200 MICROBES, FERMENTS, AND MOULDS. 



cultivated in distilled water die within twelve hours, 

 while they can live for a week in drinking-water. 

 (Cornil.) 



The influence of the level of the subterranean 

 waters on the progress of cholera epidemics was 

 pointed out in Germany by Pettenkofer long before 

 there was any serious idea of regarding a microbe as 

 the cause. 



During his recent travels in India, Koch met with 

 the comma bacillus in the stagnant waters of that 

 country. 



For a long while the attempt failed to reproduce 

 Asiatic cholera in animals by injections of comma 

 bacilli, and thus to prove the parasitic nature of the 

 disease. The animals in countries attacked by cholera 

 appear to enjoy immunity in this respect. Nicati and 

 Rietsch at Marseilles were, however, successful in pro- 

 ducing cholera by the direct injection of choleraic liquid 

 into the duodenum of guinea-pigs, dogs, etc. Almost 

 all these animals died at the end of two or three days, 

 and the inflamed intestines contained a number of 

 comma bacilli, much more vigorous than those of the 

 injection. 



Bochefontaine, of Paris, swallowed pills which 

 contained choleraic evacuations. He felt unwell for 

 some days, but no serious consequences ensued. It 

 is probable that in this case the acidity of the gastric 

 juice attenuated, or partially destroyed the bacilli. 

 We shall see that acids are, in fact, adverse to the 



