ISO THE BACTERIA IN ASIATIC CHOLERA. [CH. 



utensils, and in many cases using the water even for drinking. 

 This latter is not the rule, since many fetch their drinking- 

 water from the hydrants, of which there are many in all 

 parts of the city. But there can be no doubt, as inquiry 

 proves, that the water of the tanks is used also for drinking 

 purposes. And yet isolated cases may occur in one of 

 these bustees during parts of the year without being followed 

 by other cases. Calcutta is not an isolated instance, the 

 same holds good of almost every city in Bengal ; in Bombay 

 and Benares, when I happened to be there in September 

 and October 1884, I had ample opportunity of studying 

 these facts, and they have been mentioned in the Report of 

 the English Cholera Commission, published by the India 

 Office (pp. 28, 29). 



There is not a locality in India, in which, owing to the 

 just-mentioned habits of the natives, cholera, once imported, 

 might not be expected to develop into an epidemic; yet 

 this is often not the case. Cases of cholera have been 

 imported by pilgrims and others coming from an infected 

 locality, and while at a certain time of the year, say from 

 March till June, it led to an epidemic, during other times of 

 the year it did no such thing. The same dependence on 

 seasons as regards Europe is well known, and has been very 

 fully discussed and demonstrated by von Pettenkofer. 



The notorious dependence of the spread of cholera on 

 season is, I think, irreconcilable with the facts that are 

 known concerning the comma-bacilli. The comma-bacilli 

 grow and multiply well at all temperatures between 16 and 

 40 C. I have had good cultures growing at 16 C., and 

 therefore the months of August, September, October, and 

 November in India would be extremely favourable. In the 

 south of Europe March and October, or even February and 

 November, would be quite favourable, yet these are, as a 



