220 LECTURE X. 



the carbohydrates, whose fermentation is an especially vigorous one when 

 the free hydrochloric acid is absent, as is indicated by the appearance of 

 butyric and lactic acids in such cases. The antiseptic action of hydro- 

 chloric acid is, therefore, more to be sought for in this direction. 



To the bile, and especially the acid present in it, has also been ascribed 

 an influence on the putrefactive changes in the intestines. There are, 

 however, many observations which do not support this view. Friedrich 

 Miiller * observed no increase in the amount of indican excreted in a case 

 of icterus, i.e. an obstruction in the biliary passages, thus preventing the 

 flowing of bile into the intestine; nor was there any appreciable increase 

 in putrefactive changes observed in the case of a dog in which a biliary 

 fistula was made. 



The putrefactive processes increase in the intestines only when some 

 stagnation of the intestinal contents exists. Jaffe, who first called 

 attention to this phenomenon, also showed that only when a stoppage 

 occurred in the small intestine did any marked increase of indican appear 

 in the urine. If we observe any increase in the elimination of indican, 

 and there is an obstruction in the large intestine, we are, therefore, justi- 

 fied in concluding that the stoppage reacts back upon the contents of 

 the smaller intestine. That a stoppage of the large intestine of itself has 

 but little effect upon the elimination of indican, is evident from the fact 

 that the greater part of the albumin is absorbed in the small intestine, 

 while only small amounts, depending on the nature of the food, succeed 

 in reaching the large intestine. Ellinger and Prutz 2 have determined the 

 effect of stoppages in various parts of the alimentary tract in a very 

 ingenious manner. They cut out pieces of the intestine of a dog, and 

 replaced them so that the oral end of each excised piece was joined to 

 the distal end of the whole intestine; and, conversely, the distal end was 

 joined to the portion remaining attached to the stomach. Such a piece 

 of intestine retains its original peristalsis and prevents the further pro- 

 gress of the chyme and faeces, in that it continually opposes the activity 

 of the remainder of the intestine. We shall subsequently take up in detail 

 the compounds resulting from the putrefactive processes upon the cleavage- 

 products of albumin. 



1 Z. klin. Med. 12. 



1 Z. physiol. Chem. 38, 399 (1903). 



