CHANGES IN INTESTINES. THE FECES. 1 95 



of fermentation being themselves partly absorbed, the activity 

 of the putrefactive organisms gains the upper hand and large 

 numbers of complex reactions follow. The nature of some of 

 the bodies produced in this way has been already referred to 

 and further facts may now be given. In laboratory experi- 

 ments on pancreatic digestion it will be recalled that two gen- 

 eral results are obtainable. In working with the pancreas or 

 pancreatic extract plus fibrin or casein we add thymol or chlor- 

 oform water if it is desired to secure the maximum enzymic 

 effect, but if, on the contrary, the bacterial as well as the en- 

 zymic decompositions are desired this protective addition is 

 omitted and putrefaction soon becomes apparent. In the ani- 

 mal body the acid fermentation products take the place in a 

 measure of the chloroform or other substances used in the 

 laboratory experiments. Indol and skatol have been already 

 referred to as characteristic disintegration products resulting 1 

 from the action of bacteria on proteins ; there are many others 

 in addition to these, and most of them are compounds of the 

 aromatic group. Under the conditions of their appearance in 

 the intestines these disintegration residues must be largely 

 formed from the albumoses, peptones, leucine and tyrosine of 

 the previous enzymic digestions; in comparatively rare cases 

 it is possible that the putrefaction may take place with portions 

 of left-over original proteins which for some reason escaped 

 digestion proper. Phenol, paracresol, phenylacetic acid, phe- 

 nylpropionic acid, para-oxyphenylacetic acid, glycocoll, methyl 

 mercaptan, hydrogen sulphide, marsh gas and still other sub- 

 stances, including various volatile fatty acids and carbon diox- 

 ide, have been found here along with the indol and skatol. 

 These various products are produced mainly in the large intes- 

 tine, and here again we find certain limitations to the extent 

 of the reactions. Through the small intestine the contents 

 have remained very soft and liquid, but in the large intestine 

 normally a marked absorption of water takes place, from 

 which the contents become thick and at times almost hard. 

 This loss of water interferes greatly with the progress of 



