286 HANDBOOK OF PHYSIOLOGY. 



consisting of clear, colorless fluid, instead of being opaque and white, as 

 they ordinarily are, after feeding. 



(b.) It is probable, also, that the moistening of the mucous membrane 

 of the intestines by bile facilitates absorption of fatty matters through it. 



(c.) The bile, like the gastric fluid, has a considerable antiseptic 

 power, and may serve to prevent the decomposition of food during the 

 time of its sojourn in the intestines. Experiments show that the con- 

 tents of the intestines are much more foetid after the common bile-duct 

 has been tied than at other times : moreover, it is found that the mix- 

 ture of bile with a fermenting fluid stops or spoils the process of fermen- 

 tation. 



(d.) The bile has also been considered to act as a natural purgative, 

 by promoting an increased secretion of the intestinal glands, and by 

 stimulating the intestines to the propulsion of their contents. This 

 view receives support from the constipation which ordinarily exists in 

 jaundice, from the diarrhoea which accompanies excessive secretion of 

 bile, and from the purgative properties of ox-gall. 



(e.) The bile appears to have the power of precipitating the gastric 

 parapeptones and peptones, together with the pepsin, which is mixed up 

 with them, as soon as the contents of the stomach meet it in the duode- 

 num. The purpose of this operation is probably both to delay any 

 change in the parapeptones until the pancreatic juice can act upon them, 

 and also to prevent the pepsin from exercising its solvent action on the 

 ferments of the pancreatic juice. 



II. BLOOD-ELABOKATIOX. 



The secretion of bile, as already observed, is only one of the purposes 

 fulfilled by the liver. Another very important function appears to be 

 that of so acting upon certain constituents of the blood passing through 

 it, as to render some of them capable of assimilation with the blood 

 generally, and to prepare others for being duly eliminated in the process 

 of respiration. It appears that the peptones, conveyed from the alimen- 

 tary canal by the blood of the portal vein, require to be submitted to 

 the influence of the liver before they can be assimilated by the blood; 

 for if such albuminous matter is injected into the jugular vein, it 

 speedily appears in the urine ; but if introduced into the portal vein, 

 and thus allowed to traverse the liver, it is no longer ejected as a foreign 

 substance, but is incorporated with the albuminous part of the blood. 



Glycogenic Function. 



One of the chief uses of the liver in connection with that elaboration 

 of the blood is known as its glycogenic function. The important fact 

 that the liver normally forms glucose, or a substance readily convertible 



