220 PHYSIOLOGY CHAP. 



usual. It was, however, found that defaecation was infrequent 

 and difficult ; that the faeces assumed a fatty appearance, grey or 

 brown in colour, and had a putrid odour ; that much gas was 

 developed in the intestine and produced fetid flatulence ; and that 

 the expired air had a bad smell, both in fasting and after a meal. 

 In a word, dogs with a biliary fistula suffered owing to intestinal 

 acholia from exaggerated putrefaction in the intestine, which 

 caused progressive emaciation, and death. The autopsy showed 

 no particular lesion of the organs, such as would induce a fatal 

 result. 



These observations gave rise to the conjecture that bile normally 

 exercises an anti-putrefactive action on nitrogenous food-stuffs. 

 But bile in itself is an effusion, that putrefies readily with much 

 evolution of gas (Giannuzzi and G. Bufalini) and development of 

 indole from the decomposition of the mucin (Ernest). We know, 

 however, that the bile salts are decomposed in the duodenum, 

 and that the free taurocholic acid actually exercises a certain anti- 

 putrefactive power (Lindeberger, Gley and Lambling), as does 

 also cholalic acid, which is a cleavage product of the former 

 (Bufalini, Albertoni, Limbourg). 



The anti-putrefactive action of bile can also (it seems to us) 

 be regarded as an indirect effect of the excitatory action that it 

 exerts, more particularly by its free acids, upon the muscle fibres 

 of the intestine, increasing the peristaltic movements that serve to 

 expel the faeces. This is proved by the fact that intestinal acholia 

 produces constipation, on which the alimentary residues remain 

 longer in the bowel, and reach a more advanced stage of putre- 

 faction. 



Lastly, the fact that in intestinal acholia there is almost always 

 a considerable quantity of fat that has escaped absorption, shows 

 that bile, besides favouring the digestion of fats, facilitates their 

 absorption. This fact depends essentially on the property of the 

 bile acids of dissolving the fa.tty acids liberated by the lipolytic 

 action of the steapsin. According to Marcet (1858), whose experi- 

 ments were subsequently confirmed by Moore and Rockwood, bile 

 acids, at body temperature, dissolve fatty acids to the amount of 

 2-6 per cent. These authors hold that the fatty acids are absorbed 

 in this state, and not in the form of emulsion. We shall return 

 to this interesting point. Meantime it may be added that accord- 

 ing to C. Voit, Rohmann, Fr. Miiller, the faeces in jaundice contain 

 55-78 per cent of the fats ingested, while in normal individuals 

 they contain only 7-10 per cent. The greater part of the fat in 

 the faeces is present in the form of free fatty acids, or combined 

 as soaps with lime and magnesia. Neurneister explains the 

 influence of bile on fat absorption by assuming that it is capable 

 of dissolving these otherwise insoluble soaps ; this does not, how- 

 ever, exclude the well-established power of bile acids to dissolve 



