THE FERMENTATIVE AND PUTREFACTIVE PRO- 

 CESSES FROM THE STANDPOINT OF THEIR 

 PRODUCTS 



IT is helpful to review the fermentative and putrefac- 

 tive processes in the digestive tract of man from the 

 standpoint of their products although such a course may 

 somewhat temper enthusiasm by revealing our ignorance 

 in many important directions. I shall use the word 

 "fermentative" to designate the decompositions of car- 

 bohydrate and fatty substances and the word "putre- 

 factive " as applied to the cleavages of proteid and allied 

 substances. The distinction is important, for while the 

 products of fermentation are in themselves usually 

 unimportant as agents of intoxication, the products of 

 putrefaction include substances containing sulphur or 

 nitrogen or both sulphur and nitrogen, and thus frequently 

 derive a chemical basis for exerting toxic effects. While 

 making this distinction, however, I do not lose sight of 

 the fact that fermentative and putrefactive processes 

 overlap in the sense that they furnish some products 

 in common, such as carbon dioxide and volatile fatty 

 acids ; they are moreover closely linked by the fact that 

 excessive fermentation in the digestive tract nearly 

 always leads to excessive putrefaction, for reasons which 

 I hope to make clear. 



The products of fermentative decomposition in the 



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