"It results obviously, from these experiments, that the influence which the pus exercises on the blood is far from being the same, according as the pus is fresh, or has existed so long out of the living body as to have become putrid. Fresh pus has no appreciable action on the blood; putrid pus acts on it in the same way as ammonia does; it destroys at once the globules and the fibrin. But, what is remarkable, this destruction does not happen immediately; and it is necessary that some hours should elapse of contact between them before the blood begins to present traces of alteration.” (p. 120.)

Hence the author concludes, that when pus circulates in the blood the effects on this liquid will depend on the qualities of the pus; and that it is not, in the event of pus altering the blood, its globules but the ammoniacal product which is formed at the expense of the pus itself, which acts injuriously on the blood. He also concludes that it is this ammoniacal product which is transferred on the scalpel from putrefying bodies, and causes those changes which are noticed in the blood, and those symptoms which follow, when punctures have been received with the poisoned instrument; symptoms of the same sort as those which are produced by admission of pus, in certain states, into the circulation. In short, it is to this product that he ascribes the typhoid symptoms which supervene under these circumstances; and the absence of the usual effect of inflammation, when this happens to be present at the same time, or of the fibrin, is ascribed to the operation of the same agent.

HEMORRHAGE. The fifth article, on the state of the blood in hemorrhages, is a long one, but, as much of it is occupied by references to authors, and reasonings in favour of a certain view which the author entertains of the nature of the blood in this morbid condition, what we have to notice, as comparatively new and interesting on this head, admits of being very briefly stated.

"The diminution of the fibrin in relation to the globules is the grand condition of the blood which favours the production of hemorrhages; the relation of these two facts is so constant, that it appears to me impossible not to regard the one as the cause of the other. And that it need not be maintained that it is the hemorrhage which produces in the blood the diminution of the fibrin, it suffices to observe, that it is necessary that the loss of blood should be very abundant in order to produce this effect, and that I have seen the fibrin diminished in these cases, when the quantity of blood lost could certainly not account for it. I add, as an argument which seems to me unanswerable, that if it were the hemorrhage which produced a change in the composition of the blood, we should certainly find the globules diminished in a proportion yet greater than the fibrin ; but this not only does not occur, but the globules are the most commonly then in excess compared to the fibrin." (p. 127.)

He mentions two states, of a different kind, in which the law still holds good of a diminution of the fibrin in relation to the globules, which may favour the production of hemorrhages. In the one the only change occurs in the globules, which have become elevated above their normal amount, and hence the hemorrhages of plethora. In the other the fibrin alone is essentially altered, and has become less abundant than usual. This is the condition of the blood in scorbutus. He mentions an instance in which he had an opportunity of examining the blood of scorbutus. The trunk, the face, and the limbs were covered with petechiae, and large ecchymoses; the gums were soft, swelled, and bleeding, and epistaxis. occurred from time to time; the pulse was 60, the head was affected with a sense of weight and vertigo. The blood which was drawn contained

119 of globules, 86 in solids of the serum, and only 1.6 in fibrin. It was not in cases of the general hemorrhagic tendency only that he ascertained the diminution of the fibrin, but also in cases of cerebral hemorrhage.

"Whether the blood escape from several solids simultaneously, or from one only, facts lead to the conclusion that in the second case, as well as in the first, there are hemorrhages which may depend on this,—that the blood, deprived of its normal quantity of fibrin, has lost, by that circumstance, a part of its plasticity; and thus we come to recognize, in an alteration of the blood, the point de depart of certain morbid phenomena, the cause of which is the most commonly ascribed to a lesion of the solids. The cases in which the fibrin is only diminished in reference to the globules which are in excess, belong, from their symptoms, to the cases of hemorrhage termed active, and the cases in which the quantity of the fibrin is actually diminished belong to those of hemorrhages termed passive. The attentive study of the alterations of the blood comes, then, to afford a new support to this ancient division, which contains theories we could not admit, but which could not be overlooked by the principles of treatment, or by clinical observation." (p. 134.)

In his memoir, in the 'Annales de Chimie,' M. Andral conjectures that in purpura hemorrhagica the fibrin will be found on examination to be very scanty, and the close analogy between that disease and the one he describes as scorbutus, renders it probable that the blood in both will hereafter be found to be of much the same characters. The hemorrhages in both have been long conceived to depend on a change in the fibrin, and the opinion would claim assent, were it not that certain observations made by most respectable authors, have furnished facts which are utterly irreconcileable with it. Thus Deyeux and Parmentier found in three cases of scorbutus the blood about as rich in fibrin, and the clot as consistent, as in health; the late Dr. Parry, of Bath, found the blood in two cases of purpura, to form a firmly contracted coagulum, covered with a buffy coat; and Dr. Babington, too, in a case which presented many of the symptoms of that disease, or of sea scurvy, found the blood of a like firm character, and also surmounted by a buffy coat. Doubtless, M. Andral would endeavour to get rid of all these cases, as he actually does of the first three, by contending that the amount of fibrin was owing to some intercurrent inflammation. But, allowing the fact to be so, it is not the less a serious objection to his doctrine of the dependence of the hemorrhages on a deficiency of the fibrin; for from whatever source the fibrin was derived in these cases, it was present in, at least, its normal proportion; and in the cases of Parry and Babington, probably in excess; yet, notwithstanding, the hemorrhages occurred. The subject therefore manifestly stands in need of additional investigation.

DROPSY. The facts relating to the blood in dropsies, may be divided into those which are negative and those which are positive. M. Andral passes in review the influence of diminution of the fibrin and then of the globules, in producing dropsical effusions, and finds that neither has any direct concern with their manifestation. If a deficiency of the globules were adequate to the production of dropsy, that symptom would doubtless be common in chlorosis, which it certainly is not: and if a decrease of the fibrin were capable of leading to dropsical effusion, we should expect to find this occurrence in scorbutus and purpura and typhoid fever. Yet there is one condition of the blood, he conceives, which we have a right

to regard as entailing necessarily the occurrence of dropsy; namely, a diminution of the albumen of the blood. Those who are acquainted with the researches of Drs. Bostock, Christison, and Babington, do not need to be informed that in Bright's disease of the kidney, when the albumen is present in any considerable quantity in the urine, it is proportionally defective in the serum of the blood, and it is in that disease alone, and dependent on the cause in question, that M. Andral has satisfied himself of the intimate connexion between the deficiency of the albumen and the occurrence of dropsy. The occurrence of the dropsy in the acute stage of the disease, when none of the ingredients of the blood are deficient but the albumen, appears to favour this view of the source of the serous infiltrations, in preference to that of Sabatier and Solon, who ascribe it in general terms to the tenuity of the blood considered as a whole,-a condition of it, however, which is confined to the more advanced periods of the disease. Dr. Christison suggests, that in the acute stage it is the deficiency of the albumen which constitutes the condition on which the dropsy depends; while he seems to concur with the authors mentioned in ascribing the infiltrations of the advanced periods to the general deficiency of solid matter in the blood. But if the deficiency of any of the ingredients of the blood is to be regarded as the cause of the dropsy, it must be that of the albumen; for in other respects the blood in this disease of the kidney, in so far as the amount of its natural organic elements is concerned, has precisely the same constitution as the blood of chlorosis, with the single exception that it is also deficient in albumen, which, according to Andral, does not occur in chlorosis. These facts seem to justify the opinion that it is essentially on the deficiency of the albumen that the dropsy depends in Bright's disease. And yet, with all this appearance of proof in favour of the influence of a diminution of the albumen, we should be sorry that further inquiry should be foreclosed by a general acquiescence in this doctrine-and for various reasons. In the first place, because it is well known that in not a few cases dropsy never supervenes, although the amount of albumen in the urine demonstrates that there must be a great deficiency of it in the blood. Secondly, because the deficiency of albumen in the blood is but one of the alterations which this liquid undergoes in disease of the kidney; and, indeed, it is when the albumen is most deficient, i. e. in the acute stage, that other suspicious alterations are the most likely to exist in their greatest degree, namely, the accumulation of those matters, urea and salts, which are not evacuated with the urine in nearly their natural quantity. And, thirdly, because the degree and extent of the dropsy has not been found to have any direct relation to the degree of the coagulability of the urine, that secretion being sometimes found but slightly coagulable when the dropsy is very great, and, as already stated, sometimes absent altogether when the urine abounds in albumen. We do not think that sufficient attention has yet been bestowed on the amount of the salts of the serum, in dropsy from diseased kidney; and this is the more to be regretted, because it is quite a supposable circumstance that their accumulation in the blood may have some influence on the secretion of the various tissues by their stimulant properties. We have sometimes, also, ventured to ask ourselves the question, whether the great proclivity to inflammatory ac

tion which obtains in this disease may not be owing in some measure to this state of the blood.

It is not certain that other conditions of the blood, besides those which occur in cases of diseased kidney, may not be sometimes the sources of dropsy; such, more especially, as result from long-continued privation. of nutritious aliment. M. Andral conjectures that in such cases also the albumen of the serum becomes ultimately lessened, and that the deficiency constitutes the pathological condition on which the dropsy depends, an opinion which he thinks is supported by what occurs in sheep which have been long kept in moist localities and insufficiently nourished. Under these circumstances the albumen of the animals' blood was found to have become lessened, at the same time that the animals became hydropic. We have no details, however, from which to judge of the force of this argument, or of the exact nature of the pathological circumstances in which these animals were found.

ORGANIC AND NERVOUS DISEASES. The two short chapters on the blood of organic and nervous diseases, contain little that is worthy of notice. The general tendency of chronic diseases is to lessen the amount of the globules, thereby producing the anemic aspect characteristic of most of those which materially affect the health. The fibrin is always liable to increase on the supervention of inflammatory action, but is in other circumstances not apt to have its ordinary proportions materially disturbed

ART. VIII.

Views upon the Statics of the Human Chest, Animal Heat, and Determination of Blood to the Head. By JULIUS JEFFREYS, F.R.S. &c.— London, 1843. 8vo, pp. 234.

MR. JEFFREYS is very generally known to the profession as the ingenious inventor of the "Respirator." He is the author of various scientific memoirs of merit, and, among others, of an interesting series of papers on "artificial climates," which appeared in the Medical Gazette, (1842, Nos. xxii to liii.) The work before us contains an exposition of those views of the physiology of respiration, which, among other practical results, led to the construction of the instrument referred to. It contains also the views of animal heat, and of determinations of blood, which the author has been led to adopt; illustrated by a number of interesting observations and reflections made during a long residence in tropical climates. These refer chiefly to the effects produced by the peculiar habits of different nations in respect to their food and clothing; to the phenomena developed during remarkable states of the atmosphere as regards its temperature, moisture, and density.

Part I is devoted to the statics of the chest. The author divides the air of respiration into four quantities: 1st, the residual air, or that which cannot be expelled from the lungs, but remains after a full and forcible expiration; 2d, the supplementary air, or that which can be expelled by a forcible expiration, after an ordinary out-breathing; 3d, the breath, or tidal air; and 4th, the complementary air, or that which can be inhaled after an ordinary inspiration. The volume of these four quantities, Mr. Jeffreys estimates as follows;

This estimate gives 250 cubic inches as the average volume which the chest contains after an ordinary expiration, consisting of residual and supplementary air, and constituting, together, what Mr. Jeffreys denominates the resident air. The estimate of the first quantity is that of Dr. Bostock. The estimates of the supplementary air and of the breath differ somewhat from those which have been stated by other observers. The supplementary air was estimated by Jurin at 220, and by Dr. Bostock at 160 or 170 cubic inches; by John Bell, on the other hand, it was computed to be as low as 70. From the very careful experiments of Dr. Menzies, the volume of the breath was estimated by him to average 40 cubic inches; an estimate which Mr. Jeffreys justly ascribes to the fact that the observations were made under circumstances which induced laborious breathing, and which was therefore too high. The observations of Mr. Jeffreys on this point appear to have been made with much care and judgment, and probably approximate as nearly as can be expected to the truth.

The author takes considerable credit to himself for pointing out that the air of respiration, or the breath, can have no direct concern in the oxydation of the blood, that it can only renew in part the resident air, and by gradual admixture with it, during successive respirations, ultimately reach the air-cells. He asserts that physiologists have always spoken of the air of respiration as acting directly upon the blood in the air-cells, and of it," when breathed out, as having given up a portion of its oxygen to the blood, and having received from the blood, carbonic acid and watery vapour."

Without detracting at all from the merit of Mr. Jeffreys for the clear and accurate description which he gives of the mode in which the ventilation of the lungs is carried on, and for the important bearings upon the physiology and pathology of the respiration which he points out in connexion with these facts, we cannot admit that physiologists have been guilty of the error attributed to them. The air of the breath has been experimented upon, and regarded only as affording an estimate of the average changes which must take place in a given time in the lungs, and may have been, for the sake of brevity, talked of as if it were the direct and immediate agent of arterializing the blood; but in the words (e. gr.) of Majendie, "the portion of air expired is not exactly that which was inspired immediately before, but a portion of the mass which the lungs. contained after inspiration;" and, "inspiration and expiration are intended to renew in part the considerable mass of air contained by the lungs."

The theory of animal heat adopted and illustrated by Mr. Jeffreys is that of Crawford, as modified by Lavoisier. From a consideration of the diet of the inhabitants of the tropics, he concludes that a much greater quantity of heat would be generated in their bodies, than could possibly be got rid of in the high temperatures and moist atmospheres to which they are exposed. From this he infers that the manner and intensity of