FIBRIN. 255 



small, less elastic, and not particularly fibrous, lumps. The typical 

 fibrous and elastic white fibrin, after washing, stands, in regard to its 

 solubility, close to the coagulated proteins. It is insoluble in water, 

 alcohol, or ether. It expands in hydrochloric acid of 1 p. m., as, also in 

 caustic potash or soda of 1 p. m., to a gelatinous mass, which dissolves at 

 the ordinary temperature only after several days; but at the temperature 

 of the body it dissolves more readily, although still slowly. Fibrin may 

 be dissolved by dilute salt solutions, after a long time, at the ordinary 

 temperature, or much more readily at 40 C. ; and this solution takes place, 

 according to ARTHUS and HUBERT and also DASTRE/ without the aid 

 of micro-organisms. This action is due to proteolytic enzymes car- 

 ried down by the fibrin or enclosed within the leucocytes (RuLOT 2 ). 

 According to GREEN and DASTRE 3 two globulins are formed in the solu- 

 tion of fibrin in neutral salt solution, and according to RULOT also pro- 

 teoses (and peptones) on the solution of fibrin containing leucocytes. 

 Fibrin, like fibrinogen, decomposes hydrogen peroxide, due to a con- 

 tamination with catalases, but this property is destroyed by heating or 

 by the action of alcohol. 



What has been said of the solubility of fibrin relates only to the typical 

 fibrin obtained from the arterial blood of oxen or man by whipping 

 and washing first with water and with common salt solution, and then 

 with water again. The blood of various kinds of animals yields fibrin 

 with somewhat different properties, and according to FERMI 4 pig-fibrin 

 dissolves much more readily than ox-fibrin in hydrochloric acid of 5 p. m. 

 Fibrins of varying purity or originating from blood from different parts 

 of the body have unlike solubilities. 



The fibrin obtained by beating the blood, and purified as above 

 described, is always contaminated by secluded blood-corpuscles or 

 remains thereof, and also by lymphoid cells. It can be obtained pure 

 only from filtered plasma or filtered transudates. For the preparation 

 of pure fibrin, as well as for the quantitative estimation of it, the spon- 

 taneously coagulating liquid is at once, or the non-spontaneously coagu- 

 lating liquid only after the addition of blood-serum or fibrin ferment, 

 thoroughly beaten with a whale-bone, and the separated coagulum is 

 washed first in water and then with a 5-per cent common salt solution, 

 and again with water, and finally extracted with alcohol and ether. If 

 the fibrin is allowed to stand for some time in contact with the Hood 

 from which it was formed, it partly dissolves (fibrinolysis DASTRE 5 ). 

 This fibrinolysis must be prevented in the exact quantitative estimation 



1 Arthus and Hubert, Arch, de Physiol. (5) 5; Dastre, ibid., (5) 7. 



2 Arch, intern, de Physiol., 1. 



3 Green, Journ. of Physiol., 8; Dastre, 1. c. 



4 Zeit^chr. f. Biologic, 28. 



6 Archives, de Physiol. (5), 5 and 6. 



