THE BILE. 259 



Functions of the Liver. 



The Secretion of Bile is the most obvious, and one of the 

 chief functions which the liver has to perform ; but, as will be 

 presently shown, it is not the only one ; for important changes 

 are effected in certain constituents of the blood in its transit 

 through this gland, whereby they are rendered more fit for 

 their subsequent purposes in the animal economy. 



The Bile. 



Composition of the Bile. The bile is a somewhat viscid fluid, 

 of a yellow or greenish-yellow color, a strongly bitter taste, 

 and when fresh with a scarcely perceptible odor ; it has a 

 neutral or slightly alkaline reaction, and its specific gravity is 

 about 1020. Its color and degree of consistence vary much, 

 apparently independent of disease ; but, as a rule, it becomes 

 gradually more deeply colored and thicker as it advances 

 along its ducts, or when it remains long in the gall-bladder, 

 wherein, at the same time, it becomes more viscid and ropy, 

 of a darker color, and more bitter taste, mainly from its 

 greater degree of concentration, on account of partial absorp- 

 tion of its water, but partly also from being mixed with mucus. 



The following analysis is by Frerichs : 



Composition of Human Bile. 



Water, 859.2 



Solids, 140.8 



1000.0 



Biliary acids combined "I D . r nl K 



with alkalies, } Bllin ' * 



Fat, 9.2 



Cholesterin, 2.6 



Mucus and coloring matters, .... 29.8 

 Salts, 7.7 



140.S 



The bilin or biliary matter when freed by ether from the fat 

 with which it is combined, is a resinoid substance, soluble in 

 water, alcohol, and alkaline solutions, and giving to the watery 

 solution the taste and general character of bile. It is a com- 

 pound of soda, with two resinous acids, named glycocholic 

 and taurocholic acids. The -former consists of cholic acid 

 conjugated with glycin (or sugar of gelatin), the latter of the 

 same acid conjugated with taurin. 



Fatty substances are found in variable proportions. Besides 



