256 DIGESTION. [CHAP. xxv. 



that if fresh bile be deprived of its mucus, the bilin will continue 

 unchanged for a considerable time. 



Among the saline constituents of the bile, Berzelius enumerates 

 the following : Oleate, margarate, and stearate of soda, with 

 chloride of sodium, sulphate, phosphate and lactate of soda, and 

 phosphate of lime. 



Such is the view of the constitution of bile put forward by the 

 celebrated Berzelius, and sanctioned by Mulder. Berzelius remarks 

 that the views which regard bile as a solution of soap, are so far 

 correct, as it contains a small quantity of soap dissolved in it. 



The most recent analysis of bile is that by Strecker, made under 

 the direction of Liebig, who denies the accuracy of Berzelius' s view, 

 adopting rather that of Dema^ay, Dumas, Liebig, and others, that 

 bile is a solution of a salt of soda with an organic substance of an acid 

 nature, which is not a single acid, but a mixture of a nitrogenous 

 acid free from sulphur (cholic acid), with a second acid, containing 

 both sulphur and nitrogen (choleic acid.) 



Use of the Bile, and Functions of the Liver. From the anatomy 

 of the biliary organs, as well as from the chemistry of the bile, we 

 learn that, before the venous blood of the intestinal canal and the 

 spleen is allowed to reach the right side of the heart, a fluid very 

 rich in carbon is eliminated from it, and poured into the duodenum. 

 The following questions suggest themselves respecting the uses of 

 this fluid ; viz., is the bile simply an excrement, like the urine ? or 

 is it an excrement which also serves some ulterior purpose, such as 

 aiding the solution or digestion of the food in the bowels ? 



The doctrine that the secretion of bile by the liver, is merely a 

 mode of eliminating carbon from the system, is strongly opposed 

 by the fact, that in all the vertebrate classes the bile, instead of 

 being carried out of the system by the most direct channel, as the 

 urine is, is made to pass through nearly the whole intestinal canal, 

 and to mingle freely with its contents. Moreover, the point at 

 which it enters the bowel, always bears a pretty definite relation 

 to that at which the pancreatic fluid is poured into it. Either 

 these fluids enter the bowel together through a common opening, 

 as in man, or the bile is poured in above, never below, the point of 

 opening of the pancreatic duct. 



These are capital facts, which must be accounted for by an 

 adequate theory of the uses of the bile. They indicate that the 

 bile has some use in promoting the changes of the food in the 

 intestines, or in contributing to the general process of nutrition in 

 some other way. It is well known that an obstacle to the free 



