120 INFECTIONS OF THE DIGESTIVE TRACT 



study of the human faeces, but I believe it has here an 

 important clinical application. Although it is true that 

 B. aerogenes capsulatus can be isolated from the fseces 

 of a majority of adult individuals, including very many 

 who are in excellent health, it is also true that there are 

 wide differences in the number of capsulati habitually 

 present in the case of different individuals. There are 

 some young persons between the ages of five and twenty 

 years from whom it is either very difficult to obtain 

 B. aerogenes capsulatus by plating or whose movements 

 give no evidence whatever of its presence. If we pre- 

 pare a suspension of the fseces from such individuals by 

 grinding one gram of the fresh material with nine cubic 

 centimeters of 0.85 per cent, salt solution and filtering 

 through absorbent cotton, we can inject intravenously 

 one or two cubic centimeters of this suspension into a 

 rabbit and then incubate the quickly killed rabbit for 

 five hours at 37 C. without obtaining evidence of the 

 abundant presence of the gas-bacillus. On opening a 

 rabbit which has been thus incubated, one finds none of 

 the signs of the activity of the gas-bacillus no accu- 

 mulation of gas in the liver or vessels or in the con- 

 nective tissues or serous cavities. Moreover, smears made 

 from the liver blood or the auricular blood either do not 

 show the presence of capsulatus at all, or these organisms 

 are present only in small numbers. If, however, the 

 foregoing experiment be made with the fsecal material 

 derived from a patient with pernicious anaemia or from a 

 person suffering from a capsulatus diarrhoea, one gener- 

 ally gets an entirely different result. At the end of five 



