus, which is an extensive genus, is probably from twenty to fifty feet long; under this denomination there is a number of species.

the roof of the mouth, which Cuvier conjectures may be the rudiments or analogues of the baleen of the true whales. This Cetacean is now considered the type of a new genus, called by Lacepede ' Hyperoodon,'' and the only well-ascertained species is generally designated, after its original describer, Dale, 'Hyperoodon Dalei? The individual described by Dale was fourteen feet in length. Another described by Chemnitz, which was captured at Spitzbergen, measured twenty-five feet. A female, which was taken with her young one, near Harfleur, in 1788, was twenty-three feet in length. Nevertheless, the skeleton of the Hunterian specimen manifests all the characters of immature age, in the separation of the epiphyses; although it is to be observed that these parts are anchylosed less early in the Cetacea than in the land mammalia. The small bottle-nose whale of Hunter, is not the common dolphin, Delphinus delphis, L., as he supposed, but the Delphinus Tursio of Fabricius, as is shown by the skull and other parts which are preserved in the Hunterian Collection, as well as by the size of the specimen which Hunter describes. The Delphinus delphis is from six to seven feet in length, and has from forty-two to forty-seven teeth on each side of each jaw. The Delphinus Tursio attains the length often and eleven feet, and has from twenty-one to twenty-three teeth on each side of each jaw; which teeth are conical, but proportionally larger and more obtuse than in D. delphis.] * [This, as an average size, can only be attributed to the largest of the Balxnopterx or fin-backed whales. The usual length of the largest cachalots (Physeter macrocephalus, Shaw,) taken in the South Seas is about sixty-feet; but this size refers only to the males, for there is a remarkable disproportion in the size of the two sexes in this species of Cetacean, the full-grown female of which rarely exceeds thirty-five feet. The difference is principally in the length ofthe jaws, which are twice as long in the male as in the female, reminding one of the sexual characters afforded by the mandibles in the Lucani or stag-beetles.] 30 338 HUNTER ON THE ANIMAL GECONOMY. From my want of knowledge of the different genera of this tribe of animals, an incorrectness in the application of the anatomical account to the proper genus may be the consequence; for when they are of a certain size they are brought to us as porpoises; when larger they are called grampus or fin-fish. A tolerably correct anatomical description of each species, with an accurate drawing of the external form, would lead us to a knowledge df the different genera, and the species in each ; and, in order to forward so useful a work, I propose, at some future period, to lay before the Society descriptions and drawings of those which have come under my own observation. From some circumstances in their digestive organs we should be led to suppose that they were nearly allied to each other, and that there was not the same variety in this respect as in land animals. In the description of this order of animals I shall always keep in view their analogy to land animals, and to such as occasionally inhabit the water, as white bears, seals, manatees,* &c, with Ihe differences that occur. This mode of referring them to other animals better known will assist the mind in understanding the present subject. It is not, however, intended in this paper to give a particular account of the structure of all the animals of this order which I have had an opportunity of examining: I propose at present chiefly to confine myself to general principles, giving the great outlines as far as I am acquainted with them, minuteness being only necessary in the investigation of particular parts. In my account I shall pay some attention to the relations of men who have given facts without knowing their causes, whenever I find that such facts can be explained upon true principles of the animal ceconomy, but no further. This order of animals has nothing peculiar to fish, except living in the same element, and being endow-ed with the same powers of progressive motion as those fish that are intended to move with a considerable velocity; for I believe that all that come to the surface ofthe water (which this order of animals must do) have considerable progressive motion; and this reasoning we may apply to birds, for those which soar very high have the greatest progressive motion. Although inhabitants of the waters they belong to the same class as quadrupeds, breathing air, being furnished with lungs and all the other parts peculiar to the ceconomy of that class, and having warm blood ; for we make this general remark, that in the different classes of animals there is never any mixture of those * [The aquatic mammalia which Hunter includes under this name are associated by Cuvier, in consequence of the absence of hinder extremities, with the true Cetacea. They include the manatee of South America (Manatus), the dngong ofthe Indian Ocean and Red Sea (Halicore), and the manatee of the Arctic Seas (Rytina). They are all herbivorous, and differ in many anatomical particulars from the true cetacea, which are the subjects of Hunter's observations; connecting these mammalia with the quadrupeds ofthe Pachydermatous order.] OBSERVATIONS ON THE STRUCTURE, ETC. 339

parts which are essential to life, nor in their different mode of sensation.* I shall divide what is called the ceconomy of an animal: First, into those parts and actions which respect its internal functions, and on which life immediately depends, as growth, waste, repair, shifting or changing of parts, &c, the organs of respiration and secretion, in which we may include the powers of propagating the species. Secondly, into those parts and actions which respect external objects, and which are variously constructed, according to the kind of matter with which they are to be connected, whence they vary more than those of the first division. These are the parts for progressive motion, the organs of sense and the organs of digestion ; all of which either act upon, or are acted upon, by external matter. This variation from external causes in many instances influences the shape of the whole, or particular parts, even giving a peculiar form to some parts which belong to the first order of actions, as the heart, which in this tribe, in the seal, otter, &c, is flattened because the chest is flattened for the purpose of swimming. The contents of the abdomen are not only adapted to the external form; but their direction in the cavity is, in some instances, regulated by it. The anterior extremities, or fins, although formed of distinct parts, in some degree similar to the anterior extremities of some quadrupeds, being composed of similar bones placed nearly in the same manner, yet are so formed and arranged as to fit them for progressive motion in the water only. The external form of this order of animals is such as fits them for dividing the water in progressive motion, and gives them power to produce that motion in the same manner as those fish which move with a considerable velocity. On account of their inhabiting the water, their external form is more uniform than in animals of the same class which live upon land; the surface of the earth on which the progressive motion of the quadruped is to be performed being various and irregular, while the water is always the same. The form of the head or anterior part of this order of animals is commonly a cone, or an inclined plane, except in the spermaceti whale, in which it terminates in a blunt surface. This form of head increases the surface of contact to the same volume of water which it removes, lessens the pressure, and is better calculated to bear the resistance ofthe water through which the animal is to pass; probably on this account the head is larger than in quadrupeds, having more the proportion observed in fish, and swelling out laterally at the

* [That is, there is never any combination of the modifications of vital organs characteristic of two different classes of animals in the same species, as of a double heart of the mammal with the branchiae of a fish ; nor is the structure of the organ of hearing, or of any other sense characteristic of a higher class of vertebrata, ever combined with a modification of the vital organs peculiar to a lower class.] 340 HUNTER ON THE ANIMAL ECONOMY.

articulation of the lower jaw. This may probably be for the better catching their prey, as they have no motion of the head on the body, and this distance between the articulations of the jaw is somewhat similar to the swallow, goat-sucker, bat, &c, which may also be accounted for from their catching their food in the same manner as fish ; and this is rendered still more probable, since the form of the mouth varies according as they have or have not teeth. There is, however, in the whale tribe more variety in the form of the head than of any other part, as in the whalebone, bottle-nose, and spermaceti whales; though in this last it appears to owe its shape in some sort to the vast quantity of spermaceti lodged there, and not to be formed merely for the catching of its prey. From the mode of their progressive motion they have not the connexion between the head and body that is called the neck, as that would have produced an inequality inconvenient to progressive motion. The body behind the fins or shoulders diminishes gradually to the spreading of the tail; but the part beyond the opening of the anus is to be considered as tail, although to appearance it is a continuation of the body. The body itself is flattened laterally, and I believe the back is much sharper than the belly. The projecting part, or tail, contains the power that produces progressive motion and moves the broad termination, the motion of which is similar to that of an oar in sculling a boat; it supersedes the necessity of posterior extremities, and allows of the proper shape for swimming. That the form may be preserved as much as possible, we find that all the projecting parts found in land animals of the same class are either entirely wanting, as the external ear; are placed internally, as the testicles ; or are spread along under the skin, as the udder. The tail is flattened horizontally, which is contrary to that fish,* this position of tail giving the direction to the animal in the progressive motion of the body. I shall not pursue this circumstance further than to apply it to those purposes in the animal ceconomy for which this particular direction is intended. The two lateral fins, which are analogous to the anterior extremities in the quadruped, are commonly small, varying however in size, and seem to serve as a kind of oars. To ascertain the use of the fin on the back is probably not so easy, as the large whalebone and spermaceti whales have it not; one should otherwise conceive it is intended to preserve the animal from turning. I believe, like most animals, they are of a lighter colour on their

* [This difference in the position of the tail-fin relates chiefly to the difference between the whale and fish in the mode and amount of respiration; the warmblooded whale requiring a frequent ascent to the surface of the water to breathe the air, which the horizontal tail enables it to do. In the air-breathino- Ichthyosaurus, the presence of a pair of horizontal flattened posterior paddles,°for directing the snout to the surface of the water, enabled that extinct reptile to have lungs in combination with the vertical tail of the fish.] OBSERVATIONS ON THE STRUCTURE, ETC. 341

belly than on their back; in some they are entirely white on the belly, and this white colour begins by a regular determined line, as in the grampus, piked whale, &c.; in others, the white on the belly is gradually shaded into the dark colour ofthe back, as in the porpoise. I have been informed that some of them are pied upwards and downwards,* or have the divisions of colour in a contrary direction. The element in which they live renders certain parts which are of importance in other animals useless in them, gives to some parts a diflerent action, and renders others of less account. The puncta lachrymalia with the appendages, as the sac and duct, are in them unnecessary; and the secretion from the lachrymal gland is not water, but mucus, as it also is in the turtle; and we may suppose only in small quantity, the gland itself being small. The urinary bladder is smaller than in quadrupeds, and indeed there is not any apparent reason why whales should have one at all. The tongue is flat and but little projecting, as they neither have voice nor require much action of this part, in applying the food between the teeth for the purpose of mastication or deglutition, being nearly similar to fish in this respect as well as in their progressive motion. In some particulars they differ as much from one another as any two genera of quadrupeds I am acquainted with. The larynx, size of trachea, and number of ribs differ exceedingly The caecum is only found in some of them. The teeth in some are wanting. The blow-holes are two in number in many, in others only one. The whalebone and spermaceti are peculiar to particular genera; all which constitute great variations. In other respects we find an uniformity, which would appear to be independent of their living and moving only in the water, as in the stomach, liver, parts of generation of both sexes, and in the kidneys. In these last, however, I believe it depends in some degree upon their situation, although it is extended to other animals, the cause of which I do not understand. All animals have, I believe, a smell peculiar to themselves; how far this is connected with the other distinctions I do not know, our organs not being able to distinguish with sufficient accuracy. The smell of animals of this tribe is the same with that of the seal, but not so strong, a kind of sour smell, which the seal has while alive; the oil has the same smell with that of the salmon, herring, sprat, &c. The observations respecting the weight of the flesh of animals that swim, which I published in my Observations on the (Economy of certain parts of Animals,* are applicable to these also ; for the flesh in this tribe is rather heavier than beef: two portions of muscle of the same shape, one from the psoas muscle of the whale, the * [This irregular distribution of the dark and light shades is remarkable in the Phocxna Rissoana of Fred. Cuvier.] t [Pages 200, 281.] 30* 342 HUNTER ON THE ANIMAL C3CONOMY. other of an ox, when weighed in air, were both exactly 502 grains; but weighed in water, the portion of the whale was four grains heavier than the other. It is probable, therefore, that the necessary equilibrium between the water and the animal is produced by the oil, in addition to which the principal action of the tail is such as tends either to raise them or to keep them suspended in the water, according to the degree of force with which it acts. From the tail being horizontal, the motion of the animal, when impelled by it, is up and down : two advantages are gained by this, it gives the necessary opportunity of breathing, and elevates them in the water ; for every motion of the tail tends, as I said before, to raise the animal; and that this may be effected, the greatest motion of the tail is downwards, those muscles being very large, making two ridges in the abdomen; this motion of the tail raises the anterior extremity, which always tends to keep the body suspended in the water.

The bones alone, in many animals, when properly united into what is called the skeleton, give the general shape and character of the animal. Thus a quadruped is distinguished from a bird, and even one quadruped from another; it only requiring a skin to be thrown over the skeleton to make the species known. But this is not so decidedly the case with this order of animals, for the skeleton in them does not give us the true shape. An immense head, a small neck, few ribs, and in many a short sternum and no pelvis, with a long spine terminating in a point, require more than a skin being laid over them to give the regular and characteristic form ofthe animal. The bones ofthe anterior extremity give no idea ofthe shape of a fin, the form of which depends wholly upon its covering. The different parts of the skeleton are so inclosed, and the spaces between the projecting parts are so filled up, as to be altogether concealed, giving the animal externally an uniform and elegant form, resembling an insect enveloped in its chrysalis coat. The bones of the head are in general so large as to render the cavity which contains the brain but a small part of the whole; while in the human species and in birds this cavity constitutes the principal bulk of the head. This is, perhaps, most remarkable in the spermaceti whale; for, on a general view of the bones ofthe head, it is impossible to determine where the cavity of the skull lies till led to it by the foramen magnum occipitale. The same remark is applicable to the large w halebone and bottle-nose whale; but in the porpoise, where the brain is larger in proportion to the size of the animal, the skull makes the principal part of the head. Some of the bones in one genus differ from those of another. The lower jaw is an instance of this. In the spermaceti and bottlenose whales, the grampus, and the porpoise, the lower jaws, espe- OBSERVATIONS ON THE STRUCTURE, ETC. 343

cially at the posterior ends, resemble each other; but in both the large and small whalebone whales the shape differs considerably. The number of some particular bones varies likewise very much. The piked whale has seven vertebras in the neck, twelve which may be reckoned to the back, and twenty-seven to the tail, making forty-six in the whole.* In the porpoise there are five cervical vertebrae, and one common to the neck and back, fourteen proper to the back, and thirty to the tail; making in the whole fifty-one.f The small bottle-nose whale, caught near Berkeley, in the number of cervical vertebras resembled the porpoise: it had seventeen in the back, and thirty-seven in the tail; in all sixty.J In the porpoise four of the vertebras of the neck are anchylosed; and in every animal of this order which I have examined the atlas is by much the thickest, and seems to be made up of two joined together, for the second cervical nerve passes through a foramen in this vertebra. There is no articulation for rotatory motion between the first and second vertebras of the neck. The small bottle-nose whale had eighteen ribs on each side, the porpoise sixteen.§ The ends of the ribs that have two articulations, in the whole of this tribe, I believe, are articulated with the body of the vertebras above (or before) and with the transverse processes below (or of the succeeding vertebra), by the angles ; so that there is one vertebra common to the neck and back. In the large whalebone whale the first rib is bifurcated, and consequently articulated to two vertebras. The sternum is very flat in the piked whale, it is only one very short bone; and in the porpoise it is a good deal longer. In the small bottle-nose it is composed of three bones, and is of some * [In the skeleton ofthe Balxna rostrata preserved in the Museum ofthe College of Surgeons, there are only eleven pairs cf ribs, and two or three vertebrae are wanting at the extremity of the tail; but the total number of vertebrae could not have exceeded fifty. In the Balxnoptera Boops the number of vertebrae exceeds sixty ; there being seven cervical, fourteen dorsal, and from forty-one to forty-four caudal vertebrae. In the skeleton of this species, exhibited in the year 1827, in London, at Charing-cross, sixty-two vertebrae were distinguishable, and two or three more must have been concealed in the portion of the tail which had been preserved in situ. There were fourteen pairs of ribs. Cuvier, in the second edition of his ' Le<jons d'Anatomie Comparee,' assigns sixty-five vertebrae to the Balxnoptera Boops, of which fourteen are dorsal. In the Balxna Mysticetus there are forty-eight vertebras, viz., seven cervical, thirteen dorsal, and twenty-eight caudal.] f [In the skeletons which we have examined there are seven cervical vertebrae, the six first being anchylosed, thirteen costal or dorsal, and forty-six lumbar and caudal, making in all sixty-six.] X [In the Delphinus Tursio there are seven cervical, the two first being anchylosed, thirteen dorsal or costal vertebrae, corresponding with the pairs of ribs, and forty-three to the tail, making in all sixty-three vertebrae.] § [We have never found more than thirteen pairs of ribs in either the Delphinus Tursio, or Phocxna communis. In the Grampus there are seven cervical vertebrae, twelve costal, and forty-four lumbar and caudal; making in all sixty-three vertebrae. The Cachalot has sixty-one vertebrae, and fourteen pairs of ribs. The number of ribs in Balxnoptera rostrata is eleven pairs.] 344 HUNTER ON THE ANIMAL CECONOMY. length. In the piked whale the first rib, and in the porpoise the three first, are articulated with the sternum.* As a contraction, corresponding to the neck in quadrupeds, would have been improper in this order of animals, the vertebras of the neck are thin, to make the distance between the head and shoulders as short as possible; and in the small bottle-nose whale are only six in number.f The structure of the bones is similar to that of the bones of quadrupeds : they are composed of an animal substance, and an earth that is not animal; these seem only to be mechanically mixed, or rather the earth thrown into the interstices of the animal part. In the bones of fishes this does not seem to be the case, the earth in many fish being so united with the animal part as to render the whole transparent, which is not the case when the animal part is removed by steeping the bone in caustic alkali; nor is the animal part so transparent when deprived of the earth. The bones are less compact than those of quadrupeds that are similar to them. Their form somewhat resembles what takes place in the quadruped, at least in those whose uses are similar, as the vertebrae, ribs, and bones of the anterior extremities have their articulations in part alike, although not in all of them. The articulation of the lower jaw, of the carpus, metacarpus, and fingers are exceptions. The articulation of the lower jaw is not by simple contact either single or double, joined by a capsular ligament, as in the quadruped, but by a very thick intermediate substance of the ligamentous kind, so interwoven that its parts move on each other, in the interstices of which is an oil. This thick matted substance may answer the same purpose as the double joint in the quadruped.J The two fins are analogous to the anterior extremities of the quadruped, and are also somewhat similar in construction. A fin is composed of a scapula, os humeri, ulna, radius, carpus, and metacarpus, in which last may be included the fingers, because the number of bones are those which might be called fingers, although they are not separated, but included in one general covering with the metacarpus. They have nothing analogous to the thumb,§ and the

* [In our dissections we find five pairs of ribs articulated to the sternum in the porpoise. In the Hyperoodon there are also five pairs of sternal ribs. In the piked whale (Bal. rostrata) the floating extremities of the ten posterior pairs of ribs are attached to strong ligamentous decussating bands, which form a middle tendinous raphe, in the place of a sternum.] | [The true number of cervical vertebrae is seven in all the carnivorous Cetacea, as the holes for the transmission of the cervical nerves distinctly demonstrate. In the manatee there are only six. The more or less anchylosed condition of these vertebrae gives fixity to the head. The corresponding region ofthe spine in fish is rendered inflexible; and in the burrowing armadillos some ofthe cervical vertebrae are anchylosed, which structure in airthese cases is designed to afford the requisite power to the head for overcoming pressure.] X [See the Preparation No. 240, Physiological Series, Hunterian Museum.] § [i e. No. digit analogous in the opposable property which essentially characterizes a thumb; but the homologous digit, the fifth on the radial side,.is present OBSERVATIONS ON THE STRUCTURE, ETC. 345

number of bones in each is different: in the fore-finger there are five bones, in the middle and ring-finger seven, and in the little finger four. The articulation of the carpus, metacarpus, and fingers is different from that of the quadruped, not being by capsular ligament, but by intermediate cartilages connected to each bone. The cartilages between the different bones of the fingers are of considerable length, being nearly equal to one half of that of the bone: and this construction of the parts gives firmness with some degree of pliability to the whole. As this order of animals cannot be said to have a pelvis, they of course have no os sacrum, and therefore the vertebras are continued on to the end of the tail, but with no distinction between those of the loins and tail. But as those vertebras alone would not have had sufficient surface to give rise to the muscles requisite to the motion of the tail, there are bones added to the fore part of some of the first vertebras of the tail,* similar to the spinal processes on the posterior surface. From all these observations we may infer that the structure, formation, arrangement, and the union of the bones which compose the forms of parts in this order of animals are much upon the same principle as in quadrupeds. The flesh of muscles of this order of the animals is red, resembling that of most quadrupeds, perhaps more like that of the bull or horse than any other animal; some of it is very firm, and about the breast and belly it is mixed with tendon. Although the body and tail is composed of a series of bones connected together and moved as in fish, yet it has its movement produced by long muscles, with long tendons, which renders the body thicker while the tail at its stem is smaller than that of any other swimmer, whose principal motion is the same. Why this mode of applying the moving powers should not have been used in fish is probably not so easily answered ; but in fish the muscles of the body are of nearly the same length as the vertebras. The depressor muscles of the tail, which are similar in situation to the psoas, make two very large ridges on the lower part of the cavity of the belly, rising much higher than the spine, and the lower part of aorta passes between them, These two large muscles, instead of being inserted into two exin most cetacea. It has two phalanges in the Porpoise, and four phalanges in the Black-fish (Delphinus Globiceps). It is wanting in the Balxnoptera Australis.] * [These bones protect the great vascular trunk below, as the upper processes protect the spinal chord above, the bodies ofthe vertebrae. The former or inferior arches are termed by Geoffroy paraaux, or paravertebral elements; the latter the periaux, or perivertebral elements. I have proposed to denominate those which protect the vascular trunks ' aimapophyses;' those which protect the nervous trunk « neurapophyses.' The aimapophyses are articulated in the Cetacea at the interspaces of the bodies of the vertebra;, and connected with the intervertebral substance. In the dorsal vertebrae of the tortoise, and in the sacrum of the ostrich, the neurapophyses, or superior arches, are similarly placed with respect to the vertebral centres or bodies.] 346 HUNTER ON THE ANIMAL CECONOMY. tremities as in the quadruped, go to the tail, which may be considered in this order of animals as the two posterior extremities united into one. Their muscles a very short time after death lose their fibrous structure, become as uniform in texture as clay or dough, and even softer. This change is not from putrefaction, as they continue to be free from any offensive smell, and is most remarkable in those of the psoas muscles and those of the back.

Of the Construction of the Tail.

The mode in which the tail is constructed is perhaps as beautiful, as to the mechanism, as any part of the animal. It is wholly composed of three layers of tendinous fibres, covered by the common cutis and cuticle ; two of these layers are external, the other internal. The direction of the fibres of the external layers is the same as in the tail, forming a stratum about one-third of an inch thick;* but varying in this respect as the tail is thicker or thinner. The middle layer is composed entirely of tendinous fibres, passing directly across, between the two external ones above described, their length being in proportion to the thickness of the tail: a structure which gives amazing strength to this part. The substance of the tail is so firm and compact that the vessels retain their dilated state even when cut across; and this section consists of a large vessel surrounded by as many small ones as can come in contact with its external surface: which of these are arteries and which veins I do not know. The fins are merely covered with a strong condensed adipose membrane.

The fat of this order of animals, except the spermaceti, is what we generally term oil. It does not coagulate in our atmosphere, and is probably the most fluid of animal fats; but the fat of every different order of animals has not a peculiar degree of solidity, some having it in the same state, as the horse and bird. What I believe approaches nearest to spermaceti is the fat of ruminating animals, called tallow. The fat is differently situated in different orders of animals, probably for particular purposes; at least in some we can assign a final intention. In the animals which are the subject of the present paper it is found principally on the outside of the muscles, immediately under the skin, and is in considerable quantity. It is rarely to be met with in the interstices of the muscles, or in any of the cavities, such as the abdomen or about the heart. In animals of the same class living on land the fat is more dif- * [In the Bal. rostrata.] OBSERVATIONS ON THE STRUCTURE, ETC. 347

fused ; it is situated, more especially when old, in the interstices of muscles, even between the fasciculi of muscular fibres, and is attached to many ofthe viscera ; but many parts are free from fat, unless when diseased, as the penis, scrotum, testicle, eyelid, liver, lungs, brain, spleen, &c. In fish, its situation is rather particular, and is most commonly in two modes: in the one diffused through the whole body of the fish, as in the salmon, herring, pilchard, sprat, &c.; in the other, it is found in the liver only, as in all of the ray kind, cod, and in all those called white-fish, there being none in any other part of the body.* The fat of fish appears to be diffused through the substance of the parts which contain it, but is probably in distinct cells. In some of these fish, where it is diffused over the whole body, it is more in some parts than others, as on the belly of the salmon, where it is in larger quantity. The fat is differently inclosed in different orders of animals. In the quadruped, those of the seal kind excepted, in the bird, amphibia, and in some fish, it is contained in loose cellular membrane, as if in bags, composed of smaller ones, by which means the larger admit of motion on one another and on their connecting parts; which motion is in a greater or less degree, as is proper or useful. Where motion could answer no purpose, as in the bones, it is confined in still smaller cells. The fat is in a less degree in the soles of the feet, palms of the hands, and in the breasts of many animals. In this order of animals and the seal kind, as far as I yet know, it is disposed of in two ways: the small quantity found in the cavities of the body and interstices of parts is in general disposed in the same way as in quadrupeds; but the external, which includes the principal part, is inclosed in a reticular membrane, apparently composed of fibres passing in all directions, which seem to confine its extent, allowing it little or no motion on itself, the whole when distended forming almost a solid body. This, however, is not always the case in every part of animals of this order ; for under the head, or what may be rather called neck, of the bottle-nose, the fat is confined in larger cells, admitting of motion. This reticular membrane is very fine in some, and very strong and coarse in others, and even varies in different parts of the same animal. It is fine in the porpoise, spermaceti, and large whalebone whale; coarse in the grampus and small whalebone whale :f in all of them it is finest on the body, becoming coarser towards the tail, which is composed of fibres without any fat, which is also the case in the covering ofthe fins. This reticular net-work in the seal is very coarse; and in those which are not fat, when it collapses, it looks almost like a fine net with small meshes. This structure confines the animal to a

* The sturgeon is, however, an exception, having its fat in particular situations, and in the interstices of parts, as in other animals. | Where it is fine it yields the largest quantity of oil, and requires the least boiling. 348 HUNTER ON THE ANIMAL CECONOMY. determined shape, whereas in quadrupeds fat when in great quantity destroys all shape. The fat differs in consistence in different animals, and in different parts of the same animal, in which its situation is various. In quadrupeds some have the external fat softer than the internal, and that inclosed in bones is softest nearer to their extremities. Ruminating animals have that species of fat called tallow, and in their bones they have either hard fat, or marrow, or fluid fat, called neat's-foot oil. In this order of animals the internal fat is the least fluid, and is nearly of the consistence of hog's-lard ; the external is the common train oil. But the spermaceti whale differs from every other animal I have examined, having the two kinds of fat just mentioned, and another, which is totally different, called spermaceti, of which I shall give a particular account. What is called spermaceti is found everywhere in the body in small quantity, mixed with the common fat of the animal, bearing a very small proportion to the other fat. In the head il is the reverse, for there the quantity of spermaceti is large when compared to that of the oil, although they are mixed, as in the other parts of the body. As the spermaceti is found in the largest quantity in the head, and in what would appear on a slight view to be the cavity ofthe skull, from a peculiarity in the shape of that bone, it has been imagined by some to be the brain. -These two kinds of fat in the head are contained in cells, or cellular membrane, in the same manner as the fat in other animals; but besides the common cells there are larger ones, or ligamentous partitions, going across, the better to support the vast load of oil of which the bulk of the head is principally made up. There are two places in the head where this oil lies; these are situated along its upper and lower part, between them pass the nostrils, and a vast number of tendons going to the nose and different parts of the head. The purest spermaceti is contained in the smallest and least ligamentous cells: it lies above the nostril, all along the upper part of the head, immediately under the skin and common adipose membrane. These cells resemble those which contain the common fat in the other parts of the body nearest the skin. That which lies above the roof of the mouth, or between it and the nostril, is more intermixed with a ligamentous cellular membrane, and lies in chambers whose partitions are perpendicular. These chambers are smaller the nearer to the nose, becoming larger and larger towards the back part of the head, where the spermaceti is more pure. This spermaceti, when extracted cold, has a good deal the appearance of the internal structure of a water-melon, and is found in rather solid lumps. About the nose, or anterior part of the nostril, I discovered a great many vessels, having the appearance of a plexus of veins, some as large as a finger. On examining them, I found they were OBSERVATIONS ON THE STRUCTURE, ETC. 349

loaded with the spermaceti and oil, and that some had corresponding arteries. They were most probably lymphatics ;* therefore I should suppose that their contents had been absorbed from the cells ofthe head. We may the more readily suppose this from finding many ofthe cells or chambers almost empty; and as we may reasonably believe that this animal had been some time out ofthe seas in which it could procure proper food, it had perhaps lived on the superabundance of oil. The solid masses are what are brought home in casks for spermaceti. I found, by boiling this substance, that I could easily extract the spermaceti and oil which floated on the top from the cellular membrane. When I skimmed off* the oily part, and let it stand to cool, I found that the spermaceti crystallized, and the whole became solid ; and by laying this cake upon any spongy substance, as chalk, or on a hollow body, the oil drained all off, leaving the spermaceti pure and white. These crystals were only attached to each other by edges, forming a spongy mass ; and by melting this pure spermaceti, and allowing it to crystallize, it was reduced in appearance to half its bulk, the crystals being smaller and more blended, consequently less distinct. The spermaceti mixes readily with other oils, while it is in a fluid state, but separates or crystallizes whenever it is cooled to a certain degree, like two different salts being dissolved in water, one of which will crystallize with a less degree of evaporation than the other; or, if the water is warm and fully saturated, one ofthe salts will crystallize sooner than the other while the solution is cooling. I wanted to see whether spermaceti mixed equally well with the expressed oils of vegetables when warm, and likewise separated and crystallized when cold ; and on trial there seemed to be no difference. When very much diluted with the oil, it is dissolved or melted by a much smaller degree of heat than when alone; and this is the reason, perhaps, that it is in a fluid state in the living body. If the quantity of spermaceti is small in proportion to the other oil, it is perhaps nearly in that proportion longer in crystallizing; and when it does crystallize, the crystals are much smaller than those that are formed where the proportion of spermaceti is greater. From the slowness with which the spermaceti crystallizes when much diluted with its oil, from a considerable quantity being to be obtained in that way, and from its continuing for years to .crystallize, one would be induced to think that perhaps the oil itself is converted into spermaceti. It is most likely that if we could discover the exact form of the different crystals of oils, we should thence be able to ascertain both the different sorts of vegetable oils, expressed and essential, and the different sorts of animal oils, much better than by any other means ; in the same manner as we know salts by the forms into which they shoot

* [See the Preparation No. 8G2, Physiological Series, Hunterian Museum.] 31 350 HUNTER ON THE ANIMAL CECONOMY. The spermaceti does not become rancid or putrid nearly so soon as the other animal oils, which is most probably owing to the spermaceti being for the most part in a solid state; and I should suppose that few oils would become so soon rancid as they do if they were always preserved in that degree of cold which rendered them solid ; neither does this oil become so soon putrid as the flesh ofthe animal, and therefore, although the oil in the cells appeared to be putrid before boiling, it was sweet when deprived ofthe cellular substance. The spermaceti is rather heavier than the other oil. In this animal then we find two sorts of oil, besides the deeperseated fat, common to all of this class, one of which crystallizes with a much less degree of cold than the other, and of course requires a greater degree of heat to melt it, and forms, perhaps, the largest crystals of any expressed oil we know: yet the fluid oil of this animal will crystallize in an extreme hard frost much sooner than most essential oils, though not so soon as the expressed oils of vegetables. Camphire, however, is an exception, since it crystallizes in our warmest weather, and when melted with expressed oil of vegetables, if the oil is too much saturated for that particular degree of cold, crystallizes exactly like spermaceti. In the ox the tallow, and what is called neat's-foot oil, crystallize in different degrees of cold. The tallow congeals with rather less cold than the spermaceti, but the other oil is similar to what is called the train oil in the whale. I have endeavoured to discover the form of the crystals of different sorts of oil, but could never determine exactly what that was, because I could never find any of the crystals single, and by being always united the natural form was not distinct. It is the adipose covering from all of the whale kind that is brought home in square pieces, called flitches, and which, by being boiled, yields the oil on expression, leaving the cellular membrane. When these flitches have become in some degree putrid, there issue two sorts of oil; the first is pure, the last seems incorporated with part of the animal substance, which has become easy of solution from its putridity, forming a kind of butter. It is unctuous to the touch, ropy, coagulates, or becomes harder by cold, swims upom water, not being soluble in it; and the pure oil, separating in the same manner from this, swims above all. What remains after all the oil is extricated retains a good deal of its form, is almost wholly convertible into glue, and is sold for that purpose. The cellular, or rather what should be called the uniting membrane, in this order of animals is similar to that in the quadruped; we find it uniting muscle to muscle, and muscle to bone, for their easy motion on one another. The cellular membrane, which is the receptacle for the oil near the surface ofthe body, is in general very different from that in the quadruped, as has been already observed. OBSERVATIONS ON THE STRUCTURE, ETC. 351 Of the Skin. The covering of this order of animals consists of a cuticle and cutis. The cuticle is somewhat similar to that on the sole of the foot in the human species, and appears to be made up of a number of layers, which separate by slight putrefaction ; but this I suspect arises in some degree from there being a succession of cuticles formed. It has no degree of elasticity or toughness, but tears easily; nor do its fibres appear to have any particular direction. The internal stratum is tough and thick, and in the spermaceti whale its internal surface, when separated from the cutis, is just like coarse velvet, each pile standing firm in its place; but this is not so distinguishable in some ofthe others, although it appears rough from the innumerable perforations. It is the cuticle that gives the colour to the animal; and in parts that are dark I think I have seen a dirty-coloured substance washed away in the separation of the cuticle from the cutis, which must be a kind of rete mucosum. The cutis in this tribe is extremely villous on its external surface, answering to the rough surface of the cuticle, and forming in some parts small ridges, similar to those on the human fingers and toes. These villi are soft and pliable; they float in water, and each is longer or shorter, according to the size of the animal. In the spermaceti whale they were about a quarter of an inch long; in the grampus, bottle-nose, and piked whales, much shorter; in all, they are extremely vascular. The cutis seems to be the termination of the cellular membrane ofthe body more closely united, having smaller interstices and becoming more compact* This alteration in the texture is so sudden as to make an evident distinction between what is solely connecting membrane, and skin, and is most evident in lean animals; for in the change from fat to lean the skin does not undergo an alteration equal to what takes place in the adipose membrane, although it may be observed that the skin itself is diminished in thickness. In fat animals the distinction between skin and cellular membrane is much less, the gradation from the one to the other seeming to be slower; for the cells of both membrane and skin being loaded with fat, the whole has more the appearance of one uniform substance. The uniformity ofthe adipose membrane and skin is most observable in the whale, seal, hog, and the human species, and is not only visible in the raw, but in the dressed hides; for in dressed skins the external is much more compact in texture than the inner surface, and is in common very tough. * [That is to say, the denser external layer or dermis, and the more open cellular and fibrous structure below, which in the Cetacea is loaded with oil, are essentially modifications of one and the same structure. It is this combination ofthe dermal with the adipose tissues in the blubber ofthe whale which serves to retain the internal heat, and at the same time resists the external pressure, which must be occasionally enormous.] 352 HUNTER ON THE ANIMAL CECONOMY.

In some animals the cutis is extremely thick, and in some parts much more so than in others; where very thick it appears to be intended as a defence against the violence of their own species or other animals. In most quadrupeds it is muscular, contracting by cold, and relaxing by heat. Many other stimulating substances make it contract, but cold is probably that stimulus by which it was intended to be generally affected. The skin is extremely elastic in the greatest number of quadrupeds, and in its contracted state may be said to be rather too small for the body ; by this elasticity it adapts itself to the changes which are constantly taking place in the parts, and it is from the want of it that it becomes too large in some old animals. In all animals it is more elastic in some parts than others, especially in those where there is the greatest motion. How far these variations take place in the whale I do not exactly know ; but a loose elastic skin in this tribe would appear to be improper as an universal covering, considering the progressive motion of the animal, and the medium in which it moves; therefore it appears to be kept always on the stretch, by the adipose membrane being loaded with fat, which does not allow the skin to recede when cut. It is, however, more elastic at the setting on of the eyelids, round the opening of the prepuce, the nipples, the setting on of the fins, and under the jaw, to allow of motion in those parts ; and here there is more reticular, and less adipose membrane. But in the piked whale there is probably one ofthe most striking instances of an elastic cuticular contraction; for though the whole skin ofthe fore part ofthe neck and breast of the animal, as far down as the middle of the belly, be extremely elastic ; yet to render it still more so it is ribbed longitudinally, like a ribbed stocking, which gives an increased lateral elasticity. These ribs are, when contracted, about five-eighths of an inch broad, covered with the common skin of the animal; but in the hollow part of the rib it is of a softer texture, with a thinner cuticle. This part is possessed of the greatest elasticity; why it should be so elastic is difficult to say, as it covers the thorax, which can never be increased in size; yet there must be some peculiar circumstance in the ceconomy of the species requiring this structure, which we as yet know nothing of.* The skin is intended for various purposes. It is the universal covering given for the defence of all kinds of animals; and that it might answer this purpose well, it is the seat of one of the senses-f

* [A strong and extensive cutaneous muscle is intimately connected with the skin, but is separated by a loose cellular texture from the deep-seated muscles.] ' f [The skin ofthe Cetacea has been made the subject of a special and minute study by MM. Breschet and Roussel de Vauzeme, who distinguish in it, as in that of other Mammalia, six chief constituents, which either penetrate or are superimposed upon one another, as follows: 1. The derm or corium (le derme), a dense fibrous cellular texture, which contains and protects all the other parts of the skin. In the whale it is constantly white and opake, and its peripheral surface presents a series of papillae, the OBSERVATIONS ON THE STRUCTURE, ETC. 353 Of the Mode of catching their Food.

The mouths of animals are the first parts to be considered respecting nourishment or food, and are so much connected with everything relative to it as not only to give good hints whether the food is vegetable or animal, but also respecting the particular kind of either, especially of animal food. The mouth not only receives the food, but is the immediate instrument for catching it. As it is a compound instrument in many animals, having parts of various constructions belonging to it, I shall at present consider it in this tribe no further than as connected with their mode of catching food, and adapting and disposing it for being swallowed. It is probable that these animals do not require either a division ofthe food, or a mastication of it in the mouth, but swallow whatever they catch whole; for we do not find any of them furnished with parts capable of producing either effect. The mouth in most of this tribe is well adapted for catching the food; the jaws spread as they go back, making the mouth proportionally wider than in many other animals. There is a very great variety in the formation of the mouths

intervals of which are occupied by the epidermis, which forms for each a sheath. 2. The papillary bodies (les corps papillaires) consist of papillae covered by the derm. They have a nacreous lustre, and are several lines in length in the whale, but are much shorter in the common dolphin and porpesse. These papilla are composed of fibres penetrated by vessels; they originate from the subcutaneous nervous plexus, and return back again to the same; the derm serves merely as a sheath to the papiUae, the extremities of which exercise the sense of touch. 3. The sudorific apparatus (Pappareil sudorifique) consists of soft, elastic, spiral canals, which extend through the entire thickness of the derm, and open in the intervals ofthe papillae by an orifice generally closed by a small epidermic valve. 4. The inhalent apparatus (Pappareil eTinhalation) is formed by extremelv delicate canals, which are smooth, straight, silvery, branched, and very easily ruptured : they originate in a plexus extended in the dermis beneath the sudorific canals, anastomose together, and are provided with partitions. The lymphatic vessels have no connection with these canals, which communicate directly with the arteries and veins. They are absorbing canals. 5. The mucous apparatus (Vappareil blennogene). This is composed of secerning glands and excretory ducts, which open between the papillae like the orifices of the preceding canals. It is wholly contained in the derm, and produces a mucous material, which by desiccation (or condensation) becomes the cuticle. In the whales this cuticle acquires an extreme thickness: it is much thinner in the dolphins.a 6. The colorific apparatus (Pappareil chromatogene) is likewise composed of secerning glands and excretory ducts; it is situated in the first superior (peripheral) layers of the corium on the right and left sides of the outlet of the excretory ducts of the preceding apparatus, and it pours out ihe coloured product at the same point where the mucous matter is excreted, where it stains it.] a [In the Cachalot the external layer of cuticle is extremely fine, resemblin; gold-beaters' skin.] 31* 3.34 HUNTER ON THE ANIMAL CECONOMY.

of this tribe of animals, which we have many opportunities of knowing, from the head being often brought home when the other parts of the animal are rejected ; a circumstance which frequently leaves us ignorant of the particular species to which it belonged. Some catch their food by means of teeth, which are in both jaws, as the porpoise and grampus; in others, they are only in one jaw, as in the spermaceti whale;* and in the large bottle-nose whale, described by Dale, there are only two small teeth in the anterior part of the lower jaw. In the narwhale only two tusksf in the fore part of the upper jaw :J while in some others there are none at all. In those which have teeth in both jaws, the number in each varies considerably; the small bottle-nose had forty-six in the upper, and fifty in the lower ; and in the jaws of others there are only five or six in each. The teeth are not divisible into different classes, as in quadrupeds; but are all pointed teeth, and are commonly a good deal similar. Each tooth is a double cone, one point being fastened in the gum, the other projecting: they are, however, not all exactly of this shape. In some species of porpoise the fang is flattened, and ihin at its extremity; in the spermaceti whale the body of the tooth is a little curved towards the back part of the mouth ; this is also the case in some others. The teeth are composed of animal substance and earth, similar to the bony part of the teeth in quadrupeds. The upper teeth are commonly worn down upon the inside, the lower on the outside ; this, arises from the upper jaw being in general the largest. The situation ofthe teeth, when" first formed, and their progress afterwards, as far as I have been able to observe, is very different in common from those of the quadruped. In the quadruped the teeth are formed in the jaw, almost surrounded by the alveoli, or sockets, and rise in the jaw as they increase in length ; the covering ofthe alveoli being absorbed, the alveoli afterwards rise wilh the teeth ; covering the whole fang; but in this tribe the teeth appear to form in the gum,§ upon the edge of the jaw, and they

* [The large exserted teeth are confined to the lower jaw in this species, bat there are a few smaller teeth in the upper jaw of the cachalot. They are described by Mr. F. D. Bennett (Zoological Proceedings, December, 1836,) as sometimes occupying the bottom of the cavities which receive the teelh of the lower jaw, but generally corresponding to the intervals between them. They measure in length about three inches, and are slightly curved backwards, are developed in the gum, and have only a very slight attachment to the jaw-bone; in two instances, Mr. Bennett found eight on each side ofthe upper jaw.] f [I call these tusks to distinguish them from common teeth. A tusk is that kind of tooth which has no bounds set to its growth, excepting by abrasion, as the tusk ofthe elephant, boar, sea-horse, manatee, &c. X [The concealed rudimental tusk in the male narwhale (figured by Sir Everard Home in the Philosophical Transactions for 1813, p. 12G)rwas first discovered by Tichonius, and described by hirn in a dissertation entitled Mnwceroi Piscis haud Mmoceros, Copenhagen, 1706.] § [In the young porpesse the capsules and pulps ofthe teelh are always originally imbedded in the substance of the gum, where the first development of the OBSERVATIONS ON THE STRUCTURE, ETC. 355

either sink in the jaw as they lengthen, or the alveoli rise to inclose them: this last is most probable, since the depth ofthe jaw is also increased, so that the teeth appear to sink deeper-and deeper in the jaw. This formation is readily discovered in jaws not full grown ; for the teelh increase in number as the jaw lengthens, as in other animals. The posterior part of the jaw becoming longer, the number of teeth in that part increases, the sockets becoming shallower and shallower, and at last being only a slight depression. It would appear that they do not shed their teeth, nor have they new ones formed similar to the old, as is the case with most other quadrupeds, and also with the alligator. I have never been able to detect young teeth under the roots of the old ones ; and indeed the situation in which they are first formed makes it in some degree impossible, if the young teeth follow the same rule in growing with the original ones, as they probably do in most animals. If it is true that the whale tribe do not shed their teeth, in what way are they supplied with new ones corresponding in size writh the increased size of the jaw 1 It would appear that the jaw, as it increases posteriorly, decays at the symphysis, and while the growth is going on, there is a constant succession of new teeth, by which means the new-formed teeth are proportioned to the jaw. The same mode of growth is evident in the elephant, and in some degree in many fish ; but in these last the absorption ofthe jaw is from the whole of the outside along where the teeth are placed. The depth of the alveoli seems to prove this, being shallow at the back part of the jaw, and becoming deeper towards the middle, where they are the deepest, the teeth there having come to the full size. From this forwards they are again becoming shallower, the teeth being smaller, the sockets wasting, and at the symphysis there are hardly any sockets at all. This will make the exact number of teeth in any species uncertain. Some genera of this tribe have another mode of catching their food, and retaining it till swallowed, which is by means ofthe substance called whalebone. Of this there are two kinds known; one

tooth commences, by the formation of the crown. In this structure we see the analogy to the growth of whalebone, in which the base of the baleen-plates adhere throughout life to the gum only. A superficial or less scrupulous observer might have been led to describe the development ofthe teeth ofthe Cetacea according to the ordinary analogies ; but what are we to think of that writer who takes the opportunity to correct (!) Hunter's original and just description of this point, by informing his readers that the germs of the teeth are developed in an alveolar cavity in other mammalia'? and, who, in reference to the hypotheses suggested by Hunter to account for the lodgment of the teeth of the Cetacea in sockets, quotes only the first, for the purpose of contradicting it, asserting that the'cavity for the reception ofthe young teeth cannot be formed by the sinking of the teeth in it,' but avoids all mention of the second hypothesis, which Hunter states to be the most probable of the two, and which is the true one? (See Knox, in the Edinburgh Philosophical Transactions, vol. xi.,p.4ll.) Rapp, however, seems to adopt the first view; he says, the fangs of the teeth grow by degrees into the groove of the jaw: '• Nach und nach waehst dann die Wurzel in Rinne des Kicfers hinein." Cetaceen, p. 127.] 356 HUNTER ON THE ANIMAL CECONOMY. very large, probably from the largest whale yet discovered; the other from a smaller species.* This whalebone, which is placed on the inside of the mouth, and attached to the upper jaw, is one of the most singular circumstances belonging to this species, as they have most other parts in common with quadrupeds. It is a substance, I believe, peculiar to the whale, and of the same nature as horn, which I shall use as a term to express what constitutes hair, nails, claws, feathers, &c.; it is wholly composed of animal substance, and extremely elastic.f Whalebone consists of thin plates of some breadth, and in some of very considerable length, their breadth and length in some degree corresponding to one another; and when longest they are commonly the broadest, but not always so. These plates are very different in size in different parts of the same mouth, more especially in the large whalebone whale, whose upper jaw does not pass parallel upon the under, but makes an arch, the semidiameter of which is about one-fourth of the length of the jaw. The head in my possession is nineteen feet long, the semidiameter not quite five feet: if this proportion is preserved, those whales which have whalebone fifteen feet long must be of an immense size. These plates are placed in several rows, encompassing the outer skirts of the upper jaw, similar to teeth in other animals. They stand parallel to each other, having one edge towards the circumference of the mouth, the other towards the centre or cavity. They are placed near together in the piked whale, not being a quarter of an inch asunder where at the greatest distance, yet differing in this respect in different parts of the same mouth ; but in the great whale the distances are more considerable. The outer row is composed of the longest plates; and these are in proportion to the different distances between the two jaws, some being fourteen or fifteen feet long, and twelve or fifteen inches broad; but towards the anterior and posterior part of the mouth, they are very short; they rise for half a foot or more, nearly of equal breadths, and afterwards shelve offfrom their inner side until they come near to a point at the outer: the exterior of the inner rows are the longest, corresponding to the termination of the declivity of the outer, and become shorter and shorter till they hardly rise above the gum. The inner rows are closer than the outer, and rise almost perpendicularly from the gum, being longitudinally straight, and have less of the declivity than the outer. The plates of the outer row laterally are not quite flat, but make a serpenline line; more especially in the piked whale the outer edge is thicker than the inner. All round the line made by their outer edges, runs a small white bead, which is formed along with the whalebone, and wears down with it. The smaller plates are nearly of an equal thickness upon * [The largest species of whale yet discovered is distinguished by the smallsized baleen-plates, and is the Balxnoptera Boops, a3 was before observed.] | From this it must appear that the term bone is an improper one. OBSERVATIONS ON THE STRUCTURE, ETC. 357

both edges. In all of them, the termination is in a kind of hair, as if the plate was split into innumerable small parts, the exterior being the longest and strongest. The two sides of the mouth composed of these rows meet nearly in a point at the tip of the jaw, and spread or recede latterally from each other as they pass back ; and at their posterior ends, in the piked whale, they make a sweep inwards, and come very near each other, just before the opening of the oesophagus. In the piked whale, there were above three hundred in the outer rows on each side of the mouth. Each layer terminates in an oblique surface, which obliquity inclines to the roof of the mouth, answering to the gradual diminution of their length; so that the whole surface composed of these terminations, forms one plane rising gradually from the roof of the mouth; from this obliquity of the edge of the outer row, we may in some measure judge of the extent of the whole base, but not exactly, as it makes a hollow curve, which increases the base. The whole surface resembles the skin of an animal covered with strong hair, under which surface the tongue must immediately lie when the mouth is shut: it is of a light brown colour in the piked whale, and is darker in the large whale. In the piked whale, when the mouth is shut, the projecting whalebone remains entirely on the inside of the lower jaw, the two jaws meeting everywhere along their surface ; But how this is effected in the large whale I do not certainly know, the horizontal plane made by the lower jaw being straight, as in the piked whale; but the upper jaw, being an arch, cannot be hid by the lower. I suppose therefore that a broad upper lip, meeting as low as the lower jaw, covers the whole ofthe outer edges of the exterior rows. The whalebone is continually wearing down, and renewing in the same proportion, except when the animal is growing it is renewed faster and in proportion to the growth. The formation of the whalebone is extremely curious, being in one respect similar to that of the hair, horns, spurs, &c. ; but it has besides another mode of growth and decay equally singular. These plates form upon a thin vascular substance, not immediately adhering to the jaw-bone, but having a more dense substance between, which is also vascular. This substance, which may be called the nidus of the whalebone, sends out (the above) thin broad processes, answering to each plate, on which the plate is formed, as the cock's spur, or the bull's horn on the bony core, or a tooth on its pulp ; so that each plate is necessarily hollow at its growing end, the first part of the growth taking place on the inside of this hollow. Besides this mode of growth, which is common to all such substances, it receives additional layers on the outside, which are formed upon the above-mentioned vascular substance extended along the surface of the jaw. This part also forms upon it a semi- 358 HUNTER ON THE ANIMAL CECONOMY. horny substance between each plate, which is very white, rises with the whalebone, and becomes even with the outer edge ofthe jaw, and the termination of its outer part forms the bead abovementioned. This intermediate substance fills up the spaces between the plates as high as the jaw, acts as abutments to the whalebone, or is similar to the alveolar processes of the teeth, keeping them firm in their places. As both the whalebone and intermediate substance are constantly growing, and as we must suppose a determined length necessary, a regular mode of decay must be established, not depending entirely on chance or the use it is put to. In its growth three parts appear to be formed: one from the rising core, which is the centre; a second on the outside; and a third,being the intermediate substance. These appear to have three stages of duration; for that which forms on the core I believe makes the hair, and that on the outside makes principally the plate of whalebone; this, when got a certain length, breaks off, leaving the hair projecting, becoming at the termination very brittle; and the third, or intermediate substance, by the time it rises as high as the edge of the skin of the jaw, decays and softens away like the old cuticle of the sole of the foot when steeped in water.* The use of the whalebone, I should believe, is principally for the retention of the food till swallowed, and do suppose the fish they catch are small when compared with the size of the mouth. The oesophagus, as in other animals, begins at the fauces, or posterior part of the mouth ; and, although circular at this part, is soon divided into two passages by the epiglottis passing across it, as will be described hereafter. Below its attachment to the trachea, it passes down in the posterior mediastinum, at some distance from the spine, to which it is attached by a broad part of the same membrane, and its anterior surface makes the posterior part of the cavity behind the pericardium. Passing through the diaphragm it enters the stomach, and is lined with a very thick, soft, and white cuticle, which is continued into the first cavity of the stomach. The inner or true coat is white, of a considerable density, and not muscular, but thrown into large longitudinal folds by the contraction of the muscular fibres of the oesophagus, which are very strong. It is very glandular; for on its inner surface, especially near the fauces, orifices of a vast number of glands are visible. The oesophagus is larger in proportion to the bulk of the animal than in the quadruped, although not so much so as it usually is in fish, which we may suppose swallow their food much in the same way. In the piked whale it was three inches and a half wide.

* [The supplementary note appended, in the second edition of the 'Lecons d'Anatomie Comparee,' torn, iii., p. 376, to the imperfect description given by Cuvier ofthe formation ofthe whalebone, is a mere condensation of the minute, original, and accurate account in the text: to which, however, no reference is made by M. Duvernoy.] OBSERVATIONS ON THE STRUCTURE, ETC. 359

The stomach, as in other animals, lies on the left side of the body, and terminates in the pylorus towards the right. In the piked whale the duodenum passes down on the right side, very much as in the human subject, excepting that it is more exposed, from the colon not crossing it. It lies on the right kidney, and then passes to the left side behind the ascending part of the colon and root of the mesentery, comes out on the left side, and getting on the edge of the mesentery becomes a loose intestine, forming the jejunum. In this course behind the mesentery it is exposed, as in most quadrupeds, not being covered by it as in the human. The jejunum and ileum pass along the edge ofthe mesentery downwards to the lower part of the abdomen. The ileum near the lower end makes a turn towards the right side, and then mounting upwards, round the edge of the mesentery, passes a little way on the right, as high as the kidneys and there enters the colon or cascum. The caecum lies on the lower end of the kidney, considerably higher than in the human body, which renders the ascending part of the colon short. The cascum is about seven inches long, and more like that of the lion or seal than of any other animal I know. The colon passes obliquely up the right side, a little towards the middle of the abdomen, and when as high as the stomach crosses to the left and acquires a broad mesocolon; at this part it lies upon the left kidney, and in its passage down gets more and more to the middle line of the body. When it has reached the lower part of the abdomen it passes behind the uterus and along with the vagina in the female, between the two testicles and behind the bladder and root of the penis in the male, bending down to open on what is called the belly of the animal, and in its whole course it is gently convoluted. In those which have no cascum, and therefore can hardly be said to have a colon, the intestine before its termination in the rectum makes the same kind of sweep round the other intestines as the colon does where there is a caecum. The intestines are not large for the size of the animal, not being larger in those of eighteen or twenty-four feet long than in the horse, the colon not much more capacious than the jejunum and ileum, and very short; a circumstance common to carnivorous animals. In the piked whale the length from the stomach to the cascum is twenty-eight yards and a half, length of cascum seven inches, of the colon to the anus two yards and three-quarters. The small intes'tines are just five times the length of the animal, the colon with the caecum a little more than one-half the length. Those parts that respect the nourishment of this tribe do not all so exactly correspond as in land animals, for in these one in some degree leads to the other. Thus the teeth in the ruminating tribe point out the kind of stomach, cascum, and colon; while in others, as the horse, hare, lion, &c, the appearances ofthe teeth only give us the kind of colon and caecum ; but in this tribe, whether teeth or no teeth, the stomachs do not vary much, nor does the circumstance 360 HUNTER ON THE ANIMAL CECONOMY.

of caecum seem to depend on either teeth or stomach. The circumstances by which from the form of one part we judge what others are, fail us here: but this may arise from not knowing all the circumstances. The stomach in all that I have examined consists of several bags continued from the first on the left towards the right, where the last terminates in duodenum. The number is not the same in all: for in the porpoise, grampus, and piked whale there are five; in the bottle-nose (Hyperoodon) seven. Their size respecting one another differs very considerably, so that the largest in one species may in another be only the second. The two first in the porpoise, bottle-nose, and piked whale are by much the largest; the others are smaller, although irregularly so. The first stomach has, I believe, in all very much the shape of an egg, with the small end downwards. It is lined everywhere with a continuation ofthe cuticle from the oesophagus. In the porpoise the oesophagus enters the superior end ofthe stomach. In the piked whale its entrance is a little way on the posterior part of the upper end, and is oblique. The second stomach in the piked whale is very large, and rather longer than the first. It is of the shape of the italic S, passing out from the upper end of the first on its right side, by nearly as large a beginning as the body7 ofthe bag. In the porpoise it by no means bears the same proportion to the first, and opens by a narrower orifice; then passing down along the right side of the first stomach, it bends a little outwards at the lower end, and terminates in the third. Where this second stomach begins, the cuticle of the first ends.* The whole of the inside of this stomach is thrown into unequal rugos, appearing like a large irregular honeycomb. In the piked whale the rugae are longitudinal, and in many places very deep, some of them being united by cross bands ; and in the porpoise the folds are very thick, massy, and indented into one another.! This stomach opens into the third by a 'round contracted orifice, which does not seem to be valvular. The third stomach is by much the smallest, and appears to be only a passage between the second and fourth. It has no peculiar

* [The lining membrane of the first stomach in the porpesse sends off a number of irregular projections, where it surrounds the opening into the second stomach, whereby that opening is rendered valvular, and adapted to prevent the passage of anything but fluids or substances of very small size. The first stomach, therefore, serves not only as a reservoir, but the food undergoes a considerable change in it, probably by the action ofthe gastric secretion of ihe second cavity regurgitated into it. Thus the bones offish have been found in the first cavity with all the flesh dissolved, and the bones themselves softened by the removal of their earthy constituent. See Preparation No. 569 e. Physiological Series, Hunterian Museum.] f [It is to this stomach that ihe pneumogastric nerves are principally distributed ; the thick and soft lining substance presents, according to the microscopical researches of Sir David Brewster, a peculiar structure, consisting of closely aggregated minute tubes placed perpendicularly between the smooth internal mucous membrane and ihe vascular tunic which immediately lines the muscular coat.] OBSERVATIONS ON THE STRUCTURE, ETC. 361

structure on the inside, but terminates in the fourth by nearly as large an opening as its beginning. In the porpoise it is not above one, and in the bottle-nose about five, inches long. The fourth stomach is of a considerable size; but a good deal less than either the first or second. In the piked whale it is not round, but seems flattened between the second and fifth. In the porpoise it is long, passing in a serpentine course almost like an intestine. The internal surface is regular, but villous, and opens on its right side into the fifth by a round opening smaller than the entrance from the third. The fifth stomach is in the piked whale round, and in the porpoise oval ;* it is small, and terminates in the pylorus, which has little of a valvular appearance. Its coats are thinner than those ofthe fourth, having an even inner surface, which is commonly tinged with bile. The piked whale, and, I believe, the large whalebone whale, have a cascum ; but it is wanting in the porpoise, grampus, and bottlenose whale.f The structure of the inner surface of the intestine is in some very singular, and different from that of the others. The inner surface of the duodenum in the piked whale is thrown into longitudinal rugae, or valves, which are at some distance from each other, and these receive lateral folds. The duodenum in the bottle-nose swells out into a large cavity, and might almost be reckoned an eighth stomach ; but as the gall-ducts enter it I shall call it duodenum. The inner coat of the jejunum, and ileum, appears in irregular folds, which may vary according as the muscular coat ofthe intestine acts : yet I do not believe that their form depends entirely on that circumstance, as they run longitudinally, and take a serpentine course when the gut is shortened by the contraction of the longitudinal muscular fibres. The intestinal canal of the porpoise has several longitudinal folds of the inner coat passing along it through the whole of its length. In the bottle-nose the inner coat, through nearly the whole track of the intestine, is thrown into large cells, and these again subdivided into smaller; the axis of which cells is not perpendicular to a transverse section of the intestine, but oblique, forming pouches with the mouths downwards, and acting almost like valves when anything is attempted to be passed in a contrary direction ; they begin faintly in the duodenum, before it makes its quick turn, and terminate near the anus.J The colon

* [This part we regard as the dilated duodenum, since the gall-ducts terminate in it, and consequently reckon but four compartments in the stomach of the porpesse.] t [In all the vegetable feeding Cetacea there is a caecum, but it is small. In the dugong it is of a simple conical form, and very muscular. In the manatee the caecum is bifurcate.] X [See the Preparations, Nos. 709, 710, 711, 712, Physiological Series, Hunterian Museum.] 32 362 HUNTER ON THE ANIMAL CECONOMY. and rectum have the rugae very flat, which seems to depend entirely on the contraction of the gut. The rectum in the piked whale near the anus, appears for four or five inches much contracted, is glandular, covered by a soft cuticle, and the anus small. I never found any air in the intestines of the tribe; nor indeed in any of the aquatic animals. The mesenteric artery anastomoses by large branches. There is a considerable degree of uniformity in the liver of this tribe of animals. In shape it nearly resembles the human, but is not so thick at the base, nor so sharp at the lower edge, and is probably not so firm in its texture. The right lobe is the largest and thickest, its falciform ligament broad, and there is a large fissure between the two lobes, in which the round ligament passes. The liver towards the left is very much attached to the stomach, the little epiploon being a thick substance. There is no gall-bladder. The hepatic duct is large, and enters the duodenum about seven inches beyond the pylorus.* The pancreas is a very long, flat body, having its left end attached to the right side of the first cavity of the stomach: it passes across the spine at the root of the mesentery, and near to the pylorus joins the hollow curve of the duodenum, along which it is continued, and adheres to that intestine, its duct entering that of the liver near the termination in the gut. Although this tribe cannot be said to ruminate, yet in the number of stomachs they come nearest to that order ; but here I suspect that the order of digestion is in some degree inverted. In both the ruminants, and this tribe, I think it must be allowed that the first stomach is a reservoir. In the ruminants the precise use of the second and third stomachs is perhaps not known; but digestion is certainly carried on in the fourth; while in this tribe, I imagine, digestion is performed in the second,! and the use of the third and fourth-is not exactly ascertained. The caecum and colon do not assist in pointing out the nature of the food and mode of digestion in this tribe. The porpoise, which has teeth and four cavities to the stomach, has no caecum, similar to some land animals, as the bear, badger, racoon, ferret, polecat, &c; neither has the bottle-nose a cascum which has only two small teeth in the lower jaw; and the piked whale, which has no teeth, has a

* [In the dugong there is a gall-bladder of the usual dimensions, which is chiefly peculiar for the mode in which the bile is conveyed to it; in other mammalia this takes place by a communication between the hepatic and cystic duct?, at some distance from the bladder, but here two large hepatic ducts open directly into the neck ofthe gall-bladder, in the same way as the ureters terminate in the urinary bladder. The cystic duct, which fulfils the office of the ductus communis, proceedstothe duodenum, and becomes slightly dilated, before it enters that intestine. The manatee has also a gall-bladder, but it is wanting in the northern manatee or Rytina.] | [It is doubtless performed in a great part by the secretion ofthe second, but as before observed, the act is far advanced in the first cavity.] OBSERVATIONS ON THE STRUCTURE, ETC. 363

cascum, almost exactly like the lion, which has teeth and a very different kind of stomach. The food of the whole of this tribe, I believe, is fish; probably each may have a particular kind of which it is fondest, yet does not refuse a variety. In the stomach of the large bottle-nose I found the beaks of some hundreds of cuttle-fish. In the grampus I found the tail of a porpoise; so that they eat their own genus. In the stomach of the piked whale I found the bones of different fish, but particularly those of the dog-fish.* From the size of the oesophagus we may conclude that they do not swallow fish so large in proportion to their size as many fish do that we have reason to believe take their food in the same way; for fish often attempt to swallow what is larger than their stomachs can at one time contain, and part remains in the oesophagus till the rest is digested. The epiploon on the whole is a thin membrane; on the right side it is rather a thin network,! though on the left it is a complete membrane, and near to the stomach of the same side becomes of a considerable thickness, especially between the two first bags of the stomach. It has little or no fat, except what slightly covers the vessels in particular parts. It is attached forwards, all along to the lower part of the different bags constituting the stomach, and on the right to the root of the mesentery between the stomach and transverse arch of the colon, first behind to the transverse arch of the colon and root of the mesentery, then to the posterior surface ofthe left or first bag of the stomach, behind the anterior attachment. In some of this tribe there is the usual passage behind the vessels going to the liver, common to all quadrupeds I am acquainted with; but in others, as the small bottle-nose, there is no such passage, by which the cavity behind the stomach in the epiploon of this animal becomes a circumscribed cavity. The spleen, in the piked whale, is involved in the epiploon, and is very small for the size of the animal. There are in some, as the porpoise, one or two small ones, about the size of a nutmeg, often smaller, placed in the epiploon behind the other.J These are sometimes met with likewise in the human body. The kidneys in the whole of this tribe of animals are conglomerated, being made up of smaller parts, which are only connected by cellular membrane, blood-vessels, and ducts, or infundibula ; but not partially connected by continuity of substance, as in the human body, the ox, &c.: every portion is of a conical figure, whose apex is placed towards the centre of the kidney, the base making the external surface; and each is composed of a cortical and tubular substance, the tubular terminating in the apex, which apex makes

* [In the stomach of the porpesse I have found the bones of an eel, and of a flounder; these were in the first cavity. The great sperm whale is nourished principally by molluscaof the class of Cephalopods, and their beaks seem to form the nuclei ofthe intestinal concretions, called 'ambergris.'] f [It presents this reticulate structure in the otter.] X [The smaller accessory spleens are sometimes four, five, or six in number.] 364 HUNTER ON THE ANIMAL CECONOMY. the mamilla. Each mamilla has an infundibulum, which is long, and at its beginning wide, embracing the base of the mamilla, and becoming smaller. These infundibula unite at last, and form the ureter. The whole kidney is an oblong, flat body, broader and thicker at the upper end than the lower, and has the appearance of being made up of different parts placed close together, almost like the pavement of a street. The ureter comes out at the lower end, and passes along to the bladder, which it enters very near the urethra. The bladder is oblong, and small for the size of the animal. In the female the urethra passes along to the external sulcus or vulva, and opens just under the clitoris, much as in the human subject. Whether being inhabitants of the water makes such a construction of kidney necessary I cannot say ; yet one must suppose it to have some connection with such situation, since we find it almost uniformly take place in animals inhabiting the water, whether wholly, as this tribe, or occasionally, as the manatee, seal, and white bear: there is, however, the same structure in the black bear, which I believe never inhabits the water.* This, perhaps, should be considered in another light, as Nature keeping up to a certain uniformity in the structure of similar animals; for the black bear in construction of parts is, in every other respect as well as this, like the white bear. The capsulas renales are small for the size of the animal, when compared to the human, as indeed they are in most animals. They are flat, and of an oval figure; the right lies on the lower and posterior part ofthe diaphragm, somewhat higher than the kidney; the left is situated lower down, by the side of the aorta, between it and the left kidney. They are composed of two substances, the external having the direction of its fibres or parts towards the centre; the internal seeming more uniform, and not having so much of the fibrous appearance. The blood of animals of this order is, I believe, similar to that of quadrupeds, but I have an idea that the red globules are in larger proportion. I will not pretend to determine how far this may assist in keeping up the animal heat, but as these animals may be said to live in a very cold climate or atmosphere, and such as readily carries off heat from the body, they may want some help of this kind. It is certain that the quantity of blood in this tribe and in the seal is comparatively larger than in the quadruped, and therefore probably amounts to more than that of any other known animal.

* [In the beaver and other Rodentia of amphibious habits, the kidney presents a simple undivided form ; and although in the manatee and rytina the kidney presents the subdivided type of formation, yet it has a smooth, unbroken external surface in the dugong, and the papillae form two lateral series opening into a single elongated pelvis.] OBSERVATIONS OF THE STRUCTURE, ETC. 365

This tribe differs from fish in having the red blood carried to the extreme parts of the body, similar to the quadruped. The cavity of the thorax is composed of nearly the same parts as in the quadruped, but there appears to be some difference, and the varieties in the different genera are greater. The general cavity is divided into two, as in the quadruped, by the heart and mediastinum. The heart in this tribe and in the seal is probably larger in proportion to their size than in the quadruped, as also the blood-vessels, more especially the veins. The heart is inclosed in its pericardium, which is attached by a broad surface to the diaphragm, as in the human body. It is composed of four cavities,* two auricles, and two ventricles : it is more flat than in the quadruped, and adapted to the shape of the chest. The auricles have more fasciculi, and these pass more across the cavity from side to side than in many other animals ; besides, being very muscular they are very elastic, for being stretched they contract again very considerably. There is nothing uncommon or particular in the structure of the ventricles, in the valves of the ventricles, or in that of the arteries. The general structure of the arteries resembles that of other animals, and where parts are nearly similar the distribution is likewise similar. The aorta forms its usual curve, and sends off the carotid and subclavian arteries.f

* As the circulation is a permanent part of the constitution respecting the class to which the animal belongs, and as the kind of heart corresponds with the circulation, these should be considered in the classing of animals. Thus we have animals whose hearts have only one cavity, others with two, three, and four cavities. . f [Both the aorta and pulmonary artery are considerably dilated above their origin in the narwhale, according to Albers, Mayer, and Rapp(Cetaceen, p. 158,) In the porpoise the aorta sends off, as usual, first the two coronary arteries, then three branches from the convexity of the arch. The first of these is the largest; it sends off the posterior thoracic and then the right carotid, and lastly, divides into the right subclavian and internal mammary arteries. The second branch sends off the left carotid, subclavian, and internal mammary arteries; but the left posterior thoracic arises, as a third branch, immediately from the arch of the aorta. Notwithstanding the shortness ofthe neck, the common carotid, on each side, sends off a branch, as in most mammalia, before dividing into the external and internal carotids; and the subordinate branches of both these vessels form plexuses in various parts of the head, especially at the basis cranii,and around the optic nerve. The abdominal aorta lies deep in the cleft between the right and left psoas muscles. It gives off the caeliac, and close to it the superior mesenteric, then, at a greater distance, a small inferior mesenteric artery; also a right and left renal artery, which, in the true Cetacea, enter the upper or anterior extremity of the kidney, and subdivides to distribute branches to the oifferent lobules, like the stalk of a bunch of grapes. The spermatic arteries are quickly resolved into plexuses. The lumbar arteries are given off as usual in pairs ; and a little anterior to the pelvic bones the aorta divides into two hypogastric arteries (which send off the umbilical arteries to the sides of the bladder), and a middle caudal artery, which is the largest, and passes, as a continuation of the aortic trunk, through the arches of the inferior spines. There are no branches analogous to common iliac and crural arteries.] 32* 3G6 HUNTER ON THE ANIMAL CECONOMY. Animals of this tribe, as has been observed, have a greater proportion of blood than any other known, and there are many arteries apparently intended as reservoirs, where a larger quantity of arterial blood seemed to be required in a part, and vascularity could not be the only object. Thus we find that the intercostal arteries divide into a vast number of branches, which run in a serpentine course between the pleura and the ribs, and their muscles, making a thick substance somewhat similar to that formed by the spermatic artery in the bull. Those vessels everywhere lining the sides of the thorax pass in between the ribs near their articulation, and also behind the ligamentous attachment of the ribs, and anastomose with each other. The medulla spinalis is surrounded with a network of arteries in the same manner, more especially where it comes out from the brain, where a thick substance is formed by their ramifications and convolutions; and these vessels most probably anastomose with those of the thorax.* The subclavian artery in the piked whale, before it passes over the first rib, sends down into the chest arteries which assist in forming the plexus on the inside of the ribs ;f I am not certain but the internal mammary arteries contribute to form the anterior part of this plexus. The motion of the blood in such must be very slow, the use of which we do not readily see. The descending aorta sends off the intercostals, which are very large, and give branches to this plexus; and when it has reached the abdomen, it sends off, as in the quadruped, the different

* [Tyson, who was the first discoverer and describer of this structure (Anatomy of a Porpesse, p. 32, pi. 2, fig. 7, 4to., 1680), speaks of it as a ' glandulous body,1 but describes it as a curious contexture of blood-vessels variously contorted and winding, emerging from the medulla spinalis at the holes where the nerves come out between the ribs ; and he observes, " the same substance likewise for a good thickness covered the medulla spinalis throughout." Hunter first determined the exact nature of this structure, and that it was a reservoir of arterial blood. It is from this reservoir that the central axis of the nervous system receives its appropriate stimulus, and the powerful muscles of the tail their supply of oxygenated blood during the period of submersion and consequent interruption ofthe respiratory function. M. Breschet, in a treatise ex professo on this structure, gives some beautiful figures of it. (See Histoire Anatomique et Physiologiqued'un Organe de. Nature vasculaire decouvert dans les Cetaces, par G. M. Breschet; 4to. 183C). He detected it in the Delphinus Delphis and Delphinus Globiceps, and in a fcetus of the Balxna Mysticetus,- but in reasoning on the physiology of the great arterial reservoirs which thus seem to be common to the true Cetacea, it is necessary to bear in mind that the structure does not exist in the herbivorous Cetacea.] f [It also gives off external thoiacics to the pectoral muscles, a subscapular branch, and one to the supraspinal fossa : these arteries supply the moving powers ofthe fin: the trunk then divides in two branches, which almost immediately subdivide, and form plexuses upon the humerus, which are expended in nourishing the bones and their ligaments and the enveloping integument. This disposition is but remotely analogous to the condition ofthe axillary artery in the slow lemurs and sloth, where a plexus is formed by a sudden subdivision ofthe trunk into numerous small branches, which after a brief course reunite into the common trunk, which then proceeds, as brachial artery, to supply the muscles of the forearm and hand.] OBSERVATIONS ON THE STRUCTURE, ETC. 367

branches to the viscera and the lumbar arteries, which are likewise very large for the supply of that vast mass of muscles which moves the tail. In our examination of particular parts, the size of which is generally regulated by that of the whole animal, if we have only been accustomed to see them in those which are small or middle-sized, we behold them with astonishment in animals so far exceeding the common bulk as the whale. Thus the heart and aorta of the spermaceti whale appeared prodigious, being too large to be contained in a wide tub, the aorta measuring a foot in diameter. When we consider these as applied to the circulation, and figure to ourselves that probably ten or fifteen gallons of blood are thrown out at one stroke, and moved with an immense velocity through a tube of a foot diameter, the whole idea fills the mind with wonder. The veins, I believe, have nothing particular in their structure, excepting in parts requiring a peculiarity, as in the folds of the skin on the breast in the piked whale, where their elasticity was to be increased. •

The larynx in most animals living on land is a compound organ, adapted both for respiration, deglutitiou, and sound, which last is produced in the actions of respiration; but in this tribe the larynx I suppose is only adapted to respiration, as we do not know that they have any mode of producing sound.t It is composed of os hyoides, thyroid, cricoid, and two arytenoid cartilages, with the epiglottis. It varies very much in structure and size, when compared in animals of different genera. These cartilages were much smaller in the bottle-nose of twenty-four feet

* [Hunter has previously noticed the great capacity of the veins; they are also remarkable for their number and the immense plexuses which they form in different parts ofthe body, but above all for the almost total absence of valves. Tyson has given a figure of the extensive venous plexus situated on the membrane investing the psoas muscles (ibid., pi. 1, fig. 2, H.), and these have recently occupied the attention of Breschet, loc. cit., and V. Baer (Acta Acad. Nat. Cur., vol. xvii., p. 1,1834). The inferior and superior venae cavae are not brought into communication by the vena azygos, as in other mammalia ; such veins in the usual situation in the chest would have been subject to compression between the arterial plexuses and the lungs. The venae azygos are therefore represented by two venous trunks situated in the interior of the vertebral canal, where they receive the intercostal and lumbar veins, and finally communicate with the superior cava by means of a short single large trunk, which penetrates the parietes of the posterior and right side of the chest. The non-valvular structure of the veins in the Cetacea, and the pressure of the sea-water at the depths to which they retreat when harpooned, explain the profuse and deadly hemorrhage which follows a wound that in other mammalia would be by no means fatal.] t [My learned friend and colleague in the present work, Mr. T. Bell, considers the evidence to be strong, if not incontestable, in favour of the existence of a voice in the Cetacea. It is variously decribed as a bellow, a grunt, or a melancholy cry ; of which he cites several instances in his beautiful work on British quadrupeds, pp. 460, 475.] 368 HUNTER ON THE ANIMAL CECONOMY. long than in the piked whale seventeen feet, while the os hyoides was much larger. In the bottle-nose the os hyoides is composed of three bones, besides two whose ends are attached to it, being placed above the os hyoides, making five in all. In the porpoise, piked whale, &c, it is but one bone, slightly bent, having a broad thin process passing up, which is a little forked: it has no attachment to the head by means of other bones, as in many quadrupeds. The thyroid cartilage in the piked whale is broad from side to side, but not from the upper to the lower part: it has two lateral processes, which are long, and pass down the outside of the cricoid, near to its lower end, and are joined to it much as in the human subject. These differ in shape in different animals of this tribe. The cricoid cartilage is broad and flat, making the posterior and lateral part ofthe larynx, and is much deeper behind, and laterally, than before. It is extremely thick and strong, flattened on the posterior surface, and hollowed from the upper edge to the lower. It terminates by a thick edge on the posterior part above, but irregularly at the lower edge, in the cartilages ofthe larynx. The two arytenoid cartilages are extremely projecting, and united to each other till near their ends; are articulated on the upper edge of the cricoid, but send down a process, which passes on the inside of the cricoid, being attached to a bag in the piked whale, which is formed below the thyroid and before the cricoid cartilages ; they cross the cavity ofthe larynx obliquely, making the passage at the upper part a groove between them : the cavity at this place swells out laterally, but is very narrow between the anterior and posterior surfaces. The passage above between the arytenoid and thyroid cartilages is wide from side to side, and is continued down on the outside of the processes of the arytenoid cartilage, as well as between them, ending below the thyroid, which is folliculated on its inner surface on the fore part of the cricoid cartilage. The epiglottis makes a third part of the passage, and completes the glottis by forming it into a canal, in several of this tribe; but in the piked whale it was not attached to the two arytenoid cartilages, but only in contact, or inclosing them at their base, so as to make them form a complete canal. I could not observe anything like a thyroid gland.* From the glottis and epiglottis being so connected as to make but one canal, and from the thyroid and cricoid cartilages being so flattened in some between the anterior and posterior surface, the passage through these parts is very small or contracted ; but the trachea swells out again into a very considerable size. Its larger branches are in proportion to the trunk, and enter the lungs at the upper end along with the blood-vessels. * [This body certainly exists both in the porpoise and bottle-nose dolphin; it is bilobed, and placed transversely across the trachea. Below this body is the thymus, which extends into the chest and is much subdivided.] OBSERVATIONS ON THE STRUCTURE, ETC. 369 Ofthe Lungs.

The lungs are two oblong bodies, one on each side of the chest, and are not divided into smaller lobes, as in the humam subject. They are of considerable length, but not so deep between the fore and back part as in the quadruped, from the heart being broad, flat, and of itself filling up the fore part of the chest. They pass further down on the back part than in the quadruped, by which their size is increased, and rise higher up in the chest than the entrance of the vessels, coming to a point at the upper end. From the entrance of the vessels they are connected downwards, along their whole inner edge, by a strong attachment (in which there are in some lymphatic glands) to the posterior mediastinum. The lungs are extremely elastic in their substance, even so much so as to squeeze out any air that may be thrown into them, and to become almost at once a solid mass, having a good deal the appearance, consistence, and feel of an ox's spleen. The branches of the bronchias which ramify into the lungs have not the cartilages flat, but rather rounded; a construction which admits of greater motion between each.* The pulmonary cells are smaller than in quadrupeds, which may make less air necessary, and they communicate with each other, which those of the quadruped do not; for by blowing into one branch of the trachea, not only the part to which it immediately goes, but the whole lungs are filled. As the ribs in this tribe do not completely make the cavity of the thorax, the diaphragm has not the same attachments as in the quadruped, but is connected forwards to the abdominal muscles, which are very strong, being a mixture of muscular and tendinous fibres. The position of the diaphragm is less transverse than in the quadruped, passing more obliquely backwards, and coming very low on the spine, and higher up before; which makes the chest longest in the direction of the animal at the back, and gives room for the lungs to be continued along the spine. The parts immediately concerned in inspiration are extremely strong; the diaphragm remarkably so. The reason of this must at once appear; it necessarily requiring great force to expand in a dense medium like water, especially too when the vacuity is to be filled with one which is rarer, and is to water a species of vacuum, the pressure being much greater on the external surface than the counter-pressure from within. But expiration on the other hand must be much more easily performed ; the natural elasticity ofthe parts themselves, with the pressure of the water on the external surface of the body, being greater than the resistance ofthe air

* [The cartilaginous hoops of thebronchiae ar continued to their extreme ramifications. The pleura costalis is denser and stronger in the porpoise than serous membranes usually are.]

370 HUNTER ON THE ANIMAL CECONOMY.

within, will both tend to produce expiration without any immediate action of the muscles.* The diaphragm, in these animals, appears to be the principal agent in inspiration ; and the cavity of tbe thorax not being entirely surrounded by bony parts, is of course less easily expanded, and the apparatus for its expansion in all directions, as in the quadruped, does not exist here.

The Blow-hole, or Passage for the Air.

As the nose in every animal that breathes air is a common passage for the air, and is also the organ of smelling, I shall describe it in this tribe as instrumental to both these purposes. There is a variety in some species of this animal which is, I believe, peculiar to this order; that is, the want of the sense of smelling; none of those which I have yet examined having that sense, except the two kinds of whalebone whale : such of course have neither the'olfactory nerves, nor the organ ; therefore in them, the nostrils are intended merely for respiration ; but others have the organ placed in this passage as in other animals. The membranous portion of the posterior nostrils is one canal; but when in the bony part, in most of them, it is divided into two; the spermaceti whale, however, is an exception. In those which have it divided, it is in some continued double through the anterior soft parts, opening by two orifices, as in the piked whale; but in others, it unites again in the membranous part, making externally only one orifice, as in the porpoise, grampus, and bottle-nose. At its beginning in the fauces, it is a roundish hole, surrounded by a strong sphincter muscle, for grasping the epiglottis; beyond this, the canai becomes larger, and opens into the two passages in the bones of the head. This part is very glandular, being full of follicles, whose ducts ramify in the surrounding substance, which appears fatty and muscular like the root of the tongue, and these ramifications communicate with one another, and contain a viscid slime. In the spermaceti whale, which has a single canal, it is thrown a little to the left side. After these canals emerge from the bones near the external opening, they become irregular, and have several sulci passing out laterally, of irregular forms, with corresponding eminences. The structure of these eminences is muscular and fatty, but less muscular than the tongue of a quadruped. In the porpoise there are two sulci on each side; two large and two small, with corresponding eminences of different shapes, the large ones being thrown into folds. The spermaceti whale has the least of this structure; the external opening in it comes further forwards towards the anterior

* [Professor Mayer, of Bonn, has however recently described a muscular membrane as immediately investing the lungs in the dolphin.] OBSERVATIONS ON THE STRUCTURE, ETC. 371

part of the head, and is consequently longer than in others of this order. Near to its opening externally, it forms a large sulcus, and on each side of this canal is a cartilage, which runs nearly its whole length. In all that I have examined, this canal, forwards from the bones, is entirely lined with a thick cuticle of a dark colour. In those which have only one external opening, it is transverse, as in the porpoise, grampus, bottle-nose and spermaceti whale, &c.; where double, they are longitudinal, as in the piked whale, and the large whalebone whale. These openings form a passage for the air in respiration to and from the lungs : for it would be impossible for these animals to breathe air through the mouth; indeed, I believe the human species alone breathe by the mouth, and in them it is mostly from habit; for in quadrupeds the epiglottis conducts the air into the nose. In the whole of this tribe, the situation of the opening on the upper surface of the head is well adapted for this purpose, being the first part that comes to the surface of the water in the natural progressive motion of the animal ; therefore it is to be considered principally as a respiratory organ, and where it contains the organ of smell, that is only secondary. As the animals of this order do not live in the medium which they inspire, the organs conducting the air to the lungs are in some sort particularly constructed, that the water in which they live may not interfere with the air they breathe. The projecting glottis, which has been described, passes into the posterior nostrils, by which means it crosses the fauces, dividing them into two passages. The enlargement of the termination of the glottis, observed in some of them, would seem to be intended to prevent its retraction: but, as it seems confined to the porpoise and grampus, it may, perhaps, in them answer some other purpose. The beginning ofthe posterior nostrils, which answers to the palatum molle in the quadruped, having a sphincter, the glottis is grasped by it, which renders its situation still more secure, and the passages through the head, across the fauces and along the trachea, are rendered one continued canal; this union of glottis and epiglottis with the posterior nostril, making only a kind of joint, admits of motion, and of dilatation and contraction ofthe fauces, in deglutition, from the epiglottis moving more in or out of the posterior nostril. This construction of parts answers a purpose similar to that of the epiglottis in the quadruped; it may be considered as the epiglottis and the arytenoid cartilages joining to make a tubular or cylindrical epiglottis, instead of a valvular one. The reasons why there should be so peculiar a construction of parts do not at first appear; but we certainly see by it an absolute guard placed upon the lungs, that no water should get into them. This tribe being without the projecting tongue of the quadruped, and wanting its extensive motion and the power of sucking things into the mouth, may probably require the construction between the 372 HUNTER ON THE ANIMAL CECONOMY. air and lungs to be more perfect; but how far it is so I will not pretend to say. r

The Brain and Medulla Spinalis.

The size of the brain differs much in different genera of this tribe, and likewise in the proportion it bears to the bulk ofthe animal. In the porpoise, I believe, it is the largest, and perhaps in that respect comes nearest to the human. The size ofthe cerebellum in proportion to that of the cerebrum is smaller in the human subject than in any animal with which I am acquainted. In many quadrupeds, as the horse, cow, &c, the disproportion in size between cerebellum and cerebrum is not great and in this tribe it is still less ; yet not so small as in the bird, &c.' The whole brain in this tribe is compact, the anterior part ofthe cerebrum not projecting so far forwards as in either the quadruped or in the human subject; neither is the medulla oblongata so prominent, but flat, lying in a kind of hollow made by the two lobes of the cerebellum.* The brain is composed of cortical and medullary substances, very distinctly marked ; the cortical being in colour like the tubular substance of a kidney, the medullary very white. These substances are nearly in the same proportion as in the human brain. The two lateral ventricles are large, and in those that have olfactory nerves are not continued into them as in many quadrupeds ; nor do thev wind so much outwards as in the human subject, but pass close round the posterior ends of the thalami nervorum opticorum.f The thalami themselves are large, the corpora striata small;} the crura of the fornix are continued along the windings of the ventricles, much as in the human subject.^ The plexus choroides is attached to a strong membrane which covers the thalami nervorum opticorum, and passes through the whole course of the ventricle, much as in the human subject.||

* ['rLhe ^ost characteristic feature of the brain of the Cetacean is its great breadth, which exceeds its length. Each hemisphere is divided below by a fissura magna into an anterior and middle lobe, which extends over the cerebellum, so as to form a posterior lobe.] f [They extend, as in the human subject, into an anterior, descending and posterior horn : but the latter is very small.] ° X [The smallness of size of these parts, and the shortness ofthe anterior lobes of the brain are in relation with the absence of olfactory nerves. The corpora striata are brought into communication with each other by an anterior commissure.] § [The fornix sends down two slender anterior pillars to the corpora albicantia, and is continued into the anterior part of the corpus callosum; it then bends backwards along the under surface ofthe corpus callosum and above the thalami, and its posterior crura s.nk down, and diverge from each other to form the hippocampi.] || [The hemispheres of the brain are united by a corpus callosum, chiefly remarkable for its position, being much inclined downwards and forwards; its size is large, bearing the usual proportion to that of the hemispheres. The bigeminal bodies are large ; the anterior pair are rounded and lie close together; the OBSERVATIONS ON THE STRUCTURE, ETC. 373

The substance of the brain is more visibly fibrous than I ever saw it in any other animal, the fibres passing from the ventricles as from a centre to the circumference, which fibrous texture is also continued through the cortical substance. The whole brain in the piked whale weighed four pounds ten ounces.* The nerves going out from the brain, I believe, are similar to those ofthe quadruped, except in the want of the olfactory nerves in the genus of the porpoise. The medulla spinalis is much smaller in proportion to the size of the body than in the human species, but still bears some proportion to the quantity of brain; for in the porpoise, where the brain is largest, the medulla spinalis is largest; yet this did not hcfld good in the spermaceti whale, the size ofthe medulla spinalis appearing to be proportionally larger than the brain, which was small when compared to the size of the animal. It has a cortical part in the centre, and terminates about the twenty-fifth vertebra, beyond which is the cauda equina, the dura mater going no lower. The nerves which go off from the medulla spinalis are more uniform in size than in the quadruped, there being no such inequality of parts, nor any extremities to be supplied, except the fins.f The medulla spinalis is more fibrous in its structure than in other animals; and when an attempt is made to break it longitudinally it tears with a fibrous appearance, but transversely it breaks irregularly.} The dura mater lines the skull, and forms in some the three processes answerable to the divisions of the brain, as in the human subject; but in others this is bone. Where it covers the medulla spinalis it differs from all the quadrupeds I am acquainted with, inclosing the medulla closely, and the nerves immediately passing out through it at the lower part, as they do at the upper, so that the cauda equina, as it forms, is on the outside ofthe dura mater.

posterior are oval, and are separated by a depression which receives the anterior part ofthe vermiform process of the cerebellum. The medulla oblongata is characterized by the absence of the trapezoid bodies, in which respect it resembles that in the human subject and orang. The remarkable number and depth ofthe cerebral convolutions have been noticed by Tyson in the porpoise, by Scoresby in the whale, and by Tiedemann in the dolphin.] ♦ [Scoresby found the brain of the mysticete whale (Balxna Mysticetus) to weigh three pounds twelve ounces. Tyson found the brain of a porpoise, which weighed ninety-six pounds avoirdupoise, to weigh sixteen ounces and a half. I found the weight of the brain of an adult male porpoise to be one pound two ounces and three-quarters avoirdupoise.] t [The anterior roots of the spinal nerves are the largest: the posterior roots, after piercing the dura mater, are continued for a third of an inch before the ganglion is formed upon them, in the dorsal region; and the separate roots are progressively longer as they come off nearer the caudal extremity of the spinal chord. In the porpoise, from which the above deception is taken, I counted forty-one pairs of spinal nerves: the cervical are closely approximated in conse quence of the shortness of the neck.] X [The canal continued from the fourth ventricle is persistent in the anterior part ofthe spinal chord, as in the horse.] 33 374 HUNTER ON THE ANIMAL CECONOMY. The Organs of Sense.

As the organs of sense are variously formed in different animals, fitted for the various modes of impression ; and as the modes are either increased or varied, according to circumstances which make no part of the sense itself, but which are necessary for the ceconomy of the animal, we find the senses in this tribe varied in their construction, and in some a sense is even wholly wanting. The organs of sense which appear to be adapted to every mode of life are those of touch and taste; but those of smell, sight, and hearing, probably require to be varied according to circumstances. Thus smell may be increased by a mode of impregnation, hearing by the vibration of different mediums, and sight by the different powers of refraction of different mediums; therefore as animals are intended by Nature to be differently circumstanced, so are the senses formed.

The cutis in this tribe appears in general particularly well calculated for sensation, the whole surface being covered with villi, which are so many vessels, and we must suppose nerves. Whether this structure is only necessary for acute sensation, or whether it is necessary for common sensation, where the cuticle is thick and consisting of many layers, I do not know. We may observe that where it is necessary the sense of touch should be accurate the villi are usually thick and long, which probably is necessary, because in most parts ofthe body, where the more acute sensations of touch are required, such parts are covered by a thick cuticle. Of this the ends of our fingers, toes, and the foot of the hoofed animals, are remarkable examples. Whether this sense is more acute in water, I am not certain; but should imagine it is.

The tongue, which is the organ of taste, is also endowed with the sense of touch. It is likewise to be considered, in the greatest number of animals, as an instrument for mechanical purposes; but probably less so in this tribe than any other. However, even in these it must have been formed with this view, since merely as an organ of taste it would only have required surface, yet is a projecting body endowed with motion. In some it is better adapted for motion than in others ; and I should suppose this to be requisite, on account of the difference in the mode of catching the food and in the act of swallowing. It is most projecting in those with teeth, probably for the better conducting the food, step by step, to the oesophagus; whereas it does not seem so necessary to have such management of the tongue in those which have no teeth, and OBSERVATIONS ON THE STRUCTURE, ETC. 375

catch their food by merely opening the mouth and swimming upon it, or by having their prey carried in by the water. In the porpoise and grampus it is firm in texture, composed of muscle and fat, being pointed and serrated on its edges, like that of the hog.* In the spermaceti whale the tongue was almost like a featherbed.t In the piked whale it was but gently raised, hardly having any lateral edges, and its tip projecting but little, yet, like every other tongue, composed of muscle and fat. The extent between the two jaw-bones in this whale was very considerable, taking in the whole width of the head or upper jaw, and of course including the whalebone. This extent of surface between jaw and jaw, having but little projection of tongue, is almost flat from side to side, is extremely elastic when contracted, and throws the inner membrane into a vast number of very small folds, that run parallel to one another, but which are again thrown into a close serpentine course by the elasticity of the part in a contrary direction. From the tongue being capable of but little motion, there is only a small mass of muscle required; and, from the thinness of the jaw-bone, the distance between the lower surface of the mouth and external surface of the skin is but small; and this skin being ribbed and very elastic is capable of considerable distention, by which the cavity of the mouth can be enlarged. The tongue of the large whalebone whale, I should suppose, rose in the mouth considerably; the two jaws at the middle being kept at such a distance on account of the whalebone, so that the space between, when the mouth is shut, must be filled up by the tongue.

Of the Sense of Smelling. In this tribe of animals there is something very remarkable in what relates to the sense of smelling; nor have I been able to discover the particular mode by which it is performed. When we consider these animals as mammalia, and only constructed differently in external form for progressive motion through water, we must see that it was necessary that all the senses should correspond with this medium: we must therefore be at a loss to conceive how they smell, since we may observe that the organ for smelling water, as in fish, is very different from that formed to smell air; and as we must suppose this tribe are only to smell water, being the medium in which such odoriferous particles can be diffused, we should expect their organ to be similar to that of fish; but in that case nature would have been obliged to have attacked the nose of a fish to an animal constructed like a quadruped; and

* [We have found the marginal serration of the tongue of the hog only in the fcetus or very young state.] .... A, ., , , , t [It is, howeverrof much smaller size m this species than in the whalebone whales.] 376 H ENTER ON THE ANIMAL CECONOMY.

it is contrary to the laws which are established in the animal creation to mix parts of different animals together. In many of this tribe there is no organ of smell at all; and in those which have such an organ, it is not that of a fish, therefore probably not calculated to smell water. It becomes difficult therefore to account for the manner in which such animals smell the water; and why the others should not have had such an organ,* which, I believe, is peculiar to the large and small whalebone whales. Although it is not the external air which they inspire that produces smell, I believe it is the air retained in the nostril out of the current of respiration, which by being impregnated with the odoriferous particles contained in the water during the act of blowing, is applied to the organ of smell. It might be supposed that they could smell the air on the surface of the water by every inspiration, as animals do on land ; and probably they may : but this will not give them the power to smell the odoriferous particles of their prey in the water at any depth; and as their organ is not fitted to be affected by the application of water, and as they cannot suck water into the nostril without the danger of its passing into the lungs, it cannot be by its application to this organ that they are enabled to smell. Some have the power of throwing the water from the mouth through the nostril, and with such force as to raise it thirty feet high : this must answer some important purpose, although not immediately evident to us. As the organ appears to be formed to smell air only, and as I conceive the smelling of the external air could not be of use as a sense, I therefore believe that they do not smell in inspiration ; yet let us consider how they may be supposed to smell the odoriferous particles of the water. The organ of smell is out of the direct road of the current of air in inspiration ; it is also out of the current of water when they spout; may we not suppose then, that this sinus contains air, and as the water passes in the act of throwing it out, that it impregnates this reservoir of air, which immediately affects the sense of smell? This operation is probably performed in the time of expiration, because it is said that this water is sometimes very offensive; but all this I only give as conjecture. If the above solution is just, then only those which have the organ of smell can spout, a fact worthy of inquiry. The organ of smell would appear to be less necessary in these animals than in those which live in air, since some are wholly deprived of it; and the organ in those which have it is extremely

* Is the mode of smelling in fish similar to tasting in other animals? Or is the air contained in the water impregnated with the odoriferous parts, and this air the fish smells ] If so, it is somewhat similar to the breathing of fish, it not being the water which produces the effect there, but the air contained in it. This I proved by experiments, and is mentioned by Dr. Priestly. OBSERVATIONS ON THE STRUCTURE, ETC. 377 small, when compared with that of other animals, as well as the nerve which is to receive the impression, as was observed above.*

The ear is constructed much upon the same principle as in the quadruped ; but as it differs in several respects, which it is necessary to particularize, to convey a perfect idea of it the whole should be described. As this would exceed the limits of this paper, I shall content myself with a general description, taking notice of those material points in which it differs from that of the quadruped. This organ consists of the same parts as in the quadruped ; an external opening, with a membrana tympani, an Eustachian tube, a tympanum with its processes, and the small bones.f There is no external projection forming a funnel, but merely an external opening. We can easily assign a reason why there should be no projecting ear, as it would interfere with progressive motion; but the reason why it is not formed as in birds, is not so evident; whether the percussions of water could be collected into one point as air, I cannot say. The tympanum is constructed with irregularities, so much like those of an external ear, that I could suppose it to have a similar effect. The external opening begins by a small hole, scarcely percepti-

* [It is singular that Mr. Hunter should not have added a description of the organ, the function of which is the subject of so many singular and original speculations in the preceding section. The olfactory nerve in the whalebone whale (Balxna Mysticetus) is solid, as in the human subject, but round, about half an inch in diameter at its narrowest part, and gradually swelling into a pyriform bulbous termination, from the fundus of which the divisions of the nerve pass off through the foramina of the cribriform plate; the larger of these foramina are from one to two lines in diameter, about twenty in number, and placed chiefly around the circumference ofthe cribriform plate; there are two large ones in the centre which lead to the root of the middle spongy bone. The lamella itself is concave towards the fossa of the nerve. The nerves are lodged for some distance in a peculiar cavity, surrounded by the cancellous diploe of the skull, leading from the cranial cavity to the cribriform plate. The turbinated bones are three in number, but are none of them distinct, merely projections from the side of the nasal cavity into its area. The middle one is the largest; besides its lateral adhesion, it is attached by a narrow pedicle to the cribriform plate, from which it quickly expands into a body of about one and a half inch in diameter, having an upper, middle, and lower protuberance separated by sinuosities; but the bone is not a convoluted plate, but solid, or having its substance of the same cellular structure as the surrounding diploe. The inferior turbinated process is a simple elliptic protuberance, about one inch in length and half an inch in width. The olfactory nerves in the Balxnoptera axe somewhat larger than in the human subject; they are of a pulpy texture, yet readily divisible into fasciculi, and terminate in a small bulb which rests on the cribriform plate. Treviranus states that olfactory nerves, but of very minute size do, exist in the porpoise; and V. Baer describes them as being one-sixth of a line in diameter in the Delphinus Delphis.] | [The internal ear or labyrinth, which Hunter afterwards describes as ' the immediate organ,' seems to have been accidentally omitted in the above enumeration.] 33* 378 HUNTER ON THE ANIMAL CECONOMY. ble, situated on the side of head a little behind the eye.* It is much longer than in other animals, in consequence of the size of the head being so much increased beyond the cavity that contains the brain. It passes in a serpentine course, at first horizontally, then downwards, and afterwards horizontally again, to the membrana tympani, where it terminates. In its whole length it is composed of different cartilages, which are irregular and united together by cellular membrane, so as to admit of motion and probably of lengthening or shortening, as the animal is more or less fat. The bony part of the organ is not so much inclosed in the bones of the skull as in the quadruped, consisting commonly of a distinct bone or bones, closely attached to the skull, but in general readily to be separated from it ;f yet. in some it sends off, from the posterior part, processes which unite with the skull. It varies in its shape, and is composed of the immediate organ and the tympanum. The immediate organ is, in point of situation to that of the tympanum, superior and internal, as in the quadruped, The tympanum is open at the anterior end, where the Eustachian tube begins. The Eustachian tube opens on the outside of the upper part of the fauces: in some higher in the nose than others; highest I believe in the porpoise. From the cavity of the tympanum where it is rather largest, it passes forwards and inwards, and near its termination appears very much fasciculated, as if glandular.J The Eustachian tube and tympanum communicate with several sinuses, which, passing in various directions, surround the bone of the ear. Some of these are cellular, similar to the cells of the mastoid process in the human subject, although not bony. There is a portion of this cellular structure of a particular kind, being white, ligamentous, and each part rather rounded than having flat sidcs.§

* [In the full-grown spermaceti whale Mr. F. D. Bennett found the aperture ofthe meatus auditorius to form a narrow longitudinal fissure, one inch in length; it admitted with difficulty the extremity ofthe index finger.] f [Being united to the skull by fibrous texture only, a structure which is peculiar to the Cetacea, but not universal in that order.] X [The Eustachian tube in the true Cetacea is characterized by its membranous structure throughout; its parietes are nowhere supported by cartilage, nordoesit traverse any bone. In the porpesse its internal surface is provided with many semilunar valves, the free margins of which are directed towards the nasal outlet of the tube.] § These communications with the Eustachian tube may be compared to a large bag on the bases of the skull of the horse and ass, which is a lateral swell of the membranous part of the tube, and when distended will contain nearly a quart.* a [In a beautiful drawing of the organ of hearing in the porpoise, recently published by the College of Surgeons, Hunter gives a view of part of the sinuses which communicate with the tympanum and Eustachian tube. See Physiological Catalogue ofthe Hunterian Collection, vol. iii., pi. xxxiv. i. k. In the preparation (No. 1582) the sinuses are seen to contain numerous small worms (Strongylus minor), Kuhn, Mem. du Museum, torn, xviii., p. 363. The same have been observed by other physiologists, as Klein, Camper, Albers, and Rudolphi, the latter of whom regards them as a small variety of the Strongylus infiexus,] OBSERVATIONS ON THE STRUCTURE, ETC. 379

One of the sinuses passing out of the tympanum close to the membrana tympani, goes a little way in the same direction, and communicates with a number of cells. The whole function of the Eustachian tube is perhaps not known ; but it is evidently a duct from the cavity of the ear, or a passage for the mucus of these parts; the external opening having a particular form would incline us to believe, that something was conveyed to the tympanum. The bony part ofthe organ is very hard and brittle, rendering it even difficult to be cut with a saw without itschipping into pieces. That part which contains the immediate organ is by much the hardest, and has a very small portion of animal substance in it; for when steeped in an acid, what remains is very soft, almost like a jelly, and laminated. The bone is not only harder in its substance but there is on the whole more solid bone than in the corresponding parts of quadrupeds, it being thick and massy. The part containing the tympanum is a thin bone, coiled upon itself, attached by one end to the portion which contains the organ ; and this attachment in some is by close contact only, as in the narwhale ; in others, the bones run into one another, as in the bottlenose and piked whales. The concave side of the tympanum is turned towards the organ, its two edges being close to it; the outer is irregular, and in many only in contact, as in the porpoise : while in others the union is by bony continuity, as in the bottle-nose whale, leaving a passage on which the membrana tympani is stretched, and another opening, which is the communication with the sinuses. The surface ofthe bone containing the immediate organ opposite to the mouth of the tympanum is very irregular, having a number of eminences and cavities. The cavity of the tympanum is lined with a membrane, which also covers the small bones with their muscles, and appears to have a thin cuticle. This membrane renders the bones, muscles, tendons, &c, very obscure, which are seen distinctly when that is removed. It appears to be a continuation ofthe periosteum, and the only uniting substance between the small bones. Besides the general lining, there is a plexus of vessels, which is thin and rather broad, and attached by one edge, the rest being loose in the cavity of the tympanum, somewhat like the plexus choroides in the ventricles of the brain. The cavity we may suppose intended to increase sound, probably by the vibration of the bone; and from its particular formation we can easily conceive, that the vibrations are conducted, or reflected, towards the immediate organ, it being in some degree a substitute for the external ear. The external opening being smaller lhan in any animals ofthe same size, the membrana tympani is nearly in the same proportion. In the bottle-noso whale, the grampus, and porpoise, it is smooth and concave externally, but of a particular construction on the inner surface ; for a tendinous process passes from it towards the malleus, 380 HUNTER ON THE ANIMAL CECONOMY.

converging as it proceeds from the membrane, and becoming thinner till its insertion into that bone. I could not discover whether it had any muscular fibres which could affect the action of the malleus. In the piked whale, the termination ofthe external opening, instead of being smooth and concave, is projecting, and returns back into the meatus for above an inch in length,* is firm in texture, with thick coats, is hollow on its inside, and its mouth communicating w7ith the tympanum ; one side being fixed to the malleus, similar to the tendinous process which goes from the inside ofthe membrana tympani in the others.f A little way within the membrana tympani, are placed the small bones, which are three in number, as in the quadruped, malleus, incus, and stapes; but in the bottle-nose whale there is a fourth, placed on the tendon of the stapedius muscle. These bones are as it were suspended between the bone of the tympanum and that of the immediate organ. The malleus has two attachments, besides that with the incus; one close to tho bone of the tympanum, which, in the porpoise, is only by contact, but in others by a bony union ;J the other attachment is formed by the tendon, above described, being united to the inner surface of the membrana tympani. Its base articulates with the incus.

* [As might be expected, the same structure exists in the whalebone whale (Balxna Mysticetus, Linn.), where, according to Home, the membrana tympani " instead of being concave, as in other animals, towards the meatus externus, is convex and projects nearly an inch into that tube." Phil. Trans. 1812, p. 84. In this respect, the whalebone whales resemble the sloths, the turtle, and crocodile, and in fact the whole series of air-breathing oviparous vertebrata, which have the ear-drum convex externally. In the dolphins and porpoises, however, as also in the narwhale, the membrana tympani is concave externally, as in other Mammalia.] f [This connexion between the membrana tympani and the malleus is denied by Sir Everard Home, who wrote a paper and gave two plates in support of his opinion. After quoting Mr. Hunter's description, he says, " the fact is, that there is no connection whatever between the membrana tympani and the malleus;" and adds, that " this circumstance forms the great peculiarity in the organ of hearing in this species of whale (Balxna Mysticetus, Linn.)." So singular an anomaly as the absence of any communication between the membrana tympani and the ossicula auditus, would, independently of our interest in the character of Hunter as an accurate observer, have induced us to spare no pains to test the conflicting statements with the facts themselves. It fortunately happens that the preparations figured by Home are preserved (No. 1598 a. Physiological Series, Hunterian Museum) ; and after a careful examination of them, we find the following to be the true structure ofthe parts in question. The membrane marked c in Home's figure (Phil. Trans., 1812, pi. II.) is continuous at d with e, the convex projection of the membrana tympani; whereas, the edge of the shadow is so strong in the figure as to cause it to appear as if c and e were separate membranes, as Home describes them to be: they are, however, parts of the same membrana tympani, the attachment of which is extended inwards beyond the circumference of the termination of the bony meatus auditorius. The triangular ligament proceeding from the handle of the malleus, and which is common to all the Cetacea, is attached not only to the plane portion of the ear-drum, but to the whole of one side of the convex portion which projects into the meatus, and is affected by every motion of that portion.] X [The malleus is anchylosed to the parietes of the tympanum in the dugong.] OBSERVATIONS ON THE STRUCTURE, ETC.. 381

The incus is attached by a small process to the tympanum, and is suspended between the malleus and stapes. The process by which it articulates with the stapes is bent towards that bone. The stapes stands on the vestibulum, by a broad oval base. In many of this tribe, the opening from side to side of the stapes is so small as hardly to give the idea of a stirrup." The muscles which move these bones are two in number, and tolerably strong. One arises from that projecting part of the tympanum which goes to form the Eustachian tube, and running backwards is inserted into a small depression on the anterior part of the malleus. The use of this muscle seems to be to tighten the membrana tympani; but in those which have the malleus anchylosed with the tympanum, we can hardly conjecture its use. The other has its origin from the inner surface of the tympanum, and passing backwards is inserted into the stapes by a tendon, in which I found a bone in the large bottle-nose. This muscle gives the stapes a lateral motion. What particular use in hearing may be produced by the action of these muscles, I will not pretend to .say ; but we must suppose, whatever motion is given to the bones must terminate in the movement ofthe stapes. The immediate organ of hearing is contained in a round bony process, and consists ofthe cochlea and semicircular canals, which somewhat resemble the quadruped; but, besides the twro spiral turns of the cochlea^there is a third, which makes a ridge within that continued from the foramen rotundum, and follows the turns ofthe canal. The cochlea is much larger, when compared with the semicircular canals, than in the human species and quadruped. We may reckon two passages into the immediate organ of hearing, the foramen rotundum, and foramen ovale. They are at a greater distance than in the quadruped. The foramen rotundum is placed much more on the outer surface of the bone, and not in the cavity of the bony tympanum ; but may be said to communicate with the surrounding cellular part of the tympanum. The foramen rotundum, which is the beginning of one of these turns (the scala cochleae, which is the central or inner canal), appears to be only one end of a transverse groove, which is afterwards closed in the middle, forming a canal with the two ends open; so that this foramen appears to have two beginnings; but the other opening is probably only a passage for blood-vessels going to the cochlea. From this foramen begins the inner turn ofthe cochlea, which is the largest, especially at its beginning; the other begins from the vestibulum. The cochlea is a spiral canal coiled within itself, and divided into two by a thin spiral bony plate, which is completed in the recent subject, and forms two perfect canals. In the recent subject, the foramen rotundum is lined with the

* [In the Delphinus Leucas, the stapes is imperforate, as in the walrus.] 382 HUNTER ON THE ANIMAL CECONOMY. membrane of the tympanum, which terminates in a blind end, forming a kind of membrana cochleas. The other opening, in the recent subject, communicates with the spiral turn, beyond the membranous termination of the foramen rotundum. The foramen ovale has a little projection inwards all around, on which the stapes stands: within this is the vestibulum, which is common to the other spiral turn of the cochleas, and the semicircular canals; this canal of the cochlea (scala vestibuli) passes out first in a direction contrary to its general course, but soon makes a turn into the spiral. It is round, and not merely a division ofthe cochlea into two by a septum,* but has a membrane of its own, which is attached to the thin bony plate, and lines that part ofthe cochlea in such a manner as to retain its structure when the bone is removed. The cochlea in some completes one turn and a half; in others, more.f It is not a spiral on a plane, or cylinder, but on a cone. I have already observed, that by looking in at the foramen rotundum, we see two small ridges; the uppermost is the swell of the canal from the vestibulum just described ; the lower ridge, which is also a canal, may be observed just to pass along the foramen belonging to this canal, close to the septum between the two; a circumstance, I believe, peculiar to this tribe. Its beginning is close to the vestibulum, but does not open from it, and passes along the first-described spiral turn to its apex: when opened, it appears to be a canal full of small perforations, probably the passages ofthe branches from the auditory nerve. This bony process has several perforations in it; one of them large, for the passage of the seventh pair of nerves. The size of the portio mollis, before its entrance into the organ, is very large,! and bears no proportion to that which enters. The passage for this nerve is very wide, and seems to have an irregular blind conical, and somewhat spiral, termination ; its being spiral arise from the closeness to the point of the cochlea. In the terminating part there are a number of perforations into the cochlea, and one into the semicircular canals,§ which afford a passage to the different divisions of the auditory nerve. There is a considerable foramen in its anterior side near the bottom, for the passage of the portio dura, and which is continued backward to the cavity ofthe tympanum near the stapes, and emerges near the posterior and upper part of this bone.

* [i. e., It is a cylindrical canal, not semicylindrical as usual in quadrupeds.] * f [In the porpesse, the number of gyrations are two and a half. Rudolphi describes two and a half gyrations in the narwhale. Rapp describes two complete gyrations in the Delphinus Delphis, and Pallas the same number in the Delph. Leucas.] X [Tiedemann particularly notices the large size of the acoustic nerve in the dolphin.] § [The semicircular canals are chiefly remarkable for their small proportional size; they were overlooked by Camper and Pallas, but were described by Comparetti two years later than Hunter, in his " Observations anatomicse de Anreinterna," Patavii, 1789.] OBSERVATIONS ON THE STRUCTURE, ETC. 383

The eye in this tribe of animals is constructed upon nearly the same principle as that of quadrupeds, differing, however, in some circumstances; by which it is probably better adapted to see in the medium through which the light is to pass. It is upon the whole small for the size of the animal,* which would lead to the supposition that their locomotion is not great; for I believe animals that swim are in this respect similar to those that fly; and as this tribe come to the surface of the medium in which they live, they may be considered in the same view with birds which soar; and we find birds that fly to great heights, and move through a considerable space in search of food, have their eyes larger in proportion to their size. The eyelids have but little motion,f and do not consist of loose cellular membrane, as in quadrupeds, but rather of the common adipose membrane of the body; the connection, however, of their circumference with the common integuments is loose, the cellular membrane being less loaded with oil, which allows of a slight fold being made upon the surrounding parts in opening the eyelids. This is not to an equal degree in them all, being less so in the porpoise than in the piked whale. The tunica conjunctiva, where it is reflected from the eyelid to the eyeball, is perforated all round by small orifices of the ducts of a circle of glandular bodies lying behind if. The lachrymal gland is small ;J its use being supplied by those above mentioned; and the secretion from them all I believe to be a mucus similar to what is found in the turtle and crocodile. There are neither puncta nor lachrymal duct, so that the secretion, whatever it may be, is washed off into the water. The muscles which open the eyelids are very strong: they take their origin from the head, round the optic nerve, which in some requires their being very long, and are so broad as almost to make one circular muscle round the whole of the interior straight muscles of the eye itself. They may be divided into four; a superior, an inferior, and one at each angle : as they pass outwards to the eyelids, they diverge and become broader, and are inserted into the inside of the eyelids almost equally all round. They may be termed the dilatores of the eyelids; and, before they reach their insertion,give

* [The longest diameter ofthe eye ofthe mysticete whale and ofthe cachalot ►is two.inches and a half, that of the piked whale four inches; but the eye owes much of its bulk to the thick sclerotic. An affinity to the elephant and other large Pachyderms is manifested in this circumstance.] t [The true Cetacea have no tarsel cartilages, and no membrana nictitans, or third eyelid ; this is present in the harbivorous species, as the dugong and manatee, and is represented by a thick duplicature of the conjunctiva at the inner canthus in the cachalot.] X [This is merely a larger development of the palpebral glands at the inner side ofthe eyeball, and should therefore be regarded as analogous to a Harderian gland.] 384 HUNTER ON THE ANIMAL CECONOMY. off the external straight muscles, which are small,* and inserted info the sclerotic coat before the transverse axis of the eye: those maybe named the elevator, depressor, adductor, and abductor, and maybe dissected away from the others as distinct muscles. Besides these four going from the muscles of the eyelid to the eye itself, there are two which are larger, and inclose the optic nerve with the plexus. As these^ pass outwards they become broad, may in some be divided into four, and are inserted into the sclerotic coat, almost all round the eye, rather behind its transverse axis.f The two oblique muscles are very long; they pass through the muscles of the eyelids, are continued on to the globe of the eye, between the two sets of straight muscles, and at their insertions are very broad; a circumstance which gives great variation to the motion of the eye.J The sclerotic coat gives shape to the eye, both externally and internally, as in other animals; but the external shape and that of the internal cavity are very dissimilar, arising from the great difference in the thickness of this coat in different parts. The external figure is round, except that it is a little flattened forwards; but that of the cavity is far otherwise, being made up of sections of various circles, being a little lengthened from the inner side to the outer, a transverse section making a short ellipsis. In the piked whale the long axis is two inches and three-quarters, the short axis two inches and one-eighth.§ The posterior part of the cavity is a tolerably regular curve, answering to the difference in the two axises; but forwards, near the cornea, the scleretic coat turns quickly in, to meet the cornea,

*[The word "small" is here used relatively to the palpebral muscles; for, compared with the size ofthe eyeball the recti muscles in the Cetacea exceed in bulk those of any other mammiferous animal.] t [These shorter series of straight muscles correspond with thechoanoid muscle or retractor ocuh of other mammalia in which (man and the quadrumana excepted), it coexists with a membrana nictitans, and is subservient to its motions by retracting the globe of the eye and displacing the adipose matter posterior to the eyeball, which then presses forward the third eyelid. In the true Cetacea where there is no third eyelid some other uses must be assigned for the retractor ocuh; it may perhaps assist by retracting the eyeball, in°closing the ordinary eyelids, which have not the advantage of an orbicularis muscle for that purpose. The retractor oculi is represented by four short muscles in the turtle and tortoise, where the third eyelid is present, but has a special muscle for nictitation.] r ± [The superior oblique arises, as in other mammalia, from the posterior part of the orbit above the foramen opticum ; it passes forwards on the external surface of the conical apertor palpebrarum, which it perforates, and a kind of pulley is formed for it by this muscle and the cellular substance beneath it, the superior oblique becoming at this bend partially tendinous, but with little diminution of size ; it then goes to be inserted into the sclerotica, at such a direction to the ball of the eye as to act as a rotator to it, according to the use assigned by Hunter to the oblique muscles in a previous memoir. The inferior oblique arises from the superior maxillary bone at the inner side ofthe orbital space. Neither the direction of this or of the superior oblique in the whales enables them to act as the antagonists ofthe recti muscles.]

.1 §a C?n M'T °f lhe ,SeCtT °.f the e?e of a whale in Soemering's work, entitled, " De Oculorum sectwne honzontali, tab. ii.] OBSERVATIONS ON THE STRUCTURE, ETC. 385

which makes this part of the cavity extremely flat, and renders the distance between the anterior part of the sclerotic coat and the bottom of the eye not above an inch and a quarter. In the piked whale the sclerotic coat, at its posterior part, is very thick: near the extreme of the short axis it was half an inch, and at the long axis one-eighth of an inch thick. In the bottle-nose whale (Hyperoodon) the extreme of the short axis was half an inch thick, and the extremes of the long axis about a quarter of an inch, or half the other. The sclerotic coat becomes thinner as it approaches to its union with the cornea, where it is thin and soft. It is extremely firm in its texture where thick, and from a transverse section would seem to be composed of tendinous fibres, intermixed with something like cartilage: in this section four passages for vessels remain open. This firmness of texture precludes all effect of the straight muscles on the globe of the eye, by altering its shape, and adapting its focus to different distances of objects, as has been supposed to be the case in the human eye. The cornea makes rather a longer ellipsis than the ball ofthe eye ; the sides of which are not equally curved, the upper being most considerably so. It is a segment of a circle somewhat smaller than that of the eyeball, is soft and very flaccid.* The tunica choroides resembles that of the quadruped ; and its inner surface is of a silver hue, without any nigrum pigmentum.f The nigrum pigmentum only covers the ciliary processes, and lines the inside of the iris.J

* [In the preparation No. 1682, Physiological Series, Hunterian Museum, Hunter has displayed the laminated structure of the cornea of the whale ; this was known to Leeuenhoek, who succeeded in separating it into twenty-two layers. See Epist. Phys. p. 42, which are united by a fine cellular tissue.] f [The choroid in the cetacea is easily sepaj-able into two vascular laminae, of which the outermost is of a blackish colour, and is composed of larger vessels, connected by cellular membrane, which gives it a tomentose appearance; the innermost (membrana rhuischiana) is equally vascular, of a pale colour, dense, but thinner, most delicately villous and lined by a remarkable tapetum of a bluishwhite colour in the whale, with a greenish and somewhat yellowish tinge in the cachalot, and of a very light blue in the porpesse. The ciliary zone is black, broad, almost flat, composed of about seventy long processes, thick, flexous, and extending their cylindrical apices almost as far as the anterior surface of the lens.] X [When this layer of pigment is removed from the iris, (as Hunter has done in the preparation 1680, Physiological Series,) the fibrous structure of the posterior part ofthe iris becomes very apparent; the outer series of fibres converge towards the margin ofthe pupil, where they are concealed by the sphincterfibres which surround that part; these latter elliptically disposed fibres are stronger than the radiated ones. The posterior fibrous coat of the iris may be separated without much difficulty from the anterior vascular layer. This consists chiefly of the branches of the two long ciliary arteries, which bifurcate opposite the long axis of the pupil, and, the opposite branches anastomosing, form a canal which surrounds the pupil. Numerous tortuous or wavy branches radiate from this canal towards the outer margin of the iris. In the preparations No. 1680 and 1683 the structure of the iris in the whale is beautifully shown. The choroid is puckered up into numerous minute folds, which form the ciliary 34 3S6 HUNTER ON THE ANIMAL CECONOMY. The retina appears to be nearly similar to that of the quadruped. The arteries going to the coats of the eye form a plexus passing round the optic nerve, resembling in its appearance that of the spermatic artery in the bull and some other animals.* The crystalline humour resembles that of the quadruped; but whether it is very convex or flattened I cannot determine, those I have examined having been kept too long to preserve their exact shape and size.-f The vitreous humour adhered to the retina at the entrance of the optic nerve. The optic nerve is very long in some species, owing to the vast width of the head. J I shall not at present consider the eye in animals of this tribe, as it respects the power of vision, that being performed on a general principle common to every animal inhabiting the water; more especially as I am only master of the construction and formation of the coats, and not of the size, shape, and densities of the humours; yet from reasoning we must suppose them to correspond with the shape of the eye, and the medium through which the light is to pass. Of ihe Parts of Generation.

The parts of generation in both sexes of this order of animals come nearer in form to those of the ruminating than of any others, and this similarity is, perhaps, more remarkable in the female than in the male, for their situation in the male must vary on account of external form, as was before observed. The testicles retain the situation in which they were formed, as in those quadrupeds in which they never come down into the scrotum.§ They are situated near the lower part of the abdomen, one on each side, upon the two great depressors of the tail. At this part of the abdomen the testicles come in contact with the abdominal muscles anteriorly.|| zone; of these folds every third, fourth, or fifth becomes enlarged, and is extended forwards in the form of a wrinkled process about three lines in length, compressed laterally, and terminating somewhat obtusely; between these larger ciliary processes, which are about seventy in number, there are shorter processes of a similar structure.] * [See prep. No. 1679, Physiological Series, Hunterian Museum.] t [The crystalline lens is inclosed in a strong capsule, is remarkably globose, rather more flattened anteriorly than posteriorly, placed at a very small distance from the cornea, and accordingly diminishing the space for the aqueous, while it increases that for the vitreous humour. In the preparations of the crystalline lens in the Hunterian Museum, preps. Nos. 1658-1687, the nucleus is seen to be excentric, and situated on the posterior half of the lens, and is of a dark colour.] X [When this nerve is divided transversely, and the medullary substance squeezed out, the neurilema does not present the form of tubes, but of numerous septa, which converge from the circumference to the centre of the nerve.] § [In this respect however the cetacea differ from the ruminants, and resemble the elephant and the hyrax amongst the pachyderms.] || [At the period of sexual excitement the testes acquire a great size. In a male porpoise I found them occupying almost entirely the posterior fourth part of OBSERVATIONS ON THE STRUCTURE, ETC. 387

The vasa deferentia pass directly from the epididymis behind the bladder, or between it and the rectum, into the urethra ; and there are no bags similar to those called vesiculae seminales in certain other animals.* The structure of the penis is nearly the same in them all, and formed much upon the principle of the quadruped. It is made up of two crura, uniting into one corpus cavernosum, and the corpus spongiosum seems first to enter the corpus cavernosum. In the porpoise, at least, the urethra is found nearly in the centre of the corpus cavernosum; but towards the glans seems to separate or emerge from it, and becoming a distinct spongy body, runs along its under surface, as in quadrupeds. The corpus cavernosum in some is broader from the upper part to the lower than from side to side; but in the porpoise has the appearance of being round, becoming smaller forwards, so as to terminate almost in a point some distance from the end of the penis.f The glans does not spread out as in many quadrupeds, but seems to be merely a plexus of veins covering the anterior end of the penis, yet is extended a good way further on, and is in some no more than one vein deep. The crura penis are attached to two bones, which are nearly in the same situation and in the same part of the pelvis as those to which the penis is attached in quadrupeds ; but these bones are only for the insertion of the crura, and not for the support of any other part, like the pelvis in those animals which have posterior extremities, neither do they meet at the fore part, or join the vertebras of the back.J the abdominal cavity ; they measured each nine inches in length and four inches in the shortest diameter, and weighed together four pounds avoirdupois. The corpus Highmorianum occupied the middle or axis of the gland, as in all testes which are subject to considerable enlargement at the period of the rut; and the membranous septa radiate from this body to the tunica albuginea.] * [The epididymis in the porpoise is of an elongated triedral form; the broadest facet is connected by a duplicature of peritonaeum to the testes; the connexion is close, except at the lower part of the gland, where the membrane is half an inch broad. The vas deferens continues to be convoluted, as in other testiconda, to within two inehes of its termination in the dilated bulbous part ofthe urethra : the lining membrane ofthe terminal two inches of the vas deferens is denser, and of a less glandular structure than the preceding part.] t [The corpus cavernosum is remarkable for the thickness of its fibrous sheath, which equals that of the contained erectile tissue; the fibres composing the sheath affect distinctly two directions, the external ones running longitudinally, the internal circularly.] t [These bones are of an elongated form, and are regarded by Cuvier as analogous to the iliac bones; but as they give attachment to the crura penis, and as the erectores penis arise from their whole outer and posterior surfaces, they would seem to be rather the homologues of the ischia. A strong tendon is continued, in the porpoise, from the anterior and internal extremity of each bone, descends obliquely inwards, and after the course of an inch and a half expands into a muscular belly, which joins its fellow in the mesial line behind the rectum. Below this fleshy belly on each side there is an oval, flattened, slightly concave bone. The commencement of the urethra is surrounded by thick capsule of muscular fibres, which arise from the inner and anterior part of the ischia, and from the 3S8 HUNTER ON THE ANIMAL CECONOMY. The erectores penis are very strong muscles, having an origin and insertion similar to those ofthe human subject. The acceleratores muscles are likewise very strong; and there is a strong and long muscle, arising from the anus, and passing forwards to the bulb of the penis, that runs along the under surface of the urethra, and is at last lost or inserted in the corpus spongiosum. This muscle draws the penis into the prepuce, and throws that part of the penis that is behind its insertion into a serpentine form. It is common to most animals that draw back the penis into what is called the sheath, and may be called the retractor penis. In all the females which I have examined, the parts of generation are very uniformly the same, consisting of the external opening, the vagina, the uterus, fallopian tubes, fimbrias, and ovaria. The external opening is a longitudinal slit, or oblong opening, whose edges meet in two opposite points, and the sides are rounded off, so as to form a kind of sulcus. The skin and parts on each side of this sulcus are of a looser texture than on the common surface ofthe animal, not being loaded with oil, and allowing of such motion of one part on another, as admits of dilatation and contraction. The vagina passes upwards and backwards towards the loins, so that its direction is diagonal respecting the cavity of the abdomen, and then divides into the two horns, one on each side of the loins; these afterwards terminating in the fallopian tubes, to which the ovaria are attached. From each ovarium there is a small fold ofthe peritonaeum, which passes up towards the kidney of the same side, as in most quadrupeds. The inside of the vagina is smooth for about one-half of its length, and then begins to form something similar to valves projecting towards the mouth of the vagina, each like an os tineas; these are about six, seven, eight, or nine in number. Where they begin to form, they hardly go quite round, but the last arc complete circles. At this part too the vagina becomes smaller, and gradually decreases in width to its termination.* From the last projecting part, the passage is continued up to the opening of the two horns, and the inner surface of this last part is thrown into longitudinal rugae, which are continued into the horns. Whether this last partis to be reckoned common uterus or vagina, and that the last valvular part is to be considered as os tineas, I do not know ; but from its having the longitudinal rugae, I am inclined to think it is uterus, this structure appearing to be intended for distinction.!

inner surface of the oval bones above mentioned. These fibres seem, therefore, to correspond with Wilson's muscle combined with the muscular part of the urethra. They envelope a glandular substance analogous to a prostate.] * [A muscle arises, on each side, from the whole length ofthe ischial bone, and passing inwards is inserted into the external surface of the vagina, and into the crura of the clitoris. This body is situated like a projecting ridge, without any preputial fold, between the thin labise. On each side of the clitoris within the mouth of the vagina, are the orifices of sinuses, analogous to the canals of Malpighi in Ruminantia.] f [From the os tineas, which Hunter calls the last projecting part of the vagina, OBSERVATIONS ON THE STRUCTURE, ETC. 389

The horns are an equal division of this part; they make a gentle turn outwards, and are of considerable length. Their inner surface is thrown into longitudinal rugas, without any small protuberances for the cotyledons to form upon, as in those of ruminating animals ;* and where they terminate, the fallopian tubes begin. In the bottle-nose whale (Hyperoodon), where the fallopian tubes opened in the horns of the uterus, they were surrounded by pendulous bodies hanging loose in the horns. The fallopian tubes, at their termination in the uterus, are remarkably small for some inches, and then begin to dilate rather suddenly; and the nearer to the mouth the more this dilatation increases, like the mouth of a French horn, the termination of which is five or six inches in diameter.f They are very full of longitudinal rugae through their whole length. The ovaria are oblong bodies about five inches in length, one end attached to the mouth of the fallopian tube, and the other near to the horn of the uterus.J They are irregular on their external surface, resembling a capsula renalis or pancreas. They have no capsula, but what is formed by the long fallopian tube. How the male and female copulate, I do not know; but it is alleged that their position in the water is erect at that time, which I ca°n readily suppose may be true ; for otherwise, if the connection is long, it would interfere with the act of respiration, as in any other position the upper surface of the heads of both could not be at the surface of the water at the same time. However, as in the parts of generation they most resemble those of the ruminating kind, it is possible they may likewise resemble them in the duration ofthe act of copulation; for, I believe, all the ruminants are quick in this act. Of their uterine gestation I as yet know nothing; but it is very probable that they have only a single young one at a time, there being only two nipples.^ This seemed to be the case with the botto the beginning ofthe division ofthe uterus, in the porpoise, is about two inches. The uterus is lined with a very smooth mucous membrane; a thin layer of cellular substance separates this from the muscular tunic, in which the circular fibres may be clearly discerned. The external tunic is derived from the peritoneum which forms the broad ligaments.] * [The foetus has neither placenta nor colytodons, but, as in the hog and camel, the general vascularity of the chorion is subservient to its nutrition and respiration, The allantois is coextensive in its development with the chorion, and both extend into the horns of the uterus.] t [The margin of this opening, in the porpoise, is entire, without fimbriated processes.] t [In the porpesse the ovaria are attached to the ovarian ligament, and are situated half way between the expanded orifice of the fallopian tube and the extremity ofthe uterine horn.] § [The dolphin has generally one, but sometimes two at a birth, according to Aristotle. According to Pallas, the Beluga (Delphinus Leucas) brings forth two, but the exception to The general rule may have been observed in this case; since Fabricius describes the same species as being uniparous(Fauna Grcenlandica, p. 51). The Greenland whale brings forth a single young one in April. The spermaceti whale produces one voung one every year, according to Mr. Beale (Obs. on the 34* 300 HUNTER ON THE ANIMAL CECONOMY. tle-nose whale caught near Berkeley, which had been seen for some days with one young one following it, and they were both caught together. The glands for the secretion of milk are two, one on each side ofthe middle line of the belly at its lower part. The posterior ends, from which go out the nipples, are on each side ofthe opening of the vagina, in small sulci. They are flat bodies lying between the external layer of fat and abdominal muscles, and are of considerable length, but only one-fourth of that in breadth. They are thin, that they may not vary the external shape of the animal, and have a principal duct, running in the middle through the whole length of the gland, and collecting the smaller lateral ducts, which are made up of those still smaller. Some of these lateral branches enter the common trunk in the direction of the milk's passage-, others in the contrary direction, especially those nearest to the termination of the trunk in the nipple. The trunk is large, and appears to serve as a reservoir for the milk,¥ and terminates externally in a projection, which is the nipple. The lateral portions of the sulcus which incloses the nipple are composed of parts looser in texture than the common adipose membrane, which is probably to admit of the elongation or projection of the nipple. On the outside of this there is another small fissure, which, I imagine, is likewise intended to give greater facility to the movements of all these parts. The milk is probably very rich ; for in that caught near Berkeley with its young one, the milk which was tasted by Mr. Jenner and Mr. Ludlow, surgeon, at Sodbury, was rich, like cow's milk to which cream had been added. The mode in which these animals must suck would appear to be very inconvenient for respiration, as either the mother or young one will be prevented from breathing at the time, their nostrils being in opposite directions; therefore the nose of one must be under water, and the time of sucking can only be between each respiration. The act of sucking must likewise be different from that of land animals; as in them it is performed by the lungs drawing the air from the mouth backwards into themselves, which the fluid follows, by being forced into the mouth from the pressure of the external air on its surface ; but in this tribe, the lungs having no connection with the mouth, sucking must be performed by

Sperm. Whale, 8vo., p. 36). Mr. F. D. Bennett found in a gravid cachalot a single fcetus fourteen feet in length, and 6ix in girth; its position in the uterus was that of a bent bow. (Zool. Proceed., Dec. 1836.) When brought forth the young cachalot is usually twenty feet in length. And we may observe that the cetacer. in general are remarkable for the large sizoof the fcetus at birth. Camper describes the new-born porpoise as being half the size of the parent. (Obs. Anatomiques sur les Cetaces, p. 147.) The rudimental condition of the pelvis renders the birth easy.] * [From this reservoir the milk is injected into the mouth of the young by the action of powerful cutaneous muscles, arranged so as to compress the reservoir and dilated ducts ofthe mammary glands.] ON THE ANATOMY OF THE JERBOA. 391

some action of the mouth itself, and by its having the power of expansion.* NOTES ON THE ANATOMY OF THE JERBOA, (Dipus Sagitta, Gm.) (Extracted from the Appendix to Russel's History of Aleppo, where they are thus introduced.)

"Having met with nothing more on the internal structure of the jerboa than what is given by Gmelin from M. Buffon (Hist. Nat. torn, xiii.), I applied to my worthy friend Mr. John Hunter, who very obligingly favoured me with the following circumstances from his Adversaria by way of supplement. He was not certain whether the animal he dissected was from Asia or Africa." ....The meatus auditorius was large like that of a bird. The tympanum was also large, f There are two venae cavae superiores. The cascum was four inches in length; it makes a close turn upon itself, and gradually diminishing in size, terminates in an obtuse point. The colon, which is large at its beginning, passes first upwards upon the right side, and before crossing the abdomen on the left, makes a little fold upon itself; it then crosses the spine, and making another fold shorter than the former, it passes the left side and commences rectum. The lower part of the abdomen lies upon the anterior part of the pubes, and the bend of the penis is seen within the cavity of the abdomen, making a little projection, as it were, between the origin ofthe two musculi recti. The penis in a flaccid state lies reverted upon itself, but when in erection has a bone on each side of the part projecting, in the same manner as in the guinea-pig. The prepuce is furnished with a number of glands which secrete a thick mucus. The testicles are situated on each side of the symphysis, and can occasionally lie in the rings of the abdominal muscles, which are very large, but can never descend much further, there being no scrotum for their reception. The vesiculae seminales are two long bags, which make a turn upon themselves. The anus is bent downwards towards the parts of generation.!

* [Aided, as in the Marsupiata and Monoiremata, by muscular actions on the part ofthe parent tending to expel the milk.] t [See the Preparation No. 1599 Physiological Series, Hunter Museum, which is most probably the part here described, and if so, proves the description to be of the Dipus Sagitta.] X [These short and simple notes are interesting as an example of the matter composing the lost " Adversaria," or manuscript notes of Hunter. The comparison which he makes with reference to the structure of the ear-passage shows that he was alive to those interesting points of structure which are indicative of the natural affinities of different groups of animals. The jerboa not only resembles the bird in the large size of the meatus auditorius, but also (together with the 392 HUNTER ON THE ANIMAL CECONOMY. 35. ANATOMICAL DESCRIPTION OF THE AMPHIBIOUS BIPES OF ELLIS, (Siren Lacertina, Linn.)

The tongue is broad and has very little motion. It has a bone similar to that in birds, turtles, &c. On the posterior and lateral

whole order of Rodentia) in the unanchylosed state of the tympanum with the other elements of the temporal bone. In the affinity to the oviparous vertebrata manifested in the two superior cavee, the genus Dipus agrees with the following rodent genera : Alactaga, Helamys, Echimys, Hystrix, Sciurus, Pteromys, Orycteropus, Bathyergus, Lepus, and Ccelogenys. I have also shown that the same structure characterizes the marsupial animals. See Proceedings ofthe Zoological Society, April 1832.] * [This paper was read before the Royal Society June 5, 1766, and is interesting from the circumstance of its being the first which Hunter communicated to that learned body, as well as from its being the earliest contribution to the anatomy of one ofthe most singular tribes of animals at present in existence, viz. the Batrachiaperennibranchiata, or true Amphibia. The sirens dissected by Hunter were brought from South Carolina in 1758, and purchased along wilh other subjects of natural history by Mr. Hunter; the specimens described by Ellis were transmitted to him by Dr. Alexander Gardner, of Charles Town, South Carolina. The natives call the siren "mudiguana." It is found in swampy and muddy places by the sides of pools, under the trunks of old trees that hang over the water. The external description ofthe siren by Mr. Ellis is given in the explanation of the plate Iii., p. 23. Besides the siren, Mr. Hunter also obtained two other species of perennibranchiate reptiles, dissections of which are preserved in his museum, and recorded in his manuscripts under the names of " Kuttewagoe" (the Menopoma Alleghanniensis of Dr. Harlan) and the "Amphibious quadruped," since particularly described by Cuvier under the name of " Amphiuma.'' The types of three other genera of perennibranchiata have subsequently been described, and the whole tribe is divided into those which retain the external branchiae throughout life, and those which lose these vascular processes, but retain the gill apertures. The sirens and menobranchus of the United States, ihe axolotl of Mexico, and the proteus of Hungary have external fimbriated branchiae, while the amphiuma and menopoma have only the branchial arches and apertures, but not external gills. These genera are all perfectly distinct from each other both in their external and anatomical characters, and it is only with respect to one of them, viz. the axolotl, that any doubt still remains as to whether the gills are permanent or not. At the period ofthe discovery of the siren it was natural to suppose from the analogy of the newt and salamander that it was a larva, representing an immature stage of its existence, on which subject LinnjEus thus cautiously expresses himself in a letter to Mr. Ellis. " Upsal, December 27, 1765. I received Dr. Garden's very rare two-footed animal with gills and lungs. The animal is probably the larva of some kind of Lacerta, which I very much desire that he will particularly inquire into. " If it does not undergo a change, it belongs to the order of Nantes, which have both lungs and gills ; and if so, it must be a new and very distinct genus, and should most probably have the name of Siren. "I cannot possibly describe to you how much this two-footed animal has exercised my thoughts; if it is a larva he will no doubt find some of them with four feet. It is not an easy matter to reconcile it to the larva ofthe lizard tribe, its ANATOMICAL DESCRIPTION, ETC. 393 parts of the mouth are three openings on each side; these are similar to the slits of the gills in fish, but the partitions do not resemble gills on their outer edges, for they have not the comb-like structure. Above* and close to the extremity of each of these openings externally, so many processes arise, the anterior the smallest, the posterior the largest; their anterior and inferior edges and extremity are serrated, or formed into fimbrias; these processes fold down and cover the slits externally, and would seem to answer the purposes of the comb-like part of the gill in fish. At the root of the tongue, nearly as far back as these openings reach, the trachea begins much in the same manner as in birds. It passes backwards above the heart, and there divides into two branches, one going to each lobe of the lungs. The lungs are two long bags, one on each side, which begin just behind the heart, and pass back through the whole length of the abdomen, nearly as far as the anus. They are largest in the middle, and honey-combed on the internal surface through their whole length. The heart consists of one auricle and one ventricle. What answers to the inferior vena cava passes forwards above, but in a sulcus of the liver, and opens into a bag similar to the pericardium; this bag

fingers being furnished with claws; all the larvas of lizards that I know are without them (" digitis muticis"). Then also the branchiae or gills are not to be met with in the aquatic salamanders, which are probably the larvas of lizards. Further, the croaking noise or sound it makes does not agree with the larvas of these animals, nor does the situation of the anus. So that there is no creature that ever I saw that I long so much to be convinced ofthe truth as to what this will certainly turn out to be." Dr. Pockells of Brunswick, who visited the Museum of the Royal College of Surgeons, in 1820, perceiving some specimens of Amphiuma, concluded from their having 'four legs and no external gills that they were the adult or perfect Siren, and Rusconi adopted this opinion without further investigation ; but Cuvier has shown that the Amphiuma differs from the Siren in its osteological structure, having in one species ten, and in another twenty-two additional vertebrae, while the construction of the cranium and other parts of the skeleton are totally different: moreover the completely ossified state of the skeleton of the Siren, without the slightest vestige of" posterior extremities, proves it to be neither the larva of an Amphiuma or of any other known Amphibian. See Rusconi, Descr. Anat. delle larve Salamandre, 4to., 1817; Del Proteo Anguino, 4to., 1819; and Amours des Salamandres, fol. 1826, p. 12. Cuvier, Reckerches sur les Reptiles douteux, in Humboldt's Obs. Zool., 4to., 1811-1827 ; Ossemens Fossiles, tom. v. pt. 2 : Mem. du Mus., tom. xiv. See also " A Notice of a Siren Lacertina,'''' kept alive at Canon Mills, Edinburgh, for more than six years, in Jamieson's Journal, 1832, p. 298. From the observations made on this animal it appears that the branchiae are the respiratory organs most essential to its existence, and its death is supposed to have been occasioned by the fimbriae of the gills becoming completely dried and shrivelled up, in consequence of its accidentally falling out of the box of water in which it was habitually kept. It ate worms, sticklebacks, and small minnows greedily ; and showed great alertness and sagacity in concealing itself most accurately beneath afloatincr patch of frog-bit. ° * To avoid the confusion in our ideas which might arise from the use of the words anterior, posterior, upper, lower, &c, in the whole of this description the animal is considered in its natural horizontal position, so that the head is forwards, the back upwards, &c. 394 HUNTER ON THE ANIMAL CECONOMY. surrounds the heart and aorta, as the pericardium does in other animals; from this there is an opening into a vein which lies above, and upon the left of the auricle, which vein seems to receive the blood from the lungs, gills, and head, is analogous to the superior vena cava, and opens into the auricle, which is upon the left of the ventricle. The aorta goes out, passing for a little way in a loose spiral turn, then becomes straight, where it seems to be muscular; at this part the branches go off, between which there is a rising within the area of the aorta like a bird's tongue, with its tip turned towards the heart.* The liver is principally one lobe, pretty close to the heart at the fore part, and passes back on the right of the stomach and intestines; at its anterior extremity on the left side there is a very short lobe, ending abruptly. The gallbladder lies in a fissure on the left side of the liver near its middle; these is no hepatic duct; the hepato-cystic ducts, which seem to be three in number, enter the gall-bladder at its anterior end or fundus, and the cystic duct passes out from the posterior end ofthe gallbladder, and terminates in the gut, about half an inch from the pylorus. The oesophagus which is pretty large, passes back, and is continued into the stomach in the same line. The stomach at the posterior end bends a little to the right, where it terminates in the pylorus. The intestines pass back, making many turns ; at the posterior end they become pretty straight, forming what may be called the colon, or rectum, where they are a little larger, and run to the anus in a straight direction. At the beginning of this larger part ofthe intestinal tube there is no valvular structure. The spleen

* This account of the venae cavas opening into the cavity of the pericardium may appear incredible ; and it might be supposed that, in the natural state ofthe parts, there is a canal of communication going from one cava to the other, which being broken or nipped through, in the act of catching or killing the animal, would give the appearance above described. I can only say that the appearances were what have been described in three different subjects which I have dissected; and in all of them the pericardium was full of coagulated blood. But besides the smallness ofthe subjects, it may be observed that they had been long preserved in spirits, which made them more unfit for anatomical inquiries. They had been in my possession above seven years.1 a [There is no preparation in the Hunterian Collection demonstrative of the structure described in the text, and it was in the dissection of the siren, instituted with the view to reconcile or account for Hunter's description of the heart, that I was led to the discovery of the two distinct auricles in that animal. (Trans. Zool. Soc, vol. i., p. 213, April, 1834.) The inferior vena cava terminates at the lower part of a large membranous sinus, which also receives the blood from the two superior cavae by two separate orifices. The common trunk of the pulmonary veins seems also to end in this sinus, but it merely traverses without communicating with it, and finally opens into a distinct transverse auricular chamber, which is not separated externally from the apparently single and capacious auricle of the venae cavae, which is characterized by numerous elongated fimbriated processes. The glistening fibrous coat of the pericardium closely adheres to the surrounding muscles as in fish, so that the absence of any detached bag surrounding the heart, the magnitude ofthe auricle, and the peculiar passage ofthe pulmonary veins through the great sinus ofthe venae cavae may have contributed to mislead Mr. Hunter as to the real structure ofthe part.] OF THE ELECTRIC PROPERTY OF THE TORPEDO. 395

is a very small but long body; its anterior end is attached to the upper surface of the stomach, and it is continued back along the left side of the mesentery, to which it adheres. The pancreas is a small body lying above the duodenum, and is attached also to the mesentery. The kidneys are situated in the upper and posterior part ofthe abdomen, having the rectum passing below and between them, as in the snake, &c. Below the rectum lies a long bag, like a bladder; it adheres all along to the inside of the abdominal muscles, and its mouth opens into the rectum; but whether it is the bladder of urine or not I cannot tell. On each side of the rectum, close to the lungs, there is a body, the posterior end of which rests upon the anterior end of the kidney ; whether they are testicles or ovaria I cannot pretend to determine, but should imagine that they are either the one or the other.* 36. OF THE ELECTRIC PROPERTY OF THE TORPEDO.

In a Letter from John Walsh, Esq., F.R.S., to Benjamin Franklin, Esq., L.L.D. F.R.S., Ac. R. Par. Soc. Ext., &c.f

Chesterfield Street, July 1,1773. Dear Sir, I am concerned that other engagements have prevented me from giving to the Royal Society, before their recess, a complete account of my experiments on the electricity of the torpedo; a subject not only curious in itself, but opening a large field for interesting inquiry, both to the electrician in his walk of physics, and to all who consider, particularly or generally, the animal ceconomy. To supply the deficiency in the best manner I am now able, I will request the favour of you to lay before the Society my letter

* [The ovaria in the siren are irregularly shaped elongated somewhat compressed bodies, becoming smaller at the two extremities. In a siren of two feet long they were each four inches in length, and half an inch broad, both situated at the lower and back part of the abdomen: the left about an inch nearer the head, having a smooth surface outwardly, and moulded on the inner surface to the convolutions ofthe intestine. The stroma ovarii was crowded with very numerous and minute ovisacs of a whitish colour, and was studded here and there with larger drops of a dark-coloured oil. The oviducts extend from the cloaca, in the form of broad, flattened, membranous canals, to near the anterior ends of the ovaria, where they alter their form and become rounded tubes, each becoming folded upon itself in broad close-set plaits, and terminating, without change of dimensions, in a longitudinal slit, which occupies part of the anterior surface of the last plait. The oviducts are attached by a broad fold of peritoneum to the dorsal region of the abdomen.] t [This letter is prefixed to Mr. Hunter's description of the Electric Organs, in the Philosophical Transactions, vol. lxiii.] 39G HUNTER ON THE ANIMAL CECONOMY.

from La Rochelle, ofthe 12th July, 1772, and such part of the letter I afterwards wrote from Paris as relates to this subject. Loose and imperfect as these informations are, for they were never intended for the public eye, they are still the most authentic, and so far the most satisfactory I can at present offer, since the notes I made ofthe experiments themselves remain nearly, I am sorry to say it, in that crude and bulky state in which you had the trouble to read them.

Letter from Mr. Walsh to Dr. Franklin, dated La Rochelle, July 12, 1772.

" It is with particular satisfaction I make to you my first communication, that the efiect of the torpedo appears to be absolutely electrical; by forming its circuit through the same conductors wifh electricity, for instance, metals and water; and by being intercepted by the same non-conductors, for instance, glass and sealingwax. I will not at present trouble you with the detail of our experiments, especially as we are daily advancing in them, but only observe that we have discovered the back and breast of the animal to be in different states of electricity; I mean in particular the upper and lower surfaces of those two assemblages of pliant cylinders of which you have seen engravings in Lorenzini.* By the knowledge of this circumstance we have been able to direct his shocks, though they were very small, through a circuit of four persons, all feeling them; likewise through a considerable length of wire held by two insulated persons, one touching his lower surface, and the other his upper. When the wire was exchanged for glass or sealing wax no effect could be obtained, but as soon as it was resumed the two persons became liable to the shock. These experiments have been varied many ways and repeated times without number, and they all determined the choice of conductors to be the same in the torpedo as in the Leyden phial. The sensations likewise occasioned by one and the other in the human frame are precisely similar. Not only the shock, but the numbing sensation which the animal sometimes dispenses, expressed in French by the words engourdissement and fourmillement, may be exactly imitated with the phial, by means of Lane's electrometer, the regulating rod of which, to produce the latter effect, must be brought almost into contact with the prime conductor which joins the phial. We have not yet perceived any spark to accompany the shock, nor the pith balls to be ever affected.*!

* Observazioni intorno alle Torpedini di Stef. Lorenzini, 1678. Redi appears to be the first who remarked these singular parts of the torpedo in 1666. Franc. Redi, Exper. Nat. f [Gardini and Galvani, and more recently Matteuci, concur in stating that they have seen a feeble spark from the discharge of a torpedo, but other philosophers have not been so successful. The observations of Dr. John Davy on this point (Philos. Tran3., 1834) particularly deserve attention. He experimented on very active fish, and varied his trials, with every endeavour to obtain the re- OF THE ELECTRIC PROPERTY OF THE TORPEDO. 397

Indeed, all our trials have been done on very feeble subjects, whose shock was seldom sensible beyond the touching finger. I remember but one, of at least two hundred that I myself must have received, to have extended above the elbow. Perhaps the Isle of Re, which we are about to visit, may furnish us with torpedos fresher taken and of more vigour, by which a further insight into these matters may be had. Our experiments have been chiefly in the air, where the animal was more open to our examination than in water. It is a singularity that the torpedo, when insulated, should be able to give to us, insulated likewise, forty or fifty successive shocks from nearly the same part, and these with little, if any, diminution in their force; indeed, they were all very minute. Each effort in the animal to give the shock is conveniently accompanied with a depression of his eyes, by which even his attempts to give it to non-conductors can be observed. The animal, with respect to the rest of his body, is in a great degree motionless, but not wholly so. You will please to acquaint Dr. Bancroft of our having thus verified his suspicion concerning the torpedo,* and make any other communication of this matter you may judge proper. Here I shall be glad to excite, as far as I am able, both electricians and naturalists to push their inquiries concerning this extraordinary animal, whilst the summer affords them the opportunity." Extracts of a Letter from Mr. Walsh to Dr. Franklin, dated Paris August 27, 1772.

'.......I spent a complete week in my experiments at the Isle of Re, and had there every convenience for prosecuting them to their extent, except that I was restrained by the jealousy of the government from making them where the animal was caught. At my return to La Rochelle, I communicated to the members of the Academy of that place and to many of the principal inhabitants all that I had observed concerning the torpedo, in the intention of

quired result, but never procured a spark. By means of Harris's electrometer, however, he saw proof of the evolution of heat during the torpedo's discharge. Abundant evidence of the chemical effects of animal electricity has been obtained by the same philosopher. He applied golden wires, one to the dorsal, the other to the ventral surface ofthe torpedo, and passed the discharge through solutions of nitrate of silver, common salt, and superacetate of lead, and found that all were decomposed, but the latter substance only when the fish seemed to put forth all its energy, after being much irritated (Philos. Tran3., 1832). In resuming the inquiry instituted by Sir Humphry Davy, relative to the magnetical effects of the torpedo's discharge, Dr. John Davy ascertains in the most satisfactory manner that these effects were produced by animal electricity. He placed eight needles within a spiral of fine copper wire, containing about one hundred and eighty convolutions, and having passed through this a single discharge from a torpedo six inches long, the contained needles were all converted into magnets, and the ends of the needles which were nearest the ventral surface of the fish had received the southern polarity. See Phil. Trans., 1829.] * Bancroft's Natural History of Guiana, p. 194. 35 398 HUNTER ON THE ANIMAL CECONOMY. stirring up a spirit of inquiry both as to its electricity and general ceconomy. "......The vigour of the fresh-taken torpedos at the Isle of Re was not able to force the torpedinal fluid across the minutest tract of air; not from one link of a small chain, suspended freely to another; not through an almost invisible separation, made by the edge of a penknife, in a slip of tinfoil pasted on sealing-wax. The spark, therefore (of course the attendant snapping noise), was denied to all our attempts to discover it, not only in daylight, but in complete darkness. I observed to you in my last the singularity of the torpedo being able, when insulated, to give to an insulated person a great number of successive shocks: in this situation I have taken no less than fifty from him in the space of a minute and a half. All our experiments confirmed that his electricity was condensed in the instant of its explosion by a sudden energy of the animal, and as there was no gradual accumulation nor retention of it, as in the case of charged glass, it is not at all surprising that no signs of attraction nor repulsion were perceived in the pith balls. In short, the effect of the torpedo appears to arise from a compressed elastic fluid, restoring itself to its equilibrium in the same way and by the same mediums as the elastic fluid compressed in charged glass. The skin of the animal, bad conductor as it is, seems to be a better conductor of his electricity than the thinnest plate of elastic air. Notwithstanding the weak spring of the torpedinal electricity, I was able, in the public exhibitions of my experiments at La Rochelle, to convey it through a circuit, formed from one surface ofthe animal to the other, by two long brass wires and four persons, which number at times was increased even to eight. The several persons were made to communicate with each other, and the two outermost with the wires, by means of water contained in basins, properly disposed between them for the purpose, each person dipping his hands in the nearest basins, connectively with his neighbour on either side....... " The effect produced by the torpedo when in air appeared, on many repeated experiments, to be about four times as strong as when in water." A clear and succinct narrative of what passed at one of the public exhibitions alluded to in the last letter appeared in the French Gazette of the 30th October, 1772. As it came from a very respectable quarter, not less so from the private character of the gentleman than from the public offices he held, I must desire leave of the Society to avail himself of such a testimony to the facts 1 have advanced by giving a translation of that narrative.

Extract of a Letter from the Sieur Seignette, Mayor of La Rochelle, and Second Perpetual Secretary of the Academy ^of that City, to the publisher ofthe French Gazette.

" In the Gazette of the 14th August, you mentioned the discovery made by Mr. Walsh, member of the parliament of England, and of OF THE ELECTRIC PROPERTY OF THE TORPEDO. 399

the Royal Society of London. The experiment of which I am going to give you an account, was made in the presence of the Academy of this city. A live torpedo was placed on a table. Round another table stood five persons insulated. Two brass wires, each thirteen feet long, were suspended to the ceiling by silken strings. One of these wires rested by one end on the wet napkin on which the fish lay ; the other end was immersed in a basin full of water placed on the second table, on which stood four others basins likewise full of water. The first person put a finger of one hand in the basin in which the wire was immersed, and a finger of the other hand in the second basin. The second person put a finger of one hand in this last basin, and a finger of the other hand in the third; and so on successively, till the five persons communicated with one another by the water in the basins. In the last basin one end ofthe second wire was immersed ; and with the other end Mr. Walsh touched the back of the torpedo, when the five persons felt a commotion which differed in nothing from that of the Leyden experiment, except in the degree of force. Mr. Walsh, who was not in the circle of conduction, received no shock. This experiment was repeated several times, even with eight persons, and always with the same success. The action of the torpedo is communicated by the same mediums as that ofthe electric fluid. The bodies which intercept the action of the one, intercept likewise the action ofthe other. The effect produced by the torpedo resemble in every respect a weak electricity. " This exhibition of the electric powers of the torpedo before the Academy of La Rochelle, was at a meeting held for the purpose in my apartments, on the 22d July, 1772, and stands registered in the journals ofthe Academy. The effect of the animal was, in these experiments, transmitted through as great an extent and variety of conductors as almost at any time we had been able to obtain it, and the experiments included nearly all the points in which its analogy with the effect of the Leyden phial had been observed. These points were stated to the gentlemen present, as were the circumstances in which the two effects appeared to vary. It was likewise represented to them, that our experiments had been almost wholly with the animal in the air; that its action in water was a capital desideratum; that indeed all as yet done was little more than opening the door to inquiry ; that much remained to be examined by the electrician as well as by the anatomist; that as artificial electricity had thrown light on the natural operation of the torpedo, this might in return, if well considered, throw light on artificial electricity, particularly in those respects in which they now seemed to differ ; that for me, I was about to take leave of the animal, as nature had denied it to the British seas ; and that the prosecution of these researches rested in a particular manner with them, whose shores abounded with it. The torpedo on this occasion dispensed only the distinct, instantaneous stroke so well known by the name of the electric shock. 400 HUNTER ON THE ANIMAL CECONOMY. That protracted but lighter sensation, that torpor or numbness which he at times induces, and from which he takes his name, was not then experienced from the animal; but it was imitated with artificial electricity, and shown to be producible by a quick consecution of minute shocks. This in the torpedo may perhaps be effected by the successive discharge of his numerous cylinders, in the nature of a running fire of musketry : the strong single shock may be his general volley. In the continued effect, as well as in the instantaneous, his eyes, usually prominent, are withdrawn into their sockets. The same experiments, performed with the same torpedos, were on the two succeeding days repeated before numerous companies of the principal inhabitants of La Rochelle. Besides the pleasure of gratifying the curiosity of such as entertained any on the subject, and the desire I had to excite a prosecution of the inquiry, I certainly wished to give all possible notoriety to facts, which might otherwise be deemed improbable, perhaps by some of the first rank in science. Great authorities had given a sanction to other solutions ofthe phasnomena of the torpedo; and even the electrician might not readily listen to assertions, which seemed in some respects to combat the general principles of electricity. I had reason to make such conclusions from different conversations I had held on the subject with eminent persons both at London and Paris. It is but justice to say, that of all in that class you gave me the greatest encouragement to look for success in this research, and even assisted me in forming hypotheses, how the torpedo, supposed to be endued with electric properties, might use them in so conducting an element as water. After generally recommending to others an examination of the electric powers of these animals when acting in water, I determined, before I took my final leave of them, to make some further experiments myself with that particular view; since, notwithstanding the familiarity in which we may be said to have live with them for near a month, we had never detected them in the immediate exercise of their electric faculties against other fish, confined with them in the same water, either in the circumstance of attacking their prey, or defending themselves from annoyance; and yet that they possessed such a power, and exercised it in a state of liberty, could not be doubted. A large torpedo, very liberal of his shocks, being held with both hands by his electric organs above and below, was briskly plunged into water to the depth of a foot, and instantly raised an equal height into air; and was thus continually plunged and raised, as quick as possible, for the space of a minute. In the instant his lower surface touched the water in his descent, he always gave a violent shock, and another still more violent in the instant of quitting the water in his ascent; both which shocks, but particularly the last, were accompanied with a writhing in his body, as if meant to force an escape: besides these two shocks from the surface of the water, OF THE ELECTRIC PROPERTY OF THE TORPEDO. 401

which may yet be considered as delivered in the air, he constantly gave at least two when wholly in the air, and constantly one, and sometimes two, when wholly in the water. The shocks in the water appeared, as far as sensation could decide, not to have near a fourth of the force of those at the surface of the water, nor much more than a fourth of those entirely in the air. The shocks received in a certain time were not on this occasion counted by a watch, as they had been on a former, when fifty were delivered in a minute and a half by the animal in an insulated and unagitated state : but from the quickness with which the immersions were made, it may be presumed there were full twenty of these in a minute; from whence the number of shocks in that time must . have amounted to above a hundred. This experiment, therefore, while it discovered the comparative force between a shock in water and one in air, and between a shock delivered with greater exertion on the part of the animal and one with less, seemed to determine, that the charge of his organs with electricity was effected in an instant, as well as the discharge. The torpedo was then put into a flat basket, open at top, but secured by a net with wide meshes, and in this confinement was let down into the water about a foot below the surface : being there touched through the meshes with only a single finger on one of his electric organs, while the other hand was held at a distance in the water, he gave shocks which were distinctly felt in both hands. The circuit for the passage of the effect being contracted to the finger and thumb of one hand, applied above and below to a single organ produced a shock, to our sensation, of twice the force of that in the larger circuit by the arms. The torpedo, still confined in the basket, being raised to within three inches of the surface of the water, was there touched with a short iron bolt, which was held half above and half in the water by one hand, while the other hand was dipped as before at a distance in the water; and strong shocks, felt in both hands, were thus obtained through the iron. A wet hempen cord being fastened to the iron bolt, was held in the hand above water, while the bolt touched the torpedo; and shocks were obtained through both those substances. A less powerful torpedo, suspended in a small net, being frequently dipped into water and raised again, gave from the surface of the water slight shocks through the net to the person holding it. These experiments in water manifested that bodies immersed in that element might be affected by immediate contact with the torpedo ; that the shorter the circuit in which the electricity moved, the greater would be the effect; and that the shock was communicable from the animal in water to persons in air through some substances. How far harpoons and nets, consisting of wood and hemp, could in like circumstances, as it has been frequently asserted, convey the effect, was not so particularly tried as to enable us to confirm 35* 402 HUNTER ON THE ANIMAL CECONOMY.

it. I mention the omission in the hope that some one may be induced to determine the point by express trial. We convinced ourselves on former occasions that the accurate Kasmpfer,* who so well describes the effect of the torpedo, and happily compares it with lightning, was deceived in the circumstance that it could be avoided by holding in the breath, which we found no more to prevent the shock of the torpedo when he was disposed to give it, than it would prevent the shock of the Leyden phial. Several persons, foaming as many distinct circuits, can be affected by one stroke of the animal, as well as when joined in a single circuit. For instance, four persons, touching separately his upper and lower surfaces, were all affected ; two persons likewise, after the electricity had passed through a wire into a basin of water, transmitted it from thence, in two distinct channels, as their sensation convinced them, into another basin of water, from whence it was conducted, probably in a united state, by a single wire. How much further the effect might be thus divided and subdivided into different channels was not determined ; but it was found to be proportionably weakened by multiplying these circuits, as it had been by extending the single circuit. Something may be expected to be said of the parts of the animal immediately concerned in producing the electrical effect. The engraving which accompanies this letter, while it shows the general figure ofthe torpedo, gives an internal view of his electric organs. The Society will, besides, have a full anatomical description of these parts from the ingenious Mr. John Hunter, in a paper he has expressly written on the subject at my request. It would therefore be superfluous for me to say anything either in regard to their situation or structure. I have to observe, however, that in these double organs resides the electricity of the torpedo, the rest of his body appearing to be no otherwise concerned in his electrical effect than as conducting it; that they are subject to the will of the animal; but whether, like other double parts so controlable, they are exercised at times singly as well as in concert, is difficult to be ascertained by experiment : that their upper and under surfaces are capable, from a state of equilibrium with respect to electricity, of being instantly thrown, by a mere energy, into an apposition of a plus and minus state, like that ofthe charged phial: that when they are thus charged, the upper surfaces of the two are in the same state of electricity; as are the under surfaces of the two, though in a contrary to that ofthe upper; for no shock can be obtained by an insulated person touching both organs above, or both below : and that the production of the effect depends solely on an intercourse being made between the opposite surfaces of the organs, whether taken singly or jointly. * Kaempf. Amcen. Exct. 1712, p. 514. OF THE ELECTRIC PROPERTY OF THE TORPEDO. 403

All the parts bordering on the organs act more or less as conductors, either through their substance or by their superficies. While an insulated person, placing two fingers on the same surface of one or both organs, cannot be affected, if he removes one of his fingers to any such contiguous part he will be liable to a shock ; but this shock will not be near, perhaps not half so violent as one taken immediately between the opposite surfaces of the organ, which shows the conduction to be very imperfect. The parts which conduct the best are the two great lateral fin3 bounding the organs outwardly, and the space lying between the two organs inwardly. All below the double transverse cartilages scarcely conduct at all, unless when the fish is just taken out of water and is still wet, the mucus with which he is lubricated showing itself as it dries to be of an insulating nature. The organs themselves when uncharged appeared to be, not interiorly we might suppose, but rather exteriorly, conductors of a shock. An insulated person touching two torpedos, lying near one another on a damp table, with fingers placed, one on the organ of one fish, and another on the organ of the other, was sensible of shocks, sometimes delivered by one fish, and sometimesby the other, as might be discovered by the respective winking of their eyes. That the organs uncharged served some way or other as conductors, was confirmed with artificial electricity, in passing shocks by them, and in taking sparks from them when electrified. The electric effect was never perceived by us to be attended with any motion or alteration in the organs themselves, but was frequently accompanied with a little transient agitation along the cartilages which surround both organs: this is not discernible in the plump and turgid state of the animal while he is fresh and vigorous : but as his force decays, from the relaxation of his muscles, his cartilages appear through the skin, and then the slight action along them is discovered. May we not from all these premises conclude, that the effect of the torpedo proceeds from a modification of the electric fluid 1 The torpedo resembles the charged phial in that characteristic point of a reciprocation between its two surfaces. Their effects are transmitted by the same mediums; than which there is not perhaps a surer criterion to determine the identity of subtile matter: they besides occasion the same impression on our nerves. Like effects have like causes. But it may be objected, that the effects ofthe torpedo, and of the charged phial, are not similar in all their circumstances ; that the charged phial occasions attractive or repulsive dispositions in neighbouring bodies ; and that its discharge is obtained through a portion of air, and is accompanied with light and sound ; nothing of which occurs with respect to the torpedo. The inaction of Ihe electricity of the animal in these particulars, whilst its elastic force is so great as to transmit the effect through an extensive circuit and in its course to communicate a shock, may be a new phenomenon, but is no ways repugnant to the laws 404 HUNTER ON THE ANIMAL CECONOMY. of electricity, for here too the operations of the animal may be imitated by art. The same quantity of electric matter, according as it is used in a dense or rare state, will produce the different consequences. For example, a small phial, whose coated surface measures only six square inches, will, on being highly charged, contain a dense electricity capable of forcing a passage through an inch of air, and afford the phasnomena of light, sound, attraction, and repulsion. But if the quantity condensed in this phial be made rare by communicating it to three large connected jars, whose coated surfaces shall form together an area four hundred times larger than that of the phial (I instance these jars because they are such as I use); it will, thus dilated, yield all the negative phasnomena, if I may so call them, ofthe torpedo; it will not now pass the hundredth part of that inch of air which in its condensed state it sprung through with ease; it will now refuse the minute intersection in the strip of tinfoil; the spark and its attendant sound, even the attraction or repulsion of light bodies, will now be wanting; nor will a point brought however near, if not in contact, be able to draw off the charge : and yet, with this diminished elasticity, the electric matter will, to effect its equilibrium, instantly run through a considerable circuit of different conductors, perfectly continuous, and make us sensible of an impulse in its passage. Let me here remark, that the sagacity of Mr. Cavendish in devising and his address in executing electrical experiments, led him the first to experience with artificial electricity, that a shock could be received from a charge which was unable to force a passage through the least space of air. But after the discovery that a large area of rare electricity would imitate the effect of the torpedo, it may be inquired, where is this large area to be found in the animal 1 We here approach to that veil of nature which man cannot remove. This, however, wc know, that from infinite division of parts infinite surface may arise, and even our gross optics tell us that those singular organs, so often mentioned, consist like our electric batteries of many vessels, call them cylinders or hexagonal prisms, whose superficies taken together furnish a considerable area. 37. ANATOMICAL OBSERVATIONS ON THE TORPEDO.*

I was desired some time since, by Mr. Walsh, whose experiments at La Rochelle had determined the effect of the torpedo to

* [This paper was read before the Royal Society July 1, 1773, and published in the C3d volume ofthe Philosophical Transactions.] ANATOMICAL OBSERVATIONS ON THE TORPEDO. 405

be electrical, to dissect and examine the peculiar organs by which that animal produces so extraordinary an effect. This I have done in several subjects furnished to me by that gentleman. I am now desired by him to lay before the Society the observations I have made; and for the better understanding of them, to present, on his part, a male and female torpedo in spirits; in the latter of which the electric organs are exposed in different views and sections; likewise a copper-plate, which he took care to have engraved, exhibiting those organs. Of the general structure and anatomy of the torpedo I say nothing, since the animal does not differ very materially, excepting in its electric organs (as they have been properly named by Mr. Walsh), from the rest of the rays, of which family it is well known to be. I will only premise that the torpedo, of which I treat, is about eighteen inches long, twelve broad, and in its central or thickest part two inches thick; which is nearly the size of the female specimen now presented to the Society, as well as of that from which the plate was taken : but where there is any difference in the organ arising from difference in size, notice will be taken of it in this account. The electric organs of the torpedo are placed on each side ofthe cranium and gills, reaching from thence to the semicircular cartilages of each great fin, and extending longitudinally from the anterior extremity of the animal to the transverse cartilage which divides the thorax from the abdomen; and within these limits they occupy the whole space between the skin of the upper and of the under surfaces: they are thickest at the edges near the centre of the fish, and become gradually thinner towards the extremities. Each electric organ, at its inner longitudinal edge, is unequally hollowed, being exactly fitted to the irregular projection of the cranium and gills. The outer longitudinal edge is a convex elliptic curve. The anterior extremity of each organ makes the section of a small circle; and the posterior extremity makes nearly a right angle with the inner edge. Each organ is attached to the surrounding parts by a close cellular membrane, and also by short and strong tendinous fibres which pass directly across from its outer edge to the semicircular cartilages. They are covered above and below by the common skin ofthe animal, under which there is a thin fascia spread over the whole organ. This is composed of fibres, which run longitudinally, or in the direction of the body of the animal: these fibres appear to be perforated in innumerable places, which gives the fascia the appearance of being fasciculated ; its edges all around are closely connected to the skin, and at last appear to be lost, or to degenerate into the common cellular membrane ofthe skin. Immediately under this is another membrane exactly of the same kind, the fibres of which in some measure decussate those ofthe former, passing from the middle line of the body outwards and backwards. The inner edge of this is lost with the first described; 406 HUNTER ON THE ANIMAL CECONOMY. the anterior, outer, and posterior edges are partly attached to the semicircular cartilages, and partly lost in the common cellular membrane. This inner fascia appears to be continued into the electric organ by so many processes, and thereby makes the membranous sides or sheaths of the columns, which are presently to be described; and between these processes the fascia covers the end of each column, making the outermost or first partition. Each organ of the fish under consideration* is about five inches in length, and at the anterior end three in breadth, though it is but little more than half as broad as at the posterior extremity. Each consists wholly of perpendicular columns, reaching from the upper to the under surface of the body, and varying in their lengths according to the thickness of the parts of the body where they are placed; the longest column being about an inch and a half, the shortest about one-fourth of an inch in length, and their diameters about two-tenths of an inch. The figures of the columns are very irregular, varying according to situation and other circumstances. The greatest number of them are either irregular hexagons or irregular pentagons; but from the irregularity of some of them it happens that a pretty regular quadrangular column is sometimes formed. Those of the exterior row are either quadrangular or hexagonal, having one side external, two lateral, and either one or two internal. In the second row they are mostly pentagons. Their coats are very thin, and seem transparent, closely connected with each other, having a kind of loose network of tendinous fibres, passing transversely and obliquely between the columns, and uniting them more firmly together. These are mostly observable where the large trunks of the nerves pass. The columns are also attached by strong inelastic fibres, passing directly from one to the other. The number of columns in different torpedos of the size of that now offered to the Society appeared to be about 470 in each organ, but the number varies according to the size of the fish.f These columns increase, not only in size, but in number, during the growth of the animal; new ones forming perhaps every year on the exterior edges, as there they are much the smallest. This process may be similar to the formation of new teeth in the human jaw as it increases. Each column is divided by horizontal partition placed over each other, at very small distances, and forming numerous interstices, which appear to contain a fluid. These partitions consist of a very thin membrane, considerably transparent. Their edges appear to be attached to one another, and the whole is attached by

* [This specimen was eighteen inches long, twelve inches broad, and in its central or thickest part two inches thick.] f In a very large Torpedo, (see the preparation No. 2176, Physiological Series,) the number of columns in one electric organ were 1182. ANATOMICAL OBSERVATIONS ON THE TORPEDO. 407

a fine cellular membrane to the inside of the columns. They are not totally detached from one another: I have found them adhering at different places by blood-vessels passing from one to another. The number of partitions contained in a column of one inch in length, of a torpedo which had been preserved in proof spirit, appeared on a careful examination to be one hundred and fifty; and this number in a given length of column appears to be common to all sizes in the same state of humidity, for by drying they may be greatly altered; whence it appears probable that the increase in the length of a column, during the growth of the animal, does not enlarge the distance between each partition in proportion to that growth; but that new partitions are formed, and added to that extremity of the column from the fascia. The partitions are very vascular;* the arteries are branches from the vessels of the gills which convey the blood that has received the influence of respiration. They pass along with the nerves to the electric organ, and enter with them ; then they ramify in every direction into innumerable small branches upon the sides ofthe columns, sending in from the circumference all around upon each partition small arteries, which ramify and anastomose upon it, and passing also from one partition to another, anastomose with the vessels of the adjacent partitions. The veins of the electric organ pass out close to the nerves and run between the gills to the auricle of the heart. The nerves inserted into each electric organ arise by three very large trunks from the lateral and posterior part of the brain. The first of these in its passage outwards turns round a cartilage of the cranium and sends a few branches to the first gill, and to the anterior part ofthe head, and then passes into the organ towards its anterior extremity/}- The second trunk enters the giils between the first and second openings, and after furnishing it with small branches passes into the organ near its middle. The third trunk, after leaving the skull, divides itself into two branches, which pass to the electric organ through the gills; one between the second and

* [See prep. 2176, which is the section of a Torpedo, of very large size, taken in Torbay in August, 1774. It weighed fifty-three pounds, was four feet in length, two feet and a half in breadth, and four inches and a half in thickness. .Mr. Hunter having received this fish in a recent state was enabled to inject it, and thus demonstrate the vascularity of the electrical organs.] t [This nerve is a part of the third division of the fifth pair, and does not greatly exceed the size of the corresponding nerve in other species of the ray tribe; it distributes branches to the mucous tubes, which are fewer in number in. the torpedo than in the ordinary rays, before it penetrates the electric organ. The other great fasciculi of nerves correspond with the pneumogastric, or eighth pair of nerves : a large branch is continued from the most posterior to the stomach, where it is spread over the great arch. Dr. John Davy conjectures that the superfluous electricity when not required for the defence ofthe animal may be directed to this organ to promote digestion. In the instance of a Torpedo which he preserved alive for many days, and which was frequently excited to give shocks,digestion appeared to have been completely arrested ; when it died, a small fish was found in its stomach, much in the same state in which it was swallowed ; no portion of it had been dissolved.] 408 HUNTER ON THE ANIMAL CECONOMY. third openings, the other between the third and fourth, giving small branches to the gills itself. These nerves having entered the organs ramify in every direction between the columns, and send in small branches upon each partition, where they are lost. The magnitude and the number of the nerves bestowed on these organs, in proportion to their size, must on reflection appear as extraordinary as the phenomena they afford. Nerves are given to parts either for sensation or action. Now if we except the more important senses of seeing, hearing, smelling, and tasting, which do not belong to the electric organs, there is no part even ofthe most perfect animal which, in proportion to its size, is so liberally supplied with nerves ; nor do the nerves seem necessary for any sensation which can be supposed to belong to the electric organs. And with respect to action, there is no part of any animal with which I am acquainted, however strong and constant its natural actions may be, which has so great a proportion of nerves. If it be then probable that no nerves are not necessary for the purposes of sensation or action, may we not conclude that they are subservient to the formation, collection, or management of the electric fluid 1 especially as it appears evident, from Mr. Walsh's experiments, that the will of the animal does absolutely control the electric powers of its body, which must depend on the energy ofthe nerves. How far this may be connected with the powers ofthe nerves in general, or how far it may lead to an explanation of their operations, time and future discoveries alone can fully determine. 38. AN ACCOUNT OF THE GYMNOTUS ELECTRICUS.*

To Mr. Walsh, the first discoverer of animal electricity, the learned will be indebted for whatever the following pages may contain, either curious or useful. The specimen of the animal which they describe was procured by that gentleman, and at his request this dissection was performed and this account of it is communicated. This fish on the first view appears very much like an eel, from which resemblance it has most probably got its name; but it has none of the specific properties of that fish. This animal may be considered, both anatomically and physiologically, as divided into two parts, viz., the common animal part, and a part which is superadded, viz. the peculiar organ. I shall at present consider it only with respect to the last, as the first explains nothing relating to the

* [This paper was read before the Royal Society May 11, 1775, and published in the 65th volume ofthe Philosophical Transactions.] AN ACCOUNT OF THE GYMNOTUS ELECTRICUS. 409

other, nor anything relating to the animal ceconomy of fish in general. The first, or common animal part, is so contrived as to exceed what was necessary for itself, in order to give situation, nourishment, and most probably the peculiar property to the second. The last part, or peculiar organ, has an immediate connexion with the first, the body affording it a situation, the heart nourishment, and the brain nerve, and probably its peculiar powers. For the first of these purposes the body is extended out in length, being much longer than would be sufficient for what may be called its progressive motion. For the real body, or that part where the viscera and parts of generation lie, is situated, with respect to the head, as in other fish, and is extremely short, so that, according to the ordinary proportions, this should be a very short fish. Its great length, therefore, seems chiefly intended to afford the surface for the support of the peculiar organ ; however, the tail part is likewise adapted to the progressive motion of the whole and to preserve the specific gravity; for the spine, medulla spinalis, muscles, fin, and air-bladder* are continued through its whole length. Besides which parts there is a membrane passing from the spine to that fin which runs along the belly or lower edge of the animal. This membrane is broad at the end next to the head, terminating in a point at the tail; it is a support for the abdominal fin, gives a greater surface of support for the organ, and makes a partition between the organs of the two opposite sides.

The organs which produce the peculiar effect of this fish constitute nearly one-half of that part of the flesh in which they are placed, and perhaps make more than one-third of the whole animal. There are two pair of these organs, a larger and smaller, one being placed on each side. The large pair occupy the whole lower or anterior, and also the lateral part of the body, making the thickness of the fore or lower parts of the animal; and run almost through its whole length, viz., from the abdomen to near the end of the tail. It is broadest on the sides of the fish at the anterior end, where it incloses more of the lateral parts of the body, becomes narrower towards the end of the tail, occupying less and less ofthe sides of the animal, tjll at last it ends almost in a point. These two organs are separated from one another at the upper part by the muscles of the back which keep their posterior or upper edges at a considerable distance from one another ; below that, and towards the middle, they are separated by the air-bag, and at their lower parts they are separated by the middle partition. They begin for-

* [The Gymnotus electricus has two air-bladders, one of which, of an oval form and bilobed, is situated at the anterior part of the abdomen, beneath the oesophagus; the other is the elongated sac described by Hunter, and extended through the posterior part of the body. In another species, the Gymnotus xquilabiatus of Humboldt, the posterior elongated air-bladder is wanting.] 36 410 HUNTER ON THE ANIMAL CECONOMY. wards by a pretty regular edge, almost at right angles with the longitudinal axis of the body, situated on the lower and lateral parts of the abdomen. Their upper edge is a pretty straight line, with small indentations made by the nerves and blood-vessels which pass round it to the skin. At the anterior end they go as far towards the back as the middle line of the animal, but in their approach towards the tail they gradually leave that line, coming nearer to the lower surface ofthe animal. The general shape ofthe organ, on an external or side view, is broad at the end next to the head ofthe animal, becoming gradually narrower towards the tail, and ending there almost in a point. The other surfaces of the ororan are fitted to the shape of the parts with which they come in contact, therefore on the upper and inner surface it is hollowed to receive the muscles of the back. There is also a longitudinal depression on its lower edge, where a substance lies which divides it from the small organ, and which gives a kind of fixed point for the lateral muscles ofthe fin. Its most internal surface is a plane adapted to the partition which divides the two organs from one another. The edge next to the muscles of the back is very thin, but the organ becomes thicker and thicker towards the middle, where it approaches the centre ofthe animal. It becomes thinner again towards the lower surface or belly, but that edge is not so thin as the other. Its union w>ith the parts to which it is attached is in general by a loose but pretty strong cellular membrane, except at the partition, to which it is joined so close as to be almost inseparable. The small organ lies along the lower edge ofthe animal, nearly to the same extent as the other. Its situation is marked externally by the muscles which move the fin under which it lies. Its anterior end begins nearly in the same line with the large organ, and just where the fin begins. It terminates almost insensibly near the end ofthe tail, where the large organ also terminates. It is of a triangular figure, adapting itself to the part in which it lies. Its anterior end is the narrowest part; towards the tail it becomes broader; in the middle of the organ it is thickest, and from thence becomes gradually thinner to the tail, where it is very thin. The two small organs are separated from one another by the middle muscles, and by the bones upon which the bones of the fins are articulated. The large and the small organ on each side are separated from one another by a fatty membrane, the inner edge of which is attached to the middle partition, and its outer edge is lost on the skin ofthe animal. To expose the large organ to view nothing more is necessary than to remove the skin, which adheres to it by a loose cellular membrane; but to expose the small organ it is necessary to remove the long row of small muscles which move the fin.

Ofthe Structure of these Organs. The structure is extremely simple and regular, consisting of two parts, viz., flat partitions of septa, and cross divisions between them. AN ACCOUNT OF THE GYMNOTUS ELECTRICUS. 411

The outer edges of these septa appear externally in parallel lines nearly in the direction ofthe longitudinal axis ofthe body. These septa are thin membranes, placed nearly parallel to one another. Their lengths are nearly in the direction ofthe long axis, and their breadth is nearly the semi-diameter of the body of the animal. they are of diflerent lengths, some being as long as the whole organ. I shall describe them as beginning principally at the anterior end ofthe organ, although a few begin along the upper edge, and the whole, passing towards the tail, gradually terminate on the lower surface of the organ; the lowermost at their origin terminating soonest. Their breadths differ in different parts of the organ. They are in general broadest near the anterior end, answering to the thickest part ofthe organ, and become gradually narrower towards the tail; however, they are very narrow at their beginnings or anterior ends. Those nearest to the muscles ofthe back are the broadest, owing to their curved or oblique situation upon these muscles, and grow gradually narrower towards the lower part, which is in a great measure owing to their becoming more transverse, and also to the organ becoming thinner at that place. They have an outer and an inner edge; the outer is attached to the skin ofthe animal, to the lateral muscles of the fin, and to the membrane which divides the great organ from the small, and the whole of their inner edges are fixed to the middle partition formerly described, also to the air-bladder, and three or four terminate on that surface which inclose the muscles of the back. These septa are at the greatest distance from one another at their exterior edges near the skin, to which they are united ; and as they pass from the skin towards their inner attachments they approach one another. Sometimes we find two uniting into one. On that side next to the muscles ofthe back they are hollow from edge to edge, answering to the shape of those muscles, but become less and less so towards the middle of the organ, and from that towards the lower part of the organ they become curved in the other direction. At the anterior part of the large organ, where it is nearly of an equal breadth, they run pretty parallel to one another, and also pretty straight, but where the organ becomes narrower it may be observed in some places that two join or unite into one, especially where a nerve passes across. The termination of this organ at the tail is so very small that I could not determine whether it consisted of one septum or more. The distances between these septa will differ in fishes of different sizes. In a fish of two feet four inches in length I found them jV of an inch distant from one another, and the breadth of the whole organ, at the broadest part, about an inch and a quarter, in which place were thirty-four septa. The small organ has the same kind of septa, in length passing from end to end ofthe organ, and in breadth passing quite across; they run somewhat serpentine, not exactly in straight lines. Their outer edges terminate on the outer surface of the organ, which is in contact with the inner surface ofthe external muscle ofthe fin, and their inner edges are 412 HUNTER ON THE ANIMAL CECONOMY.

in contact with the centre muscles. They differ very much in breadth from one another, the broadest being equal to one side of the triangle, and the narrowest scarcely broader than the point or edge. They are pretty nearly at equal distances from one another, but much nearer than those ofthe large organ, being only about ^ part of an inch asunder ; but they are at a greater distance from one another towards the tail, in proportion to the increase of breadth ofthe organ. The organ is about half an inch in breadth', and has fourteen septa. These septa, in both organs, are very tender in consistence, being easily torn. They appear to answer the same purpose with the columns in the torpedo, making walls or hutments for the subdivisions, and are to be considered as making so many distinct organs. These septa are intersected transversely by very thin plates or membranes, whose breadth is the distance between any two septa, and therefore of different breadths indifferent parts, broadest at that edge which is next to the skin, narrowest at that next to the centre of the body, or to the middle partition which divides the two organs from one another. Their lengths are equal to the breadths of the septa, between which they are situated. There is a regular-series of them continued from one end of any two septa to the other. They appear to be so close as even to touch. In an inch in length there are about two hundred and forty, which multiplies the surface in the whole to a vast extent.

Ofthe Nerves. The nerves in this animal may be divided into two kinds, the first appropriated to the general purposes of life, the second for the management of this peculiar function, and very probably for its existence. They arise in general from the brain and medulla spinalis, as in other fish, but those from the medulla are much larger than in fish of equal size, and larger than is necessary for the common operations of life. The nerve which arises from the brain and passes down the whole length ofthe animal (which I believe exists in all fish) is larger in this than in others of the same size, and passes nearer to the spine. In the common eel it runs in the muscles of the back, about midway between the skin and spine. In the cod it passes immediately under the skin. From its being larger in this fish than in others of the same size one might suspect that it was intended for supplying the organ in some degree; but this seems not to be the case, as I was not able to trace any nerves going from it to join those from the medulla spinalis, which run to the organ. This nerve is as singular an appearance as any in this class of animals; for surely it must appear extraordinary that a nerve should arise from the brain to be lost in common parts while there is a medulla spinalis giving nerves to the same parts. It must still remain one of the inexplicable circumstances of the nervous system.* * [This remarkable nerve, the nervus lateralis, is, in the Gymnotus, a branch of the nervus vagus. It does not exist in the myxine, but in the higher cartilaginous fishes it is largely developed. In the rays it extends from the occiput to the end of the tail, even where this, as in the Raia fasciata, is six times AN ACCOUNT OF THE GYMNOTUS ELECTRICUS. 413 The organ is supplied with nerves from the medulla spinalis, from which they come out in pairs between all the vertebras of the spine. In their passage from the spine they give nerves to the muscles of the back, &c. They bend forwards and outwards upon the spine, between it and the muscles, and send out small nerves to the external surface, which join the skin near to the lateral lines. These ramify upon the skin, but are principally bent forwards between it and the organ, into which they send small branches as they pass along. They seem to be lost in these two parts. The trunks get upon3the air-bladder, or rather dip between it and the muscles of the back, and continuing their course forwards upon that bag, they dip in between it and the organ, where they divide into smaller branches; then they get upon the middle partition, on which they continue to divide into still smaller branches; after which they pass

the length ofthe body; and in the trunk the two nerves exceed tto size of the spinal chord. In osseous fishes it is relatively smaller, and in some species, as the cod, is formed by a combination of a branch of the fifth with a filament ofthe eighth or nervus vagus. Besides the class of fishes (with the exception of the myxine), the lateral nerve is also present in those reptiles which preserve throughout life the external branchiae or the branchial apertures, and which reside habitually in water, and move, like fish, by the actions of a caudal fin. In the Menobranchus the nervus lateralis forms a large branch of the nervus vagus, and passes superficially beneath the skin as far back as the middle ofthe tail, where it joins the filaments of the spinal nerves. In the proteus the nervus vagus sends off on each side two nervi laterales, one deep-seated, the other superficial. In the menopome the lateral nerve is likewise present, but is much more delicate than in the Perennibranchiata with external gills. In ihe larva of the Rana paradoxa the lateral nerve may be observed beneath the skin in the longitudinal fissure which separates the two large muscular fasciculi of the tail on each side. After the full formation of the anterior extremities this nerve becomes gradually more attenuated, and finally disappears with the absorption of the tail. It does not exist in the anourous batrachia. We may thus perceive a relationship of coexistence to subsist between these enigmatical nerves and branchial respiration. This imperfect kind of respiration is assisted by the vascularity and active powers of excreting mucus in the whole or a part ofthe external tegument. In the osseous fishes a linear series of mucous follicles is extended along eacli side of the body, and the lateral nerves, which run parallel with these lines give numerous branches to the mucous sacs and the neighbouring skin ; and in the Perennibranchiata the lateral nerves are exclusively distributed to the skin: hence they might be termed the cutaneous respiratory nerves. They do not supply the muscles along which they pass: these derive their nervous energy from ihe ordinary spinal nerves. When irritated or galvanized the lateral nerves excite no contractions in the muscles; they are therefore not analogous to the spinal accessory nerves in the mammalia. In the Gymnotus Mr. Hunter was not able to trace any nerves going from the lateral nerve to join those from the medulla spinalis which supply the electric organ, but it anastomoses with the spinal nerves which supply the caudal fin. And in the cod, where this anastomosis takes place at each of the numerous fins, Mr. Swan conjectures that its function may be to produce sympathy and harmonious cooperation, and to regulate and produce, independently ofthe will, the action ofthe muscles of these parts. (See his accurate and beautiful Illustrations of the Comparative Anatomy of the Nervous System, p. 26, pi. vii.) And this theory equally agrees with the laws of coexistence of the lateral nerve3 as established by an extensive induction of particular dissections.] 36* 414 HUNTER ON THE ANIMAL CECONOMY. on and get upon the small bones and muscles, which are the bases for the under fin, and at last they are lost on that fin. After having got between the organ and the above-mentioned parts they are constantly sending small nerves into the organs, first into the great organ and then into the small one; also into the muscles of the fin, and at last into the fin itself. These branches, which are sent into the organ as the trunk passes along, are so small that 1 could not trace their ramifications in the organs. In this fish, as well as in the torpedo, the nerves which supply the organ are much larger than those bestowed on any other part for the purposes of sensation and action; but it appears to me that the organ of the torpedo is supplied with much the largest proportion. If all the nerves which go to it were united together they would make a vastly greater chord than all those which go to the organ of this eel. Perhaps when experiments have been made upon this fish, equally accurate with those made upon the torpedo, the reason for this difference may be assigned. Blood- Vessels. How far this organ is vascular I cannot positively determine, but from the quantities of small arteries going to it I am inclined to believe that it is not deficient in vessels. The arteries arise from the large artery which passes down the spine ; they go off in small branches like the intercostals in the human subject, pass round the air-bladder, and get upon the partition together with the nerves, and distribute their branches in the same manner. The veins take the same course backwards, and enter the large vein which runs parallel with the artery. [A vivid and interesting account of the mode of capture ofthe gymnotus, and the power of its electric shocks, is given by Humboldt in his Observations de Zoologie et d"1 Anatomie Comparee, vol. i., p. 49. An abstract of these observations will be found in the Cyclopaedia of Anatomy and Physiology, art. 'Animal Electricity,' from which, towards completing the view of this interesting subject, we quote the following description of the electrical organs in the Silurus or Malapterurus electricus, a fish inhabiting the rivers Nile and Niger.

" The Electrical Organs in the Silurus. " The only organ that can be regarded as connected with the electrical function in this fish is a thick layer of dense cellular tissue, which completely surrounds the body immediately beneath the integuments. So compact is it that at first sight it might be mistaken for a deposit of fatty matter. But under the microscope it appears to be composed of tendinous fibres, closely interwoven, the meshes of which are filled with a gelatinous substance. " This organ is divided by a strong aponeurotic membrane into two circular layers, one outer lying immediately beneath the corion, the other internal, placed above the muscles. OBSERVATIONS ON BEES. 415 " Both organs are isolated from the surrounding parts by a dense fascia, excepting where the nerves and blood-vessels enter. The cells or meshes in the outer organ, formed by its reticulated fibres, are rhombic in shape, and very minute, so as to require a lens to see them well. The component tissue of the inner organ is somewhat flaky, and also cellular. " The nerves of the outer organ are branches of the fifth pair, which runs beneath the lateral line, and above the aponeurotic covering of the organ. This aponeurosis is pierced with many holes for the transmission ofthe nerves, which are lost within the cellular tissue ofthe organ. The intercostals supply the inner organ : their electrical branches are numerous, and remarkably fine. The organs of the other known electrical fishes have not yet come under the notice of any anatomist. In taking a general view of these interesting organs, we are struck with the existence of a certain degree of analogy amongst them, and yet we fail to discover such resemblances as might be expected, and such as exist between the structures of other organs performing the same functions in different animals. Here we have tendinous membranes variously arranged, yet all so as to form a series of separate cells, filled with a gelatinous matter. But how great is the difference between the large columnal cell in the torpedo, full of delicate partitions, and the minute rhombic cells of the silurus! " All, however, are equally supplied with nerves of very great size, larger than any others in the same animals, and indeed we may venture to say, larger than any nerve in any other animal of like bulk. The organs vary in different fishes; first, in situation, relatively to other organs. They bound the sides of ihe head in the torpedo, run along the tail ofthe gymnotus, and surround the body ofthe silurus : secondly, in having different sources of nervous energy: and thirdly, in the form of the cells. No olher fishes have aponeuroses so extensive, or such an accumulation of gelatin and albumen in any cellular organ. Broussonet remarked that all the electrical fishes at present known to us, although all belonging to different classes, have yet certain characters in common. All, for instance, have the skin smooth, without scales, thick, and pierced with small holes, most numerous about the head, and which pour out a peculiar fluid. Their fins are formed of soft and flexible rays, united by means of dense membrane?. Neither the gymnotus nor torpedo has any dorsal fin ; the silurus has only a small one without rays, situated near the tail. All have small eyes."] OBSERVATIONS ON BEES.*

Of the Common Bee. The common bee, from a number of peculiarities in its ceconomy, has called forth the attention of the curious, and from the profit arising from its labours, it has become the object ofthe interested ; therefore no wonder it has excited universal attention, even from * [This paper was read before the Royal Society, February 23, 1792, and published in the 82d volume of the Philosophical Transactions.] 416 HUNTER ON THE ANIMAL CECONOMY. the savage to the most civilized people; but it has hardly been considered by the anatomist, at least the two modes of investigation have not gone so much hand in hand as they ought to have done. The history of the bee has rather been considered as a fit subject for the curious at large, whence more has been conceived than observed. Swammerdam, indeed, has rather erred on the other side, having with great industry been very minute on the particular structure of the bee. I shall here observe that it is commonly not only unnecessary to be minute in our description of parts in natural history, but in general improper. It is unnecessary when it does not apply to anything but the thing itself, more especially if it be of no consequence ; but whenever it applies, then it should so far be treated accurately. Minutias beyond what is essential, tire the mind, and render that which should entertain along with instruction heavy and disagreeable ; the more so too if the parts are small, where the sense can only take them in singly, and the mind can hardly comprehend the whole or apply all the parts combined to any consequent action. This has been too much the case with Swammerdam; he often attempted too much accuracy in his description of minute thing.* But the natural history of insects has not been sufficiently understood at large, so as to throw light on this subject where there was an analogy, and where without such analogy, it must appear in the bee alone unintelligible, from the obscurity attending some parts of their ceconomy; for there is hardly any species of animals but what has some part of its ceconomy obscure, and probably this is as much so in this insect as in any other class of animals wc are at one season ofthe year almost daily seeing; yet these parts of the ceconomy may be evident in some other species of the same tribe or genus, and thus be cleared up, from analogy, so that the species assist each other in their demonstration. This is evident in the whole tribe of flying insects, for what is lost or cannot be made out in the one may be demonstrated in another ; and we find there are some things in the ceconomy of the bee that cannot be seen or demonstrated in it alone, but which are evident in some other insects; and while they possess the same parts, and other circumstances are similar, we must conclude the uses of those parls are similar in both ; for whenever a circumstance in one animal cannot be found out in that animal, but can in another, then the natural conclusion is that the uses are similar in both. Though the bee may be classed in some degree among the * [If thu objects of the comparative anatomist were limited to the elucidation of the function of the organs he dissected, there might ihe.n, perhaps* be some reason in the animadversions in the text; but his researches have a still higher aim, viz., to trace the general plan which pervades the construction of aniniali amidst the various modifications to which each organ is subject in reference to particular functions; and the study of organic homologies requires that attention be paid to the minutest particulars, independently of consideration* as to the uses in the ceconomy to which they may be subservient.] OBSERVATIONS ON BEES. 417

domestic animals, yet from there being such a cluster of them, and because they are an offensive and irritable animal, their actions are rendered very obscure, and can only be observed by little starts; often we can only see the effects, which renders the knowledge of their ceconomy still imperfect: they would in many cases seem to evade our wishes; they often remove out of our sight part of their ceconomy when they can. Thus they often remove their eggs and young. Many quadrupeds do this, as cats, &c, and I have reason to believe that birds can remove their eggs, at least I have reason to suspect the sparrow of this. As the bee is an insect, it has most things peculiar to that class of animals: such as are common are not to be taken notice of in the history of this insect, but only its peculiarities which distinguish it from all others, and constitute it to be a bee ; and as bees form a large tribe of insects, it is the more singular peculiarities that constitute a distinct species of this tribe. As most parts of the ceconomy of insects have not been in every respect understood, and although now known in some insects yet cannot be observed in the bee, but which accord with many circumstances attending this insect, therefore such must be brought into the present history of the bee to render it more complete. I shall not be minute in the anatomy of this animal, as that would be too tedious and uninteresting. When we talk of the ceconomy of the colony, such as the secreting wax, making combs, collecting farina, honey, feeding the maggots, covering in the chrysalis and the honey, stinging, &c, it is the labouring bees that are meant. In pursuing any subject most things come to light as it were by accident, that is, many things arise out of investigation that were not at first conceived, and even misfortunes in experiments have brought things to our knowledge that were not and probably could not have been previously conceived: on the other hand, I have often devised experiments by the fire-side or in my carriage, and have also conceived the result; but when I tried the experiment the result was different, or I found that the experiment could not be attended with all the circumstances that were suggested. As bees, from their numbers, hide very much their operations, it is necessary to have such contrivances as will explore their oeconomy. Hives with glass lights in them often show some of their operations, and when wholly of glass still more ; but as they form such a cluster, and begin their comb in the centre, little can be seen till their work becomes enlarged, and by that time they have produced a much larger quantity of bees, so as still to obscure their progress. Very thin glass hives are the best calculated for exposing their operations; the distance from side to side about three inches; of a height and length sufficient for a swarm of bees to complete one summer's work in. As one perpendicular comb, the whole length and height of the hive, in the centre, dividing it into two, is the best position for exposing their operations; it is necessary to give them a lead or direction to form it so; therefore 418 HUNTER ON THE ANIMAL CECONOMY. it is proper to make a ridge along the top from end to end, in the centre, between the two sides, for they like to begin their comb from an eminence; if we wished to have them transverse or oblique, it would only be necessary to make transverse or oblique ridges in the hive. I had one made of two broad pieces of plateglass,- with glass ends, which answered fqj simple exposure very well; but I often saw operations going on when I wished to have caught some of the bees, or to take out a piece of comb, &c.; therefore I had hives made of the same shape and size, but with different panes of glass, each pane opening with hinges, so that if I saw anything going on that I wished to examine more minutely or immediately, 1 opened the pane at this part and executed what I wished as much as was in my power; this I was obliged to do with great caution, as often the comb was fastened to the glass at this part. When I saw some operations going on, the dates or periods of which I wished to ascertain, such as the time of laying eggs, of hatching, &c, I made a little dot with white paint opposite to the cell where the egg was laid and put down the date. From these animals forming colonies, and from a vast variety of effects being produced, and with a degree of attention and nicety that seem even to vie with man, man, not being in the least jealous, has wished to bestow- on them more than they possess, viz., a reasoning faculty; while every action is only instinctive, and what they cannot avoid or alter except from necessity, not from fancy. They have been supposed to be legislators, even mathematicians; indeed, upon a superficial view there is some show of reason for such suppositions; but people have gone much further, and have filled up from their imagination every blank, but in so unnatural a way that one reads it as if it were the description of a monster. Probably the best way of treating the history of this insect is only to describe what is, and the reader will immediately see where authors have been inventing ; however, there are some assertions that should be particularly taken notice of, such as forming queen bees at pleasure. Countries that have but little variety in their seasons may have insects whose ceconomy is w?ell adapted to this uniformity, and which would not be suited to a climate whose seasons are very different ; for insects of countries, whose seasons are strongly marked, as in this, have a period in their life which it is little in our power to investigate, and can scarcely be discovered but by accident, for experiments often give little assistance; therefore we are obliged to fill up this blank by reasoning, and from analogy, where we have any. This period is principally the winter, in those insects which live through that season. Animals of season are somewhat like most vegetables, while the common bee is only an animal of seasons in the common actions of life, or what may be called its voluntary actions, and therefore it is somewhat like the human species, suited to every country, which may be the reason why it is so universally an animal, fori believe bees are one ofthe most universal OBSERVATIONS ON BEES. 419 animals known ;* yet this may arise from cultivation, in consequence of which they have been brought into climates where of themselves they would not have come.f Insects are so small and so few of them are capable of being domesticated, that the duration of their life is not easily ascertained ; therefore we are to rely more on circumstantial than on positive or demonstrative proof, and perhaps the life of the common bee may be least in our power to know, for their numbers in the same society make it almost impossible to be ascertained. From their forming a colony or society, which keeps stationary, the continuance of this society is known, but to what age the individual lives is not known ; we are certain, however, that it is only the labourers and queens that continue the society, for the males die the same year they are formed. From their fixing on the branches of trees, under projecting exposed surfaces, when they swarm, we should be inclined to suppose that they were animals of a warm climate ; yet their providing liberally for the change of climate, or rather for a change of season, would, on the contrary, make us believe they were adapted for changeable climates, or rather these two circumstances should make us suppose they were fitted for both, and their universality proves it. And I do conceive that in a pretty uniform warm climate their ceconomy may be somewhat different from what it is in the changeable, as they would not be under the same necessity to lay up so much store, and probably might employ their cells in breeding, for a much longer period ; however, a good climate agrees with them best, as also a good season in an indifferent climate, such as Britain. We find the common bee in Europe, Asia, Africa, and America. That they may be, or should be, in the three first is easily supposed, but how they came to America is not so readily conceived; for although a kind of manageable animal, yet they do not like such long confinement in their hives as would carry them to the West Indies, excepting in an ice-house ; for when I have endeavoured to confine them in their hives they have been so restless as to destroy themselves. The female and the working bee, I believe in every species, have stings, which renders them an animal of offence, indeed, but rather of defence; for although they make an attack, I believe it is by way of defence, excepting when they attack one another, which is seldom or never with their stings. As this belongs more to the labourers, it shall be considered when I treat of them in particular. Of the whole bee tribe, the common bee is the easiest irritated ; for as

* [The humble bee was found by Captain Parry in Melville Island, Arctic circle.] f [The true honey bee (Apis melUfica) was originally limited in its geographical range to the old world, whence it has been transported to America and other colonies, where it is now acclimated. The distinguished entomologist Latreille, on whose authority we state this fact, finds that the hive bee of the south and east of Europe and that of Egypt differ specifically from the Apis melUfica of the west of Europe.] 420 HUNTER ON THE ANIMAL CECONOMY. they have properly, they are jealous of it, and seem to defend it; but when not near.it they are quiet, and must be hurt before they will sting; with all this disposition for defence, which is only to secure their property or themselves, when more closely attacked, yet they have no covetousness, nor a disposition to obstruct others. Thus two bees or more will be sucking at the same flower, without the first possessor claiming it as his right; a hundred may be about the same drop of honey, if it is beyond the boundaries of their own right; but what they have collected they defend. It is easily known when they mean to sting ; they fly about the object of their anger very quickly, and by the quickness of their motion evade being struck or attacked; which is discovered by the sound of their wings, as if going to give a stroke as they fly, a very diflerent noise from that of the wings when coming home of a fine evening loaded with farina or honey ; it is then a soft, contented noise. When a single bee is attacked by several others, it seems the most passive animal possible, making no resistance, and even hardly seeming to wish to get away; and in this manner they allow themselves to be killed. They are perhaps the only insect that feeds in the winter, and therefore the only one that lays up external store; and as all animals, whether insects or not, that keep quiet in the winter, without either eating at all, or eating very little in proportion to what they do in the summer, grow fat and muscular in the summer (which I term internal store), we see why the common bee need not be fatter at one time than another; and accordingly we find them nearly ofthe same fatness the year round. There are accidents befalling hives of bees that are not easily accounted for. I had a hive, which in the month of November was become quite empty of bees, and upon examination had no honey in it, which was strong in the summer, and had violent attacks made upon it in October by wasps belonging to a nest in the garden, but appeared quiet when that nest was removed. Upon examining this hive, I found only five dead bees, and not a drop of honey in any one cell: there was a good deal of bee bread in different cells scattered up and down the comb, which was become white with mould on its surface. On the other hand, I have had swarms die in the winter in the hives, while there was great plenty of honey in the combs ; what seemed remarkable, they all died with their proboscides elongated, and in those which I opened, I found the stomachs full of honey, and their intestines full also of excrement, especially the last part.

Of the Heat of Bees. Bees are perhaps the only insects that produces heat within itself,*

* [It has been long known that other social insects besides the bee maintain, when congregated in their habitations, a higher temperature than that of the external atmosphere. In an excellent and highly important series of experiments on this subject recently communicated by Mr. Newport to the Royal Society, it is shown that insects in general have the power of generating animal OBSERVATIONS ON BEES. 421 and were therefore intended to have a tolerably well-regulated warmth, without whiclr, of course, they are very uncomfortable and soon die; and which makes not only a part of their internal oeconomy respecting the individual, but a part of their external or common ceconomy, and is therefore necessary to be known. The heat of bees is ascertainable by the thermometer, and I shall give you the result of experiments made at two different seasons of the year. July 18th, at ten in the evening, wind northerly, thermometer at 54° in the open air, I introduced it into the top of a hive full of bees, and in less than five minutes it rose to 82°. I let it stand all night; at five in the morning it was down at 79°; at nine in the same morning it had risen to 83°, and at one o'clock to 84°; and at nine in the evening it was down to 78°. December 30th, air at 35°, bees at 73°. Although bees support a heat nearly equal to that of a quadruped, yet their external covering is not different from that of insects which do not; there is no difference between their coat and common fly's or wasp's, nor are they fatter, all which makes them bad retainers of heat; therefore they are chilly, and in a cold too severe for them to be comfortable in, they make up for their want of size singly and get into clusters. A single bee has so little power of keeping itself warm, that it presently becomes numbed, and almost motionless: a common night in summer will produce this effect. A cold capable of producing such effects kills them soon, by which means vast numbers die; therefore a common bee is obliged to feed and live in society to keep itself warm in cold weather. We know that the consumption of heat may be greater than the power of forming it; when that is the case we become sensible of it, and then take on such actions as are either instinctive, such as arise naturally out of the impression, or as reason, custom, or habit direct. Many animals upon the impression of cold, coil themselves up in their own fur, bringing all their extremities into the centre or hollow of the belly; birds bring their feet under the belly, and thrust their bill between their wing and body; many if not all, go to the warmest places, either from instinctive principle or habit; but the bees have no other mode but forming clusters, and the larger

heat; that that power in the solitary insects is greatest in the diurnal species of flying insects, especially such as reside most constantly in the open air. The law that the mature or more perfect animal is " more capable of generating heat than when it is younger" (see p. 159), is well exemplified by Mr. Newport in the class of insects. In the Lepidoptera, the average elevation ofthe temperature ofthe body above that of its surrounding medium is in the larvae from 0°.9, to 1°.5, while in the .imago it is from 5° to 10°. Among the Hyinenoptera it is from 2° to 4° in the larva, and in the imago from 4° to 15°, or even 20°. In all these cases the amount of animal heat developed is in the ratio of the consumption of oxygen and the quantity of carbonic acid formed in the change ofthe arterial into serous blood ; or in other word9, in proportion to the energy with which the functions of respiration and locomotion go on in the insect] 37 422 HUNTER ON THE ANIMAL CECONOMY. the better. As they are easily affected by cold, their instinctive principle respecting cold is very strong, as likewise with regard to wet. I have seen a swarm hanging out at the door of a hive ready to take flight, and then return; a chill has come on of which I was not sensible, and in a few minutes the whole has gone back into the hive; and by the cold increasing, I have at length perceived the cause of their return. If rain is coming on, we observe them returning home in great quantities, and hardly any abroad. The eggs of bees require this heat as much as themselves, nor will the maggot live in a cold of 60° or 70°, nor even their chrysalis. This warmth keeps the wax so soft as to allow them to model it with ease. In glass hives, or those that have windows of glass in them, we often find a dew on the inside of the glass, especially when the glass is colder than the air within ; whether this is perspiration from the bees, both from their external surface and lungs, or evaporation from the honey, I cannot say. Bees are very cleanly animals respecting themselves, although not so respecting the remains of their young. They, I believe, seldom or never evacuate their excrement in the hive. I have known them confined many days without discharging the contents of the rectum, and the moment they got abroad they evacuated in the air when flying; and they appear to be very nice in their bodies, for I have often detected them cleaning one another, more especially if by accident they are besmeared with honey. This animal may be considered alone, or so far as concerns its own ceconomy as an individual, which is common to the most solitary animals; but it can also be considered as a member of society, in which it is taking an active part, and in which it becomes an object of great curiosity. To consider this society individually, it may be said to consist of a female breeder, female non-breeders, and males; but to consider it as a community, it may be said to consist only of female breeders and non-breeders, the males answering no other purpose than simply as a male, and are only temporary; and it is probable the female breeder is to be considered in no other light than as a layer of eggs, and that she only influences the non-breeders by her presence, being only a bond of union, for without her they seem to have no tie ; it is her presence that makes them an aggregate animal. May we not suppose that the offspring of the queen have an attachment to the mother, somewhat similar to the attachment of young birds to the female that brings them up 1 for although the times of their attachment are not equal, yet it is the dependence which each has on its mother that constitutes the bond ; for bees have none without her: however, the similarity is not exact, for young animals who have lost their nurse will herd together, and jointly make the best shifts they can, because in future they are to become single animals; but bees have an eternal instinctive dependence on the mother, probably from there not being distinct sexes. When the queen is lost, this attachment is broke; they give up in- OBSERVATIONS ON BEES. 423 dustry, probably die, or we may suppose, join some other hive. This is not the case with those of this tribe whose queen singly forms a colony; for although 'the queen is destroyed, yet they go on with that work which is their lot, as the wasp, hornet, and humble bee. Most probably the whole ceconomy of the bee, which we so much admire, belongs to the non-breeders, and depends on their instinctive powers being set to work by the presence of the breeders, that being their only enjoyment; therefore when we talk of the wonderful ceconomy of bees, it is chiefly the labourers at large we are to admire, although the queen gets the principal credit for the extent of their instinctive properties. This ceconomy, in its appearances and operations, is somewhat similar to human society, but very different in its first causes and mode of conduct. The human species sets up its own standard; the bee has one set up by nature, and therefore fulfils all the necessary purposes. This standard of influence, which is the breeder, is called the queen, and I shall keep to the name, although I do not allow her voluntary influence or power. The non-breeders are what compose the hive, or what may be called the community at large; and the males are mere males: each of these parts of the community I shall hereafter consider separately. To take up the common bee in any one period of the year, or in other words, in any one month, and carry it round to the same, and observe what happens in that time, is probably including the whole ceconomy of bees; for although they may live more than one year, which I believe is not known, from its not being easily ascertained, yet each year can only be a repetition of the last, as I conceive they are complete in the first; therefore the history of one year may be said to make a whole, and of course it is not material at what time in the circle we begin the history. Perhaps the best time to begin the history of such insects as only come to full growth the season they are bred, and live through, the winter, and breed the summer following, is when they emerge from the torpid state, and begin to breed; but it might be thought that the common bee is an exception to this rule, because they begin early in the spring to breed, generally before they can be observed ; and as they breed to form a colony, which is to go offfrom the old stock, in order to set out anew, it might seem most natural to begin with this colony, and trace it through its various actions of life for one year, when it as it were regenerates itself, and comes round to the same point again that the old stock was in when it threw off this colony. Bees, like every other animal that is taken care of in the time of breeding or incubation, and nursed to the age of taking care of itself, cannot be said to have a period in which we can begin its natural history; but in some other insects there is such a period, for they can be traced from an egg, becoming totally independent of the parent from the moment of being laid, as the silk-worm, &c. 424 HUNTER ON THE ANIMAL CECONOMY.

There are three periods at which the history of the bee may commence: first, in the spring, when the queen begins to lay her eggs; in the summer, at the commencement of a new colony; or in the autumn, when they are going into winter-quarters. I shall begin the particular history of the bee with the new colony, when nothing is formed ; for it then begins everything that can possibly happen afterwards. When a hive sends off a colony it is commonly in the month of June; but that will vary according to the season, for in a mild spring bees sometimes swarm in the middle of May, and very often at the latter end of it. Before they come oft'they commonly hang about the mouth ofthe hole or door ofthe hive for some days, as if they had not sufficient room within for such hot weather, which I believe is very much the case; for if cold or wet weather come on, they stow themselves very well, and wait for fine weather. But swarming appears to be rather an operation arising from necessity, for they would seem not naturally to swarm, because if they have an empty space to fill, they do not swarm ; therefore by increasing the size of the hive, the swarming is prevented. This period is much longer in some than in others. For some evenings before they come oil, is often heard a singular noise, a kind of ring, or sound of a small trumpet; by comparing it with the notes ofthe pianoforte, it seemed to be the same sound with the lower A of the treble. The swarm commonly consists of three classes; a female, or females,* males, and those commonly called mules, which are supposed to be of no sex, and are the labourers; the whole about two quarts in bulk, making about six or seven thousand. It is a question that cannot easily be determined, whether this old stock sends off entirely young ofthe same season, and whether the whole of their young ones, or only part. As the males are entirely bred in the same season, part go off; but part must stay, and most probably it is so with the others. They commonly come off in the heat of the day, often immediately after a shower ; who takes the lead I do not know, but should suppose it was the queen. When one goes off they all immediately follow, and fly about seemingly in great confusion, although there is one principle actuating the whole. They soon appear to be directed to some fixed place, such as the branch of a tree or bush, the cavities of old trees, holes of houses leading into some hollow place; and whenever the stand is made, they all immediately repair to it, till they are all collected. But it would seem in some cases that they had not fixed upon any resting place before they came off, or if they had, that they were either disturbed, if it was near, or that it was at a great distance; for after hovering some time, as if undetermined, they fly away, mount up into the air, and go off with great velocity. When they have fixed upon their future habitation, they immediately begin to make their combs, for they have the materials within themselves. I have * I have reason to believe that never more than one female comes off with a swarm. OBSERVATIONS ON BEES. 425 reason to believe that they fill their crops with honey when they come away'; probably from the stock in the hive^ I killed several of those that came away, and found their crops full, while those that remained in the hive had their crops not near so full: some of them came away with farina on their legs, which I conceive to be rather accidental. I may just observe here, that a hive commonly sends off two, sometimes three swarms in a summer; but that the second is commonly less than the first, and the third less than the second ; and this last has seldom time to provide for the winter : they shall often threaten to swarm, but do not; whether the threatening is owing to too many bees, and their not swarming is owing to there being no queen, I do not know. It sometimes happens that the swarm shall go back again; but in such instances I have reason to think that they have lost their queen, for the hives to which their swarm have come back do not swarm the next warm day, but shall hang out for a fortnight or more, and then swarm; and when they do, the swarm is commonly much larger than before, which makes me suspect that they waited for the queen that was to have gone off with the next swarm. So far we have set the colony in motion. The materials of their dwelling, or comb, which is the wax, is the next consideration, with the mode of forming, preparing, or disposing of it. In giving a totally new account of the wax, I shall first show it can hardly be what it has been supposed to be. First I shall observe that, the materials, as they are found composing the comb, are not to be found in the same state (as a composition) in any vegetable, where they have been supposed to be got. The substance brought in on their legs, which is the farina of the flowers of plants, is, in common, I believe, imagined to be the materials of which the wax is made, for it is called by most the wax : but it is the farina, for it is always of the same colour as the farina of the flower where they are gathering; and indeed we see them gathering it, and we also see them covered almost all over with it, like a dust; nevertheless, it has been supposed to be the wax, or that the wax was extracted from it. Reaumur is of this opinion. I made several experiments to see if there was such a quantity of oil in it as would account for the quantity of wax to be formed, and to learn if it was composed of oil. I held it near the candle; it burnt, but did not smell like wax, and had the same smell when burning, as farina when it was burnt. I observed that this substance was of different colours on different bees, but always of the same colour on both legs of the same bee ;*

* [Aristotle, who describes many interesting particulars of the ceconomy of the bee, and knew something of the structure ofthe interior ofthe hive, was the first to observe that a bee in each single excursion from the hive always visits the same species of flower, and consequently comes home laden with pollen of the same colour. This has been confirmed by all subsequent observers, and, as we see, did not escape Mr. Hunter. The necessity for this instinct arises out of the operation which the pollen first undergoes ; the bee rakes out the pollen with incredible quickness by means of its first pair of legs, then passes it to the middle pair, which transfer it to the hind legs, by which it is wrought up into 426 HUNTER ON THE ANIMAL CECONOMY. whereas new-made comb was all of one colour. I observed that it was gathered with more avidity for old hives, where the comb is complete, than for those hives where it is only begun, which we ^ould hardly conceive if it was the materials of wax : also we may observe that at the very beginning of a hive, the bees seldom bring in any substance on their legs for two or three days, and after that the farina gatherers begin to increase; for now some cells are formed to hold it as a store, and some eggs are laid, which when hatched will require this substance as food, and which will be ready when the weather is wet. I have also observed, that when the weather has either been so cold, or so wet, in June, as to hinder a young swarm from going abroad, they have yet in that time formed as much new comb as they did in the same time when the weather was such as allowed them to go abroad. I have seen them bring it in about the latter end of March, and have observed in glass hives the bees with the farina on their legs, and have seen them disposing of it, as will be described hereafter. The wax is formed by the bees themselves ; it may be called an external secretion of oil, and I have found that it is formed between each scale ofthe under side ofthe belly.* When I first observed this substance, in my examination ofthe working bee, I was at a loss to say what it was : I asked myself if it was new scales forming, and whether they cast the old, as the lobster, &c, does? But«it was to be found only between the scales, on the lower side of the belly. On examining the bees through glass hives while they were climbing up the glass I could see that most of them had this substance, for it looked as if the lower or posterior edge of the scale was double, or that there were double scales; but I perceived it was loose, not attached. Finding that the substance brought in on their legs was farina, intended, as appeared from every circumstance, to be the food of the maggot, and not to make wax, and not having yet perceived anything that could give me the least idea of wax, I conceived these scales might be it, at least I thought it necessary to investigate them. I therefore took several on the point of a needle, and held them to a candle, where they melted, and immediately formed themselves into a round globe ; upon which I no longer doubted but this was the wax, which opinion was conlittle pellets. Now if the pollen were taken indiscriminately from different flowers, the difference in the size and shape ofthe pollen-grains would probably prevent them cohering together sufficiently to allow of the pellet being formed. Hence it is that in watching the return of bees to the hive some may be seen laden with yellow-coloured pellets, others with orange, pink, white, or greenishcoloured ones. The grains of pollen are not changed by the operation of kneading when detached from the peliet; under a miscroscope they are seen to possess their original figure.] * [Hunter first confirmed this statement by actual observation, but the merit ofthe discovery is entirely Hunter's. The only approach to it is in the observation by Morley, who says that he has taken bees with six pieces of wax within the plaits ofthe abdomen, three on each side (Female Monarchy, 1774), but without knowing the source of these pieces of wax.] . OBSERVATIONS ON BEES. 427 firmed to me by not finding those scales but in the building season. In the bottom of the hive we see a good many of the scales lying loose, some pretty perfect, others in pieces. I have endeavoured to catch them, either taking this matter out of themselves, from between the scales of the abdomen, or from one another, but never could satisfy myself in this respect: however I once caught a bee examining between the scales of the belly of another, but I could not find that it took anything from between. We very often see some of the bees wagging their belly, as if tickled, running round and to and fro for only a little way, followed by one or two other bees, as if examining them. I conceived they were probably shaking out the scales of wax, and that the others were ready upon the watch to catch them, but I could not absolutely determine what they did. It is with these scales that they form the cells called the comb, but perhaps not entirely, for I believe they mix farina with it; however, this only occasionally, when probably the secretion is not in great plenty. I have some reason to think that where no other substance is introduced the thickness of the scale is the same with that of the sides of the comb; if so, then a comb may be no more than a number of these united ; but a great deal of the comb seems to be too thick for this, and, indeed, would appear to be a mixture similar to the covering of the chrysalis. The wax naturally is white, but when melted from the comb at large it is yellow. I apprehended this might arise from its being stained with h»ney, the excrement ofthe maggots, and with the bee-bread. I steeped some white comb in honey, boiled some with farina as also with old comb, but I could not say that it was made yellower. Wax, by bleaching, is brought back to its natural colour, which is also a proof that its colour is derived from some mixture. I have reason to believe that they take the old comb, when either broken down, or by any accident rendered useless, and employ it again ; but this can only be with combs that have had no bees hatched in them, for the wax cannot be separated from the silk afterwards. Reaumur supposed that they new worked up the old materials, because he found the covering of the chrysalis of a yellower colour than the other parts ofthe new comb; but this is always so, whether they have old yellow comb to work up or not, as will be shown. The bees who gather the farina also form the wax, for I found it between their scales. The cells, or rather the congeries of cells, which compose the comb, may be said to form perpendicular plates or partitions, which extend from top to bottom of the cavity in which they build them, and from side to side. They always begin at the top or roof of the vault in which they build, and work downwards; but if the upper part of this vault, to which their combs are fixed, is removed, and a dome is put over, they begin at the upper edge of the old comb and work up into the new cavity at the top. They generally may be guided as to the direction of their new plates of comb, by forming ridges at top, to which they begin to attach their comb. In a 428 HUNTER ON THE ANIMAL CECONOMY.

long hive, if these ridges are longitudinal, their plates of comb will be longitudinal; if placed transverse, so will be the plates; and if oblique, the plates of comb will be oblique. Each plate consists of a double set of cells, whose bottoms form the partition between each set. The plates themselves are not very regularly arranged, not forming a regular plane where they might have done so; but are often adapted to the situation or shape of the cavity in which they are built. The bees do not endeavour to shape their cavity to their work, as the wasps do, nor are the cells of equal depths, also fitting them to their situation; but as the breeding cells must all be of a given depth, they reserve a sufficient number for breeding in, and they put the honey into the others, as also into the shallow ones. The attachment of the comb round the cavity is not continued, but interrupted so as to form passages; there are also passages in the middle of the plates, especially if there be a cross stick to support the comb; these allow of bees to go across from plate to plate. The substance which they use for attaching their combs to surrounding parts is not the same as the common wax ; it is softer and tougher, a good deal like the substance with which they cover in their chrysalis or the humble bee surrounds her eggs. It is probably a mixture of wax with farina. The cells are placed nearly horizontally, but not exactly so; the mouth raised a little, which probably may be to retain the honey the better; however, this rule is not strictly observed, for often they are horizontal, and towards the lower edge of a plane of comb they are often declining. The first combs that a hive forms are the smallest, and much neater than the last or lowermost. Their sides or partitions between cell and cell are much thinner, and the hexagon is much more perfect. The wax is purer, being probably little else but wax, and it is more brittle. The lower combs are considerably larger, and contain much more wax, or perhaps, more properly, more materials; and the cells are at such distances as to allow them to be of a round figure: the wax is softer, and there is something mixed with it. I have observed that the cells are not all of equal size, some being a degree larger than the others; and that the small are the first formed, and of course at the upper part where the bees begin, and the larger are nearer the lower part of the comb, or last made: however, in hives of particular construction, where the bees may begin to work at one end, and can work both down and towards the other end, we often find the larger cells both on the lower part of the combs and also at the opposite end. These are formed for the males to be bred in; and in the hornets' and wasps' combs there are larger cells for the queens to be bred in: these are also formed in the lower tier, and the last formed. The first comb made in a hive is all of one colour, viz., almost white; but it is not so white towards the end ofthe season, having then more of a yellow cast. OBSERVATIONS ON BEES. 429 Ofthe Royal Cell. There is a cell which is called the royal cell, often three or four of them, sometimes more; I have seen eleven, and even thirteen in the same hive; commonly they are placed on the edge of one or more of the combs, but often on the side of a comb; however, not in the centre along with the other cells, like a large one placed among the others, but often against the mouths of the cells, and projecting out beyond the common surface of the comb; but most of them are formed from the edge of the comb, which terminates in one of these cells. The royal cell is much wider than the others, but seldom so deep: its mouth is round, and appears to be the largest half of an oval in depth, and is declining downwards, instead of being horizontal or lateral. The materials of which it is composed are softer than common wax, rather like the last mentioned, or those of which ihe lower edge of the plate of comb is made, or with which the bees cover the chrysalis: they have very little wax in their composition, not one-third; the rest I conceive to be farina. This is supposed to be the cell in which the queen is bred, but I have reason to believe that this is only imagination: for, first, it is too large, and, moreover, seldom so deep as the large cells in which the males are bred; whereas, if proportioned to the length of the queen, it ought to be deeper, for length of body is her greatest difference. In the second place, its mouth is placed downwards ; and in the third place, it is never lined with the silken covering of the chrysalis, similar to the cells of the males and labourers; nor do we find excrement at the bottom of it. The number of these cells is very different in different hives. I think I have seen hives without any, and I have seen them with eleven or twelve, sometimes more. 1 have examined them at all times through the summer, but never found any alteration in them. The comb seems at first to be formed for propagation, and the reception of honey to be only a secondary use; for if the bees lose their queen they make no combs; and the wasp, hornet, &c, make combs, although they collect no honey ; and the humble bee collects honey, and deposits it in cells she never made. I shall not consider the bee as an excellent mathematician, capable of making exact forms, and having reasoned upon the best shape of the cell for capacity, so that the greatest number might be put into the smallest space (for the hornet and the wasp are much more correct, although not seemingly under the same necessity's they collect nothing to occupy their cells); because, although the bee is pretty perfect in these respects, yet it is very incorrect in others, in the formation of the comb: nor shall I consider these animals as forming comb of certain shape and size, from mere mechanical necessity, as from working round themselves; for such a mould would not form cells of diflerent sizes, much less could wasps be guided by the same principle, as their cells are of very 430 HUNTER ON THE ANIMAL CECONOMY.

different sizes, and the first by much too small for the queen wasp to have worked round herself: but I shall consider the whole as an instinctive principle, in which the animal has no power of variation or choice, but such as arises from what may be called external necessity. The cell has in common six sides, but this is most correct in those first formed ; and their bottom is commonly composed of those sides or planes, two of the sides making one; and they generally fall in between the bottoms of three cells of the opposite side ; but this is not regular, it is only to be found where there is no external interruption. I have already observed, that the last-formed cells in the season are not so well made ; that their partitions are thicker, and more of a yellow colour: this arises, I imagine, from the wax being less pure, having more alloy in it; and therefore, not being so strong, more of it is required. The bees would appear to reserve many of their cells for honey, and those are mostly at the upper part. In old hives, of several years' standing, I have found the upper part ofthe comb free from the consequences of having bred, such as the silk lining, and the excrement of the maggots at the bottom; while the lower part, for probably more than one-half of the plane of cells, showed strong marks of having contained many broods of young bees. In such the lining of silk is thick at the sides, composed of many laminas; and in many, the bottom is half filled up with excrement; and I observed at such parts, the comb was thickest at its mouth, which inclines me to think, that when a cell becomes shallow, by the bottom being in some degree filled up, the bees then add to its mouth. Such also they seem to reserve principally for the bee-bread; so that to lay up a greater store of honey is an object to them.

As soon as a few combs are formed, the female bee begins laying of eggs. As far as I have been able to observe, the queen is the only bee that propagates, although it is asserted that the labourers do. Her first eggs in the season are those which produce labourers; then the males, and probably the queen; this is the progress in the wasp, hornet, humble bee, &c. However, it is asserted by Riem, that when a hive is deprived of a queen, labourers lay eggs; also, that at this time, some honey and farina are brought in as store for a wet day. The eggs are laid at the bottom of the cell, and we find them there before the cells are half completed, so that propagation begins early and goes on along with the formation ofthe other cells. The egg is attached at one end to the bottom of the cell, sometimes standing perpendicularly, often obliquely; it has a glutinous or slimy covering, which makes it stick to anything it touches. It would appear that there was a period or periods for laying eggs; for I have observed in a new swarm that the great business of laying eggs did not last above a fortnight; although the OBSERVATIONS ON BEES. 431 hive was not half filled with comb, it began to slacken. Probably that end ofthe egg which is first protruded is that which sticks to the bottom of the cell; and probably the tail of the maggot is formed at that end: when they move the egg, how they make it stick again, I do not know. I have just observed, that they often move The egg out of a cell to some other, we may suppose; why they do this 1 cannot say; whether it is because we have been exposing this part, is not easily determined. In those new-formed combs, as also in many not half finished, we find the substance called bee-bread, and some of it is covered over with wax, which will be considered further. By the time they have worked above half way down the hive with the comb, they are beginning to form the larger cells, and by this lime the first broods are hatched, which were small or labourers; and now they begin to breed males, and probably a queen, for a new swarm ; because the males are now bred to impregnate the young queen for the present summer, as also for the next year. This progress in breeding is the same with that of the wasp, hornet, and humble bee.* Although this account is commonly allowed, yet writers on this subject have supposed another mode of producing a queen, when the hive is in possession of maggots, and deprived of their queen. What may be called the complete process of the egg, namely, from the time of laying to the birth of the bee, (that is, the time of hatching,) the life ofthe maggot, and the life of the chrysalis, is, I believe, shorter than in most insects. It is not easy to fix the time when the eggs hatch ; I have been led to imagine it was in five days. When they hatch, we find the young maggot lying coiled up in the bottom of the cell, in some degree surrounded with a transparent fluid. In many ofthe cells, where the eggs have just hatched, we find the skin standing in its place, either not yet removed, or not pressed down by the maggot. There is now an additional employment for the labourers, namely, the feeding and nursing the young maggots. We may suppose the queen has nothing to do with this, as there are at all times labourers enough in the hive for such purposes, especially loo as she never does bring the materials, as every other ofthe tribe is obliged to do at first; therefore she seems to be a queen by hereditary, or rather by natural right, while the humble bee, wTasp, hornet, &c, seem rather to work themselves into royalty, or mistresses of the community. The bees are readily detected feeding the young maggot; and indeed a young maggot might easily be brought up by any person who would be attentive to feed it. They open their two lateral pincers to receive the food, and swallow it. As they grow, they cast their coats or cuticles; but how often

* Reaumur on Bees says that the drone eggs, when laid in small cells, produce drones; and Wilhelmi says that it is the labourers only thai lay drone eggs. Mr. Riem says that queens are never reared in any but royal cells, although males sometimes in common cells ; and workers in old queen cells, but never iu those recently made. 432 HUNTER ON THE ANIMAL CECONOMY. they throw their coats, while in the maggot state, I do not know.* I observed that they often removed their eggs; I also find they very often shift the maggot into another cell, even when very large. The maggots grow larger and larger till they nearly fill the cell; and by this time they require no more food, and are ready to be inclosed for the chrysalis state: how this period is discovered I do not know, for in every other insect, as far as I am acquainted, it is an operation of the maggot or caterpillar itself; but in the common bee it is an operation ofthe perfect animal; probably it arises from the maggot refusing food. The time between their being hatched and their being inclosed is, I believe, four days; at least, from repeated observations, it comes nearly to that time. When ready for the chrysalis state, the bees cover over the mouth of the cell with a substance of a light brown colour, much in the same manner that they cover the honey, excepting that in the present instance the covering is convex externally, and appears not to be entirely wax, but a mixture of wax and farina. The maggot is now perfectly inclosed, and it begins to line the cell and covering of the mouth above-mentioned with a silk it spins out similar to the silkworm, and which makes a kind of pod for the chrysalis. Bonnet observed that in one instance the cell was too short for the chrysalis, and it broke its covering, and formed its pod higher or more convex than common: this I can conceive possible ; we often see it in the wasp. Having completed this lining, they cast off, or rather shove off from the head backwards, the last maggot coat, which is deposited at the bottom of the cell, and then they become chrysalises.

Of the Food of the Maggot, or what is commonly called Bee-Bread.

One would naturally suppose that the food of the maggot bee should be honey, both because it is the food of the old ones, and it is what they appear principally to collect for themselves ; however, the circumstance of honey being food for the old ones is no argument, because very few young animals live on the same food with the old, and therefore it is probable the maggot bee does not live upon honey; and if we reason from analogy, we shall be led to suppose the bee-bread to be the food of the maggot. It is the food of the maggot of the humble bee, who feeds upon honey, and even lays up a store of honey for a wet day, yet does not feed the young v/ith it. It is the food of the maggot of a black bee, and also of several others of the solitary kind who also feed upon honey; and wasps, &c, who do not bring in such materials, do not feed themselves upon honey. We cannot suppose that the bee-bread is for the food of the old bees, when we see them collecting it in the months of June and July, &c, at which time they have honey in

* [It has not yet been ascertained that the larva of the bee sheds its skin, as the lepidopterous caterpillars do, except when on the point of becoming a pupa, at which period a thin pellicle is also thrown out by each ofthe stigmata from the tracheal tubes.] OBSERVATIONS ON BEES. 433 great plenty; this substance is as common to a hive as any part belonging to the ceconomy of bees. Before they have formed five or six°square inches of comb in a young hive, we shall find eggs, honey, and bee-bread; and at whatever time of the year we kill a hive, we shall find this substance; and if a hive is short of honey and dies in the winter, we find no honey, but all the bee-bread, which was laid up in store for the maggots in the spring. They take great care of it, for it is often covered over with wax as the honey, and I believe more especially in the winter ; probably with a view to preserve it till wanted. In April I have found some of the cells full, others only half full. If we slit down a cell filled with this substance, we shall commonly find it composed of layers of different colours ; some a deep orange, others a pale brown. In glass hives we often find that the glass makes one side of the cell, and frequently in such we shall see at once the different strata above-mentioned. This is the substance which they bring in on their legs, and consists of the farina of plants. It is not the farina of every plant that the bee collects, at least they are found gathering it from some with great industry, while we never find them on others: St. John's wort is a favourite plant, but that comes late. The flower of the gourd, cucumber, &c, they seem to be fond of. What they do collect must be the very loose stuff, just ready to be blown off to impregnate the female part of the flower ; and to show that this is the case, we find bees impregnate flowers that have not the male part. It is in common of a yellow colour, but that of different shades, often of an orange; and when we see bees collecting it on bushes that have a great many flowers, so as to furnish a complete load, it is then ofthe colour of the farina of that bush. It is curious to see them deposite this substance in the cell. On viewing the hives, we often see bees with this substance on their legs, moving along on the combs, as if looking out for the cell to deposit it in. They will often walk over a cell that has some deposited in it, but shall leave that, and try another, and so on till they fix ; which made me conceive that each bee had its own cell. When they come to the intended cell, they put their two hind legs into it, with the two fore legs and the trunk out on the mouth of the neighbouring cell, and then the tail or belly is thrust down into the intended cell; they then bring the leg under the belly, and turning the point of the tail to the outside of the leg, where the farina is, they shove it off by the point ofthe tail. When it is thus shoved off both legs, the bee leaves it, and the two pieces of farina may be seen lying at the bottom ofthe cell; another bee comes almost immediately, and creeping into the cell, continues about five minutes, kneading and working it down into the bottom, or spreads it over what was deposited there before, leaving it a smooth surface. It is of a consistency like paste, burns slightly, and gives a kind of unusual smell, probably from having been mixed with animal juice in the act of kneading it down, for when brought in it is rather a powder than a paste. That it is the food of the maggot is 434 HUNTER ON THE ANIMAL CECONOMY. proved by examining the animal's stomach ; for when we kill a maggot full grown, we find its stomach full of a similar substance, only softer, as if mixed with a fluid, but we never find honey in the stomach ; therefore we are to suppose it is collected as food for the maggot, as much as honey is for the old bee. Mr. Schirach imagines that the semen of the male is the food of the maggot; but the food of the male and the queen maggot has been supposed to be different from that ofthe labourers. Reaumur says the food of the queen maggot is different in taste from that of the common ones. How he knew this, who was unacquainted with the food of thfi others, I cannot conceive.

Ofthe Excrement ofthe Maggot.

They have very little excrement, but what they do discharge is deposited at the bottom of the cell; and what at first will appear rather extraordinary, it is never cleared away by the bees, but allowed to dry along with the maggot coats; and both fresh eggs and honey are deposited in these cells so circumstanced, every future year ; so that in time the cells become nearly half full.

In this state they are forming themselves for a new life; they are either entirely new built, or wonderfully changed, for there is not the smallest vestige of the old form remaining; yet it must be the same materials, for now nothing is taken in. How far this change is only the old parts new modelled, or gradually altering their form, is not easily determined. To bring about the change, many parts must be removed out of which the new ones are probably formed.* As bees are not different in this state from the

* [It is in the determination of these interesting questions that the minute researches of Swammerdam manifest their importance. His figures demonstrate that the larva of the bee consists of thirteen annular segments, of which one corresponds to the head, three to the thorax, and nine to the abdomen of the perfect insect. The cephalic segment supports the rudimental eyes, which resemble the ocelli of other insects in structure, but are colourless and semitransparent. The antennae are represented by two small organs placed at the anterior angles ofthe head ; the oral organs are also indicated ; there is a small transverse upper lip or labrum, beneath which are two little horny parts, afterwards destined to become the mandibles: then "two little parts which seem as if they were articulated" these are subsequently developed into the maxillx ,■ and between these is a mesial "small, and somewhat prominent part, which resembles a trunk or tongue, and this increasing by degrees, at length indeed constitutes," says Swammerdam, "the trunk of the bee." We thus have evidence that the parts which so conspicuously distinguish the imago from the larva, and not "entirely new built," but are " wonderfully changed" by gradually altering their form and relative dimensions. With respect to the restof the larva, we find that the body is furnished on each side with ten minute circular spiracles, a pair being placed on each segment, with the exception of that which immediately follows the head, and the terminal one OBSERVATIONS ON BEES. 435 common flying insects in general, I shall not pursue the subject of their changes further; although it makes a very material part in the natural history of insects. When the chrysalis is formed into the complete bee, it then destroys the covering of its cell, and comes forth. The time it continues in this state is easier ascertained than either in that of the egg or the maggot; for the bees cannot move the chrysalis as they do the two others. In one instance it was thirteen days and twelve hours exactly; so that an egg in hatching being five days, the age ofthe maggot being four days, and the chrysalis continuing thirteen and a half, the whole makes twenty-two days and a half: but how far this is accurate I willnot pretend to say. I found that the chrysalis of a male was fourteen days, but this was probably accidental. When they first come out they are of a grayish colour, but soon turn brown. When the swarm of which I have hitherto been giving tfie history has come off early and is a large one, more especially if it was put into too small a hive, it often breeds too many for the hive to keep through the winter ; and in such case a new swarm is thrown off, which, however, is commonly not a large one, and generally has too little time to complete its comb, and store it with honey sufficient to preserve them through the winter. This is similar to the second or third swarm of the old hives.

Ofthe Seasons when the different operations of Bees take place.

I have already observed that the new colony immediately sets about the increase of their numbers, and everything relating to it. They had their apartments to build, both for the purpose of breeding, and as a storehouse for provisions for the winter. When the season for laying eggs is over, then is the season for collecting honey ; therefore when the last chrysalis for the season comes forth its cell is immediately filled with honey, and as soon as a cell is full it is covered over with pure wax, and is to be considered as store for the winter. This covering answers two very essential purposes: one is to keep it from spilling, or daubing the bees ; the other to prevent its evaporation, by which means it is kept fluid in such a warmth. They are also employed in laying up a store of bee-bread for the young maggots in the spring, for they begin to bring forth

which bears the arms. Previous to shedding the skin, the first three segments ofthe body begin te swell, and make room for the aggregated muscles which are to put in motion the locomotive organs, attached, in the perfect insect, exclusively to these segments. The larva being apodal, both the legs and wings may be regarded as beincr "entirely new built," and the pupa of the bee then presents an elegant disposition and well-ordered representation of all the limbs and parts of the future bee. The antennae and the tongue are seen lying along the breast, and the winas and legs bent from the sides of the thorax along the belly. Some of the segments of the larva are " removed," and out of these the organs of generation appear to be formed.] rr 436 HUNTER ON THE ANIMAL CECONOMY.

much earlier than probably any other insect, because they retain a summer heat and store up food for the young. In the month of August we may suppose the queen or queens are impregnated by the males ; and as the males do not provide for themselves, they become burdensome to the workers, and are therefore teazed to death much sooner than they otherwise would die; and when the bees set about this business of providing their winter store, every operation is over, except the collecting of honey and bee-bread. At this time it would seem as if the males were conscious of their danger, for they do not rest on the mouth of the hive in either going out or coming in, but hurry either in or out; however they are commonly attacked by one, two, or three at a time: they seem to make; no resistance, only getting away as fast as possible. The labourers do not sting them, only pinch them, and pull them about as if to wear them out; but I suspect it may be called as much a natural as a violent death. The whole ofthe males are now destroyed, and indeed it would have been useless to have saved any to impregnate the queen in the spring. That there may be many more than may be wanted I can easily believe, for this we see throughout nature; but she always times her operations well, although there may be supernumeraries. When the young are wholly come forth, and either the cells entirely filled, or no more honey to be collected, then is the time or season for remaining in their hives for the winter. Although I have now completed a hive, and no operations are going on in the winter months, yet the history of this hive is imperfect till it sends forth a new swarm. As the common bee is very susceptible of cold, we find as soon as the cold weather sets in they become very quiet or still, and remain so throughout the winter, living on the produce of the summer and autumn ; and indeed a cold day in the summer is sufficient to keep them at home more so than a shower in a warm day; and if the hive is thin and much exposed, they will hardly move in it, but get as close together as the comb will let them, into a cluster. In this manner they appear to live through the winter; however, in a fine day they become very lively and active, going abroad, and appearing to enjoy it, at which time they get rid of their excrement; for I fancy they seldom throw out their excrement when in the hive. To prove this, I confined some bees in a small hive, and fed them with honey for some days, and the moment I let them out they flew, and threw out their excrement in large quantities; and therefore in the winter, I presume, they retain the contents of their bowels for a considerable time. Indeed, when we consider their confinement in the winter, and that they have no place to deposit their excrement, we can hardly account for the whole of this operation in them. Their excrement is of a yellow colour, and according to their confinement it is found higher and higher up in the intestine, almost as high as the crop. Their life at this season of the year is more uniform, and may OBSERVATIONS ON BEES. 437 be termed simple existence, till the warm weather arrives again. As they now subsist on their summer's industry, they would seem to feed in proportion to the coldness ofthe season ; for from experiment I found the hive grow lighter in a cold week than it did in a warmer, which led to further experiments. I first made an experiment upon a bee-hive, to ascertain the quantity of honey lost through the winter. The hive was put into the scale November 3, 1776. oz. drams. November 10th, it had lost 2 7 17th,--------4 2i 24th,--------3 74 December 1st,-------8 2 8th, ------- 2 1 15th,--------5 2 22d,-------4 3 29th,--------5 4 1777. January 1st, -------- 2 5 12th,--------5 2 19th, -------- 3 4 26th,-------3 14 February 2d, ------- 5 0 9th, ------- 7 0 The whole 72 \h

Although an indolent state is very much the condition of bees through the winter, yet progress is making in the queen towards a summer increase. The eggs in the oviducts are beginning to swell, and I believe in the month of March she is ready to lay them, for the young bees are to swarm in June; which constitutes the queen bee to be the earliest breeder of any insect we know. In consequence of this, the labourers become sooner employed than any other of this tribe of insects. This both queen and labourers are enabled to accomplish, from living in society through the winter; and it becomes necessary in them, as they have their colony to form early in the summer, which is to provide for itself for the winter following. All this requires the process to be carried forward earlier than by any other insects, for these are only to have young which are to take care of themselves through the summer, not being under the necessity of providing for the winter. In the month of April I found in the cells young bees, in all stages, from the egg to the chrysalis state, some of which were changed in colour, therefore were nearly arrived at the fly state, and probably some might have flown. As this season is too early for collecting the provision of the maggot abroad, the store of farina comes now into use; but as soon as flowers begin to blow, the bees gather the fresh, although they have farina in store, giving the fresh the preference. 38* 438 HUNTER ON THE ANIMAL CECONOMY. Ofthe Queen.

The queen bee, as she is termed, has excited more curiosity than all the others, although much more belongs to the labourers. From the number of these, and from their exposing themselves, they have their history much better made out; but as there is only one queen, and she scarcely ever seen, it being only the effects of her labour we can come at, an opportunity has been given to the ingenuity of conjecture, and more has been said than can well be proved. She is allowed to be bred in the common way, only that there is a peculiar cell for her in her first stage; and Reaumur says, "her food is different when in the maggot state;" but as there is probably but one queen, that the whole might not depend on one life, it is asserted that the labourers have a power of forming a common maggot into a queen. If authors had given us this as an opinion only, we might have passed it over as improbable; but they have endeavoured to prove it by experiments, which require to be examined. And for that purpose I shall give what they say on that head, with my remarks upon it.

Abstracts from Mr. Schirach.

The following experiments were made to ascertain the origin of the queen bee:—"In twelve wooden boxes were placed twelve pieces of comb, four inches square, each containing both eggs and maggots, so suspended that the bees could come round every part ofthe comb: in each box was shut up a handful of working bees. Knowing that when bees are forming a queen they should be confined,* the boxes were kept shut for two days. When examined at the end of that period (six boxes only were opened), in all of them royal cells were begun, one, two, or three in each; all of these containing a maggot four days old. In four days, the other six boxes were opened, and royal cells found in each, containing maggots five days old, surrounded by a large provision of jelly; and one of these maggots examined in the mircroscope, in every respect resembled a working bee. " This experiment was repeated, and the maggots selected to be made queens were three days old ; and in seventeen days there were found in the twelve boxes fifteen lively, handsome queens.f These experiments were made in May, and the bees were allowed to work great part of the summer; "the bees were examined one

* How he came to know this I cannot conceive, for nothing a priori could <dve such information. t Now this account is not only improbable, but it does not tally with itself. First, it is not probable that a handful of bees should or would set about making two, three, or four queens, when we do not find that number in a lartre hive; and secondly, it seems inconsistent that only fifteen should be formed out of twelve parcels, when some ofthe former parcels had four youna queens. OBSERVATIONS ON BEES. 439 by one, but no drone could be discovered, and yet the queens were impregnated, and laid their eggs.* " The above experiment was repeated with pieces of comb containing eggs only, in six boxes, but no preparations were made towards producing a queen.f " The experiment of producing a queen bee from a maggot was repeated every month of the year, even in November.! "A maggot three days old was procured from a friend, inclosed in an ordinary cell, and shut up with a piece of comb, containing eggs and maggots. That three days old was formed into a queen, and all the other maggots and eggs were destroyed.^ " In above a hundred experiments a queen has been formed from maggots three days old."|| Wilhelmi observes that a queen cell, which is made while the bees are shut up, is formed by breaking down three common cells into one, when the maggot is placed in the centre, after which the sides arc repaired. A young queen lately hatched was put into a hive, which had been previously ascertained to contain no drones, and whose queen was removed ; and yet the young queen laid eggs.H In repeating Mr. Schirach's experiment, he shut up four pieces of comb, with one maggot in each; after two days the maggot were all dead, and the bees had desisted from labour.** A piece of comb from which all the eggs and maggots had been removed, was shut up with some honey and a certain number of workers: in a short time they became very busy, and upon the evening of the second day three hundred eggs were found in the cells.ft He repeated this experiment with the same result, and the bees were left to themselves; they placed queen maggots in the queen cells, newly constructed, and others in male cells; the rest

* Here is a wonder of another kind : queens laying eggs, which (we must suppose Mr. Schirack meant we should believe) they hatched, without the influence ofthe male. f Why eggs, which we must conceive hatched,and produced maggots, did not form queens, one cannot imagine. X In which month, as bees never swarm, there could be no occasion for mothers, or supernumerary queens, and still each experiment produced a handsome queen. This is as singular an observation as any. In this country, and in all similar ones, bees hardly breed after July, and by the beginning of September there is hardly a chrysalis to be seen ; yet these bred till November, and even laid eggs. § Why did the bees destroy them in this experiment, and not in others'? || The working bees from the above experiments are considered as all females, although the ovaria are too small for examination. It would appear that a maggot three days old was ofthe best age for this experiment, yet one should have conceived that a maggot two days old would soon befit. If There is no mystery in this; but did they hatch ? ** This is the most probable event in the whole experiments. ft This would show that labourers can be changed into queens at will, and that neither ihey nor their eggs require to be impregnated ; if this was the case, there would be no occasion for all the push in making a queen or a male. 440 HUNTER ON THE ANIMAL CECONOMY. were left undisturbed. He again took two pieces of comb which contained neither eggs nor maggots, and shut them up with a certain number of workers, and carried the box into a stove ; next evening, one of the pieces of comb contained several eggs, and the beginning of a royal cell that was empty. Besides the short observations contained in the notes, I beg leave to observe that I have my doubts respecting the whole of these experiments, from several circumstances which occurred in mine. The three following facts appear much against their probability; first, a summer's evening in this country is commonly too cold for so small a parcel of bees to be lively, so as to set about new operations; thev get so benumbed that they hardly recover in the day, and I should suspect that where these experiments were made (and indeed some are said to have been tried in this country), it is also too cold : secondly, if the weather should happen to be so warm as to prevent this effect, then they are so restless that they commonly destroy themselves; or wear themselves out; at least, after a few days' confinement we find them mostly dead : and thirdly, the account given ofthe formation of a royal cell, without mentioning the above inconvenience, which is natural to the experiment, makes me suspect the whole to be fabricated. To obviate the first objection which I found from experiment to prevent any success that otherwise might arise, I put my parcel of bees, with their comb, in which were eggs, as also maggots, and in some of the trials there were chrysalises,* into a warmer place, such as a glass frame over tan, the surface of which was covered with mould to prevent the rising of unwholesome air; but from knowing that, the maggot was fed with bee-bread, or farina, I took care to introduce a cell or two with this substance, as also the flowers of plants that produce a great deal of it, likewise some honey for the old ones. In this state my bees were preserved from the cold, as also provided with necessaries; but after being confined several days, upon opening the door of the hive, what were alive came to the door, walked and flew about, but grcdually left it, and on examining the combs, &c, I found the maggots dead, and nothing like any operation going on. The queen, the mother of all, in whatever way produced, is a true female, and different from both the labourers and the male. She is not so large in the trunk (abdomen) as the male, and appears to be rather larger in every part than the labourers. The scales on the under surface of the belly of the labourers, are not uniformly of the same colour over the whole scale ; that part being lighter which is overlapped by the terminating scale above, and the uncovered part

* I choose to have some chrysalises, for I supposed that if my bees died or flew away, the chrysalises when they came out, which would happen in a few days, not knowing where to go, might stay and take care of the maggots that might be hatched from the egg; but to my surprise, I found that neither the eggs hatched, nor did the chrysalises come forth; all died; from which I began to suspect that the presence ofthe bees was necessary for both. OBSERVATIONS ON BEES. 441 being darker ; this light part does not terminate in a straight line, but in two curves, making a peak, all which gives the belly a lighter colour in the neighbouring bees; more especially when it is pulled out or elongated. The tongue of the female is considerably shorter than that of the labouring bee, more like that of the male; however, the tongues of the labourers arc not in all of an equal length, but none have it so short as the queen. The size of the belly of the femalis of such animals varies a little, according to the condition they are in; but the belly of the male and the labourer has but little occasion to change its size, as they are at all times nearly in the same condition with regard to fat, having always plenty of provision ; but the true female varies very considerably; she is of a different size and shape in the summer to what she is in the winter; and in the winter she has what may be called her natural size and shape; she is upon the whole rather thicker than the labourer, and this thickness is also in the belly, which probably arises from the circumstance of the oviduct being in the winter pretty large, and the reservoir for semen full. The termination of the belly is rather more peaked than in the labourers, the last scale being rather narrow from side to side, and coming more to a point at the anus. The scales at this season are more overlapped, which can only be known by drawing them out. In the spring and summer she is more easily distinguished; the belly is not only thicker, but considerably longer than formerly, which arises from the increase of the eggs. We distinguish a queen from the working bee simply by size, and in some degree by colour; but this last is not so easily ascertained, because the difference in the colour is not so remarkable in the back, and the only view we can commonly get of her is on this part; but when a hive is killed, the best way is to collect all the bees, and spread them on white paper, or put them into water in a broad, flat-bottomed, shallow white-dish, in which they seem ; and by looking at them singly, she may be discovered. As the queen breeds the first year she is produced, and the oviducts never entirely subside, an old queen is probably thicker than a new-bred one, unless indeed the oviducts and the eggs form in the chrysalis state, as in the silk-worm, which I should suppose they did. The queen is perhaps at the smallest size just as she has done breeding, for as she is to lay eggs by the month of March, she must begin early to fill again ; but I believe her oviducts are never emptied, having at all times eggs in them, although but small. She has fat in her belly, similar to the other bees. It is most probable that the queen which goes off with the swarm is a young one, for the males go off with the swarm to impregnate her, as she must be impregnated the same year, because she breeds the same year. The queen has a sting similar to the working bee, 442 HUNTER ON THE ANIMAL CECONOMY. Of the Number of Queens in a Hive.

I believe a hive or swarm has but one queen, at least I have never found more than one in a swarm, or in an old hive in the winter; and probably this is what constitutes a hive ; for when there are two queens, it is likely that a division may begin to take place. Supernumerary queens are mentioned by Riem, who asserts he has seen them killed by the labourers, as well as the males. November 18th, 1788, I killed a hive that had not swarmed the summer before, and which was to appearance ready to swarm every day; but when I supposed the season for swarming was over, and it had not swarmed, I began to suspect that the reason why it did not was owing to there being no young queen or queens; and I found only one. This is a kind of presumptive proof that I was right in my conjecture ; unless it be supposed, that when they were determined not no swarm, they destroyed every queen except one. In a hive that died, I found no males, and only one queen. This circumstance, that so few queens are bred, must arise from the natural security the queen is in from the mode of their society; for although there is but one queen in a wasp's, hornet's, and humble bee's nest or hive, yet these breed a great number of queens; the wasp and hornet some hundreds; but not living in society during the winter, they are subject to great destruction, so that probably not one in a hundred lives to breed in the summer. I have said that the queen leaves off laying in the month of July; and now she is to be impregnated by the males before they die. Mr. Riem asserts, he has seen the copulation between the male and the female, but does not say at what season. I should doubt this; but Mr. Schirach supposes the queen impregnated without copulation. I know not whether he means by this that she is not impregnated at all, and supposes, like Mr. Debraw, that the eggs are impregnated after they are laid, by a set of small drones, who pass over the cells, and thrust their tails down into the cell, so as to besmear the egg.* Mr. Bonnet does not consider it necessaiy that the drones should be small for this purpose, for he saw a large drone passing over the cells of a piece of comb, stopping at every one which contained an egg, but at no other, and giving a knock with his tail on the mouth of the cell three times ; this he supposed was the mode of impregnating the eggs. The number three has always been a famous number; but it will not do where there are no males, which is the rase of a hive in the spring, the time when the queen is most employed in laying eggs; which made him suppose the use of the males was to feed the maggots with their semen. It is probable that the copulation is like that of most other insects. The copulation ofthe humble bee I have seen, it is similar to the common fly. The sting is extended at the time, and turned up on the back, be- * Mr. Debraw, knowing the drones died in the latter end of summer or the autumn, was obliged to suppose a small set of males, that lived through the winter, for that purpose. OBSERVATIONS ON BEES. 443 tween the two animals; they are some time in this act. In the hornet it is the same. The circumstances relative to the impregnating the queen not being known, great room has been given for conjecture, which, if authors had presented as conjectures only, it would have shown their candour; but they have given, what in them were probably conceits, as facts.

The male bee is considerably larger than the labourers: he is even larger than the queen, although not so long when she is in her full state with eggs: he is considerably thicker than.either, but not longer in the same proportion: he does not terminate at the anus in so sharp a point; and the opening between the two last scales of the back and belly is larger, and more under the belly than in the female. His proboscis is much shorter than that of the labouring bee, which makes me suspect he does not collect his own honey, but takes that which is brought home by the others; especially as we never find the males abroad on flowers, &c, only flying about the hives in hot weather, as if taking an airing; and when we find that the male ofthe humble bee, which collects its own food, has as long a proboscis or tongue as the female, I think it is from all these facts reasonable to suppose the male of the common bee feeds at home. He has no string. The males, I believe, are later in being bred than the labouring bee. As they are only produced to go off with a hive, they are not so early brought forth ; for in the month of April I killed a hive, in which I found maggots and chrysalises, but did not find any males among the latter : the maggots are too young for such investigation ; but about the 20th of May we observed males: they are all very much ofthe same size. In the month of August, probably about the latter end, we may suppose they impregnate the queen for the next year, and about the latter end of the same month, and beginning of September, they are dying, but seem to be hastened to their end by the labourers. In 1791, as early as the 19th of June, I saw the labourers killing the males of a hive, or rather of a swarm, that has not yet swarmed, but was hanging out; this, however, was out ofthe common course. They appear to be sensible of their fate, for they hurry in and out of the hive as quick as possible, seemingly with a view to avoid the labourers; and we find them attacked by the labourers, who pinch them with their forceps, and when they are so hurt, and fatigued with attempts to make their escape, as not to be able to fly, they are thrown over on the ground and left to die. That this is the fate of every male bee is easily ascertained, by examining every bee in the hive when killed for the honey, which is after this season ; no male being then found in it. Bonnet supposes them starved to death, as he never saw wounds on them. In the course of a winter I have killed several hives, some as late as April, and in such a way as to pre- 444 HUNTER ON THE ANIMAL CECONOMY. serve every bee, and after examining every one entirely, I never perceived one male of any kind ; although it has been asserted there arc two sizes of males, and that the small are preserved through the winter to impregnate the queen.

This class, for we cannot call it either sex or species, is the largest in number ofthe whole community; there are thousands of them to one queen, and probably some hundreds to each male, as we shall see by and by. It is to be supposed they are the only bees which construct the whole hive, and that the queen has no other business but to lay the eggs: they are the only bees that bring in materials; the only ones we observe busy abroad; and, indeed, the idea of any other is ridiculous, when we consider the disproportion in numbers as well as the employment of the others, while the working bee has nothing to take off its attention to the business of the family. They are smaller than either the queen or the males: not all of equal size, although the difference is not very great. The queen and the working bees are so much alike that the latter would seem to be females on a different scale: however, this difference is not so observable in the beginning of winter as in the spring, when the queen is full of eggs. They are all females in construction, having the female parts, which are extremely small, and would be easily overlooked by a person not very well acquainted with the parts in the queen: this has been observed by Mr. Riem ; indeed, one might suppose that they were only young queens, and that they became queens after a certain age; but this is not the case. They all have stings, which is another thing that makes them similar to the queen. From their being furnished with an instrument of defence and offence, they are endowed with such powers of mind as to use it, their minds being extremely irritable; so much so that they make an attack when not meddled with, simply upon suspicion, and when they do attack they always sting; and yet, from the circumstance of their not being able to disengage the sting, one should suppose they would be more cautious in striking with it. When they attack one another, they seldom use it, only their pincers: yet I saw two bees engaged, and one stung the other in the mouth, or thereabouts, and the sting was drawn from the body to which it belonged, and the one who was stung ran very quickly about with it; but I could not catch that bee to observe how the sting was situated. ' As they are the collectors of honey, much more than what is for their own use, either immediately or in future, their tongue is proportionably fitted for that purpose : it is considerably longer than that of either the queen or the male, which fits them to take up the honey from the hollow parts of flowers, of considerable depth. The mechanism is very curious, as will be explained further on. OBSERVATIONS ON BEES. 445 The number of labourers in a hive varies very considerably.

In one hive that I killed there were .... In another......... In one that died there were...... That I might guess at the number of bees from a given bulk, I counted what number an alehouse pint held, when wet, and found it contained ..... Therefore, as some swarms will fill two quarts, such must consist of near .......

Ofthe Parts concerned in the Nourishment ofthe Bee.

Animals which only swallow food for themselves, or whose alimentary organs are fitted wholly for their own nourishment, have them adapted to that use only; but in many, these organs are common for more purposes, as in the pigeon, and likewise in the bee. In this last, some of the parts are used as a temporary reservoir, holding both that which is for the immediate nourishment of the animal, and also that which is to be preserved for a future day, in the cells formerly described; this last portion is therefore thrown up again, or regurgitated. As it is the labourers alone in the common bee that are so employed, we might conceive this reservoir would belong only to them; but both the queen and males, both in the common and humble bee, have it, as also, I believe, every one of the bee tribe. As the bee is a remarkable instance of regurgitation, it is necessary the structure of the parts concerned in this operation, and which are also connected with digestion, should be well considered. Ruminating animals may be reckoned regurgitating animals, but in them it is for the purpose of digestion entirely in themselves. But many birds may be called regurgitating animals, and in them it is for the purpose of feeding their young. Crows fill their fauces, making a kind of craw, out of which they throw back the food when they feed their young; but the most remarkable is the dove tribe, who first fill their craw, and then throw it up into the beak of their young.* The bee has this power to a remarkable degree, not however for the purpose of feeding the young, but it is the mode of depositing their store in the cells when brought home. In none of the above-mentioned regurgitating animals are the reservoirs containing the food the immediate organ of digestion ; nor does the reservoir for the honey in the bee appear to be its stomach. The tonguef of the bee is the first of the alimentary organs to be

* See Observations on certain parts of the Animal CEconomy, p. 191 [p. 149 ofthe present edition]. t The part which Hunter so calls includes the maxillae and their rudimental palpi, the labium and its palpi, as well as the tongue properly so called, which seems, indeed, to be strictly an inordinate development of the labium, or lower 39 3338 4472 2432 2160

9000 44G HUNTER ON THE ANIMAL CECONOMY. considered: it is of a peculiar structure, and is probably the largest tongue of any animal we know,for its size. It may be said to consist of three parts respecting its length, having three articulations. One, its articulation with the head, which is in some measure similar to our larynx (mentum). Then comes the body of the tongue, which is composed of two parts; one, a kind of base (labium), on which the other, or true tongue (lingua), is articulated. The first part (labium) is principally a horny substance, in which there is a groove, and it is articulated with the first or larynx (mentum); on the end of this is fixed the true tongue, with its different parts. These two parts of the tongue are as it were inclosed laterally by two horny scales (maxillce), one on each side, which are concave on that side next to the tongue; one edge is thicker than the other, and they do not extend so far as the other parts. Each of these scales is composed of two parts, or scales, respecting its length, one articulated with the other: the first of those scales (cardo) is articulated with the common base, at the articulation of the first part of the tongue, and incloses laterally the second part of the tongue, coming as far forwards as the third articulation: on the end of this is articulated the second scale (lobus), which continues the hollow groove that incloses the tongue laterally; this terminates in a point. These scales have some hairs on their edge. On the termination of the second part is placed the true tongue, having two lateral portions or processes on each side, one within the other; the external (palpus labialis) is the largest, and is somewhat similar to the before-mentioned scales. This is composed of four parts, or rather of one large part, on which three smaller are articulated, having motion on themselves. The first, on which the others stand, is articulated at the edges of the tongue, on the basis or termination of the last-described part of the tongue; this has hairs on its edge. A little further forwards on the edges of the tongue are two small thin processes (paraglossa), so small as hardly to be seen with the naked eye. The middle part of all, of which these lateral parts are only appendages, is the true tongue (lingua). It is something longer than any of the before-mentioned lateral portions, and is not horny as the other parts are, but what may be called fleshy, being soft and pliable. It is composed of short sections, which probably are so many short muscles, as in fish, for they are capable of moving it in all directions. The tongue itself is extremely villous, having some very long villi at the point, which act, I conceive, somewhat like capillary tubes.* This whole apparatus can be folded up, into a very small cornlip ofthe ordinary trophi. I have inserted in the text the terms by which the different parts described by Hunter are known to entomologists.] * [Mr. Kirby observes, " The upper part of this tongue is cartilaginous, and remarkable for a number of transverse rings : below the middle it consists of a membrane, longitudinally folded in inaction, but capable of being distended to a considerable size. This membranous bag receives the honey, which the tongue, as it were, laps from the flowers, and conveys it to the pharynx. OBSERVATIONS ON BEES. 447 pass, under the head and neck. The larynx falls back into the neck, which brings the extreme end of the first portion of the tongue within the upper lip, or behind the two teeth; then the whole of the second part, which consists of five parts, is bent down upon and under this first part, and the two last scales are also bent down over the whole, so that the true tongue is inclosed laterally by the two second horny scales, and over the whole lie the two first. The oesophagus, in all this tribe of insects, begins just at the root of the tongue, as in other animals,* covered anteriorly by a horny scale, which terminates the head, and which may be called the upper lip or the roof of the mouth. It passes down through the neck and thorax, and when got into the abdomen it immediately dilates into a fine transparent bag, which is the immediate receiver of whatever is swallowed. From this the food (whatever it be) is either carried further on into the stomach to be digested, or is regurgitated for other purposes. To ascertain this in some degree in living bees, I caught them going out early in the morning, and found this bag quite empty: some time after I caught others returning home and found the bag quite full of honey, and some of it had got into the stomach. Now I suppose that which was in the craw was for the purpose of regurgitation, and as probably they had fasted during the night, part had gone on further for digestion. Whatever time the contents of this reservoir may be retained, we never find them altered, so as to give the idea of digestion having taken place: it is pure honey. From this bag the contents can be moved either way; either downwards to the stomach, for the immediate use ofthe animal itself, or back again, to be thrown out as store for future aliment. The stomach arises from the lower end and a little on the right side of this bag. It does not gradually contract into a stomach, nor is the outlet a passage directly out, but in the centre of a projection which enter some way into the reservoir, being rather an inverted pylorus, thickest at its most projecting part, with a very small opening in the centre, of a peculiar construction. This inward projecting part is easily seen through the coats of the reservoir, especially if full of honey. The stomach begins immediately on the outside ofthe reservoir, and the same part which projects into the reservoir is continued some way into the stomach, but appears to have no particular construction at this end, and therefore it is only fitted to prevent regurgitation into the re-

* This observation appears to have been overlooked by entomologists, who continued to believe that the opening of the pharynx was situated below the proboscis in bees, until the researches of Savigny on the oral organs of these insects and of the Lepidoptera were made public. Cuvier, in his Analyse des Travaux de la Classe des Sciences Mathematiques et Physiques de /' Institut, pendant V Annee 1814, observes, "On avait cru voir que l'ouverture du pharynx etait situee en dessous de cette trompe ou de cette levre, tandis que dans les masticateurs ordinaires elle Vest en dessous; mais c'etait une erreur; le pharynx est toujours sur la base de la trompe, et il y est meme garnis de parties interessantes a reoonnaitre et dont M. Savigny donne une description detaillee. " p. 25.] 448 HUNTER ON THE ANIMAL CECONOMY. servoir, as such would spoil the honey. This construction of parts is well adapted for the purpose, for the end projecting into the reservoir prevents any honey from getting into the stomach, because it acts there as a valve; therefore whatever is taken in must be by an action of this valvular part. The stomach has a good deal the appearance of a gut, especially as it seems to come out from a bag. It passes almost directly downwards in the middle ofthe abdomen. Its inner surface is very much increased, by having either circular valves, somewhat like the Valvulas conni ventes in the human jejunum, or spiral folds, as in the intestine ofthe shark, &c.; these may be seen through the external coats. In this part the food undergoes the change. Where the stomach terminates is not exactly to be ascertained,tbut it soon begins to throw itself into convolutions and becomes smaller. The intestine makes two or three twists upon itself, in which part it is enveloped in the ducts, constituting the liver and probably the pancreas, and at last passes on straight to the termination of the abdomen. Here it is capable of becoming very large, to serve upon occasion as a reservoir, containing a large quantity of excrement; it then contracts a little, and opens under the posterior edge of the last scale of the back, above the sting in the female and labourers, and the penis in the male.*

Bees certainly have the five senses. Sight none can doubt. Feeling they also have; and there is every reason for supposing they have likewise taste, smell, and hearing. Taste we cannot doubt; but of smell we may not have such proofs ; yet, from observation, I think they give strong signs of smell. When bees are hungry, as a young swarm in wet weather, and are in a glass hive, so that they can be examined, if we put some honey into the bottom it will immediately breed a commotion; they all seem to be upon the scent; even if they are weak and hardly able to crawl, they will throw out their proboscides as far as possible to get to it, although the light is very faint. This last appears to arise more from smell than seeing. If some bees are let loose in a bee-hive, and do not know from which house they came, they will take their stand upon the outside of some hive or hives, especially when the evening is coming on; whether this arises from the smell ofthe hives or sound I can hardly judge.

Bees may be said to have a voice. They are certainly capable of forming several sounds. They give a sound when flying, which they can vary according to circumstances. One accustomed to bees can immediately tell when a bee makes an attack by the sound.

* [See Preps. 476, 477, C01, 602, 603, 604, 605. Physiological Series, Hunterian Museum.] OBSERVATIONS ON BEES. 449 These are probably made by the wings. They may be seen standing at the door of their hive, with the belly" rather raised, and, moving their wings, making a noise. But they produce a noise independent of their wings ; for if a bee is smeared all over with honey, so as to make the wings stick together, it will be found to make a noise which is shrill and peevish. To ascertain this further, I held a bee by the legs with a pair of pincers, and observed it then made the peevish noise, although the wings were perfectly still: I then cut the wings off, and found it made the same noise. I examined it in water, but it then did not produce the noise till it was very much teased, and then it made the same kind of noise, and I could observe the water, or rather the surface of contact of the water, with the air at the mouth of an air-hole at the root of the wing, vibrating. I have observed that they, or some of them, make a noise the evenings before they swarm, which is a kind of ring, or sound of a small trumpet: by comparing it with the notes ofthe piano-forte, it seemed to be the same with the lower A of the treble. Of the Female Parts. I may here observe that insects differ from most of the classes of animals above them in having their eggs formed in the ducts along which they pass, not in a cluster on the back, as in some fish (for instance, all of the ray kind, or what are called the amphibia), in the bird, and as is supposed in the quadruped;* from thence the eggs are taken up, and by the ducts are carried along to their places of destination. Of the Oviducts. The female ofthe common bee, similar to all the females ofthe bee tribe, has six oviducts on each side, beginning by very small and almost imperceptible threads, as high as the chest; they then form one cord coiled up, or pass very serpentine, and become larger and larger as they approach the anus, owing to the gradual increased size of the eggs in them, which are now more distinct, and give the duct a sort of interrupted appearance toward the lower end. The six ducts, when full of eggs, make a kind of quadrangle, then all unite into one duct, which enters the duct common to it and the oviducts of the other side. The ducts common to the six oviducts on each side are extremely tender, so much so that it is difficult to save them. The duct common to those on both sides may be called the vagina, and it is continued to the anus or termination ofthe belly. Of the Male Parts. The male parts of generation in the common bee are much larger

* [This supposition, that the ova of the mammalia are formed in the ovaria, i.e. in a cluster attached to the dorsal aspect of the abdomen, and not in the ducts along which they pass, is now proved incontestably by the researches of V. Baer and other physiologists.] 39* 450 HUNTER ON THE ANIMAL CECONOMY. than in the humble bee. This wc suppose necessary, considering the vast number of eggs the common bee lays more than the humble bee does. The external parts of generation of the male bee are rather more under the belly than in the others of this tribe, not so much at the termination ofthe belly, and they are rather more exposed, the two last scales, especially the under one, not projecting so much ; the two holders are not so projecting beyond their base, nor are they so hooked or sharp as in the humble bee; hardly deserving the name of holders. From the external parts passes up into the abdomen a pretty large sheath, whose termination incloses the glans penis. It is a bulbous part, having a dark-coloured horny part upon it, which has two processes near its opening externally, one on each side, of a yellow colour ; it has another process, which is white, and seems to be a gland. It can be made to pass along this sheath or prepuce, and appear externally : I have been able, with a pair of forceps, to invert the sheath, beginning externally at the mouth, and pulling out a little at a time, by shifting my hold, till the glands has appeared externally. The internal parts are the testicles, with their appendages. The testicles are two small oblong bodies, lying near the back, having a vast number of air vessels, passing into them, and ramifying upon them. They are of a pale yellowish colour. From their lower ends pass down ducts, which may be called vasa deferentia, and which enter two bags : these two bags, into which the vasa deferentia enter, are probably reservoirs for the semen. From the union of these two bags passes out a duct, which runs towards the termination ofthe abdomen, and ends in the penis. These three parts, namely, testicles with their ducts, the two bags, and the duct arising from them, which I have termed urethra, are all folded on each other, so as to appear as one body. In the introduction to this account of bees I observed, that several things in their ceconomy might escape us if we considered them alone, but might be made out in other insects: an instance of this occurs in the impregnation of the female bee. The death of the males in the month of August, so that not one is left, and yet the queen to breed in the month of March, must puzzle any one not acquainted with the mode of impregnation of the females of most insects. Insects, respecting the males, are of two kinds: one, where the male lives through the winter, as well as the females; and the other, where every male of that species dies before the winter comes on ; among which may be considered, as a third, those where both male and female die the same year. Ofthe first, I shall only give the common fly as an instance ; of the second, I shall just mention all of the bee tribe; and the third maybe illustrated in the silk-worm moth. The mode of impregnation in the first is its being continued uninterruptedly through the whole period of laying eggs; while in the second, the copulation is in store; and in the third the female lays up, by the copulation, a store of semen, al- OBSERVATIONS ON BEES. 451 though the male is alive. Of this I shall now give an explanation in the silk-moth, which may be applied to the bee, and many other insects. In dissecting the female parts in the silk-moth, I discovered a bag lying on what may be called the vagina, or common oviduct, whose mouth or opening was external, but it had a canal of communication between it and the common oviduct. In dissecting these parts before copulation I found this bag empty, and when I dissected them after, I found it full. Suspecting this to contain the semen of the male, I immediately conceived the following experiment. I opened the female as soon as the male had united to her, and found the penis in the opening of this bag, and by opening the duct where the penis lay I observed the semen lying on the end of the penis. In another, I observed the bag to fill in the time of copulation; and in a pair that died in the act, I found the penis in this passage. When we consider the impregnation of the egg in the silk-worm, we may observe the following circumstances: First, many ofthe ova are completely formed, and covered with a hard shell, before copulation; secondly, the animals are a vast while in the act of copulation; and, thirdly, the bags at the anus are filled during the time of copulation. From the first observation it appears that the egg can receive the male influence through the hard or horny part of the shell. To know how far the whole, or only a part of the eggs, were impregnated by each copulation, I made the following experiments.* I took a female just emerged out of her cell, and put a male to her, and allowed them to be connected their full time. They were in copulation ten hours. I then put her into a box by herself, and when she laid her eggs, I numbered the different parcels as she laid them, viz., 1, 2, 3, 4, 5; these eggs I preserved, and in the summer following I perceived that the No. 5 was as prolific as the No. 1 ; so that this one copulation was capable of impregnating the whole brood ; and therefore the male influence must go either along the oviduct its whole length, and impregnate the incomplete eggs as well as the complete, which appears to be not likely, or those not yet formed were impregnated from the reservoir in the act of laying: for I conceived that these bags, by containing semen, had a power of impregnating the egg as it passed along to the anus, just as it traversed the mouth of the duct of communication. Finding that eggs completely formed could be impregnated by the semen, and also finding that the before-mentioned bag was a reservoir for the semen till wanted, I wished next to discover if they could be impregnated from the semen of this bag; but as this must be done without the act of copulation, I conceived it proper, first, to see whether the ova of insects might be impregnated without the natural act of copulation, by applying the male semen over the ova, * All these experiments on the silk-moth were begun in the summer 1767, and repeated by Mr. Bell in the year 1770. 4.V2 HUNTER ON THE ANIMAL CECONOMY. just as they were laid. The following experiments were made on the silk-moth. Experiment I. I took a female moth, as soon as she escaped from her pod, and kept her carefully by herself upon a clean card, till she be*an to lay ; then I took males that were ready for copulation, opened them, exposing their seminal ducts, and after cutting into these, collected their semen with a hair pencil: with this semen I covered the ova, as soon as they passed out of the vagina. The card with these eggs, having a written account ofthe experiment upon it, I kept in a box by itself. In the ensuing season eight of the ova hatched at the same time with others naturally impregnated. Thus then I ascertained that the eggs could be impregnated by art, after they were laid.* The ova laid by females that had not been impregnated did not stick where they were laid ; so that the semen would appear not only to impregnate the ova, but also to be the means of attaching them. . To know whether that bag in the female silk-moth which increased at the time of copulation, was filled with the semen of the male, I made the following experiment. Experiment II. I took a female moth, as soon as she had escaped from the pod, and kept her on a card till she began to lay. I then took females that were fully impregnated before they began to lay, and dissected out that bag which I supposed to be the receptacle for the male semen ; and wetting a camel-hair pencil with this matter, covered the ova as soon as they passed out of the vagina. These ova were laid carefully on the clean card, and kept till the ensuing season, when they all hatched at the same time with those naturally impregnated. This proves that this bag is the receptacle for the semen, and gradually decreases as the eggs are laid.

I have observed that it is only the queen and the labourers that have stings ; and this provision of a sting is perhaps as curious a circumstance as any attending the bee, and probably is one ofthe characters of the bee tribe. The apparatus itself is of a very curious construction, fitted for inflicting a wound, and at the same time conveying a poison into that wound. The apparatus consists of two piercers, conducted in a groove, or director, which appears to be itself the sting. This groove is somewhat thick at its base, but terminates in a point; it is articulated to the last scale of the upper side of the abdomen by thirteen thin scales, six on each side, and one behind the rectum. These scales inclose, as it were, the rectum or anus all round; they can hardly be said to be articulated to each other, only at- * [This circumstance was proved, as regards the ova of fishes, by Gleditsch. See Memoires de l'Acad. de Berlh), 1764.] OBSERVATIONS ON BEES. 453 tached by thin membranes, which allow of a variety of motions; three of them, however, are attached more closely to a round and curved process, which comes from the basis ofthe groove in which the sting lies, as also to the curved arms ofthe sting, which spread out externally. The two stings may be said to begin by those two curved processes at their union with the scales, and converging towards the groove at its base, which they enter, then pass along it to its point. They are serrated on their outer edges, near to the point. These two strings can be thrust out beyond the groove although not far, and they can be drawn within it; and, I believe, can be moved singly. All these parts are moved by muscles, which we may suppose are very strong in them, much stronger than in other animals ; and these muscles give motion in almost all directions, but more particularly outwards. It is wonderful how deep they will pierce solid bodies with the sting. I have examined the length they have pierced the palm of the hand, which is covered with a thick cuticle : it has often been about the Tyh of an inch. To perform this by mere force two things are necessary, power of muscles and strength of the sting, neither of which they seem to possess in sufficient degree. I own I do not understand this operation. I am apt to conceive there is something in it distinct from simple force applied to one end of a body ; for if this was simply the case, the sting of the bee could not be made to pierce by any power applied to its base, as the least pressure bends it in any direction ; it is possible the serrated edges may assist by cutting their way in, like a saw. The apparatus for the poison consists of two small ducts, which are the glands that secrete the poison : these two lie in the abdomen, among the air-cells, &c.: they both unite into one, which soon enters into, or forms, an oblong bag, like a bladder of urine; at the opposite end of which passes out a duct, which runs towards the angle where the two stings meet; and entering between the two stings, is continued between them in a groove, which forms a canal by the union ofthe two stings to this point. There is another duct on the right of that described above, which is not so circumscribed, and contains a thicker matter, which, as far as I have been able to judge, enters along with the other: but it is the first that contains the poison, which is a thin, clear fluid. To ascertain which was the poison, I dipped points of needles into both, and pricked the back of the hand : and those punctures that had the fluid from the firstdescribed bags in them grew sore and inflamed, while the others did not. From the stings having serrated edges, it is seldom the bees can disengage them; and they immediately upon stinging endeavour to make their escape, but are generally prevented, as it were caught in their own trap; and the force they use commonly drags out the whole of the apparatus for stinging, and also part of the bowels; so that the bee most frequently falls a sacrifice immediately upon having effected its purpose. Upon a superficial view one conceives that the first intention of the bee having a stino- is 454 HUNTER ON THE ANIMAL CECONOMY. evident; one sees it has property to defend, and that therefore it is fitted for defence : but why it should naturally fall a sacrifice in its own defence, does not so readily appear: besides, all bees have stings, although all bees have not property to defend, and therefore are not under the same necessity of being so provided. Probably its having a sting to use was sufficient for nature to defend the bee without using it liberally ; and the loss of a bee or two, when they did sting, was of no consequence: for it is seldom that more die. I have now carried the operations of a hive, or the ceconomy of the bee, completely round the year ; in which time they revolve to the first point we'set out at, and the continuance is only a repetition ofthe same revolutions as I have now described: but those revolutions occasion a series of effects in the comb, which effects in time produce variations in the life of the hive. Besides, there are observations that have little to do with the ceconomy of a year, but include the whole ofthe life of this insect, or at least its hive.

I have observed that the life of the male is only one summer, or rather a month or two; and this we know from there being none in the winter, otherwise their age could not be ascertained, as it is impossible to learn the age of either the queen or labourers. Some suppose that it is the young bees which swarm ; and most probably it is so : but I think it is probable also, that a certain number of young ones may be retained to keep up the stock, as we must suppose that many ofthe old ones are, from accidents of various kinds, lost to the hive; and we could conceive, that a hive three or four years old might not have an original bee in it, although a bee might live twice that time. But there must be a period for a bee to live ; and if I were to judge from analogy, I should say that a bee's natural life is limited to a certain number of seasons; viz., one bee does not live one year, another two, another three, &c. I even conceive that no individual insect of any species lives one month longer than the others of the same species. I believe this is the case with all insects ; but the age of either a labourer or a queen may never be discovered. One might suppose that the life of a bee, and the time a hive can possibly last, would be nearly equal: although this is not absolutely necessary, because they can produce a succession, which they probably do; fori am very ready to imagine, that after the first brood in the season, all the last winter bees die, and the hive is occupied with the first brood ; and that they breed the first swarm, or that the old breed the whole of this season's breeding, and then die, and those that continue through the winter are the young, and if so, then they follow the same course with their progenitors. The comb of a hive may be said to be the furniture and storehouse ofthe bees, which by use wear out; and from the description I have given, it will appear that the comb in time will be rendered unfit for use. I observed that they did not clean out the OBSERVATIONS ON BEES. 455 excrement of the maggot, and that the maggot, before it moved into the chrysalis state, lined the cell with a silk, similar to many other insects. It lines the whole cell, top, sides, and bottom ; the two last are permanent; and at the bottom it covers with this lining its own excrement.* Why the bee maggot is formed to do this is probably because honey afterwards is to be put into the cell; so that the honey is laid into this last silken bag. How often they may breed in the same cell I do not know, but I have known them three times in the same season; each time the excrement has been accumulating, and the cell has been lined three times with silk. From this account we must see that a cell in time will be so far filled up as to render it unfit for breeding. On separating the lining of silk, which is easiest done at the bottom, on account of the dried excrement between each lining, I have counted above twenty different linings in one cell, and found the cell about one-quarter, or one-third filled up ; when such a cell, or a piece of comb with such cells, is steeped in water, so as to soften the excrement between the linings, they are separated from each other at the bottom by the swelling of the excrement, so that they can be easily counted. A piece of comb so circumstanced, when boiled for the wax, will keep its form, and the small quantity of wax is squeezed out of different parts as if squeezed out of a sponge, and runs together into the crevices ; while a piece of comb, that never has been bred in, even of the same hive, melts almost wholly down. It is this wax that has the fine yellow, while the other of the same hives, although brown, yet shall be white when melted; so that I was led to imagine the wax took its tinge from the farina, excrement, &c, but upon boiling pure wax with such materials it was not tinged with this transparent yellow, only became dirty. In some of those cells that had probably been bred in twenty times or more, when soaked so as to make the excrement swell, I have seen the bottom of the last lining rise even with the mouth, or top of the cell, so that the cavity of the cell was now full: in others, I have seen it rise higher than the mouth, so that the last-formed layers were almost inverted, and turned inside out. A piece of such comb, consisting of two rows of cells, is to be considered as a mould, and the lining of silk and the excrement as the cast; when this is boiled, so as either to extract all the wax or mould, or to destroy its original regular formation which constituted the comb, and nothing is left but the cells of silk, &c, they all easily separate from each other, being only so many casts, with the mould destroyed; and the bottoms, which were indented into each other, are very perfect. From the above account we must see that the combs of a hive can only last a certain number of years ; however, to make them last longer, the bees often add a-little to the mouth of the cell, which is seldom done with wax alone, but with a mixture; and they sometimes cover the silk lining of the last chrysalis ; but all this makes such cells clumsy, in comparison to the original ones. * This neither the wasp nor the hornet do, although ihey do not clean out the excrement of their maggots. 456 HUNTER ON THE ANIMAL CECONOMY. 40. ANATOMICAL REMARKS ON A NEW MARINE ANIMAL.*

Animals which come from foreign conntries, and cannot be brought to England alive, must be kept in spirits to preserve them from°putrefaction, which makes them less fitted for anatomical examination; for the spirits which preserve them produce a change in many of their properties, and alter the natural colours and texture of their parts, so that often the structure alone of the animal can be ascertained; and where this is not naturally distinct it becomes frequently entirely obscured, and the texture of the finer parts is wholly destroyed, requiring a very extensive knowledge of such parts in animals at large, to assist us in bringing them to light; this happens to be the case with the animal whose dissection is the subject of this postscript. The animal may be said to consist of a fleshy covering, a stomach and intestinal canal, and the two cones with their tentacula and moveable shell, which last may be considered as appendages. The body ofthe animal is flattened, and terminates in two edges, which are intersected by rugas, the fasciculi of transverse muscular fibres which run across the back being continued over them. Upon each of these edges is placed a row of fine hairs, which project to some distance from the skin. The fleshy covering consists principally of muscular fibres: those upon the back are placed transversely, to contract the body laterally ; those on the belly longitudinally, to shorten the animal when stretched out, and to draw it into the shell. The stomach and intestine make one straight canal: the anterior end of this forms the mouth, which opens into the grooves made by the spiral turns of the tentacula round the stem of each of the cones; and the intestine at the posterior end opens externally, forming the anus. From the contracted state of the animal the intestine is thrown into a number of folds. On examining the cones and the tentacula I at first believed that the spiral form arose from their being in a contracted state; and that when the tentacula were erected the cone untwisted, forming a longer cone with the tentacula arising from its sides, like the plume

* [This animal was sent to Mr. Hunter from Barbadoesby Sir Everard (then Mr.) Home, who described it in the Philosophical Transactions for 1784 as a species of Actinia, and the anatomical remarks in the text from the postscript to that Paper. The same species had been, however, previously described and figured by Pallas in the Miscellanea Zoologica, p. 139, tab. x. fig. 2—10, (1766,) and had been more correctly referred by that distinguished naturalist to the genus Serpula, under the name of Serpula gigantea. It still retains this denomination, and is placed among the tubicular Anellides in the latest edition of the Regne Animal of Cuvier.] ANATOMICAL REMARKS, ETC. 457 from the stem of a feather; and that this stem was drawn in or shortened by means of a muscle passing along the centre, which threw the tentacula into a spiral line, similar to the penises of many birds; but how far this is really the case I have not been able to ascertain. The internal structure of this animal, like most of those which have tentacula, is very simple ; it differs, however, materially from many, in having an anus, most animals of this tribe, as the polypi, having only one opening, by which the food is received, and the excrementitious part of it also afterwards thrown out.* This we might have supposed, from analogy, to take place in the animal which is here described, more particularly since it is inclosed in a hard shell, at the bottom of which there appears to be no outlet; but as there is an anus this cannot be the case. It is very singular that in the leech,f polypi, &c, where no apparent inconvenience can arise from having an anus, there is not one; while in this animal, where it would seem to be attended with many, we find one ; but there being no anus in the polypi, &c, may depend upon some circumstance in the animal ceconomy which we are at present not fully acquainted with. The univalves, whose bodies are under similar circumstances respecting the shell with this animal, have the intestine reflected back, and the anus by that means brought near to the external opening of the shell, the more readily to discharge the excrement; and although this structure in these animals appears to be solely intended to answer that purpose, yet when we find the same structure in the black snail, which has no shell, this reasoning will not wholly apply, and we must refer it to some other intention in the animal ceconomy.J In this animal we must therefore rest satisfied that the disadvantageous situation of the anus, with respect to the excrement's being discharged from the shell, answers some purpose in the ceconomy ofthe animal which more than counterbalances the inconveniences produced by it. It would appear, from considering all the circumstances, that the excrement thrown out at the anus must pass from the tail along the inside of the tube, between it and the body of the animal, till it comes to the external opening of the shell, as there is no other evident mode of discharging it. How the tube or shell is formed in stone or coral is not easily ascertained. It may be asked whether this animal has the power of boring backwards, as the Teredo navalis probably does, or

* [This is not the case with those Polypi which have the tentacula beset with vibratile cilia, as the Flustrx, Escharx, Vescularix, &c, as in these there is a reflected intestinal canal, terminating by a distinct anus, opening near the mouth.] t [In the leech the alimentary canal terminates by a minute anus, situated above the caudal sucker.] X [The reflected disposition of the intestinal canal is, in a greater or less degree, common to all molluscous animals, and the anus is thus brought into communication with the respiratory cavity.] 40 ■158 HUNTER ON THE ANIMAL CECONOMY. whether the stone or coral is formed at the same time with the animal, and grows and increases with it ; and if we consider all the circumstances, this last would appear to be most probable, and agree best with the different phasnomena; for the coral is lined with a shell, which could not be the case if the animal was continually increasing this hole, both in length and breadth, in proportion to its growth; but if the coral and the animal increase together, it is then similar to the growth of all shells, whether bivalve or univalve. The animal does not appear to have the power of increasing its canal, being only composed of soft parts. This, however is no argument against its doing it, for every shell-fish has the power of removing a part of its shell, so as to adapt the new and the old together, which is not done by any mechanical power, but by absorption.* The tribe of animals which have tentacula consists of an almost infinite variety, and many of the species have been described. Of that kind, however, which has the double cones, I believe hitherto no account has been given. It is most probably to be found in the seas surrounding the different islands in the West Indies, for I received an animal some years ago from Mr. Oliver, surgeon, at Tenby in Pembrokeshire, which he had procured from a gentleman at St. Vincent's, which, upon examination, proves to be the same animal with that above described, only that the moveable shell is wanting. Since I began this Postscript I find there is a description of a double-coned Terebella, published by the Rev. Mr. Cordiner, at Banff in Scotland, which was found upon that coast, in which the cones have their tentacula passing out from the end, and when erected they spread from the cone as from a centre. This proves that the animals with double-coned tentacula also have different species.

* [This is best illustrated in the thinning of the septa between the different whorls of the cones and olives. If the margins of these septa be examined with a pocket lens, after a section ofthe shell has been made, it will be found that two out ofthe three layers of which they were originally composed have been removed. The absorption of shell is also illustrated in the removal or the smoothing down of the spines of the Murices,- in the flattening of the inner lip of the mouth of the Purpuras,- in the widening of the fsecal aperture of the Fissurellx, &c, &c. These instances were doubtless well known to Hunter; but the doctrine of the absorption of shell has been lately adduced as a new discovery, in a recent volume of the Philosophical Transactions. See Mr. J. E. Gray " On the Power possessed by Mollusca of dissolving Shells." Phil. Trans. 1833, p. 796.] B OBSERVATIONS ON SOME FOSSIL BONES. 459 41. OBSERVATIONS ON THE FOSSIL BONES PRESENT- ED TO THE ROYAL SOCIETY BY HIS MOST SERENE HIGHNESS THE MARGRAVE OF ANSPACH, ETC.

BY THE LATE JOHN HUNTER, ESQ., F.R.S.

[Communicated by Everard Home, Esq., F.R.S.*]

The bones which are the subject of the present paperare to be considered more in the light of incrusted bodies than extraneous fossils,

* [From the Philosophical Transactions, vol. lxxxiv.; read May 8th, 1794. The following description, by the Margrave of Anspach, of the caves from which the fossils described in the text were taken, precedes the original memoir. "A ridge of primaeval mountains runs almost through Germany, in a direction nearly from west to east; the Hartz, the mountains of Thuringia, the Fichtelberg in Franconia, are diflerent parls of it, which in their further extent constitute the Riesenberg, and join the Carpathian mountains. The highest part of this ridge are granite, and are flanked by alluvial and stratified mountains, consists chiefly of limestone, marl, and sandstone; such at least is the tract of hills in which the caves to be spoken of are situated; and over these hills the main road leads from Bayruth to Erlang, or Nurenberg. Half-way to this town lies Streitburg, where there is a post, and but three or four English miles distant from thence are the caves mentioned, near Gailenreuth and Klausstein, two small villages, insignificant in themselves, but become famous for the discoveries made in their neighbourhood. "The tract of hills is there broken off by many small and narrow valleys, confined mostly by steep and high rocks, here and there overhanging, and threatening, as it were, to fall and crush all beneath; and everywhere thereabouts are to be met with objects which suggest the idea of their being evident vestiges of some general and mighty catastrophe which happened in the primaeval times of the globe. " The strata of these hills consist chiefly of limestone of various colour and texture, or of marl and sandstones. The tract of limestone hills abounds with petrifactions of various kinds. "The main entrance to the caves at Gailenreuth opens near the summit of a limestone hill towards the east. An arch, near seven feet high, leads into a kind of ante-chamber, eighty feet in length, and three hundred feet in circumference, which constitutes the vestibule of four other caves. This ante-chamber is lofty and airy, but has no light except what enters by its open arch; its bottom is level, and covered with black mould, although the common soil ofthe environs is loam and marl. " By several circumstances, it appears that it has been made use of in turbulent times as a place of refuge. " From this vestibule, or first cave, a dark and narrow alley opens in the corner at the south end, and leads into the second cave, which is about sixty feet long, eighteen high, and forty broad. Its sides and roofs are covered, in a wild and rough manner, with stalactites, columns of which are hanging from the roof, others rising from the bottom, meeting the first in many whimsical shapes. " The air of this cave, as well as of all the rest, is always cool, and has, even in the height of summer, been found below temperate. Caution is therefore necessary to its visiters; for it is remarkable that people, having spent any time in this or the other caverns, always on their coming out again appear pale, which in part may be owing to the coolness ofthe air, and in part likewise to the particular exhalations within the caves. A very narrow, winding, and troublesome passage opens further into a "Third cave or chamber, of a roundish form, and about thirty feet diameter 160 HUNTER ON THE ANIMAL CECONOMY. since their external surface has only acquired a covering of crystallized earth, and little or no change has taken place in their internal structure.

covered all over with stalactites. Very near its entrance there is a perpendicular descent of about twenty feet, into a dark and frightful abyss ; a ladder must be brought to descend into it, and caution is necessary in using it, on account of the rough and slippery stalactites. When you are down, you enter into a gloomy cave of about fifteen feet diameter and thirty feet high, making properly but a segment of the third cave. " In the passage to this third cave, some teeth and fragments of bones are found ; but coming down to the pit of the cave, you are every way surrounded by a vast heap of animal remains. The bottom of this cave .is paved with a stalactical crust of near a foot in thickness ; large and small fragments of all sorts of bones are scattered everywhere on the surface of the ground, or easily drawn out ofthe mouldering rubbish. The very walls seem filled with various and innumerable teeth and broken bones. The stalactical covering ofthe uneven sides ofthe cave does not reach quite down to its bottom, whereby it plainly appears that this vast collection of animal rubbish some time ago filled a higher space in the cave, before the bulk of it sunk by mouldering. "This place is in appearance very like a large quarry of sandstones ; and indeed the largest and finest blocks of osteolithical concretes might be hewn out in any number, if there was but room enough to come to them, and to carry them out. This bony rock has been dug into in different places, and everywhere undoubted proofs have been met with, that its bed, or this osteolithical stratum, extends every way far beneath and through the limestone rock into which and through which these caverns have been made ; so that the queries suggesting themselves about the astonishing numbers of animals buried here confound all speculation. "Along the sides of this third cavern there are some narrower openings, leading into different smaller chambers, of which it cannot be said how deep they go. In some of them bones of smaller animals have been found, such as jaw-bones, vertebrae, and tibiae, in large heaps. The bottom of this cave slopes toward a passage seven feet high, and about as wide, being the entrance lo a " Fourth cave, twenty feet high and fifteen wide, lined all round with a stalactical crust, and gradually sloping to another deep descent, where the ladder is wanted a second time, and must be used with caution as before, in order to get into a cave forty feet high and about half as wide. In those deep and spacious hollows, worked out through the most solid mass of rock, you again perceive with astonishment immense numbers of bony fragments of all kinds and sizes, sticking everywhere in the sides of the cave, or lying on the bottom. This cave also is surrounded by several smaller ones ; in one of them rises a stalactite of uncommon bigness, being four feet high and eight feet diameter, in the form of a truncated cone. In another of those side grottos, a very neat stalactical pillar presents itself, five feet in height, and eight inches in diameter. "The bottom of all these grottos is covered with true animal mould, out of which may be drug fragments of bones. "Besides the smaller hollows, spoken of before, round this fourth cave, a very narrow opening has been discovered in one of its corners. It is of very difficult access, as it can be entered only in a crawling posture. This dismal and dangerous passage leads into a fifth cave, of near thirty feet high, forty-three long, and of unequal breadth. To the depth of six feet this cave has been dug, and nothing has been found but fragments of bones and animal mould. The sides are finely decorated with stalactites of different forms and colours ; but even this stalactical crust is filled with fragments of bones sticking in it, up to the very roof. "From this remarkable cave another very low and narrow avenue leads into the last discovered, or the " Sixth cave, not very large, and merely covered with a stalactical crust, OBSERVATIONS ON SOME FOSSIL BONES. 461 The earths with which bones are most commonly incrusted are the calcareous, argillaceous, and siliceous, but principally the calcareous; and this happens in two ways: one, the bones being immersed in water in which this earth is suspended ; the other, water passing through masses of this earth, which it dissolves, and afterwards deposits upon bones which lie underneath. Bones which are incrusted seem never to undergo this change in the earth, or under the water, where the soft parts were destroyed; while bones that are fossilized become so in the medium in which they were deposited* at the animal's death. The incrusted bones have been previously exposed to the open air: this is evidently the case with the bones at present under consideration, those of the rock of Gibraltar, and those found in Dalmatia; and, from the account given by the Abbe Spallanzani, those of the island of Cerigo are under the same circumstances. They have the characters of exposed bones, and many of them are cracked in a number of places, particularly the cylindrical bones, similar to the effects of long exposure to the sun. This circumstance appears to distinguish them from fossilized bones, and gives us some information respecting their history. If their numbers had corresponded with what we meet with of recent bones, we might have been led to some opinion of their mode of accumulation; but the quantity exceeds anything we can form an idea of. In an inquiry into their history three questions naturally arise: Did the animals come there and die? or, Were their bodies brought there, and lay exposed? or, Were the bones collected from different places? The first of these conjectures appears to me the most natural; but yet I am by no means convinced of its being the true one. Bones of this description are found in very different situations, which makes their present state more difficultly accounted for. Those in Germany are found in caves; the coast of Dalmatia is said to be almost wholly formed of them ; and we know that this is the case with a large portion ofthe rock of Gibraltar. If none were found in caves, but in solid masses covered with marl or limestone, it would then give the idea of their having been brought together by some strange cause, as a convulsion in the earth, which threw these materials over them ; but this we can hardly form an idea of. Or if they had all been found in caves, we should have imagined these caves were places of retreat for such

in which, however, here and there bones are seen sticking. And here ends this connected series of most remarkable osteolithical caverns, as far as they have been hitherto explored; many more may for what we know exist,hidden, in the same tract of hills. "Mr. Esper has written a history in German of these caves; and given descriptions and plates of a great number of the fossil bones which have been found there. To this work we must refer for a more particular account of them."] * Bones that have been buried with the flesh on acquire a strain wh ich they never los", and those which have been long immersed in water receive a considerable tinge. 40* 462 HUNTER ON THE ANIMAL CECONOMY. animals, and had been so for some thousands of years; and if the bones were those of carnivorous animals and herbivorous, we might have supposed that the carnivorous had brought in many animals of a smaller size which they caught for food. And this, upon the first view, appears to have been the case with those which are the subject of this paper; yet when we consider that the bones are principally of carnivorous animals, we are confined to the supposition of their being only places of retreat. If they had been brought together by any convulsion of the earth, they would have been mixed with the surrounding materials of the mountains, which does not appear to be the case ; for although some are found sticking in the sides ofthe caves incrusted in calcareous matter, this seems to have arisen from their situation to the cave. Such accumulation would have made them coeval with the mountains themselves, which from the recent state ofthe bones I should very much doubt. The difference in the state of the bones shows that there was probably a succession of them for a vast series of years; for if we consider the distance of time between the most perfect having been deposited, which we must suppose were the last, and the present time, we must consider it to be many thousand years. And if we calculate how long these must still remain to be as far decayed as some others are, it will require many thousand years, a sufficient time for a vast accumulation. From this mode of reasoning, therefore, it would appear that they were not brought here at once in a recent state. The animal earth, as it is called, at the bottom of these caves, is supposed to be produced by the rotting of the flesh, which is supposing the animals brought there with the flesh on; but I do conceive that, if the caves had been stuffed with whole animals, the flesh could not have produced one-tenth part of the earth; and, to account for such a quantity as appears to be the produce of animals, I should suppose it the remains ofthe dung of animals who inhabited the caves, and the contents of the bowels of those they lived upon. This is easily conceived from knowing that there is something similar to it, in a smaller degree, in many caves in this kingdom, which are places of retreat for bats in the winter, and even in the summer, as they only go abroad in the evenings. These caves have their bottoms covered with animal earth, for some feet in depth, in all degrees of decomposition, the lowermost the most pure, and the uppermost but little changed, with all the intermediate degrees; in which caves are formed a vast number of stalactites, which might incrust the bones of those that die there.*

* [Hunter probably little suspected that there were caves in this kingdom, like those of Germany, abounding with the remains of extinct mammalia. These caves, especially that of Kirkdale in Yorkshire, and the fossils discovered in them, are admirably described in the * Reliquiae Diluvianae ' of Dr. Buckland ; and it is gratifying to find that the conclusion which Hunter adopted, out of the different hypotheses which he suggests to account for the presence of the bears' bones in the Bayreuth caverns, viz., that these had served as an habitual retreat OBSERVATIONS ON SOME FOSSIL BONES. 463 The bones in the caves in Germany are so much the object of the curious that the specimens are dispersed throughout Europe, which prevent a sufficient number coming into the hands of any one person to make him acquainted with the animals to which they belong. From the history and figures given byEsper it appears that there are the bones of several animals; but what is curious, they all appear to have been carnivorous, which we should not have expected. There are teeth, in number, kind, and mode of setting, exactly similar to the white bear, others more like those of the lion ; but the representations of parts, however well executed, are hardly to be trusted to for the nicer characters, and much less so when the parts are mutilated.* The bones sent by his Highness the Margrave of Anspach agree with those described and delineated by Esper as belonging to the white bear; how far they are of the same species among themselves I cannot say. The heads differ in shape from each other; they are, upon the whole, much longer for their breadth than in any canivorous animal I know of: they also differ from the present white bear, which, as far as I have seen, has a common proportional breadth. It is supposed, indeed, that the heads of the present white bear differ from one another; but the truth of this assertion I have not seen heads enough of that animal to determine. The heads not only vary in shape but also in size; for some of them, when compared with the recent white bear, would seem to have belonged to an animal twice itjS size : while some of the bones correspond in size with those ofthe white bear, and others are even smaller.f There are two ossa humeri, rather of a less size than those of the recent white bear ; a first vertebra, rather smaller; the teelh also vary considerably in size, yet they are all those of the same tribe ; so that the variety among themselves is not less than between them and the recent. In the formation of the head, age makes a considerable difference : the skull of a young dog is much more rounded than an old one; the ridge leading back to the occiput, terminating in the two lateral ones, hardly exists in a young dog; and among the present bones there is the back part of such a head, yet it is larger than the to the living animals, and had thus become the depository of the remains of successive generations, agrees with the theory proposed by Dr. Buckland with reference to the bones of the hyaenas, accumulated at Kirkdale, the chief argument in support of which is derived from the abundance of earthy or bony dung with which the fossils are associated.] * [Remains of an indubitably large feline animal have been found associated with the bears' bones in the Bayreuth and Gaybureuth caverns. The mutilated cranium figured by Leibnitz in his Protogaea, PI. XI., is considered by Soemmering to have belonged to a lion.] f It is to be understood that the bones of the white bear that I have, belonged to one that had been a show, and had not grown to the full or natural size; and I make allowance for this in my assertion that the heads of those incrusted appear to belong to an animal twice the size of our white bear. 464 HUNTER ON THE ANIMAL CECONOMY. head of the largest mastiff; how far the young white bear may vary from the old, similar to the young dog, I do not know, but it is very probable.* Bones of animals under circumstances so similar, although in different parts of the globe, one would have naturally supposed to consist chiefly of those of one class or order in every place, one principle acting in all places.f In Gibraltar they are mostly ofthe ruminating tribe, of the hare kind, and the bones of birds; yet there are some of a small dog or fox, and likewise shells. Those in Dalmatia appear to be mostly of the ruminating tribe ; yet I saw a part ofthe os hyoides of a'horse; but those from Germany are mostly carnivorous. From these facts we should be inclined to suppo'se that their accumulation did not arise from any instinctive mode of living, as the same mode could not suit both carnivorous and herbivorous animals.J In considering animals respecting their situation upon the globe, there are many which are peculiar to particular climates, and others that are less confined, as herrings, mackerel, and salmon ; others again which probably move over the whole extent of the sea, as the shark, porpus, and whale tribe ; while many shell fish must be confined to one spot.§ If the sea had not shifted its situation more than once, and was to leave the land in a very short time, then we could determine what the climate had formerly been by the extraneous fossils of the stationary animals, for those only would be found mixed with those of passage ; but if the sea moves from one place to another slowly, then the remains of animals of different climates may be mixed, by those of one climate moving over those of another, dying, and being fossilized; but this I am afraid cannot * [There are now skulls of the young and old white bear in the Collection of the College of Surgeons in London which confirm Hunter's conjecture respecting the difference of form which is due to age in this genus. It will be seen that Hunter adduces this circumstance merely as one which must be taken intoconsideration in comparing recent and fossil crania of the same genus ; and that he by no means asserts, as Cuvier states he does, that the differences which he had detected between the fossil and recent skulls, and between the different fossil skulls of the cave bears, are of the same nature and degtee.—Ossemens Fossiles, 6me Ed., tom. vii., p. 236. f [This sagacious conjecture has received remarkable confirmation from recent discoveries ; the fossil bones that have been found in Australia appertain for the most part to animals of the marsupial order, and those collected in South America contain a remarkable proportion of Edentata, some of them of gigantic proportions, but all protected by a bony armour analogous to that of the armadillos, which are peculiar to South America.] X [Mr. Lyell thus describes some of the circumstances under which the bonea of animals are accumulated at Gibraltar: " At the north extremity of the rock are perpendicular fissures, on the ledges of which a number of h;iwks nestle and rear their young in the breeding season. They throw down from their nests the bones of small birds, mice, and other animals, on which they feed, and these are gradually united into a breccia of angular fragments of the decomposing limestone with a cement of red earth." (Principles of Geology, vol. iii., p. 158.) § [For a full development of the relation which the geographical distribution of animals bears to the science of Oryctology, or Fossil Remains, the reader is referred to the second and third volumes of Lyell's Principles of Geology.] OBSERVATIONS ON SOME FOSSIL BONES. 465 be made out. By the fossils we may, however, have some idea how the bones of the land animals fossilized may be disposed with respect to those of the sea. If the sea should have occupied any space that never had been dry land prior to the sea's being there, the extraneous fossils can only be those of sea animals; but each part will have its particular kind of those that are stationary mixed with a few of the amphibia, and of sea birds, in those parts that were the skirts of the sea. I shall suppose that when the sea left its place it moved over land where both vegetables and land animals had existed, the bones of which will be fossilized, as also those ofthe sea animals; and if the sea continued long here, which there is reason to believe, then those mixed extraneous fossils will be covered with those of sea animals. Now if the sea should again move, and abandon this situation, then we should find the land and sea fossils above mentioned disposed in this order; and as we begin to discover extraneous fossils in a contrary direction to their formation, we shall first find a stratum of those of animals peculiar to the sea, which were the last formed, and under it one of vegetables and land animals, which were there before they were covered by the sea, and among them those of the sea, and under this the common earth. Those peculiar to the sea will be in depth in proportion to the time ofthe sea's residence and other circumstances, as currents, tides, &c. From a succession of such shiftings of the situations of the sea we may have a stratum of marine extraneous fossils, one of earth, mixed probably with vegetables and bones of land animals, a stratum of terrestrial extraneous fossils, then one of marine productions; but from the sea carrying its inhabitants along with it, wherever there are those of land animals there will also be a mixture of marine ones; and from the sea commonly remaining thousands of years in nearly the same situation, we.have marine fossils unmixed with any others.* All operations respecting the growth or decomposition of animal and vegetable substances go on more readily on the surface of the earth than in it; the air is most probably the great agent in decomposition and combination, and also a certain degree of heat. Thus the deeper we go into the earth we find the fewer changes going on ; and there is probably a certain depth where no change of any kind can possibly take place. The operation of vegetation will not go on at a certain depth, but at this very depth a decomposition can take place, for the seed dies and in time decays; but at a still greater depth the seed retains its life for ages, and

* [The importance of the study of fossil remains in the elucidation of the nature ofthe changes to which the earth's surface has been subject, here dwelt upon by Hunter, was placed in a strong light by the subsequent researches of Cuvier and Brogniart on the structure of the Paris Basin, and the fossils which have rendered it so famous. By the aid of these fossils Cuvier was enabled to refer the succession of strata to several distinct alternations of marine and freshwater formations.] 466 HUNTER ON THE ANIMAL CECONOMY. when brought near enough to the surface for vegetation it grows. Something similar to this takes place with respect to extraneous fossils; for although a piece of wood or bone is dead when so situated as to be fossilized, yet they are sound and free from decomposition, and the depth, joined with the matter in which they are often found, as stone, clay, &c, preserves them from putrefaction, and their dissolution requires thousands of years to complete it; probably they may be under the same circumstances as in a vacuum ; the heat in such situations is uniform, probably in common about 52° or 53°, and in the colder regions they are still longer preserved. I believe it is generally understood that in extraneous fossils the animal part is destroyed, but I find that this is not the case in any I have met with. Shells, and bones of fish,most probably have the least in quantity, having been longest in that state ; otherwise they should have the most; for the harder and more compact the earth, the better is the animal part preserved, which is an argument in proof of their having been the longest in a fossil state. From experiment and observation the animal part is not allowed to putrefy ; it appears only to be dissolved into a kind of mucus, and can be discovered by dissolving the earth in an acid: when a shell is treated in this way the animal substance is not fibrous or laminated, as in the recent shell, but without tenacity, and can be washed off like wet dust; in some, however, it has a slight appearance of flakes. In the shark's tooth, or glosso-petra, the enamel is composed of animal substance and calcareous earth, and is nearly in the same quantity as in the recent; but the central part of the tooth has its animal substance in the state of mucus interspersed in the calcareous matter. In the fossil bones of sea animals, as the vertebrae of the whale, the animal part is in large quantity, and in two states, the one having some tenacity, but the other like wet dust; but in some of the harder bones it is more firm. In the fossil bones of land animals, and those which inhabit the waters, as the sea-horse, otter, crocodile, and turtle, the animal part is in considerable quantity. In the stags' horns dug up in Great Britain and Ireland, when the earth is dissolved, the animal part is in considerable quantity, and very firm. The same observations apply to the fossil bones of the elephant found in England, Siberia, and other parts ofthe globe; also those of the ox kind; but more particularly to their teeth, especially those from the lakes in America, in which the animal part has suffered very little; the inhabitants find little difference in the ivory of such tusks from the recent, but its having a yellow stain ; the cold may probably assist in their preservation. The state of preservation will vary according to the substance in which they have been preserved ; in peat and clay I think the most; however, there appears in general a species of dissolution, for the animal substance, although tolerably firm, in a heat a little above 100° becomes a thickish mucus, like dissolved gum, while a portion from the external surface is reduced to the state of wet dust. OBSERVATIONS ON SOME FOSSIL BONES. 467 In incrusted bones the quantity of animal substance is very different in different bones. In those from Gibraltar there is very little ; it in part retains its tenacity, and is transparent, but the superficial part dissolves into mucus. Those from Dalmatia give similar results when examined in this way. Those from Germany, especially the harder bones and teeth, seem to contain all the animal substance natural to them ; they differ, however, among themselves in this respect. The bones of land animals have their calcareous earth united with the phosphoric acid instead of the aerial,* and I believe retain it when fossilized, nearly in proportion to the quantity of animal matter they contain. The mode by which I judge of this is by the quantity of effervescence ; when fossil bones are put into the muriatic acid it is not nearly so great as when a shell is put into it, but it is more in some, although not in all, than when a recent bone is treated in this way, and this I think diminishes in proportion to the quantity of animal substance they retain ; as a proof of this, those fossil bones which contain a small portion of animal matter produce in an acid the greatest effervescence when the surface is acted on, and very little when the centre is affected by it; however, this may be accounted for by the parts which have lost their phosphoric acid, and acquired the aerial, being easiest of solution in the marine acid, and therefore dissolved first, and the aerial acid let loose. In some bones of the whale the effervescence is very great; in the Dalmatia and Gibraltar bones it is less ; and in those the subject of the present paper it is very little, since they contain by much the largest proportion of animal substance.f * [Carbonic] f [In this Paper we may perceive that Hunter appreciated the value of the study of Fossil Remains, and their application to the elucidation of many important subjects. First, with reference to the extension of our ideas respecting the zoology of this planet, we find him comparing the fossils which are the subject of the text, with their recent analogues, and he shows that they differ both from them and among themselves : his observations and comparisons are, it is true, too general and summary, and it was left to his successors iu this field of inquiry to pursue the comparison with the requisite minuteness anoVprecision, and to give names to the distinct but extinct species. Hunter next briefly alludes to the different situations and climates in the globe, to which animals are more or less confined; and this subject, or the geographical distribution of animals, considered in relation to fossil remains, elucidates, amongst other interesting questions, the changes of temperature to which different parts of the earth have been subject at different epochs. Hunter points out more distinctly, and with more detail, the evidence which extraneous fossils afford respecting the alternations of land and sea, of which the earth's surface has been the theatre; and by his frequent allusion to the " many thousand years" which must have elapsed during these periods, seems to have fully appreciated the necessity of an ample allowance of past time in order to account philosophically for the changes in question. Lastly, he treats of the nature and causes of the different states in which the remains of extinct animals are found ; and many of the fossil bones which were the subject of his chemical experiments are still preserved in his museum (see Nos. 118-130, Physiological Series.) When we turn from the perusal of this highly philosophical memoir to the 46S HUNTER ON THE ANIMAL CECONOMY. 42. DESC RIPTIONS OF SOME ANIMALS FROM NEW SOUTH WALES. BY JOHN HUNTER, F.R.S.

[The following descriptions are interesting, not less from being the first that appeared of some of the most singular of the quadrupeds which characterize the Fauna of Australia, than from the celebrity of their author, of whose contributions to descriptive zoology they are almost the only examples. They form part of the zoological appendix to a "Journal of a voyage to New South Wales, 4to. 1790," published by John White, Esq., Surgeon-General to the settlement, who thus acknowledges the assistance which he derived from the gentlemen by whose cooperation he was " enabled to surmount those difficulties that necessarily attended the description of so great a variety of animals, presented for the first time to the observation of the naturalist, and consequently in the class of nondescripts. Among those gentlemen he has the honour particularly to reckon the names of Dr. Shaw, Dr. Smith, the possessor of the celebrated Linnaean Collection; and John Hunter, Esq., who to a sublime and inventive genius, happily unites a disinterested and generous zeal for the promotion of natural science." Dr. Shaw, who superintended the publication of White's Zoological Appendix, thus introduces the observations contributed by Hunter:— " The nondescript animals of New South Wales occupied a great deal of Mr. White's attention, and he preserved several specimens of them in spirits, which arrived in England in a very perfect state. There was no person to whom these could be given with so much propriety as Mr. Hunter, he, perhaps, being most capable of exnotice of it in the Ossemens Fossils of Cuvier, we must suppose that it could have been but very imperfectly known to the great founder of oryctological science. In the chapter on the 'Ours Fossiles,'Cuvier says: " Le celebre chirurgeon anglais, J. Hunter, dans un Memoire sur les os fossiles, qui ri*a que leur analyse chimique pour objet, et qui est insere dans les Transactions Philosophiques, donne deux belles figures de cranes d'ours fossiles les meillures qui aient paru jusque la, mais sans description detaill£e, et en disant pour toute comparaison que les differentes tetes d'ours de cavernes different autant entre elles qu'elles different de Pourspolaire, et que toutes ces differences ne surpassent point celles que l'age peut produire dans les animaux carnassiers ; assertion vague et meme erronee."—Loc. cit., p. 237. A careful and candid perusal of Hunter's Memoir would doubtless have exonerated the author from this charge in the mind of Cuvier, as it must do in that of every unprejudiced reader. But it would still afford a very inadequate notion of the extent to which Hunter had pursued his study of fossil remains. The interest that he took in them is shown hy the frequent exhortations towards their collection in his letters to Jenner, and his collection at his decease included about 1050 specimens, of which there are 259 belonging to the vertebrate classes (including 70 specimens of fossil fishes, and 40 of reptiles), 116 cephalopods, 116 univalves, 143 bivalves, 35 Crustacea, 163 echinodermata, 109 zoophytes, and 50 fossil vegetable productions.] DESCRIPTIONS OF SOME ANIMALS, ETC. 469 amining accurately their structure, and making out their place in the scale of animals; and it is to him that we are indebted lor the following observations upon them, in which the anatomical structure is purposely avoided, as being little calculated for the generality of readers of a work of this kind."] It is much to be wished that those gentlemen who are desirous of obliging their friends, and promoting the study of natural history, by sending home specimens, would endeavour to procure all the information they can relating to such specimens as they may collect, more especially animals. The subjects themselves may be valuable, and may partly explain their connection with those related to them, so as in some measure to establish their place in nature,* but they cannot do it entirely ; they only give us the form and construction, but leave us in other respects to conjecture, many of them requiring further observation relative to their ceconomy. A neglect in procuring this information has left us almost to this day very ignorant of that part of the natural history of animals which is the most interesting. The Opossum is a remarkable instance of this. There is something in the mode of propagation in this animal, that deviates from all others; and although known in some degree to be extraordinary, yet it has never been attempted, where opportunity offered, to complete the investigation. I have often endeavoured to breed them in England; I have bought a great many, and my friends have assisted me by bringing them or sending them alive, yet never could get them to breed ; and although possessed of a great many facts respecting them, I do not believe my information is sufficient to complete the system of propagation in this class.-f

* [It is interesting to meet with these indications of the spirit in which Hunter prosecuted his zoological researches. To ascertain the affinities of the animals whose structure he explored, or, in other words, to establish a natural system of classification, was not less the aim of Hunter than the determination of the functions ofthe different organs in the animal frame ; and the truth ofthe remark of the necessity of combining observation of the living habits of animals, with anatomical and zoological research, in order to establish entirely their place in nature, as well as to fully understand their ceconomy, is now universally admitted.] t [Since the time of Mr. Hunter, the kangaroo by breeding in this country has afforded the opportunity of elucidating many of the peculiarities of the generative (Economy of the Marsupial quadrupeds. Trrese peculiarities are not confined to the female. In the male, the testicles are situated in an exte rnal fold of the integument, corresponding in situation to the internal fold which constitutes the marsupial pouch in the female, and the scrotum thus formed is consequently anterior to the penis. The cremaster muscles wind round the supplementary bones attached to the pubis, which act as fulcra to the muscles, and enable them to compress the gland with a force which seems to be demanded in consequence ofthe tortuosity of the double vagina along which the semen has to be propelled ,hL\C°ltu? 1S ? °.-g dUrau°n l" tt,e ka"garoo> and ^e scrotum disappear durine the forcible retraction of the testes against the marsupial bones S The female kangaroo is pregnant for the space of thirty-eWht days when uterine birth takes place, and the embryo, now about an inch in length, is 170 HUNTER ON THE ANIMAL CECONOMY. In collecting animals, even the name given by the natives if possible should be known, for a name to a naturalist should mean nothing but that to which it is annexed, having no allusion to anything else, for when it has it divides the idea. This observation applies particularly to the animals which have come from New

transferred, I suspect, by the mouth of the parent, from the vulva to the nipple, where it hangs, protected and concealed by the pouch for about six months. Only two opportunities have as yet occurred for the examination ofthe uterine fcetus. These show that it is nourished chiefly by means of omphalo-mesenteric vessels, which ramify over a large vitelline sac. When the extremities are formed, and the uterine fcetus has attained about two-thirds its size as such, an allantois is developed ; the umbilical arteries coextended with this sac do not, however, as in the placental mammalia, pass to the chorion ; but this membrane continues unorganized, as in the ovoviviparous and oviparous classes, and consequently there is no adhesion of the fcetal membranes to the uterine parietes, and therefore no obstruction to the escape of the embryo (at the premature period destined for its birth) from the uterus into the vagina. The uterus is double in all the marsupiata, and each cavity is of small 6ize, and of a simple elongated form. In the Didelphis dorsigera, each os tincae opens into a long vagina, which makes a sweep outwards, and then converging towards its fellow, opens into the upper end of a cloacal passage, common to the two vagina; and ihe urethra. In the Virginian opossum, each vagina, before describing the outward curvature, sends down a cul-de-sac, which is closely united to the one on the opposite side, but the cavities are distinct. In the kangaroo, the two cul-de-sacs are blended together, so that the vaginra communicate together Doth at their commencement, and also at their termination in the meatus communis. The size of the vaginal cul-de-sacs seems to be in the ratio of the capacity ofthe external pouch. The embryo is adapted to its intra-marsupial existence by a precocious development ofthe respiratory and circulating organs, by a peculiar tubular form of the mouth, and a grooved tongue calculated to retain a firm hold on the elongated nipple ; it has also a peculiar construction of the larynx, somewhat analogous to that of the whale, by which respiration may be safely continued in the foetus while the mother injects the milk down its pharynx. It would seem that the new-born marsupial is incompetent from its feeble and incomplete structure to the office of forcing a stream of milk through the longand tortuous lacteal ducts, since the mammary gland is embraced by a muscle, corresponding to the cremaster in the male, and winding in a similar manner round the marsupial bones ; these therefore aid the expulsion of the milk in the female, as they do that of the semen in the male ; they also in the female add to the power of the mammary muscles in sustaining a portion of the weight of the fcetus which is attached to the nipple. Many have been the conjectures respecting the final intention ofthe premature birth ofthe marsupial animal, and of the various singular modifications of structure necessitated by, and adapted to that circumstance. Since it obtains in quadrupeds of almost every variety of form, and with various modes of locomotion and diversity of diet, it must result from some more general law than individual proportions or habits ofthe parent. It is associated with a marked inferiority of cerebral organization ; but the final purpose will be most probably discovered to relate to some peculiarity in the physical geography of that portion ofthe globe in which the quadrupeds almost exclusively exhibit the marsupial organization. Long-continued droughts and a scarcity of freshwater streams are amongst the most striking features of the climate and territory of Australia; and when we reflect that the principal exceptions to the marsupial organization, viz., the Ornithorhynchus and the Hydromys, or water-rat of ihe colonists, habitually inhabit the freshwater ponds, the peculiarities of the reproduction above described may have reference to the great distances which the mammalia of New South Wales are generally compelled to traverse in order to quench their thirst.] [DESCRIPTIONS OF SOME ANIMALS, ETC. 471 Holland; they are, upon the whole, like no other that we yet know of, but as they have parts in some respects similar to others, names will naturally be given to them expressive of those similarities, which has already taken place; for instance, one is called the kangaroo rat, but which should not be called either kangaroo or rat; I have therefore adopted such names as can only be appropriated to each particular animal, conveying no other idea.* Animals admit of being divided into great classes, but will not so distinctly admit of subdivision without interfering with each other. Thus the class called quadrupeds is so well marked that even the whole is justly placed in the same class, birds the same, amphibia (as they are called) the same, and so of fishes, &c.; but when we are subdividing these great classes into their different tribes, genera and species, then we find a mixture of properties,

* [The evils of implying false affinities and of suppressing differences of primary importance, which would have resulted from referring the newly discovered quadrupeds of Australia to the known Linnaean genera, as was afterwards done by Dr. Shaw, were sagaciously avoided by Hunter. And had the same expanded views been taken by his colleague, zoology would not at the present time have been burdened with such useless synonyms as Didelphys petaurus, Didelphys penicillata, Didelphys viverrina, Didelphys obesula, &c, and the zoologists of the continent might have been spared the task of rectifying the errors of that arrangement, which arising from an ignorance of the anatomical distinctions of the animals in question, and from a disregard ofthe modifications presented by their teeth and locomotive extremities, consisted in grouping with the American opossums the species above quoted,—species which now form respectively the types of the genera Petaurus, Phascogale, Dasyurus and Perameles. Hunter, on the contrary, adopted the more natural and philosophical method of accurately pointing out the differences and resemblances of each species, retaining for them, like Adanson with reference to the nondescripts of Senegal, the native names, instead of applying to them Linnaean generic appellatives, which could only serve to propagate erroneous ideas of the objects to which they were attached. These reflections are so obviously suggested by the text, that the following is offered as an apology for their insertion: the writer of a volume entitled a " Discourse on the Study of Natural History," which by some unfortunate casually has appeared in the same series of publications as that which contains Herschel s admirable Discourse on Natural Philosophy, introduces the name of John Hunter in his account of the naturalists who have contributed to the rise and progress of zoology for the sole purpose of instituting a disparaging comparison between that great and original thinker and the author of the General Zoology. Dr. Shaw, Mr. Swainson observes, " was unquestionably the writer of nearly all the zoological descriptions in White's Voyage to New South Wales, whereas he (John Hunter) merely wrote the account of five of the quadrupeds and these are neither named nor scientifically characterized." Now the fact is that Hunter's descriptions of the parts best adapted for zoological characters are so exact and so minute that a zoologist has no difficult m assigning the spec.es to the most recent zoological subdivisions, as any one may convince himself who compares the account of the Tapuo Tafa with°he characters assigned by Temm.nck to his genus Phascogale. But Hunter added also observations on the differences and peculiarities of the internal suture 0f the marsupial quadrupeds yet Dr. Shaw was so blind to the true meZd, of advancing the science of zoology, and so little able to appreciate thJlabour* of his colleague to this end, that science was deprived of the benefit of Hnnt? anatomical description of five marsupial genera, because thlv wTo ; n « "er,S estimation, little calculated for the readefsor^To^Yp™X,] W ' 472 HUNTER ON THE ANIMAL CECONOMY. some species of one tribe partaking of similar properties with a species of another tribe.

Of the Kangaroo* This animal (probably from its size) was the principal one taken notice of in this island; the only parts at first brought home were some skins and skulls, and I was favoured with one of the skulls from Sir Joseph Banks. As the teeth of such animals as are already known in some degree point out their digestive organs, I was in hopes that I might have been able to form an opinion of the particular tribe ofthe animals already known to which the kangaroo should belong; but the teeth did not accord with those of any one class of animals I was acquainted with, therefore I was obliged to wait with patience till I could get the whole; and in many of its other organs the deviation from other animals is not less than in its teeth. In its mode of propagation it very probably comes nearer to the opossum than any other animal, although it is not at all similar to it in other respects. Its hair is of a grayish-brown colour, similar to that ofthe wild rabbit of Great Britain, is thick and long when the animal is old ; but it is late in growing, and when only begun to grow it is like a strong down; however, in some parts it begins earlier than others, as about the mouth, &c. In all the young kangaroos yet brought home (although some as large as a full-grown rat) they have all the marks of a fcetus : no hair; ears lapped close over the head; no marks on the feet of having been used in progressive motion: the large nail on the great toe sharp at the point, and the sides of the mouth united something like the eyelids of a puppy just whelped, having only a passage at the anterior part. This union ofthe two lips on the sides is of a particular structure ; it wears off as it grows up, and by the time it is the size of a small rabbit, disappears.

Of the Teeth of the Kangaroo. The teeth of this animal are so singular that it is impossible from them to say what tribe it is of. There is a faint mixture in them, corresponding to those of different tribes of animals. Take the mouth at large, respecting the situation of the teeth, it would class in some degree with the Scalpris dentata,\ in a fainter degree with the horse and ruminants; and with regard to the line of direction of all the teeth, they are very like those of the Scalpris dentata. The fore teeth in the upper jaw agree with the hog, and those in the lower, in number, with the Scalpris dentata, but with regard to

* [The species here for the first time described is the Macropus major of modern systems : several other species of the same genus have since been discovered.] f [This tribe includes the rat, &c. (it corresponds to the order Glires of Linnaeus and the Rodentia of Cuvier.)] DESCRIPTIONS OF SOME ANIMALS, ETC. 473 position, and probably use, with the hog. The grinders would seem to be a mixture of hog and ruminant, the enamel on their external and grinding surfaces rather formed into several cutting edges than points. There are six incisors in the upper jaw and only two in the lower, but these two are so placed as to oppose those of the upper ; five grinders in each side of each jaw, the most anterior of which is small.* The proportions of some of the parts of this animal bear no analogy to what is common in most others. The disproportions in the length between the fore legs and the hind are very considerable, also in their strength, yet perhaps not more than in the jerboa. This disproportion between the fore legs and the hind is principally in the more adult; for in the very young, about the size of a half-grown rat, they are pretty well proportioned ; which shows that at the early period of life they do not use progressive motion.t The proportions of the different parts of which the hind legs are composed are very different. The thigh of the kangaroo is extremely short, and the leg is very long. The hind foot is uncommonly long, on which, to appearance, are placed three toes, the middle toe by much the largest and the strongest, and looks something like the long toe of an ostrich. The outer toe is next in size ; and what appears to be the inner toe, is two inclosed in one skin or covering. The great toe nail much resembles that of an ostrich, as also the nail ofthe outer toe; and the inner, which appears to be but one toe, has two small nails, which are bent and sharp.J

* [Hunter appears to have taken this description from a skull in which the first deciduous molar was still retained. The total number of molares which are developed in the jaws of a kangaroo are seven on each side of each jaw; the greatest number in use at any given time is four on each side of each jaw; a posterior or fifth molar may be visible above the socket in the dry skull, but it does not cut the gum for use till the anterior one is pushed out. The succession of the molares is from behind forwards in both jaws. The first deciduous molar, upper jaw, resembles the first permanent false molar in thepotoroo; it is elongated, compressed, and traversed by a longitudinal sharp middle ridge, at the internal base of which are three small tubercles. It is for cutting rather than bruising. The corresponding tooth, lower jaw, is similar in form, but smaller, and has one tubercle in the posterior part of the inner side of the base. In some species of kangaroo, as the Macropus elegans, the false molar is permanent, but its earlier loss in Macr. major does not warrant a generic distinction. The second deciduous molar has the form of the ordinary grinders, but is smaller; it is shed before the first. The third is similar, but somewhat larger; and so also of the fourth: this grinder is much worn in old skulls, and in the lower jaw is lost, leaving then only —i molares in aged individuals. The fifth, sixth, and seventh follow each other from behind forwards, and are of equal size. Before the fourth grinder is in place the permanent incisores are gained ; these closely resemble their predecessors, but are somewhat larger. In °the Macropus major the exterior incisor upper jaw presents two inflected folds of enamel • these are wanting in the corresponding teeth ofthe smaller species, which retain the spurious molares.] t [At a still earlier period the fore legs, following the usual law of develoD ment, exceed the hind legs in length.] v~ X [Each of these toes has it prosper metatarsal and phalangeal bones 1 41* 'J 474 HUNTER ON THE ANIMAL CECONOMY. From the heel along the under side of the foot and toe, the skin is adapted for walking upon. The fore legs, in the full-grown kangaroo, are small in proportion to the hind, or the size of the animal; the feet, or hands, are also small. The skin on the palm is different from that on the back of the hand and fingers. There are five toes or fingers on this foot, the middle rather the largest; the others become very gradually shorter, and are all nearly of the same shape. The nails are sharp, fit for holding. The tail is long in the old, but not so long, in proportion to the size of the animal, in the young. It would seem to keep pace with the growth of the hind legs, which are the instruments of progressive motion in this animal, and which would also show that the tail is a kind of second instrument in this action.* The under lip is divided in the middle, each side rounded off at the division. It has two clavicles, but they are short, so that the shoulders are not thrown out.

The Potoroo or Kangaroo Rat]

The head is flat sideways, but not so much so as in the true Scalpris dentata. The ears are neither long nor short, but much like those of a mouse in proportion to the size of the animal. The fore legs are short in comparison to the hind. There are four toes on the fore-feet,J the two middle are long, and nearly of equal lengths, with long narrow tails, slightly bent; the two side toes are short, and nearly equal in size, but the outer rather the

* [It must be remembered that at this time Hunter had never seen the living kangaroo, but the numerous opportunities of witnessing the locomotion of this remarkable animal afforded to subsequent observers have all testified to the sagacity of his provision ofthe use ofthe tail.] f [This animal differs from the kangaroo in having two small canines, in addition to the six incisors in the upper jaw. The first compressed or false molar on each side of each jaw, which is shed in the great kangaroo, is here retained. The first incisors of the upper jaw are also relatively longer and more curved. The potoroo, therefore, forms ihe type of a distinct genus, which was named by Illiger ' Hypsiprymnus,'from the Greek word 'r^^i^voc, signifying the hinder parts raised. Of this genus three or four species have been indicated. The skin and cranium of the individual described by Hunter, and figured in the Appendix to White's Voyage, are preserved in the Museum of the College of Surgeons. The skull agrees in size and form, as also the proportions of the stuffed skin, with the skeleton of the Hypsiprymnus murinu?, given in Pander and D'Alton'a ' Skelete der Beutellhiere,'' tab. iii. We give the following admeasurements from the original specimen: ft. in. In. From the end of the nose to the vent . . . 13 0 Length of the tail.......0 8 7£ Length of the skull . . . . . . 0 3 3 Length of the foot......0 3 3 The Hypsiprymnus murinus of Illiger is the Hypsiprymnus White of Quoy and Gaimard, the Macropus minor of Shaw.] X [In the specimen here described, as in the rest of the genus, there are five toes on the fore foot, but the fifth is so small as scarcely to perform any part of the office of a toe. DESCRIPTIONS OF SOME ANIMALS, ETC. 475 largest. From the nails on the two middle toes one would suppose that the animal burrowed. Their hind legs are long, and it is in their power to stand either on the whole foot, or on the toes only. On the hind legs are three toes, the middle one large, and the two side ones short ;* the tail is long. The hair on the body is rather thin ; it is of two kinds, a fur, and a long hair, which last becomes exterior from its length. The fur is the finest, and is composed of serpentine hairs; the long hair is stronger, and is also serpentine, for more than two-thirds of its length near to the skin, and terminates in a pretty strong pointed end, like the quill of a hedgehog ; it is of a brownish-gray colour, something like the brown or gray rabbit, with a tinge of a greenish-yellow. * It has a pouch on the lower part of the belly ; the mouth opens forwards, and the cavity extends backwards to the pubis, where it terminates; on the abdominal surface of this pouch are four nipples or two pair, each pair placed very near the other.f

This animal is of the size of a small rabbit; it has a broad flat body; the head a good deal resembles that of the squirrel; the eyes are full, prominent, and large ; the ears broad and thin ; its legs short, and its tail very long. Between the fore and hind legs, on each side, is placed a doubling of the skin of the side, which, when the legs are exiended laterally, is as it were pulled out, forming a broad lateral wing or fin, and when the lcgsare made use of in walking, this skin, by its elasticity, is drawn close to the side of the animal, and forms a kind of ridge, on which the hair has a peculiar appearance. In this respect it is very similar to the flying squirrel of America. It has five toes, on each fore foot, with sharp nails. The hindfoot has also five toes, but differs considerably from the fore-foot; one of the toes may be called a thumb, having a broad nail, something like that of the monkey or opossum. What answers to the fore and middle toes are united in one common covering, and appear like one toe with two nails; this is somewhat similar to the kangaroo. The two other toes are in the common form; these

* [There are four toes on this foot, as in the great kangaroo, but the two inner ones are so conjoined by a common sheath of integument as to act as but one.] t [The genera Macropus and Hypsiprymnus are principally distinguished from the other marsupialia anatomically by having a large stomach, complicated with saccnli, produced as in the colon, by being puckered upon longitudinal bands.] t [This animal is the type of the genus Pteaurus, which is characterized by the following dental formula : incisors —, molares spuriae |-H, molares tubercu ,.44 4~4 = 3'1# *l is tne 'argest known species, and is the Petaurus Taguanoides of Desmarest, and the Didelphys Petaurus of Shaw. The original specimen, described and figured in White's Appendix is preserved in the Museum of the Royal College of Surgeons.] 476 HUNTER ON THE ANIMAL CECONOMY. four nails are sharp, like those on the fore foot. This formation of the foot is well calculated for holding anything while it is moving its body or its fore foot to other parts ; a property belonging (probably) to all animals which move from the hind parts, such us the monkey, mocock, mongoose, opossum, parrot, leech, &c. Its hair is very thick and long, making a very fine fur, especially on the back. It is of a dark brown-gray on the upper part, a light white gray on the lower side of what may be termed the wing, and white on the under surface, from the neck to the parts adjacent to the anus.

This animal is about the size of a racoon, is of a dark gray colour on the back, becoming rather lighter on the sides, which terminates in a rich brown on the belly. The hair is of two kinds, a long hair and a kind of fur, and even the long hair at the roots is of the fur kind. The head is short, the eyes rather prominent; the ears broad, not peaked. The teeth resemble those of all the animals from that country I have hitherto seen. The incisors are not continued into the grinders by intermediate teeth, although there are two teeth in the intermediate space in the upper jaw, and one in the lower. The incisors are similar to those of the kangaroo, and six in number in the upper jaw, opposed by two in the lower, which have an oblique surface extending some distance from their edge, so as to increase the surface of contact. There are two cuspidati on each side in the upper jaw, and only one in the lower; five grinders on each side of each jaw, the first rather pointed, the others appear nearly of the same size, and quadrangular in their shape, with a hollow running across their base from the outside to the inner, which is of some depth; and another which crosses it, but not so deep, dividing the grinding surface into four points. On the fore foot there are five toes, the inner the shortest, resembling, in a slight degree, a thumb. The hind foot resembles a hand, or that of the monkey and opossum, the great toe having no nail, and opposing the whole sole of the foot, which is bare. The nails on the other toes, both ofthe fore and hind foot, resemble in a small degree those of the cat, being broad and covered ; and the last bone ofthe toe has a projection on the under side, at the articulation. Each nail has, in some degree, a small sheath, covering its base when drawn up.t The tail is long, covered with

* [This species is now called the vulpine opossum, or vulpine phalanerer (Phalang,sta Vulpina,) and is the type of a genus of which the species are not confined to Australia, but some were known, as inhabitants of the Indian isles, to the older naturalists. The dental characters are described in the text.] f [In the hinder foot the two toes next the thumb are inclosed in a common sheath of integument as far as the ungual phalanx : this is the commencement of that peculiar degradation of the second and middle toe which is carried to so great an extreme in the kangaroos and potoroos. The term Phalangista was given to the crenus in question in consequence of this binding together of the phalanges of two of the toes in the hind feet.] DESCRIPTIONS OF SOME ANIMALS, ETC. 477 long hair, except the under surface of that half towards the termination, ofthe breadth of half an inch, becoming broader near tne tip or termination: this surface is covered with a strong cuticle, and is adapted for laying hold.

This animal is the size of a rat, and has very much the appearance of the martin cat, but hardly so long in the body in proportion to its size. The head is flat forwards, and broad from side to side, especially between the eyes and ears; the nose is peaked, and projecting beyond the teeth, which makes the upper jaw appear to be considerably longer than the lower; the eyes are pretty large; the ears are broad especially at their base, not becoming regularly narrower to a point,| nor with a very smooth edge, and having a small process on the concave or inner surface, near to the base. It has long whiskers from the sides of the cheeks, which begin forwards, near the nose, by small and short hairs, and become longer and stronger as they approach the eyes.J It has very much the hair of a rat, to which it is similar in colour ; but near to the setting on of the tail it is of a lighter brown, forming a broad ring round it. The fore feet are shorter than the hind, but much in the same proportion as those of the rat; the hind feet are more flexible. There are five toes on the fore feet, the middle the largest, falling off on each side nearly equally; but the fore or inner toe is rather shortest; they are thin from side to side; the nails are pretty broad, laterally, and thin at their base; not very long, but sharp: the animal walks on its whole palm, on which there is no hair. The hind feet are pretty long, and have five toes; that which answers to our great toe is very short, and has no nail; the next is the longest in the whole, falling gradually off to the outer toe; the shape of the hind toes is the same as in the fore feet, as are likewise the nails; it walks nearly on the whole foot. The tail is long, and covered with long hair, but not all of the same colour. The teeth of this creature are different from any other animal yet known. The mouth is full of teeth; the lower jaw narrow, in comparison to the upper, more especially backwards, which allows of much broader grinders in this jaw than in the lower, and which occasions the grinders in the upper jaw to prpject considerably over those in the lower. In the middle the cuspidati oppose one another; the upper piercers or holders go behind those ofthe lower; the second class of incisors in the lower jaw overtop those of the upper, while the two first in the lower go within, or behind those of the upper. In the upper

* [This animal is the Phascogale penicillata of Temminck, (Monographies de Mammalogie, p. 58.), Dasyurus Tafa of Geoffroy, Didelphis penicillata of Shaw.] f [Temminck describes the ears of Phascogale penicillata as being "arrondies par le haut."—Loc. cit., p. 59.] t ["Les moustaches des levres sont place's plus pres des yeux que de nez."__ Ibid.~\ 478 HUNTER ON THE ANIMAL CECONOMY. jaw, before, the holders ' (canines)', there are four teeth « (incisors)' on each side, three of which are pointed, the point standing on the inner surface; and the two in front are longer, standing more obliquely forwards, and appear to be appropriated for a particular use.* The holders ' (canines)' arc a little way behind the last fore teeth, to allow those ofthe lower jaw to come between ; they are pretty long. The cuspidati (spurious molares) on each side become longer and larger towards the grinders (true molares) ; they are points or cones placed on a broad base. There are four grinders on each side, the middle two the largest, the last the least; their base is a triangle, of the scalenus kind, or having one angle obtuse and two acute. Their base is composed of two surfaces, an inner and an outer, divided by processes or points; it is the inner that the grinders of the lower jaw oppose, when the mouth is regularly shut. The lower jaw has three fore teeth, or incisors, on each side, the first considerably the largest, projecting obliquely forwards: the other two of the same kind, but smaller; the last the smallest. The holder (canine) in this jaw is not so large as in the upper jaw, and close to the incisors. There are three cuspidati '(false molares),f the middle one the largest, the last the least: these are cones standing on their base, but not on the middle, rather on the anterior side. There are four grinders, the two middle the largest, and rather quadrangular, each of which has a high point or cone on the outer edge, with a smaller, and three more diminutive on the inner edge. It is impossible to say critically what the various forms of these teeth are adapted for, from the general principles of teeth. In the

* [This superiority of size of the two middle incisors of the two jaws is one ofthe characters which distinguish Phascogale from Dasyurus."] f [This is the second and most decisive distinguishing generic character between Phascogale and Dasyurus, the latter having only two false molars on each side of each jaw, instead of three. Had Fischer, Lesson, and other zoologists compared the description of the teeth in the text with that given by Temminck in his Monographies de Mammalogie,as characterizing his genus Phascogale, they could not have hesitated to refer the Tapoa tafa of Hunter to that genus, and the catalogues of mammalia need not have contained the imaginary species Dasyurus Tafa, which M. Temminck observes " n'a point ete vue depuis par aucun naturaliste," and which species Lesson suspects to be founded on the immature Btate ofthe spotted Dasyure (Dasyurus viverrinus). But neither observation nor analogy favour the idea of spots being acquired by age; on the contrary, the examples of the lion and the puma, which are spotted only when young, show that they are more likely to be lost. In the Hunterian collection the posterior half of the body of the individual described by Hunter is preserved, to show the marsupium and teats; these are eight in number, and arranged in a circle. The tail perfectly corresponds with the specimens of Phascogale penicillata, and with M. Temminck's description, being "couverte de poils assez courts a la base, tres-long, raides, et en pinceau vers la pointe " (loc. cit., p. 59) ; and the long hairs are black.] DESCRIPTIONS OF SOME ANIMALS, ETC. 479

front we have what may divide and tear off; behind those there are holders or destroyers; behind the latter, such as will assist in mashing, as the grinders of the lion, and other carnivorous animals; and last of all, grinders, to divide parts into smaller portions, as in the graminivorous tribe ; the articulation of the jaw, in some degree, admits of all those motions.

A Dingo, or Dog of New South Wales.

This animal is a variety of the dog, and, like the shepherd's dog in most countries, approaches near to the original of the species, which is the wolf; but is not so large, and does not stand so high on its legs. The ears are short and erect, the tail rather bushy; the hair, which is of a reddish-dun colour, is long and thick, but straight. It is capable of barking, although not so readily as the European dog, is very ill-natured and vicious, and snarls, howls and moans like dogs in common. Whether this is the only dog in New South Wales, and whether they have it in a wild state, is not mentioned, but I should be inclined to believe they had no other, in which case it will constitute the wolf of that country; and that which is domesticated is only the wild dog tamed, without having yet produced a variety, as in some parts of America. THE END. /3 >■■ ■ s •;' :j LIBRARY OF MEDICINE O-i. NLM020922468