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a small extent for the purposes of scientific research. Hunter's view of the coagulation of the blood as a vital act has never been substantiated, but is rather discountenanced by more recent inquiries. His belief that the coagulated blood on the surfaces of wounds might become, like the lymph, the seat of the formation and inosculation of vessels, doubtless tended to confirm him in the notion of the vital character of the coagulating process; and this supposed fact would, if true, sufficiently prove the accuracy of his opinion; but his belief in this respect seems to have been the result of imperfect observavation, nor does there appear any reason to suppose that such formation of vessels in coagula ever really takes place.
One very important conclusion was certainly arrived at by Hunter with regard to the blood-namely, that its vital properties reside principally and primarily in the colourless portion. This he established by the observation, that in the embryo of mammiferous animals the red particles are entirely absent, and that the blood is consequently in the same apparent condition as in the invertebrata when fully developed. So late as the year 1832, this fact was brought forward by MM. Delpech and Coste as a new discovery, doubtless in ignorance of Hunter's priority.
On the whole, Hunter's researches into the vital properties of the blood are perhaps more valuable as suggesting important points of inquiry, than as establishing valid conclusions respecting them; to which, as already remarked, it was simply impossible that he should have attained, in the absence of adequate implements and means of investigation. But in this their suggestive tendency, they cannot be too highly estimated; and, whether considered in relation to their immense extent, the penetrating sagacity with which they were conducted, or the important pathological inferences immediately deduced from them, they must be admitted to have formed one of the most remarkable series of investigations in which any single inquirer was ever engaged. Hunter, then, is unquestionably entitled to the merit of having been the first to promulgate a rational and consistent doctrine of the life of the blood, and to lay a broad and sure foundation for future inquiry into its vital properties and uses.
Among the vital phenomena connected with the blood, and the vessels which contain it, those of inflammation naturally presented themselves to a mind like Hunter's, as a highly interesting subject of inquiry. On this subject all had been till his time mere conjecture, and scarcely a single really philosophical observation had been made upon it. Hunter, as is well known, referred inflammation mainly to an increased action of the vessels of the part; but this, not as many have supposed, in the sense of an increased contraction, but in the sense of an action the result of which is an increase of their capacity.
"We must suppose it an action in the parts to produce an increase of size to answer particular purposes; and this I should call an action of dilatation, as we see the uterus increase in size in the time of uterine gestation, as well as the os tincæ in the time of labour, the consequence of the preceding actions, and necessary to the completion of those which are to follow."
• Treatise on the Blood, &c., p. 324.
It was probably his notion of common, or, as he first called it, healthy inflammation, as being essentially a restorative and not a morbid process, that led him to this view of the action of the vessels. But whether Hunter were right or wrong as to the nature of the action going on in the vessels, and whether we regard their dilatation as an active state induced by an effort of the vital force, or a passive one resulting from diminished contractility, the fact of their dilatation admits of no dispute. Nor is there so much practical difference as might at first be imagined between the views of Hunter and those of Vacca, Allen, and their followers; for Hunter distinctly states his belief that both the muscular contractility and the elasticity of the vessels are diminished.
"The power of muscular contraction would seem to give way in inflammation, for they certainly dilate more in inflammation than the extent of the elastic power would allow; and it must also be supposed that the elastic power of the artery must be dilated in the same proportion.”*
This is very badly expressed, but Hunter evidently means to say that the muscular power is diminished, and that the elastic coat of the vessels is dilated beyond what its usual elasticity would admit of. All the hypotheses seem, therefore, virtually to agree as to a diminution of contractile power in the vessels; only those based on Vacca's seem to regard this in the light of a sort of paralysis and diminution of vital power, while that of Hunter refers it to "an action of dilatation,” which appears to us merely a strange mode of expression for an organic increase of size, or actual growth of the vessels,
On the question, whether there be an increase in the number of the vessels of the inflamed part, or whether the appearance of increased vascularity depends merely on the dilatation of the ordinary vessels, and the unusual quantity of blood they contain, Hunter professes himself uncertain. But in considering the state of the vessels, he did not lose sight of the state of the blood itself; and he arrived at the conclusion that there is a tendency to separation in its constituent parts, and a disposition among its red particles to cohere and separate themselves from the general mass.
"In all inflammatory dispositions in the solids, whether universal or local, the blood has an increased disposition to separate into its component parts, the red globules becoming less uniformly diffused, and their attraction to one another becomes stronger, so that the blood, when out of the vessels, soon becomes cloudy or muddy, and dusky in its colour, and when spread over any surface it appears mottled, the red blood attracting itself and forming spots of red. This is so evident in many cases that it is hardly necessary to wait till the whole coagulates to form a judgment of it. When the blood has not an inflammatory disposition, the stream has a degree of uniformity and transparency in its appearance; but it is only an eye accustomed to it that can make this distinction."+
The accustomed eye of Hunter here led him to conclusions which the microscopic eye of more recent observers has confirmed. The only
* On the Blood, &c., p. 324.
† Lectures on the l'rinciples of Surgery, p. 235.
point connected with the phenomena of inflammation in which Hunter was in error as to the facts of the case, was his belief that the blood moved quicker than usual in the inflamed vessels; whereas it is now well known that it moves much slower, and sometimes ceases to move altogether. The fact, however, that the velocity of the blood is really increased in the vessels immediately adjacent to those which are the seat of inflammation, renders this error of the less importance.
Setting aside this one error, then, it would appear that Hunter's actual conclusions respecting the proximate cause of inflammation were, that the vessels of the part are dilated, and contain more blood than usual; that the blood has a tendency to resolve itself into its constituent parts, and that the red corpuscles acquire an increased attraction for each other. On the whole, we believe this will be found to be pretty nearly the amount of our positive knowledge on the subject up to the present time.
A very important feature in Hunter's view of inflammation, consists in his division of it into the adhesive, the suppurative, and the ulcerative, a division founded on the most scrutinizing observation of its phenomena, whether in the progress of disease, the limitation of morbid processes, or the reparation of injuries.
It seems not a little singular, and it is moreover much to be regretted, that Hunter did not include mortification as one of the terminations of inflammation, and that a subject so congenial to the general tenor of his inquiries as the state of the vessels in gangrene, and the processes instituted by nature for the separation of sphacelated parts, should have received so small a share of his attention.
But Hunter's discoveries were not confined to placing adhesion, suppuration, and ulceration in their true practical relations to inflammation. He investigated each of these processes minutely, and entered fully into their pathological details. His observations on suppuration were regarded at the time, and for a long time after, as proving that pus was a secretion from the inflamed vessels; but the recent progress of inquiry is unfavourable to this conclusion, and we have been led back, by one of those singular retrogressions which sometimes occur in the history of science, to a view of the subject which approaches more nearly to that of Boerhaave and some of his followers, than to that of But the observations of Hunter on the organization of lymph in the adhesive process stand fast, allowance being of course made for an unacquaintance, which was then universal, with the intervention of cells in the earlier stages of the formation of parts. And he was the first to establish the true nature of the ulcerative process, which, from the times of Galen to his own, had been regarded as an erosion of the solids by the fluids of the part; but which he proved to be effected by the action of the absorbent vessels. He was the first, also, to show the manner in which nature operates in the formation of granulations, and the filling up and cicatrization of abscesses, and other solutions of continuity which are not directly repaired by the adhesive process.
The mind of Hunter was too comprehensive to allow him to rest contented with views, however luminous, of so important a process as
that of inflammation, till they were extended to the modifications which it undergoes, as influenced by the peculiar vital endowments of the different tissues in which it is developed. The study of general anatomy had not yet taken the definite form, or the particular designation, which it was destined shortly after to assume in the hands of Bichat; but the principle prevails throughout the writings of Hunter, and it is impossible to compare these with the writings of the French anatomist, without arriving at the conclusion that Bichat either borrowed very largely from Hunter without acknowledgment, or that he had no acquaintance with his works; the latter would be the more charitable conclusion, though we fear the former is by far the more probable one.
Hunter, however, fully recognising, if he nowhere formally announces, the "doctrine of the tissues," carefully describes the phenomena and effects of inflammation as exhibited in the mucous, serous, and synovial membranes, in the cellular and cutaneous textures, in the osseous and fibrous structures, and, in fact, in every tissue throughout the body.
He recognised, also, every variety of inflammation with which we are now acquainted-acute and chronic, healthy and unhealthy, phlegmonous and erysipelatous, common and specific. He described it as modified by the gouty and scrofulous diatheses. He was familiar with the fact, that erysipelatous inflammation invades other textures beside the cutaneous, and he well knew the tendency of this kind of inflammation to become indefinitely diffused, in the absence of that adhesive disposition by which healthy inflammation sets limits to its own progress. The particular phenomena attending inflammation of the veins were altogether unknown, till Hunter gave a full and accurate account of them; notwithstanding which, the subject seems to have been nearly as much neglected as before, till the publication of Mr. Hodgson's treatise 'On Diseases of the Arteries and Veins,' in 1815, which drew more general attention to it.
Not only did Hunter thus variously illustrate the processes of inflammation in their local effects, and in their modifications in different tissues. His observations on the constitutional disturbances arising from them were of at least equal value. That various febrile and nervous disorders attended local inflammation, wounds, and injuries, must have been a familiar fact from the earliest times; but Hunter was the first to describe these distinctly and faithfully, to associate particular forms of local and constitutional disease, to expound the sympathies of different organs and systems on which they depend, and to bring physiological reasoning to bear directly and profitably on the phenomena of disease. All these topics have now become so much a matter of course, that it is not easy to imagine a period of our art, comparatively recent, in which they were either altogether neglected, or made the subject of crude hypotheses, founded merely on conjecture, or hasty and imperfect observation. Yet such assuredly was the state of things when the genius of Hunter arose, and shed a new and permanent light on the progress of surgery. The late Mr.
Abernethy, who lived when these great changes had only just been brought about, and who, having been himself an ingenious and successful labourer in this newly-opened field of inquiry, must be esteemed a highly competent witness, thus expresses himself on the subject:
"An evil seems to me to have arisen from the artificial division of the healing art into the medical and surgical departments. This division has caused the attention of the physician and surgeon to be too exclusively directed to those diseases which custom has arbitrarily allotted to their care. The effects of local disorders upon the constitution have, in consequence, been too little attended to; and, indeed, I know of no book to which I can refer a surgical student for a satisfactory account of those febrile and nervous affections which local disease produces, except that of Mr. Hunter.”*
Indeed, the very term "constitutional" appears to have come into everyday use, in consequence of the general recognition of truths which Hunter was the first to explain.
"In his pathology," says Mr. Green, "Hunter, by contemplating life as an agency working under the control of law, remained true to the principle already secured in his physiology; and it enabled him to regard the living body in disease, no less than in health, as a living whole and an organic unity. Thus we find him not only recognising the living body as a constitution by virtue of which it forms a system of interdependent parts, and of balanced forces mutually reacting and combining to one end; but also raising into notice the fact that these powers may and do exist in various degrees of intensity, and relative subordination, the result being, in each instance, the constitution of the individual, with its marked peculiarities. And if, from this vantage ground, he was led to determine the pathological significance of the terms susceptibility,' disposition,' irritability,' and the like, and to penetrate the nature of hereditary tendencies;' it also induced him to devote a large portion of his lectures to a consideration of sympathy, the term being intended to express the community, and as it were consent, of feeling and action, which preserve the bond of interdependence in all the parts and actions of the living body in their conspiration to an organic whole. He saw it was from a knowledge of morbid sympathy that we are enabled to anticipate the immediate and remote effects of injury to the living frame; and that it is under the conditions of sympathy that we have to study the nature and end of constitutional irritation in its various forms. And as many of the actions excited by sympathy are for the purpose of effecting processes which tend to the repair of injuries, and to the removal of disease, the principle which he establishes supplies an intelligible meaning to the so-called vis medicatrix nature, as the law of integrity, or the ever-present tendency to integration, which, in all life, having produced a whole, ever tends to preserve and restore that which it has produced."+
We have quoted this passage because, though somewhat peculiar in its phraseology, it appears to us to be very full of thought, and to take in much of the general scope of Hunter's views of the animal
Considering, then, that we owe to Hunter the true knowledge of inflammation throughout the wide range of its phenomena, and the original and masterly illustration of the constitutional effects of local
* On the Constitutional Origin and Treatment of Local Diseases, p. 1. + Address delivered before the Royal College of Surgeons, March 29th, 1859, as reported in the Lancet.