THE BILE. 



323 



Biliary acids combined 



Bilin 



with alkalies j 

 Fat 



Cholesterin 



Mucus and colouring matters . 



Salts . 



91-5 

 9-2 

 2-6 



29-8 

 77 



140-3 



The Bilin or biliary matter when freed by ether from the 

 fat with which it is combined, is a resinoid substance, solu- 

 ble in water, alcohol, and alkaline solutions, and giving to 

 the watery solution the taste and general character of bile. 

 It is a compound 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. Be- 

 sides the ordinary saponifiable fats, there is a small quantity 

 of cholesterin (p. 1 1 ), which, with the other free fats, is 

 probably held in solution by the tauro-cholate of soda. 



A peculiar substance, which Dr. Flint has discovered in 

 the fseces, and named stercorin (p. 342), is closely allied 

 to cholesterin ; and Dr. Flint Fig. 91.* 



believes that while one great 

 function of the liver is to ex- 

 crete cholesterin from the 

 blood, as the kidney excretes 

 urea, the stercorin of fasces 

 is the modified form in which 

 cholesterin finally leaves the 

 body. Ten grains and a half 

 of stercorin, he reckons, are 

 excreted daily. 



The colouring matter of thejbile has not yet been obtained 

 pure, owing to the facility with which it is decomposed. 

 It occasionally deposits itself in the gall-bladder as a 



Fig. 91. Crystalline scales of cholesterin. 



y 2 



