Page:Encyclopædia Britannica, Ninth Edition, v. 12.djvu/405

391 HUNTER 391 the Blood, p. 80). Thus he observed that sap if removed from trees froze at 32 Falir., but within them might be fluid even at 15 ; that a living snail placed in a freezing mixture acquired first a tempera ture of 28, and afterwards of 32 J 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 29|. The idea that the fluid and semifluid as well as the solid constitu ents of the body contain the vital principle diffused through them he formed in 1755-6, 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 &quot; animalized &quot; indigestion. Coagula tion 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. &quot;Breathing,&quot; said Hunter, &quot; seems to render life to the blood, and the blood continues it in every part of the body.&quot; 1 Life, he held, could be regarded as a fire, or something similar, and might for distinction s sake be called &quot;animal fire.&quot; 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. 2 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 &quot; materia vitae ditfusa &quot;) similar to the components of the brain (the &quot; materia vitas coacervata&quot;) 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 &quot; chordte internuncice&quot;). 3 Neither a material nor a chemical theory of life, however, formed a part of Hunter s creed. &quot;Mere composition of matter,&quot; he remarked, &quot;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. &quot; 4 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, &quot;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.&quot; 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. &quot; I enquired of Mr Hunter,&quot; writes one of his pupils, 3 &quot;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 c d 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. &quot; To exemplify the differences between organic and inorganic growth, Hunter made and employed in his lectures a collection of crystal lized specimens of minerals, or, as he termed them, &quot;natural or native fossils.&quot; Of fossils, designated by him &quot;extraneous fossils,&quot; 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 lie 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, 2 Essays and Observations,. 113. lb., p. 90. 1 Treatise on t &amp;gt;e Moorl, p. K3. 3 Treatise on the Dloocl, p. 89. P. P. Staple, with the loan of whose volume of MS. notes of Hunter s &quot;Chirur- KMW Lectures,&quot; dated, on the lust page, Sept. JO, 1787, the writer has been JRvicired by Dr W. H. Broadbent. lasting thousands of centuries, but also great climatic variations, perhaps due to a change in the ecliptic, had taken place in geolo gical 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 dif ferent species, then &quot;we must suppose that a new creation must have taken place.&quot; 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 &quot; Introduction to Natural History &quot; (Essays and Ob servations, i. 4), in which he remarks, &quot; 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,&quot; and adds that &quot;civilization has made varieties in many species, which are the domesticated.&quot; Modern discoveries and doc trines 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 to incubation (quoted in Pref. to Cat. of Phys Scr., i. p. iv., 1833) that: &quot; 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 scries of animals from the more imperfect to the perfect, we should probably find an imperfect animal corre sponding with some stage of the most perfect.&quot; 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 presc nt an epitome of all that he wrote on those subjects. &quot; When we make a discovery in pathology,&quot; says Adams, writing in 1818, &quot;we only learn what we have overlooked in his writings or forgotten in his lectures. &quot; Surgery, which only in 1745 had formally ceased to be associated with &quot; the art and mystery of barbers,&quot; 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. See, besides the above quoted publications, An Appeal to the present Parlia ment. ... on the subject of the late J. Hunters Museum, 1795; Sir C. Bell, A Lecture .... being a Commentary on Mr J Hunter s preparations of the Di.&amp;lt;- eases 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 Hur.hr, Lond., March 29, 1859 ; Professor Owen, &quot; Sketch of Hunter s Scientific Character and Works,&quot; in Tom Taylor s Leicester Square, 1874, also in Hunter s Works, ed. by Palmer, vol. iv., 1837, and in Essays and Obterrations ; tlv invaluable catalogues of the Hunrerian Collection issued by the Royal College of Surgeons ; and numerous Hunterian Ora ions. In the Journal of a Voyage to Xew 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 t]c.atnral History of Aleppo, by A. Russell, are remarks of Hunter s on the anatomy of thn jorbiia 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 intro duction to the catalogue of his collection of extraneous fossils, was published in 1859, and his Memoranda on Vegetation in 18GO. it&quot;. H. 15.) HUNTER, WILLIAM (1718-1783), a celebrated physio logist and physician, and the first great teacher of anatomy in England, was born May 23, 1718, at East Kilbride, Lanark. He was the seventh child of his parents, and an elder brother of John Hunter, the distinguished surgeon. When fourteen years of age he was sent to the university of Glasgow, where he studied for five years. He had originally been intended for the church, but, scruples con cerning subscription arising in his mind, he followed the advice of his friend William Cullen (see CULLEN, vol. vi. p. 694), and resolved to devote himself to physic. During 1737-40 he resided with Cullen at Hamilton, and then, with a view to increasing his medical knowledge before settling in partnership with his friend, he spent the winter of 1740- 41 at Edinburgh, and thence went to London. There Dr James Douglas, an anatomist and obstetrician of some note, to whom he had been recommended, engaged his services as a tutor to his son, and as a dissector, and assisted him to enter as a surgeon s pupil at St George s Hospital, and to procure the instruction of the anatomist Dr Nicholls. Dr Douglas died in April 1742, but Hunter still continued to live with his family. In 1746 Hunter undertook in place of Mr Samuel Sharpe the delivery, for a society of