FINAL FATE OF THE BILE IN THE INTESTINAL CANAL. 325 



The bile diminishes putrefactive decomposition of the intestinal con- 

 tents, especially with a fatty diet. 



On the entrance of the strongly acid gastric contents into the duo- 

 denum, the glycocholic acid is precipitated by the acid of the stomach and 

 carries the pepsin with it. Further, the albumin and the gelatin, still 

 in solution, but not the peptones and propeptones, are precipitated by 

 the taurocholic acid, salts of the biliary acids having already been de- 

 composed by the acid of the stomach. If, however, the mixture is 

 again rendered alkaline by the pancreatic and the intestinal juice and 

 the alkali of the bases derived from the salts of the biliary acids, the 

 pancreatic ferments enter energetically into action. 



If bile enters the stomach, as, for instance, in the act of vomiting, the acid of 

 the gastric juice combines with the bases of the salts of the biliary acids. There 

 thus results principally sodium chlorid and free biliary acids. At the same time 

 the acid reaction is diminished. The biliary acids are not effective as acids 

 in gastric digestion, in place of the combined hydrochloric acid, the neutralization 

 causing also precipitation of the pepsin and the mucin. As soon, however, as the 

 wall of the stomach secretes additional acid, the pepsin is again dissolved. The 

 bile entering the stomach has a disturbing effect on gastric digestion also, by 

 causing contraction of the albuminates, as these can be peptonized only when 

 swollen. 



FINAL FATE OF THE BILE IN THE INTESTINAL CANAL. 



Of the constituents of bile, some are evacuated with the feces, while 

 others are again absorbed through the intestinal walls. 



The mucin passes into the feces unchanged. 



The biliary coloring-matters are mostly reduced in the large in- 

 testine and are partly evacuated with the feces as hydrobilirubin ; a 

 small portion of them is absorbed and finds its way into the urine as 

 urobilin. The reduction may proceed beyond the formation of hydro- 

 bilirubin to that of a colorless material, which may, however, upon ad- 

 mission of oxygen, be again oxidized to hydrobilirubin. 



Hydrobilirubin is absent from meconium, but bilirubin and biliverdin are 

 present together with an unknown red oxidation-product derived from them. 

 Therefore the process that takes place in the fetal intestine is not a reducing 

 but an oxidizing one. 



Cholesterin is in part evacuated with the feces; in part it is re- 

 duced to the form of hydrocholesterin (coprosterin), crystallizing in 

 needles. 



The biliary acids are, for the most part, again absorbed through the 

 walls of the jejunum and the ileum, and are utilized anew in the pro- 

 duction of bile. Tappeiner found them in the thoracic duct; small 

 amounts find their way from the blood into the urine. Only a small 

 portion of glycocholic acid appears unchanged in the feces. Taurocholic 

 acid, in so far as it is not absorbed, is readily decomposed in the intestine 

 by putrefactive processes into cholic acid and taurin. The former is 

 found in the feces, the latter is not infrequently absent. Cholic acid 

 is, however, in part resorbed and may again unite in the liver with 

 glycin or taurin. 



As putrefactive decomposition is absent from the fetal intestine, unchanged 

 taurocholic acid is accordingly present in the meconium Grlycocholic acid, 

 when administered, is found again in the bile from animals (< 

 mally excrete but little thereof. 



The feces certainly contain merely traces of lecithin. 



