DIGESTION. 195 



proteins or on fats directly. But indirectly and by virtue of the bile salts it 

 contains, it plays an important part in increasing the action of the pancreatic 

 enzymes. Thus the amylolytic or amyloclastic power of the pancreatic 

 juice is almost doubled and the same is true for its proteoclastic power, 

 while its lipoclastic or fat-splitting power is tripled. 



The bile salts also dissolve insoluble soaps which may be formed during 

 digestion and thus favors the digestion of fat. If it be excluded from the 

 intestine there is found in the feces from 22 to 58 per cent, of the ingested 

 fats. At the same time the chyle, instead of presenting the usual white 

 creamy appearance, is thin and slightly yellow. The manner in which the 

 bile promotes fat digestion is yet a subject of investigation. If all the fat 

 is converted into fat acids and glycerin, with the formation of soaps, as 

 seems probable, the action of the bile becomes more apparent from the fact, 

 already stated, that it dissolves and holds in solution the soaps so formed 

 which would be necessary to their absorption by the epithelial cells. This 

 action has been attributed to the presence of the bile salts. As an aid to 

 digestion the bile has been regarded as important, for the reason that its 

 entrance into the intestine is attended by a neutralization and precipitation 

 of the proteins which have not been fully digested and are yet in the stage 

 of acid-albumin. In this way gastric digestion is arrested and the foods are 

 prepared for intestinal digestion. 



Though bile possesses no antiseptic properties outside the body, itself 

 undergoing putrefactive changes very rapidly, it has been believed that in 

 the intestine it in some way prevents or retards putrefactive changes in the 

 food. There can be no doubt that if the bile is prevented from entering 

 the intestine there is an increase in the formation of gases and other products 

 which impart to the feces certain characteristics which are indicative of 

 putrefaction. As to the manner in which bile retards this process nothing 

 definite can be stated. It has been supposed to be a stimulant to the 

 peristaltic movements of the intestine, inasmuch as these movements 

 diminish when bile is diverted from the intestine. 



Though no definite nor specific action on any of the different classes of 

 food principles can be attributed to the bile, there is abundant evidence to 

 show that its presence in the alimentary canal during digestion is essential 

 to the maintenance of the nutrition of the body. That the bile as a whole, 

 or at least part of its constituents, favorably influences digestion and general 

 nutrition is evident from the phenomena which follow its total exclusion 

 from the intestine, as when the common bile-duct is ligated and a fistula of 

 the gall-bladder is established. The following phenomena were observed 

 in a young dog so prepared by Professor Flint. During the first five days 

 succeeding the operation the abdomen was tumid and there was some rum- 

 bling in the bowels. Though the animal ate every day, the discharge of 

 fecal matter became infrequent, the matter passed being grayish in color and 

 highly offensive. After two weeks the alvine discharges took place three 

 and four times daily. For four days the weight remained normal ; afterward 

 it began to diminish, and from this time the animal continued to lose strength 

 and weight until its death, thirty-eight days after the operation. Ten days 

 after the operation the appetite, which had been very good, increased, but 

 did not become ravenous until a few days before death. The animal usually 



