366 FUNCTIONS OF THE BILE. 



The chyle of such animals is very poor in fat, is not white but transparent; the 

 faeces, however, contain much fat, and are oily. Such animals are voracious 

 (Nasse); the tissues of the body contain little fat, even when the nutrition of the 

 animals has not been much interfered with. Persons suffering from disturbances 

 of the biliary secretion, or from liver affections, ought, therefore, to abstain from 

 fatty food. 



(B.) Fresh bile contains a diastatic ferment which transforms starch 

 into sugar (Nasse, Jacobson, v. Wittich),. and also glycogen into sugar 

 (Bufalini). 



(C.) Bile excites contractions of the muscular coats of the intestine, and 

 contributes thereby to absorption. 



(1.) The bile acids act as a stimulus to the muscles of the villi, which contract 

 from time to time, so that the contents of the lymph-spaces [origins of the 

 lacteals] are emptied towards the larger lymphatics, and the villi are thus in a 

 position to absorb more (Schiff). [The villi act like numerous small pumps, and 

 expel their contents, which are prevented from returning by the presence of valves 

 in the larger lymphatics.] 



(2.) The musculature of the intestine itself seems to be excited, perhaps through 

 the agency of the plexus myentericus. In animals with a biliary fistula, and in 

 which the bile-duct is obstructed, the intestinal peristalsis is greatly diminished, 

 while the salts of the bile acids administered by the mouth cause diarrhoea and 

 vomiting (Leyden, Schulein). As contraction of the intestine aids absorption, 

 bile is also necessary in this way for the absorption of the dissolved food stuffs. 



(D.) The bile moistens the walls of the intestine, as it is copiously 

 excreted. It gives to the fseces their normal amount of water, so that 

 they can be readily evacuated. Animals with biliary fistula, or persons 

 with obstruction of the bile-ducts, are very costive. The mucus of the 

 bile aids the forward movement of the ingesta through the intestinal 

 canal. [Thus, in a certain sense, bile is a natural purgative^ 



(E.) The bile diminishes putrefactive decomposition of the intestinal 

 contents (Valentin). [Thus, it is an antiseptic.] 



(F.) When the strongly acid contents of the stomach pass into the 

 duodenum, the glycocholic acid is precipitated by the -gastric acid, and 

 carries the pepsin with it (Burkart). Some of the albumin, which has 

 been simply dissolved, but as yet not peptonised, is also precipitated, 

 but it does not seem that peptone or propeptone are precipitated by the 

 mixture of the bile acids (Maly and Emich). The bile salts are decom- 

 posed by the acid of the gastric juice. When the mixture is rendered 

 alkaline by the pancreatic juice and the alkali derived from the decom- 

 position of the bile salts, the pancreatic juice acts energetically in this 

 alkaline medium (Moleschott). 



When bile passes into the stomach, as in vomiting, the acid of the gastric juice 

 unites with the bases of the bile salts; so that sodium chloride and free bile acids 

 are formed, and the acid reaction is thereby somewhat diminished. The bile 



