FIBRIN. 221 



564. Fibrin, when pure, is a white elastic sub- 

 stance, insoluble in water, whether hot or cold ; but 

 soluble in acid and alkaline solutions. The muscle 

 or flesh of animals consists principally of fibrin, 

 associated with albumen and gelatine ; when dry, 

 fibrin may be easily preserved ; but when moist, like 

 albumen and gelatine, it soon begins to decompose. 

 The composition of fibrin is almost identical with that 

 of the albumen ; they consist of the same elements, 

 united together in nearly the same proportions. Fi- 

 brin, contains — 



Carbon 5456 



Hydrogen 690 



Nitrogen . . . • . . . . 1572 

 Oxygen, with '\ 



Phosphorus and [- .... 2282 

 Sulphur 3 



10,000 



565. Fibrin exists in the bodies of animals in two 

 states ; solid, and in solution : in the former state, it 

 occurs in muscle or flesh ; in the latter state, in the 

 blood ; the soluble fibrin of the blood, however, soon 

 becomes insoluble after it has been taken from the 

 body, and separates as a clot or coagulum. Blood 

 consists of water holding in solution albumen, fibrin, 

 a peculiar red coloring matter, fat, and various inor- 

 ganic substances, including chlorides of sodium and 

 potassium, carbonates, sulphates, and phosphates of 

 potash, soda, lime, and magnesia, and also a portion 

 of oxide of iron. 



19* 



