520 DIGESTION. 



SCHMITZ l has shown in man that on the administration of hydro- 

 chloric acid, producing a hyperacidity of the gastric juice, the putrefac- 

 tion in the intestine may be checked. The question arises whether the 

 reaction in the small intestine is always acid and whether the acidity 

 is strong enough to prevent putrefaction. In this connection it must 

 be recalled that the acidity of the contents of the small intestine is not 

 due to hydrochloric acid, but chiefly to organic acids, acid salts, and 

 free carbon dioxide. There are several observations as to the reaction 

 of the intestinal contents, by MOORE and ROCKWOOD, MOORE and 

 BERGIN, MATTHES and MAKQUARDSEN, I. MUNK, NENCKI and ZALESKI, 

 HEMMETER, 2 although they are somewhat contradictory. From these 

 reports one can conclude that the reaction may vary not only among 

 different animals, but also in the same animals under varying conditions. 

 There is no doubt that the acid reaction in many cases is due to the pres- 

 ence of organic acids. On testing with various indicators it has been 

 shown that sometimes the upper parts, and often the lower parts, are 

 acid, due to acid salts such as NaHCOs and free C02, and finally that 

 in certain animals the intestinal contents are alkaline throughout. The 

 question how, under these conditions, putrefaction is excluded, and how 

 the acidity of the gastric contents influences the intestinal putrefaction, 

 cannot be explained. It is very probable that the bacterial flora of the 

 intestine is of very great importance and it is possible, as BIENSTOCK 

 admits, that the explanation lies in an antagonistic bacterial action and 

 that the carbohydrates, especially lactose, which retard putrefaction, 

 form a good nutritive media for those bacteria which destroy the putre- 

 factive producers or retard their development. According to HORO- 

 WITZ an unequal division of the various bacteria occurs in dogs in the 

 different parts of the intestine and certain varieties of bacteria occur 

 in greater quantities than others, according to the kind of food taken. 

 The influence of the kind of food upon the intestinal flora has also been 

 studied by KENDALL. Perhaps, also, agreeing with the experience of 

 CONRADI and KURPJUWEIT, S the toxins produced by the intestinal bacteria 

 may, by their antiseptic action, keep the putrefactive processes in the 

 intestine within bounds. 



1 Zeitschr. f. physiol. Chem., 19, 401, which includes all the pertinent literature. 



2 Moore and Rockwood, Journ. of Physiol., 21; Moore and Bergin, Amer. Journ. 

 of Physiol., 3; Matthes and Marquardsen, Maly's Jahresber., 28; Munk, Centralbl. f. 

 Physiol., 16; Nencki and Zaleski, Zeitschr. f. physiol. Chem., 27; Hemmeter, Pfliiger's 

 Arch., 81. 



3 Bienstock, Arch. f. Hygiene, 39; Horowitz. Zeitschr. f. physiol. Chem., 52; Ken- 

 dall, Journ. of biol. Chem. 6, 499 (1909); Conradi and Kurpjuweit, Munch, med. 

 Wochenschr., 1905. 



