328 DIGESTION. 



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 recent dis- 

 coveries have shown that 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 colour, a strongly 

 bitter taste, and when fresh with a scarcely perceptible 

 odour ; it has a neutral or slightly alkaline re -action, and 

 its specific gravity is about 1020. Its colour and degree 

 of consistence vary much, apparently independent of 

 disease ; but, as a rule, it becomes gradually more deeply 

 coloured 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 colour, and more bitter taste, mainly from its 

 greater degree of concentration, on account of partial 

 absorption of its water, but partly also from being mixed 

 with mucus. 



The following analysis is by Frerichs : 



Composition of Human Bile. 



Water . t . . ; ..: *. . . 859-2 

 Solids 140-8 



[,ooo-o 



a, small branch of an interlobular hepatic duct ; b, smallest biliary ducts ; 

 c, portions of the cellular part of the lobule in which the cells are seen 

 within tubes which communicate with the finest ducts. 



