L>52 BACTERIOLOGICAL EXAMINATION OF WATER. 



This table shows that there is no constant vaccinal reciprocity 

 between the vibrios derived from different sources. Even in the 

 case of the true cholera vibrios the spirillum from Courbevoie did 

 not confer immunity against the spirillum from Angers, and 

 vice versa. 



Sanarelli also made experiments to see the effect of placing 

 the Vibrio Saint-Cloud under conditions closely resembling those 

 found in nature. Two flasks were filled with water from the 

 Seine at Clichy and then sterilised at 120 C. Some drops of a 

 culture of the Vibrio Saint-Cloud were then added to each flask, 

 one of which was kept at the room temperature (20 24 C.) 

 and the other placed in ice at 5-10 C. After a month the 

 vibrio was again isolated from the flasks, and it was found that 

 the vibrio from the first flask showed a feeble cholera-red 

 reaction, as compared with the original culture, and in the case 

 of the vibrio from the second flask the cholera-red reaction 

 was almost imperceptible. Both vibrios had also completely 

 lost their virulence, intra-peritoneal injections into guinea-pigs 

 of large doses of the microbes producing no effect. A specimen 

 of the water at Saint Cloud, from which the Vibrio Saint-Cloud 

 was isolated, was kept at the room temperature for three months. 

 Vibrios were then isolated from the water, but the new specimens 

 gave no indol reaction, liquefied gelatine much more slowly than 

 before, and had no pathogenic action on animals. 



Kohlbrugge quite recently investigated water from an arm 

 of the Rhine at Utrecht (free from cholera for seven years), 

 and found vibrios present during every month in the year ; but 

 whereas the vibrios isolated in the summer months gave a 

 marked cholera-red colour, those isolated in the winter failed to 



