Among the subjects of Hunter’s physiological investigation in 1785 was the mode of growth of deer’s antlers. As he possessed the privilege of making experiments on the deer in Richmond Park, he in July of that year had a buck there caught and thrown, and tied one of its external carotid arteries. He observed that the antler which obtained its blood supply therefrom, then half-grown, became in consequence cold to the touch. Hunter debated with himself whether it would be shed in due time, or be longer retained than ordinarily. To his surprise he found, on re-examining the antler a week or two later, when the wound around the ligatured artery was healed, that it had regained its warmth, and was still increasing in size. Had, then, his operation been in some way defective? To determine this question, the buck was killed and sent to Leicester Fields. On examination Hunter ascertained that the external carotid had been duly tied, but that certain small branches of the artery above and below the ligature had enlarged, and by their anastomoses had restored the blood supply of the growing part. Thus it was evident that under “the stimulus of necessity,” to use a phrase of the experimenter, the smaller arterial channels are capable of rapid increase in dimensions to perform the offices of the larger.[23] It happened that, in the ensuing December, there lay in one of the wards of St George’s Hospital a patient admitted for popliteal aneurism. The disease must soon prove fatal unless by some means arrested. Should the surgeon, following the usual and commonly fatal method of treatment, cut down upon the tumour, and, after tying the artery above and below it, evacuate its contents? Or should he adopt the procedure, deemed by Pott generally advisable, of amputating the limb above it? It was Hunter’s aim in his practice, even if he could not dispense with the necessity, at least to diminish the severity of operations, which he considered were an acknowledgment of the imperfection of the art of healing, and compared to “the acts of the armed savage, who attempts to get that by force which a civilized man would get by stratagem.” Since, he argued, the experiment with the buck had shown that collateral vessels are capable of continuing the circulation when passage through a main trunk is arrested, why should he not, in the aneurism case, leaving the absorbents to deal with the contents of the tumour, tie the artery in the sound parts, where it is tied in amputation, and preserve the limb? Acting upon this idea, he ligatured his patient’s femoral artery in the lower part of its course in the thigh, in the fibrous sheath enclosing the space since known as “Hunter’s canal.”[24] The leg was found, some hours after the operation, to have acquired a temperature even above the normal.[25] At the end of January 1786, that is, in six weeks’ time, the patient was well enough to be able to leave the hospital. Thus it was that Hunter inaugurated an operation which has been the means of preserving to hundreds life with integrity of limb—an operation which, as the Italian P. Assalini, who saw it first performed, testifies, “excited the greatest wonder, and awakened the attention of all the surgeons in Europe.”
Early in 1786 Hunter published his Treatise on the Venereal Disease, which, like some of his previous writings, was printed in his own house. Without the aid of the booksellers, 1000 copies of it were sold within a twelvemonth. Although certain views therein expressed with regard to the relationship of syphilis have been proved erroneous, the work is a valuable compendium of observations of cases and modes of treatment (cf. John Hilton, Hunt. Orat. p. 40). Towards the end of the year appeared his Observations on certain parts of the Animal Oeconomy, which, besides the more important of his contributions to the Philosophical Transactions, contains nine papers on various subjects. In 1786 Hunter became deputy surgeon-general to the army; his appointment as surgeon-general and as inspector-general of hospitals followed in 1790. In 1787 he received the Royal Society’s Copley medal, and was also elected a member of the American Philosophical Society. On account of the increase in his practice and his impaired health, he now obtained the services of Home as his assistant at St George’s Hospital. The death of Pott in December 1788 secured to him the undisputed title of the first surgeon in England. He resigned to Home, in 1792, the delivery of his surgical lectures, in order to devote himself more fully to the completion of his Treatise on the Blood, Inflammation and Gunshot Wounds, which was published by his executors in 1794. In this, his masterpiece, the application of physiology to practice is especially noticeable. Certain experiments described in the first part, which demonstrate that arterialization of the blood in respiration takes place by a process of diffusion of “pure air” or “vital air” (i.e. oxygen) through membrane, were made so early as the summer of 1755.
Hunter in 1792 announced to his colleagues at St George’s, who, he considered, neglected the proper instruction of the students under their charge, his intention no longer to divide with them the fees which he received for his hospital pupils. Against this innovation, however, the governors of the hospital decided in March 1793. Subsequently, by a committee of their appointing, a code of rules respecting pupils was promulgated, one clause of which, probably directed against an occasional practice of Hunter’s, stipulated that no person should be admitted as a student of the hospital without certificates that he had been educated for the medical profession. In the autumn two young Scotchmen, ignorant of the new rule, came up to town and applied to Hunter for admission as his pupils at St George’s. Hunter explained to them how he was situated, but promised to advance their request at the next board meeting at the hospital on the 16th of October. On that day, having finished a difficult piece of dissection, he went down to breakfast in excellent spirits and in his usual health. After making a professional call, he attended the board meeting. There the interruption of his remarks in behalf of his applicants by a flat contradiction from a colleague brought on one of the old spasmodic heart attacks; he ceased speaking, and retired into an adjoining room only to fall lifeless into the arms of Dr Robertson, one of the hospital physicians. After an hour had been spent in vain attempts to restore animation, his body was conveyed to his house in a sedan chair.[26] His remains were interred privately on the 22nd of October 1793, in the vaults of St Martin’s in the Fields. Thence, on the 28th of March 1859, through the instrumentality of F. T. Buckland, they were removed to Abbot Islip’s chapel in Westminster Abbey, to be finally deposited in the grave in the north aisle of the nave, close to the resting-place of Ben Jonson.
Hunter was of about medium height, strongly built and high-shouldered and short-necked. He had an open countenance, and large features, eyes light-blue or grey, eyebrows prominent, and hair reddish-yellow in youth, later white, and worn curled behind; and he dressed plainly and neatly. He rose at or before six, dissected till nine (his breakfast hour), received patients from half-past nine till twelve, at least during the latter part of his life, and saw his outdoor and hospital patients till about four, when he dined, taking, according to Home, as at other meals in the twenty years preceding his death, no wine. After dinner he slept an hour; he then superintended experiments, read or prepared his lectures, and made, usually by means of an amanuensis, records of the day’s dissections. “I never could understand,” says W. Clift, “how Mr Hunter obtained rest: when I left him at midnight, it was with a lamp fresh trimmed for further study, and with the usual appointment to meet him again at six in the morning.” H. Leigh Thomas records[27] that, on his first arrival in London, having by desire called on Hunter at five o’clock in the morning, he found him already busily engaged in the dissection of insects. Rigidly economical of time, Hunter was always at work, and he had always in view some fresh enterprise. To his museum he gave a very large share of his attention, being fearful lest the ordering of it should be incomplete at his death, and knowing of none who could continue his work for him. “When I am dead,” said he one day to Dr Maxwell Garthshore, “you will not soon meet with another John Hunter.” At the time of his death he had anatomized over 500 different species of animals, some of them repeatedly, and had made numerous dissections of plants. The manuscript works by him, appropriated and destroyed by Home, among which were his eighty-six surgical lectures, all in full, are stated to have been “literally a cartload”; and many pages of his records were written by Clift under his directions “at least half a dozen times over, with corrections and transpositions almost without end.”
To the kindness of his disposition, his fondness for animals, his aversion to operations, his thoughtful and self-sacrificing attention to his patients, and especially his zeal to help forward struggling practitioners and others in any want abundantly testify. Pecuniary means he valued no further than they enabled him to promote his researches; and to the poor, to non-beneficed clergymen, professional authors and artists his services were rendered without remuneration. His yearly income in 1763-1774 was never £1000; it exceeded that sum in 1778, for several years before his death was £5000, and at the time of that event had reached above £6000. All his earnings not required for domestic expenses were, during the last ten years of his life, devoted to the improvement of his museum; and his property, this excepted, was found on his decease to be barely sufficient to pay his debts. By his contemporaries generally Hunter was respected as a master of the art and science of anatomy, and as a cautious and trustworthy if not an elegant or very dexterous operator. Few, however, perceived the drift of his biological researches. Although it was admitted, even by Jesse Foot,[28] that the idea after which his unique museum had been formed—namely, that of morphology as the only true basis of a systematic zoological classification—was entirely his own, yet his investigations into the structure of the lower orders of animals were regarded as works of unprofitable curiosity. One surgeon, of no inconsiderable repute, is said to have ventured the remark that Hunter’s preparations were “just as valuable as so many pig’s pettitoes”;[29] and the president of the Royal Society, Sir Joseph Banks, writing in 1796, plainly expressed his disbelief as to the collection being “an object of importance to the general study of natural history, or indeed to any branch of science except to that of medicine.” It was “without the solace of sympathy or encouragement of approbation, without collateral assistance,”[30] and careless of achieving fame—for he held that “no man ever was a great man who wanted to be one”—that Hunter laboured to perfect his designs, and established the science of comparative anatomy, and principles which, however neglected in his lifetime, became the ground-work of all medical study and teaching.
In accordance with the directions given by Hunter in his will, his collection was offered for purchase to the British government. But the prime minister, Pitt, on being asked to consider the matter, exclaimed: “What! buy preparations! Why, I have not money enough to purchase gunpowder.” He, however, consented to the bestowal of a portion of the king’s bounty for a couple of years on Mrs Hunter and her two surviving children. In 1796 Lord Auckland undertook to urge upon the government the advisability of acquiring the collection, and on the 13th of June 1799, parliament voted £15,000 for this purpose. Its custodianship, after refusal by the College of Physicians, was unanimously accepted by the Corporation of Surgeons on the terms proposed. These were in brief—that the collection be open four hours in the forenoon, two days every week, for the inspection and consultation of the fellows of the College of Physicians, the members of the Company of Surgeons and persons properly introduced by them, a catalogue of the preparations and an official to explain it being at those times always at hand; that a course of not less than twenty-four lectures[31] on comparative anatomy and other subjects illustrated by the collection be given every year by some member of the Company; and that the preparations be kept in good preservation at the expense of the Corporation, and be subject to the superintendence of a board of sixteen trustees.[32] The fulfilment of these conditions was rendered possible by the receipt of fees for examinations and diplomas, under the charter by which, in 1800, the Corporation was constituted the Royal College of Surgeons. In 1806 the collection was placed in temporary quarters in Lincoln’s Inn Fields, and the sum of £15,000 was voted by parliament for the erection of a proper and commodious building for its preservation and extension. This was followed by a grant of £12,500 in 1807. The collection was removed in 1812 to the new museum, and opened to visitors in 1813. The greater part of the present edifice was built in 1835, at an expense to the college of about £40,000; and the combined Hunterian and collegiate collections, having been rearranged in what are now termed the western and middle museums, were in 1836 made accessible to the public. The erection of the eastern museum in 1852, on premises in Portugal Street, bought in 1847 for £16,000, cost £25,000, of which parliament granted £15,000; it was opened in 1855.
The scope of Hunter’s labours may be defined as the explication of the various phases of life exhibited in organized structures, both animal and vegetable, from the simplest to the most highly differentiated. By him, therefore, comparative anatomy was employed, not in subservience to the classification of living forms, as by Cuvier, but as a means of gaining insight into the principle animating and producing these forms, by virtue of which he perceived that, however different in form and faculty, they were all allied to himself. In what does life consist? is a question which in his writings he frequently considers, and which seems to have been ever present in his mind. Life, he taught, was a principle independent of structure,[33] most tenaciously held by the least highly organized beings, but capable of readier destruction as a whole, as, e.g., by deprivation of heat or by pain, in young than in old animals. In life he beheld an agency working under the control of law, and exercising its functions in various modes and degrees. He perceived it, as Abernethy observes, to be “a great chemist,” a power capable of manufacturing a variety of substances into one kind of generally distributed nutriment, and of furnishing from this a still greater variety of dissimilar substances. Like Harvey, who terms it the anima vegetiva, he regarded it as a principle of self-preservation, which keeps the body from dissolution. Life is shown, said he, in renovation and action; but, although facilitated in its working by mechanical causes, it can exist without action, as in an egg new-laid or undergoing incubation. It is not simply a regulator of temperature; it is a principle which resists cold, conferring on the structures which it endows the capacity of passing some degrees below the freezing-point of ordinary inanimate matter without suffering congelation. Hunter found, in short, that there exists in animals a latent heat of life, set free in the process of death (see Treatise on the Blood, p. 80). Thus he observed that sap if removed from trees froze at 32° F., but within them might be fluid even at 15°; that a living snail placed in a freezing mixture acquired first a temperature of 28°, and afterwards of 32° ere it froze; and that, whereas a dead egg congealed immediately at 32°, a living egg did so only when its temperature had risen to that point after a previous fall to 29¼°. The idea that the fluid and semifluid as well as the solid constituents of the body contain the vital principle diffused through them he formed in 1755-1756, when, in making drawings illustrative of the changes that take place in the incubated egg, he noted specially that neither the white nor the yolk undergoes putrefaction. The blood he, with Harvey, considered to possess a vitality of its own, more or less independent of that of the animal in which it circulates. Life, he held, is preserved by the compound of the living body and the source of its solid constituents, the living blood. It is to the susceptibility of the latter to be converted into living organized tissue that the union of severed structures by the first intention is due. He even inclined to the belief that the chyle has life, and he considered that food becomes “animalized” in digestion. Coagulation of the blood he compared to the contraction of muscles, and believed to be an operation of life distinct from chemical coagulation, adducing in support of his opinion the fact that, in animals killed by lightning, by violent blows on the stomach, or by the exhaustion of hunting, it does not take place. “Breathing,” said Hunter, “seems to render life to the blood, and the blood continues it in every part of the body.”[34] Life, he held, could be regarded as a fire, or something similar, and might for distinction’s sake be called “animal fire.” Of this the process of respiration might afford a constant supply, the fixed life supplied to the body in the food being set free and rendered active in the lungs, whilst the air carried off that principle which encloses and retains the animal fire.[35] The living principle, said Hunter, is coeval with the existence of animal or vegetable matter itself, and may long exist without sensation. The principle upon which depends the power of sensation regulates all our external actions, as the principle of life does our internal, and the two act mutually on each other in consequence of changes produced in the brain. Something (the “materia vitae diffusa”) similar to the components of the brain (the “materia vitae coacervata”) may be supposed to be diffused through the body and even contained in the blood; between these a communication is kept up by the nerves (the “chordae internunciae”).[36] Neither a material nor a chemical theory of life, however, formed a part of Hunter’s creed. “Mere composition of matter,” he remarked, “does not give life; for the dead body has all the composition it ever had; life is a property we do not understand; we can only see the necessary leading steps towards it.”[37] As from life only, said he in one of his lectures, we can gain an idea of death, so from death only we gain an idea of life. Life, being an agency leading to, but not consisting of, any modification of matter, “either is something superadded to matter, or else consists in a peculiar arrangement of certain fine particles of matter, which being thus disposed acquire the properties of life.” As a bar of iron may gain magnetic virtue by being placed for a time in a special position, so perhaps the particles of matter arranged and long continued in a certain posture eventually gain the power of life. “I enquired of Mr Hunter,” writes one of his pupils,[38] “if this did not make for the Exploded Doctrine of Equivocal Generation: he told me perhaps it did, and that as to Equivocal Generation all we cd have was negative Proofs of its not taking Place. He did not deny that Equivocal Generation happened; there were neither positive proofs for nor against its taking place.”
To exemplify the differences between organic and inorganic growth, Hunter made and employed in his lectures a collection of crystallized specimens of minerals, or, as he termed them, “natural or native fossils.” Of fossils, designated by him “extraneous fossils,” because extraneous respecting the rocks in which they occur, he recognized the true nature, and he arranged them according to a system agreeing with that adopted for recent organisms. The study of fossils enabled him to apply his knowledge of the relations of the phenomena of life to conditions, as exhibited in times present, to the elucidation of the history of the earth in geological epochs. He observed the non-occurrence of fossils in granite, but with his customary scientific caution and insight could perceive no reason for supposing it to be the original matter of the globe, prior to vegetable or animal, or that its formation was different from that of other rocks. In water he recognized the chief agent in producing terrestrial changes (cf. Treatise on the Blood, p. 15, note); but the popular notion that the Noachian deluge might account for the marine organisms discovered on land he pointed out was untenable. From the diversity of the situations in which many fossils and allied living structures are found, he was led to infer that at various periods not only repeated oscillations of the level of the land, lasting thousands of centuries, but also great climatic variations, perhaps due to a change in the ecliptic, had taken place in geological times. Hunter considered that very few fossils of those that resemble recent forms are identical with them. He conceived that the latter might be varieties, but that if they are really different species, then “we must suppose that a new creation must have taken place.” It would appear, therefore, that the origin of species in variation had not struck him as possible. That he believed varieties to have resulted from the influence of changes in the conditions of life in times past is shown by a somewhat obscure passage in his “Introduction to Natural History” (Essays and Observations, i. 4), in which he remarks, “But, I think, we have reason to suppose that there was a period of time in which every species of natural production was the same, there being then no variety in any species,” and adds that “civilization has made varieties in many species, which are the domesticated.” Modern discoveries and doctrines as to the succession of life in time are again foreshadowed by him in the observation in his introduction to the description of drawings relative in incubation (quoted in Pref. to Cat. of Phys. Ser. i. p. iv., 1833) that: “If we were capable of following the progress of increase of the number of the parts of the most perfect animal, as they first formed in succession, from the very first, to its state of full perfection, we should probably be able to compare it with some one of the incomplete animals themselves, of every order of animals in the creation, being at no stage different from some of those inferior orders; or, in other words, if we were to take a series of animals from the more imperfect to the perfect, we should probably find an imperfect animal corresponding with some stage of the most perfect.”
In pathological phenomena Hunter discerned the results of the perturbation of those laws of life by which the healthy organism subsists. With him pathology was a science of vital dynamics. He afforded principles bearing not on single complaints only, but on the effects of injury and disease in general. To attempt to set forth what in Hunter’s teaching was new to pathology and systematic surgery, or was rendered so by his mode of treatment, would be well-nigh to present an epitome of all that he wrote on those subjects. “When we make a discovery in pathology,” says Adams, writing in 1818, “we only learn what we have overlooked in his writings or forgotten in his lectures.” Surgery, which only in 1745 had formally ceased to be associated with “the art and mystery of barbers,” he raised to the rank of a scientific profession. His doctrines were, necessarily, not those of his age: while lesser minds around him were still dim with the mists of the ignorance and dogmatism of times past, his lofty intellect was illumined by the dawn of a distant day.
Authorities.—See, besides the above quoted publications, An Appeal to the present Parliament ... on the subject of the late J. Hunter’s Museum (1795); Sir C. Bell, A Lecture ... being a Commentary on Mr J. Hunter s preparations of the Diseases of the Urethra (1830); The President of the Royal College of Surgeons of England, Address to the Committee for the Erection of a Statue of Hunter (Lond., March 29, 1859); Sir R. Owen, “Sketch of Hunter’s Scientific Character and Works,” in Tom Taylor’s Leicester Square (1874), also in Hunter’s Works, ed. by Palmer, vol. iv. (1837), and in Essays and Observations; the invaluable catalogues of the Hunterian Collection issued by the Royal College of Surgeons; and numerous Hunterian Orations. In the Journal of a Voyage to New South Wales, by John White, is a paper containing directions for preserving animals, printed separately in 1809, besides six zoological descriptions by Hunter; and in the Natural History of Aleppo, by A. Russell, are remarks of Hunter’s on the anatomy of the jerboa and the camel’s stomach. Notes of his lectures on surgery, edited by J. W. K. Parkinson, appeared in 1833 under the title of Hunterian Reminiscences. Hunter’s Observations and Reflections on Geology, intended to serve as an introduction to the catalogue of his collection of extraneous fossils, was published in 1859, and his Memoranda on Vegetation in 1860.