8 



THE BACTERIOPHAGE AND ITS BEHAVIOR 



an extremely marked antiseptic action for bacteria in general, and for 

 the cholera vibrio in particular. Thus, the water of the Jumna, as 

 it left the town of Agra, contained more than 100,000 bacteria per 

 cubic centimeter, while some 5 kilometers further down the bacterial 

 count was reduced to but 90 to 100 organisms. 



Dealing more particularly with the cholera vibrio, his laboratory 

 findings gave the results presented in the following table. In this 

 table the first line shows the effect of the Jumna river water after 

 filtration. The figures of the second line represent the action of the 

 same filtered water after boiling. In both instances, the water had 

 been inoculated with a culture of V. cholerae, and the rate of action is 

 shown by the bacterial counts made after different intervals. 



The germicidal action of the water of these rivers could always be 

 detected, but it was not uniform in degree. 



It is of interest that it is to this antiseptic action that Hankin attrib- 

 utes the fact that he never was able to demonstrate that the ingestion 

 of the water of these rivers was responsible for the development of a 

 single case of cholera. Certainly these rivers were never the carriers of 

 epidemics; cholera always spreads from down-stream upwards. 



Hankin showed that the antiseptic principle was destroyed by boil- 

 ing, and, from his experiments, he deduced that it was volatile. 



Flu^^" denies that the bacteriophage was the agency responsible for 

 this germicidal action, since Hankin had shown that a volatile sub- 

 stance was involved. It is certain that if this statement of Hankin is 

 correct, it by itself suffices to prove that the bacteriophage was not 

 involved. As a matter of fact the experiment on volatihzation offers 

 abundant chance for error, and we shall see that this error has con- 

 tributed to the results of some investigators who have considered the 

 question of the volatile nature of the bacteriophage. The error Hes 

 in the fact that when distillation is carried out at low temperatures, 

 without special precautions, materials are carried over into the dis- 

 tillate, leading to the erroneous conclusion that a volatilization has 



