

DIGESTION 315 



permitting the putrefactive bacteria to revel in them unchecked. As 

 a matter of fact, the bile itself has little, if any, power of hindering the 

 growth of micro-organisms, although the free bile-acids are tolerably 

 active antiseptics. In suckling children it is not uncommon to see 

 the faeces white with fat. This is a less serious symptom than in 

 adults, and perhaps betokens merely that the milk in the feeding- 

 bottle is undiluted cow's milk, which is richer in fat than human 

 milk, and ought to be mixed with an equal quantity of water. 



Bidder and Schmidt found that the chyle in the thoracic 

 duct of a normal dog contained 3*2 per cent, of fat. In a dog 

 with the bile-duct ligatured the proportion fell to 0*2 per cent. 



Bile has been credited with a physical power of aiding the 

 passage of fat through membranes, and it has been inferred 

 that this has an important bearing on the absorption of fat 

 from the intestine. But the inference does not follow from 

 the statement, and the statement has been itself denied. 



On proteids bile has no digestive action, although, according 

 to Rachford, the addition of it to fresh pancreatic juice con- 

 siderably increases the proteolytic power of that secretion. 

 The addition of bile to a gastric digest causes a precipitate 

 of acid-albumin (parapeptone), albumose, and pepsin. The 

 precipitate is soluble in excess of bile, or of a solution of 

 bile-salts, but the pepsin has no longer any power of digesting 

 proteids. Part of the bile-acids and bile-mucin is also thrown 

 down by the acid of the digest. 



It has been vaguely, and almost helplessly, suggested, in the 

 laudable endeavour to find functions for the bile, that by thus pre- 

 cipitating the chyme bile prepares it for the action of the pancreatic 

 juice. But it is difficult to see how the precipitation of a substance 

 can prepare the way for its digestion, and it is doubtful whether the 

 excess of bile required to neutralize the chyme and re-dissolve the 

 precipitated proteids actually exists. The whole discussion, is, 

 indeed, an illustration of the hazard that is run in transferring with- 

 out great care the results of digestion in vitro to the normal and 

 natural processes in the alimentary canal. 



Although bile has sometimes a feebly amylolytic action, this is not 

 to be included among its specific powers, for a diastatic ferment in 

 small quantities is widely diffused in the body. 



(5) Succus entericus. This is the name given to the special 

 secretion of the small intestine, which is supposed to be a pro- 

 duct of the Lieberkiihn's crypts. In order to obtain it pure, 

 it is of course necessary to prevent admixture with the bile, 

 the pancreatic juice, and the food. This is done by dividing 



