HANDBOOK FOR BIO-CHEMICAL LABORATORY. 15 



but readily soluble in alkalies Xa 3 C0 2 , Na 2 HP0 4 , as well as 

 dilute hydrochloric acid. It does not coalgulate on applying 

 heat to its solutions. 



Albuminate (Acid). 



Preparation. Digest the white of two eggs with hydro- 

 chloric acid (0.5$), and let it stand or apply gentle heat ; then 

 dilute with twice its volume of water. Collect the precipi- 

 tate, dissolve it in hot water, and carefully neutralize the solu- 

 tion with Na 2 C0 3 ; finally wash well with water, and the prod- 

 uct will be pure acid albuininate. 



Fibrin, 



Preparation. Whip freshly-drawn ox-blood with a bunch 

 of twigs ; the fibrin adheres to the twigs and entangles but a 

 few blood-corpuscles. The mass is washed for a long time in 

 a stream of ruuning water until nearly white, and then with a 

 5$ common salt solution, and again with water. When free 

 from NaCl extract with alcohol and then with ether, and pre- 

 serve in a solution of equal parts glycerine and water. 



Properties. Fibrin is soluble with difficulty in a 5-10$ 

 common salt or -saltpetre solution or similar solutions of 

 MgS0 4 or other neutral salts. In the presence of enzymes or 

 by putrefaction it may dissolve. It is insoluble in water, alco- 

 hol, or ether. Fibrin decomposes hydrogen peroxide. Solu- 

 tions of fibrin are precipitated by lead acetate, copper sulphate, 

 and mercuric chloride. Weak HOI (0.2$) causes fibrin to 

 swell up into a transparent jelly, while stronger acids dissolve 

 it in a time with the formation of acid albumin or syntonin 

 and albumoses. 



