86 INTKODTJCTTON. 



almost immediately undergoing transformation into albu- 

 men. It is also contained in the stomach and small intestines 

 during digestion. It is naturally fluid, like albumen and 

 fibrin. 



In its behavior to reagents, albuminose presents certain 

 differences from albumen. It is coagulated by alcohol and 

 many metallic salts, but is not coagulable by heat, and only 

 imperfectly by nitric acid. It is coagulated by a small quan- 

 tity of acetic acid, but the coagulum is dissolved in an excess 

 of this agent, the latter peculiarity distinguishing it from 

 caseine, which is coagulated by acetic acid in any quantity. 

 Mialhe states that albuminose is more endosmotic, or passes 

 through membranes with much greater facility than albumen, 

 which he says is absolutely non-endosmotic. This property 

 favors its introduction into the blood. 



Albuminose has its origin from the organic nitrogenized 

 elements of food, which are not only liquefied by the diges- 

 tive fluids, but undergo a catalytic transformation into this 

 substance. By virtue of its endosmotic properties, it passes 

 into the blood-vessels, and is there converted into albumen. 

 Mialhe, who first described this substance under the name 

 of albuminose, has shown that, injected into the veins of an 

 animal, it becomes assimilated, and does not pass away in 

 the urine. 1 



Caseine. 



This organic principle is peculiar to the milk, and there- 

 fore exists in the. body only during lactation. Like fibrin 

 and albumen, it is naturally fluid. 



Caseine may be easily extracted by the following process, 

 which is recommended by Robin and Yerdeil. 2 " We add 

 to the milk a few drops of acetic acid, which precipitates the 

 caseine accompanied by the fats. The coagulum separated 



1 MIALHE, Chimie Appliquee d la Physiologic, Paris, 1856, p. 126. 



2 Op. cit., tome iii., p. 341. 



