Volume 1

A text-book of human physiology : including histology and microscopical anatomy : with special reference to the requirements of practical medicine / by L. Landois ; translated from the seventh German edition, with additions, by William Stirling.

Date:: 1891

Credit: A text-book of human physiology : including histology and microscopical anatomy : with special reference to the requirements of practical medicine / by L. Landois ; translated from the seventh German edition, with additions, by William Stirling. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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$nature of a ferment, although they use the term for convenience. It is quite certain that fibrin may be formed when no fibrino-plastin is present, coagulation being caused by the addition of calcic chloride or casein prepared in a special way. One of the conditions necessary for the action of fibrin-ferment on fibrinogen seems to be the presence of neutral salts. If the latter be completely removed the formation of fibrin does not take place. Lime salts seem to be in some way essential to the process, e.g., calcic srdphate, Avhile others attach importance to the jiresence of NaCL] [The mam drift of the foregoing evidence points to the presence of one proteiil —fibrinogen—-which exists dissoh^ed m the blood-plasma, and which under certain circumstances yields fibrin. In shed blood this act seems to be determined by a ferment, perhaps derived from the disintegration of colourless corpuscles (and blood-platelets ?), which occurs when blood is shed.] [It must not be forgotten that the presence of certain salts seems necessary to the act of coagulation. As the question at present stands, three factors are recog- nised in the equation :— (1) A coagulable proteid (fibrinogen). (2) A ferment. (3) Certain salts. Up till recently the first two have attracted the greatest amount of attention, but that the third factor is also an important one is shown by the above-mentioned researches.] 30. SOURCE OF THE FIBRIN-FACTORS—Al. Schmidt maintains that all the three substances out of which fibrin, according to him, is formed arise from the breaking up of colour- less blood-corpuscles. lu the blood of man and mammals fibrinogen exists dissolved in the circulating blood as a dissolution-product of the retrogressive changes of the white corpuscles. Plasma contains cHssolved fibrinogen and .serum-albumin. The circulating blood is very rich in colourless blood-col'[)Uscles—much richer, indeed, than was formerly supposed. As soon as blood is shed from an artery, enormous numbers of the colourless corpuscles arc dissolved— according to Al. Schmidt, 71‘7 per cent, (horse). First the body of the cell disappears, and then the nucleus. The products of their dissolution are dissolved in the plasma, and one of these products is jihrino-'plaslin. At the same time the fibrin-ferment is also produced, so that it would seem not to exist in the intact blood-corpuscles. Fibriuo-plastiu and fibrin-ferment are also produced by the “ transition forms of blood-corpuscles, i.e., those forms which are intermediate between the red and the white corpuscles. They seem to break up immediate!}’ after blood is shed. The Mood-plates (p. 19) are also, probably, sources of these substances. The leucocytes have difl’erent degrees of resistance ; those of the lymph and chyle are more resistant than those of the blood, and amongst the latter themselves there are various degrees {Eeyl). In amphibians and birds the red nucleated corpuscles rapidly break up after blood is shed, and yield the substance or substances which form fibrin. Al. Schmidt convinced himself that in these animals fibrinogen is originally a constituent of the blood-corpuscles. It is clear, therefore, according to Schmidt’s view, that as soon as the blood-corpuscles, white or red, are dissolved, the fibrin-factors pass into solution, and the lormation of fibrin by the interaction of the three substances will ensue. If a large number of leucocytes be introduced into the cii’culation of an animal, the leucocytes are_dissolved in great numbers in the blood, so that death takes place by diffuse coagulation. Should the animal survive the immediate danger of death, the blood, owing to the want of leucocytes, is completely incapable of coagulating {Oroth). _ , j • [And. Buchanan thought that the potential element of his “washed blood-clot resided in the colourless corpuscles, “primary cells or vesicles.” He, like Schmidt, found that the bufl'y coat of horses’ blood, which is very rich in white corpuscles, produced coagulation rajiidly. Buchanan compared the action of his washed clot to that of rennet in coagulating milk.] Pathological.—Al. Schmidt and his pupils have shown that some lerinent, probably derived from the dissolution of colourless corpuscles, is found in circulating blood, and that it is nioie abundant in venous than in arterial blood, while it is most abundant in shed blood. It is specially remarkable that in septic fever the amount of ferment in blood may increase to such an extent as to permit the occurrence of spontaneous coagulation (thrombosis), which may even produce death {Arn. Kohler). In febrile cases generally, the amount of ferment is somewhat more abundant {Edelberg and Birk). After the injection of ichor into the blood an enormous$