PUTREFACTION IN THE INTESTINE. 515 



putrefaction of the proteins is not the same as the pancreatic digestion. 

 In putrefaction the decomposition goes much further, and a mixture of 

 products is obtained which have become known through the labors 

 of numerous investigators, especially NENCKI, BAUMANN, BRIEGER, H. 

 and E. SALKOWSKI, and their pupils. The products which are formed 

 in the putrefaction of proteins are (in addition to proteases, peptones, 

 amino-adds, and ammonia) indol, skatol, paracresol, phenol, phenylpro- 

 pionic add, and phenylacetic add, also paraoxyphenylacetic add and 

 hydroparacoumaric add (besides paracresol, produced in the putrefaction 

 of tyrosin), volatile fatty adds, carbon dioxide, hydrogen, marsh-gas, 

 methylmercaptan, and sulphureted hydrogen. In the putrefaction of 

 gelatin neither tyrosine nor indol is formed, while glycocoll is produced 

 instead. 



Among these products of decomposition a few are of special interest 

 because of their behavior within the organism and because after their 

 absorption they, pass into the urine. A few, such as the oxyacids, pass 

 unchanged into the urine. Others, such as phenols, are directly trans- 

 formed into ethereal sulphuric acids by synthesis, and are eliminated as 

 such by the urine; on the contrary, others, such as indol and skatol, are 

 converted into ethereal sulphuric acids after oxidation only (for details 

 see Chapter XIV). The quantity of these bodies in the urine also varies 

 with the extent of the putrefactive processes in the intestine; at least 

 this is true for the ethereal sulphuric acids. Their quantity increases 

 in the urine with a stronger putrefaction, and the reverse takes place, 

 namely, a disappearance from the urine, or a great reduction in quantity, 

 as BAUMANN, HARLEY and GOODBODY 1 have shown by experiments 

 on dogs, when the intestine is disinfected by various agents. 



The gases which are produced by the decomposition processes are 

 mixed in the intestinal tract with the atmospheric air swallowed with 

 the saliva and food, and as the gas developed in the decomposition of 

 different foods varies, so the mixture of gases after various foods should 

 have a dissimilar composition. This is found to be true. Oxygen is 

 found only in very faint traces in the intestine; this may be accounted 

 for in part by the formation of reducing substances in the fermenta- 

 tion processes which combine with the oxygen, and partly, perhaps 

 chiefly, to a diffusion of the oxygen through the tissues of the walls of 

 the intestine. To show that these processes take place mainly in the 

 stomach, the reader is referred to page 486, on the composition of the 

 gases of the stomach. Nitrogen is invariably found in the intestine, 

 and it is probably due chiefly to the swallowed air. The carbon dioxide 



^aumann, Zeitschr. f. physiol. Chem., 10; Harley and Goodbody, Brit. Med. 

 Journ., 1899. 



