FIBRIN FROM BLOOD. 



195 



In weak muriatic acid fibrin shrinks and gives out a small 

 quantity of azotic gas ; but scarcely any portion is dissolved even 

 by boiling ; nor does the acid liquid afford any precipitate with 

 ammonia or ferrocyanate of potash. The fibrin thus treated is hard 

 and shrivelled. When repeatedly washed with water it is at last 

 converted into a gelatinous mass, which is perfectly soluble in 

 warm water. The solution reddens litmus-paper, and yields a 

 precipitate with acids as well as alkalies. Fibrin, therefore, 

 combines with muriatic acid in two proportions. The one gives 

 a neutral compound soluble in water, the other with an excess of 

 acid is insoluble, but becomes soluble by the action of pure wa- 

 ter.* 



In caustic alkali fibrin increases in bulk, becomes transparent 

 and gelatinous, and at length is completely dissolved. The solu- 

 tion is yellow with a shade of green. Acids occasion in it a pre- 

 cipitate which gradually becomes confluent. Alcohol occasions 

 a precipitate in it. Some alteration is produced upon the fibrin 

 by the alkali, but nothing in the least similar to a soap is formed.f 



Ammonia behaves with fibrin as potash does, only the action 

 is slower. 



When sulphate of soda or nitrate of potash is put into blood, 

 it is prevented from coagulating, and of course the fibrin does 

 not separate. 



Fibrin possesses exactly the characters of coagulated albumen. 



Fibrin from blood was analyzed by Gay Lussac and The- 

 nard,J by Michaelis, and more recently by Mulder Jj and Vogel.lf 

 The following table exhibits the result of these analyses : 



Gay Lussac 



and Thenard. 

 Carbon, 53-360 

 Hydrogen, 7-021 

 Azote, . 19-934 

 Oxygen, 19-685 



100000 100000 100-000 100000 100-00 



* Berzelius, Annals of Philosophy, ii. 20. f Ibid. 



{ Recherches Physico-chimiques, ii. 328. 

 Diss. de partib. constitut. sanguin. arteriosi et venosi. 

 |j Poggendorf's Annalen, xl. 255. f Jour, de Pharmacie, xxv. 587- 

 ** Varrentrapp and Will obtained 16 02 percent, of azote. Ann. der Pbarm 

 xxxix. 292. 



