altered just as it is in common arthritis with ulceration after death from pyæmia of only a few days' duration. The cartilage in the case referred to was ulcerated, and the joint contained pus. M. Lebert has made several careful observations, with a view to discover whether the pusglobules are actually present in the blood of the pyæmic; the result of these seems to be, that they cannot certainly be detected; even in the blood of animals that died from the effects of pus injected into their veins, the globules of pus could only once be discovered; and it seems incontestable, that in the great majority of cases they are rapidly destroyed after having entered the circulation. This throws considerable doubt on the view above noticed, that the pus-globules become arrested in the capillaries, in consequence of their size, and thus establish numerous foci of inflammation. Rokitansky also expresses his opinion very strongly against it. He considers that pyæmia occurs not uncommonly as a primitive affection; that is to say, that pus is actually formed by and in the blood itself, in consequence of certain changes in the fibrin, such as occur in the croupous crasis, which we shall afterwards notice. This supposition would account for cases occasionally met with, in which there are multiple abscesses, yet no source of purulent infection can be discovered. The more common case of consecutive pyæmia, he states, may originate in either of the three following ways. (a.) By the absorption of the serum of pus, either into the lymphatics, or into the bloodvessels directly. (b.) By the reception of pus into blood vessels which have been in any way opened, especially into those which traverse solid formations in which the mouths of the vessels are likely to be held open. (c.) Particularly by the flowing off towards the veins of pus, which has been produced in a local process (capillary phlebitis) within the vessels. We think it important to recognize the possibility of pyæmia taking place from absorption of serum alone, because it is clear that this may easily take place wherever capillary vessels are in contact with puriform exudation. The reason why it does not more often occur is, we conceive, that in a tolerably healthy state the fluid absorbed from the pus is not adequate to contaminate the mass of the blood; it undergoes certain chemical changes, and is soon eliminated as effete matter. But in a depressed state of the vital powers, the blood cannot resist and throw off the contaminating matter, and a pyogenic diathesis is esta blished. This opinion seems to be confirmed by the experiments which have been performed upon animals. Lebert found that rabbits which had serum of pus injected into their veins, did not survive much longer than those in which pus was injected entire, but that dogs showed no serious morbid symptom after the injection of serum. In the experiment performed by Mr. H. Lee, we find that dogs and asses recovered from the effects of the injection of pus, or at least were recovering when the injection was repeated. All this shows that the weaker the system, the less it is able to resist the poisonous effects of pus, or its constituent parts; and should lead us to guard, as far as possible, against the supervention of pyæmia after operations on debilitated patients. The third mode by which pus comes to be mingled with the blood is undoubtedly the most common, and is believed by Lebert to be almost the sole one. He remarks that, in the great majority of cases, some trace of inflam

mation of the veins may be discovered, and supposes that where they cannot, the veins affected are so small, or so obscured, that the source of the disease is overlooked. We believe that in such cases, pyæmia originates in either of the two other modes. The injection of pus into the living blood tends, as Lebert states, to diminish its fibrin, to destroy its globules, to alter its normal cohesion, and to precipitate a part of its fatty principles. The blood thus altered tends to form ecchymoses, capillary hemorrhages, especially in the lobules of the lungs. Rokitansky describes the bodies of those dead with pyæmia, as presenting only a brief rigor mortis, a lax and pale condition of the muscles, especially discoloration and lacerability of that of the heart, rapidly advancing putrefaction, with extensive stains from exudation. The lungs are especially the seat of dark hypostatic congestion. The coagula of the blood in the heart and large trunks are small and soft, and the inner membrane of the vessels stained. It is very intelligible how blood thus vitiated should tend to stagnate at various points of the capillary plexuses which it traverses, and to form there minute abscesses, without supposing that the vessels are actually blocked up by entire pus-globules. The obstruction is of a chemico-vital, not of a mechanical origin. The contamination of the blood when effected, is clearly of such a nature, that it determines the rapid suppuration of all exudations; there is a strong tendency to the formation of pus, a true pyogenic diathesis. Were it not for this, the formation of the multiple abscesses would not take place so quickly. The fact stated by M. Lebert is interesting, that muco-pus, the product of an inflamed mucous membrane, produces, when injected into the blood, the same effect as pus, a further proof of the identity of the corpuscles of the two fluids.

LEUCOCYTHEMIA-LEUKHEMIA.

These terms the former signifying white cell-blood, the latter, simply white blood-have been given to a condition of the circulating fluid, which is not of very common occurrence, and has only been recently discovered. The former name is the more correct, as the blood does not lose its red color, and as the prominent alteration in it is the great increase of corpuscles, resembling the white or colorless ones naturally present. When a drop of blood, drawn during life, is examined microscopically, the red corpuscles appear tolerably natural,

'In the following case, the formation of the secondary depots seems to have depended on a coagulation of the blood in certain spots, with simultaneous exudation of fibrin. A girl, aged nineteen, died after nine days' illness, having been previously in perfect health. There was purulent matter in and around several of the articulations. The lungs contained several masses, mostly about the size of a pea, and situated near the surface. Some were dark red, well-defined, and exhibited under the microscope fibrin in strands, together with numerous blood-globules, granular cells, and celloid particles. Others appeared as whitish defined masses, showing scarce any trace of fibrinous coagulum, but multitudes of well-shaped nuclei, and celloid particles, not resembling pus-globules, with some oily and granular matter. In others, again, the central part was softening down, while the outer remained firm, the central softened part never contained pus, but granular and oily matter with varying quantities of corpuscles. The most advanced presented a capsule of firm grayish indurated matter, with soft broken up contents.

and often arranged in rouleaux, leaving intermediate spaces, which are more or less crowded with the white corpuscles. It is difficult to say what is the proportion which the one set of corpuscles bear to the other. In the case which we witnessed, we should have regarded them as nearly equal, comparing mass to mass. Dr. Bennett estimates the

white as scarcely one-third the number of the red. Many of the white. corpuscles are very much larger than the natural size. They have more coarsely granular contents than the normal ones, with an interior single, double, or tripartite nucleus. The envelop and nucleus are brought into view distinctly by the action of acetic acid, which renders the granular contents transparent. Occasionally, a crescentic nucleus is to be seen in the cells, and some free nuclei are also observed between them. The blood, in fatal cases, is often found imperfectly coagulated-sometimes grumous, of a dirty brown color. The coagula, where decolorized, have not the aspect of healthy fibrin, but are of a more opaque dull yellow; and, when broken up, resemble thick creamy pus. They contain in this part very numerous white corpuscles, to which the peculiar aspect is probably due. In the case where the blood has been analyzed, the fibrin exceeded the normal amount. Perhaps this increase may be rather apparent than real, in consequence of numerous white corpuscles being included in the fibrin. The red corpuscles are invariably diminished; the solids of the serum little altered. Morbid changes are chiefly observed in the spleen, the liver, and the lymphatic glands. The spleen is often very greatly enlarged, apparently by a kind of true hypertrophy of its nuclear structure. It has, however, been found healthy. The liver is less frequently enlarged. It was so in about half the number of cases. Its texture is more or less altered. The lymphatic glands seem to have been enlarged or cancerously diseased in eleven out of nineteen cases. affection has been more often observed in males than females, in the ratio of 16:9. It seems "to be most common in adult life, and more frequent in advanced age than in youth." The respiration is often interfered with by the distension of the abdomen. Diarrhoea is a frequent symptom, vomiting is less often present. Hemorrhage, from various parts, was observed in the majority of cases, and was attended with purpura hemorrhagica in one instance. In about half the number of cases observed, dropsy was present, generally dependent on the abdominal tumors. Some febrile disturbance is not unfrequent, but not

The

to any great degree, or of long continuance. Anæmia is commonly well marked, and emaciation, in the fatal cases, is said to be extreme. There seems no reason to believe that the affection is at all connected with ague, or the malarious poison. The foregoing facts, relative to Leucocythæmia, we have taken from the memoir of Dr. Hughes Bennett, who offers the following theory of its nature: He regards the spleen, thyroid, supra-renal, pituitary, pineal, thymus, and lymphatic glands, as constituting a great glandular system, whose office it is to form the blood-corpuscles. These are for the most part thrown off from the organs mentioned, and enter the circulation as colorless nuclei, identical with the peculiar corpuscles of these glands. Sometimes, however, the nuclei proceed to cell development, and appear then as the "white corpuscles." The nuclei of these multiply by a process of division, circulate in the blood with colorless cells, and subsequently escape and become colored blood-globules. Now, "in certain hypertrophies of the lymphatic glands," Dr. Bennett believes, that "their cell-elements are multiplied to an unusual extent, and under such circumstances find their way into the blood, and constitute an increase in the number of its colorless cells. This is leucocythæmia." Our limits forbid discussion; and we can only say, that all our observations respecting the development of the red globules are entirely opposed to the view maintained by Dr. Bennett; and that we are fully convinced that, whatever action the glands referred to exert upon the fluid part of the blood, they furnish none of its corpuscular elements. The blood, we believe, forms its own floating cells, and these may, of themselves, become diseased and variously altered. Neither can we admit that the external similarity of the white granular cells in leucocythæmia to the natural white corpuscles, is a certain proof of the one being merely further developments of the other. Cells of similar aspect may have the most different properties. No other conclusions can be formed at present, as we think, than that leucocythæmia is a peculiar blood disease, whose cause and mode of origin is quite unknown.

NECRÆMIA.

This term is applied by Dr. Williams to that condition of the blood, in which it appears to be itself primarily and specially affected, and to lose its vital properties. It is, in fact, "death beginning with the blood." "The appearance of petechiae and vibices on the external surface, the occurrence of more extensive hemorrhages in internal parts, the general fluidity of the blood, and frequently its unusually dark or otherwise altered aspect, its poisonous properties, as exhibited in its deleterious operation on other animals, and its proneness to pass into decomposition, point out the blood as the first seat of disorder; and, by the failure of its natural properties and functions, as the vivifier of all structure and function, it is plainly the medium by which death begins in the body.".. "The blood, the natural source of life to the whole body, is itself dead, and spreads death, instead of life. The heart's action is faltering and feeble; the atonic vessels become the

seat of congestions, and readily permit extravasations. The brain, insufficiently stimulated after slight delirium, lapses into stupor; the medulla no longer regularly responds to the "besoin de respirer," and the respiratory movements become irregular. Muscular strength is utterly lost; offensive colliquative diarrhoea, or passive intestinal hemorrhage, often occurs; sloughy sores, or actual gangrene of various parts is very easily produced; and putrefaction commences almost as soon as ever life is extinct. The track of the superficial veins is marked by bloody stains; hypostatic congestion takes place to a great extent; the blood remains fluid, and stains the lining membrane of the vessels. Rokitansky describes the blood as often foamy, from the development of gas-of a dirty red raspberry-jelly color; its serum dark, from exuded hæmatin; and its globules swollen up by endosmosis. Coagula are either totally absent or are very soft and small. The exudations are of a dirty red-turbid, thin. There is scarce any rigor mortis; the tissue of the heart and of other organs is flaccid and softened, and stained by imbibition of the serum. Gas is quickly formed in the vessels and in the areolar tissue, giving rise to a kind of emphysema. It is very remarkable that this necræmic condition, or one closely resembling it, may be brought on by violent shocks inflicted on the nervous system, as well as by the introduction of miasmata or animal poisons into the circulation. Violent convulsions, overwhelming emotions, the shock of an amputation, a stroke of lightning, even a severe exhausting labor, are mentioned by the German pathologist as having produced this effect. More common causes, however, are malignant scarlatina and typhus, yellow fever, the plague, and the disease called glanders. It may be said, generally, that the early appearance of sinking and prostration in any fever indicates that the blood is thus seriously affected. We are ignorant what is the exact nature of the changes which take place in this condition of the blood. Probably they are more of a vital than merely chemical kind—that is, they affect the properties of the blood more than its composition. The blood-globules do not appear to be destroyed, but they circulate probably some time before death, as so many dead particles prone to be enlarged and to stagnate in the capillaries, and to part with their contained hæmatin. The fibrin is in great part destroyed; but how this comes to pass we are ignorant. We can perceive, on the whole, scarce anything more than that the powers of vital chemistry rapidly decay, and those of ordinary chemical affinity usurp their place.

CRASES OF THE BLOOD.

There are yet several morbid conditions of the blood which are scarce recognized sufficiently, at least among British Pathologists. These, Rokitansky describes as so many crases or alterations of the natural composition or mixture of the blood. They are often chronic, coming on imperceptibly, and, perhaps, scarcely noticed, until disorder begins to manifest itself in some particular organ; in other instances, probably as numerous, their development and manifestations take place rapidly,