INFECTIONS OF THE DIGESTIVE TRACT 297 



putrefying material in the intestine, but it must be ad- 

 mitted that the facts bearing on this point are not con- 

 clusive. Outside the body the mixed fsecal flora from 

 cases of excessive saccharo-butyric putrefaction is usu- 

 ally capable of forming mercaptan on peptone bouillon 

 and in some cases the amount produced hi twenty-four 

 hours is sufficient to give a very strong reaction in the 

 isatin-sulphuric-acid tube. This condition is unphysio- 

 logical, as it is not observed in most adults in good 

 health. A moderate mercaptan reaction is often ob- 

 tained, as already stated, through the action of the 

 mixed fsecal flora derived from apparently healthy 

 young children. That the reaction is abnormal is 

 shown not merely by the infrequency of its occurrence 

 in healthy adults, but also by the fact that a patient 

 when improving from conditions of marked saccharo- 

 butyric putrefaction will usually lose the flora capable 

 of making methyl mercaptan in peptone bouillon. A 

 satisfactory explanation of the formation of methyl 

 mercaptan by the mixed fsecal flora cannot yet be offered. 

 It is easy to show that B. putrificus is able to form methyl 

 mercaptan, and in some cases of saccharo-butyric pu- 

 trefaction B. putrificus occurs abundantly, especially in 

 peptone bouillon to which has been added magnesium 

 or calcium carbonate. In such instances it would 

 appear that the methyl mercaptan is formed as a result 

 of the activity of B. putrificus. There are other cases, 

 however, in which, although methyl mercaptan is 

 formed by the mixed fsecal flora, one fails to obtain 

 B. putrificus, and hence the reaction cannot confidently 



