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PATHOLOGY OF THE BLOOD-HYPERFIBRINOSIS.

of hyperfibrinosis are most various-thus inflammations, especially of such organs as are freely supplied with lymphatics-lung, liver, &c.-Virchow has shown, vastly augment the amount of fibrin, even to the proportion of 13.3, while phrenitis scarcely produces any such effect. Rheumatic fever is well known to produce similar increase, because it is an inflammation of parts freely supplied with lymphatics-or, as it occurs to me, the fibrin is not removed from the blood to repair muscular waste, almost complete immobility existing. Disease produced by animal poisons, as the eruptive fevers, are often attended by this increase of fibrin in their accession.

Hyperfibrinosis may be produced artificially by making animals breathe more oxygen while at rest; but if active exercise be taken, the excess is got rid of. This and other facts have led Dr. Gairdner, Professor of Medicine in Glasgow University, to believe that, as regards the blood, "oxygenation and fibrillation are identical.' Its more frequent deposition, as valvular clots on the left side of the heart, is explained by these facts. The occurrence of rigors in the beginning of inflammations has been explained by the abstraction of oxygen to convert albumen into fibrin producing a loss of heat; and their recurrence, if suppuration follows, to still more of that element being required to form the more highly oxidised compound which pus contains. Fibrin, but of an inferior character, is abundantly produced in the blood in tuberculosis and cancer, as will be hereafter mentioned. Neutral salts, which preserve the fluidity of the fibrin, and such oxidising agents as chlorate of potash, or permanganate of potash, which is well worthy of trial, are indicated in cases of hyperfibrinosis.

To the condition in which the proportion of fibrin is decreased, or in which it is even absent, the term hypinosis or afibrinosis is applied; but as such is seldom the only pathological change, its separate consideration may

be scarcely necessary. Wedl regards it as identical with the state he describes as "albuminosis." The blood scarcely clots owing to the superabundance of ammonia, for Simon always found the blood alkaline, and there could be found no fibrin but carbonate of ammonia in one case of putrid fever. It is frequently a result of the introduction of the paludal or malarious fever poison, having been lowered to the proportion of 0.9 in cases where recovery afterwards took place. Deficiency of fibrin has been also discovered in cases of hemorrhagic diathesis-a peculiarity which is often hereditarily transmitted—typhus, mania, and some other diseases, especially those which impede respiratory action; and likewise in that morbid state, cyanosis, which is usually congenital, the blood is almost entirely venous and contains fibrin very scantily.

As to the morbid variations which the proportion of salts undergoes, we know but little. Their proportion has been found very low in inflammations, thereby tending to produce the coagulation of the blood within the vessels which is characteristic of that process, and greatly increased in typhus-producing the opposite effect. Scurvy, and perhaps purpura, are due, according to Dr. Aldridge-and the remark was confirmed by Gurrod—to a deficiency of potash salts; hence the efficacy of uncooked vegetables, lime juice, fresh meat, &c., in preventing or relieving those diseases. My former pupil, Dr. D. Walker, of the late Arctic expedition, informs me that the juice or blood of meat seemed to possess, mainly, the prophylactic properties. It was, therefore, always given underdone. [See page 55, and also my "Lectures on Public Health," where I have also discussed the connexion of a want of phosphorus and scurvy.] This theory of deficiency of potash salts has been much opposed, and is at variance with the valuable analyses of Mr. Busk, who found the salts increased from 6-8 (the normal proportion) to 9.5, 10·9, and 11·5,

in 3 cases of scurvy. The extravasation of blood which occurs is generally attributed to a thin state of the blood (the hematin of which, according to some, is alone effused), but may be due to some weakened or illnourished state of the capillary vessels. The earthy salts have been found diminished in proportion in cases of rachitis; and in old age they have been supposed to be removed from the bones and carried to the vascular and fibrous tissues, producing calcareous degeneration and chronic rheumatism, the pain of which is thus accounted for.

The effects resulting from increasing the specific gravity of blood by adding to it crystalloids-such as saline substances and sugars, or bodies that act like crystalloids, specially alcohol-have been demonstrated by Dr. Richardson, of London, who maintains that cataract arises from increased specific gravity of blood, and that cirrhosis of the liver is purely a physical change produced from a similar modification of blood.

Fatty matter may be excess in the blood, and is denoted by the opalescence of the serum, and has been said to attain the proportion of 117. This condition has been found to precede the pathological state termed fatty degeneration, which will be presently noticed. The normal amount of fat in the blood is said to be decreased in phthisis.

Cholemia, or the condition of the blood in jaundice, may result from-1. A superabundant formation of the materials of bile, or their being received into the blood in excess. 2. A failure in the action of the bile-secreting cells of the liver. 3. An obstruction to the discharge of the bile through its ducts, followed by the re-absorption of some of its constituents into the circulating fluid. The serum, buffy coat if formed, all the secretions, and many of the tissues become stained by the biliphain. Cholesterin, cholic acid, leucin, and tyrosin have been detected in the blood. The kidney,

for a long time, staves off injurious effect, for by excreting urophæin, purpurin, and other highly carbonaceous materials, its office is somewhat vicarious to the liver. Much more formidable symptoms follow the nonsecretion than the reabsorption of bile. The remarks on the functions of the liver we have previously made, may be now advantageously referred to.

Another retained matter, urea, gives rise to that very frequent state of blood, uremia-which has been before briefly discussed when treating of the physiology and pathology of the kidney-the organ by defect of which its retention ensues. Glycemia, or the increase of sugar in blood, has been also described in the same section. Again, evidence is every day accumulating that gout, rheumatism, cutaneous eruptions, and many other diseases are due to failure of some excretion from the blood.

Pyemia was the name applied to the entrance and diffusion of pus through the blood; but as white bloodcells and pus-cells are indistinguishable, it is now very generally believed they have been mistaken for each other. In this way were accounted for the disappearance of abscesses, their metastatic discharge by the kidney or bowels, or the sudden deposit of pus in the lungs, liver, joints, and other places. However, from the size of the cells, pus, as such, can never be absorbed, but it may disappear by either of the following methods-the liquor puris may be absorbed and the cells may concrete into an almost solid mass of cheesy matter, found in dried up abscesses, strumous glands, and tubercle, which, according to Reinhardt, is in this way formed, and is always the result of inflammatory action. The second method in which that fluid may be removed is by fatty degeneration, in which the pus cells break up, and a fatty, saccharine, and albuminous fluid, aptly compared to milk, results, and which may be afterwards completely absorbed. The veins have been thought to be so ready a channel for the transmission of pus, that phlebitis and

pyemia have been considered almost synonymous terms, and the lymphatics were also supposed to carry that fluid; but the fact of mineral substances used in tattooing the arm, and the matters of cancer and syphilis being arrested in their glands, renders this latter hypothesis improbable. When the so-called pus is found in veins, it always lies in the centre of blood-clots.

I shall quote the opinions of Morgagni-an ancient but surprisingly accurate pathologist. In his book, "De Sedibus et Causis Morborum," he says wounds and blows upon the head "give origin to the generation of a much more copious pus than what is carried thither; which generation is shown by those rigors and horrors. And by this means we may also conceive how it is that much more pus is frequently found in the viscera and cavities of the bodies than a small wound could have produced."

The lymphatic glands, or the organs which make the white-cells, are known to increase much during pregnancy, and they fill the blood with numerous white-cells or much fibrin, a fact which may account for the readiness with which the then so-called pyemia is excited, and for the fatality of scarlatina and other zymotic poisons if they attack women in this condition. Suppuration in joints, serous cavities, and other distant places in cases of phlebitis, seems to be the combined result of local inflammation and abundance of corpuscular fibrin in the blood.

Thrombosis is the name applied by Virchow to that condition in which clots, often with a puriform interior, form in the heart or blood-vessels; and the portions of these which may become detached, and block up other vessels, are named emboli. These emboli may entirely occlude the vessel; or if they have entered the pulmonary artery, as they most frequently do, they may cause asphyxia, or may be impelled onwards into the capillaries of the lungs, and there excite limited spots of in