BILE OF THE OX. 117 



made by the union of two distinct resinoid acids with the 

 alkali soda. These acids (the glycocholic and tanrocholic) both 

 contain nitrogen. One of them, the taurocholic acid, contains 

 sulphur, which element does not exist in the other, or glyco- 

 cholic. In ox-bile, besides mucus derived from the gall-blad- 

 der, there are also contained minute quantities of cholesterine, 

 and a small proportion of stearic, oleic, and lactic acids, com- 

 bined with potash and ammonia. Besides these constituents, 

 a peculiar colouring matter exists, joined to an alkaline base. 

 There is also a body recently announced, to which the name 

 lecithin has been applied, known by affording oleophosphoric 

 acid when boiled with hydrate of baryta. 



The important views recently brought forward as to the 

 power of the liver to convert various proximate principles into 

 sugar have already obtained a sufficient notice when the bile of 

 the horse was spoken of (p. 64). 



The quantity of bile secreted in a given time is very large 

 as compared with the average amount of the daily excretion 

 by the rectum. Hence it is obvious that the bile is decom- 

 posed within the alimentary canal, and reabsorbed in one form 

 or another, while but a small proportion of the whole product 

 of the liver is mingled with that excretion. 



The bile is conveyed from the liver to the duodenum by the 

 great bile-ducts. In the ox, as in man, there is a gall-bladder 

 a piece of the biliary apparatus which does not exist in the 

 horse. This receptacle of the bile lies on the concave surface 

 of the liver. It is lined by a prolongation of the mucous mem- 

 brane, which, extending from the intestine through the great 

 duct, reaches the interior of the gall-bladder. External to this 

 is an areolar coat, and over all a peritoneal coat, by which the 

 gall-bladder is made to cling close to the surface of the liver. 

 In rare cases the gall-bladder is entirely covered with peri- 

 toneum, the lamina from either side being united into a dupli- 



