356 THE ANTISEPTIC ACTION OF THE BILE. [BOOK II. 



fatty acids in solution and capable of forming a perfect emulsion 

 with the neutral fats. The process is one in which soaps are pro- 

 duced through the decomposition of the alkaline salts of the bile 

 acids by the free fatty acids. As a matter of fact, the bile in the 

 intestine finds itself in contact with fatty acids which have been 

 liberated from the neutral fats by the fat-decomposing enzyme of 

 the pancreatic juice, and all the conditions are present which are 

 requisite to confer on the bile an emulsionising action. How far 

 this action is important in the mechanism of the absorption of fats 

 will be further considered when that subject is being treated of in 

 detail. 



But the action of the bile on the fats is not limited to the 

 formation of soaps with the free fatty acids Neurneister 1 points 

 out that solutions of the cholates possess the power, when gently 

 heated, of dissolving the insoluble soaps of calcium and magnesium, 

 compounds which doubtless occur in the intestine. In considering 

 the absorption of fats, we shall also discuss the supposed influence 

 of the bile in aiding the passage of fats through membranes. 



The Antiseptic and Laxative Actions of the Bile. 



It is impossible to make observations on dogs with biliary fistulse 

 without being struck by the peculiar fcetor of the faeces, which 

 reminds one of the foetid smell emanating from vats in which 

 skeletons are macerating. The clay-coloured faeces of human beings 

 with biliary fistulse, or suffering from jaundice depending on a 

 complete obstruction to the flow of bile in the intestine, almost 

 invariably present somewhat of the same peculiar fcetor. These 

 facts naturally led physiologists (Bidder and Schmidt) and physicians 

 to ascribe to the bile an antiseptic action on the contents of the 

 intestine. That the bile is in any sense an antiseptic has, however, 

 been denied by some, inasmuch as it is a liquid which when ex- 

 posed to air rapidly decomposes ; the experiments of Sherrington 2 

 and of Copeman and Winston 3 have shewn, moreover, that micro- 

 organisms, of the most diverse kinds, develope perfectly in culture 

 media to which bile has been added. 



It has already been said that the clay-coloured faeces of animals 

 with biliary fistulae, as well as of human subjects with obstruction of 

 the common bile-duct, when fed upon a mixed diet, contain undigested 

 fat. It is, indeed, this unabsorbed fat, which amounts to 11 or 13 per 

 cent, of the weight of the fasces, which is the chief cause of the clay- 

 coloured appearance which they present. It has been found, that 

 when an animal is fed upon a diet in which flesh is absent the putrid 



1 Neumeister, Lehrbuch d. phys. Chemie, 1893, p. 178. 



2 C. J. Sherrington, Journal of Pathology and Bacteriology, Feb. 1893. 



3 Copeman and Winston, op. tit., Journ. of Physiology, Vol. x. (1889), p. 226. 

 On this matter compare the experiments of Limbourg, Zeitschrift f. phys. Chemie, 

 Vol. xm. p. 196. 



